WorldWideScience

Sample records for power law led

  1. Human learning: Power laws or multiple characteristic time scales?

    Directory of Open Access Journals (Sweden)

    Gottfried Mayer-Kress

    2006-09-01

    Full Text Available The central proposal of A. Newell and Rosenbloom (1981 was that the power law is the ubiquitous law of learning. This proposition is discussed in the context of the key factors that led to the acceptance of the power law as the function of learning. We then outline the principles of an epigenetic landscape framework for considering the role of the characteristic time scales of learning and an approach to system identification of the processes of performance dynamics. In this view, the change of performance over time is the product of a superposition of characteristic exponential time scales that reflect the influence of different processes. This theoretical approach can reproduce the traditional power law of practice – within the experimental resolution of performance data sets - but we hypothesize that this function may prove to be a special and perhaps idealized case of learning.

  2. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  3. LED power consumption in joint illumination and communication system

    NARCIS (Netherlands)

    Deng, X.; Wu, Y.; Khalid, A.M.; Long, X.; Linnartz, J.-P.M.G.

    This paper addresses the power penalty in an illumination LED caused by visible light communication (VLC). This study models the extra power consumption of the LED by taking into account the convex relation between the dissipated electrical power versus the LED current on one hand and the concave

  4. High power blue LED development using different growth modes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong S.; Florescu, Doru I.; Ramer, Jeff C.; Merai, Vinod; Parekh, Aniruddh; Begarney, Michael J.; Armour, Eric A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); Lu Dong [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); School of Engineering, Rutgers University, Piscataway, NJ 08854 (United States)

    2004-09-01

    Blue high brightness light emitting diodes (HB-LEDs) have been developed using different growth modes in the active layers. Piezoelectric field engineering improves the optical output power in multiple quantum well (MQW) LEDs by inserting an optimized transitional superlattice (TSL) before the active MQW layers. Within single quantum well (SQW) LEDs, quasi-Quantum Dot (QD) growth for Indium localization has been realized. The SQW LED output power exceeds the strain engineered MQW LEDs. The experimental data indicates that Indium localization enhances overall quantum efficiency and results in increased output power for HB-LEDs. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Fractional power-law spatial dispersion in electrodynamics

    International Nuclear Information System (INIS)

    Tarasov, Vasily E.; Trujillo, Juan J.

    2013-01-01

    Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb’s law and Debye’s screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type. -- Highlights: •Plasma-like non-local media with power-law spatial dispersion. •Fractional differential equations for electric fields in the media. •The generalizations of Coulomb’s law and Debye’s screening for the media

  6. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  7. Quantum dissipation from power-law memory

    International Nuclear Information System (INIS)

    Tarasov, Vasily E.

    2012-01-01

    A new quantum dissipation model based on memory mechanism is suggested. Dynamics of open and closed quantum systems with power-law memory is considered. The processes with power-law memory are described by using integration and differentiation of non-integer orders, by methods of fractional calculus. An example of quantum oscillator with linear friction and power-law memory is considered. - Highlights: ► A new quantum dissipation model based on memory mechanism is suggested. ► The generalization of Lindblad equation is considered. ► An exact solution of generalized Lindblad equation for quantum oscillator with linear friction and power-law memory is derived.

  8. Zipf's law, power laws and maximum entropy

    International Nuclear Information System (INIS)

    Visser, Matt

    2013-01-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified. (paper)

  9. Power Laws are Disguised Boltzmann Laws

    Science.gov (United States)

    Richmond, Peter; Solomon, Sorin

    Using a previously introduced model on generalized Lotka-Volterra dynamics together with some recent results for the solution of generalized Langevin equations, we derive analytically the equilibrium mean field solution for the probability distribution of wealth and show that it has two characteristic regimes. For large values of wealth, it takes the form of a Pareto style power law. For small values of wealth, wGeneralized Lotka-Volterra type of stochastic dynamics. The power law that arises in the distribution function is identified with new additional logarithmic terms in the familiar Boltzmann distribution function for the system. These are a direct consequence of the multiplicative stochastic dynamics and are absent for the usual additive stochastic processes.

  10. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  11. Stochastic model of Zipf's law and the universality of the power-law exponent.

    Science.gov (United States)

    Yamamoto, Ken

    2014-04-01

    We propose a stochastic model of Zipf's law, namely a power-law relation between rank and size, and clarify as to why a specific value of its power-law exponent is quite universal. We focus on the successive total of a multiplicative stochastic process. By employing properties of a well-known stochastic process, we concisely show that the successive total follows a stationary power-law distribution, which is directly related to Zipf's law. The formula of the power-law exponent is also derived. Finally, we conclude that the universality of the rank-size exponent is brought about by symmetry between an increase and a decrease in the random growth rate.

  12. Power laws in Ising nanostripes

    International Nuclear Information System (INIS)

    Drzewinski, A.; Sznajd, J.; Szota, K.

    2005-01-01

    The results of high accuracy density-matrix renormalization-group calculations for infinite Ising stripes of finite widths 100 ≤ L ≤ 400 are presented. It is shown that in the presence of the small external magnetic field the infinite system critical power laws can be observed for L of order hundreds nm. The single power law describes the field dependence of the magnetization or the longitudinal correlation length only on the infinite system critical isotherm independently of the value of L. The approximate power law which describes how the magnetization varies with a distance from the infinite system critical point for several directions in the plane (temperature, external field) is also studied. (author)

  13. Direct battery-driven solar LED lighting using constant-power control

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.

  14. PV power system using hybrid converter for LED indictor applications

    International Nuclear Information System (INIS)

    Tseng, Sheng-Yu; Wang, Hung-Yuan; Chen, Chien-Chih

    2013-01-01

    Highlights: • This paper presents a LED indictor driving circuit with a PV arrays as its power source. • The perturb-and-observe method is adopted to extract the maximum power of PV arrays. • The proposed circuit structure has a less component counts and higher conversion efficiency. • A prototype of LED indictor driving circuit has been implemented to verify its feasibility. • The proposed hybrid converter is suitable for LED inductor applications. - Abstract: This paper presents a LED indictor driving circuit with a PV arrays as its power source. The LED indictor driving circuit includes battery charger and discharger (LED driving circuit). In this research, buck converter is used as a charger, and forward converter with active clamp circuit is adopted as a discharger to drive the LED indictor. Their circuit structures use switch integration technique to simplify them and to form the proposed hybrid converter, which has a less component counts, lighter weight, smaller size, and higher conversion efficiency. Moreover, the proposed hybrid converter uses a perturb-and-observe method to extract the maximum power from PV arrays. Finally, a prototype of an LED indictor driving circuit with output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the LED inductor applications

  15. Power laws in citation distributions: evidence from Scopus.

    Science.gov (United States)

    Brzezinski, Michal

    Modeling distributions of citations to scientific papers is crucial for understanding how science develops. However, there is a considerable empirical controversy on which statistical model fits the citation distributions best. This paper is concerned with rigorous empirical detection of power-law behaviour in the distribution of citations received by the most highly cited scientific papers. We have used a large, novel data set on citations to scientific papers published between 1998 and 2002 drawn from Scopus. The power-law model is compared with a number of alternative models using a likelihood ratio test. We have found that the power-law hypothesis is rejected for around half of the Scopus fields of science. For these fields of science, the Yule, power-law with exponential cut-off and log-normal distributions seem to fit the data better than the pure power-law model. On the other hand, when the power-law hypothesis is not rejected, it is usually empirically indistinguishable from most of the alternative models. The pure power-law model seems to be the best model only for the most highly cited papers in "Physics and Astronomy". Overall, our results seem to support theories implying that the most highly cited scientific papers follow the Yule, power-law with exponential cut-off or log-normal distribution. Our findings suggest also that power laws in citation distributions, when present, account only for a very small fraction of the published papers (less than 1 % for most of science fields) and that the power-law scaling parameter (exponent) is substantially higher (from around 3.2 to around 4.7) than found in the older literature.

  16. Power law scaling for rotational energy transfer

    International Nuclear Information System (INIS)

    Pritchard, D.E.; Smith, N.; Driver, R.D.; Brunner, T.A.

    1979-01-01

    We have applied a new scaling law to several sets of rotational energy transfer cross sections. The new law asserts that the square of the T-matrix depends on the amount of energy transferred as a power law. Two different kinds of angular momentum statistics are assumed, one corresponding to m/sub j/ being conserved and the other corresponding to m/sub j/ being completely randomized. Numerical fits are presented which demonstrate that the data follow the power law better than the widely used exponential gap law

  17. Visiting Power Laws in Cyber-Physical Networking Systems

    Directory of Open Access Journals (Sweden)

    Ming Li

    2012-01-01

    Full Text Available Cyber-physical networking systems (CPNSs are made up of various physical systems that are heterogeneous in nature. Therefore, exploring universalities in CPNSs for either data or systems is desired in its fundamental theory. This paper is in the aspect of data, aiming at addressing that power laws may yet be a universality of data in CPNSs. The contributions of this paper are in triple folds. First, we provide a short tutorial about power laws. Then, we address the power laws related to some physical systems. Finally, we discuss that power-law-type data may be governed by stochastically differential equations of fractional order. As a side product, we present the point of view that the upper bound of data flow at large-time scaling and the small one also follows power laws.

  18. Helmholtz solitons in power-law optical materials

    International Nuclear Information System (INIS)

    Christian, J. M.; McDonald, G. S.; Potton, R. J.; Chamorro-Posada, P.

    2007-01-01

    A nonlinear Helmholtz equation for optical materials with regimes of power-law type of nonlinearity is proposed. This model captures the evolution of broad beams at any angle with respect to the reference direction in a wide range of media, including some semiconductors, doped glasses, and liquid crystals. Exact analytical soliton solutions are presented for a generic nonlinearity, within which known Kerr solitons comprise a subset. Three general conservation laws are also reported. Analysis and numerical simulations examine the stability of the Helmholtz power-law solitons. A propagation feature, associated with spatial solitons in power-law media, constituting a class of oscillatory solution, is identified

  19. Development of constant-power driving control for light-emitting-diode (LED) luminaire

    International Nuclear Information System (INIS)

    Huang, Bin-Juine; Chen, Chun-Wei; Ong, Chin-Dian; Du, Bo-Han; Hsu, Po-Chien

    2013-01-01

    The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (−1.7%) for constant-power driving, as compared to that of constant-current driving (−12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. - Highlights: ► A constant-power driving technique is proposed for LED luminaire. ► A linear system dynamics model of LED luminaire is used in the control system design. ► The test shows that the feedback system accurately controls the input power. ► The LED illumination varies slightly (−1.7%) for constant-power driving.

  20. Power series like relation of power law and coupled creep ...

    African Journals Online (AJOL)

    When a solid deforms at high temperature its microstructure may in some sense be altered- holes and cracks may nucleate and grow inside the solid by various mechanism controlled by diffusion and by power law creep or by a combination of these mechanisms. Considering a coupled diffusion power law creep mechanism ...

  1. Direct battery-driven solar LED lighting using constant-power control

    KAUST Repository

    Huang, Bin-Juine; Chen, Chun-Wei; Hsu, Po-Chien; Tseng, Wei-Min; Wu, Min-Sheng

    2012-01-01

    A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result

  2. The speed-curvature power law of movements: a reappraisal.

    Science.gov (United States)

    Zago, Myrka; Matic, Adam; Flash, Tamar; Gomez-Marin, Alex; Lacquaniti, Francesco

    2018-01-01

    Several types of curvilinear movements obey approximately the so called 2/3 power law, according to which the angular speed varies proportionally to the 2/3 power of the curvature. The origin of the law is debated but it is generally thought to depend on physiological mechanisms. However, a recent paper (Marken and Shaffer, Exp Brain Res 88:685-690, 2017) claims that this power law is simply a statistical artifact, being a mathematical consequence of the way speed and curvature are calculated. Here we reject this hypothesis by showing that the speed-curvature power law of biological movements is non-trivial. First, we confirm that the power exponent varies with the shape of human drawing movements and with environmental factors. Second, we report experimental data from Drosophila larvae demonstrating that the power law does not depend on how curvature is calculated. Third, we prove that the law can be violated by means of several mathematical and physical examples. Finally, we discuss biological constraints that may underlie speed-curvature power laws discovered in empirical studies.

  3. Power-law-lapse time gauges

    International Nuclear Information System (INIS)

    Jantzen, R.T.

    1988-01-01

    The choice of time function for cosmological solutions of gravitational field equations is related to the action of the group of independent scale transformations of the unit of length along orthogonal spatial directions. This is accomplished by the introduction of lapse functions which depend explicitly on the spatial metric in an appropriately defined power-law fashion. The resulting power-law-lapse time gauges are the key to producing nearly all exact solutions of the class of models for which the field equations reduce to ordinary differential equations

  4. Scaling laws for fractional Brownian motion with power-law clock

    International Nuclear Information System (INIS)

    O'Malley, Daniel; Cushman, John H; Johnson, Graham

    2011-01-01

    We study the mean first passage time (MFPT) for fractional Brownian motion (fBm) in a finite interval with absorbing boundaries at each end. Analytical arguments are used to suggest a simple scaling law for the MFPT and numerical experiments are performed to verify its accuracy. The same approach is used to derive a scaling law for fBm with a power-law clock (fBm-plc). The MFPT scaling laws are employed to develop scaling laws for the finite-size Lyapunov exponent (FSLE) of fBm and fBm-plc. We apply these results to diffusion of a large polymer in a region with absorbing boundaries. (letter)

  5. Automated image enhancement using power law transformations

    Indian Academy of Sciences (India)

    We propose a scheme for automating power law transformations which are used for image enhancement. The scheme we propose does not require the user to choose the exponent in the power law transformation. This method works well for images having poor contrast, especially to those images in which the peaks ...

  6. Tomographic Particle Image Velocimetry using Pulsed, High Power LED Volume Illumination

    OpenAIRE

    Buchmann, N. A.; Willert, C.; Soria, J.

    2011-01-01

    This paper investigates the use of high-power light emitting diode (LED) illumination in Particle Image Velocimetry (PIV) as an alternative to traditional laser-based illumination. The solid-state LED devices can provide averaged radiant power in excess of 10W and by operating the LEDs with short current pulses, considerably higher than in continuous operation, light pulses of sufficient energy suitable for imaging micron-sized particles can be generated. The feasibility of this LED-based ill...

  7. Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

    Science.gov (United States)

    Cheng, W.; Samtaney, R.

    2014-01-01

    The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can not provide sufficient clues, in this study we present an insight into this debate from a large-eddy simulation (LES) viewpoint. The LES organically combines state-of-the-art models (the stretched-vortex model and inflow rescaling method) with a virtual-wall model derived under different scaling law assumptions (the log-law or the power-law by George and Castillo ["Zero-pressure-gradient turbulent boundary layer," Appl. Mech. Rev. 50, 689 (1997)]). Comparison of LES results for Reθ ranging from 105 to 1011 for zero-pressure-gradient turbulent boundary layer flows are carried out for the mean streamwise velocity, its gradient and its scaled gradient. Our results provide strong evidence that for both sets of modeling assumption (log law or power law), the turbulence gravitates naturally towards the log-law scaling at extremely large Reynolds numbers.

  8. Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

    KAUST Repository

    Cheng, W.

    2014-01-29

    The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can not provide sufficient clues, in this study we present an insight into this debate from a large-eddy simulation (LES) viewpoint. The LES organically combines state-of-the-art models (the stretched-vortex model and inflow rescaling method) with a virtual-wall model derived under different scaling law assumptions (the log-law or the power-law by George and Castillo [“Zero-pressure-gradient turbulent boundary layer,” Appl. Mech. Rev.50, 689 (1997)]). Comparison of LES results for Re θ ranging from 105 to 1011 for zero-pressure-gradient turbulent boundary layer flows are carried out for the mean streamwise velocity, its gradient and its scaled gradient. Our results provide strong evidence that for both sets of modeling assumption (log law or power law), the turbulence gravitates naturally towards the log-law scaling at extremely large Reynolds numbers.

  9. Power laws in the information production process Lotkaian informetrics

    CERN Document Server

    Egghe, Leo

    2005-01-01

    Explains many informetric regularities, only based on a decreasing power law as size-frequency function, that is Lotka''s law. This book revives the historical formulation of Alfred Lotka and shows the power of this power law, both in classical aspects of informetrics as well as in applications such as social networks and others.

  10. Power law analysis of the human microbiome.

    Science.gov (United States)

    Ma, Zhanshan Sam

    2015-11-01

    Taylor's (1961, Nature, 189:732) power law, a power function (V = am(b) ) describing the scaling relationship between the mean and variance of population abundances of organisms, has been found to govern the population abundance distributions of single species in both space and time in macroecology. It is regarded as one of few generalities in ecology, and its parameter b has been widely applied to characterize spatial aggregation (i.e. heterogeneity) and temporal stability of single-species populations. Here, we test its applicability to bacterial populations in the human microbiome using extensive data sets generated by the US-NIH Human Microbiome Project (HMP). We further propose extending Taylor's power law from the population to the community level, and accordingly introduce four types of power-law extensions (PLEs): type I PLE for community spatial aggregation (heterogeneity), type II PLE for community temporal aggregation (stability), type III PLE for mixed-species population spatial aggregation (heterogeneity) and type IV PLE for mixed-species population temporal aggregation (stability). Our results show that fittings to the four PLEs with HMP data were statistically extremely significant and their parameters are ecologically sound, hence confirming the validity of the power law at both the population and community levels. These findings not only provide a powerful tool to characterize the aggregations of population and community in both time and space, offering important insights into community heterogeneity in space and/or stability in time, but also underscore the three general properties of power laws (scale invariance, no average and universality) and their specific manifestations in our four PLEs. © 2015 John Wiley & Sons Ltd.

  11. Development of constant-power driving control for light-emitting-diode (LED) luminaire

    KAUST Repository

    Huang, Bin-Juine

    2013-01-01

    The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (-1.7%) for constant-power driving, as compared to that of constant-current driving (-12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. © 2012 Elsevier Ltd. All rights reserved.

  12. A high-performance stand-alone solar PV power system for LED lighting

    KAUST Repository

    Huang, B. J.

    2010-06-01

    The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED is directly driven by battery using a PWM discharge control to eliminate a DC/DC converter. Two solar-powered LED lighting systems (50W and 100W LED) were built. The long-term outdoor tests have shown that the loss of load probability for full-night lighting requirement is zero for 50W LED and 3.6% for 100W LED. © 2010 IEEE.

  13. Testing a high-power LED based light source for hyperspectral imaging microscopy

    Science.gov (United States)

    Klomkaew, Phiwat; Mayes, Sam A.; Rich, Thomas C.; Leavesley, Silas J.

    2017-02-01

    Our lab has worked to develop high-speed hyperspectral imaging systems that scan the fluorescence excitation spectrum for biomedical imaging applications. Hyperspectral imaging can be used in remote sensing, medical imaging, reaction analysis, and other applications. Here, we describe the development of a hyperspectral imaging system that comprised an inverted Nikon Eclipse microscope, sCMOS camera, and a custom light source that utilized a series of high-power LEDs. LED selection was performed to achieve wavelengths of 350-590 nm. To reduce scattering, LEDs with low viewing angles were selected. LEDs were surface-mount soldered and powered by an RCD. We utilized 3D printed mounting brackets to assemble all circuit components. Spectraradiometric calibration was performed using a spectrometer (QE65000, Ocean Optics) and integrating sphere (FOIS-1, Ocean Optics). Optical output and LED driving current were measured over a range of illumination intensities. A normalization algorithm was used to calibrate and optimize the intensity of the light source. The highest illumination power was at 375 nm (3300 mW/cm2), while the lowest illumination power was at 515, 525, and 590 nm (5200 mW/cm2). Comparing the intensities supplied by each LED to the intensities measured at the microscope stage, we found there was a great loss in power output. Future work will focus on using two of the same LEDs to double the power and finding more LED and/or laser diodes and chips around the range. This custom hyperspectral imaging system could be used for the detection of cancer and the identification of biomolecules.

  14. Power-law Exponent in Multiplicative Langevin Equation with Temporally Correlated Noise

    Science.gov (United States)

    Morita, Satoru

    2018-05-01

    Power-law distributions are ubiquitous in nature. Random multiplicative processes are a basic model for the generation of power-law distributions. For discrete-time systems, the power-law exponent is known to decrease as the autocorrelation time of the multiplier increases. However, for continuous-time systems, it is not yet clear how the temporal correlation affects the power-law behavior. Herein, we analytically investigated a multiplicative Langevin equation with colored noise. We show that the power-law exponent depends on the details of the multiplicative noise, in contrast to the case of discrete-time systems.

  15. Spreading dynamics of power-law fluid droplets

    International Nuclear Information System (INIS)

    Liang Zhanpeng; Peng Xiaofeng; Wang Xiaodong; Lee, D-J; Su Ay

    2009-01-01

    This paper aims at providing a summary of the theoretical models available for non-Newtonian fluid spreading dynamics. Experimental findings and model predictions for a Newtonian fluid spreading test are briefly reviewed. Then how the complete wetting and partial wetting power-law fluids spread over a solid substrate is examined. The possible extension of Newtonian fluid models to power-law fluids is also discussed.

  16. Power-law relaxation in human violent conflicts

    Science.gov (United States)

    Picoli, Sergio; Antonio, Fernando J.; Itami, Andreia S.; Mendes, Renio S.

    2017-08-01

    We study relaxation patterns of violent conflicts after bursts of activity. Data were obtained from available catalogs on the conflicts in Iraq, Afghanistan and Northern Ireland. We find several examples in each catalog for which the observed relaxation curves can be well described by an asymptotic power-law decay (the analog of the Omori's law in geophysics). The power-law exponents are robust, nearly independent of the conflict. We also discuss the exogenous or endogenous nature of the shocks. Our results suggest that violent conflicts share with earthquakes and other natural and social phenomena a common feature in the dynamics of aftershocks.

  17. Deformation of a Capsule in a Power-Law Shear Flow

    Directory of Open Access Journals (Sweden)

    Fang-Bao Tian

    2016-01-01

    Full Text Available An immersed boundary-lattice Boltzmann method is developed for fluid-structure interactions involving non-Newtonian fluids (e.g., power-law fluid. In this method, the flexible structure (e.g., capsule dynamics and the fluid dynamics are coupled by using the immersed boundary method. The incompressible viscous power-law fluid motion is obtained by solving the lattice Boltzmann equation. The non-Newtonian rheology is achieved by using a shear rate-dependant relaxation time in the lattice Boltzmann method. The non-Newtonian flow solver is then validated by considering a power-law flow in a straight channel which is one of the benchmark problems to validate an in-house solver. The numerical results present a good agreement with the analytical solutions for various values of power-law index. Finally, we apply this method to study the deformation of a capsule in a power-law shear flow by varying the Reynolds number from 0.025 to 0.1, dimensionless shear rate from 0.004 to 0.1, and power-law index from 0.2 to 1.8. It is found that the deformation of the capsule increases with the power-law index for different Reynolds numbers and nondimensional shear rates. In addition, the Reynolds number does not have significant effect on the capsule deformation in the flow regime considered. Moreover, the power-law index effect is stronger for larger dimensionless shear rate compared to smaller values.

  18. Non-thermal Power-Law Distributions in Solar and Space Plasmas

    Science.gov (United States)

    Oka, M.; Battaglia, M.; Birn, J.; Chaston, C. C.; Effenberger, F.; Eriksson, E.; Fletcher, L.; Hatch, S.; Imada, S.; Khotyaintsev, Y. V.; Kuhar, M.; Livadiotis, G.; Miyoshi, Y.; Retino, A.

    2017-12-01

    Particles are accelerated to very high, non-thermal energies in solar and space plasma environments. While energy spectra of accelerated particles often exhibit a power-law and are characterized by the power-law index δ, it remains unclear how particles are accelerated to high energies and how δ is determined. Here, we review previous observations of the power-law index δ in a variety of different plasma environments with a particular focus on sub-relativistic electrons. It appears that in regions more closely related to magnetic reconnection (such as the "above-the-looptop" solar hard X-ray source and the plasma sheet in Earth's magnetotail), the spectra are typically soft (δ> 4). This is in contrast to the typically hard spectra (δuniform in the plasma sheet, while power-law distributions still exist even in quiet times. The role of magnetotail reconnection in the electron power-law formation could therefore be confounded with these background conditions. Because different regions have been studied with different instrumentations and methodologies, we point out a need for more systematic and coordinated studies of power-law distributions for a better understanding of possible scaling laws in particle acceleration as well as their universality.

  19. Power-law creep behavior of a semiflexible chain.

    Science.gov (United States)

    Majumdar, Arnab; Suki, Béla; Rosenblatt, Noah; Alencar, Adriano M; Stamenović, Dimitrije

    2008-10-01

    Rheological properties of adherent cells are essential for their physiological functions, and microrheological measurements on living cells have shown that their viscoelastic responses follow a weak power law over a wide range of time scales. This power law is also influenced by mechanical prestress borne by the cytoskeleton, suggesting that cytoskeletal prestress determines the cell's viscoelasticity, but the biophysical origins of this behavior are largely unknown. We have recently developed a stochastic two-dimensional model of an elastically joined chain that links the power-law rheology to the prestress. Here we use a similar approach to study the creep response of a prestressed three-dimensional elastically jointed chain as a viscoelastic model of semiflexible polymers that comprise the prestressed cytoskeletal lattice. Using a Monte Carlo based algorithm, we show that numerical simulations of the chain's creep behavior closely correspond to the behavior observed experimentally in living cells. The power-law creep behavior results from a finite-speed propagation of free energy from the chain's end points toward the center of the chain in response to an externally applied stretching force. The property that links the power law to the prestress is the chain's stiffening with increasing prestress, which originates from entropic and enthalpic contributions. These results indicate that the essential features of cellular rheology can be explained by the viscoelastic behaviors of individual semiflexible polymers of the cytoskeleton.

  20. High-power UV-LED degradation: Continuous and cycled working condition influence

    Science.gov (United States)

    Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

    2015-09-01

    High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

  1. Resurrecting power law inflation in the light of Planck results

    International Nuclear Information System (INIS)

    Unnikrishnan, Sanil; Sahni, Varun

    2013-01-01

    It is well known that a canonical scalar field with an exponential potential can drive power law inflation (PLI). However, the tensor-to-scalar ratio in such models turns out to be larger than the stringent limit set by recent Planck results. We propose a new model of power law inflation for which the scalar spectra index, the tensor-to-scalar ratio and the non-gaussianity parameter f NL equil are in excellent agreement with Planck results. Inflation, in this model, is driven by a non-canonical scalar field with an inverse power law potential. The Lagrangian for our model is structurally similar to that of a canonical scalar field and has a power law form for the kinetic term. A simple extension of our model resolves the graceful exit problem which usually afflicts models of power law inflation

  2. Power laws for gravity and topography of Solar System bodies

    Science.gov (United States)

    Ermakov, A.; Park, R. S.; Bills, B. G.

    2017-12-01

    When a spacecraft visits a planetary body, it is useful to be able to predict its gravitational and topographic properties. This knowledge is important for determining the level of perturbations in spacecraft's motion as well as for planning the observation campaign. It has been known for the Earth that the power spectrum of gravity follows a power law, also known as the Kaula rule (Kaula, 1963; Rapp, 1989). A similar rule was derived for topography (Vening-Meinesz, 1951). The goal of this paper is to generalize the power law that can characterize the gravity and topography power spectra for bodies across a wide range of size. We have analyzed shape power spectra of the bodies that have either global shape and gravity field measured. These bodies span across five orders of magnitude in their radii and surface gravities and include terrestrial planets, icy moons and minor bodies. We have found that despite having different internal structure, composition and mechanical properties, the topography power spectrum of these bodies' shapes can be modeled with a similar power law rescaled by the surface gravity. Having empirically found a power law for topography, we can map it to a gravity power law. Special care should be taken for low-degree harmonic coefficients due to potential isostatic compensation. For minor bodies, uniform density can be assumed. The gravity coefficients are a linear function of the shape coefficients for close-to-spherical bodoes. In this case, the power law for gravity will be steeper than the power law of topography due to the factor (2n+1) in the gravity expansion (e.g. Eq. 10 in Wieczorek & Phillips, 1998). Higher powers of topography must be retained for irregularly shaped bodies, which breaks the linearity. Therefore, we propose the following procedure to derive an a priori constraint for gravity. First, a surface gravity needs to be determined assuming typical density for the relevant class of bodies. Second, the scaling coefficient of the

  3. On the structure and phase transitions of power-law Poissonian ensembles

    Science.gov (United States)

    Eliazar, Iddo; Oshanin, Gleb

    2012-10-01

    Power-law Poissonian ensembles are Poisson processes that are defined on the positive half-line, and that are governed by power-law intensities. Power-law Poissonian ensembles are stochastic objects of fundamental significance; they uniquely display an array of fractal features and they uniquely generate a span of important applications. In this paper we apply three different methods—oligarchic analysis, Lorenzian analysis and heterogeneity analysis—to explore power-law Poissonian ensembles. The amalgamation of these analyses, combined with the topology of power-law Poissonian ensembles, establishes a detailed and multi-faceted picture of the statistical structure and the statistical phase transitions of these elemental ensembles.

  4. The new law on radiation and nuclear power

    International Nuclear Information System (INIS)

    Niittylae, A.

    1990-01-01

    The Law on Nuclear Energy, which entered into force in 1988, controls the use of nuclear power. The new Law on Radiation is under consideration in the Parliament. The internationally approved main principles on radiation protection are the basis of the law. In the article, these principles and the contents of the law are described

  5. On the universality of power laws for tokamak plasma predictions

    Science.gov (United States)

    Garcia, J.; Cambon, D.; Contributors, JET

    2018-02-01

    Significant deviations from well established power laws for the thermal energy confinement time, obtained from extensive databases analysis as the IPB98(y,2), have been recently reported in dedicated power scans. In order to illuminate the adequacy, validity and universality of power laws as tools for predicting plasma performance, a simplified analysis has been carried out in the framework of a minimal modeling for heat transport which is, however, able to account for the interplay between turbulence and collinear effects with the input power known to play a role in experiments with significant deviations from such power laws. Whereas at low powers, the usual scaling laws are recovered with little influence of other plasma parameters, resulting in a robust power low exponent, at high power it is shown how the exponents obtained are extremely sensitive to the heating deposition, the q-profile or even the sampling or the number of points considered due to highly non-linear behavior of the heat transport. In particular circumstances, even a minimum of the thermal energy confinement time with the input power can be obtained, which means that the approach of the energy confinement time as a power law might be intrinsically invalid. Therefore plasma predictions with a power law approximation with a constant exponent obtained from a regression of a broad range of powers and other plasma parameters which can non-linearly affect and suppress heat transport, can lead to misleading results suggesting that this approach should be taken cautiously and its results continuously compared with modeling which can properly capture the underline physics, as gyrokinetic simulations.

  6. Kant on causal laws and powers.

    Science.gov (United States)

    Henschen, Tobias

    2014-12-01

    The aim of the paper is threefold. Its first aim is to defend Eric Watkins's claim that for Kant, a cause is not an event but a causal power: a power that is borne by a substance, and that, when active, brings about its effect, i.e. a change of the states of another substance, by generating a continuous flow of intermediate states of that substance. The second aim of the paper is to argue against Watkins that the Kantian concept of causal power is not the pre-critical concept of real ground but the category of causality, and that Kant holds with Hume that causal laws cannot be inferred non-inductively (that he accordingly has no intention to show in the Second analogy or elsewhere that events fall under causal laws). The third aim of the paper is to compare the Kantian position on causality with central tenets of contemporary powers ontology: it argues that unlike the variants endorsed by contemporary powers theorists, the Kantian variants of these tenets are resistant to objections that neo-Humeans raise to these tenets.

  7. The origin of power-law distributions in self-organized criticality

    International Nuclear Information System (INIS)

    Yang, C B

    2004-01-01

    The origin of power-law distributions in self-organized criticality is investigated by treating the variation of the number of active sites in the system as a stochastic process. An avalanche is then regarded as a first-return random-walk process in a one-dimensional lattice. Power-law distributions of the lifetime and spatial size are found when the random walk is unbiased with equal probability to move in opposite directions. This shows that power-law distributions in self-organized criticality may be caused by the balance of competitive interactions. At the mean time, the mean spatial size for avalanches with the same lifetime is found to increase in a power law with the lifetime. (letter to the editor)

  8. Econophysical anchoring of unimodal power-law distributions

    International Nuclear Information System (INIS)

    Eliazar, Iddo I; Cohen, Morrel H

    2013-01-01

    The sciences are abundant with size distributions whose densities have a unimodal shape and power-law tails both at zero and at infinity. The quintessential examples of such unimodal and power-law (UPL) distributions are the sizes of income and wealth in human societies. While the tails of UPL distributions are precisely quantified by their corresponding power-law exponents, their bulks are only qualitatively characterized as unimodal. Consequently, different statistical models of UPL distributions exist, the most popular considering lognormal bulks. In this paper we present a general econophysical framework for UPL distributions termed ‘the anchoring method’. This method: (i) universally approximates UPL distributions via three ‘anchors’ set at zero, at infinity, and at an intermediate point between zero and infinity (e.g. the mode); (ii) is highly versatile and broadly applicable; (iii) encompasses the existing statistical models of UPL distributions as special cases; (iv) facilitates the introduction of new statistical models of UPL distributions and (v) yields a socioeconophysical analysis of UPL distributions. (paper)

  9. Models of fragmentation with composite power laws

    Science.gov (United States)

    Tavassoli, Z.; Rodgers, G. J.

    1999-06-01

    Some models for binary fragmentation are introduced in which a time dependent transition size produces two regions of fragment sizes above and below the transition size. In the first model we assume a fixed rate of fragmentation for the largest fragment and two different rates of fragmentation in the two regions of sizes above and below the transition size. The model is solved exactly in the long time limit to reveal stable time-invariant solutions for the fragment size and mass distributions. These solutions exhibit composite power law behaviours; power laws with two different exponents for fragments in smaller and larger regions. A special case of the model with no fragmentation in the smaller size region is also examined. Another model is also introduced which have three regions of fragment sizes with different rates of fragmentation. The similarities between the stable distributions in our models and composite power law distributions from experimental work on shock fragmentation of long thin glass rods and thick clay plates are discussed.

  10. Power-law and intermediate inflationary models in f(T)-gravity

    Energy Technology Data Exchange (ETDEWEB)

    Rezazadeh, K. [Department of Physics, University of Kurdistan,Pasdaran St., Sanandaj (Iran, Islamic Republic of); Abdolmaleki, A. [Research Institute for Astronomy Astrophysics of Maragha (RIAAM),P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Karami, K. [Department of Physics, University of Kurdistan,Pasdaran St., Sanandaj (Iran, Islamic Republic of)

    2016-01-21

    We study inflation in the framework of f(T)-gravity in the presence of a canonical scalar field. After reviewing the basic equations governing the background cosmology in f(T)-gravity, we turn to study the cosmological perturbations and obtain the evolutionary equations for the scalar and tensor perturbations. Solving those equations, we find the power spectra for the scalar and tensor perturbations. Then, we consider a power-law f(T) function and investigate the inflationary models with the power-law and intermediate scale factors. We see that in contrast with the standard inflationary scenario based on the Einstein gravity, the power-law and intermediate inflationary models in f(T)-gravity can be compatible with the observational results of Planck 2015 at 68% CL. We find that in our f(T) setting, the potentials responsible for the both power-law and intermediate inflationary models have the power-law form V(ϕ)∝ϕ{sup m} but the power m is different for them. Therefore, we can refine some of power-law inflationary potentials in the framework of f(T)-gravity while they are disfavored by the observational data in the standard inflationary scenario. Interestingly enough, is that the self-interacting quartic potential V(ϕ)∝ϕ{sup 4} which has special reheating properties, can be consistent with the Planck 2015 data in our f(T) scenario while it is ruled out in the standard inflationary scenario.

  11. Power-law and intermediate inflationary models in f(T)-gravity

    International Nuclear Information System (INIS)

    Rezazadeh, K.; Abdolmaleki, A.; Karami, K.

    2016-01-01

    We study inflation in the framework of f(T)-gravity in the presence of a canonical scalar field. After reviewing the basic equations governing the background cosmology in f(T)-gravity, we turn to study the cosmological perturbations and obtain the evolutionary equations for the scalar and tensor perturbations. Solving those equations, we find the power spectra for the scalar and tensor perturbations. Then, we consider a power-law f(T) function and investigate the inflationary models with the power-law and intermediate scale factors. We see that in contrast with the standard inflationary scenario based on the Einstein gravity, the power-law and intermediate inflationary models in f(T)-gravity can be compatible with the observational results of Planck 2015 at 68% CL. We find that in our f(T) setting, the potentials responsible for the both power-law and intermediate inflationary models have the power-law form V(ϕ)∝ϕ m but the power m is different for them. Therefore, we can refine some of power-law inflationary potentials in the framework of f(T)-gravity while they are disfavored by the observational data in the standard inflationary scenario. Interestingly enough, is that the self-interacting quartic potential V(ϕ)∝ϕ 4 which has special reheating properties, can be consistent with the Planck 2015 data in our f(T) scenario while it is ruled out in the standard inflationary scenario.

  12. Nonlinear and linear wave equations for propagation in media with frequency power law losses

    Science.gov (United States)

    Szabo, Thomas L.

    2003-10-01

    The Burgers, KZK, and Westervelt wave equations used for simulating wave propagation in nonlinear media are based on absorption that has a quadratic dependence on frequency. Unfortunately, most lossy media, such as tissue, follow a more general frequency power law. The authors first research involved measurements of loss and dispersion associated with a modification to Blackstock's solution to the linear thermoviscous wave equation [J. Acoust. Soc. Am. 41, 1312 (1967)]. A second paper by Blackstock [J. Acoust. Soc. Am. 77, 2050 (1985)] showed the loss term in the Burgers equation for plane waves could be modified for other known instances of loss. The authors' work eventually led to comprehensive time-domain convolutional operators that accounted for both dispersion and general frequency power law absorption [Szabo, J. Acoust. Soc. Am. 96, 491 (1994)]. Versions of appropriate loss terms were developed to extend the standard three nonlinear wave equations to these more general losses. Extensive experimental data has verified the predicted phase velocity dispersion for different power exponents for the linear case. Other groups are now working on methods suitable for solving wave equations numerically for these types of loss directly in the time domain for both linear and nonlinear media.

  13. Power-law and runaway growth in conserved aggregation systems

    International Nuclear Information System (INIS)

    Yamamoto, Hiroshi; Ohtsuki, Toshiya; Fujihara, Akihiro; Tanimoto, Satoshi

    2006-01-01

    The z-transform technique is used to analyze the Smoluchowski coagulation equation for conserved aggregation systems. A universal power law with the exponent -5/2 appears when a total 'mass' has a certain critical value. Below the threshold, ordinary scaling relations hold and the system exhibits a behavior like usual critical phenomena. Above the threshold, in contrast, the excess amount of mass coagulates into a runaway member, and remaining members follow the power law. Here the runaway growth coexists with the power law. It is argued that these behaviors are observed universally in conserved aggregation processes

  14. Financial power laws: Empirical evidence, models, and mechanisms

    International Nuclear Information System (INIS)

    Lux, Thomas; Alfarano, Simone

    2016-01-01

    Financial markets (share markets, foreign exchange markets and others) are all characterized by a number of universal power laws. The most prominent example is the ubiquitous finding of a robust, approximately cubic power law characterizing the distribution of large returns. A similarly robust feature is long-range dependence in volatility (i.e., hyperbolic decline of its autocorrelation function). The recent literature adds temporal scaling of trading volume and multi-scaling of higher moments of returns. Increasing awareness of these properties has recently spurred attempts at theoretical explanations of the emergence of these key characteristics form the market process. In principle, different types of dynamic processes could be responsible for these power-laws. Examples to be found in the economics literature include multiplicative stochastic processes as well as dynamic processes with multiple equilibria. Though both types of dynamics are characterized by intermittent behavior which occasionally generates large bursts of activity, they can be based on fundamentally different perceptions of the trading process. The present paper reviews both the analytical background of the power laws emerging from the above data generating mechanisms as well as pertinent models proposed in the economics literature.

  15. Testing power-law cross-correlations: Rescaled covariance test

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2013-01-01

    Roč. 86, č. 10 (2013), 418-1-418-15 ISSN 1434-6028 R&D Projects: GA ČR GA402/09/0965 Institutional support: RVO:67985556 Keywords : power-law cross-correlations * testing * long-term memory Subject RIV: AH - Economics Impact factor: 1.463, year: 2013 http://library.utia.cas.cz/separaty/2013/E/kristoufek-testing power-law cross-correlations rescaled covariance test.pdf

  16. Evapotranspiration Power Law in Self-Organized and Human-Managed Ecosystems

    Science.gov (United States)

    Zeng, R.; Cai, X.

    2017-12-01

    Natural systems display a profound degree of self-organization, often apparent even to the untrained eye. However, in this age of increased coupling among human and natural systems, it is unclear to what degree natural organization principles continue to govern human-managed landscapes. Here we present an emerging characteristic of terrestrial evapotranspiration (ET), one of the key components of the water cycle and energy budget, adhered to by both naturally organized and intensively managed landscapes. We find that ET variance and ET mean for ecosystems throughout the world with diverse climate conditions, vegetation structures, and land covers and land uses organize themselves according to a specific power law curve. From multi-source observations, the ET power law curve stands true through varying spatial scales, from field to region. Moreover, a phenomenon of similar ecosystems gravitating toward particular segments of the power law curve, suggests that the feature of self-optimization of ecosystems establishes the ET power law together with climatic conditions. Perhaps surprisingly, we find that landscapes persistently follow the power law curve even upon human-induced transition from rain-fed to irrigated agriculture in the American High Plains and from wetland to agricultural land in American Midwest. As such, the ET power law can be an informative tool for predicting consequences of anthropogenic disturbances to the hydrologic cycle and understanding constraints to sustainable land use.

  17. The Integration of Virtual Public-Private Partnerships into Local Law Enforcement to Achieve Enhanced Intelligence-Led Policing

    National Research Council Canada - National Science Library

    Simeone, Jr, Matthew J

    2007-01-01

    In light of the recent emergence of fusion centers and centralized intelligence units, and the move to develop intelligence capacity within local law enforcement agencies in the United States, intelligence-led policing (ILP...

  18. Power-law and exponential rank distributions: A panoramic Gibbsian perspective

    International Nuclear Information System (INIS)

    Eliazar, Iddo

    2015-01-01

    Rank distributions are collections of positive sizes ordered either increasingly or decreasingly. Many decreasing rank distributions, formed by the collective collaboration of human actions, follow an inverse power-law relation between ranks and sizes. This remarkable empirical fact is termed Zipf’s law, and one of its quintessential manifestations is the demography of human settlements — which exhibits a harmonic relation between ranks and sizes. In this paper we present a comprehensive statistical-physics analysis of rank distributions, establish that power-law and exponential rank distributions stand out as optimal in various entropy-based senses, and unveil the special role of the harmonic relation between ranks and sizes. Our results extend the contemporary entropy-maximization view of Zipf’s law to a broader, panoramic, Gibbsian perspective of increasing and decreasing power-law and exponential rank distributions — of which Zipf’s law is one out of four pillars

  19. Power-law and exponential rank distributions: A panoramic Gibbsian perspective

    Energy Technology Data Exchange (ETDEWEB)

    Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il

    2015-04-15

    Rank distributions are collections of positive sizes ordered either increasingly or decreasingly. Many decreasing rank distributions, formed by the collective collaboration of human actions, follow an inverse power-law relation between ranks and sizes. This remarkable empirical fact is termed Zipf’s law, and one of its quintessential manifestations is the demography of human settlements — which exhibits a harmonic relation between ranks and sizes. In this paper we present a comprehensive statistical-physics analysis of rank distributions, establish that power-law and exponential rank distributions stand out as optimal in various entropy-based senses, and unveil the special role of the harmonic relation between ranks and sizes. Our results extend the contemporary entropy-maximization view of Zipf’s law to a broader, panoramic, Gibbsian perspective of increasing and decreasing power-law and exponential rank distributions — of which Zipf’s law is one out of four pillars.

  20. Constraints on cosmological parameters in power-law cosmology

    International Nuclear Information System (INIS)

    Rani, Sarita; Singh, J.K.; Altaibayeva, A.; Myrzakulov, R.; Shahalam, M.

    2015-01-01

    In this paper, we examine observational constraints on the power law cosmology; essentially dependent on two parameters H 0 (Hubble constant) and q (deceleration parameter). We investigate the constraints on these parameters using the latest 28 points of H(z) data and 580 points of Union2.1 compilation data and, compare the results with the results of ΛCDM . We also forecast constraints using a simulated data set for the future JDEM, supernovae survey. Our studies give better insight into power law cosmology than the earlier done analysis by Kumar [arXiv:1109.6924] indicating it tuning well with Union2.1 compilation data but not with H(z) data. However, the constraints obtained on and i.e. H 0 average and q average using the simulated data set for the future JDEM, supernovae survey are found to be inconsistent with the values obtained from the H(z) and Union2.1 compilation data. We also perform the statefinder analysis and find that the power-law cosmological models approach the standard ΛCDM model as q → −1. Finally, we observe that although the power law cosmology explains several prominent features of evolution of the Universe, it fails in details

  1. LED power efficiency of biomass, fatty acid, and carotenoid production in Nannochloropsis microalgae.

    Science.gov (United States)

    Ma, Ruijuan; Thomas-Hall, Skye R; Chua, Elvis T; Eltanahy, Eladl; Netzel, Michael E; Netzel, Gabriele; Lu, Yinghua; Schenk, Peer M

    2018-03-01

    The microalga Nannochloropsis produces high-value omega-3-rich fatty acids and carotenoids. In this study the effects of light intensity and wavelength on biomass, fatty acid, and carotenoid production with respect to light output efficiency were investigated. Similar biomass and fatty acid yields were obtained at high light intensity (150 μmol m -2  s -1 ) LEDs on day 7 and low light intensity (50 μmol m -2  s -1 ) LEDs on day 11 during cultivation, but the power efficiencies of biomass and fatty acid (specifically eicosapentaenoic acid) production were higher for low light intensity. Interestingly, low light intensity enhanced both, carotenoid power efficiency of carotenoid biosynthesis and yield. White LEDs were neither advantageous for biomass and fatty acid yields, nor the power efficiency of biomass, fatty acid, and carotenoid production. Noticeably, red LED resulted in the highest biomass and fatty acid power efficiency, suggesting that LEDs can be fine-tuned to grow Nannochloropsis algae more energy-efficiently. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Do wealth distributions follow power laws? Evidence from ‘rich lists’

    Science.gov (United States)

    Brzezinski, Michal

    2014-07-01

    We use data on the wealth of the richest persons taken from the 'rich lists' provided by business magazines like Forbes to verify if the upper tails of wealth distributions follow, as often claimed, a power-law behaviour. The data sets used cover the world's richest persons over 1996-2012, the richest Americans over 1988-2012, the richest Chinese over 2006-2012, and the richest Russians over 2004-2011. Using a recently introduced comprehensive empirical methodology for detecting power laws, which allows for testing the goodness of fit as well as for comparing the power-law model with rival distributions, we find that a power-law model is consistent with data only in 35% of the analysed data sets. Moreover, even if wealth data are consistent with the power-law model, they are usually also consistent with some rivals like the log-normal or stretched exponential distributions.

  3. The p-sphere and the geometric substratum of power-law probability distributions

    International Nuclear Information System (INIS)

    Vignat, C.; Plastino, A.

    2005-01-01

    Links between power law probability distributions and marginal distributions of uniform laws on p-spheres in R n show that a mathematical derivation of the Boltzmann-Gibbs distribution necessarily passes through power law ones. Results are also given that link parameters p and n to the value of the non-extensivity parameter q that characterizes these power laws in the context of non-extensive statistics

  4. Unobserved heterogeneity in the power law nonhomogeneous Poisson process

    International Nuclear Information System (INIS)

    Asfaw, Zeytu Gashaw; Lindqvist, Bo Henry

    2015-01-01

    A study of possible consequences of heterogeneity in the failure intensity of repairable systems is presented. The basic model studied is the nonhomogeneous Poisson process with power law intensity function. When several similar systems are under observation, the assumption that the corresponding processes are independent and identically distributed is often questionable. In practice there may be an unobserved heterogeneity among the systems. The heterogeneity is modeled by introduction of unobserved gamma distributed frailties. The relevant likelihood function is derived, and maximum likelihood estimation is illustrated. In a simulation study we then compare results when using a power law model without taking into account heterogeneity, with the corresponding results obtained when the heterogeneity is accounted for. A motivating data example is also given. - Highlights: • Consequences of overlooking heterogeneity in similar repairable systems are studied. • Likelihood functions are established for power law NHPP w/ and w/o heterogeneity. • ML estimators for parameters of power law NHPP with heterogeneity are derived. • A simulation study shows the effects of heterogeneity and its ignorance in models

  5. Power laws from linear neuronal cable theory

    DEFF Research Database (Denmark)

    Pettersen, Klas H; Lindén, Henrik Anders; Tetzlaff, Tom

    2014-01-01

    suggested to be at the root of this phenomenon, we here demonstrate a possible origin of such power laws in the biophysical properties of single neurons described by the standard cable equation. Taking advantage of the analytical tractability of the so called ball and stick neuron model, we derive general...... are homogeneously distributed across the neural membranes and themselves exhibit pink ([Formula: see text]) noise distributions. While the PSD noise spectra at low frequencies may be dominated by synaptic noise, our findings suggest that the high-frequency power laws may originate in noise from intrinsic ion...

  6. The distance-decay function of geographical gravity model: Power law or exponential law?

    International Nuclear Information System (INIS)

    Chen, Yanguang

    2015-01-01

    Highlights: •The distance-decay exponent of the gravity model is a fractal dimension. •Entropy maximization accounts for the gravity model based on power law decay. •Allometric scaling relations relate gravity models with spatial interaction models. •The four-parameter gravity models have dual mathematical expressions. •The inverse power law is the most probable distance-decay function. -- Abstract: The distance-decay function of the geographical gravity model is originally an inverse power law, which suggests a scaling process in spatial interaction. However, the distance exponent of the model cannot be reasonably explained with the ideas from Euclidean geometry. This results in a dimension dilemma in geographical analysis. Consequently, a negative exponential function was used to replace the inverse power function to serve for a distance-decay function. But a new puzzle arose that the exponential-based gravity model goes against the first law of geography. This paper is devoted for solving these kinds of problems by mathematical reasoning and empirical analysis. New findings are as follows. First, the distance exponent of the gravity model is demonstrated to be a fractal dimension using the geometric measure relation. Second, the similarities and differences between the gravity models and spatial interaction models are revealed using allometric relations. Third, a four-parameter gravity model possesses a symmetrical expression, and we need dual gravity models to describe spatial flows. The observational data of China's cities and regions (29 elements indicative of 841 data points) in 2010 are employed to verify the theoretical inferences. A conclusion can be reached that the geographical gravity model based on power-law decay is more suitable for analyzing large, complex, and scale-free regional and urban systems. This study lends further support to the suggestion that the underlying rationale of fractal structure is entropy maximization. Moreover

  7. Integrated Automotive High-Power LED-Lighting Systems in 3D-MID Technology

    NARCIS (Netherlands)

    Thomas, W.

    2014-01-01

    The growing energy consumption of lighting as well as rising luminous efficacies and -fluxes of high-power Light Emitting Diodes (LEDs) have contributed to the widespread use of LEDs in modern lighting systems. One of the most prominent users of the LED-technology is automotive (exterior) lighting.

  8. Exponential and power laws in public procurement markets

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Skuhrovec, J.

    2012-01-01

    Roč. 99, č. 2 (2012), 28005-1-28005-6 ISSN 0295-5075 R&D Projects: GA ČR GA402/09/0965 Grant - others:GA UK(CZ) 118310; SVV(CZ) 265 504; GA TA ČR(CZ) TD010133 Institutional support: RVO:67985556 Keywords : Public procurement * Scaling * Power law Subject RIV: AH - Economics Impact factor: 2.260, year: 2012 http://library.utia.cas.cz/separaty/2012/E/kristoufek-exponential and power laws in public procurement markets.pdf

  9. Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

    KAUST Repository

    Cheng, W.; Samtaney, Ravi

    2014-01-01

    The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can

  10. Stretched exponentials and power laws in granular avalanching

    Science.gov (United States)

    Head, D. A.; Rodgers, G. J.

    1999-02-01

    We introduce a model for granular surface flow which exhibits both stretched exponential and power law avalanching over its parameter range. Two modes of transport are incorporated, a rolling layer consisting of individual particles and the overdamped, sliding motion of particle clusters. The crossover in behaviour observed in experiments on piles of rice is attributed to a change in the dominant mode of transport. We predict that power law avalanching will be observed whenever surface flow is dominated by clustered motion.

  11. Power-law thermal model for blackbody sources

    International Nuclear Information System (INIS)

    Del Grande, N.K.

    1979-01-01

    The spectral radiant emittance W/sub E/ from a blackbody at a temperature kT for photons at energies E above the spectral peak (2.82144 kT) varies as (kT)/sup E/kT/. This power-law temperature dependence, an approximation of Planck's radiation law, may have applications for measuring the emissivity of sources emitting in the soft x-ray region

  12. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  13. Mixed-correlated ARFIMA processes for power-law cross-correlations

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2013-01-01

    Roč. 392, č. 24 (2013), s. 6484-6493 ISSN 0378-4371 R&D Projects: GA ČR GA402/09/0965 Institutional support: RVO:67985556 Keywords : power-law cross-correlations * long - term memory * econophysics Subject RIV: AH - Economics Impact factor: 1.722, year: 2013 http://library.utia.cas.cz/separaty/2013/E/kristoufek-mixed-correlated arfima processes for power-law cross-correlations.pdf

  14. Mobile user forecast and power-law acceleration invariance of scale-free networks

    International Nuclear Information System (INIS)

    Guo Jin-Li; Guo Zhao-Hua; Liu Xue-Jiao

    2011-01-01

    This paper studies and predicts the number growth of China's mobile users by using the power-law regression. We find that the number growth of the mobile users follows a power law. Motivated by the data on the evolution of the mobile users, we consider scenarios of self-organization of accelerating growth networks into scale-free structures and propose a directed network model, in which the nodes grow following a power-law acceleration. The expressions for the transient and the stationary average degree distributions are obtained by using the Poisson process. This result shows that the model generates appropriate power-law connectivity distributions. Therefore, we find a power-law acceleration invariance of the scale-free networks. The numerical simulations of the models agree with the analytical results well. (interdisciplinary physics and related areas of science and technology)

  15. Power-law ansatz in complex systems: Excessive loss of information

    Science.gov (United States)

    Tsai, Sun-Ting; Chang, Chin-De; Chang, Ching-Hao; Tsai, Meng-Xue; Hsu, Nan-Jung; Hong, Tzay-Ming

    2015-12-01

    The ubiquity of power-law relations in empirical data displays physicists' love of simple laws and uncovering common causes among seemingly unrelated phenomena. However, many reported power laws lack statistical support and mechanistic backings, not to mention discrepancies with real data are often explained away as corrections due to finite size or other variables. We propose a simple experiment and rigorous statistical procedures to look into these issues. Making use of the fact that the occurrence rate and pulse intensity of crumple sound obey a power law with an exponent that varies with material, we simulate a complex system with two driving mechanisms by crumpling two different sheets together. The probability function of the crumple sound is found to transit from two power-law terms to a bona fide power law as compaction increases. In addition to showing the vicinity of these two distributions in the phase space, this observation nicely demonstrates the effect of interactions to bring about a subtle change in macroscopic behavior and more information may be retrieved if the data are subject to sorting. Our analyses are based on the Akaike information criterion that is a direct measurement of information loss and emphasizes the need to strike a balance between model simplicity and goodness of fit. As a show of force, the Akaike information criterion also found the Gutenberg-Richter law for earthquakes and the scale-free model for a brain functional network, a two-dimensional sandpile, and solar flare intensity to suffer an excessive loss of information. They resemble more the crumpled-together ball at low compactions in that there appear to be two driving mechanisms that take turns occurring.

  16. Power-law ansatz in complex systems: Excessive loss of information.

    Science.gov (United States)

    Tsai, Sun-Ting; Chang, Chin-De; Chang, Ching-Hao; Tsai, Meng-Xue; Hsu, Nan-Jung; Hong, Tzay-Ming

    2015-12-01

    The ubiquity of power-law relations in empirical data displays physicists' love of simple laws and uncovering common causes among seemingly unrelated phenomena. However, many reported power laws lack statistical support and mechanistic backings, not to mention discrepancies with real data are often explained away as corrections due to finite size or other variables. We propose a simple experiment and rigorous statistical procedures to look into these issues. Making use of the fact that the occurrence rate and pulse intensity of crumple sound obey a power law with an exponent that varies with material, we simulate a complex system with two driving mechanisms by crumpling two different sheets together. The probability function of the crumple sound is found to transit from two power-law terms to a bona fide power law as compaction increases. In addition to showing the vicinity of these two distributions in the phase space, this observation nicely demonstrates the effect of interactions to bring about a subtle change in macroscopic behavior and more information may be retrieved if the data are subject to sorting. Our analyses are based on the Akaike information criterion that is a direct measurement of information loss and emphasizes the need to strike a balance between model simplicity and goodness of fit. As a show of force, the Akaike information criterion also found the Gutenberg-Richter law for earthquakes and the scale-free model for a brain functional network, a two-dimensional sandpile, and solar flare intensity to suffer an excessive loss of information. They resemble more the crumpled-together ball at low compactions in that there appear to be two driving mechanisms that take turns occurring.

  17. The Normalising Power of Marriage Law: An Irish Genealogy, 1945 – 2010

    OpenAIRE

    McGowan, Deirdre

    2015-01-01

    Marriage law is often conceptualised as an instrument of power that illegitimately imposes the will of the State on its citizens. Paradoxically, marriage law is also offered as a route to liberation. In this thesis, I question the efficacy of this type of analysis by investigating the actual power effects of marriage law. Using Michel Foucault’s concepts of bio-power and government, and his genealogical approach to history, I identify the role played by marriage law in governing the social do...

  18. Stable power laws in variable economies; Lotka-Volterra implies Pareto-Zipf

    Science.gov (United States)

    Solomon, S.; Richmond, P.

    2002-05-01

    In recent years we have found that logistic systems of the Generalized Lotka-Volterra type (GLV) describing statistical systems of auto-catalytic elements posses power law distributions of the Pareto-Zipf type. In particular, when applied to economic systems, GLV leads to power laws in the relative individual wealth distribution and in market returns. These power laws and their exponent α are invariant to arbitrary variations in the total wealth of the system and to other endogenously and exogenously induced variations.

  19. 29 CFR 102.35 - Duties and powers of administrative law judges; stipulations of cases to administrative law...

    Science.gov (United States)

    2010-07-01

    ..., the judge (or the Board) will decide the case or make other disposition of it. (10) To make and file... 29 Labor 2 2010-07-01 2010-07-01 false Duties and powers of administrative law judges; stipulations of cases to administrative law judges or to the Board; assignment and powers of settlement judges...

  20. Power-Law Statistics of Driven Reconnection in the Magnetically Closed Corona

    Science.gov (United States)

    Klimchuk, J. A.; DeVore, C. R.; Knizhnik, K. J.; Uritskiy, V. M.

    2018-01-01

    Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.

  1. Power-law Statistics of Driven Reconnection in the Magnetically Closed Corona

    Science.gov (United States)

    Knizhnik, K. J.; Uritsky, V. M.; Klimchuk, J. A.; DeVore, C. R.

    2018-01-01

    Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.

  2. Seepage Characteristics Study on Power-Law Fluid in Fractal Porous Media

    Directory of Open Access Journals (Sweden)

    Meijuan Yun

    2014-01-01

    Full Text Available We present fractal models for the flow rate, velocity, effective viscosity, apparent viscosity, and effective permeability for power-law fluid based on the fractal properties of porous media. The proposed expressions realize the quantitative description to the relation between the properties of the power-law fluid and the parameters of the microstructure of the porous media. The model predictions are compared with related data and good agreement between them is found. The analytical expressions will contribute to the revealing of physical principles for the power-law fluid flow in porous media.

  3. Power Laws in Stochastic Processes for Social Phenomena: An Introductory Review

    Science.gov (United States)

    Kumamoto, Shin-Ichiro; Kamihigashi, Takashi

    2018-03-01

    Many phenomena with power laws have been observed in various fields of the natural and social sciences, and these power laws are often interpreted as the macro behaviors of systems that consist of micro units. In this paper, we review some basic mathematical mechanisms that are known to generate power laws. In particular, we focus on stochastic processes including the Yule process and the Simon process as well as some recent models. The main purpose of this paper is to explain the mathematical details of their mechanisms in a self-contained manner.

  4. Power-law citation distributions are not scale-free.

    Science.gov (United States)

    Golosovsky, Michael

    2017-09-01

    We analyze time evolution of statistical distributions of citations to scientific papers published in the same year. While these distributions seem to follow the power-law dependence we find that they are nonstationary and the exponent of the power-law fit decreases with time and does not come to saturation. We attribute the nonstationarity of citation distributions to different longevity of the low-cited and highly cited papers. By measuring citation trajectories of papers we found that citation careers of the low-cited papers come to saturation after 10-15 years while those of the highly cited papers continue to increase indefinitely: The papers that exceed some citation threshold become runaways. Thus, we show that although citation distribution can look as a power-law dependence, it is not scale free and there is a hidden dynamic scale associated with the onset of runaways. We compare our measurements to our recently developed model of citation dynamics based on copying-redirection-triadic closure and find explanations to our empirical observations.

  5. Uniformity measure for power-law mass spectrum in nuclear fragmentation

    International Nuclear Information System (INIS)

    Wislicki, W.

    1992-11-01

    Description is given in terms of the Renyi entropy and the uniformity for the canonical ensemble, the grand canonical ensemble and the power-law probability measures. The study is presented of the power-law spectra of cluster masses observed in nuclear interactions in the vicinity of the liquid-gas transition point. 6 figs., 1 tab., 15 refs. (author)

  6. Observational constraints on phantom power-law cosmology

    International Nuclear Information System (INIS)

    Kaeonikhom, Chakkrit; Gumjudpai, Burin; Saridakis, Emmanuel N.

    2011-01-01

    We investigate phantom cosmology in which the scale factor is a power law, and we use cosmological observations from Cosmic Microwave Background (CMB), Baryon Acoustic Oscillations (BAO) and observational Hubble data, in order to impose complete constraints on the model parameters. We find that the power-law exponent is β∼-6.51 -0.25 +0.24 , while the Big Rip is realized at t s ∼104.5 -2.0 +1.9 Gyr, in 1σ confidence level. Providing late-time asymptotic expressions, we find that the dark-energy equation-of-state parameter at the Big Rip remains finite and equal to w DE ∼-1.153, with the dark-energy density and pressure diverging. Finally, we reconstruct the phantom potential.

  7. Dynamic intersectoral models with power-law memory

    Science.gov (United States)

    Tarasova, Valentina V.; Tarasov, Vasily E.

    2018-01-01

    Intersectoral dynamic models with power-law memory are proposed. The equations of open and closed intersectoral models, in which the memory effects are described by the Caputo derivatives of non-integer orders, are derived. We suggest solutions of these equations, which have the form of linear combinations of the Mittag-Leffler functions and which are characterized by different effective growth rates. Examples of intersectoral dynamics with power-law memory are suggested for two sectoral cases. We formulate two principles of intersectoral dynamics with memory: the principle of changing of technological growth rates and the principle of domination change. It has been shown that in the input-output economic dynamics the effects of fading memory can change the economic growth rate and dominant behavior of economic sectors.

  8. Variational principle for the Pareto power law.

    Science.gov (United States)

    Chakraborti, Anirban; Patriarca, Marco

    2009-11-27

    A mechanism is proposed for the appearance of power-law distributions in various complex systems. It is shown that in a conservative mechanical system composed of subsystems with different numbers of degrees of freedom a robust power-law tail can appear in the equilibrium distribution of energy as a result of certain superpositions of the canonical equilibrium energy densities of the subsystems. The derivation only uses a variational principle based on the Boltzmann entropy, without assumptions outside the framework of canonical equilibrium statistical mechanics. Two examples are discussed, free diffusion on a complex network and a kinetic model of wealth exchange. The mechanism is illustrated in the general case through an exactly solvable mechanical model of a dimensionally heterogeneous system.

  9. Influence of dome phosphor particle concentration on mid-power LED thermal resistance

    NARCIS (Netherlands)

    Alexeev, A.; Martin, G.; Hildenbrand, V.D.; Bosschaart, K.J.

    2016-01-01

    The modern white mid-power LEDs usually contain phosphor particles encapsulated in silicone dome material. The particles convert the blue light emitted from the epitaxial layer and play significant role in thermal processes of LED packages. In this paper the influence of the phosphor particles

  10. Exploring the effect of power law social popularity on language evolution.

    Science.gov (United States)

    Gong, Tao; Shuai, Lan

    2014-01-01

    We evaluate the effect of a power-law-distributed social popularity on the origin and change of language, based on three artificial life models meticulously tracing the evolution of linguistic conventions including lexical items, categories, and simple syntax. A cross-model analysis reveals an optimal social popularity, in which the λ value of the power law distribution is around 1.0. Under this scaling, linguistic conventions can efficiently emerge and widely diffuse among individuals, thus maintaining a useful level of mutual understandability even in a big population. From an evolutionary perspective, we regard this social optimality as a tradeoff among social scaling, mutual understandability, and population growth. Empirical evidence confirms that such optimal power laws exist in many large-scale social systems that are constructed primarily via language-related interactions. This study contributes to the empirical explorations and theoretical discussions of the evolutionary relations between ubiquitous power laws in social systems and relevant individual behaviors.

  11. Simple model for the power-law blinking of single semiconductor nanocrystals

    NARCIS (Netherlands)

    Verberk, Rogier; Oijen, Antoine M. van; Orrit, Michel

    2002-01-01

    We assign the blinking of nanocrystals to electron tunneling towards a uniform spatial distribution of traps. This naturally explains the power-law distribution of off times, and the power-law correlation function we measured on uncapped CdS dots. Capped dots, on the other hand, present extended on

  12. Regulatory Powers in Public Procurement Law of Peruvian Administrative Agencies

    Directory of Open Access Journals (Sweden)

    Juan Carlos Morón Urbina

    2017-12-01

    Full Text Available Peruvian law has explicitly recognized regulatory powers to administrative agencies, which allows them to have a preponderant role in the production of rules in public procurement. Although these delegations of legislative authority are positively defined, distortions in the system of legal sources arise when agencies exceed delegated powers or when measures issued by administrative entities are mistaken for regulations. This paper aims to identify regulatory powers of Peruvian administrative agencies, as well as the regulatory measures they issue, and their relation with other sources of law.

  13. A high-performance stand-alone solar PV power system for LED lighting

    KAUST Repository

    Huang, B. J.; Hsu, P. C.; Wu, M. S.; Chen, K.Y.

    2010-01-01

    The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system

  14. Development of constant-power driving control for light-emitting-diode (LED) luminaire

    KAUST Repository

    Huang, Bin-Juine; Chen, Chun-Wei; Ong, Chin-Dian; Du, Bo-Han; Hsu, Po-Chien

    2013-01-01

    changes from 0 to 40 °C, the LED illumination varies slightly (-1.7%) for constant-power driving, as compared to that of constant-current driving (-12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing

  15. Transport coefficients in Lorentz plasmas with the power-law kappa-distribution

    International Nuclear Information System (INIS)

    Jiulin, Du

    2013-01-01

    Transport coefficients in Lorentz plasma with the power-law κ-distribution are studied by means of using the transport equation and macroscopic laws of Lorentz plasma without magnetic field. Expressions of electric conductivity, thermoelectric coefficient, and thermal conductivity for the power-law κ-distribution are accurately derived. It is shown that these transport coefficients are significantly modified by the κ-parameter, and in the limit of the parameter κ→∞ they are reduced to the standard forms for a Maxwellian distribution

  16. Power law scaling in synchronization of brain signals depends on cognitive load

    Directory of Open Access Journals (Sweden)

    Jose Luis ePerez Velazquez

    2014-05-01

    Full Text Available As it has several features that optimize information processing, it has been proposed that criticality governs the dynamics of nervous system activity. Indications of such dynamics have been reported for a variety of in vitro and in vivo recordings, ranging from in vitro slice electrophysiology to human functional magnetic resonance imaging. However, there still remains considerable debate as to whether the brain actually operates close to criticality or in another governing state such as stochastic or oscillatory dynamics. A tool used to investigate the criticality of nervous system data is the inspection of power-law distributions. Although the findings are controversial, such power-law scaling has been found in different types of recordings. Here, we studied whether there is a power law scaling in the distribution of the phase synchronization derived from magnetoencephalographic recordings during executive function tasks performed by children with and without autism. Characterizing the brain dynamics that is different between autistic and non-autistic individuals is important in order to find differences that could either aid diagnosis or provide insights as to possible therapeutic interventions in autism. We report in this study that power law scaling in the distributions of a phase synchrony index is not very common and its frequency of occurrence is similar in the control and the autism group. In addition, power law scaling tends to diminish with increased cognitive load (difficulty or engagement in the task. There were indications of changes in the probability distribution functions for the phase synchrony that were associated with a transition from power law scaling to lack of power law (or vice versa, which suggests the presence of phenomenological bifurcations in brain dynamics associated with cognitive load. Hence, brain dynamics may fluctuate between criticality and other regimes depending upon context and behaviours.

  17. Side-emitting high-power LEDs and their application in illumination

    Science.gov (United States)

    West, Robert S.

    2002-11-01

    Due to the rapid increase in flux performance from High Power LED's, illumination is an exciting growth market for solid state lighting. Today a white LED is 100+ Lm per device. This is approximately an order of magnitude below the kLm metric used for illumination applications. The radiation pattern from the LED is key in increasing the usable flux resulting in improved systems optical performance. This advancement in radiation pattern will allow new market opportunities, which were not yet feasible. In the future this effect of usable lumens will become more important as the flux per package increases. The radiation pattern of the LEDs can be controlled to optimize performance, appearance, and shape of the secondary optics. This advantage is unique to LEDs and can greatly improve system performance, control, and cosmetic appeal for the application. This paper will review the side emitting lens design, the integrated performance of this technology to secondary optics and how the Luxeon side emitter enables improved performance by creating more useable lumens.

  18. Predicting the long tail of book sales: Unearthing the power-law exponent

    Science.gov (United States)

    Fenner, Trevor; Levene, Mark; Loizou, George

    2010-06-01

    The concept of the long tail has recently been used to explain the phenomenon in e-commerce where the total volume of sales of the items in the tail is comparable to that of the most popular items. In the case of online book sales, the proportion of tail sales has been estimated using regression techniques on the assumption that the data obeys a power-law distribution. Here we propose a different technique for estimation based on a generative model of book sales that results in an asymptotic power-law distribution of sales, but which does not suffer from the problems related to power-law regression techniques. We show that the proportion of tail sales predicted is very sensitive to the estimated power-law exponent. In particular, if we assume that the power-law exponent of the cumulative distribution is closer to 1.1 rather than to 1.2 (estimates published in 2003, calculated using regression by two groups of researchers), then our computations suggest that the tail sales of Amazon.com, rather than being 40% as estimated by Brynjolfsson, Hu and Smith in 2003, are actually closer to 20%, the proportion estimated by its CEO.

  19. On the power law of passive scalars in turbulence

    Science.gov (United States)

    Gotoh, Toshiyuki; Watanabe, Takeshi

    2015-11-01

    It has long been considered that the moments of the scalar increment with separation distance r obey power law with scaling exponents in the inertial convective range and the exponents are insensitive to variation of pumping of scalar fluctuations at large scales, thus the scaling exponents are universal. We examine the scaling behavior of the moments of increments of passive scalars 1 and 2 by using DNS up to the grid points of 40963. They are simultaneously convected by the same isotropic steady turbulence atRλ = 805 , but excited by two different methods. Scalar 1 is excited by the random scalar injection which is isotropic, Gaussian and white in time at law wavenumber band, while Scalar 2 is excited by the uniform mean scalar gradient. It is found that the local scaling exponents of the scalar 1 has a logarithmic correction, meaning that the moments of the scalar 1 do not obey simple power law. On the other hand, the moments of the scalar 2 is found to obey the well developed power law with exponents consistent with those in the literature. Physical reasons for the difference are explored. Grants-in-Aid for Scientific Research 15H02218 and 26420106, NIFS14KNSS050, HPCI project hp150088 and hp140024, JHPCN project jh150012.

  20. SPECIFIC FEATURES OF POWER CONSUMPTION OF LED DEVICES AND ACCOUNTING THEM IN CALCULATION OF ELECTRICAL NETWORKS

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The indicators of power consumption of lighting devices based on LEDs are studied depending on the supplied voltage. For the lamp and floodlight with LEDs active and reactive power, current and power factor as a function of voltage (which value changed in the range 200–245 V were experimentally determined. The analysis of experimental data demonstrated that due to the drivers in the specified voltage range the active power consumed by light devices remains practically unchanged. The reactive power of LED devices depends on the supplied voltage and is capacitive in its nature. In contrast with gas-discharge light sources the LED devices under study do not consume reactive power, but generate it. With the change of the supplied voltage from 200 to 245 V the value of the generated reactive power increases to 60 % for the floodlight and 50 % for the lamp. The LED floodlight has a low coefficient of active power. The current consumed by the floodlight has increased by 22 %, and by the lamp – by 13 %. The formulas for determining the maximum value of the length of the calculated section of single-phase group lines were developed, taking into account specific source data. LED light sources tend to feed by electric power by single-phase group lines. The number of lamps connected to single-phase lines is regulated by normative documents. Bearing this in mind as well as the small power of LED sources single-phase group lines are usually performed with conductors of the smallest possible cross section. The limit values of the length of the calculated section that correspond to a predetermined loss of voltage in line with ambient temperature from 15 to 60 °С were determined for them. The calculations demonstrated that for group lines that feed the LEDs, the choice of conductor cross-sections in accordance with permissible voltage loss is not critical. The determinant factor for the choice of the cross-section of the conductors of group electrical

  1. A theory of power-law distributions in financial market fluctuations.

    Science.gov (United States)

    Gabaix, Xavier; Gopikrishnan, Parameswaran; Plerou, Vasiliki; Stanley, H Eugene

    2003-05-15

    Insights into the dynamics of a complex system are often gained by focusing on large fluctuations. For the financial system, huge databases now exist that facilitate the analysis of large fluctuations and the characterization of their statistical behaviour. Power laws appear to describe histograms of relevant financial fluctuations, such as fluctuations in stock price, trading volume and the number of trades. Surprisingly, the exponents that characterize these power laws are similar for different types and sizes of markets, for different market trends and even for different countries--suggesting that a generic theoretical basis may underlie these phenomena. Here we propose a model, based on a plausible set of assumptions, which provides an explanation for these empirical power laws. Our model is based on the hypothesis that large movements in stock market activity arise from the trades of large participants. Starting from an empirical characterization of the size distribution of those large market participants (mutual funds), we show that the power laws observed in financial data arise when the trading behaviour is performed in an optimal way. Our model additionally explains certain striking empirical regularities that describe the relationship between large fluctuations in prices, trading volume and the number of trades.

  2. Power-law to Power-law Mapping of Blazar Spectra from Intergalactic Absorption

    International Nuclear Information System (INIS)

    Stecker, F W; Scully, S T

    2007-01-01

    We have derived a useful analytic approximation for determining the effect of intergalactic absorption on the γ-ray spectra of TeV blazars the energy range 0.2 TeV γ γ ) is approximately logarithmic. The effect of this energy dependence is to steepen intrinsic source spectra such that a source with an approximate power-law spectral index Γ s is converted to one with an observed spectral index Γ o ≅ Γ s + ΔΓ(z) where ΔΓ(z) is a linear function of z in the redshift range 0.05-0.4. We apply this approximation to the spectra of 7 TeV blazars

  3. Tunable power law in the desynchronization events of coupled chaotic electronic circuits

    International Nuclear Information System (INIS)

    Oliveira, Gilson F. de; Lorenzo, Orlando di; Chevrollier, Martine; Passerat de Silans, Thierry; Oriá, Marcos; Souza Cavalcante, Hugo L. D. de

    2014-01-01

    We study the statistics of the amplitude of the synchronization error in chaotic electronic circuits coupled through linear feedback. Depending on the coupling strength, our system exhibits three qualitatively different regimes of synchronization: weak coupling yields independent oscillations; moderate to strong coupling produces a regime of intermittent synchronization known as attractor bubbling; and stronger coupling produces complete synchronization. In the regime of moderate coupling, the probability distribution for the sizes of desynchronization events follows a power law, with an exponent that can be adjusted by changing the coupling strength. Such power-law distributions are interesting, as they appear in many complex systems. However, most of the systems with such a behavior have a fixed value for the exponent of the power law, while here we present an example of a system where the exponent of the power law is easily tuned in real time

  4. Preliminary limits on deviation from the inverse-square law of gravity in the solar system: a power-law parameterization

    International Nuclear Information System (INIS)

    Liu Meng-Yao; Zhong Ze-Hao; Han Yi-Chen; Wang Xiao-Yu; Yang Zong-Shui; Xie Yi

    2014-01-01

    New physics beyond the standard model of particles might cause a deviation from the inverse-square law of gravity. In some theories, it is parameterized by a power-law correction to the Newtonian gravitational force, which might originate from the simultaneous exchange of particles or modified and extended theories of gravity. Using the supplementary advances of the perihelia provided by INPOP10a (IMCCE, France) and EPM2011 (IAA RAS, Russia) ephemerides, we obtain preliminary limits on this correction. In our estimation, we take the Lense-Thirring effect due to the Sun's angular momentum into account. The parameters of the power-law correction and the uncertainty of the Sun's quadrupole moment are simultaneously estimated with the method of minimizing χ 2 . From INPOP10a, we find N = 0.605 for the exponent of the power-law correction. However, from EPM2011, we find that, although it yields N = 3.001, the estimated uncertainty in the Sun's quadrupole moment is much larger than the value given by current observations. This might be caused by the intrinsic nonlinearity in the power-law correction, which makes the estimation very sensitive to the supplementary advances of the perihelia. (research papers)

  5. Pascal (Yang Hui) triangles and power laws in the logistic map

    International Nuclear Information System (INIS)

    Velarde, Carlos; Robledo, Alberto

    2015-01-01

    We point out the joint occurrence of Pascal triangle patterns and power-law scaling in the standard logistic map, or more generally, in unimodal maps. It is known that these features are present in its two types of bifurcation cascades: period and chaotic-band doubling of attractors. Approximate Pascal triangles are exhibited by the sets of lengths of supercycle diameters and by the sets of widths of opening bands. Additionally, power-law scaling manifests along periodic attractor supercycle positions and chaotic band splitting points. Consequently, the attractor at the mutual accumulation point of the doubling cascades, the onset of chaos, displays both Gaussian and power-law distributions. Their combined existence implies both ordinary and exceptional statistical-mechanical descriptions of dynamical properties. (paper)

  6. BInGaN alloys nearly lattice-matched to GaN for high-power high-efficiency visible LEDs

    Science.gov (United States)

    Williams, Logan; Kioupakis, Emmanouil

    2017-11-01

    InGaN-based visible light-emitting diodes (LEDs) find commercial applications for solid-state lighting and displays, but lattice mismatch limits the thickness of InGaN quantum wells that can be grown on GaN with high crystalline quality. Since narrower wells operate at a higher carrier density for a given current density, they increase the fraction of carriers lost to Auger recombination and lower the efficiency. The incorporation of boron, a smaller group-III element, into InGaN alloys is a promising method to eliminate the lattice mismatch and realize high-power, high-efficiency visible LEDs with thick active regions. In this work, we apply predictive calculations based on hybrid density functional theory to investigate the thermodynamic, structural, and electronic properties of BInGaN alloys. Our results show that BInGaN alloys with a B:In ratio of 2:3 are better lattice matched to GaN compared to InGaN and, for indium fractions less than 0.2, nearly lattice matched. Deviations from Vegard's law appear as bowing of the in-plane lattice constant with respect to composition. Our thermodynamics calculations demonstrate that the solubility of boron is higher in InGaN than in pure GaN. Varying the Ga mole fraction while keeping the B:In ratio constant enables the adjustment of the (direct) gap in the 1.75-3.39 eV range, which covers the entire visible spectrum. Holes are strongly localized in non-bonded N 2p states caused by local bond planarization near boron atoms. Our results indicate that BInGaN alloys are promising for fabricating nitride heterostructures with thick active regions for high-power, high-efficiency LEDs.

  7. Energy consumption reduction in existing HVAC-R systems via a power law controlling kit

    International Nuclear Information System (INIS)

    Pinnola, C.F.; Vargas, J.V.C.; Buiar, C.L.; Ordonez, J.C.

    2015-01-01

    This paper presents an alternative solution for reducing energy consumption in heating, ventilation, air conditioning and refrigeration (HVAC-R) systems. For that, an existing typical commercial refrigeration system was equipped with a novel control system based on a power law, using a frequency inverter and a programmable logic controller (PLC). Hence, it was possible to compare the operation and energy consumption of the system with the power law control and with the on-off system, quantifying the obtained gains. The experimental unit consisted of a cooling chamber, an enclosing chamber (antechamber), and a vapor compression refrigeration system, i.e., an example of a practical commercial cooling system. A set of graphs shows the experimental measurements performed with the two systems. In this way, the measured temperatures in some selected points of the two systems, as well as the consumption in kWh for a period of 6 h and 10 min were compared in the tests. The main conclusions of this work are: i) The system operating with the power law control with respect to the conventional on-off control, showed energy consumption savings of up to 31% in a test period of 6 h and 10 min, and ii) The system compressor cycling frequency in the system operating with the power law control is smaller than with the traditional on-off system. Therefore, the study shows that the developed power law control kit has potential to be installed in any existing system with immediate significant energy savings with no need for HVAC-R hardware changes. - Highlights: • An energy consumption reduction strategy for HVAC-R systems is presented. • Power law and on-off control actions are experimentally compared. • Energy savings of 31% were obtained with power law control. • Compressor cycling frequency is smaller with power law control. • Power law control kit has potential to be installed in any existing system

  8. Proposed law concerning the phase-out of nuclear power

    International Nuclear Information System (INIS)

    1997-01-01

    This Government bill that will be presented to the Swedish Parliament, gives the Government the right to revoke the licence of operating a nuclear power plant at a certain time. The operator is given the right to a financial compensation when the licence is revoked, in line with the rules in the expropriation laws. Safety aspects of operation of nuclear installations are not regulated in this law, i.e. the law can not be used when the operating licence is revoked due to safety reasons

  9. Two-phase flow in porous media: power-law scaling of effective permeability

    Energy Technology Data Exchange (ETDEWEB)

    Groeva, Morten; Hansen, Alex, E-mail: Morten.Grova@ntnu.no, E-mail: Alex.Hansen@ntnu.no [Department of Physics, NTNU, NO-7491 Trondheim (Norway)

    2011-09-15

    A recent experiment has reported power-law scaling of effective permeability of two-phase flow with respect to capillary number for a two-dimensional model porous medium. In this paper, we consider the simultaneous flow of two phases through a porous medium under steady-state conditions, fixed total flow-rate and saturation, using a two-dimensional network simulator. We obtain power-law exponents for the scaling of effective permeability with respect to capillary number. The simulations are performed both for viscosity matched fluids and for a high viscosity ratio resembling that of air and water. Good power-law behaviour is found for both cases. Different exponents are found, depending on saturation.

  10. Poissonian renormalizations, exponentials, and power laws.

    Science.gov (United States)

    Eliazar, Iddo

    2013-05-01

    This paper presents a comprehensive "renormalization study" of Poisson processes governed by exponential and power-law intensities. These Poisson processes are of fundamental importance, as they constitute the very bedrock of the universal extreme-value laws of Gumbel, Fréchet, and Weibull. Applying the method of Poissonian renormalization we analyze the emergence of these Poisson processes, unveil their intrinsic dynamical structures, determine their domains of attraction, and characterize their structural phase transitions. These structural phase transitions are shown to be governed by uniform and harmonic intensities, to have universal domains of attraction, to uniquely display intrinsic invariance, and to be intimately connected to "white noise" and to "1/f noise." Thus, we establish a Poissonian explanation to the omnipresence of white and 1/f noises.

  11. Evaluation of 'period-generated' control laws for the time-optimal control of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.

    1988-01-01

    Time-Optimal control of neutronic power has recently been achieved by developing control laws that determine the actuator mechanism velocity necessary to produce a specified reactor period. These laws are designated as the 'MIT-SNL Period-Generated Minimum Time Control Laws'. Relative to time-optimal response, they function by altering the rate of change of reactivity so that the instantaneous period is stepped from infinity to its minimum allowed value, held at that value until the desired power level is attained, and then stepped back to infinity. The results of a systematic evaluation of these laws are presented. The behavior of each term in the control laws is shown and the capability of these laws to control properly the reactor power is demonstrated. Factors affecting the implementation of these laws, such as the prompt neutron lifetime and the differential reactivity worth of the actuators, are discussed. Finally, the results of an experimental study in which these laws were used to adjust the power of the 5 MWt MIT Research Reactor are shown. The information presented should be of interest to those designing high performance control systems for test, spacecraft, or, in certain instances, commercial reactors

  12. COSMOLOGY OF CHAMELEONS WITH POWER-LAW COUPLINGS

    International Nuclear Information System (INIS)

    Mota, David F.; Winther, Hans A.

    2011-01-01

    In chameleon field theories, a scalar field can couple to matter with gravitational strength and still evade local gravity constraints due to a combination of self-interactions and the couplings to matter. Originally, these theories were proposed with a constant coupling to matter; however, the chameleon mechanism also extends to the case where the coupling becomes field dependent. We study the cosmology of chameleon models with power-law couplings and power-law potentials. It is found that these generalized chameleons, when viable, have a background expansion very close to ΛCDM, but can in some special cases enhance the growth of the linear perturbations at low redshifts. For the models we consider, it is found that this region of the parameter space is ruled out by local gravity constraints. Imposing a coupling to dark matter only, the local constraints are avoided, and it is possible to have observable signatures on the linear matter perturbations.

  13. Constraints on the tensor-to-scalar ratio for non-power-law models

    International Nuclear Information System (INIS)

    Vázquez, J. Alberto; Bridges, M.; Ma, Yin-Zhe; Hobson, M.P.

    2013-01-01

    Recent cosmological observations hint at a deviation from the simple power-law form of the primordial spectrum of curvature perturbations. In this paper we show that in the presence of a tensor component, a turn-over in the initial spectrum is preferred by current observations, and hence non-power-law models ought to be considered. For instance, for a power-law parameterisation with both a tensor component and running parameter, current data show a preference for a negative running at more than 2.5σ C.L. As a consequence of this deviation from a power-law, constraints on the tensor-to-scalar ratio r are slightly broader. We also present constraints on the inflationary parameters for a model-independent reconstruction and the Lasenby and Doran (LD) model. In particular, the constraints on the tensor-to-scalar ratio from the LD model are: r LD = 0.11±0.024. In addition to current data, we show expected constraints from Planck-like and CMB-Pol sensitivity experiments by using Markov-Chain-Monte-Carlo sampling chains. For all the models, we have included the Bayesian Evidence to perform a model selection analysis. The Bayes factor, using current observations, shows a strong preference for the LD model over the standard power-law parameterisation, and provides an insight into the accuracy of differentiating models through future surveys

  14. Dual plane problems for creeping flow of power-law incompressible medium

    Directory of Open Access Journals (Sweden)

    Dmitriy S. Petukhov

    2016-09-01

    Full Text Available In this paper, we consider the class of solutions for a creeping plane flow of incompressible medium with power-law rheology, which are written in the form of the product of arbitrary power of the radial coordinate by arbitrary function of the angular coordinate of the polar coordinate system covering the plane. This class of solutions represents the asymptotics of fields in the vicinity of singular points in the domain occupied by the examined medium. We have ascertained the duality of two problems for a plane with wedge-shaped notch, at which boundaries in one of the problems the vector components of the surface force vanish, while in the other—the vanishing components are the vector components of velocity, We have investigated the asymptotics and eigensolutions of the dual nonlinear eigenvalue problems in relation to the rheological exponent and opening angle of the notch for the branch associated with the eigenvalue of the Hutchinson–Rice–Rosengren problem learned from the problem of stress distribution over a notched plane for a power law medium. In the context of the dual problem we have determined the velocity distribution in the flow of power-law medium at the vertex of a rigid wedge, We have also found another two eigenvalues, one of which was determined by V. V. Sokolovsky for the problem of power-law fluid flow in a convergent channel.

  15. Empirical Scaling Laws of Neutral Beam Injection Power in HL-2A Tokamak

    International Nuclear Information System (INIS)

    Cao Jian-Yong; Wei Hui-Ling; Liu He; Yang Xian-Fu; Zou Gui-Qing; Yu Li-Ming; Li Qing; Luo Cui-Wen; Pan Yu-Dong; Jiang Shao-Feng; Lei Guang-Jiu; Li Bo; Rao Jun; Duan Xu-Ru

    2015-01-01

    We present an experimental method to obtain neutral beam injection (NBI) power scaling laws with operating parameters of the NBI system on HL-2A, including the beam divergence angle, the beam power transmission efficiency, the neutralization efficiency and so on. With the empirical scaling laws, the estimating power can be obtained in every shot of experiment on time, therefore the important parameters such as the energy confinement time can be obtained precisely. The simulation results by the tokamak simulation code (TSC) show that the evolution of the plasma parameters is in good agreement with the experimental results by using the NBI power from the empirical scaling law. (paper)

  16. Mathematical modeling for laminar flow of power law fluid in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Renato A.; Mesquita, Maximilian S. [Universidade Federal do Espirito Santo (UFES), Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Dept. de Engenharias e Computacao

    2010-07-01

    In this paper, the macroscopic equations for laminar power-law fluid flow is obtained for a porous medium starting from traditional equations (Navier-Stokes). Then, the volume averaging is applied in traditional transport equations with the power-law fluid model. This procedure leads to macroscopic transport equations set for non-Newtonian fluid. (author)

  17. A common mode of origin of power laws in models of market and earthquake

    Science.gov (United States)

    Bhattacharyya, Pratip; Chatterjee, Arnab; Chakrabarti, Bikas K.

    2007-07-01

    We show that there is a common mode of origin for the power laws observed in two different models: (i) the Pareto law for the distribution of money among the agents with random-saving propensities in an ideal gas-like market model and (ii) the Gutenberg-Richter law for the distribution of overlaps in a fractal-overlap model for earthquakes. We find that the power laws appear as the asymptotic forms of ever-widening log-normal distributions for the agents’ money and the overlap magnitude, respectively. The identification of the generic origin of the power laws helps in better understanding and in developing generalized views of phenomena in such diverse areas as economics and geophysics.

  18. Analyzing Thermal Module Developments and Trends in High-Power LED

    Directory of Open Access Journals (Sweden)

    Jung-Chang Wang

    2014-01-01

    Full Text Available The solid-state light emitting diode (SSLED has been verified as consumer-electronic products and attracts attention to indoor and outdoor lighting lamp, which has a great benefit in saving energy and environmental protection. However, LED junction temperature will influence the luminous efficiency, spectral color, life cycle, and stability. This study utilizes thermal performance experiments with the illumination-analysis method and window program (vapour chamber thermal module, VCTM V1.0 to investigate and analyze the high-power LED (Hi-LED lighting thermal module, in order to achieve the best solution of the fin parameters under the natural convection. The computing core of the VCTM program employs the theoretical thermal resistance analytical approach with iterative convergence stated in this study to obtain a numerical solution. Results showed that the best geometry of thermal module is 4.4 mm fin thickness, 9.4 mm fin pitch, and 37 mm fin height with the LED junction temperature of 58.8°C. And the experimental thermal resistances are in good agreement with the theoretical thermal resistances; calculating error between measured data and simulation results is no more than ±7%. Thus, the Hi-LED illumination lamp has high life cycle and reliability.

  19. Estudo morfométrico da terapia LED de baixa potência em tendinite de ratos Morphometric study of low power LED therapy tendonitis in rats

    Directory of Open Access Journals (Sweden)

    José Mário Nunes da Silva

    2011-12-01

    Full Text Available A terapia LED de baixa potência possui efeitos analgésico e antiinflamatório. O objetivo desse estudo foi analisar a ação da terapia com LED de baixa potência na reparação tendínea por meio de histologia e histomorfometria. Foram usados 25 ratos Wistar, de 220 a 250 g, divididos em três grupos experimentais avaliados no 7º e 14º dia: A, tendinite induzida sem tratamento; B, tendinite induzida tratada com LED de baixa potência, densidade de energia 4 J/cm² por 120 segundos; e C, sem indução de tendinite. A histomorfometria mostrou-se altamente significativa (p0,05. As análises histológica e histomorfométrica demonstraram qualitativo e quantitativo aumento no número de fibroblastos aos sete dias de tratamento, e das fibras colágenas, aos 14 dias, para grupo tratado com LED de baixa potência em relação ao grupo sadio (C. O mesmo não foi percebido quando relacionado ao grupo tendinite (A14.The low power LED therapy has analgesic and anti-inflammatory effects. The objective of this study was to analyze the action of therapy with low power LED on the tendon repair, using histology and histomorphometry. Were used 25 Wistar rats, with 220 to 250 g, divided into three experimental groups (7 and 14 days: A7 and A14 induced tendonitis without treatment; B7 and B14, induced tendinitis treated with LED low power density energy 4 J /cm² for 120 seconds; and C, without induction of tendinitis. Histomorphometry was highly significant (p 0.05. Histology and histomorphometry analysis demonstrated qualitative and quantitative increase in the number of fibroblasts to seven days of treatment, and collagen fibers at 14 days for the group treated with LED low power compared to the healthy group (C. But it is unclear even when related to the tendinitis group (A14.

  20. Classical orbits in power-law potentials

    International Nuclear Information System (INIS)

    Grant, A.K.; Rosner, J.L.

    1994-01-01

    The motion of bodies in power-law potentials of the form V(r)=λr α has been of interest ever since the time of Newton and Hooke. Aspects of the relation between powers α and bar α, where (α+2)(bar α+2)=4, are derived for classical motion and the relation to the quantum-mechanical problem is given. An improvement on a previous expression for the WKB quantization condition for nonzero orbital angular momenta is obtained. Relations with previous treatments, such as those of Newton, Bertrand, Bohlin, Faure, and Arnold, are noted, and a brief survey of the literature on the problem over more than three centuries is given

  1. Determining Rheological Parameters of Generalized Yield-Power-Law Fluid Model

    Directory of Open Access Journals (Sweden)

    Stryczek Stanislaw

    2004-09-01

    Full Text Available The principles of determining rheological parameters of drilling muds described by a generalized yield-power-law are presented in the paper. Functions between tangent stresses and shear rate are given. The conditions of laboratory measurements of rheological parameters of generalized yield-power-law fluids are described and necessary mathematical relations for rheological model parameters given. With the block diagrams, the methodics of numerical solution of these relations has been presented. Rheological parameters of an exemplary drilling mud have been calculated with the use of this numerical program.

  2. Electrohydrodynamic stability of two stratified power law liquid in couette flow

    International Nuclear Information System (INIS)

    Eldabe, N.T.

    1988-01-01

    Consideration is given to the stability of the flow of two power law liquids under the influence of normal electric field between two infinite parallel planes when one of the planes moves with constant velocity in its own plane. It is found that the electric fields have a dramatic effect and can be chosen to stabilize or destabilize the flow. The effects of the power law parameters on the problem are examinated

  3. Power-law versus exponential relaxation of {sup 29}Si nucleus spins in Si:B crystals

    Energy Technology Data Exchange (ETDEWEB)

    Koplak, O.V. [Institute of Problems of Chemical Physics, 142432 Chernogolovka, Moscow (Russian Federation); Taras Shevchenko Kiev National University and National Academy of Sciences, 01033 Kiev (Ukraine); Talantsev, A.D., E-mail: adt@icp.ac.ru [Institute of Problems of Chemical Physics, 142432 Chernogolovka, Moscow (Russian Federation); Morgunov, R.B. [Institute of Problems of Chemical Physics, 142432 Chernogolovka, Moscow (Russian Federation); Sholokhov Moscow State University for the Humanities, 109240 Moscow (Russian Federation)

    2016-02-15

    The Si:B micro-crystals enriched with {sup 29}Si isotope have been studied by high resolution nuclear magnetic resonance (NMR) in the 300–800 K temperature range. The recovery of nuclear magnetization saturated by radiofrequency impulses follows pure power-law kinetics at 300 K, while admixture of exponential relaxation takes place at 500 K. The power-law relaxation corresponds to direct electron–nuclear relaxation due to the inhomogeneous distribution of paramagnetic centers, while exponential kinetics corresponds to the nuclear spin diffusion mechanism. The inhomogeneous distribution of deformation defects is a most probable reason of the power-law kinetics of nuclear spin relaxation. - Highlights: • {sup 29}Si nuclear magnetization relaxation follows mixed power-exponential law. • Power-law corresponds to direct electron–nuclear relaxation. • Admixture of exponential relaxation corresponds to the nuclear spin diffusion. • Inhomogeneously distributed deformation defects are responsible for power low. • Homogeneously distributed Boron acceptors are responsible for exponential part.

  4. Poissonian renormalizations, exponentials, and power laws

    Science.gov (United States)

    Eliazar, Iddo

    2013-05-01

    This paper presents a comprehensive “renormalization study” of Poisson processes governed by exponential and power-law intensities. These Poisson processes are of fundamental importance, as they constitute the very bedrock of the universal extreme-value laws of Gumbel, Fréchet, and Weibull. Applying the method of Poissonian renormalization we analyze the emergence of these Poisson processes, unveil their intrinsic dynamical structures, determine their domains of attraction, and characterize their structural phase transitions. These structural phase transitions are shown to be governed by uniform and harmonic intensities, to have universal domains of attraction, to uniquely display intrinsic invariance, and to be intimately connected to “white noise” and to “1/f noise.” Thus, we establish a Poissonian explanation to the omnipresence of white and 1/f noises.

  5. Relation of the second law of thermodynamics to the power conversion of energy fluctuations

    International Nuclear Information System (INIS)

    Yater, J.C.

    1979-01-01

    The relation of the second law of thermodynamics to the power conversion of fluctuation energy is analyzed using the master equation of the model for the conversion circuit. The performance equation for independent particles shows that the power-conversion performance is given by the second law both for classical and quantum-effect diodes. The relation of the second law to power-conversion models based on the theoretical and experimental results for diode performance for interacting particles exhibiting many-body, multiparticle, or other anomalous and excess-current effects is examined. The performance equations are derived from the master equation for models for interacting particles to determine the conditions required by the second law for power conversion. These conditions are given in terms of the distribution throughout the power-conversion circuit for all the parameters that determine the particle and multiparticle barrier-crossing probability such as the effective mass and spectral density functions. Circuits for spectroscopic measurements for power-conversion circuits with interacting particles are noted. Using selected experimental values for the diode nonlinearity factors in these circuits, open circuit voltages are computed that are not predicted by the second law of thermodynamics

  6. Dynamics of a map with a power-law tail

    International Nuclear Information System (INIS)

    Botella-Soler, V; Ros, J; Oteo, J A

    2009-01-01

    We analyze a one-dimensional piecewise continuous discrete model proposed originally in studies on population ecology. The map is composed of a linear part and a power-law decreasing piece, and has three parameters. The system presents both regular and chaotic behavior. We study numerically and, in part, analytically different bifurcation structures. Particularly interesting is the description of the abrupt order-to-chaos transition mediated by an attractor made of an infinite number of limit cycles with only a finite number of different periods. It is shown that the power-law piece in the map is at the origin of this type of bifurcation. The system exhibits interior crises and crisis-induced intermittency.

  7. Characterizing and predicting the robustness of power-law networks

    International Nuclear Information System (INIS)

    LaRocca, Sarah; Guikema, Seth D.

    2015-01-01

    Power-law networks such as the Internet, terrorist cells, species relationships, and cellular metabolic interactions are susceptible to node failures, yet maintaining network connectivity is essential for network functionality. Disconnection of the network leads to fragmentation and, in some cases, collapse of the underlying system. However, the influences of the topology of networks on their ability to withstand node failures are poorly understood. Based on a study of the response of 2000 randomly-generated power-law networks to node failures, we find that networks with higher nodal degree and clustering coefficient, lower betweenness centrality, and lower variability in path length and clustering coefficient maintain their cohesion better during such events. We also find that network robustness, i.e., the ability to withstand node failures, can be accurately predicted a priori for power-law networks across many fields. These results provide a basis for designing new, more robust networks, improving the robustness of existing networks such as the Internet and cellular metabolic pathways, and efficiently degrading networks such as terrorist cells. - Highlights: • Examine relationship between network topology and robustness to failures. • Relationship is statistically significant for scale-free networks. • Use statistical models to estimate robustness to failures for real-world networks

  8. Phase diagram of power law and Lennard-Jones systems: Crystal phases

    International Nuclear Information System (INIS)

    Travesset, Alex

    2014-01-01

    An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists with the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed

  9. A Single-Stage High-Power-Factor Light-Emitting Diode (LED Driver with Coupled Inductors for Streetlight Applications

    Directory of Open Access Journals (Sweden)

    Chun-An Cheng

    2017-02-01

    Full Text Available This paper presents and implements a single-stage high-power-factor light-emitting diode (LED driver with coupled inductors, suitable for streetlight applications. The presented LED driver integrates an interleaved buck-boost power factor correction (PFC converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power conversion circuit. Coupled inductors inside the interleaved buck-boost PFC converter sub-circuit are designed to operate in discontinuous conduction mode (DCM for achieving input-current shaping, and the half-bridge-type series resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the presented driver features a high power factor, low total harmonic distortion (THD of input current, and soft switching. Finally, a prototype driver is developed and implemented to supply a 165-W-rated LED streetlight module with utility-line input voltages ranging from 210 to 230 V. Experimental results demonstrate that high power factor (>0.99, low utility-line current THD (<7%, low-output voltage ripples (<1%, low-output current ripples (<10%, and high circuit efficiency (>90% are obtained in the presented single-stage driver for LED streetlight applications.

  10. The power of law : Spinoza’s contribution to legal theory

    NARCIS (Netherlands)

    Gribnau, J.L.M.

    1995-01-01

    Spinoza’s legal theoretical ideas are based on psychological and sociological regularities in human behaviour of knowledge. His naturalistic and descriptive approach of the relationship between law and power shows that the exercise of state power on that basis - within the constitutional constraints

  11. The improvement of photocatalytic processes: Design of a photoreactor using high-power LEDs

    Directory of Open Access Journals (Sweden)

    Marzieh Khademalrasool

    2016-09-01

    Full Text Available This paper is an attempt to survey the benefits of a well-designed photoreactor containing just 6 ultraviolet (UV high power light emitting diodes (HPLEDs; the power and wavelength of each UV HPLED are 1 W and 365 nm, respectively, the latter being an efficient source for photocatalytic studies. Although the experiment with the 365-nm LEDs is reported here, other LEDs were predicted for conducting similar experiments including green photocatalytic ones. We installed diodes with respect to the luminescence intensity distribution curves (LIDCs or intensity patterns. Then, in order to compare the efficiency of the UV-HPLEDs of the HP-LED photoreactor (HPLED-PhR with that of traditional UV lamps which are extensively used in photocatalytic processes, a set of UV HPLEDs was designed and made up. Next, the performance of HPLED-PhR was compared with that of a traditional fluorescent lamp photoreactor (FL-PhR. As a typical photocatalytic experiment, Zinc Oxide (ZnO nanoparticles were synthesized via co-precipitation method and used as photocatalyst for purification of water polluted with the reactive blue dye (RB, under UV irradiation in two photoreactors. The results showed that the rate of photocatalytic reaction under the UV-LEDs was two times greater than the rate under the traditional fluorescent UV lamps, while both electrical power consumption and manufacturing cost of the HPLED-PhR were less than a quarter of them for the FL-PhR.

  12. Power Laws, Scale-Free Networks and Genome Biology

    CERN Document Server

    Koonin, Eugene V; Karev, Georgy P

    2006-01-01

    Power Laws, Scale-free Networks and Genome Biology deals with crucial aspects of the theoretical foundations of systems biology, namely power law distributions and scale-free networks which have emerged as the hallmarks of biological organization in the post-genomic era. The chapters in the book not only describe the interesting mathematical properties of biological networks but moves beyond phenomenology, toward models of evolution capable of explaining the emergence of these features. The collection of chapters, contributed by both physicists and biologists, strives to address the problems in this field in a rigorous but not excessively mathematical manner and to represent different viewpoints, which is crucial in this emerging discipline. Each chapter includes, in addition to technical descriptions of properties of biological networks and evolutionary models, a more general and accessible introduction to the respective problems. Most chapters emphasize the potential of theoretical systems biology for disco...

  13. Judicial law-making: Unlocking the creative powers of judges in ...

    African Journals Online (AJOL)

    ... the creative powers of judges in terms of Section 39(2) of the constitution. ... that judges do indeed have a law-making function in the process of interpretation. ... The article examines the extent to which the judiciary can use this power in a ...

  14. Statistical interpretation of transient current power-law decay in colloidal quantum dot arrays

    Energy Technology Data Exchange (ETDEWEB)

    Sibatov, R T, E-mail: ren_sib@bk.ru [Ulyanovsk State University, 432000, 42 Leo Tolstoy Street, Ulyanovsk (Russian Federation)

    2011-08-01

    A new statistical model of the charge transport in colloidal quantum dot arrays is proposed. It takes into account Coulomb blockade forbidding multiple occupancy of nanocrystals and the influence of energetic disorder of interdot space. The model explains power-law current transients and the presence of the memory effect. The fractional differential analogue of the Ohm law is found phenomenologically for nanocrystal arrays. The model combines ideas that were considered as conflicting by other authors: the Scher-Montroll idea about the power-law distribution of waiting times in localized states for disordered semiconductors is applied taking into account Coulomb blockade; Novikov's condition about the asymptotic power-law distribution of time intervals between successful current pulses in conduction channels is fulfilled; and the carrier injection blocking predicted by Ginger and Greenham (2000 J. Appl. Phys. 87 1361) takes place.

  15. Statistical interpretation of transient current power-law decay in colloidal quantum dot arrays

    International Nuclear Information System (INIS)

    Sibatov, R T

    2011-01-01

    A new statistical model of the charge transport in colloidal quantum dot arrays is proposed. It takes into account Coulomb blockade forbidding multiple occupancy of nanocrystals and the influence of energetic disorder of interdot space. The model explains power-law current transients and the presence of the memory effect. The fractional differential analogue of the Ohm law is found phenomenologically for nanocrystal arrays. The model combines ideas that were considered as conflicting by other authors: the Scher-Montroll idea about the power-law distribution of waiting times in localized states for disordered semiconductors is applied taking into account Coulomb blockade; Novikov's condition about the asymptotic power-law distribution of time intervals between successful current pulses in conduction channels is fulfilled; and the carrier injection blocking predicted by Ginger and Greenham (2000 J. Appl. Phys. 87 1361) takes place.

  16. Indian English Evolution and Focusing Visible Through Power Laws

    Directory of Open Access Journals (Sweden)

    Vineeta Chand

    2017-11-01

    Full Text Available New dialect emergence and focusing in language contact settings is difficult to capture and date in terms of global structural dialect stabilization. This paper explores whether diachronic power law frequency distributions can provide evidence of dialect evolution and new dialect focusing, by considering the quantitative frequency characteristics of three diachronic Indian English (IE corpora (1970s–2008. The results demonstrate that IE consistently follows power law frequency distributions and the corpora are each best fit by Mandelbrot’s Law. Diachronic changes in the constants are interpreted as evidence of lexical and syntactic collocational focusing within the process of new dialect formation. Evidence of new dialect focusing is also visible through apparent time comparison of spoken and written data. Age and gender-separated sub-corpora of the most recent corpus show minimal deviation, providing apparent time evidence for emerging IE dialect stability. From these findings, we extend the interpretation of diachronic changes in the β coefficient—as indicative of changes in the degree of synthetic/analytic structure—so that β is also sensitive to grammaticalization and changes in collocational patterns.

  17. Blinking in quantum dots: The origin of the grey state and power law statistics

    Science.gov (United States)

    Ye, Mao; Searson, Peter C.

    2011-09-01

    Quantum dot (QD) blinking is characterized by switching between an “on” state and an “off” state, and a power-law distribution of on and off times with exponents from 1.0 to 2.0. The origin of blinking behavior in QDs, however, has remained a mystery. Here we describe an energy-band model for QDs that captures the full range of blinking behavior reported in the literature and provides new insight into features such as the gray state, the power-law distribution of on and off times, and the power-law exponents.

  18. On the dynamics of the power law inflation due to an exponential potential

    International Nuclear Information System (INIS)

    Yokohama, Jun'ichi; Maeda, Kei-ichi; Tokyo Univ.

    1988-01-01

    The power law inflationary universe model induced by a scalar field with an exponential potential is studied. A dissipation term due to particle creation is introduced in the inflation's classical equation of motion. It is shown that the power index of the inflation increases prominently with an adequate viscosity. Consequently, even in theories with a rather steep exponential such as some supergravity or superstring models, it turns out that a 'realistic' power law inflation (with a power index p> or approx.10) is possible. (orig.)

  19. The speed-curvature power law in Drosophila larval locomotion.

    Science.gov (United States)

    Zago, Myrka; Lacquaniti, Francesco; Gomez-Marin, Alex

    2016-10-01

    We report the discovery that the locomotor trajectories of Drosophila larvae follow the power-law relationship between speed and curvature previously found in the movements of human and non-human primates. Using high-resolution behavioural tracking in controlled but naturalistic sensory environments, we tested the law in maggots tracing different trajectory types, from reaching-like movements to scribbles. For most but not all flies, we found that the law holds robustly, with an exponent close to three-quarters rather than to the usual two-thirds found in almost all human situations, suggesting dynamic effects adding on purely kinematic constraints. There are different hypotheses for the origin of the law in primates, one invoking cortical computations, another viscoelastic muscle properties coupled with central pattern generators. Our findings are consistent with the latter view and demonstrate that the law is possible in animals with nervous systems orders of magnitude simpler than in primates. Scaling laws might exist because natural selection favours processes that remain behaviourally efficient across a wide range of neural and body architectures in distantly related species. © 2016 The Authors.

  20. Power-law Decay and the Ergodic-Nonergodic Transition in Simple Fluids

    OpenAIRE

    Spyridis, Paul; Mazenko, Gene F.

    2013-01-01

    It is well known that mode coupling theory (MCT) leads to a two step power-law time decay in dense simple fluids. We show that much of the mathematical machinery used in the MCT analysis can be taken over to the analysis of the systematic theory developed in the Fundamental Theory of Statistical Particle Dynamics (arXiv:0905.4904). We show how the power-law exponents can be computed in the second-order approximation where we treat hard-sphere fluids with statics described by the Percus-Yevick...

  1. Problems of cartel law in license contracts within the power economy

    International Nuclear Information System (INIS)

    Hueffer, U.

    1992-01-01

    First the licence contract is presented as a particularly important instrument of the power economy. In a second step a link is established with cartel law; that is, the special status of the power economy under cartel law and the significance of the licence contract within this context are illuminated. On this basis then, a very controversial complex of problems is entered into: the assessment of so-called expiration clauses in licence contracts, i.e. the legal situation upon expiration of a licence contract. It turns out that qualms about the time value being the takeover price have no legal basis. The fact that they were expressed at all is due to the lack of a synopsis of the relevant subareas of commercial law. Scientific purposes require a synopsis of the commercial law concerned rather than an argument in which each party splits off single aspects of the issue. (orig./HSCH) [de

  2. Unconfined Unsteady Laminar Flow of a Power-Law Fluid across a Square Cylinder

    Directory of Open Access Journals (Sweden)

    Asterios Pantokratoras

    2016-11-01

    Full Text Available The flow of a non-Newtonian, power-law fluid, directed normally to a horizontal cylinder with square cross-section (two-dimensional flow is considered in the present paper. The problem is investigated numerically with a very large calculation domain in order that the flow could be considered unconfined. The investigation covers the power-law index from 0.1 up to 2 and the Reynolds number ranges from 60 to 160. Over this range of Reynolds numbers the flow is unsteady. It is found that the drag coefficient and the Strouhal number are higher in a confined flow compared to those of an unconfined flow. In addition some flow characteristics are lost in a confined flow. Complete results for the drag coefficient and Strouhal number in the entire shear-thinning and shear-thickening region have been produced. In shear-thinning fluids chaotic structures exist which diminish at higher values of power-law index. This study represents the first investigation of unsteady, non-Newtonian power-law flow past a square cylinder in an unconfined field.

  3. Preinflationary dynamics in loop quantum cosmology: Power-law potentials

    Science.gov (United States)

    Shahalam, M.; Sharma, Manabendra; Wu, Qiang; Wang, Anzhong

    2017-12-01

    In this paper, we study the preinflationary dynamics for the power-law potential [V (ϕ )∝ϕn] with n consideration and compare our results with the ones obtained previously for different potentials.

  4. Energy law. The legal boundary conditions of power supply. 2. rev. ed.

    International Nuclear Information System (INIS)

    Stuhlmacher, Gerd; Stappert, Holger; Jansen, Guido

    2015-01-01

    Now appearing in its second edition, this book presents a comprehensive overview of the legal framework governing the energy sector. It provides readily understandable coverage, across the relevant subfields of law, of the legal regulations applicable to any manner of activity in the energy sector along with a wealth of practical advice on the interpretation and application of legal provisions. The content has been thoroughly revised, updated to reflect the current status of legislation and supplemented with numerous chapters. The 2014 amendment of the Renewable Energy Law (EEG) and its practical impact have also been taken into account. The following topics are covered amongst others: unbundling of network operation; connection and access to networks and metering; network charges and incentive regulation; easement contracts; energy supply and basic services; energy and electricity taxes; cartel law, law on operating aids, procurement law; energy trade OTC and at exchanges; energy trade surveillance law; fuel production and fracking; conventional and nuclear power production; renewable energy production (including offshore production); energy storage and power-to-gas; transmission line construction; climate protection (including the 2014 EEG, emission trade and the Law on the Promotion of Renewable Energy in the Heat Sector); cogeneration law, district heating and contracting; and investment protection.

  5. A Dual Power Law Distribution for the Stellar Initial Mass Function

    Science.gov (United States)

    Hoffmann, Karl Heinz; Essex, Christopher; Basu, Shantanu; Prehl, Janett

    2018-05-01

    We introduce a new dual power law (DPL) probability distribution function for the mass distribution of stellar and substellar objects at birth, otherwise known as the initial mass function (IMF). The model contains both deterministic and stochastic elements, and provides a unified framework within which to view the formation of brown dwarfs and stars resulting from an accretion process that starts from extremely low mass seeds. It does not depend upon a top down scenario of collapsing (Jeans) masses or an initial lognormal or otherwise IMF-like distribution of seed masses. Like the modified lognormal power law (MLP) distribution, the DPL distribution has a power law at the high mass end, as a result of exponential growth of mass coupled with equally likely stopping of accretion at any time interval. Unlike the MLP, a power law decay also appears at the low mass end of the IMF. This feature is closely connected to the accretion stopping probability rising from an initially low value up to a high value. This might be associated with physical effects of ejections sometimes (i.e., rarely) stopping accretion at early times followed by outflow driven accretion stopping at later times, with the transition happening at a critical time (therefore mass). Comparing the DPL to empirical data, the critical mass is close to the substellar mass limit, suggesting that the onset of nuclear fusion plays an important role in the subsequent accretion history of a young stellar object.

  6. Revision of by-laws about effluents of EdF's nuclear power plants

    International Nuclear Information System (INIS)

    2002-01-01

    In France, in application of the clean water law from January 3, 1992 and since the decree 95-540 from May 4, 1995, each basic nuclear facility receives a single permission which covers both its water takes and its radioactive and non-radioactive effluents. This decree, initially dedicated to new facilities has been enlarged to all existing installations for which the prefectorial by-laws have reached their date-line. Thus, up to now, five inter-ministerial by-laws have renewed the permissions of water takes and effluents evacuation of the power plants of Saint-Laurent-des-Eaux (Loir-et-Cher), Flamanville (Manche), Paluel (Seine-Maritime), Belleville (Cher) and Saint-Alban (Isere). These by-laws foresee an important abatement of the effluents and concern more particularly the tritium, 14 C, the iodine isotopes and also some other non-radioactive chemical compounds. This document is a compilation of all revised by-laws about effluents and concerning the nuclear power plants listed above. (J.S.)

  7. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  8. Using Power-Law Degree Distribution to Accelerate PageRank

    Directory of Open Access Journals (Sweden)

    Zhaoyan Jin

    2012-12-01

    Full Text Available The PageRank vector of a network is very important, for it can reflect the importance of a Web page in the World Wide Web, or of a people in a social network. However, with the growth of the World Wide Web and social networks, it needs more and more time to compute the PageRank vector of a network. In many real-world applications, the degree and PageRank distributions of these complex networks conform to the Power-Law distribution. This paper utilizes the degree distribution of a network to initialize its PageRank vector, and presents a Power-Law degree distribution accelerating algorithm of PageRank computation. Experiments on four real-world datasets show that the proposed algorithm converges more quickly than the original PageRank algorithm.

  9. Spreading law of non-Newtonian power-law liquids on a spherical substrate by an energy-balance approach.

    Science.gov (United States)

    Iwamatsu, Masao

    2017-07-01

    The spreading of a cap-shaped spherical droplet of non-Newtonian power-law liquids, both shear-thickening and shear-thinning liquids, that completely wet a spherical substrate is theoretically investigated in the capillary-controlled spreading regime. The crater-shaped droplet model with the wedge-shaped meniscus near the three-phase contact line is used to calculate the viscous dissipation near the contact line. Then the energy balance approach is adopted to derive the equation that governs the evolution of the contact line. The time evolution of the dynamic contact angle θ of a droplet obeys a power law θ∼t^{-α} with the spreading exponent α, which is different from Tanner's law for Newtonian liquids and those for non-Newtonian liquids on a flat substrate. Furthermore, the line-tension dominated spreading, which could be realized on a spherical substrate for late-stage of spreading when the contact angle becomes low and the curvature of the contact line becomes large, is also investigated.

  10. Geomorphological and hydrological implications of a given hydraulic geometry relationship, beyond the power-law

    Science.gov (United States)

    Kim, JongChun; Paik, Kyungrock

    2015-04-01

    Channel geometry and hydraulic characteristics of a given river network, i.e., spatio-temporal variability of width, depth, and velocity, can be described as power functional relationships of flow discharge, named 'hydraulic geometry' (Leopold and Maddock, 1953). Many studies have focused on the implication of this power-law itself, i.e., self-similarity, and accordingly its exponents. Coefficients of the power functional relationships, on the contrary, have received little attention. They are often regarded as empirical constants, determined by 'best fitting' to the power-law without significant scientific implications. Here, we investigate and claim that power-law coefficients of hydraulic geometry relationships carry vital information of a given river system. We approach the given problem on the basis of 'basin hydraulic geometry' formulation (Stall and Fok, 1968) which decomposes power-law coefficients into more elementary constants. The linkage between classical power-law relationship (Leopold and Maddock, 1953) and the basin hydraulic geometry is provided by Paik and Kumar (2004). On the basis of this earlier study, it can be shown that coefficients and exponents of power-law hydraulic geometry are interrelated. In this sense, we argue that more elementary constants that constitute both exponents and coefficients carry important messages. In this presentation, we will demonstrate how these elementary constants vary over a wide range of catchments provided from Stall and Fok (1968) and Stall and Yang (1970). Findings of this study can provide new insights on fundamental understanding about hydraulic geometry relationships. Further, we expect that this understanding can help interpretation of hydraulic geometry relationship in the context of flood propagation through a river system as well. Keywords: Hydraulic geometry; Power-law; River network References Leopold, L. B., & Maddock, T. J. (1953). The hydraulic geometry of stream channels and some physiographic

  11. Hydrodynamics-based functional forms of activity metabolism: a case for the power-law polynomial function in animal swimming energetics.

    Science.gov (United States)

    Papadopoulos, Anthony

    2009-01-01

    The first-degree power-law polynomial function is frequently used to describe activity metabolism for steady swimming animals. This function has been used in hydrodynamics-based metabolic studies to evaluate important parameters of energetic costs, such as the standard metabolic rate and the drag power indices. In theory, however, the power-law polynomial function of any degree greater than one can be used to describe activity metabolism for steady swimming animals. In fact, activity metabolism has been described by the conventional exponential function and the cubic polynomial function, although only the power-law polynomial function models drag power since it conforms to hydrodynamic laws. Consequently, the first-degree power-law polynomial function yields incorrect parameter values of energetic costs if activity metabolism is governed by the power-law polynomial function of any degree greater than one. This issue is important in bioenergetics because correct comparisons of energetic costs among different steady swimming animals cannot be made unless the degree of the power-law polynomial function derives from activity metabolism. In other words, a hydrodynamics-based functional form of activity metabolism is a power-law polynomial function of any degree greater than or equal to one. Therefore, the degree of the power-law polynomial function should be treated as a parameter, not as a constant. This new treatment not only conforms to hydrodynamic laws, but also ensures correct comparisons of energetic costs among different steady swimming animals. Furthermore, the exponential power-law function, which is a new hydrodynamics-based functional form of activity metabolism, is a special case of the power-law polynomial function. Hence, the link between the hydrodynamics of steady swimming and the exponential-based metabolic model is defined.

  12. Hydrodynamics-based functional forms of activity metabolism: a case for the power-law polynomial function in animal swimming energetics.

    Directory of Open Access Journals (Sweden)

    Anthony Papadopoulos

    Full Text Available The first-degree power-law polynomial function is frequently used to describe activity metabolism for steady swimming animals. This function has been used in hydrodynamics-based metabolic studies to evaluate important parameters of energetic costs, such as the standard metabolic rate and the drag power indices. In theory, however, the power-law polynomial function of any degree greater than one can be used to describe activity metabolism for steady swimming animals. In fact, activity metabolism has been described by the conventional exponential function and the cubic polynomial function, although only the power-law polynomial function models drag power since it conforms to hydrodynamic laws. Consequently, the first-degree power-law polynomial function yields incorrect parameter values of energetic costs if activity metabolism is governed by the power-law polynomial function of any degree greater than one. This issue is important in bioenergetics because correct comparisons of energetic costs among different steady swimming animals cannot be made unless the degree of the power-law polynomial function derives from activity metabolism. In other words, a hydrodynamics-based functional form of activity metabolism is a power-law polynomial function of any degree greater than or equal to one. Therefore, the degree of the power-law polynomial function should be treated as a parameter, not as a constant. This new treatment not only conforms to hydrodynamic laws, but also ensures correct comparisons of energetic costs among different steady swimming animals. Furthermore, the exponential power-law function, which is a new hydrodynamics-based functional form of activity metabolism, is a special case of the power-law polynomial function. Hence, the link between the hydrodynamics of steady swimming and the exponential-based metabolic model is defined.

  13. Fractal approach towards power-law coherency to measure cross-correlations between time series

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2017-01-01

    Roč. 50, č. 1 (2017), s. 193-200 ISSN 1007-5704 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : power- law coherency * power- law cross-correlations * correlations Subject RIV: AH - Economics OBOR OECD: Applied Economics, Econometrics Impact factor: 2.784, year: 2016 http://library.utia.cas.cz/separaty/2017/E/kristoufek-0473066.pdf

  14. Characterising rock fracture aperture-spacing relationships using power-law relationships: some considerations

    Science.gov (United States)

    Brook, Martin; Hebblewhite, Bruce; Mitra, Rudrajit

    2016-04-01

    The size-scaling of rock fractures is a well-studied problem in geology, especially for permeability quantification. The intensity of fractures may control the economic exploitation of fractured reservoirs because fracture intensity describes the abundance of fractures potentially available for fluid flow. Moreover, in geotechnical engineering, fractures are important for parameterisation of stress models and excavation design. As fracture data is often collected from widely-spaced boreholes where core recovery is often incomplete, accurate interpretation and representation of fracture aperture-frequency relationships from sparse datasets is important. Fracture intensity is the number of fractures encountered per unit length along a sample scanline oriented perpendicular to the fractures in a set. Cumulative frequency of fractures (F) is commonly related to fracture aperture (A) in the form of a power-law (F = aA-b), with variations in the size of the a coefficient between sites interpreted to equate to fracture frequency for a given aperture (A). However, a common flaw in this approach is that even a small change in b can have a large effect on the response of the fracture frequency (F) parameter. We compare fracture data from the Late Permian Rangal Coal Measures from Australia's Bowen Basin, with fracture data from Jurassic carbonates from the Sierra Madre Oriental, northeastern Mexico. Both power-law coefficient a and exponent b control the fracture aperture-frequency relationship in conjunction with each other; that is, power-laws with relatively low a coefficients have relatively high b exponents and vice versa. Hence, any comparison of different power-laws must take both a and b into consideration. The corollary is that different sedimentary beds in the Sierra Madre carbonates do not show ˜8× the fracture frequency for a given fracture aperture, as based solely on the comparison of coefficient a. Rather, power-law "sensitivity factors" developed from both

  15. High-power LED light sources for optical measurement systems operated in continuous and overdriven pulsed modes

    Science.gov (United States)

    Stasicki, Bolesław; Schröder, Andreas; Boden, Fritz; Ludwikowski, Krzysztof

    2017-06-01

    The rapid progress of light emitting diode (LED) technology has recently resulted in the availability of high power devices with unprecedented light emission intensities comparable to those of visible laser light sources. On this basis two versatile devices have been developed, constructed and tested. The first one is a high-power, single-LED illuminator equipped with exchangeable projection lenses providing a homogenous light spot of defined diameter. The second device is a multi-LED illuminator array consisting of a number of high-power LEDs, each integrated with a separate collimating lens. These devices can emit R, G, CG, B, UV or white light and can be operated in pulsed or continuous wave (CW) mode. Using an external trigger signal they can be easily synchronized with cameras or other devices. The mode of operation and all parameters can be controlled by software. Various experiments have shown that these devices have become a versatile and competitive alternative to laser and xenon lamp based light sources. The principle, design, achieved performances and application examples are given in this paper.

  16. Anisotropic power-law inflation for a conformal-violating Maxwell model

    Science.gov (United States)

    Do, Tuan Q.; Kao, W. F.

    2018-05-01

    A set of power-law solutions of a conformal-violating Maxwell model with a non-standard scalar-vector coupling will be shown in this paper. In particular, we are interested in a coupling term of the form X^{2n} F^{μ ν }F_{μ ν } with X denoting the kinetic term of the scalar field. Stability analysis indicates that the new set of anisotropic power-law solutions is unstable during the inflationary phase. The result is consistent with the cosmic no-hair conjecture. We show, however, that a set of stable slowly expanding solutions does exist for a small range of parameters λ and n. Hence a small anisotropy can survive during the slowly expanding phase.

  17. Power-law connections: From Zipf to Heaps and beyond

    International Nuclear Information System (INIS)

    Eliazar, Iddo I.; Cohen, Morrel H.

    2013-01-01

    In this paper we explore the asymptotic statistics of a general model of rank distributions in the large-ensemble limit; the construction of the general model is motivated by recent empirical studies of rank distributions. Applying Lorenzian, oligarchic, and Heapsian asymptotic analyses we establish a comprehensive set of closed-form results linking together rank distributions, probability distributions, oligarchy sizes, and innovation rates. In particular, the general results reveal the fundamental underlying connections between Zipf’s law, Pareto’s law, and Heaps’ law—three elemental empirical power-laws that are ubiquitously observed in the sciences. -- Highlights: ► The large-ensemble asymptotic statistics of rank distributions are explored. ► Lorenzian, oligarchic, and Heapsian asymptotic analyses are applied. ► Associated oligarchy sizes and induced innovation rates are analyzed. ► General elemental statistical connections are established. ► The underlying connections between Zipf’s, Pareto’s and Heaps’ laws are unveiled

  18. Tachyon with an inverse power-law potential in a braneworld cosmology

    Science.gov (United States)

    Bilić, Neven; Domazet, Silvije; Djordjevic, Goran S.

    2017-08-01

    We study a tachyon cosmological model based on the dynamics of a 3-brane in the bulk of the second Randall-Sundrum model extended to more general warp functions. A well known prototype of such a generalization is the bulk with a selfinteracting scalar field. As a consequence of a generalized bulk geometry the cosmology on the observer brane is modified by the scale dependent four-dimensional gravitational constant. In particular, we study a power law warp factor which generates an inverse power-law potential V\\propto \\varphi-n of the tachyon field φ. We find a critical power n cr that divides two subclasses with distinct asymptotic behaviors: a dust universe for n>n_cr and a quasi de Sitter universe for 0.

  19. Power law for the duration of recession and prosperity in Latin American countries

    Science.gov (United States)

    Redelico, Francisco O.; Proto, Araceli N.; Ausloos, Marcel

    2008-11-01

    Ormerod and Mounfield [P. Ormerod, C. Mounfield, Power law distribution of duration and magnitude of recessions in capitalist economies: Breakdown of scaling, Physica A 293 (2001) 573] and Ausloos et al. [M. Ausloos, J. Mikiewicz, M. Sanglier, The durations of recession and prosperity: Does their distribution follow a power or an exponential law? Physica A 339 (2004) 548] have independently analyzed the duration of recessions for developed countries through the evolution of the GDP in different time windows. It was found that there is a power law governing the duration distribution. We have analyzed data collected from 19 Latin American countries in order to observe whether such results are valid or not for developing countries. The case of prosperity years is also discussed. We observe that the power law of recession time intervals, see Ref. [1], is valid for Latin American countries as well. Thus an interesting point is discovered: the same scaling time is found in the case of recessions for the three data sets (ca. 1 year), and this could represent a universal feature. Other time scale parameters differ significantly from each other.

  20. Power laws and elastic nonlinearity in materials with complex microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Scalerandi, M., E-mail: marco.scalerandi@infm.polito.it

    2016-01-28

    Nonlinear ultrasonic methods have been widely used to characterize the microstructure of damaged solids and consolidated granular media. Besides distinguishing between materials exhibiting classical nonlinear behaviors from those exhibiting hysteresis, it could be of importance the discrimination between ultrasonic indications from different physical sources (scatterers). Elastic hysteresis could indeed be due to dislocations, grain boundaries, stick-slip at interfaces, etc. Analyzing data obtained on various concrete samples, we show that the power law behavior of the nonlinear indicator vs. the energy of excitation could be used to classify different microscopic features. In particular, the power law exponent ranges between 1 and 3, depending on the nature of nonlinearity. We also provide a theoretical interpretation of the collected data using models for clapping and hysteretic nonlinearities. - Highlights: • Several materials exhibit a nontrivial nonlinear elastic behavior which can be ascribed to different physical sources. • The quantitative nonlinear response is dependent on the type of microstructure present in the material. • A nonlinear indicator could be defined which depends on the excitation energy of the sample. • Assuming a power law dependence, the exponent depends on the microstructure of the material and could evolve in time. • Experimental results on concrete are discussed and a theoretical description is proposed.

  1. Isomorphs in the phase diagram of a model liquid without inverse power law repulsion

    DEFF Research Database (Denmark)

    Veldhorst, Arnold Adriaan; Bøhling, Lasse; Dyre, J. C.

    2012-01-01

    scattering function are calculated. The results are shown to reflect a hidden scale invariance; despite its exponential repulsion the Buckingham potential is well approximated by an inverse power-law plus a linear term in the region of the first peak of the radial distribution function. As a consequence...... the dynamics of the viscous Buckingham liquid is mimicked by a corresponding model with purely repulsive inverse-power-law interactions. The results presented here closely resemble earlier results for Lennard-Jones type liquids, demonstrating that the existence of strong correlations and isomorphs does...... not depend critically on the mathematical form of the repulsion being an inverse power law....

  2. Power-law modulation of the scalar power spectrum from a heavy field with a monomial potential

    Science.gov (United States)

    Huang, Qing-Guo; Pi, Shi

    2018-04-01

    The effects of heavy fields modulate the scalar power spectrum during inflation. We analytically calculate the modulations of the scalar power spectrum from a heavy field with a separable monomial potential, i.e. V(phi)~ phin. In general the modulation is characterized by a power-law oscillation which is reduced to the logarithmic oscillation in the case of n=2.

  3. The enforcement order for the law for arrangement of surrounding areas of power generating facilities

    International Nuclear Information System (INIS)

    1980-01-01

    This rule is established under the provisions of the law for the redevelopment of the surrounding areas of power generating facilities. Persons who install power generating facilities under the law include general electric power enterprises and wholesale electric power enterprises defined under the electric enterprises act and the Power Reactor and Nuclear Fuel Development Corporation. The scale of these facilities defined under the law is 350,000 kilo-watts output for atomic and thermal power generating facilities, 10,000 kilo-watts output for the facilities utilizing geothermal energy, 100,000 kilo-watts output for facilities whose main fuel is coal, and 1,000 kilo-watts output for hydraulic power generating facilities, etc. The facilities closely related to atomic power generation include the reprocessing and examination facilities of fuel materials spent in atomic power reactors, the reactors installed by the Japan Atomic Energy Research Institute for studying on the safety of atomic power reactors, the experimental fast reactors and the uranium enrichment facilities established by the Power Reactor and Nuclear Fuel Development Corporation. The public facilities in this rule are those for communication, sport and recreation, environment hygiene, education and culture, medicine, social welfare, fire fighting, etc. Governors of prefectures who intend to get approval under the law shall file redevelopment plans to the competent minister through the Minister of the International Trade and Industry. (Okada, K.)

  4. Macro impact of the law on prevention and control of atmospheric pollution on power industry development

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z. [State Power Corporation (China). Dept. of Science, Technology and Environment

    2001-07-01

    The newly revised and enlarged main contents of China's Law of Prevention and Control of Atmospheric Pollution, which came into force on 1 September 2000, are described. The macro impacts of the law on the power industry development are analyzed mainly in respect to power demand and readjustment of power structure and layout, clean production and pollution control level, scientific management of environmental protection, in accordance with law as well as changes of construction and operation costs. Several questions worthy to be noted in course of implementation of the new law are enumerated. 1 tab.

  5. Explaining the power-law distribution of human mobility through transportation modality decomposition

    Science.gov (United States)

    Zhao, Kai; Musolesi, Mirco; Hui, Pan; Rao, Weixiong; Tarkoma, Sasu

    2015-03-01

    Human mobility has been empirically observed to exhibit Lévy flight characteristics and behaviour with power-law distributed jump size. The fundamental mechanisms behind this behaviour has not yet been fully explained. In this paper, we propose to explain the Lévy walk behaviour observed in human mobility patterns by decomposing them into different classes according to the different transportation modes, such as Walk/Run, Bike, Train/Subway or Car/Taxi/Bus. Our analysis is based on two real-life GPS datasets containing approximately 10 and 20 million GPS samples with transportation mode information. We show that human mobility can be modelled as a mixture of different transportation modes, and that these single movement patterns can be approximated by a lognormal distribution rather than a power-law distribution. Then, we demonstrate that the mixture of the decomposed lognormal flight distributions associated with each modality is a power-law distribution, providing an explanation to the emergence of Lévy Walk patterns that characterize human mobility patterns.

  6. A study on the sensitivity depletion laws for rhodium self-powered neutron detectors

    International Nuclear Information System (INIS)

    Kim, Gil Gon

    1999-02-01

    The rhodium self-powered neutron detectors (SPND) in a reactor core provide the operator with the on-line 3-dimensional nuclear power distribution. The signal produced by rhodium SPND is interpreted into the local neutron flux by using a sensitivity depletion law and the local neutron flux is interpreted into the local power by using a power conversion factor. This work on the sensitivity depletion laws for rhodium self-powered neutron detectors (SPND) is performed to improve the uncertainty of the sensitivity depletion law used in ABB-CE reactors employing a rhodium SPND and to develop a calculational tool for providing the sensitivity depletion laws to interpret the signal of the newly designed rhodium SPND into the local neutron flux. The calculational tools for a time dependent neutron flux distribution in the rhodium emitter during depletion and for a time dependent beta escape probability that a beta generated in the emitter is escaped into the collector were developed. Due to the cost, the exposure to the radiation, and the longer fuel cycle, there is a strong incentive that the loading density of an in-core instrumentation is reduced and the lifetime of the detector is lengthened. These objectives can be achieved by reducing the uncertainty which is amplified as it depletes. The calculational tools above provide the sensitivity depletion law and show the reduction of the uncertainty to about 1 % in interpreting the signal into the local neutron flux compared to the method employed by ABB-CE. The reduction in the uncertainty of 1 % in interpreting the signal into the local neutron flux is equivalent to the reduction in the uncertainty of 1 % or more in interpreting the signal into the local power and to the extension of the lifetime of rhodium SPND to about 10 % as reported by ABB-CE

  7. Non-power law behavior of the radial profile of phase-space density of halos

    International Nuclear Information System (INIS)

    Popolo, A. Del

    2011-01-01

    We study the pseudo phase-space density, ρ(r)/σ 3 (r), of ΛCDM dark matter halos with and without baryons (baryons+DM, and pure DM), by using the model introduced in Del Popolo (2009), which takes into account the effect of dynamical friction, ordered and random angular momentum, baryons adiabatic contraction and dark matter baryons interplay. We examine the radial dependence of ρ(r)/σ 3 (r) over 9 orders of magnitude in radius for structures on galactic and cluster of galaxies scales. We find that ρ(r)/σ 3 (r) is approximately a power-law only in the range of halo radius resolved by current simulations (down to 0.1% of the virial radius) while it has a non-power law behavior below the quoted scale, with inner profiles changing with mass. The non-power-law behavior is more evident for halos constituted both of dark matter and baryons while halos constituted just of dark matter and with angular momentum chosen to reproduce a Navarro-Frenk-White (NFW) density profile, are characterized by an approximately power-law behavior. The results of the present paper lead to conclude that density profiles of the NFW type are compatible with a power-law behavior of ρ(r)/σ 3 (r), while those flattening to the halo center, like those found in Del Popolo (2009) or the Einasto profile, or the Burkert profile, cannot produce radial profile of the pseudo-phase-space density that are power-laws at all radii. The results argue against universality of the pseudo phase-space density and as a consequence argue against universality of density profiles constituted by dark matter and baryons as also discussed in Del Popolo (2009)

  8. How Power-Laws Re-Write The Rules Of Cyber Warfare

    Directory of Open Access Journals (Sweden)

    David L. Bibighaus

    2015-12-01

    Full Text Available All warfare contains and element of randomness. This article will argue that, the kind uncertainty encountered in cyber warfare (Power-Law randomness is fundamentally different from the uncertainty the military has evolved to deal with in the physical world (Gaussian-Randomness. The article will explain the difference between these two kinds of randomness, and how cyber weapons appear to operate under Power-Law randomness. It then will show how in cyberspace, key aspects of strategic thought are based on a flaws assumption of randomness. Finally, this article shall argue that if the American military is going to be effective in cyberspace, it must re-examine the way the military assumes risk, recruits is forces, plans for war and maintains the peace.

  9. Fall Velocities of Hydrometeors in the Atmosphere: Refinements to a Continuous Analytical Power Law.

    Science.gov (United States)

    Khvorostyanov, Vitaly I.; Curry, Judith A.

    2005-12-01

    This paper extends the previous research of the authors on the unified representation of fall velocities for both liquid and crystalline particles as a power law over the entire size range of hydrometeors observed in the atmosphere. The power-law coefficients are determined as continuous analytical functions of the Best or Reynolds number or of the particle size. Here, analytical expressions are formulated for the turbulent corrections to the Reynolds number and to the power-law coefficients that describe the continuous transition from the laminar to the turbulent flow around a falling particle. A simple analytical expression is found for the correction of fall velocities for temperature and pressure. These expressions and the resulting fall velocities are compared with observations and other calculations for a range of ice crystal habits and sizes. This approach provides a continuous analytical power-law description of the terminal velocities of liquid and crystalline hydrometeors with sufficiently high accuracy and can be directly used in bin-resolving models or incorporated into parameterizations for cloud- and large-scale models and remote sensing techniques.

  10. Power law deformation of Wishart–Laguerre ensembles of random matrices

    International Nuclear Information System (INIS)

    Akemann, Gernot; Vivo, Pierpaolo

    2008-01-01

    We introduce a one-parameter deformation of the Wishart–Laguerre or chiral ensembles of positive definite random matrices with Dyson index β = 1,2 and 4. Our generalized model has a fat-tailed distribution while preserving the invariance under orthogonal, unitary or symplectic transformations. The spectral properties are derived analytically for finite matrix size N × M for all three values of β, in terms of the orthogonal polynomials of the standard Wishart–Laguerre ensembles. For large N in a certain double-scaling limit we obtain a generalized Marčenko–Pastur distribution on the macroscopic scale, and a generalized Bessel law at the hard edge which is shown to be universal. Both macroscopic and microscopic correlations exhibit power law tails, where the microscopic limit depends on β and the difference M−N. In the limit where our parameter governing the power law goes to infinity we recover the correlations of the Wishart–Laguerre ensembles. To illustrate these findings, the generalized Marčenko–Pastur distribution is shown to be in very good agreement with empirical data from financial covariance matrices

  11. A Note on the Invariance Properties and Conservation Laws of the Kadomstev—Petviashvili Equation with Power Law Nonlinearity

    International Nuclear Information System (INIS)

    Bokhari A H; Zaman F D; Fakhar K; Kara A H

    2011-01-01

    First, we studied the invariance properties of the Kadomstev—Petviashvili equation with power law nonlinearity. Then, we determined the complete class of conservation laws and stated the corresponding conserved densities which are useful in finding the conserved quantities of the equation. The point symmetry generators were also used to reduce the equation to an exact solution and to verify the invariance properties of the conserved flows. (general)

  12. Problems and legislative remedies of the parallel law systems in Japan for nuclear power reactors

    International Nuclear Information System (INIS)

    Irie, Kazutomo

    2011-01-01

    There are two established laws governing nuclear power reactors in Japan. One is the Electricity Utilities Industry Law, which regulates the nuclear power reactors, and the other is the so-called 'Reactor Regulation Law', which dually regulates the reactors in some phases. When a graded approach on the regulation of nuclear reactors was adopted, it extended over these two laws and was legislatively imperfect. Such imperfection created problems from the beginning. Also, the original regulatory structures presented by these laws had become obscure during the operation process of the graded regulation. The situation becomes further complicated by the revision of these laws in recent years. It appears that the trait of the regulatory procedural structure of the Electricity Utilities Industry Law has been weakened. As there is a pressing need to review the entire regulatory structure and to propose a unified regulatory system by combining these laws, this paper examines the merits and demerits of combining these laws under a unified regulation. (author)

  13. Power-law cross-correlations estimation under heavy tails

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2016-01-01

    Roč. 40, č. 1 (2016), s. 163-172 ISSN 1007-5704 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : Power-law cross-correlations * Heavy tails * Monte Carlo study Subject RIV: AH - Economics Impact factor: 2.784, year: 2016 http://library.utia.cas.cz/separaty/2016/E/kristoufek-0472030.pdf

  14. Power laws and inverse motion modelling: application to turbulence measurements from satellite images

    Directory of Open Access Journals (Sweden)

    Pablo D. Mininni

    2012-01-01

    Full Text Available In the context of tackling the ill-posed inverse problem of motion estimation from image sequences, we propose to introduce prior knowledge on flow regularity given by turbulence statistical models. Prior regularity is formalised using turbulence power laws describing statistically self-similar structure of motion increments across scales. The motion estimation method minimises the error of an image observation model while constraining second-order structure function to behave as a power law within a prescribed range. Thanks to a Bayesian modelling framework, the motion estimation method is able to jointly infer the most likely power law directly from image data. The method is assessed on velocity fields of 2-D or quasi-2-D flows. Estimation accuracy is first evaluated on a synthetic image sequence of homogeneous and isotropic 2-D turbulence. Results obtained with the approach based on physics of fluids outperform state-of-the-art. Then, the method analyses atmospheric turbulence using a real meteorological image sequence. Selecting the most likely power law model enables the recovery of physical quantities, which are of major interest for turbulence atmospheric characterisation. In particular, from meteorological images we are able to estimate energy and enstrophy fluxes of turbulent cascades, which are in agreement with previous in situ measurements.

  15. The rate coefficients of unimolecular reactions in the systems with power-law distributions

    Science.gov (United States)

    Yin, Cangtao; Guo, Ran; Du, Jiulin

    2014-08-01

    The rate coefficient formulae of unimolecular reactions are generalized to the systems with the power-law distributions based on nonextensive statistics, and the power-law rate coefficients are derived in the high and low pressure limits, respectively. The numerical analyses are made of the rate coefficients as functions of the ν-parameter, the threshold energy, the temperature and the number of degrees of freedom. We show that the new rate coefficients depend strongly on the ν-parameter different from one (thus from a Boltzmann-Gibbs distribution). Two unimolecular reactions, CH3CO→CH3+CO and CH3NC→CH3CN, are taken as application examples to calculate their power-law rate coefficients, which obtained with the ν-parameters slightly different from one can be exactly in agreement with all the experimental studies on these two reactions in the given temperature ranges.

  16. Extremal dependencies and rank correlations in power law networks

    NARCIS (Netherlands)

    Volkovich, Y.; Litvak, Nelli; Zwart, B.; Jie, Z.

    2009-01-01

    We analyze dependencies in complex networks characterized by power laws (Web sample, Wikipedia sample and a preferential attachment graph) using statistical techniques from the extreme value theory and the theory of multivariate regular variation. To the best of our knowledge, this is the first

  17. Sharing Powers Within Exclusive Competences: Rethinking EU Antitrust Law Enforcement

    OpenAIRE

    Van Cleynenbreugel, Pieter

    2016-01-01

    Although the establishment of competition rules forms part of the EU’s exclusive competences, the application and enforcement of those rules has always been shared consistently between the EU and its Member States.The sharing of enforcement powers is conceptualised traditionally as a delegation of the exercise of exclusively conferred competences. The Court of Justice of the European Union’s case law in the context of EU antitrust law enforcement nevertheless raises profound questions as to t...

  18. The mean first passage time in an energy-diffusion controlled regime with power-law distributions

    International Nuclear Information System (INIS)

    Zhou, Yanjun; Du, Jiulin

    2013-01-01

    Based on the mean first passage time (MFPT) theory, we derive an expression of the MFPT in an energy-diffusion controlled regime with a power-law distribution. We discuss the finite barrier effect (i.e. the thermal energy k B T is not small with respect to the potential barrier E b ) and compare it with Kramers’ infinite barrier result both in a power-law distribution and in a Maxwell–Boltzmann distribution. It is shown that the MFPT with a power-law distribution extends Kramers’ low-damping result to a relatively low barrier. We pay attention to the energy-diffusion controlled regime, which is of great interest in the context of Josephson junctions, and study how the power-law parameter κ affects the current distribution function in experiments with Josephson junctions. (paper)

  19. The Legal Regime of Nuclear Power Satellites-A Problem at the Cross-Roads of Nuclear Law and Space Law

    International Nuclear Information System (INIS)

    Courteix, S.

    1992-01-01

    The number of nuclear-powered satellites rises constantly and, recalling the fear generated by the crash of the Cosmos 954 satellite, the author points out that radioactive debris falling on earth could represent as great a hazard as accidental releases of radioactive material from land-based nuclear installations. Such satellites, therefore, can be governed by both space law and nuclear law. On the basis of international conventions applicable in the two fields and also with reference to the Law of the Sea and environmental law, the article analyses preventive and radiation protection measures as well as emergency plans and also raises the problem of liability and compensation for damage. (NEA)

  20. Offshore wind power system in the Exclusive Economic Zone. Applicability of German property law; Offshore-Windenergieanlagen in der AWZ. Anwendbarkeit des deutschen Sachenrechts

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Thomas; Glaesner, Michael [Linklaters LLP, Berlin (Germany)

    2013-04-15

    The present article shows how a lack of regulation has led to a certain degree of legal uncertainty as to whether offshore wind power plants located in the German Exclusive Economic Zone are amenable to German property law. For practical purposes this has made it necessary to negotiate project contracts such that the transfer of ownership of individual components is effected while these are still on shore, even if the purchase price has yet to be fully paid. The financing banks have a policy in place of demanding the establishment of a subsidiary which is to receive ownership of the assets. This makes the structure of such contracts a great deal more complicated in terms of corporations law and tax law. The present article summarises the experiences gained by lawyers in these matters, giving an overview of the different legal positions taken on them to date. It shows that the applicability of German property law follows from the law now in force. Aside from this the authors advocate amendments to the relevant IPR norm as a means of reinforcing legal certainty in practice and make a concrete proposal for a clause to this end.

  1. Legal basis of energy economy. Collection of important laws and regulations of the amended power economy law. 7. ed.; Rechtsgrundlagen der Energiewirtschaft. Sammlung wichtiger Gesetze und Vorschriften zum novellierten Energiewirtschaftsrecht

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, B.J.; Schweers, E.

    2007-07-01

    The book under consideration is an actual collection of important laws and regulations according to the amended power economy law. It is the 7th edition and contains components of the European and national cartel law. Furthermore, the power economy law, the regulations of mains access, and the regulations of mains fee are revised editorial. The book consist of four main chapters: (a) General energy law; (b) Bylaws to energy economical laws; (c) Law of privileged energy supports; (d) cartel law.

  2. Power-law cosmic expansion in f(R) gravity models

    International Nuclear Information System (INIS)

    Goheer, Naureen; Larena, Julien; Dunsby, Peter K. S.

    2009-01-01

    We show that within the class of f(R) gravity theories, Friedmann-Lemaitre-Robertson-Walker power-law perfect fluid solutions only exist for R n gravity. This significantly restricts the set of exact cosmological solutions which have similar properties to what is found in standard general relativity.

  3. On heat transfer of weakly compressible power-law flows

    Directory of Open Access Journals (Sweden)

    Li Botong

    2017-01-01

    Full Text Available This paper completes a numerical research on steady momentum and heat transfer in power-law fluids in a channel. Weakly compressible laminar fluids are studied with no slip at the walls and uniform wall temperatures. The full governing equations are solved by continuous finite element method. Three thermal conductivity models are adopted in this paper, that is, constant thermal conductivity model, thermal conductivity varying as a function of temperature gradient, and a modified temperature-gradient-dependent thermal conductivity model. The results are compared with each other and the physical characteristics for values of parameters are also discussed in details. It is shown that the velocity curve from the solution becomes straight at higher power-law index. The effects of Reynolds numbers on the dilatant fluid and the pseudo-plastic look similar to each other and their trends can be easily predicted. Furthermore, for different models, the temperature curves also present pseudo-plastic and dilatant properties.

  4. Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Poplawski, Michael E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Brown, Charles C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    To date, all three reports in the retail lamps series have focused on basic performance parameters, such as lumen output, efficacy, and color quality. This report goes a step further, examining the photoelectric characteristics (i.e., dimming and flicker) of a subset of lamps from CALiPER Retails Lamps Study 3. Specifically, this report focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers. The results demonstrate notable variation across the various lamps, but little variation between the four dimmers. Overall, the LED lamps: ~tended to have higher relative light output compared to the incandescent and halogen benchmark at the same dimmer output signal (RMS voltage). The lamps’ dimming curves (i.e., the relationship between control signal and relative light output) ranged from linear to very similar to the square-law curve typical of an incandescent lamp. ~generally exhibited symmetrical behavior—the same dimming curve—when measured proceeding from maximum to minimum or minimum to maximum control signal. ~mostly dimmed below 10% of full light output, with some exceptions for specific lamp and dimmer combinations ~exhibited a range of flicker characteristics, with many comparing favorably to the level typical of a magnetically-ballasted fluorescent lamp through at least a majority of the dimming range. ~ always exceeded the relative (normalized) efficacy over the dimming range of the benchmark lamps, which rapidly decline in efficacy when they are dimmed. This report generally does not attempt to rank the performance of one product compared to another, but instead focuses on the collective performance of the group versus conventional incandescent or halogen lamps, the performance of which is likely to be the baseline for a majority of consumers. Undoubtedly, some LED lamps perform better—or more similar to conventional lamps—than others. Some perform desirably for one

  5. Discovery of Power-Law Growth in the Self-Renewal of Heterogeneous Glioma Stem Cell Populations.

    Directory of Open Access Journals (Sweden)

    Michiya Sugimori

    Full Text Available Accumulating evidence indicates that cancer stem cells (CSCs drive tumorigenesis. This suggests that CSCs should make ideal therapeutic targets. However, because CSC populations in tumors appear heterogeneous, it remains unclear how CSCs might be effectively targeted. To investigate the mechanisms by which CSC populations maintain heterogeneity during self-renewal, we established a glioma sphere (GS forming model, to generate a population in which glioma stem cells (GSCs become enriched. We hypothesized, based on the clonal evolution concept, that with each passage in culture, heterogeneous clonal sublines of GSs are generated that progressively show increased proliferative ability.To test this hypothesis, we determined whether, with each passage, glioma neurosphere culture generated from four different glioma cell lines become progressively proliferative (i.e., enriched in large spheres. Rather than monitoring self-renewal, we measured heterogeneity based on neurosphere clone sizes (#cells/clone. Log-log plots of distributions of clone sizes yielded a good fit (r>0.90 to a straight line (log(% total clones = k*log(#cells/clone indicating that the system follows a power-law (y = xk with a specific degree exponent (k = -1.42. Repeated passaging of the total GS population showed that the same power-law was maintained over six passages (CV = -1.01 to -1.17. Surprisingly, passage of either isolated small or large subclones generated fully heterogeneous populations that retained the original power-law-dependent heterogeneity. The anti-GSC agent Temozolomide, which is well known as a standard therapy for glioblastoma multiforme (GBM, suppressed the self-renewal of clones, but it never disrupted the power-law behavior of a GS population.Although the data above did not support the stated hypothesis, they did strongly suggest a novel mechanism that underlies CSC heterogeneity. They indicate that power-law growth governs the self-renewal of heterogeneous

  6. High power light emitting diode (LED) arrays versus halogen light polymerization of oral biomaterials: Barcol hardness, compressive strength and radiometric properties.

    Science.gov (United States)

    Mills, Robin W; Uhl, Alexander; Blackwell, Gordon B; Jandt, Klaus D

    2002-07-01

    The clinical performance of light polymerized dental composites is greatly influenced by the quality of the light curing unit (LCU) used. Commonly used halogen LCUs have some specific drawbacks such as decreasing light output with time. This may result in a low degree of monomer conversion of the composites with negative clinical implications. Previous studies have shown that blue light emitting diode (LED) LCUs have the potential to polymerize dental composites without having the drawbacks of halogen LCUs. Since these studies were carried out LED technology has advanced significantly and commercial LED LCUs are now becoming available. This study investigates the Barcol hardness as a function of depth, and the compressive strength of dental composites that had been polymerized for 40 or 20s with two high power LED LCU prototypes, a commercial LED LCU, and a commercial halogen LCU. In addition the radiometric properties of the LCUs were characterized. The two high power prototype LED LCUs and the halogen LCU showed a satisfactory and similar hardness-depth performance whereas the hardness of the materials polymerized with the commercial LED LCU rapidly decreased with sample depth and reduced polymerization time (20 s). There were statistically significant differences in the overall compressive strengths of composites polymerized with different LCUs at the 95% significance level (p = 0.0016) with the two high power LED LCU prototypes and the halogen LCU forming a statistically homogenous group. In conclusion, LED LCU polymerization technology can reach the performance level of halogen LCUs. One of the first commercial LED LCUs however lacked the power reserves of the high power LED LCU prototypes.

  7. Modelling reverse characteristics of power LEDs with thermal phenomena taken into account

    International Nuclear Information System (INIS)

    Ptak, Przemysław; Górecki, Krzysztof

    2016-01-01

    This paper refers to modelling characteristics of power LEDs with a particular reference to thermal phenomena. Special attention is paid to modelling characteristics of the circuit protecting the considered device against the excessive value of the reverse voltage and to the description of the temperature influence on optical power. The network form of the worked out model is presented and some results of experimental verification of this model for the selected diodes operating at different cooling conditions are described. The very good agreement between the calculated and measured characteristics is obtained

  8. The Power Laws of Violence against Women: Rescaling Research and Policies

    Science.gov (United States)

    Kappler, Karolin E.; Kaltenbrunner, Andreas

    2012-01-01

    Background Violence against Women –despite its perpetuation over centuries and its omnipresence at all social levels– entered into social consciousness and the general agenda of Social Sciences only recently, mainly thanks to feminist research, campaigns, and general social awareness. The present article analyzes in a secondary analysis of German prevalence data on Violence against Women, whether the frequency and severity of Violence against Women can be described with power laws. Principal Findings Although the investigated distributions all resemble power-law distributions, a rigorous statistical analysis accepts this hypothesis at a significance level of 0.1 only for 1 of 5 cases of the tested frequency distributions and with some restrictions for the severity of physical violence. Lowering the significance level to 0.01 leads to the acceptance of the power-law hypothesis in 2 of the 5 tested frequency distributions and as well for the severity of domestic violence. The rejections might be mainly due to the noise in the data, with biases caused by self-reporting, errors through rounding, desirability response bias, and selection bias. Conclusion Future victimological surveys should be designed explicitly to avoid these deficiencies in the data to be able to clearly answer the question whether Violence against Women follows a power-law pattern. This finding would not only have statistical implications for the processing and presentation of the data, but also groundbreaking consequences on the general understanding of Violence against Women and policy modeling, as the skewed nature of the underlying distributions makes evident that Violence against Women is a highly disparate and unequal social problem. This opens new questions for interdisciplinary research, regarding the interplay between environmental, experimental, and social factors on victimization. PMID:22768348

  9. Self-Excited Single-Stage Power Factor Correction Driving Circuit for LED Lighting

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2014-01-01

    Full Text Available This pa\tper proposes a self-excited single-stage high power factor LED lighting driving circuit. Being featured with power factor correction capability without needing any control devices, the proposed circuit structure is with low cost and suitable for commercial production. The power factor correction function is accomplished by using inductor in combination with a half-bridge quasi resonant converter to achieve active switching and yield out voltage regulation according to load requirement. Furthermore, the zero-voltage switching in the half-bridge converter can be attained to promote the overall performance efficiency of the proposed circuit. Finally, the validity and production availability of the proposed circuit will be verified as well.

  10. Around power law for PageRank components in Buckley-Osthus model of web graph

    OpenAIRE

    Gasnikov, Alexander; Zhukovskii, Maxim; Kim, Sergey; Noskov, Fedor; Plaunov, Stepan; Smirnov, Daniil

    2017-01-01

    In the paper we investigate power law for PageRank components for the Buckley-Osthus model for web graph. We compare different numerical methods for PageRank calculation. With the best method we do a lot of numerical experiments. These experiments confirm the hypothesis about power law. At the end we discuss real model of web-ranking based on the classical PageRank approach.

  11. Dense power-law networks and simplicial complexes

    Science.gov (United States)

    Courtney, Owen T.; Bianconi, Ginestra

    2018-05-01

    There is increasing evidence that dense networks occur in on-line social networks, recommendation networks and in the brain. In addition to being dense, these networks are often also scale-free, i.e., their degree distributions follow P (k ) ∝k-γ with γ ∈(1 ,2 ] . Models of growing networks have been successfully employed to produce scale-free networks using preferential attachment, however these models can only produce sparse networks as the numbers of links and nodes being added at each time step is constant. Here we present a modeling framework which produces networks that are both dense and scale-free. The mechanism by which the networks grow in this model is based on the Pitman-Yor process. Variations on the model are able to produce undirected scale-free networks with exponent γ =2 or directed networks with power-law out-degree distribution with tunable exponent γ ∈(1 ,2 ) . We also extend the model to that of directed two-dimensional simplicial complexes. Simplicial complexes are generalization of networks that can encode the many body interactions between the parts of a complex system and as such are becoming increasingly popular to characterize different data sets ranging from social interacting systems to the brain. Our model produces dense directed simplicial complexes with power-law distribution of the generalized out-degrees of the nodes.

  12. Second-order small-disturbance solutions for hypersonic flow over power-law bodies

    Science.gov (United States)

    Townsend, J. C.

    1975-01-01

    Similarity solutions were found which give the adiabatic flow of an ideal gas about two-dimensional and axisymmetric power-law bodies at infinite Mach number to second order in the body slenderness parameter. The flow variables were expressed as a sum of zero-order and perturbation similarity functions for which the axial variations in the flow equations separated out. The resulting similarity equations were integrated numerically. The solutions, which are universal functions, are presented in graphic and tabular form. To avoid a singularity in the calculations, the results are limited to body power-law exponents greater than about 0.85 for the two-dimensional case and 0.75 for the axisymmetric case. Because of the entropy layer induced by the nose bluntness (for power-law bodies other than cones and wedges), only the pressure function is valid at the body surface. The similarity results give excellent agreement with the exact solutions for inviscid flow over wedges and cones having half-angles up to about 20 deg. They give good agreement with experimental shock-wave shapes and surface-pressure distributions for 3/4-power axisymmetric bodies, considering that Mach number and boundary-layer displacement effects are not included in the theory.

  13. Emergence of power-law in a market with mixed models

    Science.gov (United States)

    Ali Saif, M.; Gade, Prashant M.

    2007-10-01

    We investigate the problem of wealth distribution from the viewpoint of asset exchange. Robust nature of Pareto's law across economies, ideologies and nations suggests that this could be an outcome of trading strategies. However, the simple asset exchange models fail to reproduce this feature. A Yardsale (YS) model in which amount put on the bet is a fraction of minimum of the two players leads to condensation of wealth in hands of some agent while theft and fraud (TF) model in which the amount to be exchanged is a fraction of loser's wealth leads to an exponential distribution of wealth. We show that if we allow few agents to follow a different model than others, i.e., there are some agents following TF model while rest follow YS model, it leads to distribution with power-law tails. Similar effect is observed when one carries out transactions for a fraction of one's wealth using TF model and for the rest YS model is used. We also observe a power-law tail in wealth distribution if we allow the agents to follow either of the models with some probability.

  14. Learning curves in highly skilled chess players: a test of the generality of the power law of practice.

    Science.gov (United States)

    Howard, Robert W

    2014-09-01

    The power law of practice holds that a power function best interrelates skill performance and amount of practice. However, the law's validity and generality are moot. Some researchers argue that it is an artifact of averaging individual exponential curves while others question whether the law generalizes to complex skills and to performance measures other than response time. The present study tested the power law's generality to development over many years of a very complex cognitive skill, chess playing, with 387 skilled participants, most of whom were grandmasters. A power or logarithmic function best fit grouped data but individuals showed much variability. An exponential function usually was the worst fit to individual data. Groups differing in chess talent were compared and a power function best fit the group curve for the more talented players while a quadratic function best fit that for the less talented. After extreme amounts of practice, a logarithmic function best fit grouped data but a quadratic function best fit most individual curves. Individual variability is great and the power law or an exponential law are not the best descriptions of individual chess skill development. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Power-law behavior in complex organizational communication networks during crisis

    Science.gov (United States)

    Uddin, Shahadat; Murshed, Shahriar Tanvir Hasan; Hossain, Liaquat

    2011-08-01

    Communication networks can be described as patterns of contacts which are created due to the flow of messages and information shared among participating actors. Contemporary organizations are now commonly viewed as dynamic systems of adaptation and evolution containing several parts, which interact with one another both in internal and in external environment. Although there is limited consensus among researchers on the precise definition of organizational crisis, there is evidence of shared meaning: crisis produces individual crisis, crisis can be associated with positive or negative conditions, crises can be situations having been precipitated quickly or suddenly or situations that have developed over time and are predictable etc. In this research, we study the power-law behavior of an organizational email communication network during crisis from complexity perspective. Power law simply describes that, the probability that a randomly selected node has k links (i.e. degree k) follows P(k)∼k, where γ is the degree exponent. We used social network analysis tools and techniques to analyze the email communication dataset. We tested two propositions: (1) as organization goes through crisis, a few actors, who are prominent or more active, will become central, and (2) the daily communication network as well as the actors in the communication network exhibit power-law behavior. Our preliminary results support these two propositions. The outcome of this study may provide significant advancement in exploring organizational communication network behavior during crisis.

  16. Instabilities in power law gradient hardening materials

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2005-01-01

    Tension and compression instabilities are investigated for specimens with dimensions in the micron range. A finite strain generalization of a higher order strain gradient plasticity theory is implemented in a finite element scheme capable of modeling power law hardening materials. Effects...... of gradient hardening are found to delay the onset of localization under plane strain tension, and significantly reduce strain gradients in the localized zone. For plane strain compression gradient hardening is found to increase the load-carrying capacity significantly....

  17. THE FUNDAMENTAL SOLUTIONS FOR MULTI-TERM MODIFIED POWER LAW WAVE EQUATIONS IN A FINITE DOMAIN.

    Science.gov (United States)

    Jiang, H; Liu, F; Meerschaert, M M; McGough, R J

    2013-01-01

    Fractional partial differential equations with more than one fractional derivative term in time, such as the Szabo wave equation, or the power law wave equation, describe important physical phenomena. However, studies of these multi-term time-space or time fractional wave equations are still under development. In this paper, multi-term modified power law wave equations in a finite domain are considered. The multi-term time fractional derivatives are defined in the Caputo sense, whose orders belong to the intervals (1, 2], [2, 3), [2, 4) or (0, n ) ( n > 2), respectively. Analytical solutions of the multi-term modified power law wave equations are derived. These new techniques are based on Luchko's Theorem, a spectral representation of the Laplacian operator, a method of separating variables and fractional derivative techniques. Then these general methods are applied to the special cases of the Szabo wave equation and the power law wave equation. These methods and techniques can also be extended to other kinds of the multi-term time-space fractional models including fractional Laplacian.

  18. Prognostics-based qualification of high-power white LEDs using Lévy process approach

    Science.gov (United States)

    Yung, Kam-Chuen; Sun, Bo; Jiang, Xiaopeng

    2017-01-01

    Due to their versatility in a variety of applications and the growing market demand, high-power white light-emitting diodes (LEDs) have attracted considerable attention. Reliability qualification testing is an essential part of the product development process to ensure the reliability of a new LED product before its release. However, the widely used IES-TM-21 method does not provide comprehensive reliability information. For more accurate and effective qualification, this paper presents a novel method based on prognostics techniques. Prognostics is an engineering technology predicting the future reliability or determining the remaining useful lifetime (RUL) of a product by assessing the extent of deviation or degradation from its expected normal operating conditions. A Lévy subordinator of a mixed Gamma and compound Poisson process is used to describe the actual degradation process of LEDs characterized by random sporadic small jumps of degradation degree, and the reliability function is derived for qualification with different distribution forms of jump sizes. The IES LM-80 test results reported by different LED vendors are used to develop and validate the qualification methodology. This study will be helpful for LED manufacturers to reduce the total test time and cost required to qualify the reliability of an LED product.

  19. Finite sample properties of power-law cross-correlations estimators

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2015-01-01

    Roč. 419, č. 1 (2015), s. 513-525 ISSN 0378-4371 R&D Projects: GA ČR(CZ) GP14-11402P Keywords : power-law cross-correlations * long - term memory * econophysics Subject RIV: AH - Economics Impact factor: 1.785, year: 2015 http://library.utia.cas.cz/separaty/2014/E/kristoufek-0433530.pdf

  20. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    Energy Technology Data Exchange (ETDEWEB)

    Hans-Dieter Reidenbach [Cologne University of Applied Sciences Research Laboratory on Medical Technology/HLT Betzdorfer Str. 2, 50679 Koeln (Germany)

    2006-07-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  1. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    International Nuclear Information System (INIS)

    Hans-Dieter Reidenbach

    2006-01-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  2. Power laws and fragility in flow networks.

    Science.gov (United States)

    Shore, Jesse; Chu, Catherine J; Bianchi, Matt T

    2013-01-01

    What makes economic and ecological networks so unlike other highly skewed networks in their tendency toward turbulence and collapse? Here, we explore the consequences of a defining feature of these networks: their nodes are tied together by flow. We show that flow networks tend to the power law degree distribution (PLDD) due to a self-reinforcing process involving position within the global network structure, and thus present the first random graph model for PLDDs that does not depend on a rich-get-richer function of nodal degree. We also show that in contrast to non-flow networks, PLDD flow networks are dramatically more vulnerable to catastrophic failure than non-PLDD flow networks, a finding with potential explanatory power in our age of resource- and financial-interdependence and turbulence.

  3. On Origin of Power-Law Distributions in Self-Organized Criticality from Random Walk Treatment

    International Nuclear Information System (INIS)

    Cao Xiaofeng; Deng Zongwei; Yang Chunbin

    2008-01-01

    The origin of power-law distributions in self-organized criticality is investigated by treating the variation of the number of active sites in the system as a stochastic process. An avalanche is then regarded as a first-return random walk process in a one-dimensional lattice. We assume that the variation of the number of active sites has three possibilities in each update: to increase by 1 with probability f 1 , to decrease by 1 with probability f 2 , or remain unchanged with probability 1-f 1 -f 2 . This mimics the dynamics in the system. Power-law distributions of the lifetime are found when the random walk is unbiased with equal probability to move in opposite directions. This shows that power-law distributions in self-organized criticality may be caused by the balance of competitive interactions.

  4. Highly efficient and reliable high power LEDs with patterned sapphire substrate and strip-shaped distributed current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shengjun [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Yuan, Shu; Liu, Yingce [Quantum Wafer Inc., Foshan 528251 (China); Guo, L. Jay [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109 (United States); Liu, Sheng, E-mail: victor_liu63@126.com [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Ding, Han [State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-11-15

    Graphical abstract: - Highlights: • TEM is used to characterize threading dislocation existing in GaN epitaxial layer. • Effect of threading dislocation on optical and electrical of LEDs is discussed. • Strip-shaped SiO{sub 2} DCBL is designed to improve current spreading performance of LEDs. - Abstract: We demonstrated that the improvement in optical and electrical performance of high power LEDs was achieved using cone-shaped patterned sapphire substrate (PSS) and strip-shaped SiO{sub 2} distributed current blocking layer (DCBL). We found through transmission electron microscopy (TEM) observation that densities of both the screw dislocation and edge dislocation existing in GaN epitaxial layer grown on PSS were much less than that of GaN epitaxial layer grown on flat sapphire substrate (FSS). Compared to LED grown on FSS, LED grown on PSS showed higher sub-threshold forward-bias voltage and lower reverse leakage current, resulting in an enhancement in device reliability. We also designed a strip-shaped SiO{sub 2} DCBL beneath a strip-shaped p-electrode, which prevents the current from being concentrated on regions immediately adjacent the strip-shaped p-electrode, thereby facilitating uniform current spreading into the active region. By implementing strip-shaped SiO{sub 2} DCBL, light output power of high power PSS-LED chip could be further increased by 13%.

  5. Power law load dependence of atomic friction

    OpenAIRE

    Fusco, C.; Fasolino, A.

    2004-01-01

    We present a theoretical study of the dynamics of a tip scanning a graphite surface as a function of the applied load. From the analysis of the lateral forces, we extract the friction force and the corrugation of the effective tip-surface interaction potential. We find both the friction force and potential amplitude to have a power-law dependence on applied load with exponent similar to1.6. We interpret these results as characteristic of sharp undeformable tips in contrast to the case of macr...

  6. Power Politics and the Rule of Law in Post-Dayton Bosnia

    Directory of Open Access Journals (Sweden)

    Timothy Donais

    2013-06-01

    Full Text Available Over the past two decades, therule of law has emerged as a key priority within contemporary peacebuildingefforts. Drawing on examples from post-Dayton Bosnia, this article examines theimpact of rule of law reform efforts on broader patterns of power and politicalauthority in peacebuilding contexts. It suggests that in the case of Bosnia,the use of rule of law strategies to restructure political life has largelyfailed. Thus, despite some notable achievements on the rule of law front, thecore dynamics of Bosnia’s political conflict remain intact, and country’s peaceprocess is as fragile as ever. The article concludes by noting that charting acourse between accepting the political status quo and fundamentallytransforming it requires more nuanced approaches that advance the rule of laweven while accepting its limits as an instrument of deep politicaltransformation.

  7. Regularized lattice Boltzmann model for immiscible two-phase flows with power-law rheology

    Science.gov (United States)

    Ba, Yan; Wang, Ningning; Liu, Haihu; Li, Qiang; He, Guoqiang

    2018-03-01

    In this work, a regularized lattice Boltzmann color-gradient model is developed for the simulation of immiscible two-phase flows with power-law rheology. This model is as simple as the Bhatnagar-Gross-Krook (BGK) color-gradient model except that an additional regularization step is introduced prior to the collision step. In the regularization step, the pseudo-inverse method is adopted as an alternative solution for the nonequilibrium part of the total distribution function, and it can be easily extended to other discrete velocity models no matter whether a forcing term is considered or not. The obtained expressions for the nonequilibrium part are merely related to macroscopic variables and velocity gradients that can be evaluated locally. Several numerical examples, including the single-phase and two-phase layered power-law fluid flows between two parallel plates, and the droplet deformation and breakup in a simple shear flow, are conducted to test the capability and accuracy of the proposed color-gradient model. Results show that the present model is more stable and accurate than the BGK color-gradient model for power-law fluids with a wide range of power-law indices. Compared to its multiple-relaxation-time counterpart, the present model can increase the computing efficiency by around 15%, while keeping the same accuracy and stability. Also, the present model is found to be capable of reasonably predicting the critical capillary number of droplet breakup.

  8. New power economy law for electricity and gas

    International Nuclear Information System (INIS)

    Heller, W.

    2004-01-01

    Since August 4, 2003, the so-called Directives on Speeding up Common Regulations for the Single Market for Electricity and Common Regulations for the Single Market for Gas have been in force (Official Journal of the European Communities L 176/37). These Directives must be translated into national law by July 1, 2004. The national legislative process in Germany for a Power Economy Act adapted accordingly is presented and evaluated. (orig.)

  9. Power-law behaviour evaluation from foreign exchange market data using a wavelet transform method

    Science.gov (United States)

    Wei, H. L.; Billings, S. A.

    2009-09-01

    Numerous studies in the literature have shown that the dynamics of many time series including observations in foreign exchange markets exhibit scaling behaviours. A simple new statistical approach, derived from the concept of the continuous wavelet transform correlation function (WTCF), is proposed for the evaluation of power-law properties from observed data. The new method reveals that foreign exchange rates obey power-laws and thus belong to the class of self-similarity processes.

  10. Power-law behaviour evaluation from foreign exchange market data using a wavelet transform method

    Energy Technology Data Exchange (ETDEWEB)

    Wei, H.L., E-mail: w.hualiang@sheffield.ac.u [Department of Automatic Control and Systems Engineering, the University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Billings, S.A., E-mail: s.billings@sheffield.ac.u [Department of Automatic Control and Systems Engineering, the University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom)

    2009-09-07

    Numerous studies in the literature have shown that the dynamics of many time series including observations in foreign exchange markets exhibit scaling behaviours. A simple new statistical approach, derived from the concept of the continuous wavelet transform correlation function (WTCF), is proposed for the evaluation of power-law properties from observed data. The new method reveals that foreign exchange rates obey power-laws and thus belong to the class of self-similarity processes.

  11. Power-law behaviour evaluation from foreign exchange market data using a wavelet transform method

    International Nuclear Information System (INIS)

    Wei, H.L.; Billings, S.A.

    2009-01-01

    Numerous studies in the literature have shown that the dynamics of many time series including observations in foreign exchange markets exhibit scaling behaviours. A simple new statistical approach, derived from the concept of the continuous wavelet transform correlation function (WTCF), is proposed for the evaluation of power-law properties from observed data. The new method reveals that foreign exchange rates obey power-laws and thus belong to the class of self-similarity processes.

  12. The Dynamics of Power laws: Fitness and Aging in Preferential Attachment Trees

    Science.gov (United States)

    Garavaglia, Alessandro; van der Hofstad, Remco; Woeginger, Gerhard

    2017-09-01

    Continuous-time branching processes describe the evolution of a population whose individuals generate a random number of children according to a birth process. Such branching processes can be used to understand preferential attachment models in which the birth rates are linear functions. We are motivated by citation networks, where power-law citation counts are observed as well as aging in the citation patterns. To model this, we introduce fitness and age-dependence in these birth processes. The multiplicative fitness moderates the rate at which children are born, while the aging is integrable, so that individuals receives a finite number of children in their lifetime. We show the existence of a limiting degree distribution for such processes. In the preferential attachment case, where fitness and aging are absent, this limiting degree distribution is known to have power-law tails. We show that the limiting degree distribution has exponential tails for bounded fitnesses in the presence of integrable aging, while the power-law tail is restored when integrable aging is combined with fitness with unbounded support with at most exponential tails. In the absence of integrable aging, such processes are explosive.

  13. Air-chemistry "turbulence": power-law scaling and statistical regularity

    Directory of Open Access Journals (Sweden)

    H.-m. Hsu

    2011-08-01

    Full Text Available With the intent to gain further knowledge on the spectral structures and statistical regularities of surface atmospheric chemistry, the chemical gases (NO, NO2, NOx, CO, SO2, and O3 and aerosol (PM10 measured at 74 air quality monitoring stations over the island of Taiwan are analyzed for the year of 2004 at hourly resolution. They represent a range of surface air quality with a mixed combination of geographic settings, and include urban/rural, coastal/inland, plain/hill, and industrial/agricultural locations. In addition to the well-known semi-diurnal and diurnal oscillations, weekly, and intermediate (20 ~ 30 days peaks are also identified with the continuous wavelet transform (CWT. The spectra indicate power-law scaling regions for the frequencies higher than the diurnal and those lower than the diurnal with the average exponents of −5/3 and −1, respectively. These dual-exponents are corroborated with those with the detrended fluctuation analysis in the corresponding time-lag regions. These exponents are mostly independent of the averages and standard deviations of time series measured at various geographic settings, i.e., the spatial inhomogeneities. In other words, they possess dominant universal structures. After spectral coefficients from the CWT decomposition are grouped according to the spectral bands, and inverted separately, the PDFs of the reconstructed time series for the high-frequency band demonstrate the interesting statistical regularity, −3 power-law scaling for the heavy tails, consistently. Such spectral peaks, dual-exponent structures, and power-law scaling in heavy tails are important structural information, but their relations to turbulence and mesoscale variability require further investigations. This could lead to a better understanding of the processes controlling air quality.

  14. Knoop hardness of ten resin composites irradiated with high-power LED and quartz-tungsten-halogen lights.

    Science.gov (United States)

    Price, Richard B T; Felix, Corey A; Andreou, Pantelis

    2005-05-01

    This study compared a high-power light-emitting-diode (LED) curing light (FreeLight 2, 3M ESPE) with a quartz-tungsten-halogen (QTH) light (TriLight, 3M ESPE) to determine which was the better at photo-polymerising 10 resin composites. Class I preparations were prepared 4-mm deep into human teeth and filled with 10 different composites. The composites were irradiated for 50% or 100% of their recommended times using the LED light, and for 100% of their recommended times with the QTH light on either the high or medium power setting. Fifteen minutes later, the Knoop hardness of the composites was measured to a depth of 3.5 mm from the surface. When irradiated by the LED light for their recommended curing times, the Knoop hardness of all 10 composites stayed above 80% of the maximum hardness of the composite to a depth of at least 1.5 mm; three composites maintained a Knoop hardness that was more than 80% of their maximum hardness to a depth of 3.5 mm. Repeated measurements analysis of variance indicated that all the two-way and three-way interactions between the curing light, depth, and composite were significant (p hardness values. The LED light, used for the composite manufacturer's recommended time, was ranked the best at curing the composites to a depth of 3mm (p power setting.

  15. Cluster tails for critical power-law inhomogeneous random graphs

    NARCIS (Netherlands)

    van der Hofstad, R.; Kliem, S.; van Leeuwaarden, J.S.H.

    2018-01-01

    Recently, the scaling limit of cluster sizes for critical inhomogeneous random graphs of rank-1 type having finite variance but infinite third moment degrees was obtained in Bhamidi et al. (Ann Probab 40:2299–2361, 2012). It was proved that when the degrees obey a power law with exponent τ∈ (3 , 4)

  16. Hypersonic aerodynamic characteristics of a family of power-law, wing body configurations

    Science.gov (United States)

    Townsend, J. C.

    1973-01-01

    The configurations analyzed are half-axisymmetric, power-law bodies surmounted by thin, flat wings. The wing planform matches the body shock-wave shape. Analytic solutions of the hypersonic small disturbance equations form a basis for calculating the longitudinal aerodynamic characteristics. Boundary-layer displacement effects on the body and the wing upper surface are approximated. Skin friction is estimated by using compressible, laminar boundary-layer solutions. Good agreement was obtained with available experimental data for which the basic theoretical assumptions were satisfied. The method is used to estimate the effects of power-law, fineness ratio, and Mach number variations at full-scale conditions. The computer program is included.

  17. “Slimming” of power-law tails by increasing market returns

    Science.gov (United States)

    Sornette, D.

    2002-06-01

    We introduce a simple generalization of rational bubble models which removes the fundamental problem discovered by Lux and Sornette (J. Money, Credit and Banking, preprint at http://xxx.lanl.gov/abs/cond-mat/9910141) that the distribution of returns is a power law with exponent discount rate rδ, the distribution of returns of the observable price, sum of the bubble component and of the fundamental price, exhibits an intermediate tail with an exponent which can be larger than 1. This regime r> rδ corresponds to a generalization of the rational bubble model in which the fundamental price is no more given by the discounted value of future dividends. We explain how this is possible. Our model predicts that, the higher is the market remuneration r above the discount rate, the larger is the power-law exponent and thus the thinner is the tail of the distribution of price returns.

  18. Mapping the Power of Law Professors: The Role of Scientific and Social Capital

    Science.gov (United States)

    Bühlmann, Felix; Benz, Pierre; Mach, André; Rossier, Thierry

    2017-01-01

    As a scientific discipline and profession, law has been for centuries at the heart of social and political power of many Western societies. Professors of law, as influential representatives of the profession, are important powerbrokers between academia, politics and the corporate world. Their influence is based on scientific reputation,…

  19. IMPLEMENTATION OF ENERGY LAW OF HYBRID POWER STATION FOR SOCIAL WELFARE

    Directory of Open Access Journals (Sweden)

    Dyah Ayu Widowati

    2014-11-01

    Full Text Available This study was aimed to investigate the Implementation of Energy Law of Hybrid Power Station for Social Welfare in Pantai Baru. The problem formulations are the management and utilization of hybrid power station in Pantai Baru and implementation of energy law of hybrid power station for social welfare in the fields of economy and information in Pantai Baru. Based on data analysis it is concluded that the management of hybrid power station in Pantai Baru is performed collaboratively between government and the society. The existence of hybrid power station in pantai baru has positive impacts in economy and information. Penelitian ini meneliti Pelaksanaan Hukum Energi Pembangkit Listrik Tenaga Hibrid untuk Kesejahteraan Rakyat di Bidang Ekonomi dan Informasi di Pantai Baru. Masalah yang diteliti adalah bentuk pengelolaan dan pemanfaatan pembangkit listrik tenaga hibrid di Pantai Baru dan pelaksanaan hukum energi pembangkit listrik tenaga hibrid untuk kesejahteraan rakyat di bidang ekonomi dan informasi di Pantai Baru. Berdasarkan analisis data dapat disimpulkan bahwa pengelolaan pembangkit listrik tenaga hibrid yang ada di pantai baru dilakukan secara kolaboratif, antara pemerintah dengan masyarakat. Kehadiran pembangkit listrik tenaga hibrid yang ada di pantai baru telah memberikan dampak positif di bidang ekonomi dan informasi.

  20. ANALYSIS OF MARANGONI CONVECTION OF NON-NEWTONIAN POWER LAW FLUIDS WITH LINEAR TEMPERATURE DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2011-01-01

    Full Text Available The problem of steady, laminar, thermal Marangoni convection flow of non-Newtonian power law fluid along a horizontal surface with variable surface temperature is studied. The partial differential equations are transformed into ordinary differential equations by using a suitable similarity transformation and analytical approximate solutions are obtained by an efficient transformation, asymptotic expansion and Padé approximants technique. The effects of power law index and Marangoni number on velocity and temperature profiles are examined and discussed.

  1. Law concerning water and nuclear power station licensing

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The competent water authority, within the purview of the legal provisions concerning water is entitled to define a maximum of radioactive contamination of cooling water taken from and re-fed into the Rhine river, and is entitled to make such limit form part of the permit granted to a nuclear power station (here: Biblis B reactor). This right is not overruled by sections 45, 46 of the Rad. Protection Ordinance which determine dose limits (among others also for radioactivity released through waste water), and which state the competent licensing authority under atomic energy law to be entitled to set higher or lower limits by discretion. The provisions of sections 45 ff Rad. Prot. Ordinance are to be interpreted to mean that since the competent authority in accordance with section 46, sub-sections (2) and (5) Rad. Prot. Ordinance is given the right to define maximum acceptable radioactivity release through water discharge, it many also define the lowest limit of contamination and is hence entitled to declare discharged cooling water not to fall under atomic energy law, but rather under the law relating to water management. (orig.) [de

  2. Mapping Power Law Distributions in Digital Health Social Networks: Methods, Interpretations, and Practical Implications.

    Science.gov (United States)

    van Mierlo, Trevor; Hyatt, Douglas; Ching, Andrew T

    2015-06-25

    Social networks are common in digital health. A new stream of research is beginning to investigate the mechanisms of digital health social networks (DHSNs), how they are structured, how they function, and how their growth can be nurtured and managed. DHSNs increase in value when additional content is added, and the structure of networks may resemble the characteristics of power laws. Power laws are contrary to traditional Gaussian averages in that they demonstrate correlated phenomena. The objective of this study is to investigate whether the distribution frequency in four DHSNs can be characterized as following a power law. A second objective is to describe the method used to determine the comparison. Data from four DHSNs—Alcohol Help Center (AHC), Depression Center (DC), Panic Center (PC), and Stop Smoking Center (SSC)—were compared to power law distributions. To assist future researchers and managers, the 5-step methodology used to analyze and compare datasets is described. All four DHSNs were found to have right-skewed distributions, indicating the data were not normally distributed. When power trend lines were added to each frequency distribution, R(2) values indicated that, to a very high degree, the variance in post frequencies can be explained by actor rank (AHC .962, DC .975, PC .969, SSC .95). Spearman correlations provided further indication of the strength and statistical significance of the relationship (AHC .987. DC .967, PC .983, SSC .993, Ppower distributions across multiple DHSNs, each addressing a unique condition. Results indicate that despite vast differences in theme, content, and length of existence, DHSNs follow properties of power laws. The structure of DHSNs is important as it gives insight to researchers and managers into the nature and mechanisms of network functionality. The 5-step process undertaken to compare actor contribution patterns can be replicated in networks that are managed by other organizations, and we conjecture that

  3. Experimental investigation of a PCM-HP heat sink on its thermal performance and anti-thermal-shock capacity for high-power LEDs

    International Nuclear Information System (INIS)

    Wu, Yuxuan; Tang, Yong; Li, Zongtao; Ding, Xinrui; Yuan, Wei; Zhao, Xuezhi; Yu, Binhai

    2016-01-01

    Highlights: • A phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) is designed. • The PCM-HP heat sink can significantly lower the LED heating rate and temperature. • The PCM-HP heat sink achieves a best anti-thermal-shock capacity in LED cyclic working modes. - Abstract: High-power LEDs demonstrate a number of benefits compared with conventional incandescent lamps and fluorescent lamps, including a longer lifetime, higher brightness and lower power consumption. However, owing to their severe high heat flux, it is difficult to develop effective thermal management of high-power LEDs, especially under cyclic working modes, which cause serious periodic thermal stress and limit further development. Focusing on the above problem, this paper designed a phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) that consists of a PCM base, adapter plate, heat pipe and finned radiator. Different parameters, such as three types of interior materials to fill the heat sink, three LED power inputs and eight LED cyclic working modes, were separately studied to investigate the thermal performance and anti-thermal-shock capacity of the PCM-HP heat sink. The results show that the PCM-HP heat sink possesses remarkable thermal performance owing to the reduction of the LED heating rate and peak temperature. More importantly, an excellent anti-thermal-shock capacity of the PCM-HP heat sink is also demonstrated when applied in LED cyclic working modes, and this capacity demonstrates the best range.

  4. Power Law Distributions in the Experiment for Adjustment of the Ion Source of the NBI System

    International Nuclear Information System (INIS)

    Han Xiaopu; Hu Chundong

    2005-01-01

    The experiential adjustment process in an experiment on the ion source of the neutral beam injector system for the HT-7 Tokamak is reported in this paper. With regard to the data obtained in the same condition, in arranging the arc current intensities of every shot with a decay rank, the distributions of the arc current intensity correspond to the power laws, and the distribution obtained in the condition with the cryo-pump corresponds to the double Pareto distribution. Using the similar study method, the distributions of the arc duration are close to the power laws too. These power law distributions are formed rather naturally instead of being the results of purposeful seeking

  5. Low power wide spectrum optical transmitter using avalanche mode LEDs in SOI CMOS technology

    NARCIS (Netherlands)

    Agarwal, V.; Dutta, S; Annema, AJ; Hueting, RJE; Steeneken, P.G.; Nauta, B

    2017-01-01

    This paper presents a low power monolithically integrated optical transmitter with avalanche mode light emitting diodes in a 140 nm silicon-on-insulator CMOS technology. Avalanche mode LEDs in silicon exhibit wide-spectrum electroluminescence (400 nm < λ < 850 nm), which has a significant

  6. Prevention of damage and 'residual risk' in nuclear power laws

    International Nuclear Information System (INIS)

    Greipl, C.

    1992-01-01

    The concept of prevention of damage within the framework of nuclear power laws includes averting danger for the protection of third parties and preventing risks for the partial protection of third parties with the proviso that still a desire to use the concept 'residual risk' in addition, it should be limited, on the grounds of what can be reasonably expected, to those risks which cannot be reduced any further by the government, i.e. to risks which the public in general and third parties ('actually') must accept. In the future, questions regarding safety systems should be taken into account exclusively withing the context of 'what is necessary for protection against damage in keeping with the latest developments in science and technology' and not at the discretion of the law in denying permission according to Article 7 Paragraph 2 Atomic Energy Law. (orig.) [de

  7. Orbits in elementary, power-law galaxy bars - 1. Occurrence and role of single loops

    Science.gov (United States)

    Struck, Curtis

    2018-05-01

    Orbits in galaxy bars are generally complex, but simple closed loop orbits play an important role in our conceptual understanding of bars. Such orbits are found in some well-studied potentials, provide a simple model of the bar in themselves, and may generate complex orbit families. The precessing, power ellipse (p-ellipse) orbit approximation provides accurate analytic orbit fits in symmetric galaxy potentials. It remains useful for finding and fitting simple loop orbits in the frame of a rotating bar with bar-like and symmetric power-law potentials. Second-order perturbation theory yields two or fewer simple loop solutions in these potentials. Numerical integrations in the parameter space neighbourhood of perturbation solutions reveal zero or one actual loops in a range of such potentials with rising rotation curves. These loops are embedded in a small parameter region of similar, but librating orbits, which have a subharmonic frequency superimposed on the basic loop. These loops and their librating companions support annular bars. Solid bars can be produced in more complex potentials, as shown by an example with power-law indices varying with radius. The power-law potentials can be viewed as the elementary constituents of more complex potentials. Numerical integrations also reveal interesting classes of orbits with multiple loops. In two-dimensional, self-gravitating bars, with power-law potentials, single-loop orbits are very rare. This result suggests that gas bars or oval distortions are unlikely to be long-lived, and that complex orbits or three-dimensional structure must support self-gravitating stellar bars.

  8. Non-coulombic effective power-law potential for the heavy quarkoniums

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N; Jena, S N [Utkal Univ., Bhubaneswar (India). Dept. of Physics

    1980-12-01

    An effective power-law potential of the form V(r) = 6.08 r/sup 0/sup(.)/sup 106/ - 6.41 is found to describe satisfactorily the gross features of the mass spectra and the leptonic width ratios of the cc and bb systems in a flavour-independent manner.

  9. Networks of power in digital copyright law and policy political salience, expertise and the legislative process

    CERN Document Server

    Farrand, Benjamin

    2014-01-01

    In this book, Benjamin Farrand employs an interdisciplinary approach that combines legal analysis with political theory to explore the development of copyright law in the EU. Farrand utilises Foucault's concept of Networks of Power and Culpepper's Quiet Politics to assess the adoption and enforcement of copyright law in the EU, including the role of industry representative, cross-border licensing, and judicial approaches to territorial restrictions. Focusing in particular on legislative initiatives concerning copyright, digital music and the internet, Networks of Power in Digital Copyright Law and Policy: Political Salience, Expertise and the Legislative Process demonstrates the connection between copyright law and complex network relationships. This book presents an original socio-political theoretical framework for assessing developments in copyright law that will interest researchers and post-graduate students of law and politics, as well as those more particularly concerned with political theory, EU and c...

  10. Finite-size effects in transcript sequencing count distribution: its power-law correction necessarily precedes downstream normalization and comparative analysis.

    Science.gov (United States)

    Wong, Wing-Cheong; Ng, Hong-Kiat; Tantoso, Erwin; Soong, Richie; Eisenhaber, Frank

    2018-02-12

    Though earlier works on modelling transcript abundance from vertebrates to lower eukaroytes have specifically singled out the Zip's law, the observed distributions often deviate from a single power-law slope. In hindsight, while power-laws of critical phenomena are derived asymptotically under the conditions of infinite observations, real world observations are finite where the finite-size effects will set in to force a power-law distribution into an exponential decay and consequently, manifests as a curvature (i.e., varying exponent values) in a log-log plot. If transcript abundance is truly power-law distributed, the varying exponent signifies changing mathematical moments (e.g., mean, variance) and creates heteroskedasticity which compromises statistical rigor in analysis. The impact of this deviation from the asymptotic power-law on sequencing count data has never truly been examined and quantified. The anecdotal description of transcript abundance being almost Zipf's law-like distributed can be conceptualized as the imperfect mathematical rendition of the Pareto power-law distribution when subjected to the finite-size effects in the real world; This is regardless of the advancement in sequencing technology since sampling is finite in practice. Our conceptualization agrees well with our empirical analysis of two modern day NGS (Next-generation sequencing) datasets: an in-house generated dilution miRNA study of two gastric cancer cell lines (NUGC3 and AGS) and a publicly available spike-in miRNA data; Firstly, the finite-size effects causes the deviations of sequencing count data from Zipf's law and issues of reproducibility in sequencing experiments. Secondly, it manifests as heteroskedasticity among experimental replicates to bring about statistical woes. Surprisingly, a straightforward power-law correction that restores the distribution distortion to a single exponent value can dramatically reduce data heteroskedasticity to invoke an instant increase in

  11. The United Kingdom Law on the authorisation of nuclear power stations

    International Nuclear Information System (INIS)

    Savinson, R.

    1977-01-01

    This paper explains the requirements of the law of the United Kingdom as to the authorisations needed to construct and operate nuclear power plants in Great Britain. For simplicity, the texts referred to apply to England and Wales, Scottish law differing in detail but not in principle. Implementation of this legal system is studied in particular from the viewpoint of the Central Electricity Generating Board (CEGB) which is at present the body exclusively responsible for generating and supplying electricity in England and Wales. (NEA) [fr

  12. Power law distributions of patents as indicators of innovation.

    Directory of Open Access Journals (Sweden)

    Dion R J O'Neale

    Full Text Available The total number of patents produced by a country (or the number of patents produced per capita is often used as an indicator for innovation. Here we present evidence that the distribution of patents amongst applicants within many countries is well-described by power laws with exponents that vary between 1.66 (Japan and 2.37 (Poland. We suggest that this exponent is a useful new metric for studying innovation. Using simulations based on simple preferential attachment-type rules that generate power laws, we find we can explain some of the variation in exponents between countries, with countries that have larger numbers of patents per applicant generally exhibiting smaller exponents in both the simulated and actual data. Similarly we find that the exponents for most countries are inversely correlated with other indicators of innovation, such as research and development intensity or the ubiquity of export baskets. This suggests that in more advanced economies, which tend to have smaller values of the exponent, a greater proportion of the total number of patents are filed by large companies than in less advanced countries.

  13. Influence of power-law index on an unsteady exothermic reaction ...

    African Journals Online (AJOL)

    This study presents the solution of an unsteady Arrhenius exothermic reaction where we reduced the exponential term to a power-law approximation. A numerical solution of the problem is obtained using shooting technique with second order Runge-Kuta scheme. It is shown that the temperature of the reactant depends on ...

  14. Nonlinear quenches of power-law confining traps in quantum critical systems

    International Nuclear Information System (INIS)

    Collura, Mario; Karevski, Dragi

    2011-01-01

    We describe the coherent quantum evolution of a quantum many-body system with a time-dependent power-law confining potential. The amplitude of the inhomogeneous potential is driven in time along a nonlinear ramp which crosses a critical point. Using Kibble-Zurek-like scaling arguments we derive general scaling laws for the density of excitations and energy excess generated during the nonlinear sweep of the confining potential. It is shown that, with respect to the sweeping rate, the densities follow algebraic laws with exponents that depend on the space-time properties of the potential and on the scaling dimensions of the densities. We support our scaling predictions with both analytical and numerical results on the Ising quantum chain with an inhomogeneous transverse field varying in time.

  15. Black swans, power laws, and dragon-kings: Earthquakes, volcanic eruptions, landslides, wildfires, floods, and SOC models

    Science.gov (United States)

    Sachs, M. K.; Yoder, M. R.; Turcotte, D. L.; Rundle, J. B.; Malamud, B. D.

    2012-05-01

    Extreme events that change global society have been characterized as black swans. The frequency-size distributions of many natural phenomena are often well approximated by power-law (fractal) distributions. An important question is whether the probability of extreme events can be estimated by extrapolating the power-law distributions. Events that exceed these extrapolations have been characterized as dragon-kings. In this paper we consider extreme events for earthquakes, volcanic eruptions, wildfires, landslides and floods. We also consider the extreme event behavior of three models that exhibit self-organized criticality (SOC): the slider-block, forest-fire, and sand-pile models. Since extrapolations using power-laws are widely used in probabilistic hazard assessment, the occurrence of dragon-king events have important practical implications.

  16. Power laws and self-organized criticality in theory and nature

    International Nuclear Information System (INIS)

    Marković, Dimitrije; Gros, Claudius

    2014-01-01

    Power laws and distributions with heavy tails are common features of many complex systems. Examples are the distribution of earthquake magnitudes, solar flare intensities and the sizes of neuronal avalanches. Previously, researchers surmised that a single general concept may act as an underlying generative mechanism, with the theory of self organized criticality being a weighty contender. The power-law scaling observed in the primary statistical analysis is an important, but by far not the only feature characterizing experimental data. The scaling function, the distribution of energy fluctuations, the distribution of inter-event waiting times, and other higher order spatial and temporal correlations, have seen increased consideration over the last years. Leading to realization that basic models, like the original sandpile model, are often insufficient to adequately describe the complexity of real-world systems with power-law distribution. Consequently, a substantial amount of effort has gone into developing new and extended models and, hitherto, three classes of models have emerged. The first line of models is based on a separation between the time scales of an external drive and an internal dissipation, and includes the original sandpile model and its extensions, like the dissipative earthquake model. Within this approach the steady state is close to criticality in terms of an absorbing phase transition. The second line of models is based on external drives and internal dynamics competing on similar time scales and includes the coherent noise model, which has a non-critical steady state characterized by heavy-tailed distributions. The third line of models proposes a non-critical self-organizing state, being guided by an optimization principle, such as the concept of highly optimized tolerance. We present a comparative overview regarding distinct modeling approaches together with a discussion of their potential relevance as underlying generative models for real

  17. Power laws and self-organized criticality in theory and nature

    Energy Technology Data Exchange (ETDEWEB)

    Marković, Dimitrije, E-mail: markovic@cbs.mpg.de [Institute for Theoretical Physics, Goethe University Frankfurt (Germany); Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig (Germany); Biomagnetic Center, Hans Berger Clinic for Neurology, University Hospital Jena, Jena (Germany); Gros, Claudius, E-mail: gros@itp.uni-frankfurt.de [Institute for Theoretical Physics, Goethe University Frankfurt (Germany)

    2014-03-01

    Power laws and distributions with heavy tails are common features of many complex systems. Examples are the distribution of earthquake magnitudes, solar flare intensities and the sizes of neuronal avalanches. Previously, researchers surmised that a single general concept may act as an underlying generative mechanism, with the theory of self organized criticality being a weighty contender. The power-law scaling observed in the primary statistical analysis is an important, but by far not the only feature characterizing experimental data. The scaling function, the distribution of energy fluctuations, the distribution of inter-event waiting times, and other higher order spatial and temporal correlations, have seen increased consideration over the last years. Leading to realization that basic models, like the original sandpile model, are often insufficient to adequately describe the complexity of real-world systems with power-law distribution. Consequently, a substantial amount of effort has gone into developing new and extended models and, hitherto, three classes of models have emerged. The first line of models is based on a separation between the time scales of an external drive and an internal dissipation, and includes the original sandpile model and its extensions, like the dissipative earthquake model. Within this approach the steady state is close to criticality in terms of an absorbing phase transition. The second line of models is based on external drives and internal dynamics competing on similar time scales and includes the coherent noise model, which has a non-critical steady state characterized by heavy-tailed distributions. The third line of models proposes a non-critical self-organizing state, being guided by an optimization principle, such as the concept of highly optimized tolerance. We present a comparative overview regarding distinct modeling approaches together with a discussion of their potential relevance as underlying generative models for real

  18. Quantum dots with indirect band gap: power-law photoluminescence decay

    Czech Academy of Sciences Publication Activity Database

    Král, Karel; Menšík, Miroslav

    2014-01-01

    Roč. 11, č. 5 (2014), s. 507-512 ISSN 1708-5284 R&D Projects: GA MŠk LH12236; GA MŠk LH12186 Institutional support: RVO:68378271 ; RVO:61389013 Keywords : photoluminescence * quantum dots * electron-phonon interaction * inter-valley deformation potential interaction * power-law decay Subject RIV: BM - Solid Matter Physics ; Magnetism

  19. An explanation for the universal 3.5 power-law observed in currency markets

    Directory of Open Access Journals (Sweden)

    Nicholas A. Johnson

    Full Text Available We present a mathematical theory to explain a recent empirical finding in the Physics literature (Zhao et al., 2013 in which the distributions of waiting-times between discrete events were found to exhibit power-law tails with an apparent universal exponent: α∼3.5. This new theory provides the first ever qualitative and quantitative explanation of Zhao et al.’s surprising finding. It also provides a mechanistic description of the origin of the observed universality, assigning its cause to the emergence of dynamical feedback processes between evolving clusters of like-minded agents. Keywords: Complex systems, Econophysics, Collective, Power law

  20. The end of nuclear power? The conflict of politics, ecology and law

    International Nuclear Information System (INIS)

    Strassburg, W.

    1999-01-01

    The German federal government's demand to opt out of the peaceful use of nuclear power is examined under aspects of constitutional law. Constitutional barriers allow the peaceful use of nuclear power to be discontinued without any compensation only in the distant future. A general restriction of the useful life of plants does not constitute a modification of ownership rights but deprivation, i.e., expropriation. In this politically desired opt-out, the government also must bear in mind that the constitution protects not only the property but also the freedom to exercise their profession (Article 12, para. 1, German Basic Law) of all those who have been committed to this industry for decades. Also a national ban on reprocessing with transborder effects violates existing law, counteracting the requirement of a free exchange of goods and services within the single European market. Moreover, the existing reprocessing contracts with foreign companies may be terminated unilaterally only subject to indemnification, as they constitute obligations under international law, unless German customers were to exercise their contractual right to cancel. In addition, it is to be feared that discontinuation of the peaceful uses of nuclear power manifests itself in the absence of provisions for the back end of the fuel cycle. Prolonging the exploration of repositories and, consequently, relying more and more heavily on interim stores, is bound to raise the question of the evidence of spent fuel and waste management in these latter facilities. In the absence of sufficient proof of waste management provisions in interim stores, the accusation could be leveled that it was not certain whether these interim stores were not turning into final stores. (orig.) [de

  1. Study of system dynamics model and control of a high-power LED lighting luminaire

    International Nuclear Information System (INIS)

    Huang, B.-J.; Hsu, P.-C.; Wu, M.-S.; Tang, C.-W.

    2007-01-01

    The purpose of the present study is to design a current control system which is robust to the system dynamics uncertainty and the disturbance of ambient temperature to assure a stable optical output property of LED. The system dynamics model of the LED lighting system was first derived. A 96 W high-power LED luminaire was designed and built in the present study. The linearly perturbed system dynamics model for the LED luminaire is derived experimentally. The dynamics model of LED lighting system is of a multiple-input-multiple-output (MIMO) system with two inputs (applied voltage and ambient temperature) and two outputs (forward current and heat conducting body temperature). A step response test method was employed to the 96 W LED luminaire to identify the system dynamics model. It is found that the current model is just a constant gain (resistance) and the disturbance model is of first order, both changing with operating conditions (voltage and ambient temperature). A feedback control system using PI algorithm was designed using the results of the system dynamics model. The control system was implemented on a PIC microprocessor. Experimental results show that the control system can stably and accurately control the LED current to a constant value at the variation of ambient temperature up to 40 o C. The control system is shown to have a robust property with respect to the plant uncertainty and the ambient temperature disturbance

  2. Are there laws of genome evolution?

    Directory of Open Access Journals (Sweden)

    Eugene V Koonin

    2011-08-01

    Full Text Available Research in quantitative evolutionary genomics and systems biology led to the discovery of several universal regularities connecting genomic and molecular phenomic variables. These universals include the log-normal distribution of the evolutionary rates of orthologous genes; the power law-like distributions of paralogous family size and node degree in various biological networks; the negative correlation between a gene's sequence evolution rate and expression level; and differential scaling of functional classes of genes with genome size. The universals of genome evolution can be accounted for by simple mathematical models similar to those used in statistical physics, such as the birth-death-innovation model. These models do not explicitly incorporate selection; therefore, the observed universal regularities do not appear to be shaped by selection but rather are emergent properties of gene ensembles. Although a complete physical theory of evolutionary biology is inconceivable, the universals of genome evolution might qualify as "laws of evolutionary genomics" in the same sense "law" is understood in modern physics.

  3. Universal correlations and power-law tails in financial covariance matrices

    Science.gov (United States)

    Akemann, G.; Fischmann, J.; Vivo, P.

    2010-07-01

    We investigate whether quantities such as the global spectral density or individual eigenvalues of financial covariance matrices can be best modelled by standard random matrix theory or rather by its generalisations displaying power-law tails. In order to generate individual eigenvalue distributions a chopping procedure is devised, which produces a statistical ensemble of asset-price covariances from a single instance of financial data sets. Local results for the smallest eigenvalue and individual spacings are very stable upon reshuffling the time windows and assets. They are in good agreement with the universal Tracy-Widom distribution and Wigner surmise, respectively. This suggests a strong degree of robustness especially in the low-lying sector of the spectra, most relevant for portfolio selections. Conversely, the global spectral density of a single covariance matrix as well as the average over all unfolded nearest-neighbour spacing distributions deviate from standard Gaussian random matrix predictions. The data are in fair agreement with a recently introduced generalised random matrix model, with correlations showing a power-law decay.

  4. Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions

    International Nuclear Information System (INIS)

    Gong Jingyu; Du Jiulin; Liu Zhipeng

    2012-01-01

    The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution of each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.

  5. The Inverse System Method Applied to the Derivation of Power System Non—linear Control Laws

    Institute of Scientific and Technical Information of China (English)

    DonghaiLI; XuezhiJIANG; 等

    1997-01-01

    The differential geometric method has been applied to a series of power system non-linear control problems effectively.However a set of differential equations must be solved for obtaining the required diffeomorphic transformation.Therefore the derivation of control laws is very complicated.In fact because of the specificity of power system models the required diffeomorphic transformation may be obtained directly,so it is unnecessary to solve a set of differential equations.In addition inverse system method is equivalent to differential geometric method in reality and not limited to affine nonlinear systems,Its physical meaning is able to be viewed directly and its deduction needs only algebraic operation and derivation,so control laws can be obtained easily and the application to engineering is very convenient.Authors of this paper take steam valving control of power system as a typical case to be studied.It is demonstrated that the control law deduced by inverse system method is just the same as one by differential geometric method.The conclusion will simplify the control law derivations of steam valving,excitation,converter and static var compensator by differential geometric method and may be suited to similar control problems in other areas.

  6. The Causal Connection Between Disc and Power-Law Variability in Hard State Black Hole X-Ray Binaries

    Science.gov (United States)

    Uttley, P.; Wilkinson, T.; Cassatella, P.; Wilms, J.; Pottschimdt, K.; Hanke, M.; Boeck, M.

    2010-01-01

    We use the XMM-Newton EPIC-pn instrument in timing mode to extend spectral time-lag studies of hard state black hole X-ray binaries into the soft X-ray band. \\Ve show that variations of the disc blackbody emission substantially lead variations in the power-law emission, by tenths of a second on variability time-scales of seconds or longer. The large lags cannot be explained by Compton scattering but are consistent with time-delays due to viscous propagation of mass accretion fluctuations in the disc. However, on time-scales less than a second the disc lags the power-law variations by a few ms, consistent with the disc variations being dominated by X-ray heating by the power-law, with the short lag corresponding to the light-travel time between the power-law emitting region and the disc. Our results indicate that instabilities in the accretion disc are responsible for continuum variability on time-scales of seconds or longer and probably also on shorter time-scales.

  7. Theories of Power, Poverty, and Law: In Commemoration of the Contributions of Peter Bachrach--Power, Law, and Final Thoughts: The Contributions of Peter Bachrach

    Science.gov (United States)

    Schneider, Elizabeth M.

    2010-01-01

    I am pleased to be part of this symposium to celebrate the life and work of Peter Bachrach. Although my focus is the relevance of Peter's ideas of power to law, I want to begin with some personal comments as well as raise some final thoughts, drawing on others' contributions. Like so many of Peter's other students, I adored him. Peter's joy in…

  8. Power law of distribution of emergency situations on main gas pipeline

    Science.gov (United States)

    Voronin, K. S.; Akulov, K. A.

    2018-05-01

    The article presents the results of the analysis of emergency situations on a main gas pipeline. A power law of distribution of emergency situations is revealed. The possibility of conducting further scientific research to ensure the predictability of emergency situations on pipelines is justified.

  9. Theoretical scaling law of coronal magnetic field and electron power-law index in solar microwave burst sources

    Science.gov (United States)

    Huang, Y.; Song, Q. W.; Tan, B. L.

    2018-04-01

    It is first proposed a theoretical scaling law respectively for the coronal magnetic field strength B and electron power-law index δ versus frequency and coronal height in solar microwave burst sources. Based on the non-thermal gyro-synchrotron radiation model (Ramaty in Astrophys. J. 158:753, 1969), B and δ are uniquely solved by the observable optically-thin spectral index and turnover (peak) frequency, the other parameters (plasma density, temperature, view angle, low and high energy cutoffs, etc.) are relatively insensitive to the calculations, thus taken as some typical values. Both of B and δ increase with increasing of radio frequency but with decreasing of coronal height above photosphere, and well satisfy a square or cubic logarithmic fitting.

  10. Active Power Filter DC Bus Voltage Piecewise Reaching Law Variable Structure Control

    OpenAIRE

    Liu, Baolian; Ding, Zujun; Zhao, Huanyu; Jin, Defei

    2014-01-01

    The DC bus voltage stability control is one key technology to ensure that Active Power Filter (APF) operates stably. The external disturbances such as power grid and load fluctuation and the system parameters changing may affect the stability of APF DC bus voltage and the normal operation of APF. The mathematical model of DC bus voltage is established according to power balance principle and a DC bus voltage piecewise reaching law variable structure control algorithm is proposed to solve the ...

  11. Sliding friction in the hydrodynamic lubrication regime for a power-law fluid

    International Nuclear Information System (INIS)

    Warren, P B

    2017-01-01

    A scaling analysis is undertaken for the load balance in sliding friction in the hydrodynamic lubrication regime, with a particular emphasis on power-law shear-thinning typical of a structured liquid. It is argued that the shear-thinning regime is mechanically unstable if the power-law index n   <  1/2, where n is the exponent that relates the shear stress to the shear rate. Consequently the Stribeck (friction) curve should be discontinuous, with possible hysteresis. Further analysis suggests that normal stress and flow transience (stress overshoot) do not destroy this basic picture, although they may provide stabilising mechanisms at higher shear rates. Extensional viscosity is also expected to be insignificant unless the Trouton ratio is large. A possible application to shear thickening in non-Brownian particulate suspensions is indicated. (paper)

  12. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity.

    Science.gov (United States)

    Tippett, Michael K; Cohen, Joel E

    2016-02-29

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related.

  13. Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

    Science.gov (United States)

    Tippett, Michael K.; Cohen, Joel E.

    2016-01-01

    Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from ‘outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954–2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related. PMID:26923210

  14. The quick convolution of galaxy profiles, with application to power-law intensity distributions

    International Nuclear Information System (INIS)

    Bailey, M.E.; Sparks, W.B.

    1983-01-01

    The two-dimensional convolution of a circularly symmetric galaxy model with a Gaussian point-spread function of dispersion σ reduces to a single integral. This is solved analytically for models with power-law intensity distributions and results are given which relate the apparent core radius to σ and the power-law index k. The convolution integral is also simplified for the case of a point-spread function corresponding to a circular aperture. Models of galactic nuclei with stellar density cusps can only be distinguished from alternatives with small core radii if both the brightness and seeing profiles are measured accurately. The results are applied to data on the light distribution at the Galactic Centre. (author)

  15. A non-coulombic effective power-law potential for the heavy quarkoniums

    International Nuclear Information System (INIS)

    Barik, N.; Jena, S.N.

    1980-01-01

    An effective power-law potential of the form V(r) = 6.08 r 0 sup(.) 106 - 6.41 is found to describe satisfactorily the gross features of the mass spectra and the leptonic width ratios of the cc and bb systems in a flavour-independent manner. (orig.)

  16. Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

    Directory of Open Access Journals (Sweden)

    Radovan Stojanovic

    2013-01-01

    Full Text Available A fully digital photoplethysmographic (PPG sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2. The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2. N-LEDs configuration is proposed for multichannel SpO2 measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

  17. Design of an oximeter based on LED-LED configuration and FPGA technology.

    Science.gov (United States)

    Stojanovic, Radovan; Karadaglic, Dejan

    2013-01-04

    A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (S(p)O(2)). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (S(p)O(2)). N-LEDs configuration is proposed for multichannel S(p)O(2) measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

  18. Breaking the power law: Multiscale simulations of self-ion irradiated tungsten

    Science.gov (United States)

    Jin, Miaomiao; Permann, Cody; Short, Michael P.

    2018-06-01

    The initial stage of radiation defect creation has often been shown to follow a power law distribution at short time scales, recently so with tungsten, following many self-organizing patterns found in nature. The evolution of this damage, however, is dominated by interactions between defect clusters, as the coalescence of smaller defects into clusters depends on the balance between transport, absorption, and emission to/from existing clusters. The long-time evolution of radiation-induced defects in tungsten is studied with cluster dynamics parameterized with lower length scale simulations, and is shown to deviate from a power law size distribution. The effects of parameters such as dose rate and total dose, as parameters affecting the strength of the driving force for defect evolution, are also analyzed. Excellent agreement is achieved with regards to an experimentally measured defect size distribution at 30 K. This study provides another satisfactory explanation for experimental observations in addition to that of primary radiation damage, which should be reconciled with additional validation data.

  19. Power-law photoluminescence decay in indirect gap quantum dots

    Czech Academy of Sciences Publication Activity Database

    Menšík, Miroslav; Král, Karel

    2013-01-01

    Roč. 111, November (2013), s. 170-174 ISSN 0167-9317 R&D Projects: GA MŠk(CZ) OC10007; GA MŠk LH12186; GA MŠk LH12236; GA ČR(CZ) GAP205/10/2280 Institutional support: RVO:61389013 ; RVO:68378271 Keywords : quantum dots * indirect gap transition * power-law photoluminescence decay Subject RIV: BM - Solid Matter Physics ; Magnetism; BE - Theoretical Physics (FZU-D) Impact factor: 1.338, year: 2013

  20. Implantable wireless powered light emitting diode (LED) for near-infrared photoimmunotherapy: device development and experimental assessment in vitro and in vivo.

    Science.gov (United States)

    Nakajima, Kohei; Kimura, Toshihiro; Takakura, Hideo; Yoshikawa, Yasuo; Kameda, Atsushi; Shindo, Takayuki; Sato, Kazuhide; Kobayashi, Hisataka; Ogawa, Mikako

    2018-04-13

    The aim of this study was to develop and assess a novel implantable, wireless-powered, light-emitting diode (LED) for near-infrared photoimmunotherapy (NIR-PIT). NIR-PIT is a recently developed cancer therapy that uses NIR light and antibody-photosensitizer conjugates and is able to induce cancer-specific cell death. Due to limited light penetration depth it is currently unable to treat tumors in deep tissues. Use of implanted LED might potentially overcome this limitation. The wireless LED system was able to emit NIR light up to a distance of 20 cm from the transmitter coil by using low magnetic fields as compliant with limits for use in humans. Results indicated that the LED system was able to kill tumor cells in vitro and to suppress tumor growth in implanted tumor-bearing mice. Results indicated that the proposed implantable wireless LED system was able to suppress tumor growth in vivo . These results are encouraging as wireless LED systems such as the one here developed might be a possible solution to treat tumors in deep regions in humans. Further research in this area would be important. An implantable LED system was developed. It consisted of a LED capsule including two LED sources and a receiver coil coupled with an external coil and power source. Wireless power transmission was guaranteed by using electromagnetic induction. The system was tested in vitro by using EGFR-expressing cells and HER2-expressing cells. The system was also tested in vivo in tumor-bearing mice.

  1. Experimental evaluation of the MIT-SNL period-generated minimum time control laws for the rapid adjustment of reactor power

    International Nuclear Information System (INIS)

    Bernard, J.A.; Kwok, K.S.; Menadier, P.T.; Thome, F.V.; Wyant, F.J.

    1987-01-01

    The rapid adjustment of reactor neutronic power has recently been achieved by developing control laws that determine the actuator mechanism velocity necessary to produce a specified reactor period. Designated as the 'MIT-SNL Period-Generated Minimum Time Control Laws,' these relations are closed-form expressions of general applicability. In particular, if there is no limitation on the available rate of change of reactivity, these laws can be used to achieve virtually any desired power profile including time optimal ones. The innovative aspect of these laws is that the rate of change of reactivity rather than the reactivity itself is used as the control signal. For example, relative to a time-optimal response, these laws function by altering the rate of change of reactivity so that the instantaneous period is stepped from infinity to its minimum allowed value, held at that value until the desired power level is attained, and then stepped back to infinity. The response is time-optimal because the power adjustment is continuously made at the maximum allowed rate

  2. Power-law Growth and Punctuated Equilibrium Dynamics in Water Resources Systems

    Science.gov (United States)

    Parolari, A.; Katul, G. G.; Porporato, A. M.

    2015-12-01

    The global rise in population-driven water scarcity and recent appreciation of strong dynamic coupling between human and natural systems has called for new approaches to predict the future sustainability of regional and global water resources systems. The dynamics of coupled human-water systems are driven by a complex set of social, environmental, and technological factors. Present projections of water resources systems range from a finite carrying capacity regulated by accessible freshwater, or `peak renewable water,' to punctuated evolution with new supplied and improved efficiency gained from technological and social innovation. However, these projections have yet to be quantified from observations or in a comprehensive theoretical framework. Using data on global water withdrawals and storage capacity of regional water supply systems, non-trivial dynamics are identified in water resources systems development over time, including power-law growth and punctuated equilibria. Two models are introduced to explain this behavior: (1) a delay differential equation and (2) a power-law with log-periodic oscillations, both of which rely on past conditions (or system memory) to describe the present rate of growth in the system. In addition, extension of the first model demonstrates how system delays and punctuated equilibria can emerge from coupling between human population growth and associated resource demands. Lastly, anecdotal evidence is used to demonstrate the likelihood of power-law growth in global water use from the agricultural revolution 3000 BC to the present. In a practical sense, the presence of these patterns in models with delayed oscillations suggests that current decision-making related to water resources development results from the historical accumulation of resource use decisions, technological and social changes, and their consequences.

  3. Brief review of Planck law

    International Nuclear Information System (INIS)

    Zamora Carranza, M.

    2001-01-01

    This paper presents a brief review of the scientific events which led to the determination of the law of radiation and the quantisation of energy by Max Planck. From the separation of sunlight by Newton to the reasons which led Planck to quantised the energy of an oscillator. I discuss the theoretical and experimental difficulties which scientists overcame to derive the law of heat radiation. (Author) 6 refs

  4. Convective hydromagnetic instabilities of a power-law liquid saturating a porous medium: Flux conditions

    Science.gov (United States)

    Chahtour, C.; Ben Hamed, H.; Beji, H.; Guizani, A.; Alimi, W.

    2018-01-01

    We investigate how an external imposed magnetic field affects thermal instability in a horizontal shallow porous cavity saturated by a non-Newtonian power-law liquid. The magnetic field is assumed to be constant and parallel to the gravity. A uniform heat flux is applied to the horizontal walls of the layer while the vertical walls are adiabatic. We use linear stability analysis to find expressions for the critical Rayleigh number as a function of the power-law index and the intensity of the magnetic field. We use nonlinear parallel flow theory to find some explicit solutions of the problem, and we use finite difference numerical simulations to solve the full nonlinear equations. We show how the presence of magnetic field alters the known hydrodynamical result of Newtonian flows and power-law flows and how it causes the presence of subcritical finite amplitude convection for both pseudoplastic and dilatant fluids. We also show that in the limit of very strong magnetic field, the dissipation of energy by Joule effect dominates the dissipation of energy by shear stress and gives to the liquid an inviscid character.

  5. Study and Implementation of White Power-LED Based Indoor Lighting Application for the Healthcare Sector

    Science.gov (United States)

    Chakraborty, A.; Ganguly, R.

    With the current technological growth in the field of device fabrication, white power-LED's are available for solid state lighting applications. This is a paradigm shift from electrical lighting to electronic lighting. The implemented systems are showing some promise by saving a considerable amount of energy as well as providing a good and acceptable illumination level. However, the `useful life' of such devices is an important parameter. If the proper device is not chosen, the desired reliability and performance will not be obtained. In the present work, different parameters associated with reliability of such LED's are studied. Four different varieties of LED's are put to test the `useful life' as per IESNA LM 79 standard. From the results obtained, the proper LED is chosen for further application. Subsequently, lighting design is done for a hospital waiting room (indoor application) with 24 × 7 lighting requirements for replacement of existing CFLs there. The calculations show that although the initial cost is higher for LED based lighting, yet the savings on energy and replacement of the lamp results in a payback time of less than a year.

  6. Modeling the complexity of acoustic emission during intermittent plastic deformation: Power laws and multifractal spectra.

    Science.gov (United States)

    Kumar, Jagadish; Ananthakrishna, G

    2018-01-01

    Scale-invariant power-law distributions for acoustic emission signals are ubiquitous in several plastically deforming materials. However, power-law distributions for acoustic emission energies are reported in distinctly different plastically deforming situations such as hcp and fcc single and polycrystalline samples exhibiting smooth stress-strain curves and in dilute metallic alloys exhibiting discontinuous flow. This is surprising since the underlying dislocation mechanisms in these two types of deformations are very different. So far, there have been no models that predict the power-law statistics for discontinuous flow. Furthermore, the statistics of the acoustic emission signals in jerky flow is even more complex, requiring multifractal measures for a proper characterization. There has been no model that explains the complex statistics either. Here we address the problem of statistical characterization of the acoustic emission signals associated with the three types of the Portevin-Le Chatelier bands. Following our recently proposed general framework for calculating acoustic emission, we set up a wave equation for the elastic degrees of freedom with a plastic strain rate as a source term. The energy dissipated during acoustic emission is represented by the Rayleigh-dissipation function. Using the plastic strain rate obtained from the Ananthakrishna model for the Portevin-Le Chatelier effect, we compute the acoustic emission signals associated with the three Portevin-Le Chatelier bands and the Lüders-like band. The so-calculated acoustic emission signals are used for further statistical characterization. Our results show that the model predicts power-law statistics for all the acoustic emission signals associated with the three types of Portevin-Le Chatelier bands with the exponent values increasing with increasing strain rate. The calculated multifractal spectra corresponding to the acoustic emission signals associated with the three band types have a maximum

  7. Numerical simulation of heat transfer in power law fluid flow through a stenosed artery

    Science.gov (United States)

    Talib, Amira Husni; Abdullah, Ilyani

    2017-11-01

    A numerical study of heat transfer in a power law fluid is investigated in this paper. The blood flow is treated as power law fluid with a presence of cosine shaped stenosis. This study reveals the effect of stenosis on the heat transfer and velocity of blood flowing in the constricted artery. The governing and energy equations are formulated in a cylindrical coordinate system. Hence, the set of equations and boundary conditions are solved numerically by Marker and Cell (MAC) method. The graphical result shows the profile of blood temperature is increased while the blood velocity is decreased at the critical height of stenosis.

  8. The european union as subjects of law

    Directory of Open Access Journals (Sweden)

    Fila R.

    2012-10-01

    Full Text Available At the international level it is recognized that development and progress of the new and unique international organization – European Union – is one of the appropriate form of the international organization’s integration. Although European Union was establish as international economic organization, it has gradually integrated the various “best practices” ideas from different governmental systems. Encouragement and motives for cooperation of Member states indicate that member states give more competences of government to the international organization’s institutes. Wherewith, it is observed that the economic and political internationalization has led to disappearance of integrity of territory of member states. The above mentioned opinion is not based on research of the European Union as international organization from standpoint of international law, but from standpoint of theory law – could give juridical estimate regarding executive power in European Union and who could define particular source and entity of administrative law of European Union.

  9. The Transient Elliptic Flow of Power-Law Fluid in Fractal Porous Media

    Institute of Scientific and Technical Information of China (English)

    宋付权; 刘慈群

    2002-01-01

    The steady oil production and pressure distribution formulae of vertically fractured well for power-law non-Newtonian fluid were derived on the basis of the elliptic flow model in fractal reservoirs. The corresponding transient flow in fractal reservoirs was studied by numerical differentiation method: the influence of fractal index to transient pressure of vertically fractured well was analyzed. Finally the approximate analytical solution of transient flow was given by average mass conservation law. The study shows that using elliptic flow method to analyze the flow of vertically fractured well is a simple method.

  10. Powerful subjects of tax law enforcement

    Directory of Open Access Journals (Sweden)

    Igor Dementyev

    2017-01-01

    Full Text Available УДК 342.6The subject. Competence of government bodies and their officials in the sphere of application of the tax law is considered in the article.The purpose of research is to determine the ratio of tax enforcement and application of the tax law, as well as the relationship between the concepts “party of tax enforcement” and “participant of tax legal relations”.Main results and scope of their application. The circle of participants of tax legal relations is broader than the circle of parties of tax law enforcement. The participants of tax legal relations are simultaneously the subjects of tax law, because they realize their tax status when enter into the tax relationships. The tax and customs authorities are the undoubted parties of the tax law enforcement.Although the financial authorities at all levels of government are not mentioned by article 9 of the Tax Code of the Russian Federation as participants of tax relations, they are parties of tax enforcement, because they make the agreement for deferment or installment payment of regional and local taxes.Scope of application. Clarification of participants of tax legal relations and determination of their mutual responsibility is essential to effective law enforcement.Conclusion. It was concluded that the scope tax law enforcement is tax proceedings, not administrative proceedings, civil (arbitration proceedings or enforcement proceedings.The application of the tax law is carried out not only in the form of tax relations, but also in relations of other branches of law.

  11. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

    2011-01-01

    , modulation schemes, LEDs and LED driving conditions are analyzed. A prototype radial mode PT optimized for ZVS (Zero Voltage Switching) is designed. FEM (Final Element Method) and measurements validates the PT design. A prototype PT based AC/DC converter operating from european mains is proposed......This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits...

  12. Power Law Distributions in Two Community Currencies

    Science.gov (United States)

    Kichiji, N.; Nishibe, M.

    2007-07-01

    The purpose of this paper is to highlight certain newly discovered social phenomena that accord with Zipf's law, in addition to the famous natural and social phenomena including word frequencies, earthquake magnitude, city size, income1 etc. that are already known to follow it. These phenomena have recently been discovered within the transaction amount (payments or receipts) distributions within two different Community Currencies (CC) that had been initiated as social experiments. One is a local CC circulating in a specific geographical area, such as a town. The other is a virtual CC used among members who belong to a certain community of interest (COI) on the Internet. We conducted two empirical studies to estimate the economic vitalization effects they had on their respective local economies. The results we found were that the amount of transactions (payments and receipts) of the two CCs was distributed according to a power-law distribution with a unity rank exponent. In addition, we found differences between the two CCs with regard to the shapes of their distribution over a low-transaction range. The result may originate from the difference in methods of issuing CCs or in the magnitudes of the minimum-value unit; however, this result calls for further investigation.

  13. Graph Structure in Three National Academic Webs: Power Laws with Anomalies.

    Science.gov (United States)

    Thelwall, Mike; Wilkinson, David

    2003-01-01

    Explains how the Web can be modeled as a mathematical graph and analyzes the graph structures of three national university publicly indexable Web sites from Australia, New Zealand, and the United Kingdom. Topics include commercial search engines and academic Web link research; method-analysis environment and data sets; and power laws. (LRW)

  14. Mathematical analysis of the global dynamics of a power law model ...

    African Journals Online (AJOL)

    We analyze a mathematical power law model that describes HIV infection of CD4+ T cells. We report that the number of critical points depends on , where is a positive integer. We show that for any positive integer the infection – free equilibrium is asymptotically stable if the reproduction number R0 1.

  15. Analytical Solution of Unsteady Gravity Flows of A Power-Law Fluid ...

    African Journals Online (AJOL)

    We present an analytical study of unsteady non-linear rheological effects of a power-law fluid under gravity. The fluid flows through a porous medium. The governing equations are derived and similarity solutions are determined. The results show the existence of traveling waves. It is assumed that the viscosity is temperature ...

  16. Universal power-law diet partitioning by marine fish and squid with surprising stability–diversity implications

    Science.gov (United States)

    Rossberg, Axel G.; Farnsworth, Keith D.; Satoh, Keisuke; Pinnegar, John K.

    2011-01-01

    A central question in community ecology is how the number of trophic links relates to community species richness. For simple dynamical food-web models, link density (the ratio of links to species) is bounded from above as the number of species increases; but empirical data suggest that it increases without bounds. We found a new empirical upper bound on link density in large marine communities with emphasis on fish and squid, using novel methods that avoid known sources of bias in traditional approaches. Bounds are expressed in terms of the diet-partitioning function (DPF): the average number of resources contributing more than a fraction f to a consumer's diet, as a function of f. All observed DPF follow a functional form closely related to a power law, with power-law exponents independent of species richness at the measurement accuracy. Results imply universal upper bounds on link density across the oceans. However, the inherently scale-free nature of power-law diet partitioning suggests that the DPF itself is a better defined characterization of network structure than link density. PMID:21068048

  17. The law governing power generation and the atomic energy law in Japan, with special regard to the current situation in the energy sector

    International Nuclear Information System (INIS)

    Fujiwara, J.

    1984-01-01

    This contribution characterises Japanese legislation on power generation and supply, goes into detail with regard to the current Atomic Energy Law within the framework of the overall legal concept governing power supply, and presents an outlook on future developments. A table summarizes the main problems in this field. (orig./HSCH) [de

  18. Determination of the Real Loss of Power for a Condensing and a Backpressure Turbine by Means of Second Law Analysis

    Directory of Open Access Journals (Sweden)

    Henrik Holmberg

    2009-10-01

    Full Text Available All real processes generate entropy and the power/exergy loss is usually determined by means of the Gouy-Stodola law. If the system only exchanges heat at the environmental temperature, the Gouy-Stodola law gives the correct loss of power. However, most industrial processes exchange heat at higher or lower temperatures than the actual environmental temperature. When calculating the real loss of power in these cases, the Gouy-Stodola law does not give the correct loss if the actual environmental temperature is used. The first aim of this paper is to show through simple steam turbine examples that the previous statement is true. The second aim of the paper is to define the effective temperature to calculate the real power loss of the system with the Gouy-Stodola law, and to apply it to turbine examples. Example calculations also show that the correct power loss can be defined if the effective temperature is used instead of the real environmental temperature.

  19. Accuracy analysis of measurements on a stable power-law distributed series of events

    International Nuclear Information System (INIS)

    Matthews, J O; Hopcraft, K I; Jakeman, E; Siviour, G B

    2006-01-01

    We investigate how finite measurement time limits the accuracy with which the parameters of a stably distributed random series of events can be determined. The model process is generated by timing the emigration of individuals from a population that is subject to deaths and a particular choice of multiple immigration events. This leads to a scale-free discrete random process where customary measures, such as mean value and variance, do not exist. However, converting the number of events occurring in fixed time intervals to a 1-bit 'clipped' process allows the construction of well-behaved statistics that still retain vestiges of the original power-law and fluctuation properties. These statistics include the clipped mean and correlation function, from measurements of which both the power-law index of the distribution of events and the time constant of its fluctuations can be deduced. We report here a theoretical analysis of the accuracy of measurements of the mean of the clipped process. This indicates that, for a fixed experiment time, the error on measurements of the sample mean is minimized by an optimum choice of the number of samples. It is shown furthermore that this choice is sensitive to the power-law index and that the approach to Poisson statistics is dominated by rare events or 'outliers'. Our results are supported by numerical simulation

  20. MHD free convection flow of a non-Newtonian power-law fluid over ...

    African Journals Online (AJOL)

    ... flow have been presented for various parameters such as Prandtl number, flow behavior index (n), porous plate parameter and magnetic parameter. The local Nusselt number and skin friction coefficient is also presented graphically. Keywords: Magnetohydrodynamic flow; free convection flow; Non-Newtonian power-law

  1. Harmonics Monitoring Survey on LED Lamps

    Directory of Open Access Journals (Sweden)

    Abdelrahman Ahmed Akila

    2017-03-01

    Full Text Available Light Emitting Diode (LED lamps are being increasingly used in many applications. These LED lamps operate using a driver, which is a switching device. Hence, LED lamps will be a source of harmonics in the power system. These harmonics if not well treated, may cause severe performance and operational problems. In this paper, harmonics (amplitude and phase angles generated by both LED lamps and conventional fluorescent lamps will be studied practically. Then they will be analyzed and evaluated. Compared to each other harmonics generated by both LED and conventional florescent lamps, self mitigation may occur based on the phase angle of these harmonics. All data will be measured using power analyzer and will be done on a sample of actual lamps.

  2. Power-law tails and non-Markovian dynamics in open quantum systems: An exact solution from Keldysh field theory

    Science.gov (United States)

    Chakraborty, Ahana; Sensarma, Rajdeep

    2018-03-01

    The Born-Markov approximation is widely used to study the dynamics of open quantum systems coupled to external baths. Using Keldysh formalism, we show that the dynamics of a system of bosons (fermions) linearly coupled to a noninteracting bosonic (fermionic) bath falls outside this paradigm if the bath spectral function has nonanalyticities as a function of frequency. In this case, we show that the dissipative and noise kernels governing the dynamics have distinct power-law tails. The Green's functions show a short-time "quasi"-Markovian exponential decay before crossing over to a power-law tail governed by the nonanalyticity of the spectral function. We study a system of bosons (fermions) hopping on a one-dimensional lattice, where each site is coupled linearly to an independent bath of noninteracting bosons (fermions). We obtain exact expressions for the Green's functions of this system, which show power-law decay ˜|t - t'|-3 /2 . We use these to calculate the density and current profile, as well as unequal-time current-current correlators. While the density and current profiles show interesting quantitative deviations from Markovian results, the current-current correlators show qualitatively distinct long-time power-law tails |t - t'|-3 characteristic of non-Markovian dynamics. We show that the power-law decays survive in the presence of interparticle interaction in the system, but the crossover time scale is shifted to larger values with increasing interaction strength.

  3. SUBSTANTIAL EXCEPTIONS AND (DELIMITATIONS OF THE POWERS OF THE JUDGES ON CIVIL PROCEDURAL LAW

    Directory of Open Access Journals (Sweden)

    Igor Raatz

    2017-08-01

    Full Text Available This essay aims to unveil the role of the substantial exceptions on delimiting the powers of the judges on civil procedural law, especially regarding the ex officio judicial activity. This way, under a phenomenological method and based on a vision of guarantee of rights on procedural law, the article offers a brief explanation of the question concerning the content of the object under litigation and its role of (delimiting the powers of the judges. The work hypothesis is the addition of the substantial exceptions among the content of the object under litigation, along with the claim itself and the cause of action. The results lie on the premise that, by the substantial exceptions, the defendant extends the object under litigation – which is formed dynamically on civil procedure. The conclusion points towards the idea that the substantial exceptions act in a way of limiting the ex officio judicial activity on civil procedural law

  4. Beta Function Quintessence Cosmological Parameters and Fundamental Constants I: Power and Inverse Power Law Dark Energy Potentials

    Science.gov (United States)

    Thompson, Rodger I.

    2018-04-01

    This investigation explores using the beta function formalism to calculate analytic solutions for the observable parameters in rolling scalar field cosmologies. The beta function in this case is the derivative of the scalar ϕ with respect to the natural log of the scale factor a, β (φ )=d φ /d ln (a). Once the beta function is specified, modulo a boundary condition, the evolution of the scalar ϕ as a function of the scale factor is completely determined. A rolling scalar field cosmology is defined by its action which can contain a range of physically motivated dark energy potentials. The beta function is chosen so that the associated "beta potential" is an accurate, but not exact, representation of the appropriate dark energy model potential. The basic concept is that the action with the beta potential is so similar to the action with the model potential that solutions using the beta action are accurate representations of solutions using the model action. The beta function provides an extra equation to calculate analytic functions of the cosmologies parameters as a function of the scale factor that are that are not calculable using only the model action. As an example this investigation uses a quintessence cosmology to demonstrate the method for power and inverse power law dark energy potentials. An interesting result of the investigation is that the Hubble parameter H is almost completely insensitive to the power of the potentials and that ΛCDM is part of the family of quintessence cosmology power law potentials with a power of zero.

  5. MHD axisymmetric flow of power-law fluid over an unsteady stretching sheet with convective boundary conditions

    Directory of Open Access Journals (Sweden)

    Jawad Ahmed

    Full Text Available This paper examines the boundary layer flow and heat transfer characteristic in power law fluid model over unsteady radially stretching sheet under the influence of convective boundary conditions. A uniform magnetic field is applied transversely to the direction of the flow. The governing time dependent nonlinear boundary layer equations are reduced into nonlinear ordinary differential equations with the help of similarity transformations. The transformed coupled ordinary differential equations are then solved analytically by homotopy analysis method (HAM and numerically by shooting procedure. Effects of various governing parameters like, power law index n, magnetic parameter M, unsteadiness A, suction/injection S, Biot number γ and generalized Prandtl number Pr on velocity, temperature, local skin friction and the local Nusselt number are studied and discussed. It is found from the analysis that the magnetic parameter diminishes the velocity profile and the corresponding thermal boundary layer thickness. Keywords: Axisymmetric flow, Power law fluid, Unsteady stretching, Convective boundary conditions

  6. Power laws reveal phase transitions in landscape controls of fire regimes

    Science.gov (United States)

    Donald McKenzie; Maureen C. Kennedy

    2012-01-01

    Understanding the environmental controls on historical wildfires, and how they changed across spatial scales, is difficult because there are no surviving explicit records of either weather or vegetation (fuels). Here we show how power laws associated with fire-event time series arise in limited domains of parameters that represent critical transitions in the controls...

  7. Asymptotic expansion of unsteady gravity flow of a power-law fluid ...

    African Journals Online (AJOL)

    We present a paper on the asymptotic expansion of unsteady non-linear rheological effects of a power-law fluid under gravity. The fluid flows through a porous medium. The asymptotic expansion is employed to obtain solution of the nonlinear problem. The results show the existence of traveling waves. It is assumed that the ...

  8. Focus-based filtering + clustering technique for power-law networks with small world phenomenon

    Science.gov (United States)

    Boutin, François; Thièvre, Jérôme; Hascoët, Mountaz

    2006-01-01

    Realistic interaction networks usually present two main properties: a power-law degree distribution and a small world behavior. Few nodes are linked to many nodes and adjacent nodes are likely to share common neighbors. Moreover, graph structure usually presents a dense core that is difficult to explore with classical filtering and clustering techniques. In this paper, we propose a new filtering technique accounting for a user-focus. This technique extracts a tree-like graph with also power-law degree distribution and small world behavior. Resulting structure is easily drawn with classical force-directed drawing algorithms. It is also quickly clustered and displayed into a multi-level silhouette tree (MuSi-Tree) from any user-focus. We built a new graph filtering + clustering + drawing API and report a case study.

  9. Numerical analysis of the transient conjugated heat transfer in a circular duct with a power-law fluid

    Energy Technology Data Exchange (ETDEWEB)

    Luna, N. [Secretaria de Energia, Direccion de Operacion Petrolera, Mexico DF (Mexico); Mendez, F. [UNAM, Facultad de Ingenieria, Mexico DF (Mexico); Bautista, O. [ITESM, Division de Ingenieria y Arquitectura, Mexico DF (Mexico)

    2005-05-01

    We treat numerically in this paper, the transient analysis of a conjugated heat transfer process in the thermal entrance region of a circular tube with a fully developed laminar power-law fluid flow. We apply the quasi-steady approximation for the power-law fluid, identifying the suitable time scales of the process. Thus, the energy equation in the fluids is solved analytically using the well-known integral boundary layer technique. This solution is coupled to the transient energy equation for the solid where the transverse and longitudinal heat conduction effects are taken into account. The numerical results for the temporal evolution of the average temperature of the tube wall, {theta}{sub av,} is plotted for different nondimensional parameters such as conduction parameter, {alpha}, the aspect ratios of the tube, {epsilon} and {epsilon}{sub 0} and the index of power-law fluid, n. (orig.)

  10. The relationship between randomness and power-law distributed move lengths in random walk algorithms

    Science.gov (United States)

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2014-05-01

    Recently, we proposed a new random walk algorithm, termed the REV algorithm, in which the agent alters the directional rule that governs it using the most recent four random numbers. Here, we examined how a non-bounded number, i.e., "randomness" regarding move direction, was important for optimal searching and power-law distributed step lengths in rule change. We proposed two algorithms: the REV and REV-bounded algorithms. In the REV algorithm, one of the four random numbers used to change the rule is non-bounded. In contrast, all four random numbers in the REV-bounded algorithm are bounded. We showed that the REV algorithm exhibited more consistent power-law distributed step lengths and flexible searching behavior.

  11. High Efficiency Driving Electronics for General Illumination LED Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Anand

    2012-10-31

    New generation of standalone LED driver platforms developed, which are more efficient These LED Drivers are more efficient (≥90%), smaller in size ( 0.15 in3/watt), lower in cost ( 12 cents/watt in high volumes in millions of units). And these products are very reliable having an operating life of over 50,000 hours. This technology will enable growth of LED light sources in the use. This will also help in energy saving and reducing total life cycle cost of LED units. Two topologies selected for next generation of LED drivers: 1) Value engineered single stage Flyback topology. This is suitable for low powered LED drivers up to 50W power. 2) Two stage boost power factor correction (PFC) plus LLC half bridge platform for higher powers. This topology is suitable for 40W to 300W LED drivers. Three new product platforms were developed to cover a wide range of LED drivers: 1) 120V 40W LED driver, 2) Intellivolt 75W LED driver, & 3) Intellivolt 150W LED driver. These are standalone LED drivers for rugged outdoor lighting applications. Based on these platforms number of products are developed and successfully introduced in the market place meeting key performance, size and cost goals.

  12. Non-Darcy Free Convection of Power-Law Fluids Over a Two-Dimensional Body Embedded in a Porous Medium

    KAUST Repository

    El-Amin, Mohamed

    2010-11-27

    A boundary layer analysis was presented to study the non-Darcy-free convection of a power-law fluid over a non-isothermal two-dimensional body embedded in a porous medium. The Ostwald-de Waele power-law model was used to characterize the non-Newtonian fluid behavior. Similarity solutions were obtained with variations in surface temperature or surface heat flux. In view of the fact that most of the non-Newtonian fluids have large Prandtl numbers, this study was directed toward such fluids. The effects of the porous medium parameters, k1 and k2, body shape parameter, m, and surface thermal variations parameter, p, as well as the power-law index, n, were examined. © 2010 Springer Science+Business Media B.V.

  13. Non-Darcy Free Convection of Power-Law Fluids Over a Two-Dimensional Body Embedded in a Porous Medium

    KAUST Repository

    El-Amin, Mohamed; Sun, Shuyu; El-Ameen, M. A.; Jaha, Y. A.; Gorla, Rama Subba Reddy

    2010-01-01

    A boundary layer analysis was presented to study the non-Darcy-free convection of a power-law fluid over a non-isothermal two-dimensional body embedded in a porous medium. The Ostwald-de Waele power-law model was used to characterize the non-Newtonian fluid behavior. Similarity solutions were obtained with variations in surface temperature or surface heat flux. In view of the fact that most of the non-Newtonian fluids have large Prandtl numbers, this study was directed toward such fluids. The effects of the porous medium parameters, k1 and k2, body shape parameter, m, and surface thermal variations parameter, p, as well as the power-law index, n, were examined. © 2010 Springer Science+Business Media B.V.

  14. Formulation and experimental evaluation of closed-form control laws for the rapid maneuvering of reactor neutronic power

    International Nuclear Information System (INIS)

    Bernard, J.A.

    1989-09-01

    This report describes both the theoretical development and the experimental evaluation of a novel, robust methodology for the time-optimal adjustment of a reactor's neutronic power under conditions of closed-loop digital control. Central to the approach are the 'MIT-SNL Period-Generated Minimum Time Control Laws' which determine the rate at which reactivity should be changed in order to cause a reactor's neutronic power to conform to a specified trajectory. Using these laws, reactor power can be safely raised by five to seven orders of magnitude in a few seconds. The MIT-SNL laws were developed to facilitate rapid increases of neutronic power on spacecraft reactors operating in an SDI environment. However, these laws are generic and have other applications including the rapid recovery of research and test reactors subsequent to an unanticipated shutdown, power increases following the achievement of criticality on commercial reactors, power adjustments on commercial reactors so as to minimize thermal stress, and automated startups. The work reported here was performed by the Massachusetts Institute of Technology under contract to the Sandia National Laboratories. Support was also provided by the US Department of Energy's Division of University and Industry Programs. The work described in this report is significant in that a novel solution to the problem of time-optimal control of neutronic power was identified, in that a rigorous description of a reactor's dynamics was derived in that the rate of change of reactivity was recognized as the proper control signal, and in that extensive experimental trials were conducted of these newly developed concepts on actual nuclear reactors. 43 refs., 118 figs., 11 tabs

  15. Evidence for intermittency and a truncated power law from highly resolved aphid movement data.

    Science.gov (United States)

    Mashanova, Alla; Oliver, Tom H; Jansen, Vincent A A

    2010-01-06

    Power laws are increasingly used to describe animal movement. Despite this, the use of power laws has been criticized on both empirical and theoretical grounds, and alternative models based on extensions of conventional random walk theory (Brownian motion) have been suggested. In this paper, we analyse a large volume of data of aphid walking behaviour (65,068 data points), which provides a highly resolved dataset to investigate the pattern of movement. We show that aphid movement is intermittent--with alternations of a slow movement with frequent change of direction and a fast, relatively directed movement--and that the fast movement consists of two phases--a strongly directed phase that gradually changes into an uncorrelated random walk. By measuring the mean-squared displacement and the duration of non-stop movement episodes we found that both spatial and temporal aspects of aphid movement are best described using a truncated power law approach. We suggest that the observed spatial pattern arises from the duration of non-stop movement phases rather than from correlations in turning angles. We discuss the implications of these findings for interpreting movement data, such as distinguishing between movement and non-movement, and the effect of the range of data used in the analysis on the conclusions.

  16. Comparative power law analysis of structured breast phantom and patient images in digital mammography and breast tomosynthesis.

    Science.gov (United States)

    Cockmartin, L; Bosmans, H; Marshall, N W

    2013-08-01

    This work characterizes three candidate mammography phantoms with structured background in terms of power law analysis in the low frequency region of the power spectrum for 2D (planar) mammography and digital breast tomosynthesis (DBT). The study was performed using three phantoms (spheres in water, Voxmam, and BR3D CIRS phantoms) on two DBT systems from two different vendors (Siemens Inspiration and Hologic Selenia Dimensions). Power spectra (PS) were calculated for planar projection, DBT projection, and reconstructed images and curve fitted in the low frequency region from 0.2 to 0.7 mm(-1) with a power law function characterized by an exponent β and magnitude κ. The influence of acquisition dose and tube voltage on the power law parameters was first explored. Then power law parameters were calculated from images acquired with the same anode∕filter combination and tube voltage for the three test objects, and compared with each other. Finally, PS curves for automatic exposure controlled acquisitions (anode∕filter combination and tube voltages selected by the systems based on the breast equivalent thickness of the test objects) were compared against PS analysis performed on patient data (for Siemens 80 and for Hologic 48 mammograms and DBT series). Dosimetric aspects of the three test objects were also examined. The power law exponent (β) was found to be independent of acquisition dose for planar mammography but varied more for DBT projections of the sphere-phantom. Systematic increase of tube voltage did not affect β but decreased κ, both in planar and DBT projection phantom images. Power spectra of the BR3D phantom were closer to those of the patients than these of the Voxmam phantom; the Voxmam phantom gave high values of κ compared to the other phantoms and the patient series. The magnitude of the PS curves of the BR3D phantom was within the patient range but β was lower than the average patient value. Finally, PS magnitude for the sphere

  17. Power-Law Template for IR Point Source Clustering

    Science.gov (United States)

    Addison, Graeme E.; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark; Halpern, Mark; Hincks, Adam; Hlozek, Renee; hide

    2011-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217,353,545 and 857 GHz, over angular scales 100 clustered power over the range of angular scales and frequencies considered is well fit by a simple power law of the form C_l\\propto I(sup -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, nu(sup beta) B(nu,T_eff), with a single emissivity index beta = 2.20 +/- 0.07 and effective temperature T_eff= 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha_150-220 = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in Cosmic Microwave Background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  18. Power-Law Template for Infrared Point-Source Clustering

    Science.gov (United States)

    Addison, Graeme E; Dunkley, Joanna; Hajian, Amir; Viero, Marco; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Halpern, Mark; Hincks, Adam D; Hlozek, Renee; hide

    2012-01-01

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 approx clustered power over the range of angular scales and frequencies considered is well fitted by a simple power law of the form C(sup clust)(sub l) varies as l (sub -n) with n = 1.25 +/- 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, ?(sup Beta)B(?, T(sub eff) ), with a single emissivity index Beta = 2.20 +/- 0.07 and effective temperature T(sub eff) = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be alpha(sub 150-220) = 3.68 +/- 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  19. Inertia effects in the laminar radial flow of a power law fluid with an electromagnetic field

    International Nuclear Information System (INIS)

    Chen, C.-K.; Chen, K.-H.; Wu, C.-Y.

    1984-01-01

    An approximate study of the pressure distribution for the radial flow of a non-newtonian (power law) fluid between two parallel disks in the presence of an axial electrical field is obtained by using the momentum and energy integral methods. For a non-newtonian fluid it is shown that the inertia effect must be considered to be significant for the pressure distribution, especially for the power law fluids with n >= 1. Furthermore, it is seen that the inertia effect will also lower the load capacity of the disks. (Auth.)

  20. Power-law neuronal fluctuations in a recurrent network model of parametric working memory.

    Science.gov (United States)

    Miller, Paul; Wang, Xiao-Jing

    2006-02-01

    In a working memory system, persistent activity maintains information in the absence of external stimulation, therefore the time scale and structure of correlated neural fluctuations reflect the intrinsic microcircuit dynamics rather than direct responses to sensory inputs. Here we show that a parametric working memory model capable of graded persistent activity is characterized by arbitrarily long correlation times, with Fano factors and power spectra of neural activity described by the power laws of a random walk. Collective drifts of the mnemonic firing pattern induce long-term noise correlations between pairs of cells, with the sign (positive or negative) and amplitude proportional to the product of the gradients of their tuning curves. None of the power-law behavior was observed in a variant of the model endowed with discrete bistable neural groups, where noise fluctuations were unable to cause long-term changes in rate. Therefore such behavior can serve as a probe for a quasi-continuous attractor. We propose that the unusual correlated fluctuations have important implications for neural coding in parametric working memory circuits.

  1. Converging cylindrical magnetohydrodynamic shock collapse onto a power-law-varying line current

    KAUST Repository

    Mostert, W.; Pullin, D. I.; Samtaney, Ravi; Wheatley, V.

    2016-01-01

    We investigate the convergence behaviour of a cylindrical, fast magnetohydrodynamic (MHD) shock wave in a neutrally ionized gas collapsing onto an axial line current that generates a power law in time, azimuthal magnetic field. The analysis is done

  2. Law Commissions – What is the essence of their law reform role?

    Directory of Open Access Journals (Sweden)

    Neil Faris

    2014-10-01

    Full Text Available Article by Neil Faris (Solicitor and a former Commissioner at the Northern Ireland Law Commission reflecting on the nature of law reform as carried out by law commissions. This is in the context of the author’s experience in the Northern Ireland Law Commission. The paper assesses the importance of independence in any law reform body and the particular impact which law commissioners may bring to the law reform process. The paper looks at the history of law reform in Northern Ireland leading to the establishment of the Commission with a brief overview of the work of the Commission. The conclusion is that there is a role for effective law reform driven by commissioner led independent law commissions. The author makes a strong case for the need for independent law commissions to promote high quality law reform. His article gives an idea about how law reform works in practice with law commissions providing one route for reforming the law.

  3. Floquet states of a kicked particle in a singular potential: Exponential and power-law profiles

    Science.gov (United States)

    Paul, Sanku; Santhanam, M. S.

    2018-03-01

    It is well known that, in the chaotic regime, all the Floquet states of kicked rotor system display an exponential profile resulting from dynamical localization. If the kicked rotor is placed in an additional stationary infinite potential well, its Floquet states display power-law profile. It has also been suggested in general that the Floquet states of periodically kicked systems with singularities in the potential would have power-law profile. In this work, we study the Floquet states of a kicked particle in finite potential barrier. By varying the height of finite potential barrier, the nature of transition in the Floquet state from exponential to power-law decay profile is studied. We map this system to a tight-binding model and show that the nature of decay profile depends on energy band spanned by the Floquet states (in unperturbed basis) relative to the potential height. This property can also be inferred from the statistics of Floquet eigenvalues and eigenvectors. This leads to an unusual scenario in which the level spacing distribution, as a window in to the spectral correlations, is not a unique characteristic for the entire system.

  4. Axial annular flow of power-law fluids - applicability of the limiting cases

    Czech Academy of Sciences Publication Activity Database

    Filip, Petr; David, Jiří

    2007-01-01

    Roč. 52, č. 4 (2007), s. 365-371 ISSN 0001-7043 R&D Projects: GA ČR GA103/06/1033 Institutional research plan: CEZ:AV0Z20600510 Keywords : Concentric annuli * Poiseuile flow * annular flow * power- law fluids * flow rate * pressure drop Subject RIV: BK - Fluid Dynamics

  5. Electrical efficiency and droop in MQW LEDs

    Science.gov (United States)

    Malyutenko, V. K.

    2014-02-01

    It is believed that low power conversion efficiency in commercial MQW LEDs occurs as a result of efficiency droop, current-induced dynamic degradation of the internal quantum efficiency, injection efficiency, and extraction efficiency. Broadly speaking, all these "quenching" mechanisms could be referred to as the optical losses. The vast advances of high-power InGaN and AlGaInP MQW LEDs have been achieved by addressing these losses. In contrast to these studies, in this paper we consider an alternative approach to make high-power LEDs more efficient. We identify current-induced electrical efficiency degradation (EED) as a strong limiting factor of power conversion efficiency. We found that EED is caused by current crowding followed by an increase in current-induced series resistance of a device. By decreasing the current spreading length, EED also causes the optical efficiency to degrade and stands for an important aspect of LED performance. This paper gives scientists the opportunity to look for different attributes of EED.

  6. The Forbes 400, the Pareto power-law and efficient markets

    Science.gov (United States)

    Klass, O. S.; Biham, O.; Levy, M.; Malcai, O.; Solomon, S.

    2007-01-01

    Statistical regularities at the top end of the wealth distribution in the United States are examined using the Forbes 400 lists of richest Americans, published between 1988 and 2003. It is found that the wealths are distributed according to a power-law (Pareto) distribution. This result is explained using a simple stochastic model of multiple investors that incorporates the efficient market hypothesis as well as the multiplicative nature of financial market fluctuations.

  7. Bridgeless SEPIC PFC Converter for Multistring LED Driver

    Science.gov (United States)

    Jha, Aman; Singh, Bhim

    2018-05-01

    This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.

  8. Analysis of diodes used as precision power detectors above the square law region

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1990-01-01

    The deviation from square law found in diode power detectors at moderate power levels has been modeled for a general system consisting of a number of diode detectors connected to a common arbitrary linear passive network, containing an approximately sinusoidal source. This situation covers the case...... if an extra-set of measurements is made in situ. For precision measurements the maximum power level can be increased by about 10 dB. The dynamic range can thus be increased sufficiently to enable fast measurements to be made with an accuracy of 10-3 dB...

  9. CFD modeling of a UV-LED photocatalytic odor abatement process in a continuous reactor

    International Nuclear Information System (INIS)

    Wang, Zimeng; Liu, Jing; Dai, Yuancan; Dong, Weiyang; Zhang, Shicheng; Chen, Jianmin

    2012-01-01

    Highlights: ► A CFD model is developed for a UV-LED based photocatalytic deodorization reactor. ► Radiation field model and Langmuir–Hinshelwood kinetics are integrated in the model. ► The model can predict the pollutant concentration profile and the reactor performance. ► LED distance is predicted to be a critical parameter in photocatalytic reactor design. - Abstract: This paper presents a model study of a UV light-emitting-diode (UV-LED) based photocatalytic odor abatement process. It integrated computational fluid dynamics (CFD) modeling of the gas flow in the reactor with LED-array radiation field calculation and Langmuir–Hinshelwood reaction kinetics. It was applied to simulate the photocatalytic degradation of dimethyl sulfide (DMS) in a UV-LED reactor based on experimentally determined chemical kinetic parameters. A non-linear power law relating reaction rate to irradiation intensity was adopted. The model could predict the steady state DMS concentration profiles by calculating the advection, diffusion and Langmuir–Hinshelwood reaction kinetics. By affecting the radiation intensity and uniformity, the position of the LED array relative to the catalyst appeared to be a critical parameter determining DMS removal efficiency. Too small distances might yield low quantum efficiency and consequently poor abatement performance. This study provided an example of LED-based photocatalytic process modeling and gave insights into the optimization of light source design for photocatalytic applications.

  10. Comment on "Time needed to board an airplane: a power law and the structure behind it".

    Science.gov (United States)

    Bernstein, Noam

    2012-08-01

    Frette and Hemmer [Phys. Rev. E 85, 011130 (2012)] recently showed that for a simple model for the boarding of an airplane, the mean time to board scales as a power law with the number of passengers N and the exponent is less than 1. They note that this scaling leads to the prediction that the "back-to-front" strategy, where passengers are divided into groups from contiguous ranges of rows and each group is allowed to board in turn from back to front once the previous group has found their seats, has a longer boarding time than would a single group. Here I extend their results to a larger number of passengers using a sampling approach and explore a scenario where the queue is presorted into groups from back to front, but allowed to enter the plane as soon as they can. I show that the power law dependence on passenger numbers is different for large N and that there is a boarding time reduction for presorted groups, with a power law dependence on the number of presorted groups.

  11. On the classical theory of ordinary linear differential equations of the second order and the Schroedinger equation for power law potentials

    International Nuclear Information System (INIS)

    Lima, M.L.; Mignaco, J.A.

    1983-01-01

    The power law potentials in the Schroedinger equation solved recently are shown to come from the classical treatment of the singularities of a linear, second order differential equation. This allows to enlarge the class of solvable power law potentials. (Author) [pt

  12. The enforcement order for the law for arrangement of surrounding areas of power generating facilities

    International Nuclear Information System (INIS)

    1979-01-01

    The order is defined under the law for arrangement of surrounding areas of power generating facilities. Establishers of power generating facilities shall be hereunder general electric enterprisers, wholesale electric enterprisers and the Power Reactor and Nuclear Fuel Development Corporation. The scale of power generating facilities provided by the order is 350,000 kilo-watts for atomic and steam power generation and 5,000 kilo-watts for hydroelectric power. Equipment closely related to atomic power generation shall include facilities for reprocessing and examination of nuclear fuel materials spent for power generating reactors, reactors used for research of the safety of power generating reactors, experimental fast breeding reactors and experimental uranium enrichment facilities. Requisites for the extent of industrial accumulation are that the area belongs to those self-governing bodies whose industrial accumulation is more than the 8th degree. Public facilities specified are those for communication, sports or recreation, environmental hygiene, education and culture, medicine, social welfare, fire fighting and heat supplying, etc. Governors of the prefectures shall file arrangement programs to the Minister in charge through the Minister of International Trade and Industry to get the permission stipulated by the law. Subsidies shall not be paid to those enterprises which are executed by the government or a part of the expenses is born or supported by it. (Okada, K.)

  13. Islamic Law

    Directory of Open Access Journals (Sweden)

    Doranda Maracineanu

    2009-06-01

    Full Text Available The law system of a State represents the body of rules passed or recognized by that State inorder to regulate the social relationships, rules that must be freely obeyed by their recipients, otherwisethe State intervening with its coercive power. Throughout the development of the society, pedants havebeen particularly interested in the issue of law systems, each supporting various classifications; theclassification that has remained is the one distinguishing between the Anglo-Saxon, the Roman-German,the religious and respectively the communist law systems. The third main international law system is theMuslim one, founded on the Muslim religion – the Islam. The Islam promotes the idea that Allah createdthe law and therefore it must be preserved and observed as such. Etymologically, the Arabian word“Islam” means “to be wanted, to obey” implying the fact that this law system promotes total andunconditioned submission to Allah. The Islamic law is not built on somebody of laws or leading cases,but has as source. The Islam is meant as a universal religion, the Koran promoting the idea of the unityof mankind; thus, one of the precepts in the Koran asserts that “all men are equal (…, there is nodifference between a white man and a black man, between one who is Arabian and one who is not,except for the measure in which they fear God.” The Koran is founded mainly on the Talmud, Hebrewsource of inspiration, and only on very few Christian sources. The Islam does not forward ideas whichcannot be materialized; on the contrary its ideas are purely practical, easy to be observed by the commonman, ideas subordinated to the principle of monotheism. The uncertainties and gaps of the Koran, whichhave been felt along the years, imposed the need for another set of rules, meant to supplement it – that isSunna. Sunna represents a body of laws and, consequently, the second source of the Koran. Sunnanarrates the life of the prophet Mohamed, the model to

  14. Laboratory constraints on chameleon dark energy and power-law fields

    OpenAIRE

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search---a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude betw...

  15. Laboratory Constraints on Chameleon Dark Energy and Power-Law Fields

    International Nuclear Information System (INIS)

    Steffen, J. H.; Baumbaugh, A.; Chou, A. S.; Mazur, P. O.; Tomlin, R.; Wester, W.; Upadhye, A.; Weltman, A.

    2010-01-01

    We report results from a search for chameleon particles created via photon-chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of unexplored chameleon power-law and dark energy models. These results exclude 5 orders of magnitude in the coupling of chameleons to photons covering a range of 4 orders of magnitude in chameleon effective mass and, for individual models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  16. The rule of law

    Directory of Open Access Journals (Sweden)

    Besnik Murati

    2015-07-01

    Full Text Available The state as an international entity and its impact on the individual’s right has been and still continues to be a crucial factor in the relationship between private and public persons. States vary in terms of their political system, however, democratic states are based on the separation of powers and human rights within the state. Rule of law is the product of many actors in a state, including laws, individuals, society, political system, separation of powers, human rights, the establishment of civil society, the relationship between law and the individual, as well as, individual-state relations. Purpose and focus of this study is the importance of a functioning state based on law, characteristics of the rule of law, separation of powers and the basic concepts of the rule of law.

  17. Flow of power-law fluids in fixed beds of cylinders or spheres

    KAUST Repository

    Singh, John P.; Padhy, Sourav; Shaqfeh, Eric S. G.; Koch, Donald L.

    2012-01-01

    is influenced by the Newtonian fluid stress and a body force representing the linear drag on the surrounding particles. We consider a similar analysis for a power-law fluid where the stress τ is related to the rate of strain e by τ = 2m en-1e, where m and n

  18. Possibilities of sanction of the improper behaviour of a power network operator. Instruments of energy economy act, public order law, and criminal law; Sanktionsmoeglichkeiten bei missbraeuchlichem Verhalten eines Energienetzbetreibers. Energiewirtschaftsrechtliche, ordnungsrechtliche und strafrechtliche Instrumentarien

    Energy Technology Data Exchange (ETDEWEB)

    Mitto, L.

    2007-07-01

    The liberalization of the electric power market and gas market has released a comprehensive reorganisation of the energy branch. Under this aspect, the author of the book under consideration reports on power network operators, their improper behaviour as well as the use of the instruments of energy economy act, public order law, and criminal law in order to sanction power network operators.

  19. Calculation of harmonic losses and ampacity in low-voltage power cables when used for feeding large LED lighting loads

    Directory of Open Access Journals (Sweden)

    N. J. Milardovich

    2014-10-01

    Full Text Available A numerical investigation on the harmonic disturbances in low-voltage cables feeding large LED loads is reported. A frequency domain analysis on several commercially-available LEDs was performed to investigate the signature of the harmonic current injected into the power system. Four-core cables and four single-core cable arrangements (three phases and neutral of small, medium, and large conductor cross sections, with the neutral conductor cross section approximately equal to the half of the phase conductors, were examined. The cables were modelled by using electromagnetic finite-element analysis software. High harmonic power losses (up to 2.5 times the value corresponding to an undistorted current of the same rms value of the first harmonic of the LED current were found. A generalized ampacity model was employed for re-rating the cables. It was found that the cross section of the neutral conductor plays an important role in the derating of the cable ampacity due to the presence of a high-level of triplen harmonics in the distorted current. The ampacity of the cables should be derated by about 40 %, almost independent of the conductor cross sections. The calculation have shown that an incoming widespread use of LED lamps in lighting could create significant additional harmonic losses in the supplying low-voltage lines, and thus more severely harmonic emission limits should be defined for LED lamps.

  20. Numerical simulation of nanofluids based on power-law fluids with flow and heat transfer

    Science.gov (United States)

    Li, Lin; Jiang, Yongyue; Chen, Aixin

    2017-04-01

    In this paper, we investigate the heat transfer of nanofluids based on power-law fluids and movement of nanoparticles with the effect of thermophoresis in a rotating circular groove. The velocity of circular groove rotating is a constant and the temperature on the wall is kept to be zero all the time which is different from the temperature of nanofluids in the initial time. The effects of thermophoresis and Brownian diffusion are considered in temperature and concentration equations, and it is assumed that the thermal conductivity of nanofluids is a function of concentration of nanoparticles. Based on numerical results, it can be found that nanofluids improve the process of heat transfer than base fluids in a rotating circular groove. The enhancement of heat transfer increases as the power law index of base fluids decreases.

  1. Experimental investigation on the spray characteristics of power-law fluid in a swirl injector

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Fuqiang; Chen, Shixing; Guo, Jinpeng; Jiao, Kui; Du, Qing [State Key Laboratory of Engines, Tianjin University, Tianjin, 300072 (China); Chang, Qing, E-mail: duqing@tju.edu.cn [Wuxi Fuel Injection Equipment Research Institute, China FAW CO., Wuxi, 214063 (China)

    2017-06-15

    High-speed photography and 3D phase Doppler methods are used to obtain the swirl jet images, 3D velocities and size distribution of different droplets (including deionized water and two kinds of power-law fluid). For the power-law fluids, a short circular jet is formed after the nozzle exit at low pressure. Along the X direction, the distributions of axial velocity w and Sauter mean diameter (SMD) are symmetrical and increase from the center to both sides. The effect of injection pressure on the radial velocity u is not obvious. Along the Z axis, the absolute value of 3D velocities decreases to some extent with droplets moving downstream. The SMD decreases apparently with the increment of the distance along the Z axis at 1.0 MPa. (paper)

  2. The enforcement order for the law for arrangement of surrounding areas of power generating facilities

    International Nuclear Information System (INIS)

    1977-01-01

    The Order is based on the prescriptions of the Law for the Arrangement of Surrounding Areas of Power Generating Facilities. Those establishing power generating facilities are general and wholesale electric enterprisers provided for by the Electricity Enterprises Act as well as the Power Reactor and Nuclear Fuel Development Corporation. The generating capacity is specified as 350,000 kilowatts for nuclear and steam power generating facilities, 150,000 kilowatts for those set up by the Corporation, 100,000 kilowatts for those using coal as main fuel, and 10,000 kilowatts for water power generation and geothermal plants. The facilities closely connected to nuclear power generation include the reprocessing facilities and test and examination facilities for nuclear fuel materials used for power-generating nuclear reactors, reactors used for the research on the safety of power generating reactors, and experimental reactors for fast breeder reactors. The public facilities consist of communication facilities, and the facilities for sports and recreations, environmental hygiene, education and culture, medicine, social welfare, fire fighting, etc. Prefectural governors ought to file the arrangement plans to the competent minister through the Minister of International Trade and Industry to get the permission prescribed by the Law. The subsidy is not granted to the expenses of the enterprises undertaken by the nation or those enterprises, a part of the expenses of which is borne or subsidized by the nation. (Okada, K.)

  3. Terrorism and information sharing between the intelligence and law enforcement communities in the US and the Netherlands: emergency criminal law?

    Directory of Open Access Journals (Sweden)

    John A. E. Vervaele

    2005-06-01

    Full Text Available Intelligence sharing between intelligence and police services with a view to preventing and combating terrorism is high on the political agenda in Brussels and The Hague. The Netherlands is one of the few countries in the EU where this topic is subject of political scrutiny. It also led to controversial case law. Recently, Justice Minister Donner has used an expedited procedure to submit a legislative proposal concerning shielded witnesses. This Bill raises many questions, that concern, amongst others, the discretion of intelligence services to determine which information will be provided for use in criminal proceedings and the relationship between this discretionary power and the connected legal duty of secrecy on the one hand and the rights of the defence to test and question that information on the other. Furthermore, questions raise regarding the evidentiary quality of this information. The proposed rules also influence the legitimacy of criminal law and the position of the criminal courts. What effect does the paradigm of security-orientated thinking have on the historical connection between criminal law and the rule of law? This issue is also addressed in this article.

  4. Critical review of the first-law efficiency in different power combined cycle architectures

    International Nuclear Information System (INIS)

    Iglesias Garcia, Steven; Ferreiro Garcia, Ramon; Carbia Carril, Jose; Iglesias Garcia, Denis

    2017-01-01

    Highlights: • The adiabatic expansion based TC can improve the energy efficiency of CCs. • A revolutionary TC can be a starting point to develop high-performance CCs. • A theoretical thermal efficiency of 83.7% was reached in a Nuclear Power Plant using a TC as bottoming cycle. - Abstract: This critical review explores the potential of an innovative trilateral thermodynamic cycle used to transform low-grade heat into mechanical work and compares its performance with relevant traditional thermodynamic cycles in combined cycles. The aim of this work is to show that combined cycles use traditional low efficiency power cycles in their bottoming cycle, and to evaluate theoretically the implementation of alternative power bottoming cycles. Different types of combined cycles have been reviewed, highlighting their relevant characteristics. The efficiencies of power plants using combined cycles are reviewed and compared. The relevance of researching thermodynamic cycles for combined cycle applications is that a vast amount of heat energy is available at negligible cost in the bottoming cycle of a combined cycle, with the drawback that existing thermal cycles cannot make efficient use of such available low temperature heat due to their low efficiency. The first-law efficiency is used as a parameter to compare and suggest improvements in the combined cycles (CCs) reviewed. The analysis shows that trilateral cycles using closed processes are by far the most efficient published thermal cycles for combined cycles to transform low-grade heat into mechanical work. An innovative trilateral bottoming cycle is proposed to show that the application of non-traditional power cycles can increase significantly the first-law efficiency of CCs. The highest first-law efficiencies achieved are: 85.55% in a CC using LNG cool, 73.82% for a transport vehicle CC, 74.40% in a marine CC, 83.07% in a CC for nuclear power plants, 73.82% in a CC using Brayton and Rankine cycles, 78.31% in a CC

  5. One loop back reaction on power law inflation

    International Nuclear Information System (INIS)

    Abramo, L.R.; Woodard, R.P.

    1999-01-01

    We consider quantum-mechanical corrections to a homogeneous, isotropic, and spatially flat geometry whose scale factor expands classically as a general power of the comoving time. The effects of both gravitons and the scalar inflaton are computed at one loop using the manifestly causal formalism of Schwinger [J. Math. Phys. 2, 407 (1961); Particles, Sources and Fields (Addison, Wesley, Reading, MA, 1970)] with the Feynman rules recently developed by Iliopoulos et al. [Nucl. Phys. B 534, 419 (1998)]. We find no significant effect, in marked contrast to the result obtained by Mukhanov and co-workers [Phys. Rev. Lett. 78, 1624 (1998); Phys. Rev. D 56, 3248 (1997)] for chaotic inflation based on a quadratic potential. By applying the canonical technique of Mukhanov and co-workers to the exponential potentials of power law inflation, we show that the two methods produce the same results, within the approximations employed, for these backgrounds. We therefore conclude that the shape of the inflaton potential can have an enormous impact on the one loop back reaction. copyright 1999 The American Physical Society

  6. High energy power-law tail in X-ray binaries and bulk Comptonization due to an outflow from a disk

    Science.gov (United States)

    Kumar, Nagendra

    2018-02-01

    We study the high energy power-law tail emission of X-ray binaries (XRBs) by a bulk Comptonization process which is usually observed in the very high soft (VHS) state of black hole (BH) XRBs and the high soft (HS) state of the neutron star (NS) and BH XRBs. Earlier, to generate the power-law tail in bulk Comptonization framework, a free-fall converging flow into BH or NS had been considered as a bulk region. In this work, for a bulk region we consider mainly an outflow geometry from the accretion disk which is bounded by a torus surrounding the compact object. We have two choices for an outflow geometry: (i) collimated flow and (ii) conical flow of opening angle θ _b and the axis is perpendicular to the disk. We also consider an azimuthal velocity of the torus fluids as a bulk motion where the fluids are rotating around the compact object (a torus flow). We find that the power-law tail can be generated in a torus flow having large optical depth and bulk speed (>0.75 c), and in conical flow with θ _b > ˜ 30° for a low value of Comptonizing medium temperature. Particularly, in conical flow the low opening angle is more favourable to generate the power-law tail in both the HS state and the VHS state. We notice that when the outflow is collimated, then the emergent spectrum does not have power-law component for a low Comptonizing medium temperature.

  7. Τhe observational and empirical thermospheric CO2 and NO power do not exhibit power-law behavior; an indication of their reliability

    Science.gov (United States)

    Varotsos, C. A.; Efstathiou, M. N.

    2018-03-01

    In this paper we investigate the evolution of the energy emitted by CO2 and NO from the Earth's thermosphere on a global scale using both observational and empirically derived data. In the beginning, we analyze the daily power observations of CO2 and NO received from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) equipment on the NASA Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite for the entire period 2002-2016. We then perform the same analysis on the empirical daily power emitted by CO2 and NO that were derived recently from the infrared energy budget of the thermosphere during 1947-2016. The tool used for the analysis of the observational and empirical datasets is the detrended fluctuation analysis, in order to investigate whether the power emitted by CO2 and by NO from the thermosphere exhibits power-law behavior. The results obtained from both observational and empirical data do not support the establishment of the power-law behavior. This conclusion reveals that the empirically derived data are characterized by the same intrinsic properties as those of the observational ones, thus enhancing the validity of their reliability.

  8. Adjustment to subtle time constraints and power law learning in rapid serial visual presentation

    Directory of Open Access Journals (Sweden)

    Jacqueline Chakyung Shin

    2015-11-01

    Full Text Available We investigated whether attention could be modulated through the implicit learning of temporal information in a rapid serial visual presentation (RSVP task. Participants identified two target letters among numeral distractors. The stimulus-onset asynchrony immediately following the first target (SOA1 varied at three levels (70, 98, and 126 ms randomly between trials or fixed within blocks of trials. Practice over three consecutive days resulted in a continuous improvement in the identification rate for both targets and attenuation of the attentional blink (AB, a decrement in target (T2 identification when presented 200-400 ms after another target (T1. Blocked SOA1s led to a faster rate of improvement in RSVP performance and more target order reversals relative to random SOA1s, suggesting that the implicit learning of SOA1 positively affected performance. The results also reveal power law learning curves for individual target identification as well as the reduction in the AB decrement. These learning curves reflect the spontaneous emergence of skill through subtle attentional modulations rather than general attentional distribution. Together, the results indicate that implicit temporal learning could improve high level and rapid cognitive processing and highlights the sensitivity and adaptability of the attentional system to subtle constraints in stimulus timing.

  9. Improved power quality based high brightness LED lamp driver

    African Journals Online (AJOL)

    user

    consists of a PFC Cuk DC-DC converter which operates in continuous conduction mode (CCM) to improve the ... In proposed LED driver as shown in Figure 1, a Cuk buck boost AC-DC converter ... Design and Analysis of Proposed LED Driver.

  10. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach.

    Science.gov (United States)

    Fan, Jiajie; Mohamed, Moumouni Guero; Qian, Cheng; Fan, Xuejun; Zhang, Guoqi; Pecht, Michael

    2017-07-18

    With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life.

  11. Reliability test and failure analysis of high power LED packages

    International Nuclear Information System (INIS)

    Chen Zhaohui; Zhang Qin; Wang Kai; Luo Xiaobing; Liu Sheng

    2011-01-01

    A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 0 C/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h, showing no visible degradation in optical performance for our modules, with two other vendors showing significant degradation. Some failure analysis methods such as C-SAM, Nano X-ray CT and optical microscope are used for LED packages. Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing. The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging. One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing. (semiconductor devices)

  12. A Single-Stage LED Tube Lamp Driver with Power-Factor Corrections and Soft Switching for Energy-Saving Indoor Lighting Applications

    Directory of Open Access Journals (Sweden)

    Chun-An Cheng

    2017-01-01

    Full Text Available This paper presents a single-stage alternating current (AC/direct current (DC light-emitting diode (LED tube lamp driver for energy-saving indoor lighting applications; this driver features power-factor corrections and soft switching, and also integrates a dual buck-boost converter with coupled inductors and a half-bridge series resonant converter cascaded with a bridge rectifier into a single-stage power-conversion topology. The features of the presented driver are high efficiency (>91%, satisfying power factor (PF > 0.96, low input-current total-harmonic distortion (THD < 10%, low output voltage ripple factor (<7.5%, low output current ripple factor (<8%, and zero-voltage switching (ZVS obtained on both power switches. Operational principles are described in detail, and experimental results obtained from an 18 W-rated LED tube lamp for T8/T10 fluorescent lamp replacements with input utility-line voltages ranging from 100 V to 120 V have demonstrated the functionality of the presented driver suitable for indoor lighting applications.

  13. Closing responsibilities: decommissioning and the law

    International Nuclear Information System (INIS)

    Macrory, R.

    1990-01-01

    Laws change over time, with the times. Interpretations of old laws shift and the need for new laws emerges. There are endless reasons for these necessary changes, but the basic impetus is the changing nature of societal circumstance. Fifty years ago there were no laws directly governing nuclear power in any way. Today we know that nuclear power touches people from their wallets to their descendants. Currently, many laws related to nuclear power are in place, laws which protect all sectors of society from electricity generating bodies to a newborn child, and the Chernobyl accident has broadened the legal ramifications of nuclear power even more. This expanding body of nuclear law reflects our expanding understanding of nuclear power from its technical beginnings to its societal consequences and implications. The law is now beginning to reflect the growing significance of decommissioning. What are the relationships between decommissioning and the existing laws, government agencies, and policies? Ironically, although the UK will lead the world in addressing decommissioning responsibilities, there are no explicit laws in place to govern the process. In the absence of specific legislation governing decommissioning, the primary responsibilities fall to the operators of the power plants, a circumstance not lost on those involved in privatization. In this chapter, the wide and varied legal ramifications of decommissioning are examined. (author)

  14. CALiPER Report 20.2: Dimming, Flicker, and Power Quality Characteristics of LED PAR38 Lamps

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-03-31

    This report focuses on the flicker and power quality performance of the Series 20 lamps at full output and various dimmed levels. All of the Series 20 PAR38 lamps that manufacturers claimed to be dimmable (including all halogen lamps) were evaluated individually (one lamp at a time) both on a switch and under the control of a phase-cut dimmer designed for use with "all classes of bulbs." Measurements of luminous flux, flicker, and power quality were taken at 10 target dimmed settings and compared with operation on a switch. Because only a single unit of each product was evaluated on a single dimmer that may or may not have been recommended by its manufacturer, this report focuses on the performance of the products relative to each other, rather than the best-case performance of each lamp or variation in performance delivered from each lamp. Despite these limitations, the results suggest that LED performance is improving, and performance trends are beginning to emerge, perhaps due in part to the identification of preferred LED driver strategies for lamp products.

  15. Numerical Modeling of the Flow of a Power Law Ceramic Slurry in the Tape Casting Process

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Hattel, Jesper Henri

    2012-01-01

    Multilayer ceramics and their application have increased recently. One of the most common ways used to produce these products is tape casting. In this process the wet tape thickness is one of the most determining parameters affecting the final properties of the product and it is therefore of great...... interest to be able to control it. In the present work the flow of La0.85Sr0.15MnO3 (LSM) material in the doctor blade region is modelled numerically with ANSYS Fluent in combination with an Ostwald power law constitutive equation. Based on rheometer experiments the constants in the Ostwald power law...

  16. Experimental study on the thermal management of high-power LED headlight cooling device integrated with thermoelectric cooler package

    International Nuclear Information System (INIS)

    Wang, Jing; Zhao, Xin-Jie; Cai, Yi-Xi; Zhang, Chun; Bao, Wei-Wei

    2015-01-01

    Highlights: • A novel TEC cooling system for multi-chip LED module was successfully developed. • Influences of liquid velocity on the system thermal performance were investigated. • TEC system is more sensitive to the input current than that of the mere air cooling. • The junction temperature can be maintained below 61.8 °C (liquid cooling & TEC). - Abstract: In view of the characteristics of high power light-emitting diodes (LEDs), such as strict junction temperature (T j ) control, the enhanced cooling models based on the thermoelectric cooler (TEC) were presented to meet the thermal demand of high-power LED headlight. The cooling performance of different devices (air cooling & TEC, liquid cooling & TEC) was evaluated and compared by measuring the LED case temperature. Details of the heat transfer performance, particularly, the start-up performances of the TEC cooler, as well as the influence of the fan rotate speed or liquid velocity on the system thermal performance were obtained. It was found that the thermal performance had been elevated dramatically due to the reduction of the hot side temperature, and the thermoelectric cooler was more sensitive to the external fan speed or liquid velocity than purely air cooling or liquid cooling. In addition, the optimal current for air cooling & TEC was 3A, and 5A for liquid cooling + TEC. Investigations of the simulated ambient temperature on junction temperature, forward voltage, and output light were conducted. Results indicated that the case temperature changed linear basically with the increase in heating power or the simulated ambient temperature. When the ambient temperature was within its severe level (60–65 °C), the junction temperature could be calculated to 59.5 °C, and the corresponding output light was 1607.3 lm

  17. Power law-based local search in spider monkey optimisation for lower order system modelling

    Science.gov (United States)

    Sharma, Ajay; Sharma, Harish; Bhargava, Annapurna; Sharma, Nirmala

    2017-01-01

    The nature-inspired algorithms (NIAs) have shown efficiency to solve many complex real-world optimisation problems. The efficiency of NIAs is measured by their ability to find adequate results within a reasonable amount of time, rather than an ability to guarantee the optimal solution. This paper presents a solution for lower order system modelling using spider monkey optimisation (SMO) algorithm to obtain a better approximation for lower order systems and reflects almost original higher order system's characteristics. Further, a local search strategy, namely, power law-based local search is incorporated with SMO. The proposed strategy is named as power law-based local search in SMO (PLSMO). The efficiency, accuracy and reliability of the proposed algorithm is tested over 20 well-known benchmark functions. Then, the PLSMO algorithm is applied to solve the lower order system modelling problem.

  18. Functional Analysis in Long-Term Operation of High Power UV-LEDs in Continuous Fluoro-Sensing Systems for Hydrocarbon Pollution

    Science.gov (United States)

    Arques-Orobon, Francisco Jose; Nuñez, Neftali; Vazquez, Manuel; Gonzalez-Posadas, Vicente

    2016-01-01

    This work analyzes the long-term functionality of HP (High-power) UV-LEDs (Ultraviolet Light Emitting Diodes) as the exciting light source in non-contact, continuous 24/7 real-time fluoro-sensing pollutant identification in inland water. Fluorescence is an effective alternative in the detection and identification of hydrocarbons. The HP UV-LEDs are more advantageous than classical light sources (xenon and mercury lamps) and helps in the development of a low cost, non-contact, and compact system for continuous real-time fieldwork. This work analyzes the wavelength, output optical power, and the effects of viscosity, temperature of the water pollutants, and the functional consistency for long-term HP UV-LED working operation. To accomplish the latter, an analysis of the influence of two types 365 nm HP UV-LEDs degradation under two continuous real-system working mode conditions was done, by temperature Accelerated Life Tests (ALTs). These tests estimate the mean life under continuous working conditions of 6200 h and for cycled working conditions (30 s ON & 30 s OFF) of 66,000 h, over 7 years of 24/7 operating life of hydrocarbon pollution monitoring. In addition, the durability in the face of the internal and external parameter system variations is evaluated. PMID:26927113

  19. Equilibrium measures and Cramer asymptotics in a non-invertible dynamical system with power-law mixing

    International Nuclear Information System (INIS)

    Sarazhinskii, D S

    2004-01-01

    We consider a dynamical system generated by a shift in the space of finite-valued one-sided sequences. We study spectral properties of Perron-Frobenius operators associated with this system, whose potentials on the number of the term of the sequence have power-law dependence. Using these operators, we construct a family of equilibrium probability measures in the phase space having the property of power-law mixing. For these measures we prove a central limit theorem for functions in phase space and a Cramer-type theorem for the probabilities of large deviations. Similar results for the significantly simpler case of exponential decay in the dependence of the potentials on the number of the term of the sequence were previously obtained by the author.

  20. CALiPER Retail Lamps Study 3.1: Dimming, Flicker, and Power Quality Characteristics of LED A Lamps

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-12-31

    This CALiPER report examines the characteristics of a subset of lamps from CALiPER Retail Lamps Study 3 in more detail. Specifically, it focuses on the dimming, power quality, and flicker characteristics of 14 LED A lamps, as controlled by four different retail-available dimmers.

  1. Mining law and energy law in the context of today's most urgent problems

    International Nuclear Information System (INIS)

    Hueffer, U.; Ipsen, K.; Tettinger, P.J.

    1989-01-01

    Present mining law and energy law is discussed in 29 papers. Fundamental aspects of legal policy are discussed from the view of the Federal Government and of the Land of Nordrhein-Westfalen. Among the subjects discussed are: Property rights and mining; brown coal projecting; instruments for the promotion of power generation from coal; law on mining damage, industrial safety, and social security. There are several papers on legal problems of power supply, e.g. the autonomy of public utilities, the construction of power supply networks, the utilisation of renewable energy sources, waste incineration, and court decisions in the nuclear licensing procedure. There is a section on international law and a comparison of legal regulations, comprising: legal measures and standards within the IAEA; organisation and tasks of the IEA, energy law and energy policy of the USA, Japan, Great Britain, France, and the COMECON states (the latter referred to the production of energy sources and the electric power generation capacity). (orig./HP) [de

  2. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach

    Directory of Open Access Journals (Sweden)

    Jiajie Fan

    2017-07-01

    Full Text Available With the expanding application of light-emitting diodes (LEDs, the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD, defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED’s optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1 the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2 the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs, and color rendering indexes (CRIs of phosphor-converted (pc-white LEDs, and also can estimate the residual color life.

  3. Disobeying Power Laws: Perils for Theory and Method

    Directory of Open Access Journals (Sweden)

    G. Christopher Crawford

    2012-08-01

    Full Text Available The “norm of normality” is a myth that organization design scholars should believe only at their peril. In contrast to the normal (bell-shaped distribution with independent observations and linear relationships assumed by Gaussian statistics, research shows that nearly every input and outcome in organizational domains is power-law (Pareto distributed. These highly skewed distributions exhibit unstable means, unlimited variance, underlying interdependence, and extreme outcomes that disproportionally influence the entire system, making Gaussian methods and assumptions largely invalid. By developing more focused research designs and using methods that assume interdependence and potentially nonlinear relationships, organization design scholars can develop theories that more closely depict empirical reality and provide more useful insights to practitioners and other stakeholders.

  4. Backreaction of Cosmological Fluctuations during Power-Law Inflation

    International Nuclear Information System (INIS)

    Marozzi, G.

    2007-01-01

    We study the renormalized energy-momentum tensor of cosmological scalar fluctuations during the slow-rollover regime for power-law inflation and find that it is characterized by a negative energy density at the leading order, with the same time behavior as the background energy. The average expansion rate appears decreased by the backreaction of the effective energy of cosmological fluctuations, but this value is comparable with the energy of the background only if inflation starts at a Planckian energy. We also find that, for this particular model, the first- and second-order inflaton fluctuations are decoupled and satisfy the same equation of motion. To conclude, the fourth-order adiabatic expansion for the inflaton scalar field is evaluated for a general potential V(φ)

  5. Universal Expression of Efficiency at Maximum Power: A Quantum-Mechanical Brayton Engine Working with a Single Particle Confined in a Power-Law Trap

    International Nuclear Information System (INIS)

    Ye Zhuo-Lin; Li Wei-Sheng; Lai Yi-Ming; He Ji-Zhou; Wang Jian-Hui

    2015-01-01

    We propose a quantum-mechanical Brayton engine model that works between two superposed states, employing a single particle confined in an arbitrary power-law trap as the working substance. Applying the superposition principle, we obtain the explicit expressions of the power and efficiency, and find that the efficiency at maximum power is bounded from above by the function: η_+ = θ/(θ + 1), with θ being a potential-dependent exponent. (paper)

  6. Novel algorithm and MATLAB-based program for automated power law analysis of single particle, time-dependent mean-square displacement

    Science.gov (United States)

    Umansky, Moti; Weihs, Daphne

    2012-08-01

    In many physical and biophysical studies, single-particle tracking is utilized to reveal interactions, diffusion coefficients, active modes of driving motion, dynamic local structure, micromechanics, and microrheology. The basic analysis applied to those data is to determine the time-dependent mean-square displacement (MSD) of particle trajectories and perform time- and ensemble-averaging of similar motions. The motion of particles typically exhibits time-dependent power-law scaling, and only trajectories with qualitatively and quantitatively comparable MSD should be ensembled. Ensemble averaging trajectories that arise from different mechanisms, e.g., actively driven and diffusive, is incorrect and can result inaccurate correlations between structure, mechanics, and activity. We have developed an algorithm to automatically and accurately determine power-law scaling of experimentally measured single-particle MSD. Trajectories can then categorized and grouped according to user defined cutoffs of time, amplitudes, scaling exponent values, or combinations. Power-law fits are then provided for each trajectory alongside categorized groups of trajectories, histograms of power laws, and the ensemble-averaged MSD of each group. The codes are designed to be easily incorporated into existing user codes. We expect that this algorithm and program will be invaluable to anyone performing single-particle tracking, be it in physical or biophysical systems. Catalogue identifier: AEMD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMD_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 25 892 No. of bytes in distributed program, including test data, etc.: 5 572 780 Distribution format: tar.gz Programming language: MATLAB (MathWorks Inc.) version 7.11 (2010b) or higher, program

  7. Extended power-law scaling of air permeabilities measured on a block of tuff

    Directory of Open Access Journals (Sweden)

    M. Siena

    2012-01-01

    Full Text Available We use three methods to identify power-law scaling of multi-scale log air permeability data collected by Tidwell and Wilson on the faces of a laboratory-scale block of Topopah Spring tuff: method of moments (M, Extended Self-Similarity (ESS and a generalized version thereof (G-ESS. All three methods focus on q-th-order sample structure functions of absolute increments. Most such functions exhibit power-law scaling at best over a limited midrange of experimental separation scales, or lags, which are sometimes difficult to identify unambiguously by means of M. ESS and G-ESS extend this range in a way that renders power-law scaling easier to characterize. Our analysis confirms the superiority of ESS and G-ESS over M in identifying the scaling exponents, ξ(q, of corresponding structure functions of orders q, suggesting further that ESS is more reliable than G-ESS. The exponents vary in a nonlinear fashion with q as is typical of real or apparent multifractals. Our estimates of the Hurst scaling coefficient increase with support scale, implying a reduction in roughness (anti-persistence of the log permeability field with measurement volume. The finding by Tidwell and Wilson that log permeabilities associated with all tip sizes can be characterized by stationary variogram models, coupled with our findings that log permeability increments associated with the smallest tip size are approximately Gaussian and those associated with all tip sizes scale show nonlinear variations in ξ(q with q, are consistent with a view of these data as a sample from a truncated version (tfBm of self-affine fractional Brownian motion (fBm. Since in theory the scaling exponents, ξ(q, of tfBm vary linearly with q we conclude that nonlinear scaling in our case is not an indication of multifractality but an artifact of sampling from tfBm. This allows us to explain theoretically how power-law scaling of our data, as well

  8. Determination of LEDs degradation with entropy generation rate

    Science.gov (United States)

    Cuadras, Angel; Yao, Jiaqiang; Quilez, Marcos

    2017-10-01

    We propose a method to assess the degradation and aging of light emitting diodes (LEDs) based on irreversible entropy generation rate. We degraded several LEDs and monitored their entropy generation rate ( S ˙ ) in accelerated tests. We compared the thermoelectrical results with the optical light emission evolution during degradation. We find a good relationship between aging and S ˙ (t), because S ˙ is both related to device parameters and optical performance. We propose a threshold of S ˙ (t) as a reliable damage indicator of LED end-of-life that can avoid the need to perform optical measurements to assess optical aging. The method lays beyond the typical statistical laws for lifetime prediction provided by manufacturers. We tested different LED colors and electrical stresses to validate the electrical LED model and we analyzed the degradation mechanisms of the devices.

  9. Effect of the length of inflation on angular TT and TE power spectra in power-law inflation

    International Nuclear Information System (INIS)

    Hirai, Shiro; Takami, Tomoyuki

    2006-01-01

    The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(η) = (-η) p = t q . Considering various pre-inflation models with radiation-dominated or scalar matter-dominated periods before inflation in combination with two matching conditions, the temperature angular power spectrum (TT) and temperature-polarization cross-power spectrum (TE) are calculated and a likelihood analysis is performed. It is shown that the discrepancies between the Wilkinson microwave anisotropy probe (WMAP) data and the ΛCDM model, such as suppression of the spectrum at l = 2, 3 and oscillatory behaviour, may be explained by the finite length of inflation model if the length of inflation is near 60 e-folds and q ≥ 300. The proposed models retain similar values of χ 2 to that achieved by the ΛCDM model with respect to fit to the WMAP data, but display different characteristics of the angular TE power spectra at l ≤ 20

  10. Power-law correlations and finite-size effects in silica particle aggregates studied by small-angle neutron scattering

    DEFF Research Database (Denmark)

    Freltoft, T.; Kjems, Jørgen; Sinha, S. K.

    1986-01-01

    Small-angle neutron scattering from normal, compressed, and water-suspended powders of aggregates of fine silica particles has been studied. The samples possessed average densities ranging from 0.008 to 0.45 g/cm3. Assuming power-law correlations between particles and a finite correlation length ξ......, the authors derive the scattering function S(q) from specific models for particle-particle correlation in these systems. S(q) was found to provide a satisfactory fit to the data for all samples studied. The fractal dimension df corresponding to the power-law correlation was 2.61±0.1 for all dry samples, and 2...

  11. Free convection heat and mass transfer in a power law fluid past an inclined surface with thermophoresis

    Directory of Open Access Journals (Sweden)

    Medhat M. Helal

    2013-10-01

    Full Text Available The problem of heat and mass transfer in a power law, two-dimensional, laminar, boundary layer flow of a viscous incompressible fluid over an inclined plate with heat generation and thermophoresis is investigated by the characteristic function method. The governing non-linear partial differential equations describing the flow and heat transfer problem are transformed into a set of coupled non-linear ordinary differential equation which was solved using Runge–Kutta shooting method. Exact solutions for the dimensionless temperature and concentration profiles, are presented graphically for different physical parameters and for the different power law exponents 0  0.5.

  12. China's renewables law

    International Nuclear Information System (INIS)

    Zhu Li

    2005-01-01

    The paper discusses China's Renewable Energy Promotion Law which will come into force in January 2006. The law shows China's commitment to renewable energy sources. The target is to raise the country's energy consumption from renewables to 10% by 2020. Data for current capacity, and expected capacity by 2020, are given for wind power, solar power, biomass and hydroelectric power. The financial and technological hurdles which China must overcome are mentioned briefly

  13. Laboratory constraints on chameleon dark energy and power-law fields

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Upadhye, Amol; Baumbaugh, Al; Chou, Aaron S.; Mazur, Peter O.; Tomlin, Ray; Weltman, Amanda; Wester, William

    2010-01-01

    We report results from the GammeV Chameleon Afterglow Search - a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models and dark energy models not previously explored. These results exclude five orders of magnitude in the coupling of chameleons to photons covering a range of four orders of magnitude in chameleon effective mass and, for individual chameleon models, exclude between 4 and 12 orders of magnitude in chameleon couplings to matter.

  14. Jell-O Optics: Edibly Exploring Snell's Law and Optical Power

    Science.gov (United States)

    Hendryx, Jennifer; Reynolds, Mathias

    2012-03-01

    This presentation details a laboratory exercise and/or demonstration of refraction with an inexpensive, simple set-up: a pan of Jell-O, protractors, and laser pointers. This activity is presented from the perspective of an optical sciences graduate student who has spent the school year team-teaching high school math and physics (through Academic Decathlon). The goal is to present some of the fundamentals of optics with an enjoyable and affordable approach. The concepts include Snell's law, index of refraction, and optical power/focal length as they relate to the curvature of a lens.

  15. Measurement of the photometric characteristics of LEDs

    International Nuclear Information System (INIS)

    Nazarenko, L.A.; Zubkov, D.P.

    2015-01-01

    Proposed and implemented a method for measuring LEDs, which is based on self-calibration of the LED goniophotometer facility by using a trap-detector. Designed and manufactured automated goniophotometer, which provides a measurement of high power LEDs at a specified junction temperature. Designed and experimentally researched the photometer with a photometric sphere based diffuser, which meets all requirements of CIE for photometric measurements of LEDs

  16. Birth and death of protein domains: A simple model of evolution explains power law behavior

    Directory of Open Access Journals (Sweden)

    Berezovskaya Faina S

    2002-10-01

    Full Text Available Abstract Background Power distributions appear in numerous biological, physical and other contexts, which appear to be fundamentally different. In biology, power laws have been claimed to describe the distributions of the connections of enzymes and metabolites in metabolic networks, the number of interactions partners of a given protein, the number of members in paralogous families, and other quantities. In network analysis, power laws imply evolution of the network with preferential attachment, i.e. a greater likelihood of nodes being added to pre-existing hubs. Exploration of different types of evolutionary models in an attempt to determine which of them lead to power law distributions has the potential of revealing non-trivial aspects of genome evolution. Results A simple model of evolution of the domain composition of proteomes was developed, with the following elementary processes: i domain birth (duplication with divergence, ii death (inactivation and/or deletion, and iii innovation (emergence from non-coding or non-globular sequences or acquisition via horizontal gene transfer. This formalism can be described as a birth, death and innovation model (BDIM. The formulas for equilibrium frequencies of domain families of different size and the total number of families at equilibrium are derived for a general BDIM. All asymptotics of equilibrium frequencies of domain families possible for the given type of models are found and their appearance depending on model parameters is investigated. It is proved that the power law asymptotics appears if, and only if, the model is balanced, i.e. domain duplication and deletion rates are asymptotically equal up to the second order. It is further proved that any power asymptotic with the degree not equal to -1 can appear only if the hypothesis of independence of the duplication/deletion rates on the size of a domain family is rejected. Specific cases of BDIMs, namely simple, linear, polynomial and rational

  17. Characterization of fish sauce aroma-impact compounds using GC-MS, SPME-Osme-GCO, and Stevens' power law exponents.

    Science.gov (United States)

    Pham, A J; Schilling, M W; Yoon, Y; Kamadia, V V; Marshall, D L

    2008-05-01

    The objectives of this study were to characterize volatile compounds and to determine the characteristic aromas associated with impact compounds in 4 fish sauces using solid-phase micro-extraction, gas chromatography-mass spectrometry, Osme, and gas chromatography olfactometry (SPME-Osme-GCO) coupled with Stevens' Power Law. Compounds were separated using GCMS and GCO and were identified with the mass spectral database, aroma perceived at the sniffing port, retention indices, and verification of compounds by authentic standards in the GCMS and GCO. Aromas that were isolated and present in all 4 fish sauce samples at all concentrations included fishy (trimethylamine), pungent and dirty socks (combination of butanoic, pentanoic, hexanoic, and heptanoic acids), cooked rice and buttery popcorn (2,6-dimethyl pyrazine), and sweet and cotton candy (benzaldehyde). All fish sauces contained the same aromas as determined by GCO and GCMS (verified using authentic standard compounds), but the odor intensity associated with each compound or group of compounds was variable for different fish sauce samples. Stevens' Power Law exponents were also determined using this analytical technique, but exponents were not consistent for the same compounds that were found in all fish sauces. Stevens' Power Law exponents ranged from 0.14 to 0.37, 0.24 to 0.34, 0.09 to 0.21, and 0.10 to 0.35 for dirty socks, fishy, buttery popcorn, and sweet aromas, respectively. This demonstrates that there is variability in Stevens' Power Law exponents for odorants within fish sauce samples.

  18. Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

    Science.gov (United States)

    Walicka, A.

    2018-02-01

    In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

  19. Flows of Newtonian and Power-Law Fluids in Symmetrically Corrugated Cappilary Fissures and Tubes

    Directory of Open Access Journals (Sweden)

    Walicka A.

    2018-02-01

    Full Text Available In this paper, an analytical method for deriving the relationships between the pressure drop and the volumetric flow rate in laminar flow regimes of Newtonian and power-law fluids through symmetrically corrugated capillary fissures and tubes is presented. This method, which is general with regard to fluid and capillary shape, can also be used as a foundation for different fluids, fissures and tubes. It can also be a good base for numerical integration when analytical expressions are hard to obtain due to mathematical complexities. Five converging-diverging or diverging-converging geometrics, viz. wedge and cone, parabolic, hyperbolic, hyperbolic cosine and cosine curve, are used as examples to illustrate the application of this method. For the wedge and cone geometry the present results for the power-law fluid were compared with the results obtained by another method; this comparison indicates a good compatibility between both the results.

  20. The California Law Enforcement Community’s Intelligence-Led Policing Capacity

    Science.gov (United States)

    2010-12-01

    intelligence product used for sound decision making , strategic targeting, and more efficient resource allocation, whereas lack of clarity and the...providing law enforcement executives with actionable intelligence products for sound decision making , strategic targeting, and efficient resource

  1. Generation of solar spectrum by using LEDs

    Science.gov (United States)

    Lu, Pengzhi; Yang, Hua; Pei, Yanrong; Li, Jing; Xue, Bin; Wang, Junxi; Li, Jinmin

    2016-09-01

    Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering index and special spectral characteristics has received more and more attention. This paper is intended to report a solar spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source, which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681, 5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the multichip LED light source is a competitive candidate for applications where special spectral is required, such as colorimetric measurements, visual inspection, gemstone identification and agriculture.

  2. POWER-LAW TEMPLATE FOR INFRARED POINT-SOURCE CLUSTERING

    Energy Technology Data Exchange (ETDEWEB)

    Addison, Graeme E.; Dunkley, Joanna [Sub-department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Hajian, Amir; Das, Sudeep; Hincks, Adam D.; Page, Lyman A.; Staggs, Suzanne T. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Viero, Marco [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Devlin, Mark J.; Reese, Erik D. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Halpern, Mark; Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Hlozek, Renee; Marriage, Tobias A.; Spergel, David N. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban 4041 (South Africa); Wollack, Edward [NASA/Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

    2012-06-20

    We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 {approx}< l {approx}< 2200), the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST; 250, 350, and 500 {mu}m; 1000 {approx}< l {approx}< 9000), and from correlating BLAST and Atacama Cosmology Telescope (ACT; 148 and 218 GHz) maps. We find that the clustered power over the range of angular scales and frequencies considered is well fitted by a simple power law of the form C{sup clust}{sub l}{proportional_to}l{sup -n} with n = 1.25 {+-} 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, {nu}{sup {beta}} B({nu}, T{sub eff}), with a single emissivity index {beta} = 2.20 {+-} 0.07 and effective temperature T{sub eff} = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be {alpha}{sub 150-220} = 3.68 {+-} 0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model.

  3. Power-law approach to modeling biological systems. II. Application to ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Voit, E O; Savageau, M A

    1982-01-01

    The use of the power-law formalism is illustrated by modeling yeast ethanol production in batch culture at high cell densities. Parameter values are estimated from experimental data. The results suggest that ethanol killing of viable cells and lysis of nonviable cells are major determinants of system behavior, whereas catabolism of ethanol and inhibition of cell growth by ethanol appear to be insignificant under these experimental conditions.

  4. Fine-hyperfine splittings of quarkonium levels in an effective power-law potential

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N; Jena, S N [Utkal Univ., Bhubaneswar (India). Dept. of Physics

    1980-12-01

    We have shown that an effective non-coulombic power-law potential generating spin dependence through scalar and vector exchanges in almost equal proportions along with a very small or zero quark anomalous moment can describe very satisfactorily the up-to-date data on the fine-hyperfine levels and the leptonic width ratios of the vector mesons in the cc and bb families in a flavour independent manner.

  5. LED; Zum Thema LED

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This collection of articles on the subject of light emitting diodes (LED) provides technical information on LED technology, examines latest developments and provides examples of LED use in practice. An 'ABC' of LED technology is presented and fifteen common LED mistakes are noted. The chances and risks of LED use are discussed as is the retrofitting of lighting installations with LEDs. The use of LEDs in street lighting is examined. The journal also includes interviews with architects and a lighting designer. Practical examples of the use of LEDs include the refurbished parliamentary library in Berne, their use in the bird sanctuary headquarters in Sempach, Switzerland, as well as LED use in sales outlets. Also, the use of LED lighting in a spa gazebo in Lucerne is examined.

  6. Internationalization of law globalization, international law and complexity

    CERN Document Server

    Dias Varella, Marcelo

    2014-01-01

    The book provides an overview of how international law is today constructed through diverse macro and microprocesses that expand its traditional subjects and sources, with the attribution of sovereign capacity and power to the international plane (moving the international toward the national). Simultaneously, national laws approximate laws of other nations (moving among nations or moving the national toward the international) and new sources of legal norms emerge, independent of states and international organisations. This expansion occurs in many subject areas, with specific structures: commercial, environmental, human rights, humanitarian, financial, criminal and labor law contribute to the formation of post national law with different modes of functioning, different actors and different sources of law that should be understood as a new complexity of law.

  7. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  8. Viscous-elastic dynamics of power-law fluids within an elastic cylinder

    Science.gov (United States)

    Boyko, Evgeniy; Bercovici, Moran; Gat, Amir D.

    2017-07-01

    In a wide range of applications, microfluidic channels are implemented in soft substrates. In such configurations, where fluidic inertia and compressibility are negligible, the propagation of fluids in channels is governed by a balance between fluid viscosity and elasticity of the surrounding solid. The viscous-elastic interactions between elastic substrates and non-Newtonian fluids are particularly of interest due to the dependence of viscosity on the state of the system. In this work, we study the fluid-structure interaction dynamics between an incompressible non-Newtonian fluid and a slender linearly elastic cylinder under the creeping flow regime. Considering power-law fluids and applying the thin shell approximation for the elastic cylinder, we obtain a nonhomogeneous p-Laplacian equation governing the viscous-elastic dynamics. We present exact solutions for the pressure and deformation fields for various initial and boundary conditions for both shear-thinning and shear-thickening fluids. We show that in contrast to Stokes' problem where a compactly supported front is obtained for shear-thickening fluids, here the role of viscosity is inversed and such fronts are obtained for shear-thinning fluids. Furthermore, we demonstrate that for the case of a step in inlet pressure, the propagation rate of the front has a tn/n +1 dependence on time (t ), suggesting the ability to indirectly measure the power-law index (n ) of shear-thinning liquids through measurements of elastic deformation.

  9. Advances in LEDs for automotive applications

    Science.gov (United States)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  10. DOES A SCALING LAW EXIST BETWEEN SOLAR ENERGETIC PARTICLE EVENTS AND SOLAR FLARES?

    International Nuclear Information System (INIS)

    Kahler, S. W.

    2013-01-01

    Among many other natural processes, the size distributions of solar X-ray flares and solar energetic particle (SEP) events are scale-invariant power laws. The measured distributions of SEP events prove to be distinctly flatter, i.e., have smaller power-law slopes, than those of the flares. This has led to speculation that the two distributions are related through a scaling law, first suggested by Hudson, which implies a direct nonlinear physical connection between the processes producing the flares and those producing the SEP events. We present four arguments against this interpretation. First, a true scaling must relate SEP events to all flare X-ray events, and not to a small subset of the X-ray event population. We also show that the assumed scaling law is not mathematically valid and that although the flare X-ray and SEP event data are correlated, they are highly scattered and not necessarily related through an assumed scaling of the two phenomena. An interpretation of SEP events within the context of a recent model of fractal-diffusive self-organized criticality by Aschwanden provides a physical basis for why the SEP distributions should be flatter than those of solar flares. These arguments provide evidence against a close physical connection of flares with SEP production.

  11. Head-mounted LED for optogenetic experiments of freely-behaving animal

    Science.gov (United States)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  12. Light Fragment Production and Power Law Behavior in Au + Au Collisions

    International Nuclear Information System (INIS)

    Wang, S.; Albergo, S.; Bieser, F.; Brady, F.P.; Caccia, Z.; Cebra, D.A.; Chacon, A.D.; Chance, J.L.; Choi, Y.; Costa, S.; Elliott, J.B.; Gilkes, M.L.; Hauger, J.A.; Hirsch, A.S.; Hjort, E.L.; Insolia, A.; Justice, M.; Keane, D.; Kintner, J.; Lisa, M.A.; Matis, H.S.; McMahan, M.; McParland, C.; Olson, D.L.; Partlan, M.D.; Porile, N.T.; Potenza, R.; Rai, G.; Rasmussen, J.; Ritter, H.G.; Romanski, J.; Romero, J.L.; Russo, G.V.; Scharenberg, R.P.; Scott, A.; Shao, Y.; Srivastava, B.K.; Symons, T.J.M.; Tincknell, M.L.; Tuve, C.; Warren, P.G.; Weerasundara, D.; Wieman, H.H.; Wolf, K.L.

    1995-01-01

    Using charged-particle-exclusive measurements of Au+Au collisions in the LBL Bevalac's EOS time projection chamber, we investigate momentum-space densities of fragments up to 4 He as a function of fragment transverse momentum, azimuth relative to the reaction plane, rapidity, multiplicity, and beam energy. Most features of these densities above a transverse momentum threshold are consistent with momentum-space coalescence, and, in particular, the increase in sideward flow with fragment mass is generally well described by a momentum-space power law

  13. Formation of hard power laws in the energetic particle spectra resulting from relativistic magnetic reconnection.

    Science.gov (United States)

    Guo, Fan; Li, Hui; Daughton, William; Liu, Yi-Hsin

    2014-10-10

    Using fully kinetic simulations, we demonstrate that magnetic reconnection in relativistic plasmas is highly efficient at accelerating particles through a first-order Fermi process resulting from the curvature drift of particles in the direction of the electric field induced by the relativistic flows. This mechanism gives rise to the formation of hard power-law spectra in parameter regimes where the energy density in the reconnecting field exceeds the rest mass energy density σ ≡ B(2)/(4πnm(e)c(2))>1 and when the system size is sufficiently large. In the limit σ ≫ 1, the spectral index approaches p = 1 and most of the available energy is converted into nonthermal particles. A simple analytic model is proposed which explains these key features and predicts a general condition under which hard power-law spectra will be generated from magnetic reconnection.

  14. LED's in Physics Demos: A Handful of Examples.

    Science.gov (United States)

    Lottis, Dan; Jaeger, Herbert

    1996-01-01

    Describes the use of light-emitting diodes (LED) instead of incandescent bulbs in experiments that generally use battery and bulbs to enable students to explore and understand fundamental electrical phenomena. Presents the following examples: Faraday's Law demonstration, conductors and insulators, and rectifying action of a diode. (JRH)

  15. Fine-hyperfine splittings of quarkonium levels in an effective power-law potential

    International Nuclear Information System (INIS)

    Barik, N.; Jena, S.N.

    1980-01-01

    We have shown that an effective non-coulombic power-law potential generating spin dependence through scalar and vector exchanges in almost equal proportions along with a very small or zero quark anomalous moment can describe very satisfactorily the up-to-date data on the fine-hyperfine levels and the leptonic width ratios of the vector mesons in the cc and bb families in a flavour independent manner. (orig.)

  16. Quantum healing of classical singularities in power-law spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Helliwell, T M [Department of Physics, Harvey Mudd College, Claremont, CA 91711 (United States); Konkowski, D A [Department of Mathematics, US Naval Academy, Annapolis, MD 21402 (United States)

    2007-07-07

    We study a broad class of spacetimes whose metric coefficients reduce to powers of a radius r in the limit of small r. Among these four-parameter 'power-law' metrics, we identify those parameters for which the spacetimes have classical singularities as r {yields} 0. We show that a large set of such classically-singular spacetimes is nevertheless non-singular quantum mechanically, in that the Hamiltonian operator is essentially self-adjoint, so that the evolution of quantum wave packets lacks the ambiguity associated with scattering off singularities. Using these metrics, the broadest class yet studied to compare classical with quantum singularities, we explore the physical reasons why some that are singular classically are 'healed' quantum mechanically, while others are not. We show that most (but not all) of the remaining quantum-mechanically singular spacetimes can be excluded if either the weak energy condition or the dominant energy condition is invoked, and we briefly discuss the effect of this work on the strong cosmic censorship conjecture.

  17. Do we have an acceptable model of power-law creep?

    CSIR Research Space (South Africa)

    Nabarro, FRN

    2004-12-15

    Full Text Available 387–389 (2004) 659–664 Do we have an acceptable model of power-law creep? F.R.N. Nabarro a,b,∗ a Condensed Matter Physics Research Group, School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa b... an exponential function 0921-5093/$ – see front matter © 2004 Published by Elsevier B.V. doi:10.1016/j.msea.2003.09.118 660 F.R.N. Nabarro / Materials Science and Engineering A 387–389 (2004) 659–664 of the stress. There is little evidence whether the physical...

  18. Cusp-latitude Pc3 spectra: band-limited and power-law components

    Directory of Open Access Journals (Sweden)

    P. V. Ponomarenko

    Full Text Available This work attempts to fill a gap in comparative studies of upstream-generated Pc3–4 waves and broad band ULF noise observed at cusp latitudes. We performed a statistical analysis of the spectral properties of three years of cusp-latitude ground magnetometer data, finding that the average daytime Pc3–4 spectra are characterized by two principal components: an upstream-related band-limited enhancement (‘signal’ and a power-law background (‘noise’ with S(f a  f -4 . Based on this information we developed an algorithm allowing for the deconvolution of these two components in the spectral domain. The frequency of the signal enhancement increases linearly with IMF magnitude as f [mHz] ~ 4.4 | BIMF | [nT], and its power maximizes around IMF cone angles qxB ~ 20 and 160° and at 10:30–11:00 MLT. Both spectral components exhibit similar semiannual variations with equinoctial maxima. The back-ground noise power grows with increasing southward Bz and remains nearly constant for northward Bz . Its diurnal variation resembles that of Pc5 field-line resonance power, with a maximum near 09:00 MLT. Both the band-limited signal and broad band noise components show power-law growth with solar wind velocity a V 5.71sw and a V 4.12sw, respectively. Thus, the effective signal-to-noise ratio increases with in-creasing Vsw. The observations suggest that the noise generation is associated with reconnection processes.

    Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers; MHD waves and instabilities; solar wind magnetosphere interactions

  19. Recent publications on environmental law

    International Nuclear Information System (INIS)

    Lohse, S.

    1991-01-01

    The bibliography contains references to publications covering the following subject fields: General environmental law; environmental law in relation to constitutional law, administrative law, procedural law, revenue law, criminal law, private law, industrial law; law of regional development; nature conservation law; law on water protection; waste management law; law on protection against harmful effects on the environment; atomic energy law and radiation protection law; law of the power industry and the mining industry; laws and regulations on hazardous material and environmental hygiene. (orig.) [de

  20. Transition from Exponential to Power Law Income Distributions in a Chaotic Market

    Science.gov (United States)

    Pellicer-Lostao, Carmen; Lopez-Ruiz, Ricardo

    Economy is demanding new models, able to understand and predict the evolution of markets. To this respect, Econophysics offers models of markets as complex systems, that try to comprehend macro-, system-wide states of the economy from the interaction of many agents at micro-level. One of these models is the gas-like model for trading markets. This tries to predict money distributions in closed economies and quite simply, obtains the ones observed in real economies. However, it reveals technical hitches to explain the power law distribution, observed in individuals with high incomes. In this work, nonlinear dynamics is introduced in the gas-like model in an effort to overcomes these flaws. A particular chaotic dynamics is used to break the pairing symmetry of agents (i, j) ⇔ (j, i). The results demonstrate that a "chaotic gas-like model" can reproduce the Exponential and Power law distributions observed in real economies. Moreover, it controls the transition between them. This may give some insight of the micro-level causes that originate unfair distributions of money in a global society. Ultimately, the chaotic model makes obvious the inherent instability of asymmetric scenarios, where sinks of wealth appear and doom the market to extreme inequality.

  1. Featuring Control Power: Corporate Law and Economics Revisited

    NARCIS (Netherlands)

    A.M. Pacces (Alessio)

    2008-01-01

    textabstractThis dissertation reappraises the existing framework for economic analysis of corporate law. The standard approach to the legal foundations of corporate governance is based on the ‘law matters’ thesis, according to which corporate law promotes separation of ownership and control by

  2. Limitation of Power of the Counsel to Review the File in the Criminal Procedure: Law No. 6572 And It’s Consequences

    Directory of Open Access Journals (Sweden)

    Coşkun Koç

    2016-06-01

    Full Text Available The Article No. 153 of the Law of Criminal Procedure, which regulates the power of the counsel to examine the file, has been amended by the Law No. 6572, the Article No. 44, dated 02.12.2014. According to the amendment, if the power of the counsel to examine the content of the file or taking copies of the documents jeopardizes the purpose of the investigation, it can be limited by the judge upon request of the prosecutor. However, limiting the power of the counsel to examine the investigation file is against the European Convention on Human Rights and the Constitution. Indeed, the European Convention on Human Rights gives a ruling of violation of right in cases where it determines such a limitation of power. The power of the counsel to examine the content of the file is the sine qua non of a fair trial. It also serves the purpose of revealing the truth. In this study, we will try to examine the effect of the amendment made with the Article 44 of the Law No. 6572 about power of the counsel to examine the file on the fair trial principle.

  3. ‘No Blue’ White LED

    DEFF Research Database (Denmark)

    Ou, Haiyan; Corell, Dennis Dan; Dam-Hansen, Carsten

    2010-01-01

    This paper explored the feasibility of making a white LED light source by color mixing method without using the blue color. This ‘no blue’ white LED has potential applications in photolithography room illumination, medical treatment and biophotonics research. A no-blue LED was designed......-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light source for photolithography room illumination due to its better color rendering in addition to energy efficiency, long life time and design flexibility. Additionally......, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation...

  4. Complex motion of a vehicle through a series of signals controlled by power-law phase

    Science.gov (United States)

    Nagatani, Takashi

    2017-07-01

    We study the dynamic motion of a vehicle moving through the series of traffic signals controlled by the position-dependent phase of power law. All signals are controlled by both cycle time and position-dependent phase. The dynamic model of the vehicular motion is described in terms of the nonlinear map. The vehicular motion varies in a complex manner by varying cycle time for various values of the power of the position-dependent phase. The vehicle displays the periodic motion with a long cycle for the integer power of the phase, while the vehicular motion exhibits the very complex behavior for the non-integer power of the phase.

  5. Power and Law in Enlightened Absolutism – Carl Gottlieb Svarez’ Theoretical and Practical Approach

    Directory of Open Access Journals (Sweden)

    Milan Kuhli

    2013-01-01

    Full Text Available The term Enlightened Absolutism reflects a certain tension between its two components. This tension is in a way a continuation of the dichotomy between power on one hand and law on the other. The present paper shall provide an analysis of these two concepts from the perspective of Carl Gottlieb Svarez, who, in his position as a high-ranking Prussian civil servant and legal reformist, had unparalleled influence on the legislative history of the Prussian states towards the end of the 18th century. Working side-by-side with Johann Heinrich Casimir von Carmer, who held the post of Prussian minister of justice from 1779 to 1798, Svarez was able to make use of his talent for reforming and legislating. From 1780 to 1794 he was primarily responsible for the elaboration of the codification of the Prussian private law – the »Allgemeines Landrecht für die Preußischen Staaten« in 1794. In the present paper, Svarez’ approach to the relation between law and power shall be analysed on two different levels. Firstly, on a theoretical level, the reformist’s thoughts and reflections as laid down in his numerous works, papers and memorandums, shall be discussed. Secondly, on a practical level, the question of the extent to which he implemented his ideas in Prussian legal reality shall be explored.

  6. Recent publications on environmental law

    International Nuclear Information System (INIS)

    Lohse, S.

    1988-01-01

    The bibliography contains 1235 references to publications covering the following subject fields: general environmental law; environmental law in relation to constitutional law, administrative law, procedural law, revenue law, criminal law, private law, industrial law; law of regional development; nature conservation law; law on water protection; waste management law; law on protection against harmful effects on the environment; atomic energy law and radiation protection law; law of the power industry and the mining industry; laws and regulations on hazardous material and environmental hygiene. (HP) [de

  7. Recent publications on environmental law

    International Nuclear Information System (INIS)

    Lohse, S.

    1989-01-01

    The bibliography contains 1160 references to publications covering the following subject fields: General environmental law; environmental law in relation to constitutional law, administrative law, procedural law, revenue law, criminal law, private law, industrial law; law of regional development; nature conservation law; law on water protection; waste management law; law on protection against harmful effects on the environment; atomic energy law and radiation protection law; law of the power industry and the mining industry; laws and regulations on hazardous material and environmental hygiene. (orig./HP) [de

  8. Forward Conduction Mode Controlled Piezoelectric Transformer-Based PFC LED Drive

    DEFF Research Database (Denmark)

    Roedgaard, M. S.; Weirich, M.; Andersen, M. A. E.

    2013-01-01

    Light-emitting diode (LED) illumination is getting more and more common; as LED's performance is rising, the price is falling and is getting competitive. Some of the challenges of ac mains supplied illumination are the requirement of power factor correction (PFC) and the competitiveness of a low...... priced market. In this paper, a new forward conduction mode (FCM) control method for piezoelectric transformer (PT)-based power converters is proposed. A PT-based LED drive facilitating passive PFC is developed, utilizing and validating the FCM control method. The drive utilizes an inductorless half...... LED drive has been developed, supplied from 230-V 50-Hz ac mains, achieving a power factor of 0.96....

  9. Strange, charmed and b-flavoured mesons in an effective power-law potential

    International Nuclear Information System (INIS)

    Barik, N.; Jena, S.N.

    1981-01-01

    We have shown that an effective non-coulombic power-law potenial, generating spin-dependence through scaler and vector exchanges in almost equal proportions along with zero quark-anomalous moment, which was found successful in earlier works for the fine-hyperfine splittings of heavy mesons like psi and T, can also describe very satisfactorily the S-wave hyperfine levels, M1-transition rates and electromagnetic mass difference of the strange, charmed and b-flavoured mesons. (orig.)

  10. Strange, charmed and b-flavoured mesons in an effective power-law potential

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N; Jena, S N [Utkal Univ., Bhubaneswar (India). Dept. of Physics

    1981-05-14

    We have shown that an effective non-coulombic power-law potenial, generating spin-dependence through scaler and vector exchanges in almost equal proportions along with zero quark-anomalous moment, which was found successful in earlier works for the fine-hyperfine splittings of heavy mesons like psi and T, can also describe very satisfactorily the S-wave hyperfine levels, M1-transition rates and electromagnetic mass difference of the strange, charmed and b-flavoured mesons.

  11. Study on the Thermal Resistance of Multi-chip Module High Power LED Packaging Heat Dissipation System

    Directory of Open Access Journals (Sweden)

    Kailin Pan

    2014-10-01

    Full Text Available Thermal resistance is a key technical index which indicates the thermal management of multi-chip module high power LED (MCM-LED packaging heat dissipation system. In this paper, the prototype structure of MCM-LED packaging heat dissipation system is proposed to study the reliable thermal resistance calculation method. In order to analyze the total thermal resistance of the MCM-LED packaging heat dissipation system, three kinds of thermal resistance calculation method including theoretical calculation, experimental testing and finite element simulation are developed respectively. Firstly, based on the thermal resistance network model and the principle of steady state heat transfer, the theoretical value of total thermal resistance is 6.111 K/W through sum of the thermal resistance of every material layer in the major direction of heat flow. Secondly, the thermal resistance experiment is carried out by T3Ster to obtain the experimental result of total thermal resistance, and the value is 6.729 K/W. Thirdly, a three-dimensional finite element model of MCM-LED packaging heat dissipation system is established, and the junction temperature experiment is also performed to calculated the finite element simulated result of total thermal resistance, the value is 6.99 K/W. Finally, by comparing the error of all the three kinds of result, the error of total thermal resistance between the theoretical value and experimental result is 9.2 %, and the error of total thermal resistance between the experimental result and finite element simulation is only about -3.9 %, meanwhile, the main reason of each error is discussed respectively.

  12. Power-Law Kinetics and Determinant Criteria for the Preclusion of Multistationarity in Networks of Interacting Species

    DEFF Research Database (Denmark)

    Wiuf, Carsten Henrik; Feliu, Elisenda

    2013-01-01

    is derived from the determinant of the Jacobian of the species formation rate function. Using this characterization, we further derive similar determinant criteria applicable to general sets of kinetics. The criteria are conceptually simple, computationally tractable, and easily implemented. Our approach...... embraces and extends previous work on multistationarity, such as work in relation to chemical reaction networks with dynamics defined by mass-action or noncatalytic kinetics, and also work based on graphical analysis of the interaction graph associated with the system. Further, we interpret the criteria...... and how the species influence each reaction. We characterize families of so-called power-law kinetics for which the associated species formation rate function is injective within each stoichiometric class and thus the network cannot exhibit multistationarity. The criterion for power-law kinetics...

  13. Bias-corrected Pearson estimating functions for Taylor's power law applied to benthic macrofauna data

    DEFF Research Database (Denmark)

    Jørgensen, Bent; Demétrio, Clarice G. B.; Kristensen, Erik

    2011-01-01

    Estimation of Taylor’s power law for species abundance data may be performed by linear regression of the log empirical variances on the log means, but this method suffers from a problem of bias for sparse data. We show that the bias may be reduced by using a bias-corrected Pearson estimating...

  14. Energy law. The legal boundary conditions of power supply. 2. rev. ed.; Grundriss zum Energierecht. Der rechtliche Rahmen fuer die Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlmacher, Gerd [E.ON Global Commodities SE, Duesseldorf (Germany); Stappert, Holger; Jansen, Guido (eds.) [Luther Rechtsanwaltsgesellschaft mbH, Duesseldorf (Germany); Schoon, Heike [BDEW Bundesverband der Energie- und Wasserwirtschaft e.V., Berlin (Germany)

    2015-11-01

    Now appearing in its second edition, this book presents a comprehensive overview of the legal framework governing the energy sector. It provides readily understandable coverage, across the relevant subfields of law, of the legal regulations applicable to any manner of activity in the energy sector along with a wealth of practical advice on the interpretation and application of legal provisions. The content has been thoroughly revised, updated to reflect the current status of legislation and supplemented with numerous chapters. The 2014 amendment of the Renewable Energy Law (EEG) and its practical impact have also been taken into account. The following topics are covered amongst others: unbundling of network operation; connection and access to networks and metering; network charges and incentive regulation; easement contracts; energy supply and basic services; energy and electricity taxes; cartel law, law on operating aids, procurement law; energy trade OTC and at exchanges; energy trade surveillance law; fuel production and fracking; conventional and nuclear power production; renewable energy production (including offshore production); energy storage and power-to-gas; transmission line construction; climate protection (including the 2014 EEG, emission trade and the Law on the Promotion of Renewable Energy in the Heat Sector); cogeneration law, district heating and contracting; and investment protection.

  15. Analysis of Power Laws, Shape Collapses, and Neural Complexity: New Techniques and MATLAB Support via the NCC Toolbox.

    Science.gov (United States)

    Marshall, Najja; Timme, Nicholas M; Bennett, Nicholas; Ripp, Monica; Lautzenhiser, Edward; Beggs, John M

    2016-01-01

    Neural systems include interactions that occur across many scales. Two divergent methods for characterizing such interactions have drawn on the physical analysis of critical phenomena and the mathematical study of information. Inferring criticality in neural systems has traditionally rested on fitting power laws to the property distributions of "neural avalanches" (contiguous bursts of activity), but the fractal nature of avalanche shapes has recently emerged as another signature of criticality. On the other hand, neural complexity, an information theoretic measure, has been used to capture the interplay between the functional localization of brain regions and their integration for higher cognitive functions. Unfortunately, treatments of all three methods-power-law fitting, avalanche shape collapse, and neural complexity-have suffered from shortcomings. Empirical data often contain biases that introduce deviations from true power law in the tail and head of the distribution, but deviations in the tail have often been unconsidered; avalanche shape collapse has required manual parameter tuning; and the estimation of neural complexity has relied on small data sets or statistical assumptions for the sake of computational efficiency. In this paper we present technical advancements in the analysis of criticality and complexity in neural systems. We use maximum-likelihood estimation to automatically fit power laws with left and right cutoffs, present the first automated shape collapse algorithm, and describe new techniques to account for large numbers of neural variables and small data sets in the calculation of neural complexity. In order to facilitate future research in criticality and complexity, we have made the software utilized in this analysis freely available online in the MATLAB NCC (Neural Complexity and Criticality) Toolbox.

  16. Active Power Filter DC Bus Voltage Piecewise Reaching Law Variable Structure Control

    Directory of Open Access Journals (Sweden)

    Baolian Liu

    2014-01-01

    Full Text Available The DC bus voltage stability control is one key technology to ensure that Active Power Filter (APF operates stably. The external disturbances such as power grid and load fluctuation and the system parameters changing may affect the stability of APF DC bus voltage and the normal operation of APF. The mathematical model of DC bus voltage is established according to power balance principle and a DC bus voltage piecewise reaching law variable structure control algorithm is proposed to solve the above problem, and the design method is given. The simulation and experiment results proved that the proposed variable structure control algorithm can eliminate the chattering problem existing in traditional variable structure control effectively, is insensitive to system disturbance, and has good robustness and fast dynamic response speed and stable DC bus voltage with small fluctuation. The above advantages ensure the compensation effect of APF.

  17. Provision of financial services, violation of public law conduct of business rules, and private law norm settinga Dutch, German, and European perspective

    NARCIS (Netherlands)

    Wallinga, Marnix

    2014-01-01

    Legal uncertainty exists with regards to the relationship between a violation of public law conduct of business rules and private law norm setting. In the area of financial services this uncertainty has led to the question whether private law duties of care can deviate from the norms pursuant to

  18. Power-law forgetting in synapses with metaplasticity

    International Nuclear Information System (INIS)

    Mehta, A; Luck, J M

    2011-01-01

    The idea of using metaplastic synapses to incorporate the separate storage of long- and short-term memories via an array of hidden states was put forward in the cascade model of Fusi et al. In this paper, we devise and investigate two models of a metaplastic synapse based on these general principles. The main difference between the two models lies in their available mechanisms of decay, when a contrarian event occurs after the build-up of a long-term memory. In one case, this leads to the conversion of the long-term memory to a short-term memory of the opposite kind, while in the other, a long-term memory of the opposite kind may be generated as a result. Appropriately enough, the response of both models to short-term events is not affected by this difference in architecture. On the contrary, the transient response of both models, after long-term memories have been created by the passage of sustained signals, is rather different. The asymptotic behaviour of both models is, however, characterised by power-law forgetting with the same universal exponent

  19. Mutually cooperative epidemics on power-law networks

    Science.gov (United States)

    Cui, Peng-Bi; Colaiori, Francesca; Castellano, Claudio

    2017-08-01

    The spread of an infectious disease can, in some cases, promote the propagation of other pathogens favoring violent outbreaks, which cause a discontinuous transition to an endemic state. The topology of the contact network plays a crucial role in these cooperative dynamics. We consider a susceptible-infected-removed-type model with two mutually cooperative pathogens: An individual already infected with one disease has an increased probability of getting infected by the other. We present a heterogeneous mean-field theoretical approach to the coinfection dynamics on generic uncorrelated power-law degree-distributed networks and validate its results by means of numerical simulations. We show that, when the second moment of the degree distribution is finite, the epidemic transition is continuous for low cooperativity, while it is discontinuous when cooperativity is sufficiently high. For scale-free networks, i.e., topologies with diverging second moment, the transition is instead always continuous. In this way we clarify the effect of heterogeneity and system size on the nature of the transition, and we validate the physical interpretation about the origin of the discontinuity.

  20. Consistency relation in power law G-inflation

    International Nuclear Information System (INIS)

    Unnikrishnan, Sanil; Shankaranarayanan, S.

    2014-01-01

    In the standard inflationary scenario based on a minimally coupled scalar field, canonical or non-canonical, the subluminal propagation of speed of scalar perturbations ensures the following consistency relation: r ≤ −8n T , where r is the tensor-to-scalar-ratio and n T is the spectral index for tensor perturbations. However, recently, it has been demonstrated that this consistency relation could be violated in Galilean inflation models even in the absence of superluminal propagation of scalar perturbations. It is therefore interesting to investigate whether the subluminal propagation of scalar field perturbations impose any bound on the ratio r/|n T | in G-inflation models. In this paper, we derive the consistency relation for a class of G-inflation models that lead to power law inflation. Within these class of models, it turns out that one can have r > −8n T or r ≤ −8n T depending on the model parameters. However, the subluminal propagation of speed of scalar field perturbations, as required by causality, restricts r ≤ −(32/3) n T

  1. High Output LED-Based Profile Lighting Fixture

    DEFF Research Database (Denmark)

    Török, Lajos; Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    Recent developments in power light emitting diode (LED) industry have made LEDs suitable for being efficiently used in high intensity lighting fixtures instead of the commonly used high intensity discharge (HID) lamps. A high output LEDbased profile-light fixture is presented in this paper...

  2. Evidence for two hard X-ray components in double power-law fits to the 1980 June 7 flare

    Science.gov (United States)

    Smith, Dean F.; Orwig, Larry E.

    1988-01-01

    The June 7, 1980 flare at 0312 UT was analyzed with double power-law fits on the basis of SMM hard X-ray burst spectrometer data. The flare is found to consist of seven peaks of characteristic time scale of about 8 sec followed by seven valleys which may contain significant peak components because of overlap. It is suggested that the possibility of thermal spectra for the peaks is unlikely. An investigation of the double power-law parameters through the third and fourth peaks revealed a hysteresis effect in the fourth peak. The present results have been interpreted in terms of a trap plus precipitation model.

  3. Law on the Decommissioning of unit 1 at the state enterprise of the Republic of Lithuania Ignalina Nuclear Power Plant

    International Nuclear Information System (INIS)

    2000-01-01

    This law regulates the legal principles for the decommissioning of unit 1 at the Ignalina Nuclear Power Plant. The main deadlines for the government in the preparation for the decommissioning are set in the law. All preparatory works should be finished before the year 2005

  4. Case law

    International Nuclear Information System (INIS)

    2016-01-01

    This section treats of the following case laws: 1 - Case Law France: Conseil d'etat decision, 22 February 2016, EDF v. Republic and Canton of Geneva relative to the Bugey nuclear power plant (No. 373516); United States: Brodsky v. US Nuclear Regulatory Commission, 650 Fed. Appx. 804 (2. Cir. 2016)

  5. Effective non-Coulombic power-law potential for the study of light and heavy mesons

    International Nuclear Information System (INIS)

    Barik, N.; Jena, S.N.

    1982-01-01

    From purely phenomenological considerations we have shown that it is possible to describe successfully the heavy meson spectra of cc-bar and bb-bar systems in the framework of an effective non-Coulombic power-law potential in the form V(r) = V 0 +ar/sup ν/ (with a,ν>0). The nonsingular short-distance behavior of this potential, which is in apparent contradiction with the predictions of quantum- chromodynamics, does not pose any problem in explaining the fine-hyperfine splitting, if we prescribe the spin dependence to be generated through this static confining potential in the form of an approximately equal admixture of scalar and vector parts with no contributions from the anomalous quark magnetic moments. This nonrelativistic formalsm, when extended to a unified study of the entire meson spectra including the ordinary light and the heavy mesons, gives a very good account of the meson masses, fine-hyperfine splittings, electromagnetic transition rates, and leptonic decay widths without reflecting any inadequacy in the short- and long-range behavior of this simple effective power-law potential

  6. Resurrecting the Power-law, Intermediate, and Logamediate Inflations in the DBI Scenario with Constant Sound Speed

    Science.gov (United States)

    Amani, Roonak; Rezazadeh, Kazem; Abdolmaleki, Asrin; Karami, Kayoomars

    2018-02-01

    We investigate the power-law, intermediate, and logamediate inflationary models in the framework of DBI non-canonical scalar field with constant sound speed. In the DBI setting, we first represent the power spectrum of both scalar density and tensor gravitational perturbations. Then, we derive different inflationary observables including the scalar spectral index n s , the running of the scalar spectral index {{dn}}s/d{ln}k, and the tensor-to-scalar ratio r. We show that the 95% CL constraint of the Planck 2015 T + E data on the non-Gaussianity parameter {f}{NL}{DBI} leads to the sound speed bound {c}s≥slant 0.087 in the DBI inflation. Moreover, our results imply that, although the predictions of the power-law, intermediate, and logamediate inflations in the standard canonical framework (c s = 1) are not consistent with the Planck 2015 data, in the DBI scenario with constant sound speed {c}srunning of the scalar spectral index and find that it is compatible with the 95% CL constraint from the Planck 2015 TT,TE,EE+lowP data.

  7. Existence of k⁻¹ power-law scaling in the equilibrium regions of wall-bounded turbulence explained by Heisenberg's eddy viscosity.

    Science.gov (United States)

    Katul, Gabriel G; Porporato, Amilcare; Nikora, Vladimir

    2012-12-01

    The existence of a "-1" power-law scaling at low wavenumbers in the longitudinal velocity spectrum of wall-bounded turbulence was explained by multiple mechanisms; however, experimental support has not been uniform across laboratory studies. This letter shows that Heisenberg's eddy viscosity approach can provide a theoretical framework that bridges these multiple mechanisms and explains the elusiveness of the "-1" power law in some experiments. Novel theoretical outcomes are conjectured about the role of intermittency and very-large scale motions in modifying the k⁻¹ scaling.

  8. THE FUNDAMENTAL SOLUTIONS FOR MULTI-TERM MODIFIED POWER LAW WAVE EQUATIONS IN A FINITE DOMAIN

    OpenAIRE

    Jiang, H.; Liu, F.; Meerschaert, M. M.; McGough, R. J.

    2013-01-01

    Fractional partial differential equations with more than one fractional derivative term in time, such as the Szabo wave equation, or the power law wave equation, describe important physical phenomena. However, studies of these multi-term time-space or time fractional wave equations are still under development.

  9. Power law behavior of RR-interval variability in healthy middle-aged persons, patients with recent acute myocardial infarction, and patients with heart transplants

    Science.gov (United States)

    Bigger, J. T. Jr; Steinman, R. C.; Rolnitzky, L. M.; Fleiss, J. L.; Albrecht, P.; Cohen, R. J.

    1996-01-01

    BACKGROUND. The purposes of the present study were (1) to establish normal values for the regression of log(power) on log(frequency) for, RR-interval fluctuations in healthy middle-aged persons, (2) to determine the effects of myocardial infarction on the regression of log(power) on log(frequency), (3) to determine the effect of cardiac denervation on the regression of log(power) on log(frequency), and (4) to assess the ability of power law regression parameters to predict death after myocardial infarction. METHODS AND RESULTS. We studied three groups: (1) 715 patients with recent myocardial infarction; (2) 274 healthy persons age and sex matched to the infarct sample; and (3) 19 patients with heart transplants. Twenty-four-hour RR-interval power spectra were computed using fast Fourier transforms and log(power) was regressed on log(frequency) between 10(-4) and 10(-2) Hz. There was a power law relation between log(power) and log(frequency). That is, the function described a descending straight line that had a slope of approximately -1 in healthy subjects. For the myocardial infarction group, the regression line for log(power) on log(frequency) was shifted downward and had a steeper negative slope (-1.15). The transplant (denervated) group showed a larger downward shift in the regression line and a much steeper negative slope (-2.08). The correlation between traditional power spectral bands and slope was weak, and that with log(power) at 10(-4) Hz was only moderate. Slope and log(power) at 10(-4) Hz were used to predict mortality and were compared with the predictive value of traditional power spectral bands. Slope and log(power) at 10(-4) Hz were excellent predictors of all-cause mortality or arrhythmic death. To optimize the prediction of death, we calculated a log(power) intercept that was uncorrelated with the slope of the power law regression line. We found that the combination of slope and zero-correlation log(power) was an outstanding predictor, with a

  10. Powerful subjects of tax law enforcement

    OpenAIRE

    Igor Dementyev

    2017-01-01

    УДК 342.6The subject. Competence of government bodies and their officials in the sphere of application of the tax law is considered in the article.The purpose of research is to determine the ratio of tax enforcement and application of the tax law, as well as the relationship between the concepts “party of tax enforcement” and “participant of tax legal relations”.Main results and scope of their application. The circle of participants of tax legal relations is broader than the circle of parties...

  11. Multitude scaling laws in axisymmetric turbulent wake

    Science.gov (United States)

    Layek, G. C.; Sunita

    2018-03-01

    We establish theoretically multitude scaling laws of a self-similar (statistical) axisymmetric turbulent wake. At infinite Reynolds number limit, the flow evolves as general power law and a new exponential law of streamwise distance, consistent with the criterion of equilibrium similarity hypothesis. We found power law scalings for components of the homogeneous dissipation rate (ɛ) obeying the non-Richardson-Kolmogorov cascade as ɛu˜ku3 /2/(l R elm ) , ɛv˜kv3 /2/l , kv˜ku/R el2 m, 0 stress, l is the local length scale, and Rel is the Reynolds number. The Richardson-Kolmogorov cascade corresponds to m = 0. For m ≈ 1, the power law agrees with non-equilibrium scaling laws observed in recent experiments of the axisymmetric wake. On the contrary, the exponential scaling law follows the above dissipation law with different regions of existence for power index m = 3. At finite Reynolds number with kinematic viscosity ν, scalings obey the dissipation laws ɛu ˜ νku/l2 and ɛv ˜ νkv/l2 with kv˜ku/R eln. The value of n is preferably 0 and 2. Different possibilities of scaling laws and symmetry breaking process are discussed at length.

  12. Fuselage mounted anti-collision lights utilizing high power LEDs

    Science.gov (United States)

    Lundberg, John; Machi, Nicolo; Mangum, Scott; Singer, Jeffrey

    2005-09-01

    As LEDs continue to improve in efficacy and total light output, they are increasingly finding their way in to new applications in the aviation industry as well as adjacent markets. One function that is particularly challenging and may reap substantial benefits from this new technology is the fuselage mounted anti-collision light. Anti-collision lights provide conspicuity for the aircraft by periodically emitting bright flashes of light. The color, light distribution and intensity levels for these lights are all closely regulated through Federal Aviation Regulation (FAR) documents. These lighting requirements, along with thermal, environmental and aerodynamic requirements, drive the overall design. In this paper, we will discuss the existing technologies used in anti-collision lights and the advantages and challenges associated with an LED solution. Particular attention will be given to the optical, thermal, electrical and aerodynamic aspects associated with an LED approach. A specific case study will be presented along with some of the challenges that have arisen during the design process. These challenges include the addition of an integrated covert anti-collision lighting.

  13. Treatment of surrogacyin Comparative Law.

    Directory of Open Access Journals (Sweden)

    Ángela Ruiz SÁENZ

    2016-01-01

    Full Text Available The progress in the life sciences and medicine driven by modern advances and discoveries of science and technology has led to the development of assisted reproductive technology as a solution to the problem of infertility, replacing adoption as a traditional alternative to biological parenthood. In this context, deserves special mention surrogacy by the disputes generated from a social standpoint, ethical, legal and biomedical. The disparate regulation of this practice into national law has led to the “reproductive tourism”, that is, the transfer of couples from countries where the practice of surrogacy is illegal in other countries where the practice is legal, leading private international law issues relating to the recognition of the parentage of children born through the use of these techniques.

  14. Development and future of ultraviolet light-emitting diodes: UV-LED will replace the UV lamp

    Science.gov (United States)

    Muramoto, Yoshihiko; Kimura, Masahiro; Nouda, Suguru

    2014-06-01

    Ultraviolet light-emitting diodes (UV-LEDs) have started replacing UV lamps. The power per LED of high-power LED products has reached 12 W (14 A), which is 100 times the values observed ten years ago. In addition, the cost of these high-power LEDs has been decreasing. In this study, we attempt to understand the technologies and potential of UV-LEDs.

  15. A generalized power-law scaling law for a two-phase imbibition in a porous medium

    KAUST Repository

    El-Amin, Mohamed

    2013-11-01

    Dimensionless time is a universal parameter that may be used to predict real field behavior from scaled laboratory experiments in relation to imbibition processes in porous media. Researchers work to nondimensionalize the time has been through the use of parameters that are inherited to the properties of the moving fluids and the porous matrix, which may be applicable to spontaneous imbibition. However, in forced imbibition, the dynamics of the process depends, in addition, on injection velocity. Therefore, we propose the use of scaling velocity in the form of a combination of two velocities, the first of which (the characteristic velocity) is defined by the fluid and the porous medium parameters and the second is the injection velocity, which is a characteristic of the process. A power-law formula is suggested for the scaling velocity such that it may be used as a parameter to nondimensionalize time. This may reduce the complexities in characterizing two-phase imbibition through porous media and works well in both the cases of spontaneous and forced imbibition. The proposed scaling-law is tested against some oil recovery experimental data from the literature. In addition, the governing partial differential equations are nondimensionalized so that the governing dimensionless groups are manifested. An example of a one-dimensional countercurrent imbibition is considered numerically. The calculations are carried out for a wide range of Ca and Da to illustrate their influences on water saturation as well as relative water/oil permeabilities. © 2013 Elsevier B.V.

  16. A generalized power-law scaling law for a two-phase imbibition in a porous medium

    KAUST Repository

    El-Amin, Mohamed; Salama, Amgad; Sun, Shuyu

    2013-01-01

    Dimensionless time is a universal parameter that may be used to predict real field behavior from scaled laboratory experiments in relation to imbibition processes in porous media. Researchers work to nondimensionalize the time has been through the use of parameters that are inherited to the properties of the moving fluids and the porous matrix, which may be applicable to spontaneous imbibition. However, in forced imbibition, the dynamics of the process depends, in addition, on injection velocity. Therefore, we propose the use of scaling velocity in the form of a combination of two velocities, the first of which (the characteristic velocity) is defined by the fluid and the porous medium parameters and the second is the injection velocity, which is a characteristic of the process. A power-law formula is suggested for the scaling velocity such that it may be used as a parameter to nondimensionalize time. This may reduce the complexities in characterizing two-phase imbibition through porous media and works well in both the cases of spontaneous and forced imbibition. The proposed scaling-law is tested against some oil recovery experimental data from the literature. In addition, the governing partial differential equations are nondimensionalized so that the governing dimensionless groups are manifested. An example of a one-dimensional countercurrent imbibition is considered numerically. The calculations are carried out for a wide range of Ca and Da to illustrate their influences on water saturation as well as relative water/oil permeabilities. © 2013 Elsevier B.V.

  17. Nuclear law and law of the sea - a synthesis

    International Nuclear Information System (INIS)

    Courteix, S.

    1976-01-01

    The general idea behind the work of the Paris Colloqium on Nuclear Law and Law of the Sea was that of an agreement and sometimes opposition between two specificities, that of the law of the maritime and, in particular, ocean environment, and that of the law of nuclear techniques. These relationships were studied notably in the perspective of the problems of transport of nuclear materials and their liability insurance, as well as from the viewpoint of the operation of nuclear powered ships. Another problem studied in this context is that of radioactive marine pollution. (N.E.A.) [fr

  18. Development and future of ultraviolet light-emitting diodes: UV-LED will replace the UV lamp

    International Nuclear Information System (INIS)

    Muramoto, Yoshihiko; Kimura, Masahiro; Nouda, Suguru

    2014-01-01

    Ultraviolet light-emitting diodes (UV-LEDs) have started replacing UV lamps. The power per LED of high-power LED products has reached 12 W (14 A), which is 100 times the values observed ten years ago. In addition, the cost of these high-power LEDs has been decreasing. In this study, we attempt to understand the technologies and potential of UV-LEDs. (invited article)

  19. Effective Power-Law Dependence of Lyapunov Exponents on the Central Mass in Galaxies

    Science.gov (United States)

    Delis, N.; Efthymiopoulos, C.; Kalapotharakos, C.

    2015-01-01

    Using both numerical and analytical approaches, we demonstrate the existence of an effective power-law relation L alpha m(sup p) between themean Lyapunov exponent L of stellar orbits chaotically scattered by a supermassive black hole (BH) in the centre of a galaxy and the mass parameter m, i.e. ratio of the mass of the BH over the mass of the galaxy. The exponent p is found numerically to obtain values in the range p approximately equals 0.3-0.5. We propose a theoretical interpretation of these exponents, based on estimates of local 'stretching numbers', i.e. local Lyapunov exponents at successive transits of the orbits through the BH's sphere of influence. We thus predict p = 2/3 - q with q approximately equaling 0.1-0.2. Our basic model refers to elliptical galaxy models with a central core. However, we find numerically that an effective power-law scaling of L with m holds also in models with central cusp, beyond a mass scale up to which chaos is dominated by the influence of the cusp itself. We finally show numerically that an analogous law exists also in disc galaxies with rotating bars. In the latter case, chaotic scattering by the BH affects mainly populations of thick tube-like orbits surrounding some low-order branches of the x(sub 1) family of periodic orbits, as well as its bifurcations at low-order resonances, mainly the inner Lindblad resonance and the 4/1 resonance. Implications of the correlations between L and m to determining the rate of secular evolution of galaxies are discussed.

  20. Refrigerating liquid prototype for LED's thermal management

    International Nuclear Information System (INIS)

    Faranda, Roberto; Guzzetti, Stefania; Lazaroiu, George Cristian; Leva, Sonia

    2012-01-01

    The heat management is the critical factor for high performance operation of LED. A new heat management application of refrigerating liquid integrated within a fabricated prototype is proposed and investigated. A series of experiments considering different heights of liquid level were performed to evaluate the heat dissipation performance and optical characteristics of the refrigerating liquid based prototype. The results reveal that the junction temperature decreases as the level of refrigerating liquid increases. The experimental results report that the refrigerating liquid reduces the junction temperature, and can positively influence the luminous radiation performances. An optimization investigation of the proposed solution was carried out to find an optimum thermal performance. The experiments indicated that refrigerating liquid cooling is a powerful way for heat dissipation of high power LEDs, and the fabrication of prototype was feasible and useful. - Highlights: ► New heat management application of refrigerating liquid on a fabricated LED prototype. ► Thermal models setup and comparison between the classical and the new solutions. ► The impact of refrigerating liquid level on LED thermal and luminous performances. ► The relationship between different levels of liquid with LED prototype performances.

  1. Electric power law: your working context for several decades. What must be known about the French law project

    International Nuclear Information System (INIS)

    Playe, D.

    1999-01-01

    The French government will adopt with some reticence the new organization of the electric power market as decided by the European parliament. The French transposition of the European legislative text will be discussed at the French national assembly only in February 1999 and voted only in the second semester. This paper summarizes the main points of the project of law passed in December 9, 1998 and tries to explain the stakes of the new regulatory context for Electricite de France (EdF): creation of a regulation commission, accounting dissociation between production, transport and distribution, the eligible customers, the tariffs of electricity transport, the disagreement between the government and the electric equipment professionals with respect to EdF's position, the social aspects, and the construction of direct power lines in complement of public networks. An interview of G. Poullain, head of the national council of the electric equipment (CNEE), about the future development of EdF is given in inset. (J.S.)

  2. In-Degree and PageRank of web pages: why do they follow similar power laws?

    NARCIS (Netherlands)

    Litvak, Nelli; Scheinhardt, Willem R.W.; Volkovich, Y.

    2009-01-01

    PageRank is a popularity measure designed by Google to rank Web pages. Experiments confirm that PageRank values obey a power law with the same exponent as In-Degree values. This paper presents a novel mathematical model that explains this phenomenon. The relation between PageRank and In-Degree is

  3. Hysteresis and Power-Law Statistics during temperature induced martensitic transformation

    International Nuclear Information System (INIS)

    Paul, Arya; Sengupta, Surajit; Rao, Madan

    2011-01-01

    We study hysteresis in temperature induced martensitic transformation using a 2D model solid exhibiting a square to rhombic structural transition. We find that upon quenching, the high temperature square phase, martensites are nucleated at sites having large non-affineness and ultimately invades the whole of the high temperature square phase. On heating the martensite, the high temperature square phase is restored. The transformation proceeds through avalanches. The amplitude and the time-duration of these avalanches exhibit power-law statistics both during heating and cooling of the system. The exponents corresponding to heating and cooling are different thereby indicating that the nucleation and dissolution of the product phase follows different transformation mechanism.

  4. Need for consent of a law extending the operating life of nuclear power plants

    International Nuclear Information System (INIS)

    Degenhart, Christoph

    2010-01-01

    The article deals with the question whether a law extending nuclear power plant life beyond the residual periods of time laid down in the law of April 22, 2002 requires consent of the Federal Council. The Atomic Energy Act needed the consent of the Federal Council pursuant to Article 87c, Basic Law, as its Section 24 determines that central functions of licensing and supervision be exercised by the federal states on behalf of the Federal Government. This has not changed after the current version of the norm. Increasing the residual quotas of electricity by amending Annex 3 of Sec.7, Para.1a, Atomic Energy Act, per se does not require consent. This is a substantive provision. Sec.24, Atomic Energy Act, does not need to be amended. The Federal Council, which consented to the original legislation, thus does not bear continued responsibility for the law. Every law must be treated as a separate entity in terms of legislative method. The Federal Council, with its first consent to the piece of legislation, ''approves'' this systemic shift. Renewed consent is required only in case of another systemic shift. This is the case when the provision about administrative responsibility takes on a very different meaning and impact no longer supported by the earlier consent. According to decisions by the Federal Constitutional Court, this expressly applies also to administration by commission. What is required is a comparison of administrative duties before and after entry into force of the amending law; mere quantitative shifts of administrative burdens do not cause a systemic shift. Whether the inclusion of backfitting obligations would be associated with regulations in administrative procedures has not been decided. In its ruling of May 4, 2010, the Federal Constitutional Court confirms that these do not require consent within the framework of Art.85 Para.1, Basic Law. (orig.)

  5. A TWO-COMPONENT POWER LAW COVERING NEARLY FOUR ORDERS OF MAGNITUDE IN THE POWER SPECTRUM OF SPITZER FAR-INFRARED EMISSION FROM THE LARGE MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Block, David L.; Puerari, Ivanio; Elmegreen, Bruce G.; Bournaud, Frederic

    2010-01-01

    Power spectra of Large Magellanic Cloud (LMC) emission at 24, 70, and 160 μm observed with the Spitzer Space Telescope have a two-component power-law structure with a shallow slope of -1.6 at low wavenumber, k, and a steep slope of -2.9 at high k. The break occurs at k -1 ∼ 100-200 pc, which is interpreted as the line-of-sight thickness of the LMC disk. The slopes are slightly steeper for longer wavelengths, suggesting the cooler dust emission is smoother than the hot emission. The power spectrum (PS) covers ∼3.5 orders of magnitude, and the break in the slope is in the middle of this range on a logarithmic scale. Large-scale driving from galactic and extragalactic processes, including disk self-gravity, spiral waves, and bars, presumably causes the low-k structure in what is effectively a two-dimensional geometry. Small-scale driving from stellar processes and shocks causes the high-k structure in a three-dimensional geometry. This transition in dimensionality corresponds to the observed change in PS slope. A companion paper models the observed power law with a self-gravitating hydrodynamics simulation of a galaxy like the LMC.

  6. Legality, separation of powers, stability of electoral law: The impact of new voting technologies

    OpenAIRE

    Driza Maurer, Ardita

    2016-01-01

    Legality, separation of powers and stability of electoral law are some of the principles of the European constitutional heritage. They should be respected and implemented throughout the electoral process, including when new voting technologies are used. This paper discusses e-voting specific implementations of the principles or challenges to it. Ongoing and proposed improvements in legislation or practice are pinpointed.

  7. The High-efficiency LED Driver for Visible Light Communication Applications.

    Science.gov (United States)

    Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

    2016-08-08

    This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system's efficiency of 80.8% can be achieved at 1-Mb/s data rate.

  8. 14 CFR 302.17 - Administrative law judges.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Administrative law judges. 302.17 Section... Evidentiary Hearing Proceedings § 302.17 Administrative law judges. (a) Powers and delegation of authority. (1) An administrative law judge shall have the following powers, in addition to any others specified in...

  9. Electroviscous effects in steady fully developed flow of a power-law liquid through a cylindrical microchannel

    International Nuclear Information System (INIS)

    Bharti, Ram P.; Harvie, Dalton J.E.; Davidson, Malcolm R.

    2009-01-01

    Electroviscous effects in steady, fully developed, pressure-driven flow of power-law liquids through a uniform cylindrical microchannel have been investigated numerically by solving the Poisson-Boltzmann and the momentum equations using a finite difference method. The pipe wall is considered to have uniform surface charge density and the liquid is assumed to be a symmetric 1:1 electrolyte solution. Electroviscous resistance reduces the velocity adjacent to the wall, relative to the velocity on the axis. The effect is shown to be greater when the liquid is shear-thinning, and less when it is shear-thickening, than it is for Newtonian flow. For overlapping electrical double layers and elevated surface charge density, the electroviscous reduction in the near-wall velocity can form an almost stationary (zero shear) layer there when the liquid is shear-thinning. In that case, the liquid behaves approximately as if it is flowing through a channel of reduced diameter. The induced axial electrical field shows only a weak dependence on the power-law index with the dependence being greatest for shear-thinning liquids. This field exhibits a local maximum as surface charge density increases from zero, even though the corresponding electrokinetic resistance increases monotonically. The magnitude of the electroviscous effect on the apparent viscosity, as measured by the ratio of the apparent and physical consistency indices, decreases monotonically as the power-law index increases. Thus, overall, the electroviscous effect is stronger in shear-thinning, and weaker in shear-thickening liquids, than it is when the liquid is Newtonian.

  10. A Hard X-Ray Power-Law Spectral Cutoff in Centaurus X-4

    DEFF Research Database (Denmark)

    Chakrabarty, Deepto; Tomsick, John A.; Grefenstette, Brian W.

    2015-01-01

    The low-mass X-ray binary Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unkno...... behavior with PSR J1023+0038, IGR J18245-2452, and XSS J12270-4859, which have shown transitions between LMXB and radio pulsar modes at a similar X-ray luminosity....

  11. Power-law distributions for a trapped ion interacting with a classical buffer gas.

    Science.gov (United States)

    DeVoe, Ralph G

    2009-02-13

    Classical collisions with an ideal gas generate non-Maxwellian distribution functions for a single ion in a radio frequency ion trap. The distributions have power-law tails whose exponent depends on the ratio of buffer gas to ion mass. This provides a statistical explanation for the previously observed transition from cooling to heating. Monte Carlo results approximate a Tsallis distribution over a wide range of parameters and have ab initio agreement with experiment.

  12. In-degree and pageRank of web pages: Why do they follow similar power laws?

    NARCIS (Netherlands)

    Litvak, Nelli; Scheinhardt, Willem R.W.; Volkovich, Y.

    The PageRank is a popularity measure designed by Google to rank Web pages. Experiments confirm that the PageRank obeys a 'power law' with the same exponent as the In-Degree. This paper presents a novel mathematical model that explains this phenomenon. The relation between the PageRank and In-Degree

  13. Network-state modulation of power-law frequency-scaling in visual cortical neurons.

    Science.gov (United States)

    El Boustani, Sami; Marre, Olivier; Béhuret, Sébastien; Baudot, Pierre; Yger, Pierre; Bal, Thierry; Destexhe, Alain; Frégnac, Yves

    2009-09-01

    Various types of neural-based signals, such as EEG, local field potentials and intracellular synaptic potentials, integrate multiple sources of activity distributed across large assemblies. They have in common a power-law frequency-scaling structure at high frequencies, but it is still unclear whether this scaling property is dominated by intrinsic neuronal properties or by network activity. The latter case is particularly interesting because if frequency-scaling reflects the network state it could be used to characterize the functional impact of the connectivity. In intracellularly recorded neurons of cat primary visual cortex in vivo, the power spectral density of V(m) activity displays a power-law structure at high frequencies with a fractional scaling exponent. We show that this exponent is not constant, but depends on the visual statistics used to drive the network. To investigate the determinants of this frequency-scaling, we considered a generic recurrent model of cortex receiving a retinotopically organized external input. Similarly to the in vivo case, our in computo simulations show that the scaling exponent reflects the correlation level imposed in the input. This systematic dependence was also replicated at the single cell level, by controlling independently, in a parametric way, the strength and the temporal decay of the pairwise correlation between presynaptic inputs. This last model was implemented in vitro by imposing the correlation control in artificial presynaptic spike trains through dynamic-clamp techniques. These in vitro manipulations induced a modulation of the scaling exponent, similar to that observed in vivo and predicted in computo. We conclude that the frequency-scaling exponent of the V(m) reflects stimulus-driven correlations in the cortical network activity. Therefore, we propose that the scaling exponent could be used to read-out the "effective" connectivity responsible for the dynamical signature of the population signals measured

  14. Heat Transfer Characteristics in High Power LED Packaging

    Directory of Open Access Journals (Sweden)

    Chi-Hung Chung

    2014-03-01

    Full Text Available This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and vertical type. The die attach method includes silver paste and the eutectic structure. The carrying substrates are aluminum oxide (Alumina and aluminum nitride (AIN ceramic substrates and metal core PCB (MCPCB. The experimental results show that, under the conditions of the same crystal grain and die attach method, the thermal resistance values for the AIN substrate and the Alumina substrate are 2.1K/W and 5.1K/W, respectively and the total thermal resistance values are 7.3K/W and 10.8K/W. Compared to the Alumina substrate, the AIN substrate can effectively lower the total thermal resistance value by 32.4%. This is because the heat transfer coefficient of the AIN substrate is higher than that of the Alumina substrate, thus effectively increasing its thermal conductivity. In addition, under the conditions of the same crystal grain and the same substrate, the packaging methods are using silver paste and the eutectic structure for die attach. Their thermal resistance values are 5.7K/W and 2.7K/W, respectively, with a variance of 3K/W. Comparisons of the crystal grain structure show that the thermal resistance for the flip chip type is lower than that of the traditional lateral type by 0.9K/W. This is because the light emitting layer of the flip chip crystal grain is closer to the heat-sink substrate, shortening the heat dissipation route, and thus lowering the thermal resistance value. For the total thermal resistance, the crystal grain structure has a lesser

  15. The US business cycle: power law scaling for interacting units with complex internal structure

    Science.gov (United States)

    Ormerod, Paul

    2002-11-01

    In the social sciences, there is increasing evidence of the existence of power law distributions. The distribution of recessions in capitalist economies has recently been shown to follow such a distribution. The preferred explanation for this is self-organised criticality. Gene Stanley and colleagues propose an alternative, namely that power law scaling can arise from the interplay between random multiplicative growth and the complex structure of the units composing the system. This paper offers a parsimonious model of the US business cycle based on similar principles. The business cycle, along with long-term growth, is one of the two features which distinguishes capitalism from all previously existing societies. Yet, economics lacks a satisfactory theory of the cycle. The source of cycles is posited in economic theory to be a series of random shocks which are external to the system. In this model, the cycle is an internal feature of the system, arising from the level of industrial concentration of the agents and the interactions between them. The model-in contrast to existing economic theories of the cycle-accounts for the key features of output growth in the US business cycle in the 20th century.

  16. Solutions and conservation laws of Benjamin–Bona–Mahony ...

    Indian Academy of Sciences (India)

    obtained with power-law and dual power-law nonlinearities. The Lie group analysis as ... The notion of conservation laws plays an important role in the solution process of differential ... For the theory and applications of Lie group analysis the ...

  17. Explaining the emergence of euthanasia law in the Netherlands: how the sociology of law can help the sociology of bioethics.

    Science.gov (United States)

    Weyers, Heleen

    2006-09-01

    The debate over the legalisation of voluntary euthanasia is most often seen to be the result of three changes in society: individualisation, diminished taboos concerning death and changes in the balance of power in medicine. The fact that these changes occurred in many western countries but led to legalisation in only a few makes this claim problematic. I examine whether socio-legal propositions, with respect to the emergence of laws which focus on social control, offer a better approach to understanding the development of rules allowing and governing euthanasia. After a short sketch of the history of the Dutch law regulating euthanasia, I discuss these three societal changes in the light of shifts in the social control of medical behaviour that shortens life. I show that the Dutch relaxation of the prohibition of euthanasia goes together with new forms of social control: doctors' self control is complemented with second-party control (by patients), professional third-party control and governmental control. My work calls attention to the fact that bioethics is part of larger systems of social control.

  18. Transient forced convection with viscous dissipation to power-law fluids in thermal entrance region of circular ducts with constant wall heat flux

    International Nuclear Information System (INIS)

    Dehkordi, Asghar Molaei; Mohammadi, Ali Asghar

    2009-01-01

    A numerical investigation was conducted on the transient behavior of a hydrodynamically, fully developed, laminar flow of power-law fluids in the thermally developing entrance region of circular ducts taking into account the effect of viscous dissipation but neglecting the effect of axial conduction. In this regard, the unsteady state thermal energy equation was solved by using a finite difference method, whereas the steady state thermal energy equation without wall heat flux was solved analytically as the initial condition of the former. The effects of the power-law index and wall heat flux on the local Nusselt number and thermal entrance length were investigated. Moreover, the local Nusselt number of steady state conditions was correlated in terms of the power-law index and wall heat flux and compared with literature data, which were obtained by an analytic solution for Newtonian fluids. Furthermore, a relationship was proposed for the thermal entrance length

  19. The influence of intrafamilial power on maternal health care in Mali: perspectives of women, men and mothers-in-law.

    Science.gov (United States)

    White, Darcy; Dynes, Michelle; Rubardt, Marcie; Sissoko, Koman; Stephenson, Rob

    2013-06-01

    Evidence from diverse settings suggests that women often have limited control over their own reproductive health decisions. To increase uptake of preventive services and behaviors, it is important to understand how intrafamilial power dynamics and the attitudes of women, their husband and their mother-in-law are associated with maternal health practices. In 317 households in two rural districts of central Mali, women who had given birth in the previous year, their husband and their mother-in-law each completed a survey gauging their attitudes toward constructs of gender, power and health. Bivariate and multivariable logistic regression analyses were conducted to identify associations with four maternal health outcomes: antenatal care frequency, antenatal care timing, institutional delivery and postnatal care. In multivariable analyses, the preferences and opinions of mothers-in-law were associated with the maternal health behaviors of their daughters-in-law. Women's own perceptions of their self-efficacy, the value of women in society and the quality of services at the local health facility were also independently associated with their preventive and health-seeking practices. Husbands' preferences and opinions were not associated with any outcome. Interventions focusing on women or couples may be insufficient to advance women's reproductive health in patriarchal societies such as Mali. Future research and programmatic efforts need to address gender norms and consider the influence of other family members, such as mothers-in-law.

  20. Flux decay during thermonuclear X-ray bursts analysed with the dynamic power-law index method

    Science.gov (United States)

    Kuuttila, J.; Kajava, J. J. E.; Nättilä, J.; Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E.; Cumming, A.; Poutanen, J.

    2017-08-01

    The cooling of type-I X-ray bursts can be used to probe the nuclear burning conditions in neutron star envelopes. The flux decay of the bursts has been traditionally modelled with an exponential, even if theoretical considerations predict power-law-like decays. We have analysed a total of 540 type-I X-ray bursts from five low-mass X-ray binaries observed with the Rossi X-ray Timing Explorer. We grouped the bursts according to the source spectral state during which they were observed (hard or soft), flagging those bursts that showed signs of photospheric radius expansion (PRE). The decay phase of all the bursts were then fitted with a dynamic power-law index method. This method provides a new way of probing the chemical composition of the accreted material. Our results show that in the hydrogen-rich sources the power-law decay index is variable during the burst tails and that simple cooling models qualitatively describe the cooling of presumably helium-rich sources 4U 1728-34 and 3A 1820-303. The cooling in the hydrogen-rich sources 4U 1608-52, 4U 1636-536, and GS 1826-24, instead, is clearly different and depends on the spectral states and whether PRE occurred or not. Especially the hard state bursts behave differently than the models predict, exhibiting a peculiar rise in the cooling index at low burst fluxes, which suggests that the cooling in the tail is much faster than expected. Our results indicate that the drivers of the bursting behaviour are not only the accretion rate and chemical composition of the accreted material, but also the cooling that is somehow linked to the spectral states. The latter suggests that the properties of the burning layers deep in the neutron star envelope might be impacted differently depending on the spectral state.

  1. Extraction of the power law exponent for 1 GeV/nucleon Au + C projectile multifragmentation

    International Nuclear Information System (INIS)

    Gilkes, M.L.; Elliott, J.B.; Huager, A.; Hirsch, A.S.; Hjort, E.

    1993-01-01

    Using moments of the measured charge distribution in exclusive gold multifragmentation events, we present a preliminary determination of the power law exponent τ. For a system undergoing a phase transition near the critical point, τ governs the cluster size distribution and is expected on rather general grounds to lie in the range 2 < τ < 3

  2. The system of legal regulations and supervisory powers in the German Atomic Energy Law

    International Nuclear Information System (INIS)

    Weber, K.H.

    1984-01-01

    The first part of the book deals with the practical implementation of the legal provisions governing examination and subsequent licensing and judicial restraint, and the effects of actual practice on the energy industry, for the purpose of showing the chain of cause and effect of the frequently lamented delays in the further utilisation of nuclear energy, and of analysing the role of the administrative courts in the process, pointing to the explosiveness in terms of economics of this issue. The second part analyses the risk assessments from the legal and technical point of view in order to ascertain whether the findings of risk assessments are suitable to serve as scale models for decisions to be taken by the courts. The third part is a critical evaluation of the numerous attempts to incorporate the general doctrine of discretionary power into the system of atomic energy law in a way conformable with the existing system. This analysis resulting in the statement that the attempts have failed so far, the fourth part of the book discusses the necessity to look for other solutions, among other things by critically screening the dogma of discretionary power. The author comes to the conclusion that judicial restraint is to be cut back in the licensing procedure, however not to the extent that control over the authorities is abandoned altogether, but rather in such a way that the power of administrative courts does not develop into judgments executing the law. It is to be avoided that licensing procedures for nuclear power plants degenerate into 'administrative procedures preceded by administrative procedures'. This may not be confounded with giving up all possibilities of legal protection. (orig./HSCH) [de

  3. Systematic study of β-band and correlation with g- band using power law and soft rotor formula

    International Nuclear Information System (INIS)

    Katoch, Vikas; Kaushik, Reetu; Sharma, S.; Gupta, J.B.

    2014-01-01

    The nuclear structure of even Z even N medium mass transitional nuclei consist of ground state band, K π =0 1 β-band, K π =2 1 γ- band and other higher bands. As we move away from closed shell, energy levels are low lying from spherical to deformed nuclei and energy deviated from ideal rotor behavior. The energy of these transitional nuclei in ground band can also be studied using Bohr Mottelson energy expression, Soft Rotor Formula (SRF), Power Law (PL) etc. Recently, Gupta et al. (2013) modified SRF for non zero band head K π =2 1 γ-band and reproduced the level energies. Here same formula applied for K π =0 1 β-band and the level energies are reproduced and compared with experimental energies. The power law is also used for recalculation of level energies and for useful comparison

  4. Recalling items from a category for 1 hour: an inquiry into power-law behavior and memory foraging.

    Science.gov (United States)

    Rhodes, Theo

    2013-07-01

    There are two complementary approaches to characterizing performance in a free recall task (retrieving items from a specified category). The historic, or top down approach, considers the overall structure of the produced responses, generally as the parameters of a fitted cumulative recall curve. Alternatively, free recall can be considered as a time series of recalls or inter-recall intervals. Earlier work employing this approach (Rhodes & Turvey, 2007) suggested power law behavior. Long trial durations (1 hour) are employed to more rigorously test for the presence of power law behavior and more generally, the hypothesis that the dynamics of free recall reflect complex, multiplicative processes. The outlined empirical methods are also employed to test predictions about the relative structure of differently sized categories. Consequences for an asymptotic curve based understanding of free recall and foraging metaphors of retrieval are discussed.

  5. Seasonal evolution of the Arctic marginal ice zone and its power-law obeying floe size distribution

    Science.gov (United States)

    Zhang, J.; Stern, H. L., III; Schweiger, A. J. B.; Steele, M.; Hwang, P. B.

    2017-12-01

    A thickness, floe size, and enthalpy distribution (TFED) sea ice model, implemented numerically into the Pan-arctic Ice-Ocean Modeling and Assimilation System (PIOMAS), is used to investigate the seasonal evolution of the Arctic marginal ice zone (MIZ) and its floe size distribution. The TFED sea ice model, by coupling the Zhang et al. [2015] sea ice floe size distribution (FSD) theory with the Thorndike et al. [1975] ice thickness distribution (ITD) theory, simulates 12-category FSD and ITD explicitly and jointly. A range of ice thickness and floe size observations were used for model calibration and validation. The model creates FSDs that generally obey a power law or upper truncated power law, as observed by satellites and aerial surveys. In this study, we will examine the role of ice fragmentation and lateral melting in altering FSDs in the Arctic MIZ. We will also investigate how changes in FSD impact the seasonal evolution of the MIZ by modifying the thermodynamic processes.

  6. Investigation of uniformity field generated from freeform lens with UV LED exposure system

    Science.gov (United States)

    Ciou, F. Y.; Chen, Y. C.; Pan, C. T.; Lin, P. H.; Lin, P. H.; Hsu, F. T.

    2015-03-01

    In the exposure process, the intensity and uniformity of light in the exposure area directly influenced the precision of products. UV-LED (Ultraviolet Light-Emitting Diode) exposure system was established to reduce the radiation leakage and increase the energy efficiency for energy saving. It is a trend that conventional mercury lamp could be replaced with UV-LED exposure system. This study was based on the law of conservation of energy and law of refraction of optical field distributing on the target plane. With these, a freeform lens with uniform light field of main exposure area could be designed. The light outside the exposure area could be concentrated into the area to improve the intensity of light. The refraction index and UV transmittance of Polydimethylsiloxane (PDMS) is 1.43 at 385 nm wavelength and 85-90%, respectively. The PDMS was used to fabricate the optics lens for UV-LEDs. The average illumination and the uniformity could be obtained by increasing the number of UV-LEDs and the spacing of different arrangement modes. After exposure process with PDMS lens, about 5% inaccuracy was obtained. Comparing to 10% inaccuracy of general exposure system, it shows that it is available to replace conventional exposure lamp with using UV-LEDs.

  7. Public Supervision over Private Relationships : Towards European Supervision Private Law?

    NARCIS (Netherlands)

    Cherednychenko, O.O.

    2014-01-01

    The rise of public supervision over private relationships in many areas of private law has led to the development of what, in the author’s view, could be called ‘European supervision private law’. This emerging body of law forms part of European regulatory private law and is made up of

  8. Study of LED layout in indoor visible light communication and performance analysis

    Science.gov (United States)

    Wang, Jiaan; Che, Ying; Wang, Xinlan; Guo, Linyang; Li, Jing

    2017-10-01

    Light emitting diodes(LED) could provide both illumination and data communication in indoor visible light communication(VLC) that owns the modulation bandwith from several from several MHz to seneral hundreds of MHz. The layout of LED plays an important role in maintaining a steady optical power distribution over the receiving plane. The existing rectangular LED layout does not provide a full coverage on the receiving plane leaving receiving optical power outage area, which in turn affects the best performance of the VLC system. This paper design a circular layout scheme of LED in 5mX5mX3m room based on the criterion of the illumination minimum mean square deviation. The influence of the distribution of the intensity of illumination with the radius of 1m and 1.5m,for including the wall reflection and not including the wall reflection, and make a comparison with rectangular LED layout of illumination distribution, when the number of LEDs with rectangular layout as same as circular layout. Including the number of LEDs are 4 and 16.For a specific simulation parameters as following:height of receiving plane is 0.85m,a single LEDs is composed of 60X60 LED chips, the parameters of a single chip is that transmitting power is 20mW,center luminous intensity is 0.73cd.semiangle at half power is 70deg.The parameters of concentrator is that photodiode area is 1cm2,photodiode responsivity is 0.4,field of view at the receiver is 85deg.Other parameters are that reflective index of concentrator is 1.5,reflectivity of wall is 0.8.Circular layout and rectangular layout are analyzed through simulation of the received optical power distribution, signal noise ratio distribution in non line of sight(including the wall reflection) and line of sight(not including the wall reflection),when the number of the LED is different. It is clear from the results that the received optical power distribution of non line of sight is better than line of sight, when the number of the LED are same, but

  9. Themes in nuclear law

    International Nuclear Information System (INIS)

    2003-01-01

    The nuclear law was analyzed during a workshop. The main aspects were: the law of population to access to information on nuclear energy and the relationship between the Regulator Organism and the nuclear power plants managers

  10. Flicker Reduction in LED-LCDs with Local Backlight

    DEFF Research Database (Denmark)

    Nadernejad, Ehsan; Mantel, Claire; Burini, Nino

    2013-01-01

    Local backlight dimming of LCD with LED backlight can reduce power consumption and improve quality of displayed images and videos. However, important variations of LED over time produce a visually annoying artifact called flickering. In this work, we propose a new algorithm to reduce flickering w...

  11. Design of a cylindrical LED substrate without radiator

    Science.gov (United States)

    Tang, Fan; Guo, Zhenning

    2017-12-01

    To reduce the weight and production costs of light-emitting diode (LED) lamps, we applied the principle of the chimney effect to design a cylindrical LED substrate without a radiator. We built a 3D model by using Solidworks software and applied the flow simulation plug-in to conduct model simulation, thereby optimizing the heat source distribution and substrate thickness. The results indicate that the design achieved optimal cooling with a substrate with an upper extension length of 35 mm, a lower extension length of 8 mm, and a thickness of 1 mm. For a substrate of those dimensions, the highest LED chip temperature was 64.78 °C, the weight of the substrate was 35.09 g, and R jb = 7.00 K/W. If the substrate is powered at 8, 10, and 12 W, its temperature meets LED safety requirements. In physical tests, the highest temperature for a physical 8 W cylindrical LED substrate was 66 °C, which differed by only 1.22 °C from the simulation results, verifying the validity of the simulation. The designed cylindrical LED substrate can be used in high-power LED lamps that do not require radiators. This design is not only excellent for heat dissipation, but also for its low weight, low cost, and simplicity of manufacture.

  12. Error diagrams and temporal correlations in a fracture model with characteristic and power-law distributed avalanches

    DEFF Research Database (Denmark)

    Moreno, Y.; Vázquez-Prada, M.; Pacheco, A.F.

    2003-01-01

    to the heterogeneity of the system. In one regime, a characteristic event is observed while for the second regime a power-law spectrum of avalanches is obtained reminiscent of self-organized criticality. We find that both regimes are different when predicting large avalanches and that, in the second regime...

  13. Classification of phase transitions of finite Bose-Einstein condensates in power law traps by Fisher zeros

    NARCIS (Netherlands)

    Mülken, O.; Borrmann, P.; Harting, J.D.R.; Stamerjohanns, H.

    2001-01-01

    We present a detailed description of a classification scheme for phase transitions in finite systems based on the distribution of Fisher zeros of the canonical partition function in the complex temperature plane. We apply this scheme to finite Bose systems in power-law traps within a semi-analytic

  14. Design of Programmable LED Controller with a Variable Current Source for 3D Image Display

    Directory of Open Access Journals (Sweden)

    Kyung-Ryang Lee

    2014-12-01

    Full Text Available Conventional fluorescent light sources, as well as incandescent light sources are gradually being replaced by Light Emitting Diodes (LEDs for reducing power consumption in the image display area for multimedia application. An LED light source requires a controller with a low-power operation. In this paper, a low-power technique using adiabatic operation is applied for the implementation of LED controller with a stable constant-current, a low-power and low-heat function. From the simulation result, the power consumption of the proposed LED controller using adiabatic operation was reduced to about 87% in comparison with conventional operation with a constant VDD. The proposed circuit is expected to be an alternative LED controller which is sensitive to external conditions such as heat.

  15. The Dawn of Criminal Law, Regulation of Punitive Power in the Sumerian, Akk adian and Semite Codes

    Directory of Open Access Journals (Sweden)

    Ramiro J. García Falconí

    2016-06-01

    Full Text Available General and special Law, the regulation of the punitive power appeared since the first codings known in the history of mankind, being clear their religious character, their sacrifice logic, and the violence element that permeate to it. This punitive matrix is found in both Sumerian and Akkadian Codes, as in the later Jewish legislation, in which violence and sacredness fuse. The Talion Law already makes its appearance, as well as the structures on which the Inquisitorial System will be later built, and some traits that survive until today.

  16. Higher-order superclustering in the Ostriker explosion scenario I. Three-point correlation functions of clusters in the constant and power-law models

    International Nuclear Information System (INIS)

    Jing Yipeng.

    1989-08-01

    We study the three-point correlation functions ρ(r, u, v) of clusters in the two types of explosion models by numerical simulations. The clusters are identified as the ''knots'' where three shells intersect. The shells are assumed to have the constant radii (the constant models) or have the power law radius distributions (the power law models). In both kinds of models, we find that ρ can be approximately expressed by the scaling form: ρ = Q(ξ 1 ξ 2 + ξ 2 ξ 3 + ξ 3 ξ 1 ), and Q is about 1, which are consistent with the observations. More detailed studies of r-, u- and v-dependences of Q show that Q remains constant in the constant models. In the power-law models, Q is independent of the shape parameters u and v, while it has some moderate r-dependences (variations with r about a factor of 1 or 2). (author). 27 refs, 9 figs

  17. A Novel Methodology for Measurements of an LED's Heat Dissipation Factor

    Science.gov (United States)

    Jou, R.-Y.; Haung, J.-H.

    2015-12-01

    Heat generation is an inevitable byproduct with high-power light-emitting diode (LED) lighting. The increase in junction temperature that accompanies the heat generation sharply degrades the optical output of the LED and has a significant negative influence on the reliability and durability of the LED. For these reasons, the heat dissipation factor, Kh, is an important factor in modeling and thermal design of LED installations. In this study, a methodology is proposed and experiments are conducted to determine LED heat dissipation factors. Experiments are conducted for two different brands of LED. The average heat dissipation factor of the Edixeon LED is 0.69, and is 0.60 for the OSRAM LED. By using the developed test method and comparing the results to the calculated luminous fluxes using theoretical equations, the interdependence of optical, electrical, and thermal powers can be predicted with a reasonable accuracy. The difference between the theoretical and experimental values is less than 9 %.

  18. 14th German nuclear law symposium

    International Nuclear Information System (INIS)

    Burgi, Martin

    2013-01-01

    Nuclear law is still relevant and topical. The nuclear power phase-out in response to the nuclear accident of Fukushima and the turnaround in German energy policy raise new legal issues. In several lectures of practioners and scientists the 14th German Nuclear Law Symposium examined questions regarding the retrofitting of nuclear power plants, their decommissioning and disposal, the current developements in the European nuclear and radiation protection law and the search for a final nuclear waste repository. The nuclear law provides examples for central challenges of administrative law, such as the independence of authorities and the protection of third parties. The discussions between the almost 150 participants are documented in several reports.

  19. Law, Contestation, and Power in the Global Political Economy: An Introduction.

    Directory of Open Access Journals (Sweden)

    Edward S. Cohen

    2013-10-01

    Full Text Available The papers included in this collection are part of concerted project to develop a political economy of law in the contemporary global system. Over the past two decades, scholars have noted the expanding role of law, legal institutions, and legal agents that have been part of the process of “globalization,” and have employed a number of frameworks to make sense of this process of legalization. A central theme of our project is that none of these frameworks has provided an adequate political economic analysis of the creation, diffusion, and use of law, and we present an alternative approach to advance the understanding of the turn to law across the many dimensions and sectors of the global system. The papers advance the analysis behind this approach and explore the various ways in which law matters in a variety of areas, including global finance, corporate governance, copyright, diplomacy, and the provision of security. Their goal is to advance our understanding of how law intersects with the mobilization of power in the construction of the contemporary political economy. Los trabajos incluidos en esta colección son parte de un proyecto conjunto para desarrollar una economía política de la ley en el sistema mundial contemporáneo. En las últimas dos décadas, los expertos han señalado el creciente papel de la ley, las instituciones legales, y los agentes judiciales que han sido parte del proceso de "globalización", y han empleado una serie de marcos para dar sentido a este proceso de legalización. Un tema central de nuestro proyecto es que ninguno de estos marcos ha proporcionado un adecuado análisis económico político de la creación, difusión y uso de la ley, y se presenta un enfoque alternativo para avanzar en la comprensión de la vuelta a la ley a través de las muchas dimensiones y sectores del sistema global. Los trabajos avanzan el análisis de este enfoque y exploran las diversas formas en que la ley importa en una variedad

  20. High-Voltage LED Light Engine with Integrated Driver

    Energy Technology Data Exchange (ETDEWEB)

    Soer, Wouter [Lumileds LLC, San Jose, CA (United States)

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

  1. Thermodynamics of charged rotating dilaton black branes with power-law Maxwell field

    International Nuclear Information System (INIS)

    Zangeneh, M.K.; Sheykhi, A.; Dehghani, M.H.

    2015-01-01

    In this paper, we construct a new class of charged rotating dilaton black brane solutions, with a complete set of rotation parameters, which is coupled to a nonlinear Maxwell field. The Lagrangian of the matter field has the form of the power-law Maxwell field. We study the causal structure of the spacetime and its physical properties in ample details. We also compute thermodynamic and conserved quantities of the spacetime, such as the temperature, entropy, mass, charge, and angular momentum. We find a Smarr-formula for the mass and verify the validity of the first law of thermodynamics on the black brane horizon. Finally, we investigate the thermal stability of solutions in both the canonical and the grand-canonical ensembles and disclose the effects of dilaton field and nonlinearity of the Maxwell field on the thermal stability of the solutions. We find that, for α ≤ 1, charged rotating black brane solutions are thermally stable independent of the values of the other parameters. For α > 1, the solutions can encounter an unstable phase depending on the metric parameters. (orig.)

  2. Knowledge about Implementation of the Law

    NARCIS (Netherlands)

    Boer, A.; van Engers, T.

    2011-01-01

    With good reason, legal positivism insists on a division between legal theory, addressing the sphere of law, and a sociology of power, addressing the sphere of power. The alignment between these spheres is a continuing source of friction, and a driver of change in the sphere of law. Because this

  3. Estimation of inflation parameters for Perturbed Power Law model using recent CMB measurements

    International Nuclear Information System (INIS)

    Mukherjee, Suvodip; Das, Santanu; Souradeep, Tarun; Joy, Minu

    2015-01-01

    Cosmic Microwave Background (CMB) is an important probe for understanding the inflationary era of the Universe. We consider the Perturbed Power Law (PPL) model of inflation which is a soft deviation from Power Law (PL) inflationary model. This model captures the effect of higher order derivative of Hubble parameter during inflation, which in turn leads to a non-zero effective mass m eff for the inflaton field. The higher order derivatives of Hubble parameter at leading order sources constant difference in the spectral index for scalar and tensor perturbation going beyond PL model of inflation. PPL model have two observable independent parameters, namely spectral index for tensor perturbation ν t and change in spectral index for scalar perturbation ν st to explain the observed features in the scalar and tensor power spectrum of perturbation. From the recent measurements of CMB power spectra by WMAP, Planck and BICEP-2 for temperature and polarization, we estimate the feasibility of PPL model with standard ΛCDM model. Although BICEP-2 claimed a detection of r=0.2, estimates of dust contamination provided by Planck have left open the possibility that only upper bound on r will be expected in a joint analysis. As a result we consider different upper bounds on the value of r and show that PPL model can explain a lower value of tensor to scalar ratio (r<0.1 or r<0.01) for a scalar spectral index of n s =0.96 by having a non-zero value of effective mass of the inflaton field m 2 eff /H 2 . The analysis with WP + Planck likelihood shows a non-zero detection of m 2 eff /H 2 with 5.7 σ and 8.1 σ respectively for r<0.1 and r<0.01. Whereas, with BICEP-2 likelihood m 2 eff /H 2  = −0.0237 ± 0.0135 which is consistent with zero

  4. The operation of nuclear power plants in the conflict between administrative law and criminal law

    International Nuclear Information System (INIS)

    Stubbe, C.

    1989-01-01

    The conflicting interests of administrative law and criminal law give rise to a number of burdensome conditions to be met by the operators of nuclear plants. Of course, it is one of the peculiarities of criminal law that nobody can decide for himself whether he wants to become involved in it. There is probably no other choice than meeting, with a good blend of composure and cleverness, the criteria now surrounding the operation of a nuclear facility. (orig.) [de

  5. Business and human rights: from soft law to hard law?

    Directory of Open Access Journals (Sweden)

    Ramona Elisabeta Cîrlig

    2016-12-01

    Full Text Available Over the last decades the international community turned its attention towards the impact that businesses have on human rights, and the role they can play in furt hering human rights protection, in light of the lead role they play in globalization, and the increasingly vocal allegations of human rights violations directed against some multinationals. These developments triggered some action at the United Nations, an d at the European Union level, and led to the development of international soft law in this area, moving slowly towards binding instruments. This paper explores the evolution of business and human rights, presents the current international non-binding instruments, as well as some states’ binding initiatives in this area, and highlights the tendency to move from soft law to hard law, to leave the realm of voluntary corporate responsibility for the one of pure accountability. In this context, several solutions are debated by scholars: from a binding treaty, or a series of narrower treaties focused on specific areas, to a Model Law which could be used by states to enact laws imposing obligations on businesses within their jurisdictions, or even adding human rights in the international investment agreements and making use of the international arbitration as an enforcement mechanism.

  6. Validation of a power-law noise model for simulating small-scale breast tissue

    International Nuclear Information System (INIS)

    Reiser, I; Edwards, A; Nishikawa, R M

    2013-01-01

    We have validated a small-scale breast tissue model based on power-law noise. A set of 110 patient images served as truth. The statistical model parameters were determined by matching the radially averaged power-spectrum of the projected simulated tissue with that of the central tomosynthesis patient breast projections. Observer performance in a signal-known exactly detection task in simulated and actual breast backgrounds was compared. Observers included human readers, a pre-whitening observer model and a channelized Hotelling observer model. For all observers, good agreement between performance in the simulated and actual backgrounds was found, both in the tomosynthesis central projections and the reconstructed images. This tissue model can be used for breast x-ray imaging system optimization. The complete statistical description of the model is provided. (paper)

  7. Highly excited bound-state resonances of short-range inverse power-law potentials

    Energy Technology Data Exchange (ETDEWEB)

    Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)

    2017-11-15

    We study analytically the radial Schroedinger equation with long-range attractive potentials whose asymptotic behaviors are dominated by inverse power-law tails of the form V(r) = -β{sub n}r{sup -n} with n > 2. In particular, assuming that the effective radial potential is characterized by a short-range infinitely repulsive core of radius R, we derive a compact analytical formula for the threshold energy E{sub l}{sup max} = E{sub l}{sup max}(n, β{sub n}, R), which characterizes the most weakly bound-state resonance (the most excited energy level) of the quantum system. (orig.)

  8. Power-law temperature dependence of the inelastic-scattering rate in disordered superconductors

    International Nuclear Information System (INIS)

    Devereaux, T.P.; Belitz, D.

    1991-01-01

    We present a theory of the quasiparticle inelastic lifetime τ in in disordered superconducting films. We find that both the Coulomb and the electron-phonon contribution to τ in -1 are enhanced by disorder, and that for reasonably strong electron-phonon coupling the latter is dominant. In contrast to clean superconductors, the scattering rate is larger than the recombination rate at all temperatures. This leads to a power-law temperature dependence of τ in -1 , in agreement with experimental observations. The theory quantitatively accounts for the magnitude, disorder dependence, and temperature dependence of τ in measured in recent experiments

  9. Power-Law Scaling of the Impact Crater Size-Frequency Distribution on Pluto: A Preliminary Analysis Based on First Images from New Horizons' Flyby

    Directory of Open Access Journals (Sweden)

    Scholkmann F.

    2016-01-01

    Full Text Available The recent (14 th July 2015 flyby of NASA’s New Horizons spacecraft of the dwarf planet Pluto resulted in the first high-resolution images of the geological surface- features of Pluto. Since previous studies showed that the impact crater size-frequency distribution (SFD of different celestial objects of our solar system follows power-laws, the aim of the present analysis was to determine, for the first time, the power-law scaling behavior for Pluto’s crater SFD based on the first images available in mid-September 2015. The analysis was based on a high-resolution image covering parts of Pluto’s re- gions Sputnik Planum , Al-Idrisi Montes and Voyager Terra . 83 impact craters could be identified in these regions and their diameter ( D was determined. The analysis re- vealed that the crater diameter SFD shows a statistically significant power-law scaling ( α = 2.4926±0.3309 in the interval of D values ranging from 3.75±1.14 km to the largest determined D value in this data set of 37.77 km. The value obtained for the scaling coefficient α is similar to the coefficient determined for the power-law scaling of the crater SFDs from the other celestial objects in our solar system. Further analysis of Pluto’s crater SFD is warranted as soon as new images are received from the spacecraft.

  10. Analysis of projectile motion: A comparative study using fractional operators with power law, exponential decay and Mittag-Leffler kernel

    Science.gov (United States)

    Gómez-Aguilar, J. F.; Escobar-Jiménez, R. F.; López-López, M. G.; Alvarado-Martínez, V. M.

    2018-03-01

    In this paper, the two-dimensional projectile motion was studied; for this study two cases were considered, for the first one, we considered that there is no air resistance and, for the second case, we considered a resisting medium k . The study was carried out by using fractional calculus. The solution to this study was obtained by using fractional operators with power law, exponential decay and Mittag-Leffler kernel in the range of γ \\in (0,1] . These operators were considered in the Liouville-Caputo sense to use physical initial conditions with a known physical interpretation. The range and the maximum height of the projectile were obtained using these derivatives. With the aim of exploring the validity of the obtained results, we compared our results with experimental data given in the literature. A multi-objective particle swarm optimization approach was used for generating Pareto-optimal solutions for the parameters k and γ for different fixed values of velocity v0 and angle θ . The results showed some relevant qualitative differences between the use of power law, exponential decay and Mittag-Leffler law.

  11. Scattering at low energies by potentials containing power-law corrections to the Coulomb interaction

    International Nuclear Information System (INIS)

    Kuitsinskii, A.A.

    1986-01-01

    The low-energy asymptotic behavior is found for the phase shifts and scattering amplitudes in the case of central potentials which decrease at infinity as n/r+ar /sup -a/,a 1. In problems of atomic and nuclear physics one is generally interested in collisions of clusters consisting of several charged particles. The effective interaction potential of such clusters contains long-range power law corrections to the Coulomb interaction that is presented

  12. Nuclear power use backed by EURATOM law. European Court of Justice ruling points the way ahead in cross-border litigation

    International Nuclear Information System (INIS)

    Schneider, Horst

    2010-01-01

    The Europeanization of nuclear safety has become highly evident with the adoption of the EURATOM Safety Directive of June 25, 2009. It will remain in the focus of public attention because its transposition into national law is to be completed by July 22, 2011. The subject of nuclear safety is treated also by the European Court of Justice (ECJ). The Court's rulings may even set the courses of events. It is not only EURATOM rules and regulations and secondary European law in the format of directives which are up for review, but also more extensive principles of European law. The main sources of dispute are the different nuclear energy policies and non-uniform safety regulations of member states. Cross-border events again and again trigger such disputes. One such constellation constitutes the background to the latest ECJ ruling of October 27, 2009 about nuclear safety and radiation protection. Action before an Austrian court was brought against a nuclear power plant situated in the Czech Republic and licensed by Czech authorities. Cessation of emissions of hazardous ionizing radiation by that plant and, thus, ultimately shutdown of that plant were demanded. The special feature of the case is the fact that the action was filed with an Austrian (civil) court and heard there. As the ECJ had commented in 2006 on a procedural question before legal proceedings were started, the issue at stake now was the right to bring action out of Austria against the nuclear power plant licensed in the Czech Republic. In Austrian law, there is no such right of cessation with respect to plants licensed in Austria, but only a right to claim damages. Against this background some thoughts are expressed about, and forecasts attempted of, European nuclear and radiation protection law. In this assessment, the difficult, multifaceted issues of European law rank second to the explanations of practical consequences for the development of nuclear power in EU member states. (orig.)

  13. Monolithic blue LED series arrays for high-voltage AC operation

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping [Satellite Venture Business Laboratory, University of Tokushima, Tokushima 770-8506 (Japan); Sato, Hisao; Mizobuchi, Takashi; Morioka, Kenji; Kawano, Shunsuke; Muramoto, Yoshihiko; Sato, Daisuke; Sakai, Shiro [Nitride Semiconductor Co. Ltd., Naruto, Tokushima 771-0360 (Japan); Lee, Young-Bae; Ohno, Yasuo [Department of Electrical and Electronic Engineering, University of Tokushima, Tokushima 770-8506 (Japan)

    2002-12-16

    Design and fabrication of monolithic blue LED series arrays that can be operated under high ac voltage are described. Several LEDs, such as 3, 7, and 20, are connected in series and in parallel to meet ac operation. The chip size of a single device is 150 {mu}m x 120 {mu}m and the total size is 1.1 mm x 1 mm for a 40(20+20) LED array. Deep dry etching was performed as device isolation. Two-layer interconnection and air bridge are utilized to connect the devices in an array. The monolithic series array exhibit the expected operation function under dc and ac bias. The output power and forward voltage are almost proportional to LED numbers connected in series. On-wafer measurement shows that the output power is 40 mW for 40(20+20) LED array under ac 72 V. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  14. Time-domain simulation of constitutive relations for nonlinear acoustics including relaxation for frequency power law attenuation media modeling

    Science.gov (United States)

    Jiménez, Noé; Camarena, Francisco; Redondo, Javier; Sánchez-Morcillo, Víctor; Konofagou, Elisa E.

    2015-10-01

    We report a numerical method for solving the constitutive relations of nonlinear acoustics, where multiple relaxation processes are included in a generalized formulation that allows the time-domain numerical solution by an explicit finite differences scheme. Thus, the proposed physical model overcomes the limitations of the one-way Khokhlov-Zabolotskaya-Kuznetsov (KZK) type models and, due to the Lagrangian density is implicitly included in the calculation, the proposed method also overcomes the limitations of Westervelt equation in complex configurations for medical ultrasound. In order to model frequency power law attenuation and dispersion, such as observed in biological media, the relaxation parameters are fitted to both exact frequency power law attenuation/dispersion media and also empirically measured attenuation of a variety of tissues that does not fit an exact power law. Finally, a computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the finite difference scheme, and, on the other hand, improve stability trough artificial attenuation when shock waves are present. This technique avoids the use of high-order finite-differences schemes leading to fast calculations. The present algorithm is especially suited for practical configuration where spatial discontinuities are present in the domain (e.g. axisymmetric domains or zero normal velocity boundary conditions in general). The accuracy of the method is discussed by comparing the proposed simulation solutions to one dimensional analytical and k-space numerical solutions.

  15. Two phase interleaved buck converter for driving high power LEDs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

  16. Health care law versus constitutional law.

    Science.gov (United States)

    Hall, Mark A

    2013-04-01

    National Federation of Independent Business v. Sebelius, the Supreme Court's ruling on the Patient Protection and Affordable Care Act, is a landmark decision - both for constitutional law and for health care law and policy. Others will study its implications for constitutional limits on a range of federal powers beyond health care. This article considers to what extent the decision is also about health care law, properly conceived. Under one view, health care law is the subdiscipline that inquires how courts and government actors take account of the special features of medicine that make legal or policy issues especially problematic - rather than regarding health care delivery and finance more generically, like most any other economic or social enterprise. Viewed this way, the opinions from the Court's conservative justices are mainly about general constitutional law principles. In contrast, Justice Ruth Bader Ginsburg's dissenting opinion for the four more liberal justices is just as much about health care law as it is about constitutional law. Her opinion gives detailed attention to the unique features of health care finance and delivery in order to inform her analysis of constitutional precedents and principles. Thus, the Court's multiple opinions give a vivid depiction of the compelling contrasts between communal versus individualistic conceptions of caring for those in need, and between health care and health insurance as ordinary commodities versus ones that merit special economic, social, and legal status.

  17. Network-state modulation of power-law frequency-scaling in visual cortical neurons.

    Directory of Open Access Journals (Sweden)

    Sami El Boustani

    2009-09-01

    Full Text Available Various types of neural-based signals, such as EEG, local field potentials and intracellular synaptic potentials, integrate multiple sources of activity distributed across large assemblies. They have in common a power-law frequency-scaling structure at high frequencies, but it is still unclear whether this scaling property is dominated by intrinsic neuronal properties or by network activity. The latter case is particularly interesting because if frequency-scaling reflects the network state it could be used to characterize the functional impact of the connectivity. In intracellularly recorded neurons of cat primary visual cortex in vivo, the power spectral density of V(m activity displays a power-law structure at high frequencies with a fractional scaling exponent. We show that this exponent is not constant, but depends on the visual statistics used to drive the network. To investigate the determinants of this frequency-scaling, we considered a generic recurrent model of cortex receiving a retinotopically organized external input. Similarly to the in vivo case, our in computo simulations show that the scaling exponent reflects the correlation level imposed in the input. This systematic dependence was also replicated at the single cell level, by controlling independently, in a parametric way, the strength and the temporal decay of the pairwise correlation between presynaptic inputs. This last model was implemented in vitro by imposing the correlation control in artificial presynaptic spike trains through dynamic-clamp techniques. These in vitro manipulations induced a modulation of the scaling exponent, similar to that observed in vivo and predicted in computo. We conclude that the frequency-scaling exponent of the V(m reflects stimulus-driven correlations in the cortical network activity. Therefore, we propose that the scaling exponent could be used to read-out the "effective" connectivity responsible for the dynamical signature of the population

  18. A power-law coupled three-form dark energy model

    Science.gov (United States)

    Yao, Yan-Hong; Yan, Yang-Jie; Meng, Xin-He

    2018-02-01

    We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and neglecting the potential term of dark energy, we obtain three solutions of the autonomous system of evolution equations, including a de Sitter attractor, a tracking solution and an approximate solution. To understand the strength of the coupling, we confront the model with the latest Type Ia Supernova, Baryon Acoustic Oscillations and Cosmic Microwave Background radiation observations, with the conclusion that the combination of these three databases marginalized over the present dark matter density parameter Ω _{m0} and the present three-form field κ X0 gives stringent constraints on the coupling constant, - 0.017< λ <0.047 (2σ confidence level), by which we present the model's applicable parameter range.

  19. A power-law coupled three-form dark energy model

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yan-Hong; Yan, Yang-Jie; Meng, Xin-He [Nankai University, Department of Physics, Tianjin (China)

    2018-02-15

    We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and neglecting the potential term of dark energy, we obtain three solutions of the autonomous system of evolution equations, including a de Sitter attractor, a tracking solution and an approximate solution. To understand the strength of the coupling, we confront the model with the latest Type Ia Supernova, Baryon Acoustic Oscillations and Cosmic Microwave Background radiation observations, with the conclusion that the combination of these three databases marginalized over the present dark matter density parameter Ω{sub m0} and the present three-form field κX{sub 0} gives stringent constraints on the coupling constant, -0.017 < λ < 0.047 (2σ confidence level), by which we present the model's applicable parameter range. (orig.)

  20. Islamic Law

    OpenAIRE

    Doranda Maracineanu

    2009-01-01

    The law system of a State represents the body of rules passed or recognized by that State inorder to regulate the social relationships, rules that must be freely obeyed by their recipients, otherwisethe State intervening with its coercive power. Throughout the development of the society, pedants havebeen particularly interested in the issue of law systems, each supporting various classifications; theclassification that has remained is the one distinguishing between the Anglo-Saxon, the Roman-...

  1. Analysis of precipitation characteristics of South and North China based on the power-law tail exponents

    International Nuclear Information System (INIS)

    Feng Guolin; Zhang Daquan; Gong Zhiqiang; Zhi Rong

    2008-01-01

    Precipitation sequence is a typical nonlinear and chaotic observational series, and studies on precipitation forecasts are restricted to the use of traditional linear statistical methods, especially when analysing the regional characteristics of precipitation. In the context of 20 stations' daily precipitation series (from 1956 to 2000) in South China (SC) and North China (NC), we divide each precipitation series into many self-stationary segments by using the heuristic segmentation algorithm (briefly BG algorithm). For each station's precipitation series, we calculate the exponent of power-law tail (EPT) of the cumulative probability distribution of segments with a length larger than l for precipitation and temperature series. Our results show that the power-law decay of the cumulative probability distribution of stationary segments might be a common attribution for precipitation and other nonstationary time series; the EPT somewhat indicates the precipitation duration and its spatial distribution that might be different from area to area. The EPT in NC is larger than in SC; Meanwhile, EPT might be another effective way to study the abrupt changes in nonlinear and nonstationary time series. (geophysics, astronomy and astrophysics)

  2. Applicability of the ''review of content'' under the law on standard terms and conditions to power availability and power supply contracts between producers and resellers; Die Anwendbarkeit der AGB-rechtlichen Inhaltskontrolle auf Leistungsvorhaltungs- und Stromliefervertraege zwischen Erzeuger und Weiterverkaeufer

    Energy Technology Data Exchange (ETDEWEB)

    Putzka, Florian

    2009-07-01

    This study deals with the applicability under the law on standard terms and conditions of the ''review of content'' to power availability and power supply contracts between producers and resellers. It addresses fundamental issues concerning the encroachment on the private autonomy of those involved as well as the hazard to the contract certainty of their contracts that is posed by the instrument of judicial review of content under the law on standard terms and conditions. The purpose of the study is to determine to what extent power availability and power supply contracts between producers and resellers are subject to a review of content by a civil judge, be it on the strength of the law on standard terms and conditions or through what is known as an extended review of content. Power supply contracts between power suppliers and final customers are left out of consideration here, even though the authors are aware of the fact that as a result of the amendment to the Energy Economy Law in 2005 and the ordinances following in its wake it is becoming more and more common for such contracts to be amenable to the law on standard terms and conditions.

  3. POWERED LED LIGHTING SUPPLIED FROM PV CELLS

    Directory of Open Access Journals (Sweden)

    Tirshu M.

    2011-12-01

    Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

  4. White LED visible light communication technology research

    Science.gov (United States)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  5. Design definition of the Laser Atmospheric Wind Sounder (LAWS), phase 2. Volume 1: Executive summary

    Science.gov (United States)

    1992-01-01

    The LAWS phase 1 and phase 2 studies have been completed on schedule and have led to significant advances in CO2 laser development. The Phase 2 Design Definition Study has shown that a large scanning mirror/high pulse energy laser LAWS Instrument is feasible and within the existing technology. The capability to monitor wind velocities with backscatter ratios of 10(exp 11) m(exp -1) SR(exp -1) is feasible. The weight budget allocated for the baseline LAWS is adequate, and sufficient reserves exist with the potential downsized configuration. With the possible decrease in available power from the baseline of 2.2 kW guideline, power and shot management is critical for the baseline configuration (15 to 20 J). This is particularly true during the 100 day occultation period each year. With the downsized configurations (5 to 7 J), power management is still necessary during the occultation but is primarily limited to shot management over the polar regions. The breadboard effort has produced significant laser advances for a tight 18 month schedule and the minimum budgets available from NASA, Lockheed, and TDS. Using the NASA funds and Lockheed and TDS fixed assets budgets, the breadboard was designed, fabricated, and brought on-line with first laser light within 16 months after ATP. First laser beam was obtained on 21 April 1992 at a 5 J power level. Tests since then have been conducted at sustained, repetitive pulse levels of over 7 J and 20 Hz. This is an increase of over two or three times greater than any system previously developed from this type laser. Increased power levels and additional life tests will be accomplished in the next LAWS phase. The Lockheed LAWS design will operate in the gravity gradient mode on-orbit, and all possible instrument vibration and jitter modes have been considered. Adequate pointing stability and control is state-of-the-art technology for the critical time periods, frequency rates, and control responses required by LAWS. Lockheed

  6. LED deep UV source for charge management of gravitational reference sensors

    International Nuclear Information System (INIS)

    Sun Kexun; Allard, Brett; Buchman, Saps; Williams, Scott; Byer, Robert L

    2006-01-01

    Proof mass electrical charge management is an important functionality for the ST-7-LTP technology demonstration flight and for LISA. Photoemission for charge control is accomplished by using deep ultraviolet (UV) light to excite photoelectron emission from an Au alloy. The conventional UV source is a mercury vapour lamp. We propose and demonstrate charge management using a deep UV light emitting diode (LED) source. We have acquired selected AlGaN UV LEDs, characterized their performance and successfully used them to realize charge management. The UV LEDs emit at a 257 nm central wavelength with a bandwidth of ∼12 nm. The UV power for a free-space LED is ∼120 μW, and after fibre coupling is ∼16 μW, more than sufficient for LISA applications. We have directly observed the LED UV light-induced photocurrent response from an Au photocathode and an Au-coated GRS/ST-7 proof mass. We demonstrated fast switching of UV LEDs and associated fast changes in photocurrent. This allows modulation and continuous discharge to meet stringent LISA disturbance reduction requirements. We propose and demonstrate AC charge management outside the gravitational wave signal band. Further, the megahertz bandwidth for UV LED switching allows for up to six orders of magnitude dynamic power range and a number of novel modes of operations. The UV LED based charge management system offers the advantages of small-size, lightweight, fibre-coupled operation with very low power consumption

  7. Dentistry and criminal law.

    Science.gov (United States)

    Khoury, B S; Khoury, J N

    2017-09-01

    Criminal law in dentistry, as shaped and moulded by the prevailing views of society, defines what is or is not socially acceptable. It applies in both personal and professional contexts with the intended consequence of protecting the public from unacceptable conduct and potential imbalances of power. At its centre, a patient's consent plays a pivotal role in transforming unlawful conduct into lawful conduct. This literature review considers the current law and the trend of utilizing criminal law in addition to non-criminal law alternatives of reprimanding clinicians for failure to achieve consent in the course of dental practice. Dentists must appreciate this change and the prosecuting authority's increasing willingness to resort to criminal law. © 2017 Australian Dental Association.

  8. Energy-Saving Tunnel Illumination System Based on LED's Intelligent Control

    International Nuclear Information System (INIS)

    Guo Shanshan; Wu Lan; Gu Hanting; Jiang Shuixiu

    2011-01-01

    At present there is a lot of electric energy wastage in tunnel illumination, whose design is based on the maximum brightness outside and the maximum vehicle speed all year round. LED's energy consumption is low, and the control of its brightness is simple and effective. It can be quickly adjusted between 0-100% of its maximum brightness, and will not affect the service life. Therefore, using LED as tunnel's illumination source, we can achieve a good energy saving effect. According to real-time data acquisition of vehicle speed, traffic flow and brightness outside the tunnel, the auto real-time control of tunnel illumination can be achieved. And the system regulated the LED luminance by means of combination of LED power module and intelligent control module. The tunnel information was detected by inspection equipments, which included luminometer, vehicle detector, and received by RTU(Remote Terminal Unit), then synchronously transmitted to PC. After data processing, RTU emitted the dimming signal to the LED driver to adjust the brightness of LED. Despite the relatively high cost of high-power LED lights, the enormous energy-saving effect and the well-behaved controllability is beyond compare to other lighting devices.

  9. The first experimental confirmation of the fractional kinetics containing the complex-power-law exponents: Dielectric measurements of polymerization reactions

    Science.gov (United States)

    Nigmatullin, R. R.; Arbuzov, A. A.; Salehli, F.; Giz, A.; Bayrak, I.; Catalgil-Giz, H.

    2007-01-01

    For the first time we achieved incontestable evidence that the real process of dielectric relaxation during the polymerization reaction of polyvinylpyrrolidone (PVP) is described in terms of the fractional kinetic equations containing complex-power-law exponents. The possibility of the existence of the fractional kinetics containing non-integer complex-power-law exponents follows from the general theory of dielectric relaxation that has been suggested recently by one of the authors (R.R.N). Based on the physical/geometrical meaning of the fractional integral with complex exponents there is a possibility to develop a general theory of dielectric relaxation based on the self-similar (fractal) character of the reduced (averaged) microprocesses that take place in the mesoscale region. This theory contains some essential predictions related to existence of the non-integer power-law kinetics and the results of this paper can be considered as the first confirmation of existence of the kinetic phenomena that are described by fractional derivatives with complex-power-law exponents. We want to stress here that with the help of a new complex fitting function for the complex permittivity it becomes possible to describe the whole process for real and imaginary parts simultaneously throughout the admissible frequency range (30 Hz-13 MHz). The fitting parameters obtained for the complex permittivity function for three temperatures (70, 90 and 110 °C) confirm in general the picture of reaction that was known qualitatively before. They also reveal some new features, which improve the interpretation of the whole polymerization process. We hope that these first results obtained in the paper will serve as a good stimulus for other researches to find the traces of the existence of new fractional kinetics in other relaxation processes unrelated to the dielectric relaxation. These results should lead to the reconsideration and generalization of irreversibility and kinetic phenomena that

  10. On the interplay between short and long term memory in the power-law cross-correlations setting

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav

    2015-01-01

    Roč. 421, č. 1 (2015), s. 218-222 ISSN 0378-4371 R&D Projects: GA ČR(CZ) GP14-11402P Institutional support: RVO:67985556 Keywords : Power-law cross-correlations * Long term memory * Short term memory Subject RIV: AH - Economics Impact factor: 1.785, year: 2015 http://library.utia.cas.cz/separaty/2015/E/kristoufek-0452316.pdf

  11. High power deep UV-LEDs for analytical optical instrumentation

    Czech Academy of Sciences Publication Activity Database

    Li, Y.; Dvořák, Miloš; Nesterenko, P. N.; Nuchtavorn, N.; Macka, M.

    2018-01-01

    Roč. 255, č. 2 (2018), s. 1238-1243 ISSN 0925-4005 Institutional support: RVO:68081715 Keywords : deep UV Light emitting diodes (LEDs) * optical detection * portable analytical instrumentation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 5.401, year: 2016

  12. Taylor's law and body size in exploited marine ecosystems.

    Science.gov (United States)

    Cohen, Joel E; Plank, Michael J; Law, Richard

    2012-12-01

    Taylor's law (TL), which states that variance in population density is related to mean density via a power law, and density-mass allometry, which states that mean density is related to body mass via a power law, are two of the most widely observed patterns in ecology. Combining these two laws predicts that the variance in density is related to body mass via a power law (variance-mass allometry). Marine size spectra are known to exhibit density-mass allometry, but variance-mass allometry has not been investigated. We show that variance and body mass in unexploited size spectrum models are related by a power law, and that this leads to TL with an exponent slightly <2. These simulated relationships are disrupted less by balanced harvesting, in which fishing effort is spread across a wide range of body sizes, than by size-at-entry fishing, in which only fish above a certain size may legally be caught.

  13. Origin of Power Laws for Reactions at Metal Surfaces Mediated by Hot Electrons

    DEFF Research Database (Denmark)

    Olsen, Thomas; Schiøtz, Jakob

    2009-01-01

    A wide range of experiments have established that certain chemical reactions at metal surfaces can be driven by multiple hot-electron-mediated excitations of adsorbates. A high transient density of hot electrons is obtained by means of femtosecond laser pulses and a characteristic feature of such...... density functional theory and the delta self-consistent field method. With a simplifying assumption, the power law becomes exact and we obtain a simple physical interpretation of the exponent n, which represents the number of adsorbate vibrational states participating in the reaction....

  14. Company law as another beggar-my-neighbour policy : Blog

    NARCIS (Netherlands)

    Cremers, Jan

    2017-01-01

    In a Blog (Progressive-Economy@TASC), Jan Cremers (UvT) describes the paradigm change that took place in company law in the 1990s. Since the introduction of the European internal market, company law has been increasingly judged in terms of its impact on ‘competitiveness’. This has led to some

  15. Homotopy Perturbation Method for Creeping Flow of Non-Newtonian Power-Law Nanofluid in a Nonuniform Inclined Channel with Peristalsis

    Science.gov (United States)

    Abou-zeid, Mohamed Y.; Mohamed, Mona A. A.

    2017-09-01

    This article is an analytic discussion for the motion of power-law nanofluid with heat transfer under the effect of viscous dissipation, radiation, and internal heat generation. The governing equations are discussed under the assumptions of long wavelength and low Reynolds number. The solutions for temperature and nanoparticle profiles are obtained by using homotopy perturbation method. Results for the behaviours of the axial velocity, temperature, and nanoparticles as well as the skin friction coefficient, reduced Nusselt number, and Sherwood number with other physical parameters are obtained graphically and analytically. It is found that as the power-law exponent increases, both the axial velocity and temperature increase, whereas nanoparticles decreases. These results may have applicable importance in the research discussions of nanofluid flow in channels with small diameters under the effect of different temperature distributions.

  16. Spatial layout optimization design of multi-type LEDs lighting source based on photoelectrothermal coupling theory

    Science.gov (United States)

    Xue, Lingyun; Li, Guang; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    Multiple LED-based spectral synthesis technology has been widely used in the fields of solar simulator, color mixing, and artificial lighting of plant factory and so on. Generally, amounts of LEDs are spatially arranged with compact layout to obtain the high power density output. Mutual thermal spreading among LEDs will produce the coupled thermal effect which will additionally increase the junction temperature of LED. Affected by the Photoelectric thermal coupling effect of LED, the spectrum of LED will shift and luminous efficiency will decrease. Correspondingly, the spectral synthesis result will mismatch. Therefore, thermal management of LED spatial layout plays an important role for multi-LEDs light source system. In the paper, the thermal dissipation network topology model considering the mutual thermal spreading effect among the LEDs is proposed for multi-LEDs system with various types of power. The junction temperature increment cased by the thermal coupling has the great relation with the spatial arrangement. To minimize the thermal coupling effect, an optimized method of LED spatial layout for the specific light source structure is presented and analyzed. The results showed that layout of LED with high-power are arranged in the corner and low-power in the center. Finally, according to this method, it is convenient to determine the spatial layout of LEDs in a system having any kind of light source structure, and has the advantages of being universally applicable to facilitate adjustment.

  17. Ionic fluids with r-6 pair interactions have power-law electrostatic screening

    International Nuclear Information System (INIS)

    Kjellander, Roland; Forsberg, Bjoern

    2005-01-01

    The decay behaviour of radial distribution functions for large distances r is investigated for classical Coulomb fluids where the ions interact with an r -6 potential (e.g. a dispersion interaction) in addition to the Coulombic and the short-range repulsive potentials (e.g. a hard core). The pair distributions and the density-density (NN), charge-density (QN) and charge-charge (QQ) correlation functions are investigated analytically and by Monte Carlo simulations. It is found that the NN correlation function ultimately decays like r -6 for large r, just as it does for fluids of electroneutral particles interacting with an r -6 potential. The prefactor is proportional to the squared compressibility in both cases. The QN correlations decay in general like r -8 and the QQ correlations like r -10 in the ionic fluid. The average charge density around an ion decays generally like r -8 and the average electrostatic potential like r -6 . This behaviour is in stark contrast to the decay behaviour for classical Coulomb fluids in the absence of the r -6 potential, where all these functions decay exponentially for large r. The power-law decays are, however, the same as for quantum Coulomb fluids. This indicates that the inclusion of the dispersion interaction as an effective r -6 interaction potential in classical systems yields the same decay behaviour for the pair correlations as in quantum ionic systems. An exceptional case is the completely symmetric binary electrolyte for which only the NN correlation has a power-law decay but not the QQ correlations. These features are shown by an analysis of the bridge function

  18. Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

    Directory of Open Access Journals (Sweden)

    Gulfem Ergun

    2011-06-01

    Full Text Available OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED light-curing units (LCUs have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50% of the manufacturer's recommended exposure time and 40 s (100% exposure time. After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4 per well and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples followed by Rely X Unicem and Rely X ARC (90.81%, 88.90%, and 83.11%, respectively. For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively. CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical

  19. Implementation and Test of a LED-Based Lamp for a Lighthouse

    Directory of Open Access Journals (Sweden)

    Luca Mercatelli

    2014-01-01

    Full Text Available A novel sustainable source was developed for an existing Italian lighthouse, exploiting the light emitting diode (LED technology and the norms evolution. The research work started with the optical design of the device, while this work concerns the realization, installation, and test of the new LED lamp. The lamp recombines multiple separated LEDs, realizing a quasipunctual localized source. After installation in the lighthouse, specific photometric tests verified that the proposed power-saving source satisfied the illumination requirements of the marine signaling norms. The advantages of the LED-based lamp are reduced energy consumption, enhanced efficiency, longer life, decreased faults, slower aging, and lower maintenance costs. The obtained LED signalling device is more durable and reliable. In the future the application of these power-saving long-life sources could be extended to other maritime signaling devices or to other traffic signs.

  20. [Study on the safety of blue light leak of LED].

    Science.gov (United States)

    Shen, Chong-Yu; Xu, Zheng; Zhao, Su-Ling; Huang, Qing-Yu

    2014-02-01

    In this paper, the blue light properties of LED illumination devices have been investigated. Against the status quo of China's LED lighting, we measured the spectrum component of LED lamps and analyzed the photobiological safety under the current domestic and international standards GB/T 20145-2006/CIE S009/E: 2002 and IEC62471: 2006 standards as well as CTL-0744_2009-laser resolution, which provides the reference to the manufacture of LED lighting lamps as well as related safety standards and laws. If the radiance intensity of blue light in LED is lower than 100 W x m(-2) x Sr(-1), there is no harm to human eyes. LEDs will not cause harm to human eyes under normal use, but we should pay attention to the protection of special populations (children), and make sure that they avoid looking at a light source for a long time. The research has found that the blue-rich lamps can affect the human rule of work and rest, and therefore, the LED lamps with color temperature below 4 000 K and color rendering index of 80 are suitable for indoor use. At the same time, the lamps with different parameters should be selected according to the different distances.