WorldWideScience

Sample records for directional distribution

  1. Directional reflectance factor distributions of a cotton row crop

    Science.gov (United States)

    Kimes, D. S.; Newcomb, W. W.; Schutt, J. B.; Pinter, P. J., Jr.; Jackson, R. D.

    1984-01-01

    The directional reflectance factor distribution spanning the entire exitance hemisphere was measured for a cotton row crop (Gossypium barbadense L.) with 39 percent ground cover. Spectral directional radiances were taken in NOAA satellite 7 AVHRR bands 1 and 2 using a three-band radiometer with restricted 12 deg full angle field of view at half peak power points. Polar co-ordinate system plots of directional reflectance factor distributions and three-dimensional computer graphic plots of scattered flux were used to study the dynamics of the directional reflectance factor distribution as a function of spectral band, geometric structure of the scene, solar zenith and azimuth angles, and optical properties of the leaves and soil. The factor distribution of the incomplete row crops was highly polymodal relative to that for complete vegetation canopies. Besides the enhanced reflectance for the antisolar point, a reflectance minimum was observed towards the forwardscatter direction in the principle plane of the sun. Knowledge of the mechanics of the observed dynamics of the data may be used to provide rigorous validation for two- or three-dimensional radiative transfer models, and is important in interpreting aircraft and satellite data where the solar angle varies widely.

  2. Optimized velocity distributions for direct dark matter detection

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, Alejandro; Rappelt, Andreas, E-mail: ibarra@tum.de, E-mail: andreas.rappelt@tum.de [Physik-Department T30d, Technische Universität München, James-Franck-Straße, 85748 Garching (Germany)

    2017-08-01

    We present a method to calculate, without making assumptions about the local dark matter velocity distribution, the maximal and minimal number of signal events in a direct detection experiment given a set of constraints from other direct detection experiments and/or neutrino telescopes. The method also allows to determine the velocity distribution that optimizes the signal rates. We illustrate our method with three concrete applications: i) to derive a halo-independent upper limit on the cross section from a set of null results, ii) to confront in a halo-independent way a detection claim to a set of null results and iii) to assess, in a halo-independent manner, the prospects for detection in a future experiment given a set of current null results.

  3. Directed networks' different link formation mechanisms causing degree distribution distinction

    Science.gov (United States)

    Behfar, Stefan Kambiz; Turkina, Ekaterina; Cohendet, Patrick; Burger-Helmchen, Thierry

    2016-11-01

    Within undirected networks, scientists have shown much interest in presenting power-law features. For instance, Barabási and Albert (1999) claimed that a common property of many large networks is that vertex connectivity follows scale-free power-law distribution, and in another study Barabási et al. (2002) showed power law evolution in the social network of scientific collaboration. At the same time, Jiang et al. (2011) discussed deviation from power-law distribution; others indicated that size effect (Bagrow et al., 2008), information filtering mechanism (Mossa et al., 2002), and birth and death process (Shi et al., 2005) could account for this deviation. Within directed networks, many authors have considered that outlinks follow a similar mechanism of creation as inlinks' (Faloutsos et al., 1999; Krapivsky et al., 2001; Tanimoto, 2009) with link creation rate being the linear function of node degree, resulting in a power-law shape for both indegree and outdegree distribution. Some other authors have made an assumption that directed networks, such as scientific collaboration or citation, behave as undirected, resulting in a power-law degree distribution accordingly (Barabási et al., 2002). At the same time, we claim (1) Outlinks feature different degree distributions than inlinks; where different link formation mechanisms cause the distribution distinctions, (2) in/outdegree distribution distinction holds for different levels of system decomposition; therefore this distribution distinction is a property of directed networks. First, we emphasize in/outlink formation mechanisms as causal factors for distinction between indegree and outdegree distributions (where this distinction has already been noticed in Barker et al. (2010) and Baxter et al. (2006)) within a sample network of OSS projects as well as Java software corpus as a network. Second, we analyze whether this distribution distinction holds for different levels of system decomposition: open

  4. Implementing the EcoDesign Directive in distribution transformers: First impacts review

    Directory of Open Access Journals (Sweden)

    Constantinos Charalampopoulos

    2017-01-01

    Full Text Available Since the commission of the Ecodesign Directive 2005/32/EC and the review of the Directive in 2009, there has been radical change on a multitude of aspects across the grid of electrical products. Because of their high volume sales, significant environmental impact and high potential for improvement, distribution transformers were set as a priority for the Ecodesign Working Period 2009–2011. As of July 2015, the requirements of the Directive affect every unit placed into market. This study addresses the impact that the Ecodesign Directive had on the distribution transformer industry financially, environmentally, and technologically. Data has been collected from various authoritative sources in order to give an inclusive picture of the current situation, and how it may improve by the measures presented. We need to ascertain both the importance of the existing difficulties and the validity of the actions and regulations in effect so far. The purpose of this paper will be considered fulfilled if the reader can clearly understand the current state of the distribution transformer industry, the problems that the Ecodesign Directive attempts to overcome, the methods of solving said problems, and the effects that those solutions can have in the near future.

  5. Directional statistics-based reflectance model for isotropic bidirectional reflectance distribution functions.

    Science.gov (United States)

    Nishino, Ko; Lombardi, Stephen

    2011-01-01

    We introduce a novel parametric bidirectional reflectance distribution function (BRDF) model that can accurately encode a wide variety of real-world isotropic BRDFs with a small number of parameters. The key observation we make is that a BRDF may be viewed as a statistical distribution on a unit hemisphere. We derive a novel directional statistics distribution, which we refer to as the hemispherical exponential power distribution, and model real-world isotropic BRDFs as mixtures of it. We derive a canonical probabilistic method for estimating the parameters, including the number of components, of this novel directional statistics BRDF model. We show that the model captures the full spectrum of real-world isotropic BRDFs with high accuracy, but a small footprint. We also demonstrate the advantages of the novel BRDF model by showing its use for reflection component separation and for exploring the space of isotropic BRDFs.

  6. Dijet angular distributions in direct and resolved photoproduction at HERA

    International Nuclear Information System (INIS)

    Derrick, M.; Krakauer, D.; Magill, S.

    1996-05-01

    Jet photoproduction, where the two highest transverse energy (E T jet ) jets have E T jet above 6 GeV and a jet-jet invariant mass above 23 GeV, has been studied with the ZEUS detector at the HERA ep collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess. (orig.)

  7. Distributed Optimization of Multi Beam Directional Communication Networks

    Science.gov (United States)

    2017-06-30

    Distributed Optimization of Multi-Beam Directional Communication Networks Theodoros Tsiligkaridis MIT Lincoln Laboratory Lexington, MA 02141, USA...based routing. I. INTRODUCTION Missions where multiple communication goals are of in- terest are becoming more prevalent in military applications...Multilayer communications may occur within a coalition; for example, a team consisting of ground vehicles and an airborne set of assets may desire to

  8. DISTRIBUTED CONTROL ARCHITECTURE OF AN OMNI-DIRECTIONAL AUTONOMOUS GUIDED VEHICLE

    Directory of Open Access Journals (Sweden)

    N.S. Tlale

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Omni-directionality is the ability of a mobile robot to move instantaneously in any direction. This paper describes the wheel and controller designs of a Mecanumwheeled, autonomous guided vehicle (AGV for reconfigurable manufacturing systems. Mecanum wheels use slip developed between rollers and surface, surface and ground, to achieve omni-directionality. An advantage of omni-directional robotic platforms is that they are capable of performing tasks in congested environments such as those found in factory workshops, narrow aisles, warehouses, etc. Controller Area Network (CAN is implemented as a distributed controller to control motion and navigation tasks of the developed robot. The design of the distributed controller is described and its performance analyzed. This increases the reliability and functionality of the mobile robot.

    AFRIKAANSE OPSOMMING: Die artikel beskryf wiel - en beheerontwerpe van ‘n veelrigting mobiele robot. Die robot is ‘n selfstandigbeheerde voertuig vir gebruik by vervaardigingstelsels met veranderbare konfigurasie. Die ontwerp van die robot en bypassende beheerstelsel word beskryf en ontleed teen die agterground van bewegings – en navigeertake. Die betroubaarheid en funksionering van die sisteem word beoordeel.

  9. Characterisation of neutron fields: challenges in assessing the directional distribution

    International Nuclear Information System (INIS)

    Cauwels, Vanessa; Vanhavere, Filip; Reginatto, Marcel

    2014-01-01

    The SCK.CEN has carried out neutron field characterisation campaigns at several nuclear reactors. The main goal of these measurement campaigns was to evaluate the performance of different neutron personal dosemeters. To be able to evaluate the performance of neutron personal dosemeters in terms of H p (10), knowledge of the directional distribution is indispensable. This distribution was estimated by placing several personal dosemeters on all six sides of a slab phantom. The interpretation and conversion of this information into a reliable value for H p (10) requires great care. The data were analysed using three methods. In the first approach, a linear interpolation was performed on three perpendicular axes. In the other two approaches, an icosahedron was used to model the angle of incidence of the neutrons and a linear interpolation or a Bayesian analysis was performed. This study describes the limitations and advantages of each of these methods and provides recommendations for their use to estimate the personal dose equivalent H p (10) for neutron dosimetry. Neutron personal dosimetry is complicated by the fact that the neutron dose quantity H p (10) is strongly energy and angular dependent. Instead of simply assuming that the fluence is unidirectional or that the fluence is isotropic, an attempt was made to estimate the directional distribution of the neutron field using a relatively simple measurement procedure. A number of active and passive personal dosemeters were placed on the six faces of a slab phantom and the results were analysed via different algorithms to obtain partial fluences in several directions of incidence. The results from all calculations in this study show the importance of introducing information about the directional distribution of the neutron fluence for the estimation of the personal dose equivalent H p (10). The difference between H p (10) dose estimates carried out using a unidirectional or an isotropic distribution can be of up

  10. Directional short-time Fourier transform of distributions

    Directory of Open Access Journals (Sweden)

    Katerina Hadzi-Velkova Saneva

    2016-04-01

    Full Text Available Abstract In this paper we consider the directional short-time Fourier transform (DSTFT that was introduced and investigated in (Giv in J. Math. Anal. Appl. 399:100-107, 2013. We analyze the DSTFT and its transpose on test function spaces S ( R n $\\mathcal {S}(\\mathbb {R}^{n}$ and S ( Y 2 n $\\mathcal {S}(\\mathbb {Y}^{2n}$ , respectively, and prove the continuity theorems on these spaces. Then the obtained results are used to extend the DSTFT to spaces of distributions.

  11. Widespread ground motion distribution caused by rupture directivity during the 2015 Gorkha, Nepal earthquake

    Science.gov (United States)

    Koketsu, Kazuki; Miyake, Hiroe; Guo, Yujia; Kobayashi, Hiroaki; Masuda, Tetsu; Davuluri, Srinagesh; Bhattarai, Mukunda; Adhikari, Lok Bijaya; Sapkota, Soma Nath

    2016-06-01

    The ground motion and damage caused by the 2015 Gorkha, Nepal earthquake can be characterized by their widespread distributions to the east. Evidence from strong ground motions, regional acceleration duration, and teleseismic waveforms indicate that rupture directivity contributed significantly to these distributions. This phenomenon has been thought to occur only if a strike-slip or dip-slip rupture propagates to a site in the along-strike or updip direction, respectively. However, even though the earthquake was a dip-slip faulting event and its source fault strike was nearly eastward, evidence for rupture directivity is found in the eastward direction. Here, we explore the reasons for this apparent inconsistency by performing a joint source inversion of seismic and geodetic datasets, and conducting ground motion simulations. The results indicate that the earthquake occurred on the underthrusting Indian lithosphere, with a low dip angle, and that the fault rupture propagated in the along-strike direction at a velocity just slightly below the S-wave velocity. This low dip angle and fast rupture velocity produced rupture directivity in the along-strike direction, which caused widespread ground motion distribution and significant damage extending far eastwards, from central Nepal to Mount Everest.

  12. Fitting a mixture of von Mises distributions in order to model data on wind direction in Peninsular Malaysia

    International Nuclear Information System (INIS)

    Masseran, N.; Razali, A.M.; Ibrahim, K.; Latif, M.T.

    2013-01-01

    Highlights: • We suggest a simple way for wind direction modeling using the mixture of von Mises distribution. • We determine the most suitable probability model for wind direction regime in Malaysia. • We provide the circular density plots to show the most prominent directions of wind blows. - Abstract: A statistical distribution for describing wind direction provides information about the wind regime at a particular location. In addition, this information complements knowledge of wind speed, which allows researchers to draw some conclusions about the energy potential of wind and aids the development of efficient wind energy generation. This study focuses on modeling the frequency distribution of wind direction, including some characteristics of wind regime that cannot be represented by a unimodal distribution. To identify the most suitable model, a finite mixture of von Mises distributions were fitted to the average hourly wind direction data for nine wind stations located in Peninsular Malaysia. The data used were from the years 2000 to 2009. The suitability of each mixture distribution was judged based on the R 2 coefficient and the histogram plot with a density line. The results showed that the finite mixture of the von Mises distribution with H number of components was the best distribution to describe the wind direction distributions in Malaysia. In addition, the circular density plots of the suitable model clearly showed the most prominent directions of wind blows than the other directions

  13. Forecasting the Rupture Directivity of Large Earthquakes: Centroid Bias of the Conditional Hypocenter Distribution

    Science.gov (United States)

    Donovan, J.; Jordan, T. H.

    2012-12-01

    Forecasting the rupture directivity of large earthquakes is an important problem in probabilistic seismic hazard analysis (PSHA), because directivity is known to strongly influence ground motions. We describe how rupture directivity can be forecast in terms of the "conditional hypocenter distribution" or CHD, defined to be the probability distribution of a hypocenter given the spatial distribution of moment release (fault slip). The simplest CHD is a uniform distribution, in which the hypocenter probability density equals the moment-release probability density. For rupture models in which the rupture velocity and rise time depend only on the local slip, the CHD completely specifies the distribution of the directivity parameter D, defined in terms of the degree-two polynomial moments of the source space-time function. This parameter, which is zero for a bilateral rupture and unity for a unilateral rupture, can be estimated from finite-source models or by the direct inversion of seismograms (McGuire et al., 2002). We compile D-values from published studies of 65 large earthquakes and show that these data are statistically inconsistent with the uniform CHD advocated by McGuire et al. (2002). Instead, the data indicate a "centroid biased" CHD, in which the expected distance between the hypocenter and the hypocentroid is less than that of a uniform CHD. In other words, the observed directivities appear to be closer to bilateral than predicted by this simple model. We discuss the implications of these results for rupture dynamics and fault-zone heterogeneities. We also explore their PSHA implications by modifying the CyberShake simulation-based hazard model for the Los Angeles region, which assumed a uniform CHD (Graves et al., 2011).

  14. Anisotropic dark matter distribution functions and impact on WIMP direct detection

    International Nuclear Information System (INIS)

    Bozorgnia, Nassim; Schwetz, Thomas; Catena, Riccardo

    2013-01-01

    Dark matter N-body simulations suggest that the velocity distribution of dark matter is anisotropic. In this work we employ a mass model for the Milky Way whose parameters are determined from a fit to kinematical data. Then we adopt an ansatz for the dark matter phase space distribution which allows to construct self-consistent halo models which feature a degree of anisotropy as a function of the radius such as suggested by the simulations. The resulting velocity distributions are then used for an analysis of current data from dark matter direct detection experiments. We find that velocity distributions which are radially biased at large galactocentric distances (up to the virial radius) lead to an increased high velocity tail of the local dark matter distribution. This affects the interpretation of data from direct detection experiments, especially for dark matter masses around 10 GeV, since in this region the high velocity tail is sampled. We find that the allowed regions in the dark matter mass-cross section plane as indicated by possible hints for a dark matter signal reported by several experiments as well as conflicting exclusion limits from other experiments shift in a similar way when the halo model is varied. Hence, it is not possible to improve the consistency of the data by referring to anisotropic halo models of the type considered in this work

  15. DISTRIBUTION ASPECTS OF THE DIRECT PAYMENTS BETWEEN EU MEMBER STATES

    Directory of Open Access Journals (Sweden)

    Gina FINTINERU

    2012-01-01

    Full Text Available EC proposals concerning CAP reform for 2014-2020 try to cope both with the wide variety of agricultural systems and economic structures of the 27 EU MS but also with current global challenges that agriculture has to face: food security and poverty reduction, climate changes or biodiversity loss. This article aims to analyse the proposed measures consistency with the current situation of Romanian agriculture. Distribution aspects of the direct payments between Member States are concerned. The data are originated in FADN and Eurostat statistics, and a non parametric approach is used in order to better understand the correlation between the direct payments proposed for 2014 -2020 and some socio economic criteria.The paper provides a brief analysis of the existing research concerning the distributional aspects (studies and statistics and contributes to the debate by examining if the proposed redistribution is a consistent and coherent answer to the future challenges the agriculture has to meet in the future and to the targeted equity criteria.

  16. The temporal distribution of directional gradients under selection for an optimum.

    Science.gov (United States)

    Chevin, Luis-Miguel; Haller, Benjamin C

    2014-12-01

    Temporal variation in phenotypic selection is often attributed to environmental change causing movements of the adaptive surface relating traits to fitness, but this connection is rarely established empirically. Fluctuating phenotypic selection can be measured by the variance and autocorrelation of directional selection gradients through time. However, the dynamics of these gradients depend not only on environmental changes altering the fitness surface, but also on evolution of the phenotypic distribution. Therefore, it is unclear to what extent variability in selection gradients can inform us about the underlying drivers of their fluctuations. To investigate this question, we derive the temporal distribution of directional gradients under selection for a phenotypic optimum that is either constant or fluctuates randomly in various ways in a finite population. Our analytical results, combined with population- and individual-based simulations, show that although some characteristic patterns can be distinguished, very different types of change in the optimum (including a constant optimum) can generate similar temporal distributions of selection gradients, making it difficult to infer the processes underlying apparent fluctuating selection. Analyzing changes in phenotype distributions together with changes in selection gradients should prove more useful for inferring the mechanisms underlying estimated fluctuating selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  17. Determination of the crystallite orientation distribution from direct pole figures

    International Nuclear Information System (INIS)

    Araujo Gomes, P.A.M. de.

    1977-01-01

    A method is described which allows to calculate the crystallite orientation distribution in polycrystalline material, from direct pole figures data of its crystallographic planes (Roe's Method). The programme was applied to (1010), (0002), (1011) and (1120) complete pole figures data for a commercial, thin sheet Zircaloy-4 tubing specimen. A semi-automatic Rigaku-Denki texture goniometer, which scans the reciprocal lattice sphere pointwise outputting the data in a punched tape, was used to obtain the pole figures. This is consistent with the results obtained through direct conclusion from the pole figures. (author)

  18. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    OpenAIRE

    Jakub Ehrenberger; Jan Švec

    2017-01-01

    This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordinat...

  19. The law of distribution of light beam direction fluctuations in telescopes. [normal density functions

    Science.gov (United States)

    Divinskiy, M. L.; Kolchinskiy, I. G.

    1974-01-01

    The distribution of deviations from mean star trail directions was studied on the basis of 105 star trails. It was found that about 93% of the trails yield a distribution in agreement with the normal law. About 4% of the star trails agree with the Charlier distribution.

  20. Directionality of recent bird distribution shifts and climate change in Great Britain.

    Science.gov (United States)

    Gillings, Simon; Balmer, Dawn E; Fuller, Robert J

    2015-06-01

    There is good evidence that species' distributions are shifting poleward in response to climate change and wide interest in the magnitude of such responses for scientific and conservation purposes. It has been suggested from the directions of climatic changes that species' distribution shifts may not be simply poleward, but this has been rarely tested with observed data. Here, we apply a novel approach to measuring range shifts on axes ranging through 360°, to recent data on the distributions of 122 species of British breeding birds during 1988-1991 and 2008-2011. Although previously documented poleward range shifts have continued, with an average 13.5 km shift northward, our analysis indicates this is an underestimate because it ignores common and larger shifts that occurred along axes oriented to the north-west and north-east. Trailing edges contracted from a broad range of southerly directions. Importantly, these results are derived from systematically collected data so confounding observer-effort biases can be discounted. Analyses of climate for the same period show that whilst temperature trends should drive species along a north-north-westerly trajectory, directional responses to precipitation will depend on both the time of year that is important for determining a species' distribution, and the location of the range margin. Directions of species' range centroid shift were not correlated with spatial trends in any single climate variable. We conclude that range shifts of British birds are multidirectional, individualistic and probably determined by species-specific interactions of multiple climate factors. Climate change is predicted to lead to changes in community composition through variation in the rates that species' ranges shift; our results suggest communities could change further owing to constituent species shifting along different trajectories. We recommend more studies consider directionality in climate and range dynamics to produce more

  1. Design wave estimation considering directional distribution of waves

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Deo, M.C

    .elsevier.com/locate/oceaneng Technical Note Design wave estimation considering directional distribution of waves V. Sanil Kumar a,C3 , M.C. Deo b a OceanEngineeringDivision,NationalInstituteofOceanography,Donapaula,Goa-403004,India b Civil... of Physical Oceanography Norway, Report method for the routine 18, 1020–1034. ocean waves. Division of No. UR-80-09, 187 p. analysis of pitch and roll Conference on Coastal Engineering, 1. ASCE, Taiwan, pp. 136–149. Deo, M.C., Burrows, R., 1986. Extreme wave...

  2. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    OpenAIRE

    Ju Feng; Wen Zhong Shen

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distributions of wind speed and wind direction, which is based on the parameters of sector-wise Weibull distributions and interpolations between direction sectors. It is applied to the wind measurement data a...

  3. In situ diagnostic of water distribution in thickness direction of MEA by neutron imaging. Focused on characteristics of water distribution in gas diffusion layer

    International Nuclear Information System (INIS)

    Tasaki, Yutaka; Ichikawa, Yasushi; Kobo, Norio; Shinohara, Kazuhiko; Boillat, Pierre; Kramer, Denis; Scherer, Gunther G.; Lehmann, Eberhard H.

    2008-01-01

    The mass transfer characteristics of gas diffusion layer (GDL) are closely related to cell performance in PEFC. In this study, In situ diagnostic of water distribution in thickness direction of MEA by Neutron Imaging has been carried out for three MEAs with different GDLs on cathode side as well as I-V characteristics. It was confirmed that this method is useful for analyzing water distribution in thickness direction of MEA. The relationship between I-V characteristics and liquid water distribution has been studied. (author)

  4. Inverter power module with distributed support for direct substrate cooling

    Science.gov (United States)

    Miller, David Harold [San Pedro, CA; Korich, Mark D [Chino Hills, CA; Ward, Terence G [Redondo Beach, CA; Mann, Brooks S [Redondo Beach, CA

    2012-08-21

    Systems and/or methods are provided for an inverter power module with distributed support for direct substrate cooling. An inverter module comprises a power electronic substrate. A first support frame is adapted to house the power electronic substrate and has a first region adapted to allow direct cooling of the power electronic substrate. A gasket is interposed between the power electronic substrate and the first support frame. The gasket is configured to provide a seal between the first region and the power electronic substrate. A second support frame is adapted to house the power electronic substrate and joined to the first support frame to form the seal.

  5. Prediction of sound transmission loss through multilayered panels by using Gaussian distribution of directional incident energy

    Science.gov (United States)

    Kang; Ih; Kim; Kim

    2000-03-01

    In this study, a new prediction method is suggested for sound transmission loss (STL) of multilayered panels of infinite extent. Conventional methods such as random or field incidence approach often given significant discrepancies in predicting STL of multilayered panels when compared with the experiments. In this paper, appropriate directional distributions of incident energy to predict the STL of multilayered panels are proposed. In order to find a weighting function to represent the directional distribution of incident energy on the wall in a reverberation chamber, numerical simulations by using a ray-tracing technique are carried out. Simulation results reveal that the directional distribution can be approximately expressed by the Gaussian distribution function in terms of the angle of incidence. The Gaussian function is applied to predict the STL of various multilayered panel configurations as well as single panels. The compared results between the measurement and the prediction show good agreements, which validate the proposed Gaussian function approach.

  6. Bi-directional reflectance distribution function of a tungsten block for ITER divertor

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Ogawa, Hiroaki; Sugie, Tatsuo; Kusama, Yoshinori

    2012-02-01

    In order to investigate reflection properties on plasma-facing material in ITER, the bi-directional reflectance distribution function (BRDF) of a tungsten block sample has been measured. On the machining surface of the block, one-directional machining lines are engraved. Two laser diodes λ652 nm and λ473 nm were used to simulate H α and H β emissions, respectively. The reflected light is affected by the machining surface. The reflected light traces an arc when the incident light is injected in the parallel direction to the engraved line. On the other hand the reflected light traces a line shape when the incident light is injected in the perpendicular direction to the engraved lines. Ray tracing simulation qualitatively explains the experimental results. (author)

  7. Information Modeling for Direct Control of Distributed Energy Resources

    DEFF Research Database (Denmark)

    Biegel, Benjamin; Andersen, Palle; Stoustrup, Jakob

    2013-01-01

    We present an architecture for an unbundled liberalized electricity market system where a virtual power plant (VPP) is able to control a number of distributed energy resources (DERs) directly through a two-way communication link. The aggregator who operates the VPP utilizes the accumulated...... a desired accumulated response. In this paper, we design such an information model based on the markets that the aggregator participates in and based on the flexibility characteristics of the remote controlled DERs. The information model is constructed in a modular manner making the interface suitable...

  8. Distributions of Mutational Effects and the Estimation of Directional Selection in Divergent Lineages of Arabidopsis thaliana.

    Science.gov (United States)

    Park, Briton; Rutter, Matthew T; Fenster, Charles B; Symonds, V Vaughan; Ungerer, Mark C; Townsend, Jeffrey P

    2017-08-01

    Mutations are crucial to evolution, providing the ultimate source of variation on which natural selection acts. Due to their key role, the distribution of mutational effects on quantitative traits is a key component to any inference regarding historical selection on phenotypic traits. In this paper, we expand on a previously developed test for selection that could be conducted assuming a Gaussian mutation effect distribution by developing approaches to also incorporate any of a family of heavy-tailed Laplace distributions of mutational effects. We apply the test to detect directional natural selection on five traits along the divergence of Columbia and Landsberg lineages of Arabidopsis thaliana , constituting the first test for natural selection in any organism using quantitative trait locus and mutation accumulation data to quantify the intensity of directional selection on a phenotypic trait. We demonstrate that the results of the test for selection can depend on the mutation effect distribution specified. Using the distributions exhibiting the best fit to mutation accumulation data, we infer that natural directional selection caused divergence in the rosette diameter and trichome density traits of the Columbia and Landsberg lineages. Copyright © 2017 by the Genetics Society of America.

  9. The influence of the directional energy distribution on the nonlinear dispersion relation in a random gravity wave field

    Science.gov (United States)

    Huang, N. E.; Tung, C.-C.

    1977-01-01

    The influence of the directional distribution of wave energy on the dispersion relation is calculated numerically using various directional wave spectrum models. The results indicate that the dispersion relation varies both as a function of the directional energy distribution and the direction of propagation of the wave component under consideration. Furthermore, both the mean deviation and the random scatter from the linear approximation increase as the energy spreading decreases. Limited observational data are compared with the theoretical results. The agreement is favorable.

  10. Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions

    Energy Technology Data Exchange (ETDEWEB)

    Vanier P. e.; Dioszegi, I.; Salwen, C.; Forman, L.

    2009-10-25

    We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.

  11. Reconstruction of the electron momentum distribution from a set of directional Compton profiles

    International Nuclear Information System (INIS)

    Hansen, N.K.

    1980-12-01

    A method is described in which the 3-dimensional one-electron momentum density distribution is obtained from a series of directional Compton profiles measured on single crystals; a directional Compton profile being the projection of the momentum density onto a line through the origin. The procedure consists of 1-dimensional Fourier transformations of the individual profiles. The Fourier transformed Compton profiles are fitted by a finite expansion in lattice harmonic functions, and the momentum density is finally obtained by a 3-dimensional Fourier transform. The effect of statistical errors are derived both for the momentum density and its Fourier transform. The problem of how to carry out the measurements in an optimal way has been approached and suggestions made. A computer program for calculation of momentum density and error distributions have been listed in an appendix. (orig.)

  12. Measurement of proton momentum distributions using a direct geometry instrument

    International Nuclear Information System (INIS)

    Senesi, R; Andreani, C; Kolesnikov, A I

    2014-01-01

    We report the results of inelastic neutron scattering measurements on bulk water and ice using the direct geometry SEQUOIA chopper spectrometer at the Spallation Neutron Source (USA), with incident energy E i = 6 eV. In this set up the measurements allow to access the Deep Inelastic Neutron Scattering regime. The scattering is centred at the proton recoil energy given by the impulse approximation, and the shape of the recoil peak conveys information on the proton momentum distribution in the system. The comparison with the performance of inverse geometry instruments, such as VESUVIO at the ISIS source (UK), shows that complementary information can be accessed by the use of direct and inverse geometry instruments. Analysis of the neutron Compton profiles shows that the proton kinetic energy in ice at 271 K is larger than in room temperature liquid water, in agreement with previous measurements on VESUVIO

  13. Energy efficient direct current distribution in commercially used buildings with smart power link to the AC distribution grid; Energieeffiziente Gleichstromverteilung in kommerziell genutzten Gebaeuden mit intelligenter Kopplung zum Niederspannungsnetz

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Roland [Siemens AG, Erlangen (Germany); Boeke, Ulrich [Philips Group Innovation-Research, Eindhoven (Netherlands); Maurer, Wilhelm [Infineon Technologies AG, Neubiberg (Germany); Zeltner, Stefan [Fraunhofer-Inst. fuer Integrierte Systeme und Bauelementetechnologie (IISB), Erlangen (Germany)

    2012-07-01

    The joint undertaking ''Direct Current Components and Grid'' (DCC+G) takes on the strategic challenge to reduce energy consumption and thus the reduction of CO{sub 2} emission caused by commercially used buildings through research in the fields of Direct Current distribution at a voltage level of {+-} 380 V. The major energy consumers in commercially used buildings, ready for the ''net-zero-energy'' goal of the European Union, are heat pumps for heating, ventilation systems, air conditioning units, cooling units (HVAC), lighting systems and information technology. All these components and subsystems have in common, that the most efficient versions would benefit from a direct current supply. Additionally the local producers of electric energy like photovoltaic systems usually generate DC-current. A Direct Current distribution grid within buildings would avoid the repeating conversion from DC and AC an vice versa and therefore reduce conversion losses. Important components of a direct current distribution grid are central, smart, high efficient, bidirectional rectifiers replacing the large number of small, less efficient rectifiers used today. Such large central rectifiers units could additionally be used to actively improve the power quality of the smart local AC distribution grid. One major part of the described activities is to show energy savings of about 5 % of electrical energy with a 2-phase direct current distribution grid using a voltage level of {+-} 380 V. (orig.)

  14. From neutron Compton profiles to momentum distribution: Assessment of direct numerical determination

    International Nuclear Information System (INIS)

    Senesi, R.; Flammini, D.; Romanelli, G.; Andreani, C.

    2013-01-01

    Inelastic neutron scattering at high momentum transfers, in the neutron Compton scattering regime, provides an access to the neutron Compton profiles, the analogous of Compton profiles in X-ray scattering. The line shape analysis of the neutron Compton profiles is usually carried out making use of multiparametric nonlinear fitting, garnering detailed information about the momentum distribution of the target atoms. This paper presents the proposal to directly determine numerically the momentum distribution from the profiles, thus eliminating the possible instabilities present in multiparametric fitting. A comparison with Monte Carlo simulations and with previous measurements on polycrystalline ice provides quantitative assessments of the proposed method

  15. Cash social transfers, direct taxes, and income distribution in late socialism

    OpenAIRE

    Milanovic, Branko

    1993-01-01

    The author analyzes the impact of direct taxes and cash social transfers on income distribution in Bulgaria, Czechoslovakia, Hungary, Poland and Yugoslavia in the years before the collapse of communism. He contrasts the results for socialist and market economies. Cash social transfers accounted for about a fifth of gross income, a proportion comparable with that in developed welfare economies. Generally, cash transfers were unrelated to income in socialist countries, in marked contrast with m...

  16. Distributed Cooperative Optimal Control for Multiagent Systems on Directed Graphs: An Inverse Optimal Approach.

    Science.gov (United States)

    Zhang, Huaguang; Feng, Tao; Yang, Guang-Hong; Liang, Hongjing

    2015-07-01

    In this paper, the inverse optimal approach is employed to design distributed consensus protocols that guarantee consensus and global optimality with respect to some quadratic performance indexes for identical linear systems on a directed graph. The inverse optimal theory is developed by introducing the notion of partial stability. As a result, the necessary and sufficient conditions for inverse optimality are proposed. By means of the developed inverse optimal theory, the necessary and sufficient conditions are established for globally optimal cooperative control problems on directed graphs. Basic optimal cooperative design procedures are given based on asymptotic properties of the resulting optimal distributed consensus protocols, and the multiagent systems can reach desired consensus performance (convergence rate and damping rate) asymptotically. Finally, two examples are given to illustrate the effectiveness of the proposed methods.

  17. Moving target tracking through distributed clustering in directional sensor networks.

    Science.gov (United States)

    Enayet, Asma; Razzaque, Md Abdur; Hassan, Mohammad Mehedi; Almogren, Ahmad; Alamri, Atif

    2014-12-18

    The problem of moving target tracking in directional sensor networks (DSNs) introduces new research challenges, including optimal selection of sensing and communication sectors of the directional sensor nodes, determination of the precise location of the target and an energy-efficient data collection mechanism. Existing solutions allow individual sensor nodes to detect the target's location through collaboration among neighboring nodes, where most of the sensors are activated and communicate with the sink. Therefore, they incur much overhead, loss of energy and reduced target tracking accuracy. In this paper, we have proposed a clustering algorithm, where distributed cluster heads coordinate their member nodes in optimizing the active sensing and communication directions of the nodes, precisely determining the target location by aggregating reported sensing data from multiple nodes and transferring the resultant location information to the sink. Thus, the proposed target tracking mechanism minimizes the sensing redundancy and maximizes the number of sleeping nodes in the network. We have also investigated the dynamic approach of activating sleeping nodes on-demand so that the moving target tracking accuracy can be enhanced while maximizing the network lifetime. We have carried out our extensive simulations in ns-3, and the results show that the proposed mechanism achieves higher performance compared to the state-of-the-art works.

  18. Moving Target Tracking through Distributed Clustering in Directional Sensor Networks

    Directory of Open Access Journals (Sweden)

    Asma Enayet

    2014-12-01

    Full Text Available The problem of moving target tracking in directional sensor networks (DSNs introduces new research challenges, including optimal selection of sensing and communication sectors of the directional sensor nodes, determination of the precise location of the target and an energy-efficient data collection mechanism. Existing solutions allow individual sensor nodes to detect the target’s location through collaboration among neighboring nodes, where most of the sensors are activated and communicate with the sink. Therefore, they incur much overhead, loss of energy and reduced target tracking accuracy. In this paper, we have proposed a clustering algorithm, where distributed cluster heads coordinate their member nodes in optimizing the active sensing and communication directions of the nodes, precisely determining the target location by aggregating reported sensing data from multiple nodes and transferring the resultant location information to the sink. Thus, the proposed target tracking mechanism minimizes the sensing redundancy and maximizes the number of sleeping nodes in the network. We have also investigated the dynamic approach of activating sleeping nodes on-demand so that the moving target tracking accuracy can be enhanced while maximizing the network lifetime. We have carried out our extensive simulations in ns-3, and the results show that the proposed mechanism achieves higher performance compared to the state-of-the-art works.

  19. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

    Science.gov (United States)

    Wen, Cuihong; Zhang, Jing; Rebelo, Ana; Cheng, Fanyong

    2016-01-01

    Optical Music Recognition (OMR) has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM). The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM), which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs) and Neural Networks (NNs).

  20. Air conditioning system and component therefore distributing air flow from opposite directions

    Science.gov (United States)

    Obler, H. D.; Bauer, H. B. (Inventor)

    1974-01-01

    The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

  1. The Analysis of the Strength, Distribution and Direction for the EEG Phase Synchronization by Musical Stimulus

    Science.gov (United States)

    Ogawa, Yutaro; Ikeda, Akira; Kotani, Kiyoshi; Jimbo, Yasuhiko

    In this study, we propose the EEG phase synchronization analysis including not only the average strength of the synchronization but also the distribution and directions under the conditions that evoked emotion by musical stimuli. The experiment is performed with the two different musical stimuli that evoke happiness or sadness for 150 seconds. It is found that the average strength of synchronization indicates no difference between the right side and the left side of the frontal lobe during the happy stimulus, the distribution and directions indicate significant differences. Therefore, proposed analysis is useful for detecting emotional condition because it provides information that cannot be obtained only by the average strength of synchronization.

  2. Measurement of temperature distributions in large pool fires with the use of directional flame thermometers

    International Nuclear Information System (INIS)

    Koski, Jorman A.

    2000-01-01

    Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C

  3. Distributed Adaptive Finite-Time Approach for Formation-Containment Control of Networked Nonlinear Systems Under Directed Topology.

    Science.gov (United States)

    Wang, Yujuan; Song, Yongduan; Ren, Wei

    2017-07-06

    This paper presents a distributed adaptive finite-time control solution to the formation-containment problem for multiple networked systems with uncertain nonlinear dynamics and directed communication constraints. By integrating the special topology feature of the new constructed symmetrical matrix, the technical difficulty in finite-time formation-containment control arising from the asymmetrical Laplacian matrix under single-way directed communication is circumvented. Based upon fractional power feedback of the local error, an adaptive distributed control scheme is established to drive the leaders into the prespecified formation configuration in finite time. Meanwhile, a distributed adaptive control scheme, independent of the unavailable inputs of the leaders, is designed to keep the followers within a bounded distance from the moving leaders and then to make the followers enter the convex hull shaped by the formation of the leaders in finite time. The effectiveness of the proposed control scheme is confirmed by the simulation.

  4. A Directed Acyclic Graph-Large Margin Distribution Machine Model for Music Symbol Classification.

    Directory of Open Access Journals (Sweden)

    Cuihong Wen

    Full Text Available Optical Music Recognition (OMR has received increasing attention in recent years. In this paper, we propose a classifier based on a new method named Directed Acyclic Graph-Large margin Distribution Machine (DAG-LDM. The DAG-LDM is an improvement of the Large margin Distribution Machine (LDM, which is a binary classifier that optimizes the margin distribution by maximizing the margin mean and minimizing the margin variance simultaneously. We modify the LDM to the DAG-LDM to solve the multi-class music symbol classification problem. Tests are conducted on more than 10000 music symbol images, obtained from handwritten and printed images of music scores. The proposed method provides superior classification capability and achieves much higher classification accuracy than the state-of-the-art algorithms such as Support Vector Machines (SVMs and Neural Networks (NNs.

  5. Wind direction/velocity and current direction/velocity data from current meter casts in a world wide distribution from 1970-12-06 to 1991-10-01 (NODC Accession 9700218)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind direction/velocity and current direction/velocity data were collected using current meter casts in a world wide distribution from December 6, 1970 to October 1,...

  6. Event-Triggered Distributed Average Consensus Over Directed Digital Networks With Limited Communication Bandwidth.

    Science.gov (United States)

    Li, Huaqing; Chen, Guo; Huang, Tingwen; Dong, Zhaoyang; Zhu, Wei; Gao, Lan

    2016-12-01

    In this paper, we consider the event-triggered distributed average-consensus of discrete-time first-order multiagent systems with limited communication data rate and general directed network topology. In the framework of digital communication network, each agent has a real-valued state but can only exchange finite-bit binary symbolic data sequence with its neighborhood agents at each time step due to the digital communication channels with energy constraints. Novel event-triggered dynamic encoder and decoder for each agent are designed, based on which a distributed control algorithm is proposed. A scheme that selects the number of channel quantization level (number of bits) at each time step is developed, under which all the quantizers in the network are never saturated. The convergence rate of consensus is explicitly characterized, which is related to the scale of network, the maximum degree of nodes, the network structure, the scaling function, the quantization interval, the initial states of agents, the control gain and the event gain. It is also found that under the designed event-triggered protocol, by selecting suitable parameters, for any directed digital network containing a spanning tree, the distributed average consensus can be always achieved with an exponential convergence rate based on merely one bit information exchange between each pair of adjacent agents at each time step. Two simulation examples are provided to illustrate the feasibility of presented protocol and the correctness of the theoretical results.

  7. Distributed coordination of heterogeneous agents using a semantic overlay network and a goal-directed graphplan planner.

    Directory of Open Access Journals (Sweden)

    António Luís Lopes

    Full Text Available In this paper, we describe a distributed coordination system that allows agents to seamlessly cooperate in problem solving by partially contributing to a problem solution and delegating the subproblems for which they do not have the required skills or knowledge to appropriate agents. The coordination mechanism relies on a dynamically built semantic overlay network that allows the agents to efficiently locate, even in very large unstructured networks, the necessary skills for a specific problem. Each agent performs partial contributions to the problem solution using a new distributed goal-directed version of the Graphplan algorithm. This new goal-directed version of the original Graphplan algorithm provides an efficient solution to the problem of "distraction", which most forward-chaining algorithms suffer from. We also discuss a set of heuristics to be used in the backward-search process of the planning algorithm in order to distribute this process amongst idle agents in an attempt to find a solution in less time. The evaluation results show that our approach is effective in building a scalable and efficient agent society capable of solving complex distributable problems.

  8. Geographical distribution of radiation risk unaccountable by direct exposure dose in hiroshima A-bomb victims

    International Nuclear Information System (INIS)

    Tonda, Tetsuji; Satoh, Kenichi; Ohani, Keiko

    2012-01-01

    Death risks due to solid cancer were estimated from region to region where the A-bomb survivors had been actually exposed, to visualize the risk distribution on the map, which resulting in risk regional difference that had been unaccountable by direct exposure dose estimation. Analysis was performed with 3 hazard models of the previous one, + direct exposed dose as a confounding factor and, further, + spatial distance from the explosion point. Subjects were 37,382 A-bomb survivors at Jan. 1, 1970 with known positional coordinate at explosion, followed until Dec. 31, 2009, whose endpoint was set by 4,371 deaths due to cancer except leukemia, cancers of thyroid and breast. Confounding factors in the previous hazard model were sex, age at the exposure, dose and shielding. With the previous model, risk distribution was observed in a concentric circular region around the hypocenter and in an additional west to northwestern suburbs. The latter risk distribution was also seen with the second model in the same region, where dose decreased with -7 powers of the distance. When adjusted with -3 powers of the distance with the third model, the actual risk distribution was found best fitted, indicating the presence of distance-dependent risk. It was suggested that the region exposed to additional dose possibly derived from fallout had been the actual black rainfall area as those regions agreed with each other. (T.T.)

  9. Fitting a circular distribution based on nonnegative trigonometric sums for wind direction in Malaysia

    Science.gov (United States)

    Masseran, Nurulkamal; Razali, Ahmad Mahir; Ibrahim, Kamarulzaman; Zaharim, Azami; Sopian, Kamaruzzaman

    2015-02-01

    Wind direction has a substantial effect on the environment and human lives. As examples, the wind direction influences the dispersion of particulate matter in the air and affects the construction of engineering structures, such as towers, bridges, and tall buildings. Therefore, a statistical analysis of the wind direction provides important information about the wind regime at a particular location. In addition, knowledge of the wind direction and wind speed can be used to derive information about the energy potential. This study investigated the characteristics of the wind regime of Mersing, Malaysia. A circular distribution based on Nonnegative Trigonometric Sums (NNTS) was fitted to a histogram of the average hourly wind direction data. The Newton-like manifold algorithm was used to estimate the parameter of each component of the NNTS model. Next, the suitability of each NNTS model was judged based on a graphical representation and Akaike's Information Criteria. The study found that the NNTS model with six or more components was able to fit the wind directional data for the Mersing station.

  10. Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing

    Science.gov (United States)

    Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A. Ping; Lu, Chao

    2016-01-01

    We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes. PMID:27999250

  11. Bi-Directional Brillouin Optical Time Domain Analyzer System for Long Range Distributed Sensing.

    Science.gov (United States)

    Guo, Nan; Wang, Liang; Wang, Jie; Jin, Chao; Tam, Hwa-Yaw; Zhang, A Ping; Lu, Chao

    2016-12-16

    We propose and experimentally demonstrate a novel scheme of bi-directional Brillouin time domain analyzer (BD-BOTDA) to extend the sensing range. By deploying two pump-probe pairs at two different wavelengths, the Brillouin frequency shift (BFS) distribution over each half of the whole fiber can be obtained with the simultaneous detection of Brillouin signals in both channels. Compared to the conventional unidirectional BOTDA system of the same sensing range, the proposed BD-BOTDA scheme enables distributed sensing with a performance level comparable to the conventional one with half of the sensing range and a spatial resolution of 2 m, while maintaining the Brillouin signal-to-noise ratio (SNR) and the BFS uncertainty. Based on this technique, we have achieved distributed temperature sensing with a measurement range of 81.9 km fiber at a spatial resolution of 2 m and BFS uncertainty of ~0.44 MHz without introducing any complicated components or schemes.

  12. Inferring processes from spatial patterns: the role of directional and non-directional forces in shaping fish larvae distribution in a freshwater lake system.

    Directory of Open Access Journals (Sweden)

    Andrea Bertolo

    Full Text Available Larval dispersal is a crucial factor for fish recruitment. For fishes with relatively small-bodied larvae, drift has the potential to play a more important role than active habitat selection in determining larval dispersal; therefore, we expect small-bodied fish larvae to be poorly associated with habitat characteristics. To test this hypothesis, we used as model yellow perch (Perca flavescens, whose larvae are among the smallest among freshwater temperate fishes. Thus, we analysed the habitat association of yellow perch larvae at multiple spatial scales in a large shallow fluvial lake by explicitly modelling directional (e.g. due to water currents and non-directional (e.g. due to aggregation spatial patterns. This allowed us to indirectly assess the relative roles of drift (directional process and potential habitat choice on larval dispersal. Our results give weak support to the drift hypothesis, whereas yellow perch show a strong habitat association at unexpectedly small sizes, when compared to other systems. We found consistent non-directional patterns in larvae distributions at both broad and medium spatial scales but only few significant directional components. The environmental variables alone (e.g. vegetation generally explained a significant and biologically relevant fraction of the variation in fish larvae distribution data. These results suggest that (i drift plays a minor role in this shallow system, (ii larvae display spatial patterns that only partially covary with environmental variables, and (iii larvae are associated to specific habitats. By suggesting that habitat association potentially includes an active choice component for yellow perch larvae, our results shed new light on the ecology of freshwater fish larvae and should help in building more realistic recruitment models.

  13. Direct measurement of the charge distribution along a biased carbon nanotube bundle using electron holography

    DEFF Research Database (Denmark)

    Beleggia, Marco; Kasama, Takeshi; Dunin-Borkowski, Rafal E.

    2011-01-01

    Nanowires and nanotubes can be examined in the transmission electron microscope under an applied bias. Here we introduce a model-independent method, which allows the charge distribution along a nanowire or nanotube to be measured directly from the Laplacian of an electron holographic phase image....

  14. Collapse transition and cyclomatic number distribution of directed lattice animals

    International Nuclear Information System (INIS)

    Lam, P.M.; Duarte, J.A.M.S.

    1987-01-01

    The authors computed the specific heat of directed lattice animals using a Monte Carlo method for various animals sizes N, with N up to 100 on the square and N up to 125 on the simple cubic lattices. The specific heat as a function of the temperature for various animal sizes exhibits peaks which seem to approach a collapse transition temperature monotonically from below with increasing N. A least square fit together with finite-size scaling then gives both the transition temperature T/sub c/ and the specific heat exponent α for these lattices. The cyclomatic number distributions for the number of animals with fixed animal size N are also calculated and these seem to obey a scaling law for large N

  15. SuperLU{_}DIST: A scalable distributed-memory sparse direct solver for unsymmetric linear systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoye S.; Demmel, James W.

    2002-03-27

    In this paper, we present the main algorithmic features in the software package SuperLU{_}DIST, a distributed-memory sparse direct solver for large sets of linear equations. We give in detail our parallelization strategies, with focus on scalability issues, and demonstrate the parallel performance and scalability on current machines. The solver is based on sparse Gaussian elimination, with an innovative static pivoting strategy proposed earlier by the authors. The main advantage of static pivoting over classical partial pivoting is that it permits a priori determination of data structures and communication pattern for sparse Gaussian elimination, which makes it more scalable on distributed memory machines. Based on this a priori knowledge, we designed highly parallel and scalable algorithms for both LU decomposition and triangular solve and we show that they are suitable for large-scale distributed memory machines.

  16. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-01-01

    The center-of-mass angular distribution of direct photon events, resulting from proton-antiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermi lab ( CDF) during the 1988-1089 experimental run, is presented. The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momentum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator.

  17. Direct Photon Center-of-Mass Angular Distributions in $p\\bar{p}$ Collisions at $\\sqrt{s}$ =1.8-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, Leslie F. [Brandeis Univ., Waltham, MA (United States)

    1992-04-01

    The center-of-mass angular distribution of direct photon events, resulting from protonantiproton collisions at a center-of-mass energy of 1.8 TeV, as measured by the Collider Detector at Fermilab ( CDF) during the 1988-1089 experimental run, is presented . The direct photon events are identified primarily through the direct photon's characteristic isolation from other particles. The main source of background is from rare fragmentation of QCD partons into single isolated neutral mesons, which decay into two or more photons. The background is removed statistically by exploitation of tile expected difference in the resulting shower profiles. The resulting angular distribution for direct photons, in the transverse momemtum range from 22 to 45 Ge V is found to agree favorably with the predictions of Quantum Cbromodynamics (QCD) for an interaction with a fermion (spin 1/2) propagator

  18. Fast computation of statistical uncertainty for spatiotemporal distributions estimated directly from dynamic cone beam SPECT projections

    International Nuclear Information System (INIS)

    Reutter, Bryan W.; Gullberg, Grant T.; Huesman, Ronald H.

    2001-01-01

    The estimation of time-activity curves and kinetic model parameters directly from projection data is potentially useful for clinical dynamic single photon emission computed tomography (SPECT) studies, particularly in those clinics that have only single-detector systems and thus are not able to perform rapid tomographic acquisitions. Because the radiopharmaceutical distribution changes while the SPECT gantry rotates, projections at different angles come from different tracer distributions. A dynamic image sequence reconstructed from the inconsistent projections acquired by a slowly rotating gantry can contain artifacts that lead to biases in kinetic parameters estimated from time-activity curves generated by overlaying regions of interest on the images. If cone beam collimators are used and the focal point of the collimators always remains in a particular transaxial plane, additional artifacts can arise in other planes reconstructed using insufficient projection samples [1]. If the projection samples truncate the patient's body, this can result in additional image artifacts. To overcome these sources of bias in conventional image based dynamic data analysis, we and others have been investigating the estimation of time-activity curves and kinetic model parameters directly from dynamic SPECT projection data by modeling the spatial and temporal distribution of the radiopharmaceutical throughout the projected field of view [2-8]. In our previous work we developed a computationally efficient method for fully four-dimensional (4-D) direct estimation of spatiotemporal distributions from dynamic SPECT projection data [5], which extended Formiconi's least squares algorithm for reconstructing temporally static distributions [9]. In addition, we studied the biases that result from modeling various orders temporal continuity and using various time samplings [5]. the present work, we address computational issues associated with evaluating the statistical uncertainty of

  19. SU-F-BRA-06: Dose Distributions for the CivaSheet Pd-103 Directional Brachytherapy Device

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, MJ [Tufts University School of Medicine, Boston, MA (United States)

    2015-06-15

    Purpose: A flexible polymer membrane (CivaSheet) has been developed by CivaTech Oncology, Inc. (Research Triangle Park, NC) for permanent brachytherapy. Distributed throughout the array are small plastic disks containing Pd-103 and gold foil shielding on one side to provide a directional dose distribution and facilitate imaging. This study evaluated dosimetry for the CivaSheet. Methods: Manufacturer-provided dimensional and compositional information for the device were compared to physical samples for validation of design information, then entered into the MCNP6 radiation transport code for dosimetry simulations. Three device sizes (6×6, 6×12, or 6×18 disk-arrays) were simulated as the membrane can be custom-sized preceding surgical placement. Dose to water was estimated with 0.01 cm resolution from the surface to 10 cm on both sides of the device. Because this is a novel device with calibration methods under development, results were normalized using DVHs to provide 90% prescription coverage to a plane positioned 0.5 cm from the front surfaces. This same normalization was used for creating isodose distributions. Results: Planar dose distributions of flat CivaSheets were relatively homogeneous with acceptable dose uniformity variations. Differences in the results between the differently sized CivaSheets were not significant. At 0.5 mm, 87% of the target volume was within the therapeutic dose range. Dose hotspots on the CivaSheet forward surfaces were directly above the disks. However, dose hotspots on the rear-facing surfaces were positioned between the disks. Doses in contact with the front surface were similar to those observed for currently available brachytherapy sources. Maximum doses that occurred on the rear surface were approximately 55 times lower than the dose on the front surface. Conclusion: Monte Carlo calculations validated the directional capabilities and advantageous dosimetry of the new Pd-103 brachytherapy device. It appears feasible to re

  20. Distribution over pT of direct secondary ha drons in hadron-hadron and hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Braun, V.M.

    1986-01-01

    Transverse momentum distributions of direct secondary hadrons produced in proton, pion and kaon collisons with nucleons and nuclei are calculated in the additive quark model. Results of calculations are compared to the experimental data on production of neutral strange particles

  1. Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

    Directory of Open Access Journals (Sweden)

    Jakub Ehrenberger

    2017-09-01

    Full Text Available This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordination is designed, in which not only some, but all the required types of short-circuit contributions are taken into account. In radial systems, if the pickup currents are correctly chosen, protection coordination for maximum contributions is enough to ensure selectivity times for all the required short-circuit types. In distributed generation systems, due to different contributions flowing through the primary and selective protections, coordination for maximum contributions is not enough, but all the short-circuit types must be taken into account, and the protection coordination becomes a complex problem. A possible solution to the problem, based on an appropriately designed optimization, has been proposed in the paper. By repeating a simple optimization considering only one short-circuit type, the protection coordination considering all the required short-circuit types has been achieved. To show the importance of considering all the types of short-circuit contributions, setting optimizations with one (the highest and all the types of short-circuit contributions have been performed. Finally, selectivity time values are explored throughout the entire protected section, and both the settings are compared.

  2. Distributed adaptive asymptotically consensus tracking control of uncertain Euler-Lagrange systems under directed graph condition.

    Science.gov (United States)

    Wang, Wei; Wen, Changyun; Huang, Jiangshuai; Fan, Huijin

    2017-11-01

    In this paper, a backstepping based distributed adaptive control scheme is proposed for multiple uncertain Euler-Lagrange systems under directed graph condition. The common desired trajectory is allowed totally unknown by part of the subsystems and the linearly parameterized trajectory model assumed in currently available results is no longer needed. To compensate the effects due to unknown trajectory information, a smooth function of consensus errors and certain positive integrable functions are introduced in designing virtual control inputs. Besides, to overcome the difficulty of completely counteracting the coupling terms of distributed consensus errors and parameter estimation errors in the presence of asymmetric Laplacian matrix, extra information transmission of local parameter estimates are introduced among linked subsystem and adaptive gain technique is adopted to generate distributed torque inputs. It is shown that with the proposed distributed adaptive control scheme, global uniform boundedness of all the closed-loop signals and asymptotically output consensus tracking can be achieved. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Direct numerical simulation of turbulent channel flow with spanwise alternatively distributed strips control

    Science.gov (United States)

    Ni, Weidan; Lu, Lipeng; Fang, Jian; Moulinec, Charles; Yao, Yufeng

    2018-05-01

    The effect of spanwise alternatively distributed strips (SADS) control on turbulent flow in a plane channel has been studied by direct numerical simulations to investigate the characteristics of large-scale streamwise vortices (LSSVs) induced by small-scale active wall actuation, and their potential in suppressing flow separation. SADS control is realized by alternatively arranging out-of-phase control (OPC) and in-phase control (IPC) wall actuations on the lower channel wall surface, in the spanwise direction. It is found that the coherent structures are suppressed or enhanced alternatively by OPC or IPC, respectively, leading to the formation of a vertical shear layer, which is responsible for the LSSVs’ presence. Large-scale low-speed region can also be observed above the OPC strips, which resemble large-scale low-speed streaks. LSSVs are found to be in a statistically-converged steady state and their cores are located between two neighboring OPC and IPC strips. Their motions contribute significantly to the momentum transport in the wall-normal and spanwise directions, demonstrating their potential ability to suppress flow separation.

  4. Minimal-Approximation-Based Distributed Consensus Tracking of a Class of Uncertain Nonlinear Multiagent Systems With Unknown Control Directions.

    Science.gov (United States)

    Choi, Yun Ho; Yoo, Sung Jin

    2017-03-28

    A minimal-approximation-based distributed adaptive consensus tracking approach is presented for strict-feedback multiagent systems with unknown heterogeneous nonlinearities and control directions under a directed network. Existing approximation-based consensus results for uncertain nonlinear multiagent systems in lower-triangular form have used multiple function approximators in each local controller to approximate unmatched nonlinearities of each follower. Thus, as the follower's order increases, the number of the approximators used in its local controller increases. However, the proposed approach employs only one function approximator to construct the local controller of each follower regardless of the order of the follower. The recursive design methodology using a new error transformation is derived for the proposed minimal-approximation-based design. Furthermore, a bounding lemma on parameters of Nussbaum functions is presented to handle the unknown control direction problem in the minimal-approximation-based distributed consensus tracking framework and the stability of the overall closed-loop system is rigorously analyzed in the Lyapunov sense.

  5. Fluorescence imaging of lattice re-distribution on step-index direct laser written Nd:YAG waveguide lasers

    Energy Technology Data Exchange (ETDEWEB)

    Martínez de Mendívil, Jon; Pérez Delgado, Alberto; Lifante, Ginés; Jaque, Daniel [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Ródenas, Airán [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Benayas, Antonio, E-mail: antonio.benayas@emt.inrs.ca [Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid 28049 (Spain); Institut National de la Recherche Scientifique, Centre – Énergie Matériaux et Télécommunications, 1650, Boul. Lionel Boulet Varennes, Quebec J3X 1S2 (Canada); Aguiló, Magdalena; Diaz, Francesc [Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Tarragona 43007 (Spain); Kar, Ajoy K. [Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2015-01-14

    The laser performance and crystalline micro-structural properties of near-infrared step-index channel waveguides fabricated inside Neodymium doped YAG laser ceramics by means of three-dimensional sub-picosecond pulse laser direct writing are reported. Fluorescence micro-mapping of the waveguide cross-sections reveals that an essential crystal lattice re-distribution has been induced after short pulse irradiation. Such lattice re-distribution is evidenced at the waveguide core corresponding to the laser written refractive index increased volume. The waveguides core surroundings also present diverse changes including slight lattice disorder and bi-axial strain fields. The step-index waveguide laser performance is compared with previous laser fabricated waveguides with a stress-optic guiding mechanism in absence of laser induced lattice re-distribution.

  6. Direct assignment of molecular vibrations via normal mode analysis of the neutron dynamic pair distribution function technique

    International Nuclear Information System (INIS)

    Fry-Petit, A. M.; Sheckelton, J. P.; McQueen, T. M.; Rebola, A. F.; Fennie, C. J.; Mourigal, M.; Valentine, M.; Drichko, N.

    2015-01-01

    For over a century, vibrational spectroscopy has enhanced the study of materials. Yet, assignment of particular molecular motions to vibrational excitations has relied on indirect methods. Here, we demonstrate that applying group theoretical methods to the dynamic pair distribution function analysis of neutron scattering data provides direct access to the individual atomic displacements responsible for these excitations. Applied to the molecule-based frustrated magnet with a potential magnetic valence-bond state, LiZn 2 Mo 3 O 8 , this approach allows direct assignment of the constrained rotational mode of Mo 3 O 13 clusters and internal modes of MoO 6 polyhedra. We anticipate that coupling this well known data analysis technique with dynamic pair distribution function analysis will have broad application in connecting structural dynamics to physical properties in a wide range of molecular and solid state systems

  7. Factors affecting the potential of direct load control for non-generating utilities. Final report. [Distribution and wholesale power supply interaction

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-04-01

    Several alternatives are available for achieving load management, including direct or voluntary control of customer loads, customer or utility energy storage systems for diurnal load shifting, and expanded interconnection and operation of electric power systems. All of these alternatives are available to the fully integrated (generating, transmitting and distributing) electric utility and the analysis of their effects encompasses the power supply and delivery system. However, the costs and benefits of the alternatives to the fully integrated electric utility are perhaps not so obvious. Therefore, by considering a non-generating utility, this analysis focuses upon the distribution system and wholesale power supply interaction as a step toward an analysis including the power supply and delivery system. This report develops an analysis procedure and discusses some of the relevant factors to be consdered in the application of direct load control for a non-generating utility system. The analysis concentrates on the distribution system only to determine the effect of rates and payback as a result of direct load control. Thus, the study is responsive to the specific needs of the non-generating utility. This analysis of direct load control encompasses the determination of those loads amenable to control, the selection of a suitable one-way communications system to rend control and the estimation of expected benefits and costs. The complementary functions to the application of direct load control such as automatic meter reading via the addition of a bi-directional communications system and voltage control are not included in the analysis but are detailed for future consideration.

  8. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi; N'Doye, Ibrahima; Laleg-Kirati, Taous-Meriem

    2015-01-01

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  9. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi

    2015-09-21

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  10. Combined local current distribution measurements and high resolution neutron radiography of operating direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Alexander; Wippermann, Klaus [Forschungszentrum Juelich GmbH (Germany). Inst. of Energy Research, IEF-3: Fuel Cells; Sanders, Tilman [RWTH Aachen (DE). Inst. for Power Electronics and Electrical Drives (ISEA); Arlt, Tobias [Helmholtz Centre Berlin (Germany). Inst. for Applied Materials

    2010-07-01

    Neutron radiography allows the investigation of the local fluid distribution in direct methanol fuel cells (DMFCs) under operating conditions. Spatial resolutions in the order of some tens of micrometers at the full test cell area are achieved. This offers the possibility to study practice-oriented, large stack cells with an active area of several hundred cm{sup 2} as well as specially designed, small test cells with an area of some cm{sup 2}. Combined studies of high resolution neutron radiography and segmented cell measurements are especially valuable, because they enable a correlation of local fluid distribution and local performance [1, 2]. The knowledge of this interdependency is essential to optimise the water management and performance respecting a homogeneous fluid, current and temperature distribution and to achieve high performance and durability of DMFCs. (orig.)

  11. Direct numerical solution of the Ornstein-Zernike integral equation and spatial distribution of water around hydrophobic molecules

    Science.gov (United States)

    Ikeguchi, Mitsunori; Doi, Junta

    1995-09-01

    The Ornstein-Zernike integral equation (OZ equation) has been used to evaluate the distribution function of solvents around solutes, but its numerical solution is difficult for molecules with a complicated shape. This paper proposes a numerical method to directly solve the OZ equation by introducing the 3D lattice. The method employs no approximation the reference interaction site model (RISM) equation employed. The method enables one to obtain the spatial distribution of spherical solvents around solutes with an arbitrary shape. Numerical accuracy is sufficient when the grid-spacing is less than 0.5 Å for solvent water. The spatial water distribution around a propane molecule is demonstrated as an example of a nonspherical hydrophobic molecule using iso-value surfaces. The water model proposed by Pratt and Chandler is used. The distribution agrees with the molecular dynamics simulation. The distribution increases offshore molecular concavities. The spatial distribution of water around 5α-cholest-2-ene (C27H46) is visualized using computer graphics techniques and a similar trend is observed.

  12. Effects on Subtalar Joint Stress Distribution After Cannulated Screw Insertion at Different Positions and Directions.

    Science.gov (United States)

    Yuan, Cheng-song; Chen, Wan; Chen, Chen; Yang, Guang-hua; Hu, Chao; Tang, Kang-lai

    2015-01-01

    We investigated the effects on subtalar joint stress distribution after cannulated screw insertion at different positions and directions. After establishing a 3-dimensional geometric model of a normal subtalar joint, we analyzed the most ideal cannulated screw insertion position and approach for subtalar joint stress distribution and compared the differences in loading stress, antirotary strength, and anti-inversion/eversion strength among lateral-medial antiparallel screw insertion, traditional screw insertion, and ideal cannulated screw insertion. The screw insertion approach allowing the most uniform subtalar joint loading stress distribution was lateral screw insertion near the border of the talar neck plus medial screw insertion close to the ankle joint. For stress distribution uniformity, antirotary strength, and anti-inversion/eversion strength, lateral-medial antiparallel screw insertion was superior to traditional double-screw insertion. Compared with ideal cannulated screw insertion, slightly poorer stress distribution uniformity and better antirotary strength and anti-inversion/eversion strength were observed for lateral-medial antiparallel screw insertion. Traditional single-screw insertion was better than double-screw insertion for stress distribution uniformity but worse for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion was slightly worse for stress distribution uniformity than was ideal cannulated screw insertion but superior to traditional screw insertion. It was better than both ideal cannulated screw insertion and traditional screw insertion for anti-rotary strength and anti-inversion/eversion strength. Lateral-medial antiparallel screw insertion is an approach with simple localization, convenient operation, and good safety. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Theory for site-site pair distribution functions of molecular fluids. II. Approximations for the Percus--Yevick site-site direct correlation functions

    International Nuclear Information System (INIS)

    Johnson, E.

    1977-01-01

    A theory for site-site pair distribution functions of molecular fluids is derived from the Ornstein-Zernike equation. Atom-atom pair distribution functions of this theory which were obtained by using different approximations for the Percus-Yevick site-site direct correlation functions are compared

  14. Directional Wigner-Ville distribution and its application for rotating-machinery condition monitoring

    International Nuclear Information System (INIS)

    Kim, Dong Wan; Ha, Jae HOng; Shin, Hae Gon; Lee, Yoon Hee; Kim, Young Baik

    1996-01-01

    Vibration analysis is one of the most powerful tools available for the detection and isolation of incipient faults in mechanical systems. The methods of vibration analysis in use today and under continuous study are broad band vibration monitoring, time domain analysis, and frequency domain analysis. In recent years, great interest has been generated concerning the use of time-frequency representation and its application for a machinery diagnostics and condition monitoring system. The objective of the research described in this paper was to develop a new diagnostic tool for the rotating machinery. This paper introduces a new time-frequency representation, Directional Wigner-Ville Distribution, which analyses the time-frequency structure of the rotating machinery vibration

  15. A direct and at nanometer scale study of electrical charge distribution on membranes of alive cells

    Directory of Open Access Journals (Sweden)

    Marlière Christian

    2016-01-01

    Full Text Available In this paper is presented an innovative method to map in-vivo and at nanometer scale the electrical charge distribution on membranes of alive cells. It relies on a new atomic force microscopy (AFM mode based on an electro-mechanical coupling effect. Furthermore, an additional electrical signal detected by both the deflection of the AFM cantilever and simultaneous direct current measurements was detected at low scanning rates. It was attributed to the detection of the current stemming from ionic channels. It opens a new way to directly investigate in situ biological electrical surface processes involved in bacterial adhesion, biofilm formation, microbial fuel cells, etc.

  16. Seedling establishment and distribution of direct radiation in slit-shaped openings of Norway spruce forests in the intermediate Alps

    International Nuclear Information System (INIS)

    Brang, P.

    1996-01-01

    Direct radiation is crucial for Norway spruce (Picea abies (L.) Karst.) seedling establishment in high-montane and subalpine spruce forests. Fisheye photography was used to estimate the daily distribution of direct radiation in small forest openings on a north-northwest and a south facing slope near Sedrun (Grisons, Switzerland). In slit-shaped openings on the north-northwest facing slope long sunflecks mostly occurred in the afternoon, when the sun shines parallel to the slit axis. This is in accordance to the silvicultural intention. However, since the stands are clumpy and therefore pervious to sunlight, the daily sunfleck distribution is fairly even notwithstanding the slit orientation, and direct radiation at noon is the dominant form of incident energy. In small circular to rectangular openings on the south facing slope direct radiation peaks at noontide. A seeding trial imitating natural seedling establishment was set in place in openings on both slopes. Based on this trial, the relations among seedling establishment, aspect, slit shape, size, and orientation are discussed for Norway spruce forests in the intermediate Alps. The directional weather factors such as radiation and precipitation can be highly influenced by slits, which is why suitable microclimate for seedling establishment can be promoted provided the slits are oriented appropriately. Slits in which the most insolated edges are oriented windward are especially favourable

  17. Effect of modulation of the particle size distributions in the direct solid analysis by total-reflection X-ray fluorescence

    Science.gov (United States)

    Fernández-Ruiz, Ramón; Friedrich K., E. Josue; Redrejo, M. J.

    2018-02-01

    The main goal of this work was to investigate, in a systematic way, the influence of the controlled modulation of the particle size distribution of a representative solid sample with respect to the more relevant analytical parameters of the Direct Solid Analysis (DSA) by Total-reflection X-Ray Fluorescence (TXRF) quantitative method. In particular, accuracy, uncertainty, linearity and detection limits were correlated with the main parameters of their size distributions for the following elements; Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba and Pb. In all cases strong correlations were finded. The main conclusion of this work can be resumed as follows; the modulation of particles shape to lower average sizes next to a minimization of the width of particle size distributions, produce a strong increment of accuracy, minimization of uncertainties and limit of detections for DSA-TXRF methodology. These achievements allow the future use of the DSA-TXRF analytical methodology for development of ISO norms and standardized protocols for the direct analysis of solids by mean of TXRF.

  18. Three-dimensional direct laser written graphitic electrical contacts to randomly distributed components

    Science.gov (United States)

    Dorin, Bryce; Parkinson, Patrick; Scully, Patricia

    2018-04-01

    The development of cost-effective electrical packaging for randomly distributed micro/nano-scale devices is a widely recognized challenge for fabrication technologies. Three-dimensional direct laser writing (DLW) has been proposed as a solution to this challenge, and has enabled the creation of rapid and low resistance graphitic wires within commercial polyimide substrates. In this work, we utilize the DLW technique to electrically contact three fully encapsulated and randomly positioned light-emitting diodes (LEDs) in a one-step process. The resolution of the contacts is in the order of 20 μ m, with an average circuit resistance of 29 ± 18 kΩ per LED contacted. The speed and simplicity of this technique is promising to meet the needs of future microelectronics and device packaging.

  19. Adjustable Parameter-Based Distributed Fault Estimation Observer Design for Multiagent Systems With Directed Graphs.

    Science.gov (United States)

    Zhang, Ke; Jiang, Bin; Shi, Peng

    2017-02-01

    In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.

  20. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: direct brine release

    International Nuclear Information System (INIS)

    Stoelzel, D.M.; O'Brien, D.G.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Smith, L.N.

    2000-01-01

    The following topics related to the treatment of direct brine releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e. aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented analyses indicate that direct brine releases do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for direct brine releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

  1. Direct calculation of unambiguous electron-density distributions of Langmuir-Blodgett films normal to the membrane plane

    International Nuclear Information System (INIS)

    Frieling, M. von; Bradaczek, H.

    1990-01-01

    In regard to X-ray diffraction, Langmuir-Blodgett (LB) films consisting of lipid bilayers represent a 'one-dimensional crystal' with a very small number of unit cells in the direction of stacking. Such bounded systems yield X-ray diffraction diagrams which, in certain respects, contain more information than those of the conventional effectively infinite single crystals. This additional information consists of the profiles of the broadened reflections and their dislocation from the reciprocal-lattice points. These profiles are specific for each different structure and hence enable the direct calculation of unambiguous electron-density distributions from a single set of intensity data. At first, the Q function (the generalized Patterson function), i.e. the distance statistics of the structure sought after is calculated from the intensity data. Thereafter, the unambiguous convolution square root of the Q function must be determined, which is identical to the unknown electron-density distribution. For this purpose two mathematically completely different methods were established and compared. They were applied to diffraction patterns of Langmuir-Blodgett films of simple synthetic lipids with characteristic molecular subunits and showed identical results within the experimental resolution. This verifies the structures and the methods to calculate them. Furthermore, all features of the simple structures were compatible with the expectations. All one-dimensional electron-density distributions showed the common features of lipid bilayers. The characteristic molecular subunits can be recognized and reveal some interesting details. In general, they yield information about orientation, conformation and localization of molecular subunits and membrane components. (orig.)

  2. Principles for scaling of distributed direct potable water reuse systems: a modeling study.

    Science.gov (United States)

    Guo, Tianjiao; Englehardt, James D

    2015-05-15

    Scaling of direct potable water reuse (DPR) systems involves tradeoffs of treatment facility economy-of-scale, versus cost and energy of conveyance including energy for upgradient distribution of treated water, and retention of wastewater thermal energy. In this study, a generalized model of the cost of DPR as a function of treatment plant scale, assuming futuristic, optimized conveyance networks, was constructed for purposes of developing design principles. Fractal landscapes representing flat, hilly, and mountainous topographies were simulated, with urban, suburban, and rural housing distributions placed by modified preferential growth algorithm. Treatment plants were allocated by agglomerative hierarchical clustering, networked to buildings by minimum spanning tree. Simulations assume advanced oxidation-based DPR system design, with 20-year design life and capability to mineralize chemical oxygen demand below normal detection limits, allowing implementation in regions where disposal of concentrate containing hormones and antiscalants is not practical. Results indicate that total DPR capital and O&M costs in rural areas, where systems that return nutrients to the land may be more appropriate, are high. However, costs in urban/suburban areas are competitive with current water/wastewater service costs at scales of ca. one plant per 10,000 residences. This size is relatively small, and costs do not increase significantly until plant service areas fall below 100 to 1000 homes. Based on these results, distributed DPR systems are recommended for consideration for urban/suburban water and wastewater system capacity expansion projects. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A Joint Optimal Decision on Shipment Size and Carbon Reduction under Direct Shipment and Peddling Distribution Strategies

    Directory of Open Access Journals (Sweden)

    Daiki Min

    2017-11-01

    Full Text Available Recently, much research has focused on lowering carbon emissions in logistics. This paper attempts to contribute to the literature on the joint shipment size and carbon reduction decisions by developing novel models for distribution systems under direct shipment and peddling distribution strategies. Unlike the literature that has simply investigated the effects of carbon costs on operational decisions, we address how to reduce carbon emissions and logistics costs by adjusting shipment size and making an optimal decision on carbon reduction investment. An optimal decision is made by analyzing the distribution cost including not only logistics and carbon trading costs but also the cost for adjusting carbon emission factors. No research has explicitly considered the two sources of carbon emissions, but we develop a model covering the difference in managing carbon emissions from transportation and storage. Structural analysis guides how to determine an optimal shipment size and emission factors in a closed form. Moreover, we analytically prove the possibility of reducing the distribution cost and carbon emissions at the same time. Numerical analysis follows validation of the results and demonstrates some interesting findings on carbon and distribution cost reduction.

  4. Status of the Direct Data Distribution (D(exp 3)) Experiment

    Science.gov (United States)

    Wald, Lawrence

    2001-01-01

    NASA Glenn Research Center's Direct Data Distribution (D3) project will demonstrate an advanced, high-performance communications system that transmits information from an advanced technology payload carried by a NASA spacecraft in low Earth orbit (LEO) to a small receiving terminal on Earth. The space-based communications package will utilize a solid-state, K-band phased-array antenna that electronically steers the radiated energy beam toward a low-cost, tracking ground terminal, thereby providing agile, vibration-free, electronic steering at reduced size and weight with increased reliability. The array-based link will also demonstrate new digital processing technology that will allow the transmission of substantially increased amounts of latency-tolerant data collected from the LEO spacecraft directly to NASA field centers, principal investigators, or into the commercial terrestrial communications network. The technologies demonstrated by D3 will facilitate NASA's transition from using Government-owned communication assets to using commercial communication services. The hardware for D3 will incorporate advanced technology components developed under the High Rate Data Delivery (HRDD) Thrust Area of NASA's Office of Aerospace Technology Space Base Program at Glenn's Communications Technology Division. The flight segment components will include the electrically steerable phased-array antenna, which is being built by the Raytheon System Corporation and utilizes monolithic microwave integrated circuit (MMIC) technology operating at 19.05 GHz; and the digital encoder/modulator chipset, which uses four-channel orthogonal frequency division multiplexing (OFDM). The encoder/modulator will use a chipset developed by SICOM, Inc., which is both bandwidth and power efficient. The ground segment components will include a low-cost, open-loop tracking ground terminal incorporating a cryoreceiver to minimize terminal size without compromising receiver capability. The project is

  5. Non-Maxwellian electron distributions resulting from direct laser acceleration in near-critical plasmas

    Directory of Open Access Journals (Sweden)

    T. Toncian

    2016-01-01

    Full Text Available The irradiation of few-nm-thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse. The targets decompress to near and lower than critical densities with plasmas extending over few micrometers, i.e. multiple wavelengths. The interaction of the main pulse with such a highly localized but inhomogeneous target leads to the generation of a short channel and further self-focusing of the laser beam. Experiments at the Glass Hybrid OPCPA Scaled Test-bed (GHOST laser system at University of Texas, Austin using such targets measured non-Maxwellian, peaked electron distribution with large bunch charge and high electron density in the laser propagation direction. These results are reproduced in 2D PIC simulations using the EPOCH code, identifying direct laser acceleration (DLA [1] as the responsible mechanism. This is the first time that DLA has been observed to produce peaked spectra as opposed to broad, Maxwellian spectra observed in earlier experiments [2]. This high-density electrons have potential applications as injector beams for a further wakefield acceleration stage as well as for pump-probe applications.

  6. Energy and direction distribution of neutrons in workplace fields: Implication of the results from the EVIDOS project for the set-up of simulated workplace fields

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; Lacoste, V.; Reginatto, M.; Zimbal, A.

    2007-01-01

    Workplace neutron spectra from nuclear facilities obtained within the European project EVIDOS are compared with those of the simulated workplace fields CANEL and SIGMA and fields set-up with radionuclide sources at the PTB. Contributions of neutrons to ambient dose equivalent and personal dose equivalent are given in three energy intervals (for thermal, intermediate and fast neutrons) together with the corresponding direction distribution, characterised by three different types of distributions (isotropic, weakly directed and directed). The comparison shows that none of the simulated workplace fields investigated here can model all the characteristics of the fields observed at power reactors. (authors)

  7. Pull-Based Distributed Event-Triggered Consensus for Multiagent Systems With Directed Topologies.

    Science.gov (United States)

    Yi, Xinlei; Lu, Wenlian; Chen, Tianping

    2017-01-01

    This paper mainly investigates consensus problem with a pull-based event-triggered feedback control. For each agent, the diffusion coupling feedbacks are based on the states of its in-neighbors at its latest triggering time, and the next triggering time of this agent is determined by its in-neighbors' information. The general directed topologies, including irreducible and reducible cases, are investigated. The scenario of distributed continuous communication is considered first. It is proved that if the network topology has a spanning tree, then the event-triggered coupling algorithm can realize the consensus for the multiagent system. Then, the results are extended to discontinuous communication, i.e., self-triggered control, where each agent computes its next triggering time in advance without having to observe the system's states continuously. The effectiveness of the theoretical results is illustrated by a numerical example finally.

  8. Interpreting dark matter direct detection independently of the local velocity and density distribution

    International Nuclear Information System (INIS)

    Fox, Patrick J.; Kribs, Graham D.; Tait, Tim M. P.

    2011-01-01

    We demonstrate precisely what particle physics information can be extracted from a single direct detection observation of dark matter while making absolutely no assumptions about the local velocity distribution and local density of dark matter. Our central conclusions follow from a very simple observation: the velocity distribution of dark matter is positive definite, f(v)≥0. We demonstrate the utility of this result in several ways. First, we show a falling deconvoluted recoil spectrum (deconvoluted of the nuclear form factor), such as from ordinary elastic scattering, can be 'mocked up' by any mass of dark matter above a kinematic minimum. As an example, we show that dark matter much heavier than previously considered can explain the CoGeNT excess. Specifically, m χ Ge can be in just as good agreement as light dark matter, while m χ >m Ge depends on understanding the sensitivity of xenon to dark matter at very low recoil energies, E R < or approx. 6 keVnr. Second, we show that any rise in the deconvoluted recoil spectrum represents distinct particle physics information that cannot be faked by an arbitrary f(v). As examples of resulting nontrivial particle physics, we show that inelastic dark matter and dark matter with a form factor can both yield such a rise.

  9. Direct-push delivery of dye tracers for direct documentation of solute distribution in clay till

    DEFF Research Database (Denmark)

    Christiansen, Camilla Maymann; Damgaard, Ida; Broholm, Mette Martina

    2012-01-01

    at several locations and depth intervals [2.5-9.5 m below surface (b.s.)], representing both the vadose and saturated zones. Extensive coring to 12 m b.s. and excavation to 5 m b.s. were carried out to identify the lateral and vertical extent of tracer distribution. A tracer distribution radius of minimum 1...

  10. Distribution of transverse distances in directed animals

    CERN Document Server

    Sumedha

    2003-01-01

    We relate phi(x, s), the average number of sites at a transverse distance x in the directed animals with s sites in d transverse dimensions, to the two-point correlation function of a lattice gas with nearest neighbour exclusion in d dimensions. For large s, phi(x, s) has the scaling form s/R sup d sub s f(|x|/R sub s), where R sub s is the root-mean square radius of gyration of animals of s sites. We determine the exact scaling function for d = 1 to be f(r) = sq root pi/2 sq root 3 erfc(r/sq root 3). We also show that phi(x = 0, s) can be determined in terms of the animal number generating function of the directed animals.

  11. Amyloplast Distribution Directs a Root Gravitropic Reaction

    Science.gov (United States)

    Kordyum, Elizabeth

    Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 μ in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence

  12. Direct observation of radial distribution change during tensile deformation of metallic glass by high energy X-ray diffraction method

    Energy Technology Data Exchange (ETDEWEB)

    Nasu, Toshio, E-mail: nasu@kekexafs.kj.yamagata-u.ac.j [Faculty of Education, Arts and Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata, Yamagata, 990-8560 (Japan); Sasaki, Motokatsu [Faculty of Education, Arts and Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata, Yamagata, 990-8560 (Japan); Usuki, Takeshi; Sekine, Mai [Faculty of Science, Yamagata University, Yamagata 990-8560 (Japan); Takigawa, Yorinobu; Higashi, Kenji [Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531 (Japan); Kohara, Shinji [Japan Synchrotron Radiation Research Institute, Harima Science Garden City, Sayo town, Hyogo 679-5198 (Japan); Sakurai, Masaki; Wei Zhang; Inoue, Akihisa [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2009-08-26

    The purpose of this research is to investigate the micro-mechanism of deformation behavior of metallic glasses. We report the results of direct observations of short-range and medium-range structural change during tensile deformation of metallic glasses by high energy X-ray diffraction method. Cu{sub 50}Zr{sub 50} and Ni{sub 30}Zr{sub 70} metallic glass samples in the ribbon shape (1.5 mm width and 25 mum) were made by using rapid quenching method. Tensile deformation added to the sample was made by using special equipment adopted for measuring the high energy X-ray diffraction. The peaks in pair distribution function g(r) for Cu{sub 50}Zr{sub 50} and N{sub 30}iZr{sub 70} metallic glasses move zigzag into front and into rear during tensile deformation. These results of direct observation on atomic distribution change for Cu{sub 50}Zr{sub 50} and Ni{sub 30}Zr{sub 70} metallic glass ribbons during tensile deformation suggest that the micro-relaxations occur.

  13. TH-AB-201-05: Determining the Direction Distribution of the Primary Radiation for a Cyberknife-M6

    International Nuclear Information System (INIS)

    Henzen, D; Schmidhalter, D; Volken, W; Mackeprang, P-H; Malthaner, M; K Fix, M; Manser, P; C Zanella, C

    2016-01-01

    Purpose: Radiation protection regulatory differentiates between primary and scatter radiation. Whereas for conventional clinical linear accelerators the solid angle for primary radiation is planar, the Cyberknife (Accuray Inc., Sunnyvale, CA) may point its beam in all spatial directions. In order to be able to judge on radiation protection calculations for a Cyberknife-M6 vault, the direction distribution for delivered plans was evaluated based on clinical experiences. Methods: The log-files of 121 delivered patient treatment plans were exported, divided into cranial and extra-cranial treatments and the delivered monitor units (MU) together with the corresponding beam directions were analyzed. This MU-weighted spatial distribution was then projected to a 9.5 × 5.9 × 3.9 m 3 vault, generating an “intensity map” using a binning of 50 × 50 cm 2 . The factor of direction (FOD) is reported as a fraction of the total applied MUs to the walls, ceiling and floor in the perspective of a patient lying in head-first-supine position on the couch. In this study, the term intFOD refers to the integral FOD and maxFOD refers to the maximal FOD for a single bin. Results: For all kind of treatments and collimators, intFOD and maxFOD for the wall behind the patient’s head is 0.0. The intFOD for the floor varies between 0.65 and 0.74. For the ceiling, maxFOD is 0.002 and 0.0 for cranial and extra-cranial cases, respectively. The intFOD for the wall at the patient’s feet, is 0.094 for cranial and 0.005 for extra-cranial cases. There is nearly no difference between the maxFOD of the right and left wall for cranial cases, whereas for extra-cranial cases these numbers differ by a factor of 1.75. Conclusion: The varying FODs for the Cyberknife were quantified based on delivered treatment plans. These findings are helpful regarding the design of Cyberknife vaults.

  14. Determinants of foreign direct investment in Tunisia: Empirical assessment based on an application of the autoregressive distributed Lag model

    Directory of Open Access Journals (Sweden)

    Teheni El Ghak

    2017-05-01

    Full Text Available In recent years, the changing economic and political environment in Tunisia led to a renewed interest on the drivers of foreign direct investment, given its potential important gains. In this study, we investigated the impact of various factors over the period 1980-2012. In doing this, three categories of determinants were considered: economic, political and sociocultural variables. Empirical findings drawn from the autoregressive distributed lag bounds testing approach show that variation in foreign direct investment inflow in the short-run and long-run is affected by the majority of variables considered, except exchange rate, urban population and gross domestic savings. As a matter of policy, it is essential that government should continue its efforts to create a macroeconomic environment which is attractive to foreign direct investment.

  15. Simulation of magnetic induction distribution in a coaxial linear motor with axial and radial direction of permanent magnets magnetization

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-03-01

    Full Text Available The paper presents results of computer simulation and experimental study of magnetic induction distribution in a coaxial linear motor air gap throughout the length of the runner active part at different heights of the air gap between the runner and the inductor magnetic core for motors with axial and radial direction of the permanent magnets magnetization.

  16. Frequency Locking and Monitoring Based on Bi-directional Terahertz Radiation of a 3rd-Order Distributed Feedback Quantum Cascade Laser

    NARCIS (Netherlands)

    Van Marrewijk, N.; Mirzaei, B.; Hayton, D.; Gao, J.R.; Kao, T.Y.; Hu, Q.; Reno, J.L.

    2015-01-01

    We have performed frequency locking of a dual, forward reverse emitting third-order distributed feedback quantum cascade laser (QCL) at 3.5 THz. By using both directions of THz emission in combination with two gas cells and two power detectors, we can for the first time perform frequency

  17. Direct comparison between the angular distributions of the erythemal and eye-damaging UV irradiances: a pilot study.

    Science.gov (United States)

    Schouten, P; Parisi, A V

    2011-02-07

    Several broadband ultraviolet (UV) radiation angular distribution investigations have been previously presented. As the biologically damaging effectiveness of UV radiation is known to be wavelength dependent, it is necessary to expand this research into the distribution of the spectral UV. UV radiation is also susceptible to Rayleigh and Mie scattering processes, both of which are completely wavelength dependent. Additionally, the majority of previous measurements detailing the biologically damaging effect of spectral UV radiation have been oriented with respect to the horizontal plane or in a plane directed towards the sun (sun-normal), with the irradiance weighted against action spectra formulated specifically for human skin and tissue. However, the human body consists of very few horizontal or sun-normal surfaces. Extending the previous research by measuring the distribution of the spectral irradiance across the sky for the complete terrestrial solar UV waveband and weighting it against erythemal, photoconjunctivital and photokeratital action spectra allowed for the analysis of the differences between the biologically effective irradiance (UV(BE)) values intercepted at different orientations and the effect of scattering processes upon the homogeneity of these UV(BE) distributions. It was established that under the local atmospheric environment, the distribution profile of the UV(BE) for each biological response was anisotropic, with the highest intensities generally intercepted at inclination angles situated between the horizontal and vertical planes along orientations closely coinciding with the sun-normal. A finding from this was that the angular distributions of the erythemal UV(BE) and the photoconjunctivital UV(BE) were different, due to the differential scattering between the shorter and longer UV wavelengths within the atmosphere. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Direct measurements show decreasing methane emissions from natural gas local distribution systems in the United States.

    Science.gov (United States)

    Lamb, Brian K; Edburg, Steven L; Ferrara, Thomas W; Howard, Touché; Harrison, Matthew R; Kolb, Charles E; Townsend-Small, Amy; Dyck, Wesley; Possolo, Antonio; Whetstone, James R

    2015-04-21

    Fugitive losses from natural gas distribution systems are a significant source of anthropogenic methane. Here, we report on a national sampling program to measure methane emissions from 13 urban distribution systems across the U.S. Emission factors were derived from direct measurements at 230 underground pipeline leaks and 229 metering and regulating facilities using stratified random sampling. When these new emission factors are combined with estimates for customer meters, maintenance, and upsets, and current pipeline miles and numbers of facilities, the total estimate is 393 Gg/yr with a 95% upper confidence limit of 854 Gg/yr (0.10% to 0.22% of the methane delivered nationwide). This fraction includes emissions from city gates to the customer meter, but does not include other urban sources or those downstream of customer meters. The upper confidence limit accounts for the skewed distribution of measurements, where a few large emitters accounted for most of the emissions. This emission estimate is 36% to 70% less than the 2011 EPA inventory, (based largely on 1990s emission data), and reflects significant upgrades at metering and regulating stations, improvements in leak detection and maintenance activities, as well as potential effects from differences in methodologies between the two studies.

  19. Resummation of transverse momentum distributions in distribution space

    International Nuclear Information System (INIS)

    Ebert, Markus A.; Tackmann, Frank J.

    2016-11-01

    Differential spectra in observables that resolve additional soft or collinear QCD emissions exhibit Sudakov double logarithms in the form of logarithmic plus distributions. Important examples are the total transverse momentum q_T in color-singlet production, N-jettiness (with thrust or beam thrust as special cases), but also jet mass and more complicated jet substructure observables. The all-order logarithmic structure of such distributions is often fully encoded in differential equations, so-called (renormalization group) evolution equations. We introduce a well-defined technique of distributional scale setting, which allows one to treat logarithmic plus distributions like ordinary logarithms when solving these differential equations. In particular, this allows one (through canonical scale choices) to minimize logarithmic contributions in the boundary terms of the solution, and to obtain the full distributional logarithmic structure from the solution's evolution kernel directly in distribution space. We apply this technique to the q_T distribution, where the two-dimensional nature of convolutions leads to additional difficulties (compared to one-dimensional cases like thrust), and for which the resummation in distribution (or momentum) space has been a long-standing open question. For the first time, we show how to perform the RG evolution fully in momentum space, thereby directly resumming the logarithms [ln"n(q"2_T/Q"2)/q"2_T]_+ appearing in the physical q_T distribution. The resummation accuracy is then solely determined by the perturbative expansion of the associated anomalous dimensions.

  20. AIRGAP MAGNETIC INDUCTION DISTRIBUTION IN A COAXIALLY-LINEAR SYNCHRONOUS MOTOR WITH AXIAL AND RADIAL DIRECTION OF THE RUNNER PERMANENT MAGNETS MAGNETIZATION

    Directory of Open Access Journals (Sweden)

    Abbasian Mohsen

    2013-02-01

    Full Text Available Results of theoretical and experimental research on magnetic induction distribution in the air gap of a coaxially-linear synchronous motor with reciprocal motion within the pole pitch and axial and radial direction of the permanent magnets magnetization are presented.

  1. Resummation of transverse momentum distributions in distribution space

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Markus A.; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2016-11-15

    Differential spectra in observables that resolve additional soft or collinear QCD emissions exhibit Sudakov double logarithms in the form of logarithmic plus distributions. Important examples are the total transverse momentum q{sub T} in color-singlet production, N-jettiness (with thrust or beam thrust as special cases), but also jet mass and more complicated jet substructure observables. The all-order logarithmic structure of such distributions is often fully encoded in differential equations, so-called (renormalization group) evolution equations. We introduce a well-defined technique of distributional scale setting, which allows one to treat logarithmic plus distributions like ordinary logarithms when solving these differential equations. In particular, this allows one (through canonical scale choices) to minimize logarithmic contributions in the boundary terms of the solution, and to obtain the full distributional logarithmic structure from the solution's evolution kernel directly in distribution space. We apply this technique to the q{sub T} distribution, where the two-dimensional nature of convolutions leads to additional difficulties (compared to one-dimensional cases like thrust), and for which the resummation in distribution (or momentum) space has been a long-standing open question. For the first time, we show how to perform the RG evolution fully in momentum space, thereby directly resumming the logarithms [ln{sup n}(q{sup 2}{sub T}/Q{sup 2})/q{sup 2}{sub T}]{sub +} appearing in the physical q{sub T} distribution. The resummation accuracy is then solely determined by the perturbative expansion of the associated anomalous dimensions.

  2. Resummation of transverse momentum distributions in distribution space

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Markus A.; Tackmann, Frank J. [Theory Group, Deutsches Elektronen-Synchrotron (DESY),D-22607 Hamburg (Germany)

    2017-02-22

    Differential spectra in observables that resolve additional soft or collinear QCD emissions exhibit Sudakov double logarithms in the form of logarithmic plus distributions. Important examples are the total transverse momentum q{sub T} in color-singlet production, N-jettiness (with thrust or beam thrust as special cases), but also jet mass and more complicated jet substructure observables. The all-order logarithmic structure of such distributions is often fully encoded in differential equations, so-called (renormalization group) evolution equations. We introduce a well-defined technique of distributional scale setting, which allows one to treat logarithmic plus distributions like ordinary logarithms when solving these differential equations. In particular, this allows one (through canonical scale choices) to minimize logarithmic contributions in the boundary terms of the solution, and to obtain the full distributional logarithmic structure from the solution’s evolution kernel directly in distribution space. We apply this technique to the q{sub T} distribution, where the two-dimensional nature of convolutions leads to additional difficulties (compared to one-dimensional cases like thrust), and for which the resummation in distribution (or momentum) space has been a long-standing open question. For the first time, we show how to perform the RG evolution fully in momentum space, thereby directly resumming the logarithms [ln{sup n} (q{sub T}{sup 2}/Q{sup 2})/q{sub T}{sup 2}]{sub +} appearing in the physical q{sub T} distribution. The resummation accuracy is then solely determined by the perturbative expansion of the associated anomalous dimensions.

  3. Evolution of a Directional Wave Spectrum in a 3D Marginal Ice Zone with Random Floe Size Distribution

    Science.gov (United States)

    Montiel, F.; Squire, V. A.

    2013-12-01

    A new ocean wave/sea-ice interaction model is proposed that simulates how a directional wave spectrum evolves as it travels through a realistic marginal ice zone (MIZ), where wave/ice dynamics are entirely governed by coherent conservative wave scattering effects. Field experiments conducted by Wadhams et al. (1986) in the Greenland Sea generated important data on wave attenuation in the MIZ and, particularly, on whether the wave spectrum spreads directionally or collimates with distance from the ice edge. The data suggest that angular isotropy, arising from multiple scattering by ice floes, occurs close to the edge and thenceforth dominates wave propagation throughout the MIZ. Although several attempts have been made to replicate this finding theoretically, including by the use of numerical models, none have confronted this problem in a 3D MIZ with fully randomised floe distribution properties. We construct such a model by subdividing the discontinuous ice cover into adjacent infinite slabs of finite width parallel to the ice edge. Each slab contains an arbitrary (but finite) number of circular ice floes with randomly distributed properties. Ice floes are modeled as thin elastic plates with uniform thickness and finite draught. We consider a directional wave spectrum with harmonic time dependence incident on the MIZ from the open ocean, defined as a continuous superposition of plane waves traveling at different angles. The scattering problem within each slab is then solved using Graf's interaction theory for an arbitrary incident directional plane wave spectrum. Using an appropriate integral representation of the Hankel function of the first kind (see Cincotti et al., 1993), we map the outgoing circular wave field from each floe on the slab boundaries into a directional spectrum of plane waves, which characterizes the slab reflected and transmitted fields. Discretizing the angular spectrum, we can obtain a scattering matrix for each slab. Standard recursive

  4. Steps towards the universal direct current distribution system

    NARCIS (Netherlands)

    Mackay, L.J.

    2018-01-01

    The traditional ac power system is challenged by emerging distributed renewable energy sources and an increase in installed load capacity, e.g., electric vehicles. Most of these new resources use inherently dc as do more and more appliances. This poses the question, if they should still be connected

  5. A wide-range direction neutron spectrometer

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; D'Errico, F.; Hecker, O.; Matzke, M.

    2002-01-01

    A new device is presented which has been developed for measuring the energy and direction of distribution of neutron fluence in fields of broad energy spectra (thermal to 100 MeV) and with a high background of photon, electron and muon radiation. The device was tested in reference fields with different energy and direction distributions of neutron fluence. The direction-integrated fluence spectra agree fairly well with reference spectra. In all cases, the ambient and personal dose equivalent values calculated from measured direction-differential spectra are within 35% of the reference values. Independent measurements of the directional dose equivalent were performed with a directional dose equivalent monitor based on superheated drop detectors

  6. THE MAIN DIRECTIONS OF IMPROVING THE EFFICIENCY OF PRODUCTION, TRANSMISSION AND DISTRIBUTION OF ELECTRICAL ENERGY

    Directory of Open Access Journals (Sweden)

    I. V. Zhezhelenko

    2018-01-01

    Full Text Available The main directions of increase of efficiency of production, transmission and distribution of electric energy have been formulated. The relation between the values of electricity losses during transmission via power grids of different countries and the level of the economies of these countries characterized by the value of gross domestic product at purchasing power parity per capita has been established. In the countries with a gross domestic product at purchasing power parity per capita less than 20 thousand US dollars electricity losses during its transmission via power grids are 1.5–2.5 times more than the ones transmitted via power grids of the industrialized countries where the specified purchasing power parity is in the range of 30.4–54.5 thousand US dollars. In the countries with more developed economies the technical culture of production, transmission and distribution of electricity is higher; the modern control systems of operation modes of electrical networks are used as well as of monitoring and accounting of electricity; also there are solvent and disciplined consumers in such countries as well as clear regulatory framework and tariff regulation system. However, the process of transmission and distribution of electricity is effective if not only low relative losses take place, but the normal (contractual requirements for carrying capacity, quality and reliability of electricity supply are provided. The possibility of analytical determination of the optimum value of reserve capacity of power plants providing the required level of reliability of the power system has been considered.

  7. What's in the input? Frequent frames in child-directed speech offer distributional cues to grammatical categories in Spanish and English.

    Science.gov (United States)

    Weisleder, Adriana; Waxman, Sandra R

    2010-11-01

    Recent analyses have revealed that child-directed speech contains distributional regularities that could, in principle, support young children's discovery of distinct grammatical categories (noun, verb, adjective). In particular, a distributional unit known as the frequent frame appears to be especially informative (Mintz, 2003). However, analyses have focused almost exclusively on the distributional information available in English. Because languages differ considerably in how the grammatical forms are marked within utterances, the scarcity of cross-linguistic evidence represents an unfortunate gap. We therefore advance the developmental evidence by analyzing the distributional information available in frequent frames across two languages (Spanish and English), across sentence positions (phrase medial and phrase final), and across grammatical forms (noun, verb, adjective). We selected six parent-child corpora from the CHILDES database (three English; three Spanish), and analyzed the input when children were aged 2 ; 6 or younger. In each language, frequent frames did indeed offer systematic cues to grammatical category assignment. We also identify differences in the accuracy of these frames across languages, sentences positions and grammatical classes.

  8. Experimental approaches for distribution and behavior of water in PEMFC under flow direction and differential pressure using neutron imaging technique

    International Nuclear Information System (INIS)

    Kim, TaeJoo; Kim, JongRok; Sim, CheulMuu; Lee, SeungWook; Kaviany, Massound; Son, SangYoung; Kim, MooHwan

    2009-01-01

    In this investigation, we prepared a 3-parallel serpentine single PEMFC which has an active area of 25 cm 2 and a flow channel cross section of 1x1 mm. Distribution and transport of water in an operating PEMFC were observed by varying the flow directions (co-current and counter-current) in each channel and the differential pressures (100, 200, 300 kPa) applied between the anode and cathode channels. This investigation was performed at the neutron imaging facility at the NIST of which the collimation ratio and neutron fluence rate are 600, 7.2x10 6 n/s/cm 2 , respectively. Neutron image was continuously recorded by an amorphous silicon flat panel detector every 1 s during the operation of the fuel cell. It has been observed that the differential pressure affects the total amount of water produced while the flow direction affects the spatial distribution of water when the neutron images were analyzed for several different operating conditions. More specifically, the amount of water production in the fuel cell increased as the partial pressure increases at a given current density and the water production was more uniform for the counter current than the co-current case. It is shown that the neutron imaging technique is a powerful tool to visualize the PEMFC. The information on the water distribution and behavior at an operating PEMFC helps improve the efficiency of PEMFC.

  9. The effect of the flow direction inside the header on two-phase flow distribution in parallel vertical channels

    International Nuclear Information System (INIS)

    Marchitto, A.; Fossa, M.; Guglielmini, G.

    2012-01-01

    Uniform fluid distribution is essential for efficient operation of chemical-processing equipment such as contactors, reactors, mixers, burners and in most refrigeration equipment, where two phases are acting together. To obtain optimum distribution, proper consideration must be given to flow behaviour in the distributor, flow conditions upstream and downstream of the distributor, and the distribution requirements (fluid or phase) of the equipment. Even though the principles of single phase distribution have been well developed for more than three decades, they are frequently not taken in the right account by equipment designers when a mixture is present, and a significant fraction of process equipment consequently suffers from maldistribution. The experimental investigation presented in this paper is aimed at understanding the main mechanisms which drive the flow distribution inside a two-phase horizontal header in order to design improved distributors and to optimise the flow distribution inside compact heat exchanger. Experimentation was devoted to establish the influence of the inlet conditions and of the channel/distributor geometry on the phase/mass distribution into parallel vertical channels. The study is carried out with air–water mixtures and it is based on the measurement of component flow rates in individual channels and on pressure drops across the distributor. The effects of the operating conditions, the header geometry and the inlet port nozzle were investigated in the ranges of liquid and gas superficial velocities of 0.2–1.2 and 1.5–16.5 m/s, respectively. In order to control the main flow direction inside the header, different fitting devices were tested; the insertion of a co-axial, multi-hole distributor inside the header has confirmed the possibility of greatly improving the liquid and gas flow distribution by the proper selection of position, diameter and number of the flow openings between the supplying distributor and the system of

  10. Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS)

    NARCIS (Netherlands)

    Butler, J.J.; Park, H.; Barnes, P.Y.; Early, E.A.; Eijk-Olij, C. van; Zoutman, A.E.; Buller-Leeuwen, S. van; Groote Schaarsberg, J.

    2002-01-01

    The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those

  11. When Meaning Is Not Enough: Distributional and Semantic Cues to Word Categorization in Child Directed Speech.

    Science.gov (United States)

    Feijoo, Sara; Muñoz, Carmen; Amadó, Anna; Serrat, Elisabet

    2017-01-01

    One of the most important tasks in first language development is assigning words to their grammatical category. The Semantic Bootstrapping Hypothesis postulates that, in order to accomplish this task, children are guided by a neat correspondence between semantic and grammatical categories, since nouns typically refer to objects and verbs to actions. It is this correspondence that guides children's initial word categorization. Other approaches, on the other hand, suggest that children might make use of distributional cues and word contexts to accomplish the word categorization task. According to such approaches, the Semantic Bootstrapping assumption offers an important limitation, as it might not be true that all the nouns that children hear refer to specific objects or people. In order to explore that, we carried out two studies based on analyses of children's linguistic input. We analyzed child-directed speech addressed to four children under the age of 2;6, taken from the CHILDES database. The corpora were selected from the Manchester corpus. The corpora from the four selected children contained a total of 10,681 word types and 364,196 word tokens. In our first study, discriminant analyses were performed using semantic cues alone. The results show that many of the nouns found in parents' speech do not relate to specific objects and that semantic information alone might not be sufficient for successful word categorization. Given that there must be an additional source of information which, alongside with semantics, might assist young learners in word categorization, our second study explores the availability of both distributional and semantic cues in child-directed speech. Our results confirm that this combination might yield better results for word categorization. These results are in line with theories that suggest the need for an integration of multiple cues from different sources in language development.

  12. Review of Congestion Management Methods for Distribution Networks with High Penetration of Distributed Energy Resources

    DEFF Research Database (Denmark)

    Huang, Shaojun; Wu, Qiuwei; Liu, Zhaoxi

    2014-01-01

    This paper reviews the existing congestion management methods for distribution networks with high penetration of DERs documented in the recent research literatures. The congestion management methods for distribution networks reviewed can be grouped into two categories – market methods and direct...... control methods. The market methods consist of dynamic tariff, distribution capacity market, shadow price and flexible service market. The direct control methods are comprised of network reconfiguration, reactive power control and active power control. Based on the review of the existing methods...

  13. Monitoring Distributed Real-Time Systems: A Survey and Future Directions

    Science.gov (United States)

    Goodloe, Alwyn E.; Pike, Lee

    2010-01-01

    Runtime monitors have been proposed as a means to increase the reliability of safety-critical systems. In particular, this report addresses runtime monitors for distributed hard real-time systems. This class of systems has had little attention from the monitoring community. The need for monitors is shown by discussing examples of avionic systems failure. We survey related work in the field of runtime monitoring. Several potential monitoring architectures for distributed real-time systems are presented along with a discussion of how they might be used to monitor properties of interest.

  14. Effect of feed flow pattern on the distribution of permeate fluxes in desalination by direct contact membrane distillation

    KAUST Repository

    Soukane, Sofiane

    2017-05-31

    The current study aims to highlight the effect of flow pattern on the variations of permeate fluxes over the membrane surface during desalination in a direct contact membrane distillation (DCMD) flat module. To do so, a three dimensional (3D) Computational Fluid Dynamics (CFD) model with embedded pore scale calculations is implemented to predict flow, heat and mass transfer in the DCMD module. Model validation is carried out in terms of average permeate fluxes with experimental data of seawater desalination using two commercially available PTFE membranes. Average permeate fluxes agree within 6% and less with experimental values without fitting parameters. Simulation results show that the distribution of permeate fluxes and seawater salinity over the membrane surface are strongly dependent on momentum and heat transport and that temperature and concentration polarization follow closely the flow distribution. The analysis reveals a drastic effect of recirculation loops and dead zones on module performance and recommendations to improve MD flat module design are drawn consequently.

  15. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1990-01-01

    Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

  16. Data Mining on Distributed Medical Databases: Recent Trends and Future Directions

    Science.gov (United States)

    Atilgan, Yasemin; Dogan, Firat

    As computerization in healthcare services increase, the amount of available digital data is growing at an unprecedented rate and as a result healthcare organizations are much more able to store data than to extract knowledge from it. Today the major challenge is to transform these data into useful information and knowledge. It is important for healthcare organizations to use stored data to improve quality while reducing cost. This paper first investigates the data mining applications on centralized medical databases, and how they are used for diagnostic and population health, then introduces distributed databases. The integration needs and issues of distributed medical databases are described. Finally the paper focuses on data mining studies on distributed medical databases.

  17. Size distribution, directional source contributions and pollution status of PM from Chengdu, China during a long-term sampling campaign.

    Science.gov (United States)

    Shi, Guo-Liang; Tian, Ying-Ze; Ma, Tong; Song, Dan-Lin; Zhou, Lai-Dong; Han, Bo; Feng, Yin-Chang; Russell, Armistead G

    2017-06-01

    Long-term and synchronous monitoring of PM 10 and PM 2.5 was conducted in Chengdu in China from 2007 to 2013. The levels, variations, compositions and size distributions were investigated. The sources were quantified by two-way and three-way receptor models (PMF2, ME2-2way and ME2-3way). Consistent results were found: the primary source categories contributed 63.4% (PMF2), 64.8% (ME2-2way) and 66.8% (ME2-3way) to PM 10 , and contributed 60.9% (PMF2), 65.5% (ME2-2way) and 61.0% (ME2-3way) to PM 2.5 . Secondary sources contributed 31.8% (PMF2), 32.9% (ME2-2way) and 31.7% (ME2-3way) to PM 10 , and 35.0% (PMF2), 33.8% (ME2-2way) and 36.0% (ME2-3way) to PM 2.5 . The size distribution of source categories was estimated better by the ME2-3way method. The three-way model can simultaneously consider chemical species, temporal variability and PM sizes, while a two-way model independently computes datasets of different sizes. A method called source directional apportionment (SDA) was employed to quantify the contributions from various directions for each source category. Crustal dust from east-north-east (ENE) contributed the highest to both PM 10 (12.7%) and PM 2.5 (9.7%) in Chengdu, followed by the crustal dust from south-east (SE) for PM 10 (9.8%) and secondary nitrate & secondary organic carbon from ENE for PM 2.5 (9.6%). Source contributions from different directions are associated with meteorological conditions, source locations and emission patterns during the sampling period. These findings and methods provide useful tools to better understand PM pollution status and to develop effective pollution control strategies. Copyright © 2016. Published by Elsevier B.V.

  18. Experimental analysis of bidirectional reflectance distribution function cross section conversion term in direction cosine space.

    Science.gov (United States)

    Butler, Samuel D; Nauyoks, Stephen E; Marciniak, Michael A

    2015-06-01

    Of the many classes of bidirectional reflectance distribution function (BRDF) models, two popular classes of models are the microfacet model and the linear systems diffraction model. The microfacet model has the benefit of speed and simplicity, as it uses geometric optics approximations, while linear systems theory uses a diffraction approach to compute the BRDF, at the expense of greater computational complexity. In this Letter, nongrazing BRDF measurements of rough and polished surface-reflecting materials at multiple incident angles are scaled by the microfacet cross section conversion term, but in the linear systems direction cosine space, resulting in great alignment of BRDF data at various incident angles in this space. This results in a predictive BRDF model for surface-reflecting materials at nongrazing angles, while avoiding some of the computational complexities in the linear systems diffraction model.

  19. Direct observation of cation distributions of ideal inverse spinel CoFe2O4 nanofibres and correlated magnetic properties

    KAUST Repository

    Zeng, Xue

    2017-04-25

    Low-dimensional spinel ferrites have recently attracted increasing attention because their tunable magnetic properties make them attractive candidates as spin-filtering tunnel barriers in spintronic devices and as magnetic components in artificial multiferroic heterostructures. Although we know that the distribution of cations (Fe3+ and Co2+) in a spinel structure governs its magnetic properties, their distribution in the so-called ideal inverse spinel structure of a ferrite, CoFe2O4, has not yet been imaged with sub-ångstrom resolution. In this work, we fill this gap in evidence by reporting a direct observation of the distribution of cations in an ideal inverse spinel structure of CoFe2O4 nanofibres using aberration-corrected transmission electron microscopy (TEM). The ordering of Co2+ and Fe3+ at the octahedral sites imaged along either [001], [011] or [-112] orientation was identified as 1 : 1, in accordance with the ideal inverse spinel structure. The saturation magnetisation calculated based on the crystal structure as determined from the TEM image is in good agreement with that measured experimentally on the spinel CoFe2O4 nanofibres, further confirming results from TEM.

  20. Capacity of Distribution Feeders for Hosting Distributed Energy Resources

    DEFF Research Database (Denmark)

    Papathanassiou, S.; Hatziargyriou, N.; Anagnostopoulos, P.

    The last two decades have seen an unprecedented development of distributed energy resources (DER) all over the world. Several countries have adopted a variety of support schemes (feed-in tariffs, green certificates, direct subsidies, tax exemptions etc.) so as to promote distributed generation (DG...... standards of the networks. To address this need in a timely and effective manner, simplified methodologies and practical rules of thumbs are often applied to assess the DER hosting capacity of existing distribution networks, avoiding thus detailed and time consuming analytical studies. The scope...

  1. Directional sensitivity of MuSTAnG muon telescope

    Directory of Open Access Journals (Sweden)

    Ganeva Marina

    2013-04-01

    Full Text Available We investigate directional sensitivity of MuSTAnG muon telescope by deriving the distribution of secondary muons, which create the counting rate of telescope, by asymptotic directions of primary protons. This distribution, defined as “directivity function”, allows us to clarify protons appearing from which direction essentially contribute to counting rate of detector. Directivity function has different behavior for the muons falling on the telescope at different zenith and polar angles. Vertical, West, and East fluxes exhibit strong maximums near the asymptotic longitude about 61°, whereas North and South fluxes have larger spread distributions. About 65% of muons, which create the Vertical counting rate of MuSTAnG, are produced by the primary protons, coming in the interval of asymptotic longitudes about (50°, 80°. Using directivity function will allow one to more correctly determine the location of interplanetary disturbances. Analogous analysis, made for other muon detectors, will clarify their directional sensitivities, improving by this the forecasting capability of network of ground-based muon detectors.

  2. Direct laboratory observation of fluid distribution and its influence on acoustic properties of patchy saturated rocks

    Science.gov (United States)

    Lebedev, M.; Clennell, B.; Pervukhina, M.; Shulakova, V.; Mueller, T.; Gurevich, B.

    2009-04-01

    samples (38 mm in diameter, approximately 60 mm long) were dried in oven under reduced pressure. In dynamic saturation experiments, samples were jacketed in the experimental cell, made from transparent for X-radiation material (PMMA). Distillate water was injected into the sample from the one side. Fluid distribution in such "dynamic" experiment: both spatial and time dependant was measured using X-ray Computer Tomograph (CT) with resolution 0.2 x 0.2 x 1 mm3. Velocities (Vp, and Vs) at ultrasonic frequency of 1 MHz, were measured in the direction perpendicular to initial direction of the fluid flow injection. Sample saturation was estimated from the CT results. In "quasi static" experiments samples were saturated during long period of time (over 2 weeks) to achieve uniform distribution of liquid inside the sample. Saturation was determined by measurement of the weight of water fraction. All experiments were performed at laboratory environments at temperature 25 C. Ultrasonic velocities and fluid saturations were measured simultaneously during water injection into sandstone core samples. The experimental results obtained on low-permeability samples show that at low saturation values the velocity-saturation dependence can be described by the Gassmann-Wood relationship. However, with increasing saturation a sharp increase of P-wave velocity is observed, eventually approaching the Gassmann-Hill relationship. We connect the characteristics of the transition behavior of the velocity-saturation relationships to the increasing size of the patches inside the rock sample. In particular, we show that for relatively large fluid injection rate this transition occurs at smaller degrees of saturation as compared with high injection rate. We model the experimental data using the so-called White model (Toms 2007) that assumes fluid patch distribution as a periodic assemblage of concentric spheres. We can observe reasonable agreement between experimental results and theoretical

  3. Hydrodynamic stability and Ti-tracer distribution in low-adiabat OMEGA direct-drive implosions

    Science.gov (United States)

    Joshi, Tirtha R.

    We discuss the hydrodynamic stability of low-adiabat OMEGA direct-drive implosions based on results obtained from simultaneous emission and absorption spectroscopy of a titanium tracer added to the target. The targets were deuterium filled, warm plastic shells of varying thicknesses and filling gas pressures with a submicron Ti-doped tracer layer initially located on the inner surface of the shell. The spectral features from the titanium tracer are observed during the deceleration and stagnation phases of the implosion, and recorded with a time integrated spectrometer (XRS1), streaked crystal spectrometer (SSCA) and three gated, multi-monochromatic X-ray imager (MMI) instruments fielded along quasi-orthogonal lines-of-sight. The time-integrated, streaked and gated data show simultaneous emission and absorption spectral features associated with titanium K-shell line transitions but only the MMI data provides spatially resolved information. The arrays of gated spectrally resolved images recorded with MMI were processed to obtain spatially resolved spectra characteristic of annular contour regions on the image. A multi-zone spectroscopic analysis of the annular spatially resolved spectra permits the extraction of plasma conditions in the core as well as the spatial distribution of tracer atoms. In turn, the titanium atom distribution provides direct evidence of tracer penetration into the core and thus of the hydrodynamic stability of the shell. The observations, timing and analysis indicate that during fuel burning the titanium atoms have migrated deep into the core and thus shell material mixing is likely to impact the rate of nuclear fusion reactions, i.e. burning rate, and the neutron yield of the implosion. We have found that the Ti atom number density decreases towards the center in early deceleration phase, but later in time the trend is just opposite, i.e., it increases towards the center of the implosion core. This is in part a consequence of the convergent

  4. Enhanced distributed energy resource system

    Science.gov (United States)

    Atcitty, Stanley [Albuquerque, NM; Clark, Nancy H [Corrales, NM; Boyes, John D [Albuquerque, NM; Ranade, Satishkumar J [Las Cruces, NM

    2007-07-03

    A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

  5. Distributed routing algorithms to manage power flow in agent-based active distribution network

    NARCIS (Netherlands)

    Nguyen, H.P.; Kling, W.L.; Georgiadis, G.; Papatriantafilou, M.; Anh-Tuan, L.; Bertling, L.

    2010-01-01

    The current transition from passive to active electric distribution networks comes with problems and challenges on bi-directional power flow in the network and the uncertainty in the forecast of power generation from grid-connected renewable and distributed energy sources. The power flow management

  6. Epidemic threshold in directed networks

    Science.gov (United States)

    Li, Cong; Wang, Huijuan; Van Mieghem, Piet

    2013-12-01

    Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ξ as the percentage of unidirectional links. The epidemic threshold τc for the susceptible-infected-susceptible (SIS) epidemic is lower bounded by 1/λ1 in directed networks, where λ1, also called the spectral radius, is the largest eigenvalue of the adjacency matrix. In this work, we propose two algorithms to generate directed networks with a given directionality ξ. The effect of ξ on the spectral radius λ1, principal eigenvector x1, spectral gap (λ1-λ2), and algebraic connectivity μN-1 is studied. Important findings are that the spectral radius λ1 decreases with the directionality ξ, whereas the spectral gap and the algebraic connectivity increase with the directionality ξ. The extent of the decrease of the spectral radius depends on both the degree distribution and the degree-degree correlation ρD. Hence, in directed networks, the epidemic threshold is larger and a random walk converges to its steady state faster than that in undirected networks with the same degree distribution.

  7. Global direct pressures on biodiversity by large-scale metal mining: Spatial distribution and implications for conservation.

    Science.gov (United States)

    Murguía, Diego I; Bringezu, Stefan; Schaldach, Rüdiger

    2016-09-15

    Biodiversity loss is widely recognized as a serious global environmental change process. While large-scale metal mining activities do not belong to the top drivers of such change, these operations exert or may intensify pressures on biodiversity by adversely changing habitats, directly and indirectly, at local and regional scales. So far, analyses of global spatial dynamics of mining and its burden on biodiversity focused on the overlap between mines and protected areas or areas of high value for conservation. However, it is less clear how operating metal mines are globally exerting pressure on zones of different biodiversity richness; a similar gap exists for unmined but known mineral deposits. By using vascular plants' diversity as a proxy to quantify overall biodiversity, this study provides a first examination of the global spatial distribution of mines and deposits for five key metals across different biodiversity zones. The results indicate that mines and deposits are not randomly distributed, but concentrated within intermediate and high diversity zones, especially bauxite and silver. In contrast, iron, gold, and copper mines and deposits are closer to a more proportional distribution while showing a high concentration in the intermediate biodiversity zone. Considering the five metals together, 63% and 61% of available mines and deposits, respectively, are located in intermediate diversity zones, comprising 52% of the global land terrestrial surface. 23% of mines and 20% of ore deposits are located in areas of high plant diversity, covering 17% of the land. 13% of mines and 19% of deposits are in areas of low plant diversity, comprising 31% of the land surface. Thus, there seems to be potential for opening new mines in areas of low biodiversity in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Anisotropy of dark matter velocity distribution

    OpenAIRE

    Nagao, Keiko I.

    2018-01-01

    Direct detection of dark matter with directional sensitivity has the potential to discriminate the dark matter velocity distribution. Especially, it will be suitable to discriminate isotropic distribution from anisotropic one. Analyzing data produced with Monte-Carlo simulation, required conditions for the discrimination is estimated. If energy threshold of detector is optimized, $O(10^3-10^4)$ event number is required to discriminate the anisotropy.

  9. Communication Facilities for Distributed Systems

    Directory of Open Access Journals (Sweden)

    V. Barladeanu

    1997-01-01

    Full Text Available The design of physical networks and communication protocols in Distributed Systems can have a direct impact on system efficiency and reliability. This paper tries to identify efficient mechanisms and paradigms for communication in distributed systems.

  10. A validation of a ray-tracing tool used to generate bi-directional scattering distribution functions for complex fenestration systems

    DEFF Research Database (Denmark)

    McNeil, A.; Jonsson, C.J.; Appelfeld, David

    2013-01-01

    , or daylighting systems. However, such tools require users to provide bi-directional scattering distribution function (BSDF) data that describe the solar-optical performance of the CFS. A free, open-source Radiance tool genBSDF enables users to generate BSDF data for arbitrary CFS. Prior to genBSDF, BSDF data.......We explain the basis and use of the genBSDF tool and validate the tool by comparing results for four different cases to BSDF data produced via alternate methods. This validation demonstrates that BSDFs created with genBSDF are comparable to BSDFs generated analytically using TracePro and by measurement...

  11. Generalized PageRank on Directed Configuration Networks

    NARCIS (Netherlands)

    Chen, Ningyuan; Litvak, Nelli; Olvera-Cravioto, Mariana

    2017-01-01

    Note: formula is not displayed correctly. This paper studies the distribution of a family of rankings, which includes Google’s PageRank, on a directed configuration model. In particular, it is shown that the distribution of the rank of a randomly chosen node in the graph converges in distribution to

  12. Effects of Cardinal Direction on Distribution and Populational Dynamism of Oak Leaf Roller (Tortrix viridana L. on Quercus infectoria Oliv. and Q. libani Lindl.

    Directory of Open Access Journals (Sweden)

    mohammadreza zargaran

    2018-01-01

    was used by employing a 25 m rope, a slope gauge, and a compass to locate the sampling transects. SPSS 18 and the 2×4 factorial split plot in time design were used as the statistical method for studying the effects of various cardinal directions and of oak species on abundance of the European oak leaf roller, and Tukey’s HSD test was employed for comparison of the means. Results and Discussion This pest has a single annual generation and five larval instars. It overwinters, and spends the entire summer, autumn, and winter, as eggs. Eggs are hatch in late March. Larvae pierce buds to enter into and feed inside them, and large larvae can leave buds and start feeding on other buds. The results showed that in both years the number of leaf-roller moth larvae were more on Q. infectoria in comparison to Lebanon oaks and it seems that oak species (Q. infectoria is more preferable for the pest to feed upon than Lebanon oaks. Studying populational changes of the oak leaf-roller moth in the geographical directions proved that for both of the tree species the maximum and the minimum number of larvae were respectively in the east and the west in 2014. In 2015, it also became clear that the highest and the lowest frequency of the larvae were respectively in the south and the north. The obtained results confirmed the influence of wind direction on distribution orientation of leaf-roller moth larvae. The number of oak leaf-roller moth larvae significantly increased in 2015 in comparison to the previous year which can be due to the temperature increase in this year. Conclusions The number of larvae of the European oak leaf roller on Aleppo oak trees was larger compared to Lebanon oak trees both in 2014 and in 2015, which shows this pest prefers Aleppo oak trees over Lebanon oak trees as its food supply. The number of larvae on both oak species in 2015 was considerably larger compared to the previous year, which may have been caused by increased temperatures in 2015. Study of

  13. Hydrothermal industrialization: direct heat development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    A description of hydrothermal resources suitable for direct applications, their associated temperatures, geographic distribution and developable capacity are given. An overview of the hydrothermal direct-heat development infrastructure is presented. Development activity is highlighted by examining known and planned geothermal direct-use applications. Underlying assumptions and results for three studies conducted to determine direct-use market penetration of geothermal energy are discussed.

  14. Distribution planning with reliability options for distributed generation

    International Nuclear Information System (INIS)

    Trebolle, David; Gomez, Tomas; Cossent, Rafael; Frias, Pablo

    2010-01-01

    The promotion of electricity generation from renewable energy sources (RES) and combined heat and power (CHP) has resulted in increasing penetration levels of distributed generation (DG). However, large-scale connection of DG involves profound changes in the operation and planning of electricity distribution networks. Distribution System Operators (DSOs) play a key role since these agents have to provide flexibility to their networks in order to integrate DG. Article 14.7 of EU Electricity Directive states that DSOs should consider DG as an alternative to new network investments. This is a challenging task, particularly under the current regulatory framework where DSOs must be legally and functionally unbundled from other activities in the electricity sector. This paper proposes a market mechanism, referred to as reliability options for distributed generation (RODG), which provides DSOs with an alternative to the investment in new distribution facilities. The mechanism proposed allocates the firm capacity required to DG embedded in the distribution network through a competitive auction. Additionally, RODG make DG partly responsible for reliability and provide DG with incentives for a more efficient operation taking into account the network conditions. (author)

  15. Distribution planning with reliability options for distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    Trebolle, David [Union Fenosa Distribucion, C/Antonio Lopez, 19, 28026 Madrid (Spain); Gomez, Tomas; Cossent, Rafael; Frias, Pablo [Instituto de Investigacion Tecnologica, Escuela Tecnica Superior de Ingenieria, Universidad Pontificia Comillas, C/Quintana 21, 28008 Madrid (Spain)

    2010-02-15

    The promotion of electricity generation from renewable energy sources (RES) and combined heat and power (CHP) has resulted in increasing penetration levels of distributed generation (DG). However, large-scale connection of DG involves profound changes in the operation and planning of electricity distribution networks. Distribution System Operators (DSOs) play a key role since these agents have to provide flexibility to their networks in order to integrate DG. Article 14.7 of EU Electricity Directive states that DSOs should consider DG as an alternative to new network investments. This is a challenging task, particularly under the current regulatory framework where DSOs must be legally and functionally unbundled from other activities in the electricity sector. This paper proposes a market mechanism, referred to as reliability options for distributed generation (RODG), which provides DSOs with an alternative to the investment in new distribution facilities. The mechanism proposed allocates the firm capacity required to DG embedded in the distribution network through a competitive auction. Additionally, RODG make DG partly responsible for reliability and provide DG with incentives for a more efficient operation taking into account the network conditions. (author)

  16. Direct and indirect costs for adverse drug events identified in medical records across care levels, and their distribution among payers.

    Science.gov (United States)

    Natanaelsson, Jennie; Hakkarainen, Katja M; Hägg, Staffan; Andersson Sundell, Karolina; Petzold, Max; Rehnberg, Clas; Jönsson, Anna K; Gyllensten, Hanna

    2017-11-01

    Adverse drug events (ADEs) cause considerable costs in hospitals. However, little is known about costs caused by ADEs outside hospitals, effects on productivity, and how the costs are distributed among payers. To describe the direct and indirect costs caused by ADEs, and their distribution among payers. Furthermore, to describe the distribution of patient out-of-pocket costs and lost productivity caused by ADEs according to socio-economic characteristics. In a random sample of 5025 adults in a Swedish county, prevalence-based costs for ADEs were calculated. Two different methods were used: 1) based on resource use judged to be caused by ADEs, and 2) as costs attributable to ADEs by comparing costs among individuals with ADEs to costs among matched controls. Payers of costs caused by ADEs were identified in medical records among those with ADEs (n = 596), and costs caused to individual patients were described by socio-economic characteristics. Costs for resource use caused by ADEs were €505 per patient with ADEs (95% confidence interval €345-665), of which 38% were indirect costs. Compared to matched controls, the costs attributable to ADEs were €1631, of which €410 were indirect costs. The local health authorities paid 58% of the costs caused by ADEs. Women had higher productivity loss than men (€426 vs. €109, p = 0.018). Out-of-pocket costs displaced a larger proportion of the disposable income among low-income earners than higher income earners (0.7% vs. 0.2%-0.3%). We used two methods to identify costs for ADEs, both identifying indirect costs as an important component of the overall costs for ADEs. Although the largest payers of costs caused by ADEs were the local health authorities responsible for direct costs, employers and patients costs for lost productivity contributed substantially. Our results indicate inequalities in costs caused by ADEs, by sex and income. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Comprehensive evaluation of impacts of distributed generation integration in distribution network

    Science.gov (United States)

    Peng, Sujiang; Zhou, Erbiao; Ji, Fengkun; Cao, Xinhui; Liu, Lingshuang; Liu, Zifa; Wang, Xuyang; Cai, Xiaoyu

    2018-04-01

    All Distributed generation (DG) as the supplement to renewable energy centralized utilization, is becoming the focus of development direction of renewable energy utilization. With the increasing proportion of DG in distribution network, the network power structure, power flow distribution, operation plans and protection are affected to some extent. According to the main impacts of DG, a comprehensive evaluation model of distributed network with DG is proposed in this paper. A comprehensive evaluation index system including 7 aspects, along with their corresponding index calculation method is established for quantitative analysis. The indices under different access capacity of DG in distribution network are calculated based on the IEEE RBTS-Bus 6 system and the evaluation result is calculated by analytic hierarchy process (AHP). The proposed model and method are verified effective and validity through case study.

  18. Algorithm for counting large directed loops

    Energy Technology Data Exchange (ETDEWEB)

    Bianconi, Ginestra [Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Gulbahce, Natali [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, NM 87545 (United States)

    2008-06-06

    We derive a Belief-Propagation algorithm for counting large loops in a directed network. We evaluate the distribution of the number of small loops in a directed random network with given degree sequence. We apply the algorithm to a few characteristic directed networks of various network sizes and loop structures and compare the algorithm with exhaustive counting results when possible. The algorithm is adequate in estimating loop counts for large directed networks and can be used to compare the loop structure of directed networks and their randomized counterparts.

  19. Influence of swirl ratio on fuel distribution and cyclic variation under flash boiling conditions in a spark ignition direct injection gasoline engine

    International Nuclear Information System (INIS)

    Yang, Jie; Xu, Min; Hung, David L.S.; Wu, Qiang; Dong, Xue

    2017-01-01

    Highlights: • Influence of swirl on fuel distribution studied using laser induced fluorescence. • Gradient is sufficient for fuel spatial distribution variation analysis. • Close relation between fuel distribution and flame initiation/development. • Quantitative analysis shows high swirl suppresses variation of fuel distribution. • High order modes capable of identifying the distribution fluctuation patterns. - Abstract: One effective way of suppressing the cycle-to-cycle variation in engine is to design a combustion system that is robust to the root causes of engine variation over the entire engine working process. Flash boiling has been demonstrated as an ideal technique to produce stable fuel spray. But the generation of stable intake flow and fuel mixture remains challenging. In this study, to evaluate the capability of enhanced swirl flow to produce repeatable fuel mixture formation, the fuel distribution inside a single cylinder optical engine under two swirl ratios were measured using laser induced fluorescence technique. The swirl ratio was regulated by a swirl control valve installed in one of the intake ports. A 266 nm wavelength laser sheet from a frequency-quadrupled laser was directed into the optical engine through the quartz liner 15 mm below the tip of the spark plug. The fluorescence signal from the polycyclic aromatic hydrocarbon in gasoline was collected by applying a 320–420 nm band pass filter mounted in front of an intensified charge coupled device camera. Test results show that the in-cylinder fuel distribution is strongly influenced by the swirl ratio. Specifically, under high swirl condition, the fuel is mainly concentrated on the left side of the combustion chamber. While under the low swirl flow, fuel is distributed more randomly over the observing plane. This agrees well with the measurements of the stable flame location. Additionally, the cycle-to-cycle variation of the fuel distribution were analyzed. Results show that well

  20. Direct Energy Marketing Ltd. 1998 annual report

    International Nuclear Information System (INIS)

    1999-01-01

    A corporate profile of Direct Energy Marketing Ltd. was presented for the benefit of shareholders. Direct Energy is responsible for marketing and distributing natural gas to residential, commercial and industrial customers. The company owns physical natural gas reserves that serve as a supply hedge to its growing customer base. The highlights for the natural gas distribution income fund (OPTUS) for 1998 were described. OPTUS acquired WestCastle Energy, adding 38 mmcf/d of natural gas supply. It also amalgamated Channel Lake Petroleum and WestCastle Energy into Direct Energy and created the production division, Direct Energy Resources. It also formed Energy America with Sempra Energy, adding over 160,000 retail customers in Michigan and Ohio. Direct Energy's consolidated financial statements were presented for the benefit of shareholders. These included statements of earnings and deficit, balance sheets, and statements of changes in financial position. Notes to the consolidated financial statements included highlights of significant accounting policies, changes in accounting policies, acquisitions, discontinued operations, and capital assets. tabs., figs

  1. Note on the directional properties of meter-scale gravity waves

    Science.gov (United States)

    Peureux, Charles; Benetazzo, Alvise; Ardhuin, Fabrice

    2018-01-01

    The directional distribution of the energy of young waves is bimodal for frequencies above twice the peak frequency; i.e., their directional distribution exhibits two peaks in different directions and a minimum between. Here we analyze in detail a typical case measured with a peak frequency fp = 0.18 Hz and a wind speed of 10.7 m s-1 using a stereo-video system. This technique allows for the separation of free waves from the spectrum of the sea-surface elevation. The latter indeed tend to reduce the contrast between the two peaks and the background. The directional distribution for a given wavenumber is nearly symmetric, with the angle distance between the two peaks growing with frequency, reaching 150° at 35 times the peak wavenumber kp and increasing up to 45 kp. When considering only free waves, the lobe ratio, the ratio of oblique peak energy density over energy in the wind direction, increases linearly with the non-dimensional wavenumber k/kp, up to a value of 6 at k/kp ≃ 22, and possibly more for shorter components. These observations extend to shorter components' previous measurements, and have important consequences for wave properties sensitive to the directional distribution, such as surface slopes, Stokes drift or microseism sources.

  2. Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS)

    OpenAIRE

    Butler, J.J.; Park, H.; Barnes, P.Y.; Early, E.A.; Eijk-Olij, C. van; Zoutman, A.E.; Buller-Leeuwen, S. van; Groote Schaarsberg, J.

    2002-01-01

    The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those instruments. To assess the ability of laboratories to provide accurate Ultra Violet (UV) diffuse BRDF measurements, a BRDF measurement comparison was initiated by the NASA Total Ozone Mapping Spectrom...

  3. Directional interstitial brachytherapy from simulation to application

    Science.gov (United States)

    Lin, Liyong

    Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

  4. The tensor distribution function.

    Science.gov (United States)

    Leow, A D; Zhu, S; Zhan, L; McMahon, K; de Zubicaray, G I; Meredith, M; Wright, M J; Toga, A W; Thompson, P M

    2009-01-01

    Diffusion weighted magnetic resonance imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of six directions, second-order tensors (represented by three-by-three positive definite matrices) can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g., crossing fiber tracts. Recently, a number of high-angular resolution schemes with more than six gradient directions have been employed to address this issue. In this article, we introduce the tensor distribution function (TDF), a probability function defined on the space of symmetric positive definite matrices. Using the calculus of variations, we solve the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function. Moreover, a tensor orientation distribution function (TOD) may also be derived from the TDF, allowing for the estimation of principal fiber directions and their corresponding eigenvalues.

  5. Cosmic ray intensity distribution in the vertical direction to solar equator plane

    International Nuclear Information System (INIS)

    Nosaka, Toru; Mori, Satoru; Sagisaka, Shuji.

    1983-01-01

    The data of the annual variation of cosmic ray intensity measured by neutron detectors were used to study the distribution of cosmic ray intensity vertical to the solar equator plane and its long term variation. The data used were obtained at Deep River, Kiel, Kerguelen Island, McMurdo, Ottawa, and Mt. Washington. All data showed annual variation. The patterns and degree of variation obtained in northern and southern hemisphere were similar. The summation dial representation of the annual variation and semi-annual variation of cosmic ray was obtained. The inversion of annual variation in 1958 - 1959 and 1968 - 1969 corresponded to the inversion of polarity of solar pole magnetic field. The semi-annual variation showed a complex behavior. The helio-latitudial distribution of cosmic ray intensity was obtained. The asymmetric distribution in relation to the solar equator was observed in the annual variation. The northward gradient of density in 1955 - 1958 and southward gradient in 1959 - 1968 were seen. (Kato, T.)

  6. Matching the quasiparton distribution in a momentum subtraction scheme

    Science.gov (United States)

    Stewart, Iain W.; Zhao, Yong

    2018-03-01

    The quasiparton distribution is a spatial correlation of quarks or gluons along the z direction in a moving nucleon which enables direct lattice calculations of parton distribution functions. It can be defined with a nonperturbative renormalization in a regularization independent momentum subtraction scheme (RI/MOM), which can then be perturbatively related to the collinear parton distribution in the MS ¯ scheme. Here we carry out a direct matching from the RI/MOM scheme for the quasi-PDF to the MS ¯ PDF, determining the non-singlet quark matching coefficient at next-to-leading order in perturbation theory. We find that the RI/MOM matching coefficient is insensitive to the ultraviolet region of convolution integral, exhibits improved perturbative convergence when converting between the quasi-PDF and PDF, and is consistent with a quasi-PDF that vanishes in the unphysical region as the proton momentum Pz→∞ , unlike other schemes. This direct approach therefore has the potential to improve the accuracy for converting quasidistribution lattice calculations to collinear distributions.

  7. Status and future of the direct sales market

    International Nuclear Information System (INIS)

    DuMaresq, P.R.

    1996-01-01

    Three topics of interest concerning the direct purchase of natural gas, were discussed. The three topics were: (1) the Ontario market, past, present and future, along with an analysis of market segmentation, (2) Ontario local distribution companies (LDC) separation, or separating the merchant role from the distribution role, and (3) the status of direct purchase in Alberta. Changes in the natural gas market since deregulation in 1985, were also reviewed. It was noted that today, only a handful of agents, brokers and marketers of natural gas are vying for the market; customers are looking to purchase gas at a price lower than the LDC buy/sell price; and there is pressure for the LDCs to separate the merchant functions from the distribution functions in most of the provinces in Canada. The direct and long term impact of these developments will be to enhance competition among distributors

  8. Direct imaging of dopant distribution in polycrystalline ZnO films

    Czech Academy of Sciences Publication Activity Database

    Lorenzo, F.; Aebersold, A.B.; Morales-Masis, M.; Ledinský, Martin; Escrig, S.; Vetushka, Aliaksi; Alexander, D.T.L.; Hessler-Wyser, A.; Fejfar, Antonín; Hébert, C.; Nicolay, S.; Ballif, C.

    2017-01-01

    Roč. 9, č. 8 (2017), s. 7241-7248 ISSN 1944-8244 R&D Projects: GA ČR GC16-10429J Institutional support: RVO:68378271 Keywords : dopant distribution * film polarity * grain boundaries * NanoSIMS * polycrystalline film * zinc oxide Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 7.504, year: 2016

  9. A joint probability density function of wind speed and direction for wind energy analysis

    International Nuclear Information System (INIS)

    Carta, Jose A.; Ramirez, Penelope; Bueno, Celia

    2008-01-01

    A very flexible joint probability density function of wind speed and direction is presented in this paper for use in wind energy analysis. A method that enables angular-linear distributions to be obtained with specified marginal distributions has been used for this purpose. For the marginal distribution of wind speed we use a singly truncated from below Normal-Weibull mixture distribution. The marginal distribution of wind direction comprises a finite mixture of von Mises distributions. The proposed model is applied in this paper to wind direction and wind speed hourly data recorded at several weather stations located in the Canary Islands (Spain). The suitability of the distributions is judged from the coefficient of determination R 2 . The conclusions reached are that the joint distribution proposed in this paper: (a) can represent unimodal, bimodal and bitangential wind speed frequency distributions, (b) takes into account the frequency of null winds, (c) represents the wind direction regimes in zones with several modes or prevailing wind directions, (d) takes into account the correlation between wind speeds and its directions. It can therefore be used in several tasks involved in the evaluation process of the wind resources available at a potential site. We also conclude that, in the case of the Canary Islands, the proposed model provides better fits in all the cases analysed than those obtained with the models used in the specialised literature on wind energy

  10. SuperB R&D computing program: HTTP direct access to distributed resources

    Science.gov (United States)

    Fella, A.; Bianchi, F.; Ciaschini, V.; Corvo, M.; Delprete, D.; Diacono, D.; Di Simone, A.; Franchini, P.; Donvito, G.; Giacomini, F.; Gianoli, A.; Longo, S.; Luitz, S.; Luppi, E.; Manzali, M.; Pardi, S.; Perez, A.; Rama, M.; Russo, G.; Santeramo, B.; Stroili, R.; Tomassetti, L.

    2012-12-01

    The SuperB asymmetric energy e+e- collider and detector to be built at the newly founded Nicola Cabibbo Lab will provide a uniquely sensitive probe of New Physics in the flavor sector of the Standard Model. Studying minute effects in the heavy quark and heavy lepton sectors requires a data sample of 75 ab-1 and a luminosity target of 1036cm-2s-1. The increasing network performance also in the Wide Area Network environment and the capability to read data remotely with good efficiency are providing new possibilities and opening new scenarios in the data access field. Subjects like data access and data availability in a distributed environment are key points in the definition of the computing model for an HEP experiment like SuperB. R&D efforts in such a field have been brought on during the last year in order to release the Computing Technical Design Report within 2013. WAN direct access to data has been identified as one of the more interesting viable option; robust and reliable protocols as HTTP/WebDAV and xrootd are the subjects of a specific R&D line in a mid-term scenario. In this work we present the R&D results obtained in the study of new data access technologies for typical HEP use cases, focusing on specific protocols such as HTTP and WebDAV in Wide Area Network scenarios. Reports on efficiency, performance and reliability tests performed in a data analysis context have been described. Future R&D plan includes HTTP and xrootd protocols comparison tests, in terms of performance, efficiency, security and features available.

  11. Note on the directional properties of meter-scale gravity waves

    Directory of Open Access Journals (Sweden)

    C. Peureux

    2018-01-01

    Full Text Available The directional distribution of the energy of young waves is bimodal for frequencies above twice the peak frequency; i.e., their directional distribution exhibits two peaks in different directions and a minimum between. Here we analyze in detail a typical case measured with a peak frequency fp = 0.18 Hz and a wind speed of 10.7 m s−1 using a stereo-video system. This technique allows for the separation of free waves from the spectrum of the sea-surface elevation. The latter indeed tend to reduce the contrast between the two peaks and the background. The directional distribution for a given wavenumber is nearly symmetric, with the angle distance between the two peaks growing with frequency, reaching 150° at 35 times the peak wavenumber kp and increasing up to 45 kp. When considering only free waves, the lobe ratio, the ratio of oblique peak energy density over energy in the wind direction, increases linearly with the non-dimensional wavenumber k∕kp, up to a value of 6 at k∕kp ≃ 22, and possibly more for shorter components. These observations extend to shorter components' previous measurements, and have important consequences for wave properties sensitive to the directional distribution, such as surface slopes, Stokes drift or microseism sources.

  12. Intensity-Stabilized Fast-Scanned Direct Absorption Spectroscopy Instrumentation Based on a Distributed Feedback Laser with Detection Sensitivity down to 4 × 10−6

    Directory of Open Access Journals (Sweden)

    Gang Zhao

    2016-09-01

    Full Text Available A novel, intensity-stabilized, fast-scanned, direct absorption spectroscopy (IS-FS-DAS instrumentation, based on a distributed feedback (DFB diode laser, is developed. A fiber-coupled polarization rotator and a fiber-coupled polarizer are used to stabilize the intensity of the laser, which significantly reduces its relative intensity noise (RIN. The influence of white noise is reduced by fast scanning over the spectral feature (at 1 kHz, followed by averaging. By combining these two noise-reducing techniques, it is demonstrated that direct absorption spectroscopy (DAS can be swiftly performed down to a limit of detection (LOD (1σ of 4 × 10−6, which opens up a number of new applications.

  13. Direct Bandgap Group IV Materials

    Science.gov (United States)

    2016-01-21

    AFRL-AFOSR-JP-TR-2017-0049 Direct Bandgap group IV Materials Hung Hsiang Cheng NATIONAL TAIWAN UNIVERSITY Final Report 01/21/2016 DISTRIBUTION A...NAME(S) AND ADDRESS(ES) NATIONAL TAIWAN UNIVERSITY 1 ROOSEVELT RD. SEC. 4 TAIPEI CITY, 10617 TW 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...14. ABSTRACT Direct bandgap group IV materials have been long sought for in both academia and industry for the implementation of photonic devices

  14. Direction selective structural-acoustic coupled radiator

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-04-01

    This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

  15. Distribution function of dark matter

    International Nuclear Information System (INIS)

    Evans, N. Wyn; An, Jin H.

    2006-01-01

    There is good evidence from N-body simulations that the velocity distribution in the outer parts of halos is radially anisotropic, with the kinetic energy in the radial direction roughly equal to the sum of that in the two tangential directions. We provide a simple algorithm to generate such cosmologically important distribution functions. Introducing r E (E), the radius of the largest orbit of a particle with energy E, we show how to write down almost trivially a distribution function of the form f(E,L)=L -1 g(r E ) for any spherical model - including the 'universal' halo density law (Navarro-Frenk-White profile). We in addition give the generic form of the distribution function for any model with a local density power-law index α and anisotropy parameter β and provide limiting forms appropriate for the central parts and envelopes of dark matter halos. From those, we argue that, regardless of the anisotropy, the density falloff at large radii must evolve to ρ∼r -4 or steeper ultimately

  16. Distribution alternatives for a small wine-producer

    Directory of Open Access Journals (Sweden)

    Radka Šperková

    2010-01-01

    Full Text Available Distribution can be defined as a way of goods from producer to consumer. In wine production industry there exist several distribution channels, through which wine is distributed to the final consumer. Aim of this paper is to identify and compare advantages and disadvantages of particular distribution channels for wine sales related to a small wine-producer.Distribution of wine to the final consumer is done through dealers represented by retail chains, specialized wine-shops, hotels, and restaurants. In a smaller scale it is done through internet sales, own outlets and wine auctions. According to the research of Focus agency, Marketing & Social Research, done in 2009, customers buy wine mostly in retail chains and decide on sort and quality of wine directly at the moment of purchase. Selection is based except wine quality also on the shape of the bottle, etiquette, and also cork (consumers explicitly prefer cork, and the screw top rather discourages. Certain part of customers – specifically those, who are more acquainted with wine – buy wine in special wine-shops. The research shows a decrease of direct wine-sales.When using services of independent trade organizations, producers have to control the intensity of commercial activities and knowledge of technical characteristics of products. Small wine producers, though, do not have to use this distribution channel, and can focus only on direct sales. For some small wine producers, specifically those operating in the areas with an extended possibility for wine-tourism, this channel can be more suitable and effective than using retail chains. This way of distribution does not require extensive start-up investments, it is directly dependent on producers own effort, and can be done as a supplementary activity to the main source of income.Regardless the particular choice of a distribution channel by a small wine producer it is necessary to be judged not only from the viewpoint of its advantages and

  17. The limiting distribution of extremal exchange rate yields

    NARCIS (Netherlands)

    M.C.A.B. Hols (Martien); C.G. de Vries (Casper)

    1991-01-01

    textabstractSeveral nonnested fat-tailed distributions have been advocated for modelling exchange rate returns. Instead of directly estimating these nonnested distributions we investigate the extremal distribution of the returns. The advantage is that the parameter which characterizes the amount of

  18. Cost allocation model for distribution networks considering high penetration of distributed energy resources

    DEFF Research Database (Denmark)

    Soares, Tiago; Pereira, Fábio; Morais, Hugo

    2015-01-01

    The high penetration of distributed energy resources (DER) in distribution networks and the competitive environment of electricity markets impose the use of new approaches in several domains. The network cost allocation, traditionally used in transmission networks, should be adapted and used...... in the distribution networks considering the specifications of the connected resources. The main goal is to develop a fairer methodology trying to distribute the distribution network use costs to all players which are using the network in each period. In this paper, a model considering different type of costs (fixed......, losses, and congestion costs) is proposed comprising the use of a large set of DER, namely distributed generation (DG), demand response (DR) of direct load control type, energy storage systems (ESS), and electric vehicles with capability of discharging energy to the network, which is known as vehicle...

  19. Taming astrophysical bias in direct dark matter searches

    NARCIS (Netherlands)

    Pato, M.; Strigari, L.E.; Trotta, R.; Bertone, G.

    2013-01-01

    We explore systematic biases in the identification of dark matter in future direct detection experiments and compare the reconstructed dark matter properties when assuming a self-consistent dark matter distribution function and the standard Maxwellian velocity distribution. We find that the

  20. Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation

    Science.gov (United States)

    Pfeifle, Mark; Ma, Yong-Tao; Jasper, Ahren W.; Harding, Lawrence B.; Hase, William L.; Klippenstein, Stephen J.

    2018-05-01

    Ozonolysis produces chemically activated carbonyl oxides (Criegee intermediates, CIs) that are either stabilized or decompose directly. This branching has an important impact on atmospheric chemistry. Prior theoretical studies have employed statistical models for energy partitioning to the CI arising from dissociation of the initially formed primary ozonide (POZ). Here, we used direct dynamics simulations to explore this partitioning for decomposition of c-C2H4O3, the POZ in ethylene ozonolysis. A priori estimates for the overall stabilization probability were then obtained by coupling the direct dynamics results with master equation simulations. Trajectories were initiated at the concerted cycloreversion transition state, as well as the second transition state of a stepwise dissociation pathway, both leading to a CI (H2COO) and formaldehyde (H2CO). The resulting CI energy distributions were incorporated in master equation simulations of CI decomposition to obtain channel-specific stabilized CI (sCI) yields. Master equation simulations of POZ formation and decomposition, based on new high-level electronic structure calculations, were used to predict yields for the different POZ decomposition channels. A non-negligible contribution of stepwise POZ dissociation was found, and new mechanistic aspects of this pathway were elucidated. By combining the trajectory-based channel-specific sCI yields with the channel branching fractions, an overall sCI yield of (48 ± 5)% was obtained. Non-statistical energy release was shown to measurably affect sCI formation, with statistical models predicting significantly lower overall sCI yields (˜30%). Within the range of experimental literature values (35%-54%), our trajectory-based calculations favor those clustered at the upper end of the spectrum.

  1. Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation.

    Science.gov (United States)

    Pfeifle, Mark; Ma, Yong-Tao; Jasper, Ahren W; Harding, Lawrence B; Hase, William L; Klippenstein, Stephen J

    2018-05-07

    Ozonolysis produces chemically activated carbonyl oxides (Criegee intermediates, CIs) that are either stabilized or decompose directly. This branching has an important impact on atmospheric chemistry. Prior theoretical studies have employed statistical models for energy partitioning to the CI arising from dissociation of the initially formed primary ozonide (POZ). Here, we used direct dynamics simulations to explore this partitioning for decomposition of c-C 2 H 4 O 3 , the POZ in ethylene ozonolysis. A priori estimates for the overall stabilization probability were then obtained by coupling the direct dynamics results with master equation simulations. Trajectories were initiated at the concerted cycloreversion transition state, as well as the second transition state of a stepwise dissociation pathway, both leading to a CI (H 2 COO) and formaldehyde (H 2 CO). The resulting CI energy distributions were incorporated in master equation simulations of CI decomposition to obtain channel-specific stabilized CI (sCI) yields. Master equation simulations of POZ formation and decomposition, based on new high-level electronic structure calculations, were used to predict yields for the different POZ decomposition channels. A non-negligible contribution of stepwise POZ dissociation was found, and new mechanistic aspects of this pathway were elucidated. By combining the trajectory-based channel-specific sCI yields with the channel branching fractions, an overall sCI yield of (48 ± 5)% was obtained. Non-statistical energy release was shown to measurably affect sCI formation, with statistical models predicting significantly lower overall sCI yields (∼30%). Within the range of experimental literature values (35%-54%), our trajectory-based calculations favor those clustered at the upper end of the spectrum.

  2. NEA impactors: what direction to they come from?

    Science.gov (United States)

    Harris, Alan

    2018-04-01

    One might expect, if Earth-crossing NEAs are "thermalized" by prior close scattering encounters with the Earth, that final impact trajectories would be isotropic in direction. But orbital perturbations and other sources of entry and exit to the Earth-crossing zone are faster acting that thermalization, so the actual distribution of impacting orbits is quite anisotropic. I have studied impactor directions by adjusting the orbits of known Earth-crossing PHAs slightly to put them on intersecting orbits and then computed the direction of approach to the Earth. This arguably suffers from "looking under the lamp post", since NEAs are mostly discovered close to the opposition direction, so I also took the distribution of NEA orbits recently derived by Granvik and others and extracted, from a set of 100,000 synthetic orbits they provided, a subset of Earth-crossing PHAs and similarly adjusted them to be intersecting orbits. This should represent an unbiased set of orbits. I then weighted the impact directions by the individual Opik impact probability to obtain a distribution of impact directions weighted by actual impact probabilities. The result was that more than 40% of incoming trajectories clustered within 60 degrees of the opposition direction, and a similar fraction come from within 60 degrees of the solar direction. Thus ~80% of impactors come from only about 1/3 of the sky area, with almost none coming from 60-120 degrees solar elongation. The message is that existing ground-based surveys can hardly be improved upon by greater sky coverage with respect to detecting "death plunge" objects, and even space-based instruments offer very little improvement due to the very low solar elongation of most objects approaching from the solar direction.

  3. Fuzzy barrier distributions

    International Nuclear Information System (INIS)

    Piasecki, E.

    2009-01-01

    Heavy-ion collisions often produce a fusion barrier distribution with structures displaying a fingerprint of couplings to highly collective excitations [1]. Basically the same distribution can be obtained from large-angle quasi-elastic scattering, though here the role of the many weak direct-reaction channels is unclear. For 2 0N e + 9 0Z r we have observed the barrier structures expected for the highly deformed neon projectile, but for 2 0N e + 9 2Z r we find completely smooth distribution (see Fig.1). We find that transfer channels in these systems are of similar strength but single particle excitations are significantly stronger in the latter case. They apparently reduce the 'resolving power' of the quasi-elastic channel, what leads to smeared out, or 'fuzzy' barrier distribution. This is the first case when such a phenomenon has been observed.(author)

  4. Dynamic models for distributed generation resources

    Energy Technology Data Exchange (ETDEWEB)

    Morched, A.S. [BPR Energie, Sherbrooke, PQ (Canada)

    2010-07-01

    Distributed resources can impact the performance of host power systems during both normal and abnormal system conditions. This PowerPoint presentation discussed the use of dynamic models for identifying potential interaction problems between interconnected systems. The models were designed to simulate steady state behaviour as well as transient responses to system disturbances. The distributed generators included directly coupled and electronically coupled generators. The directly coupled generator was driven by wind turbines. Simplified models of grid-side inverters, electronically coupled wind generators and doubly-fed induction generators (DFIGs) were presented. The responses of DFIGs to wind variations were evaluated. Synchronous machine and electronically coupled generator responses were compared. The system model components included load models, generators, protection systems, and system equivalents. Frequency responses to islanding events were reviewed. The study demonstrated that accurate simulations are needed to predict the impact of distributed generation resources on the performance of host systems. Advances in distributed generation technology have outpaced the development of models needed for integration studies. tabs., figs.

  5. Direct production of feruloyl oligosaccharides and hemicellulase inducement and distribution in a newly isolated Aureobasidium pullulans strain.

    Science.gov (United States)

    Yu, Xiao-hong; Gu, Zhen-xin

    2014-02-01

    Studies were carried out to screen and identify strains that are able to directly produce ferulic oligosaccharides (FOs) from wheat bran (WB). The inducement and distribution of hemicellulases from strain 2012, which was identified as a non-melanin secreting strain of Aureobasidium pullulans (A. pullulans), were also determined. In a 60 g/L WB solution, A. pullulans could produce 545 nmol/L FOs, 64.12 IU/mL xylanase and 0.14 IU/mL ferulic acid esterase (FAE). A. pullulans was cultivated in media with WB, glucose, xylose, sucrose, lactose or xylan as the carbon source, and hemicellulases were mainly induced by xylan and WB and inhibited by glucose and sucrose. Xylanase and FAE were mainly present in the culture filtrate, xylosidase in the hyphal filaments and arabinofuranosidase was a membrane-bound enzyme. The yield of FOs was positively correlated to the hemicellulases activity, and significantly positively (P < 0.05) correlated to the xylanase activity (r = 0.992).

  6. Direct Determination of Molecular Weight Distribution of Calf-Thymus DNAs and Study of Their Fragmentation under Ultrasonic and Low-Energy IR Irradiations. A Charge Detection Mass Spectrometry Investigation.

    Science.gov (United States)

    Halim, Mohammad A; Bertorelle, Franck; Doussineau, Tristan; Antoine, Rodolphe

    2018-06-09

    Calf-thymus (CT-DNA) is widely used as binding agent. The commercial samples are known to be "highly polymerized DNA" samples. CT-DNA is known to be fragile in particular upon ultrasonic wave irradiation. Degradation products might have dramatic consequence on its bio-sensing activity, and an accurate determination of the molecular weight distribution and stability of commercial samples is highly demanded. We investigated the sensitivity of charge detection mass spectrometry (CDMS), a single-molecule MS method, both with single-pass and ion trap CDMS ("Benner" trap) modes to the determination of the composition and stability (under multiphoton IR irradiation) of calf-thymus DNAs. We also investigated the changes of molecular weight distributions in the course of sonication by irradiating ultrasonic wave to CT-DNA. We report for the first time, the direct molecular weight (MW) distribution of DNA sodium salt from calf-thymus revealing two populations at high (~10 MDa) and low (~3 MDa) molecular weights. We evidence a transition between the high-MW to the low-MW distribution, confirming that the low-MW distribution results from degradation of CT-DNA. Finally, we report also IRMPD experiments carried out on trapped single-stranded linear DNAs from calf-thymus allowing to extract their activation energy for unimolecular dissociation. We show that single-pass CDMS is a direct, efficient and accurate MS-based approach to determine the composition of calf-thymus DNAs. Furthermore, ion trap CDMS allows us to evaluate the stability (both under multiphoton IR irradiation and in the course of sonication by irradiating ultrasonic wave) of calf-thymus DNAs. This article is protected by copyright. All rights reserved.

  7. Angular distributions in pre-equilibrium reactions

    International Nuclear Information System (INIS)

    Chatterjee, A.; Gupta, S.K.; Bhabha Atomic Research Centre, Bombay

    1982-10-01

    A new model is proposed for calculating angular distributions in preequilibrium reactions. In this model, as in the model of Feshbach et al. the system consisting of target plus projectile initially branches into two sets of states with either no particle in the continuum (multistep compound states) or with at least one particle in the continuum (multistep direct states). The two chains of states are treated independently by solving two sets of master equations. The multistep compound emission is assumed to be isotropic while the angular distribution of the multistep direct emission is described using the fast particle model of Mantzouranis et al. The angular distributions for 14.6 MeV neutrons calculated using this model are found to be in better agreement with the data than the fast particle model. (author)

  8. First Directly Retrieved Global Distribution of Tropospheric Column Ozone from GOME: Comparison with the GEOS-CHEM Model

    Science.gov (United States)

    Liu, Xiong; Chance, Kelly; Sioris, Christopher E.; Kurosu, Thomas P.; Spurr, Robert J. D.; Martin, Randall V.; Fu, Tzung-May; Logan, Jennifer A.; Jacob, Daniel J.; Palmer, Paul I.; hide

    2006-01-01

    We present the first directly retrieved global distribution of tropospheric column ozone from Global Ozone Monitoring Experiment (GOME) ultraviolet measurements during December 1996 to November 1997. The retrievals clearly show signals due to convection, biomass burning, stratospheric influence, pollution, and transport. They are capable of capturing the spatiotemporal evolution of tropospheric column ozone in response to regional or short time-scale events such as the 1997-1998 El Nino event and a 10-20 DU change within a few days. The global distribution of tropospheric column ozone displays the well-known wave-1 pattern in the tropics, nearly zonal bands of enhanced tropospheric column ozone of 36-48 DU at 20degS-30degS during the austral spring and at 25degN-45degN during the boreal spring and summer, low tropospheric column ozone of 33 DU at some northern high-latitudes during the spring. Simulation from a chemical transport model corroborates most of the above structures, with small biases of <+/-5 DU and consistent seasonal cycles in most regions, especially in the southern hemisphere. However, significant positive biases of 5-20 DU occur in some northern tropical and subtropical regions such as the Middle East during summer. Comparison of GOME with monthly-averaged Measurement of Ozone and Water Vapor by Airbus in-service Aircraft (MOZAIC) tropospheric column ozone for these regions usually shows good consistency within 1 a standard deviations and retrieval uncertainties. Some biases can be accounted for by inadequate sensitivity to lower tropospheric ozone, the different spatiotemporal sampling and the spatiotemporal variations in tropospheric column ozone.

  9. Direction of arrival estimation based on information geometry

    NARCIS (Netherlands)

    Coutiño Minguez, M.A.; Pribic, R; Leus, G.J.T.; Dong, Min; Zheng, Thomas Fang

    2016-01-01

    In this paper, a new direction of arrival (DOA) estimation approach is devised using concepts from information geometry (IG). The proposed method uses geodesic distances in the statistical manifold of probability distributions parametrized by their covariance matrix to estimate the direction of

  10. Antiquark distributions in the proton

    International Nuclear Information System (INIS)

    Brooks, M.; Carey, T.; Garvey, G.

    1997-01-01

    This is the final report of a three-year Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The study of quark and antiquark distributions in the nucleon has been a major endeavor in nuclear and particle physics. Results from a recent deep-inelastic scattering experiment suggest the surprising possibility that the up and down antiquark distributions in the proton are not symmetric. A sensitive and direct determination of the antiquark distributions in the proton can be made by comparing the Drell-Yan cross sections on hydrogen versus deuterium targets. The authors have proposed a new experiment (E866) at Fermilab to carry out such measurements. E866 has been taking data since September 1996. Preliminary results show that the apparatus is working very well. The authors anticipate having seven months of beam in 1997, which would allow them to achieve the sensitivities for a definitive measurement of flavor symmetry of sea quarks in the proton

  11. Dark matter direct detection with non-Maxwellian velocity structure

    International Nuclear Information System (INIS)

    Kuhlen, Michael; Weiner, Neal; Diemand, Jürg; Moore, Ben; Potter, Doug; Stadel, Joachim; Madau, Piero; Zemp, Marcel

    2010-01-01

    The velocity distribution function of dark matter particles is expected to show significant departures from a Maxwell-Boltzmann distribution. This can have profound effects on the predicted dark matter - nucleon scattering rates in direct detection experiments, especially for dark matter models in which the scattering is sensitive to the high velocity tail of the distribution, such as inelastic dark matter (iDM) or light (few GeV) dark matter (LDM), and for experiments that require high energy recoil events, such as many directionally sensitive experiments. Here we determine the velocity distribution functions from two of the highest resolution numerical simulations of Galactic dark matter structure (Via Lactea II and GHALO), and study the effects for these scenarios. For directional detection, we find that the observed departures from Maxwell-Boltzmann increase the contrast of the signal and change the typical direction of incoming DM particles. For iDM, the expected signals at direct detection experiments are changed dramatically: the annual modulation can be enhanced by more than a factor two, and the relative rates of DAMA compared to CDMS can change by an order of magnitude, while those compared to CRESST can change by a factor of two. The spectrum of the signal can also change dramatically, with many features arising due to substructure. For LDM the spectral effects are smaller, but changes do arise that improve the compatibility with existing experiments. We find that the phase of the modulation can depend upon energy, which would help discriminate against background should it be found

  12. Problem-Based Learning and Problem-Solving Tools: Synthesis and Direction for Distributed Education Environments.

    Science.gov (United States)

    Friedman, Robert S.; Deek, Fadi P.

    2002-01-01

    Discusses how the design and implementation of problem-solving tools used in programming instruction are complementary with both the theories of problem-based learning (PBL), including constructivism, and the practices of distributed education environments. Examines how combining PBL, Web-based distributed education, and a problem-solving…

  13. Mean-field level analysis of epidemics in directed networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiazeng [School of Mathematical Sciences, Peking University, Beijing 100871 (China); Liu, Zengrong [Mathematics Department, Shanghai University, Shanghai 200444 (China)], E-mail: wangjiazen@yahoo.com.cn, E-mail: zrongliu@online.sh.cn

    2009-09-04

    The susceptible-infected-removed spreading model in a directed graph is studied. The mean-field level rate equations are built with the degree-degree connectivity correlation element and the (in, out)-degree distribution. And the outbreak threshold is obtained analytically-it is determined by the combination of connectivity probability and the degree distribution. Furthermore, the methods of calculating the degree-degree correlations in directed networks are presented. The numerical results of the discrete epidemic processes in networks verify our analyses.

  14. Mean-field level analysis of epidemics in directed networks

    International Nuclear Information System (INIS)

    Wang, Jiazeng; Liu, Zengrong

    2009-01-01

    The susceptible-infected-removed spreading model in a directed graph is studied. The mean-field level rate equations are built with the degree-degree connectivity correlation element and the (in, out)-degree distribution. And the outbreak threshold is obtained analytically-it is determined by the combination of connectivity probability and the degree distribution. Furthermore, the methods of calculating the degree-degree correlations in directed networks are presented. The numerical results of the discrete epidemic processes in networks verify our analyses.

  15. The energy distribution of electrons in radio jets

    Science.gov (United States)

    Tsouros, Alexandros; Kylafis, Nikolaos D.

    2017-07-01

    Context. Black-hole and neutron-star X-ray binaries exhibit compact radio jets, when they are in the so called quiescent, hard, or hard intermediate states. The radio spectrum in these states is flat to slightly inverted, I.e., the spectral index of the observed flux density is in the range 0 ≲ α ≲ 0.5. It is widely accepted that the energy distribution of the electrons, in the rest frame of the jet, is a power law with index in the range 3 ≲ p ≲ 5. Aims: Contrary to what our thinking was decades ago, now we know that the jets originate in the hot, inner flow around black holes and neutron stars. So it is worth investigating the radio spectrum that is emitted by a thermal jet as a function of direction. Methods: As an example, we consider a parabolic jet and, with the assumption of flux freezing, we compute the emitted spectrum in all directions, from radio to near infrared, using either a thermal distribution of electrons or a power-law one. Results: We have found that parabolic jets with a thermal distribution of electrons give also flat to slightly inverted spectra. In particular, for directions along the jet (θ = 0), both distributions of electron energies give α = 0 ± 0.01. The index α increases as the viewing angle θ increases and for directions perpendicular to the jet (θ = π/ 2), the thermal distribution gives α = 0.40 ± 0.05, while the power-law distribution gives α = 0.20 ± 0.05. The break frequency νb, which marks the transition from partially optically thick to optically thin synchrotron emission, is comparable for the power-law and the thermal distributions. Conclusions: Contrary to common belief, it is not necessary to invoke a power-law energy distribution of the electrons in a jet to explain its flat to slightly inverted radio spectrum. A relativistic Maxwellian produces similar radio spectra. Thus, the jet may be the widely invoked "corona" around black holes in X-ray binaries.

  16. Optimized constitutive distributions visualized by lamina formulas

    DEFF Research Database (Denmark)

    Pedersen, Pauli; Pedersen, Niels Leergaard

    2017-01-01

    For optimal design most parameters may be classified in size, shape, and topology, such as simple density variables and parameters for surface description. Density and surface can be rather directly visualized. Extending the design to material design in sense of design of distributions of constit......For optimal design most parameters may be classified in size, shape, and topology, such as simple density variables and parameters for surface description. Density and surface can be rather directly visualized. Extending the design to material design in sense of design of distributions...

  17. Distributed Fault-Tolerant Quality Of Service Routing in Hybrid Directional Wireless Networks

    National Research Council Canada - National Science Library

    Llewellyn, II, Larry C

    2007-01-01

    This thesis presents a distributed fault-tolerant routing protocol (EFDCB) for QoS supporting hybrid mobile ad hoc networks with the aim of mitigating QoS disruption time when network failures occur...

  18. Direct detection of neutral metal atoms in electron-stimulated desorption: Al from CH3O/Al(111) - velocity distribution and absolute yield

    International Nuclear Information System (INIS)

    Whitten, J.E.; Young, C.E.; Pellin, M.J.; Gruen, D.M.; Jones, P.L.

    1994-01-01

    Electron-stimulated desorption of neutral aluminum from the system CH 3 O/Al(111) has been directly monitored via quasiresonant photoionization with 193 nm excimer laser light and confirmed by two-step resonant ionization, utilizing the Al 3d 2 D manifold. Velocity distribution measurements for the neutral Al peak at ∼ 800 m/s for 1 keV incident electron energy. An absolute yield of 3.2 x 10 -6 Al atoms/electron was determined by comparison with sputtering measurements in the same apparatus. This is the first observation of electron-stimulated metal desorption from adsorbate-covered metallic surfaces

  19. Patterns of postural deformity in non-ambulant people with cerebral palsy: what is the relationship between the direction of scoliosis, direction of pelvic obliquity, direction of windswept hip deformity and side of hip dislocation?

    Science.gov (United States)

    Porter, David; Michael, Shona; Kirkwood, Craig

    2007-12-01

    To investigate: (a) associations between the direction of scoliosis, direction of pelvic obliquity, direction of windswept deformity and side of hip subluxation/ dislocation in non-ambulant people with cerebral palsy; and (b) the lateral distribution of these postural asymmetries. Cross-sectional observational study. Posture management services in three centres in the UK. Non-ambulant people at level five on the gross motor function classification system for cerebral palsy. Direction of pelvic obliquity and lateral spinal curvature determined from physical examination, direction of windswept hip deformity derived from range of hip abduction/adduction, and presence/side of unilateral hip subluxation defined by hip migration percentage. A total of 747 participants were included in the study, aged 6-80 years (median 18 years 10 months). Associations between the direction of scoliosis and direction of pelvic obliquity, and between the direction of windswept hip deformity and side hip subluxation/dislocation were confirmed. A significant association was also seen between the direction of scoliosis and the direction of the windswept hip deformity (P<0.001) such that the convexity of the lateral spinal curve was more likely to be opposite to the direction of windsweeping. Furthermore, significantly more windswept deformities to the right (P=0.007), hips subluxed on the left (P=0.002) and lateral lumbar/lower thoracic spinal curves convex to the left (P=0.03) were observed. The individual asymmetrical postural deformities are not unrelated in terms of direction and not equally distributed to the left/right. A pattern of postural deformity was observed.

  20. Limitations of the Porter-Thomas distribution

    Science.gov (United States)

    Weidenmüller, Hans A.

    2017-12-01

    Data on the distribution of reduced partial neutron widths and on the distribution of total gamma decay widths disagree with the Porter-Thomas distribution (PTD) for reduced partial widths or with predictions of the statistical model. We recall why the disagreement is important: The PTD is a direct consequence of the orthogonal invariance of the Gaussian Orthogonal Ensemble (GOE) of random matrices. The disagreement is reviewed. Two possible causes for violation of orthogonal invariance of the GOE are discussed, and their consequences explored. The disagreement of the distribution of total gamma decay widths with theoretical predictions cannot be blamed on the statistical model.

  1. Laser direct writing using submicron-diameter fibers.

    Science.gov (United States)

    Tian, Feng; Yang, Guoguang; Bai, Jian; Xu, Jianfeng; Hou, Changlun; Liang, Yiyong; Wang, Kaiwei

    2009-10-26

    In this paper, a novel direct writing technique using submicron-diameter fibers is presented. The submicron-diameter fiber probe serves as a tightly confined point source and it adopts micro touch mode in the process of writing. The energy distribution of direct writing model is analyzed by Three-Dimension Finite-Difference Time-Domain method. Experiments demonstrate that submicron-diameter fiber direct writing has some advantages: simple process, 350-nm-resolution (lower than 442-nm-wavelength), large writing area, and controllable width of lines. In addition, by altering writing direction of lines, complex submicron patterns can be fabricated.

  2. Gauge-invariant area distributions for semiclassical magnetotransport through ballistic nanostructures

    International Nuclear Information System (INIS)

    Wirtz, L.; Yang, Xiazhou; Burgdoerfer, J.E.

    1996-01-01

    Within the semiclassical theory of magnetotransport, conductance fluctuations in ballistic cavities are determined by distribution functions of directed areas enclose by classical paths. The authors calculate gauge invariant areas which can be visualized as closure of areas by adding a virtual path to the real path connecting the leads. Gauge invariance of the resulting area distribution is found to be important for geometry-sensitive non-universal properties of transport. The authors show that in the presence of direct paths both the area distribution and the two-point pair distribution function for areas of trajectories contribute. Comparison with recent data by Marcus et al. for a stadium-shaped nanostructure is made

  3. Use of indicating material for direct indication of neutrons distributed photographically

    International Nuclear Information System (INIS)

    Weiss, A.K.; Fico, S.S.

    1977-01-01

    Electrons distributed photographically can be clearly indicated by a layer, which contains a crystalline polyacetylene connection. An indicating material which contained a short chain alkylester of diindiacid, a polyacetylene polyacidic alkylamide, a polyacetylene amine salt or a diindiolurethane proved particularly suitable. The materials are used in neutron radiography. The construction of the layers is described in detail. 11 extensive examples explain possible variations. (UWI) [de

  4. Field distribution in a coaxial electrostatic wiggler

    Directory of Open Access Journals (Sweden)

    Shi-Chang Zhang

    2010-09-01

    Full Text Available The field distribution in a coaxial electrostatic wiggler corresponds to the special solution of a Laplace equation in a cylindrical coordinate system with a boundary value problem of sinusoidal ripples. This paper is devoted to the physical and mathematical treatment for an analytical solution of the field distribution in the coaxial electrostatic wiggler. The explicit expression of the solution indicates that the field distribution in the coaxial electrostatic wiggler varies according to a periodic function in the longitudinal direction, and is related to the first and second kinds of modified Bessel functions in the radial direction, respectively. Comparison shows excellent agreement between the analytical formula and the computer simulation technology (CST results. The physical application of the considered system and its analytical solution are discussed.

  5. Progress on Protection Strategies to Mitigate the Impact of Renewable Distributed Generation on Distribution Systems

    Directory of Open Access Journals (Sweden)

    Mohamad Norshahrani

    2017-11-01

    Full Text Available The benefits of distributed generation (DG based on renewable energy sources leads to its high integration in the distribution network (DN. Despite its well-known benefits, mainly in improving the distribution system reliability and security, there are challenges encountered from a protection system perspective. Traditionally, the design and operation of the protection system are based on a unidirectional power flow in the distribution network. However, the integration of distributed generation causes multidirectional power flows in the system. Therefore, the existing protection systems require some improvement or modification to address this new feature. Various protection strategies for distribution system have been proposed so that the benefits of distributed generation can be fully utilized. This paper reviews the current progress in protection strategies to mitigate the impact of distributed generation in the distribution network. In general, the reviewed strategies in this paper are divided into: (1 conventional protection systems and (2 modifications of the protection systems. A comparative study is presented in terms of the respective benefits, shortcomings and implementation cost. Future directions for research in this area are also presented.

  6. Ripple distribution for nonlinear fiber-optic channels.

    Science.gov (United States)

    Sorokina, Mariia; Sygletos, Stylianos; Turitsyn, Sergei

    2017-02-06

    We demonstrate data rates above the threshold imposed by nonlinearity on conventional optical signals by applying novel probability distribution, which we call ripple distribution, adapted to the properties of the fiber channel. Our results offer a new direction for signal coding, modulation and practical nonlinear distortions compensation algorithms.

  7. A Review of Multivariate Distributions for Count Data Derived from the Poisson Distribution.

    Science.gov (United States)

    Inouye, David; Yang, Eunho; Allen, Genevera; Ravikumar, Pradeep

    2017-01-01

    The Poisson distribution has been widely studied and used for modeling univariate count-valued data. Multivariate generalizations of the Poisson distribution that permit dependencies, however, have been far less popular. Yet, real-world high-dimensional count-valued data found in word counts, genomics, and crime statistics, for example, exhibit rich dependencies, and motivate the need for multivariate distributions that can appropriately model this data. We review multivariate distributions derived from the univariate Poisson, categorizing these models into three main classes: 1) where the marginal distributions are Poisson, 2) where the joint distribution is a mixture of independent multivariate Poisson distributions, and 3) where the node-conditional distributions are derived from the Poisson. We discuss the development of multiple instances of these classes and compare the models in terms of interpretability and theory. Then, we empirically compare multiple models from each class on three real-world datasets that have varying data characteristics from different domains, namely traffic accident data, biological next generation sequencing data, and text data. These empirical experiments develop intuition about the comparative advantages and disadvantages of each class of multivariate distribution that was derived from the Poisson. Finally, we suggest new research directions as explored in the subsequent discussion section.

  8. ESR spectroscopy and electron distribution

    International Nuclear Information System (INIS)

    Davies, A.G.

    1997-01-01

    EPR spectroscopy can map out the electron distribution in a molecule, in much the same way as proton NMR spectroscopy can map out the proton distribution, and it provides some of the most direct evidence for the principal concepts underlying the electronic theory of organic structure and mechanism. This is illustrated for phenomena of conjugation, hyper-conjugation, substituent effects in annulenes, Hueckel theory, ring strain, the Mills-Nixon effect, and ion pairing. (author)

  9. Design winds during ice storm as a function of direction for transmission lines

    Energy Technology Data Exchange (ETDEWEB)

    Chouinard, L. [McGill Univ., Montreal, PQ (Canada); Feknous, N. [SNC-Lavalin, Montreal, PQ (Canada); Sabourin, G. [Hydro-Quebec, Montreal, PQ (Canada)

    2005-07-01

    The effects of wind directionality are important considerations in the design of electric transmission lines. A procedure for the estimation of the probability distribution function of maximum wind speed as a function of direction was proposed. The procedure was applied to the sample of annual maximum wind speeds using the Gumbal distribution method and then used to estimate the maximum wind speed as a function of direction for the sample of maximum annual wind speeds, and maximum annual wind speeds during ice storms at 22 locations throughout Quebec. Wind direction obtained from the meteorological stations was recorded in 10 degrees sectors. The data set was used to obtain maximum wind speed for each year in each of 36 sectors. The joint probability distribution function was obtained by assuming that extreme distribution for non-directional winds was common to all directions during a season or period, as well as by assuming independence between wind speed and wind direction during a storm pattern. Structural effects were obtained by integrating the joint probability distribution with design equations. Results were then presented in the form of a ratio relative to the reference wind speed for each location. The procedure was demonstrated using a meteorological data set as well as glaze ice data from Quebec City, and covered a period of 30 years. Results indicated that a reduction factor of 25 per cent can be achieved on ice accumulations when overhead lines are directed parallel to dominant winds. It was concluded that the method will represent significant savings in the design and up-grading of existing lines. Further research will be conducted to address issues related to regional criteria and local adjustments for topographical features. 7 refs., 4 figs.

  10. Flow distribution in the inlet plenum of steam generator

    International Nuclear Information System (INIS)

    Khadamakar, H.P.; Patwardhan, A.W.; Padmakumar, G.; Vaidyanathan, G.

    2011-01-01

    Highlights: → Various flow distribution devices have been studied to make the flow distribution uniform in axial as well as tangential direction. → Experiments were performed using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV). → CFD modeling has been carried out to give more insights. → Various flow distribution devices have been compared. - Abstract: The flow distribution in a 1/5th and 1/8th scale models of inlet plenum of steam generator (SG) has been studied by a combination of experiments and Computational Fluid Dynamics (CFD) simulations. The distribution of liquid sodium in the inlet plenum of the SG strongly affects the thermal as well as mechanical performance of the steam generator. Various flow distribution devices have been used to make the flow distribution uniform in axial as well as tangential direction in the window region. Experiments have been conducted to measure the radial velocity distribution using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV) under a variety of conditions. CFD modeling has been carried out for various configurations to give more insight into the flow distribution phenomena. The various flow distribution devices have been compared on the basis of a non-uniformity index parameter.

  11. Strategic Directions in Object-Oriented Programming

    NARCIS (Netherlands)

    Aksit, Mehmet; Guerroui, Rachid

    1996-01-01

    This paper has provided an overview of the field of object-oriented programming. After presenting a historical perspective and some major achievements in the field, four research directions were introduced: technologies integration, software components, distributed programming, and new paradigms. In

  12. Direct simulation of groundwater transit-time distributions using the reservoir theory

    Science.gov (United States)

    Etcheverry, David; Perrochet, Pierre

    Groundwater transit times are of interest for the management of water resources, assessment of pollution from non-point sources, and quantitative dating of groundwaters by the use of environmental isotopes. The age of water is the time water has spent in an aquifer since it has entered the system, whereas the transit time is the age of water as it exits the system. Water at the outlet of an aquifer is a mixture of water elements with different transit times, as a consequence of the different flow-line lengths. In this paper, transit-time distributions are calculated by coupling two existing methods, the reservoir theory and a recent age-simulation method. Based on the derivation of the cumulative age distribution over the whole domain, the approach accounts for the whole hydrogeological framework. The method is tested using an analytical example and its applicability illustrated for a regional layered aquifer. Results show the asymmetry and multimodality of the transit-time distribution even in advection-only conditions, due to the aquifer geometry and to the velocity-field heterogeneity. Résumé Les temps de transit des eaux souterraines sont intéressants à connaître pour gérer l'évaluation des ressources en eau dans le cas de pollution à partir de sources non ponctuelles, et aussi pour dater quantitativement les eaux souterraines au moyen des isotopes du milieu. L'âge de l'eau est le temps qu'elle a passé dans un aquifère depuis qu'elle est entrée dans le système, alors que le temps de transit est l'âge de l'eau au moment où elle quitte le système. L'eau à la sortie d'un aquifère est un mélange d'eaux possédant différents temps de transit, du fait des longueurs différentes des lignes de courant suivies. Dans ce papier, les distributions des temps de transit sont calculées en couplant deux méthodes, la théorie du réservoir et une méthode récente de simulation des âges. Basée sur la dérivation de la distribution cumulées des âges sur

  13. Direct observation of the current distribution in thin superconducting strips using magneto-optic imaging

    International Nuclear Information System (INIS)

    Johansen, T.H.; Baziljevich, M.; Bratsberg, H.; Galperin, Y.; Lindelof, P.E.; Shen, Y.; Vase, P.

    1996-01-01

    Magneto-optic imaging was used for a detailed study of the flux and current distribution of a long thin strip of YBa 2 Cu 3 O 7-δ placed in a perpendicular external magnetic field. The inverse magnetic problem, i.e., that of deriving from a field map the underlying current distribution, is formulated and solved for the strip geometry. Applying the inversion to the magneto-optically found field map we find on a model-independent basis the current distribution across the strip to be in remarkable agreement with the profile predicted by the Bean model. The paper also presents results on the behavior of the Bi-doped YIG film with in-plane anisotropy which we use as field indicator, explaining why previous measurements of flux density profiles have displayed surprisingly large deviations from the expected behavior. copyright 1996 The American Physical Society

  14. Method of forecasting power distribution

    International Nuclear Information System (INIS)

    Kaneto, Kunikazu.

    1981-01-01

    Purpose: To obtain forecasting results at high accuracy by reflecting the signals from neutron detectors disposed in the reactor core on the forecasting results. Method: An on-line computer transfers, to a simulator, those process data such as temperature and flow rate for coolants in each of the sections and various measuring signals such as control rod positions from the nuclear reactor. The simulator calculates the present power distribution before the control operation. The signals from the neutron detectors at each of the positions in the reactor core are estimated from the power distribution and errors are determined based on the estimated values and the measured values to determine the smooth error distribution in the axial direction. Then, input conditions at the time to be forecast are set by a data setter. The simulator calculates the forecast power distribution after the control operation based on the set conditions. The forecast power distribution is corrected using the error distribution. (Yoshino, Y.)

  15. Direct Spanish Investments in Latin America

    Directory of Open Access Journals (Sweden)

    Alfredo Arahuetes García

    1995-11-01

    Full Text Available In the period 1981-1992, the international flow of direct investments witnessed significant changes which affected their magnitude, geographical orientation, sectorial distribution, forms of investment and sources of financing. This happened in such a way that traditional distribution among industrialized and developing countries was modified as was the capacity for attraction of the different areas in development. In this sense, the main contrast could be seen in the growing importance of East and South East Asia and the decline of Latin American countries which traditionally have been the largest receivers of direct investments within the group of developing countries. The expansive phase of direct investments begun in 1986 threatened to exclude Latin American countries but the establishment of a new framework for the treatment of the problem of external debt -the Brady Plan-, the change in the context of theinternational economy in 1990 and the stability and economic growth of the countries of the region favoured, without a doubt, the recovery of the capacity for attraction for new flows of direct investments regarding Latin American countries.In this way, Latin America registered once again a growing participation in the international flow of direct investments. The evolution of direct Spanish investment in Latin America followed a path similar to that of wider international flows and, after the intense absorption of the first years of the Eighties, the rest of the decade registered a discreet attraction for investors which only began to change course from 1989 onwards with the reestablishment of the new phase of the economic cycle in the countries of the region.

  16. Impacts on the Voltage Profile of DC Distribution Network with DG Access

    Science.gov (United States)

    Tu, J. J.; Yin, Z. D.

    2017-07-01

    With the development of electronic, more and more distributed generations (DGs) access into grid and cause the research fever of direct current (DC) distribution network. Considering distributed generation (DG) location and capacity have great impacts on voltage profile, so use IEEE9 and IEEE33 typical circuit as examples, with DGs access in centralized and decentralized mode, to compare voltage profile in alternating and direct current (AC/DC) distribution network. Introducing the voltage change ratio as an evaluation index, so gets the general results on voltage profile of DC distributed network with DG access. Simulation shows that, in the premise of reasonable location and capacity, DC distribution network is more suitable for DG access.

  17. Directional Dependence in Developmental Research

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this article, we discuss and propose methods that may be of use to determine direction of dependence in non-normally distributed variables. First, it is shown that standard regression analysis is unable to distinguish between explanatory and response variables. Then, skewness and kurtosis are discussed as tools to assess deviation from…

  18. A Proposal for the Distribution of Federal Block Grant Funds in Illinois.

    Science.gov (United States)

    Hickrod, G. Alan; And Others

    It is proposed that federal block grants to Illinois be distributed to school districts according to four characteristics of those districts. Funds will be distributed inversely proportional to property valuation per pupil, directly proportional to percentage of minority children, directly proportional to percentage of poverty children (Title I…

  19. A Distributional Representation Model For Collaborative Filtering

    OpenAIRE

    Junlin, Zhang; Heng, Cai; Tongwen, Huang; Huiping, Xue

    2015-01-01

    In this paper, we propose a very concise deep learning approach for collaborative filtering that jointly models distributional representation for users and items. The proposed framework obtains better performance when compared against current state-of-art algorithms and that made the distributional representation model a promising direction for further research in the collaborative filtering.

  20. Distributed sensor networks

    CERN Document Server

    Rubin, Donald B; Carlin, John B; Iyengar, S Sitharama; Brooks, Richard R; University, Clemson

    2014-01-01

    An Overview, S.S. Iyengar, Ankit Tandon, and R.R. BrooksMicrosensor Applications, David ShepherdA Taxonomy of Distributed Sensor Networks, Shivakumar Sastry and S.S. IyengarContrast with Traditional Systems, R.R. BrooksDigital Signal Processing Background, Yu Hen HuImage-Processing Background Lynne Grewe and Ben ShahshahaniObject Detection and Classification, Akbar M. SayeedParameter Estimation David FriedlanderTarget Tracking with Self-Organizing Distributed Sensors R.R. Brooks, C. Griffin, D.S. Friedlander, and J.D. KochCollaborative Signal and Information Processing: AnInformation-Directed Approach Feng Zhao, Jie Liu, Juan Liu, Leonidas Guibas, and James ReichEnvironmental Effects, David C. SwansonDetecting and Counteracting Atmospheric Effects Lynne L. GreweSignal Processing and Propagation for Aeroacoustic Sensor Networks, Richard J. Kozick, Brian M. Sadler, and D. Keith WilsonDistributed Multi-Target Detection in Sensor Networks Xiaoling Wang, Hairong Qi, and Steve BeckFoundations of Data Fusion f...

  1. Paxillin localisation in osteocytes-Is it determined by the direction of loading?

    International Nuclear Information System (INIS)

    Vatsa, A.; Semeins, C.M.; Smit, T.H.; Klein-Nulend, J.

    2008-01-01

    External mechanical loading of cells aligns cytoskeletal stress fibres in the direction of principle strains and localises paxillin to the mechanosensing region. If the osteocyte cell body can indeed directly sense matrix strains, then cytoskeletal alignment and distribution of paxillin in osteocytes in situ will bear alignment to the different mechanical loading patterns in fibulae and calvariae. We used confocal microscopy to visualise the immunofluorescence-labelled actin cytoskeleton in viable osteocytes and paxillin distribution in fixated osteocytes in situ. In fibular osteocyte cell bodies, actin cytoskeleton and nuclei were elongated and aligned parallel to the principal (longitudinal) mechanical loading direction. Paxillin was localised to the 'poles' of elongated osteocyte cell bodies. In calvarial osteocyte cell bodies, actin cytoskeleton and nuclei were relatively more round. Paxillin was distributed evenly in the osteocyte cell bodies. Thus in osteocyte cell bodies in situ, the external mechanical loading pattern likely determines the orientation of the actin cytoskeleton, and focal adhesions mediate direct mechanosensation of matrix strains.

  2. Over-Distribution in Source Memory

    Science.gov (United States)

    Brainerd, C. J.; Reyna, V. F.; Holliday, R. E.; Nakamura, K.

    2012-01-01

    Semantic false memories are confounded with a second type of error, over-distribution, in which items are attributed to contradictory episodic states. Over-distribution errors have proved to be more common than false memories when the two are disentangled. We investigated whether over-distribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly over-distribution errors, but unlike semantic false memory, over-distribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of over-distribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list-order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that predicts that (a) over-distribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions. PMID:21942494

  3. Collective motions of globally coupled oscillators and some probability distributions on circle

    Energy Technology Data Exchange (ETDEWEB)

    Jaćimović, Vladimir [Faculty of Natural Sciences and Mathematics, University of Montenegro, Cetinjski put, bb., 81000 Podgorica (Montenegro); Crnkić, Aladin, E-mail: aladin.crnkic@hotmail.com [Faculty of Technical Engineering, University of Bihać, Ljubijankićeva, bb., 77000 Bihać, Bosnia and Herzegovina (Bosnia and Herzegovina)

    2017-06-28

    In 2010 Kato and Jones described a new family of probability distributions on circle, obtained as Möbius transformation of von Mises distribution. We present the model demonstrating that these distributions appear naturally in study of populations of coupled oscillators. We use this opportunity to point out certain relations between Directional Statistics and collective motion of coupled oscillators. - Highlights: • We specify probability distributions on circle that arise in Kuramoto model. • We study how the mean-field coupling affects the shape of distribution of phases. • We discuss potential applications in some experiments on cell cycle. • We apply Directional Statistics to study collective dynamics of coupled oscillators.

  4. Angular distributions of sputtered particles from lithium-implanted aluminium and copper crystals

    International Nuclear Information System (INIS)

    Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Andersen, H.H.; Buhanov, V.M.; Chernysh, V.S.; Ivanov, I.N.; Minnebaev, K.F.

    1991-01-01

    The anisotropy of angular distributions of sputtered ions from lithium implanted aluminium and copper single crystals, measured by SIMS analysis, have been used to obtain information about the microstructure of the implanted layers. Sputtered Al + distributions from the {111} surface show three-fold symmetry with maximum intensity near the and directions respectively, while Li + distributions show maximum intensity only in the directions. From {100} crystals the Al + distributions have four-fold symmetry while there are no preferential ejection directions for the Li + ions. This agrees conceptually with the fact that the implanted layer contains the ordered Al 3 Li (δ') phase, which has earlier been observed by TEM analysis on implanted samples. In contrast, a similar study of Li + implanted copper crystals shows that the implanted lithium is randomly located. (orig.)

  5. Discovery potential for directional dark matter detection with nuclear emulsions

    Science.gov (United States)

    Guler, A. M.; NEWSdm Collaboration

    2017-06-01

    Direct Dark Matter searches are nowadays one of the most exciting research topics. Several Experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs). In this field a new frontier can be opened by directional detectors able to reconstruct the direction of the WIMP-recoiled nucleus thus allowing to extend dark matter searches beyond the neutrino floor. Exploiting directionality would also give a proof of the galactic origin of dark matter making it possible to have a clear and unambiguous signal to background separation. The angular distribution of WIPM-scattered nuclei is indeed expected to be peaked in the direction of the motion of the Solar System in the Galaxy, i.e. toward the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on the use of gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we show the potentiality in terms of exclusion limit of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution.

  6. Electro-optic measurement of terahertz pulse energy distribution

    NARCIS (Netherlands)

    Sun, J.H.; Gallacher, J.G.; Brussaard, G.J.H.; Lemos, N.; Issac, R.; Huang, Z.X.; Dias, J.M.; Jaroszynski, D.A.

    2009-01-01

    An accurate and direct measurement of the energy distribution of a low repetition rate terahertz electromagnetic pulse is challenging because of the lack of sensitive detectors in this spectral range. In this paper, we show how the total energy and energy density distribution of a terahertz

  7. Kemari: A Portable High Performance Fortran System for Distributed Memory Parallel Processors

    Directory of Open Access Journals (Sweden)

    T. Kamachi

    1997-01-01

    Full Text Available We have developed a compilation system which extends High Performance Fortran (HPF in various aspects. We support the parallelization of well-structured problems with loop distribution and alignment directives similar to HPF's data distribution directives. Such directives give both additional control to the user and simplify the compilation process. For the support of unstructured problems, we provide directives for dynamic data distribution through user-defined mappings. The compiler also allows integration of message-passing interface (MPI primitives. The system is part of a complete programming environment which also comprises a parallel debugger and a performance monitor and analyzer. After an overview of the compiler, we describe the language extensions and related compilation mechanisms in detail. Performance measurements demonstrate the compiler's applicability to a variety of application classes.

  8. Seasonal distribution of Legionella spp. and L. pneumophila in a river in Taiwan evaluated with culture-confirmed and direct DNA extraction methods

    Science.gov (United States)

    Tung, Min-Che; Chang, Tien-Yu; Hsu, Bing-Mu; Shen, Shu-Min; Huang, Jen-Te; Kao, Po-Min; Chiu, Yi-Chou; Fan, Cheng-Wei; Huang, Yu-Li

    2013-07-01

    In this study, we evaluated the presence and amount of Legionella in along a river in Taiwan, and the relations between seasonal distribution of Legionella spp. and geographic characteristics in the watershed were also evaluated. Water samples were pre-treated and analyzed with culture-confirmed and direct DNA extraction methods. For culture-confirmed method, water samples were cultivated through a series of selective media, and candidate colonies were confirmed by PCR. For direct DNA extraction method, direct DNA extraction was performed from pre-treated water samples. The DNA extracts were analyzed with PCR and DNA sequence analysis for species determination, quantitative PCR (qPCR) was performed to quantify Legionella concentration in the water sample. In all, 150 water samples were included in this study, with 73 (48.6%) water samples detected with Legionella spp., and 17 with L. pneumophila. Over 80% Legionella spp. detections were through direct DNA extraction method, but more than 80% L. pneumophila detections were through culture-confirmed method. While detection of Legionella spp. was done with two methods, positive results were found through only one method. Legionella spp. was detected in all seasons with detection rate ranging between 34.3-58.8% and seasonal average concentration from 1.9 × 102 to 7.1 × 103 CFU/L. Most of the L. pneumophila detections were from samples collected in fall (38.2%) and summer (6.0%), which also coincided with increased cases of Legionellosis reported through Center of Disease Control in Taiwan. The high prevalence and concentration of Legionella spp. and L. pneumophila in the surface waters should be further evaluated for potential health risks.

  9. Gas-Fired Distributed Energy Resource Technology Characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, L.; Hedman, B.; Knowles, D.; Freedman, S. I.; Woods, R.; Schweizer, T.

    2003-11-01

    The U. S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) is directing substantial programs in the development and encouragement of new energy technologies. Among them are renewable energy and distributed energy resource technologies. As part of its ongoing effort to document the status and potential of these technologies, DOE EERE directed the National Renewable Energy Laboratory to lead an effort to develop and publish Distributed Energy Technology Characterizations (TCs) that would provide both the department and energy community with a consistent and objective set of cost and performance data in prospective electric-power generation applications in the United States. Toward that goal, DOE/EERE - joined by the Electric Power Research Institute (EPRI) - published the Renewable Energy Technology Characterizations in December 1997.As a follow-up, DOE EERE - joined by the Gas Research Institute - is now publishing this document, Gas-Fired Distributed Energy Resource Technology Characterizations.

  10. Variation of wave directional spread parameters along the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.

    through a directional wave spectrum, which represents distribution of wave energies over various wave frequencies and directions. Most widely practiced technique for directional data collection involves use of the floating buoys. The data analysis.... Estimation of directional spectra from the maximum entropy principle, Proceedings 5th International Conference on Offshore Mechanics and Arctic Engineering, Tokyo, Japan 1986; vol. I: 80-85. [6] Kuik AJ, Vledder G, Holthuijsen LH. A method for the routine...

  11. Fisher statistics for analysis of diffusion tensor directional information.

    Science.gov (United States)

    Hutchinson, Elizabeth B; Rutecki, Paul A; Alexander, Andrew L; Sutula, Thomas P

    2012-04-30

    A statistical approach is presented for the quantitative analysis of diffusion tensor imaging (DTI) directional information using Fisher statistics, which were originally developed for the analysis of vectors in the field of paleomagnetism. In this framework, descriptive and inferential statistics have been formulated based on the Fisher probability density function, a spherical analogue of the normal distribution. The Fisher approach was evaluated for investigation of rat brain DTI maps to characterize tissue orientation in the corpus callosum, fornix, and hilus of the dorsal hippocampal dentate gyrus, and to compare directional properties in these regions following status epilepticus (SE) or traumatic brain injury (TBI) with values in healthy brains. Direction vectors were determined for each region of interest (ROI) for each brain sample and Fisher statistics were applied to calculate the mean direction vector and variance parameters in the corpus callosum, fornix, and dentate gyrus of normal rats and rats that experienced TBI or SE. Hypothesis testing was performed by calculation of Watson's F-statistic and associated p-value giving the likelihood that grouped observations were from the same directional distribution. In the fornix and midline corpus callosum, no directional differences were detected between groups, however in the hilus, significant (pstatistical comparison of tissue structural orientation. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Income dynamics with a stationary double Pareto distribution.

    Science.gov (United States)

    Toda, Alexis Akira

    2011-04-01

    Once controlled for the trend, the distribution of personal income appears to be double Pareto, a distribution that obeys the power law exactly in both the upper and the lower tails. I propose a model of income dynamics with a stationary distribution that is consistent with this fact. Using US male wage data for 1970-1993, I estimate the power law exponent in two ways--(i) from each cross section, assuming that the distribution has converged to the stationary distribution, and (ii) from a panel directly estimating the parameters of the income dynamics model--and obtain the same value of 8.4.

  13. Light distribution system comprising spectral conversion means

    DEFF Research Database (Denmark)

    2012-01-01

    , longer wavelength,a spectral conversion characteristics of the spectral conversion fibre being essentially determined by the spectral absorption and emission properties of the photoluminescent agent, the amount of photo- luminescent agent,and the distribution of the photoluminescent agent in the spectral......System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side...... of providing a light distribution system and a method of correcting the spectral transmission characteristics of a light distribution system are disclosed....

  14. Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

    KAUST Repository

    Yukawa, Satoshi

    2009-02-15

    A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

  15. Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

    KAUST Repository

    Yukawa, Satoshi; Shimada, Takashi; Ogushi, Fumiko; Ito, Nobuyasu

    2009-01-01

    A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

  16. Flood impacts on a water distribution network

    Science.gov (United States)

    Arrighi, Chiara; Tarani, Fabio; Vicario, Enrico; Castelli, Fabio

    2017-12-01

    Floods cause damage to people, buildings and infrastructures. Water distribution systems are particularly exposed, since water treatment plants are often located next to the rivers. Failure of the system leads to both direct losses, for instance damage to equipment and pipework contamination, and indirect impact, since it may lead to service disruption and thus affect populations far from the event through the functional dependencies of the network. In this work, we present an analysis of direct and indirect damages on a drinking water supply system, considering the hazard of riverine flooding as well as the exposure and vulnerability of active system components. The method is based on interweaving, through a semi-automated GIS procedure, a flood model and an EPANET-based pipe network model with a pressure-driven demand approach, which is needed when modelling water distribution networks in highly off-design conditions. Impact measures are defined and estimated so as to quantify service outage and potential pipe contamination. The method is applied to the water supply system of the city of Florence, Italy, serving approximately 380 000 inhabitants. The evaluation of flood impact on the water distribution network is carried out for different events with assigned recurrence intervals. Vulnerable elements exposed to the flood are identified and analysed in order to estimate their residual functionality and to simulate failure scenarios. Results show that in the worst failure scenario (no residual functionality of the lifting station and a 500-year flood), 420 km of pipework would require disinfection with an estimated cost of EUR 21 million, which is about 0.5 % of the direct flood losses evaluated for buildings and contents. Moreover, if flood impacts on the water distribution network are considered, the population affected by the flood is up to 3 times the population directly flooded.

  17. Analysis of the theoretical bias in dark matter direct detection

    International Nuclear Information System (INIS)

    Catena, Riccardo

    2014-01-01

    Fitting the model ''A'' to dark matter direct detection data, when the model that underlies the data is ''B'', introduces a theoretical bias in the fit. We perform a quantitative study of the theoretical bias in dark matter direct detection, with a focus on assumptions regarding the dark matter interactions, and velocity distribution. We address this problem within the effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. We analyze 24 benchmark points in the parameter space of the theory, using frequentist and Bayesian statistical methods. First, we simulate the data of future direct detection experiments assuming a momentum/velocity dependent dark matter-nucleon interaction, and an anisotropic dark matter velocity distribution. Then, we fit a constant scattering cross section, and an isotropic Maxwell-Boltzmann velocity distribution to the simulated data, thereby introducing a bias in the analysis. The best fit values of the dark matter particle mass differ from their benchmark values up to 2 standard deviations. The best fit values of the dark matter-nucleon coupling constant differ from their benchmark values up to several standard deviations. We conclude that common assumptions in dark matter direct detection are a source of potentially significant bias

  18. Direct observation of two dimensional trace gas distributions with an airborne Imaging DOAS instrument

    Directory of Open Access Journals (Sweden)

    K.-P. Heue

    2008-11-01

    Full Text Available In many investigations of tropospheric chemistry information about the two dimensional distribution of trace gases on a small scale (e.g. tens to hundreds of metres is highly desirable. An airborne instrument based on imaging Differential Optical Absorption Spectroscopy has been built to map the two dimensional distribution of a series of relevant trace gases including NO2, HCHO, C2H2O2, H2O, O4, SO2, and BrO on a scale of 100 m.

    Here we report on the first tests of the novel aircraft instrument over the industrialised South African Highveld, where large variations in NO2 column densities in the immediate vicinity of several sources e.g. power plants or steel works, were measured. The observed patterns in the trace gas distribution are interpreted with respect to flux estimates, and it is seen that the fine resolution of the measurements allows separate sources in close proximity to one another to be distinguished.

  19. Distributed Cloud Storage Using Network Coding

    OpenAIRE

    Sipos, Marton A.; Fitzek, Frank; Roetter, Daniel Enrique Lucani; Pedersen, Morten Videbæk

    2014-01-01

    Distributed storage is usually considered within acloud provider to ensure availability and reliability of the data.However, the user is still directly dependent on the quality of asingle system. It is also entrusting the service provider with largeamounts of private data, which may be accessed by a successfulattack to that cloud system or even be inspected by governmentagencies in some countries. This paper advocates a generalframework for network coding enabled distributed storage overmulti...

  20. Multimedia Distribution: A View from the Supply Side.

    Science.gov (United States)

    Kesten, Myles

    1998-01-01

    Describes how multimedia products start as ideas and go through the stages of design, production, manufacturing, and marketing. Highlights include corporate consolidation, market distribution in 1997, encyclopedias and the growing Internet trend, direct marketers and sales, CD-ROM and DVD (digital video disk), costs, and future directions. (AEF)

  1. Research on intelligent power distribution system for spacecraft

    Science.gov (United States)

    Xia, Xiaodong; Wu, Jianju

    2017-10-01

    The power distribution system (PDS) mainly realizes the power distribution and management of the electrical load of the whole spacecraft, which is directly related to the success or failure of the mission, and hence is an important part of the spacecraft. In order to improve the reliability and intelligent degree of the PDS, and considering the function and composition of spacecraft power distribution system, this paper systematically expounds the design principle and method of the intelligent power distribution system based on SSPC, and provides the analysis and verification of the test data additionally.

  2. Direct observation of free-exciton thermalization in quantum-well structures

    DEFF Research Database (Denmark)

    Umlauff, M.; Hoffmann, J.; Kalt, H.

    1998-01-01

    We report on a direct observation of free-exciton thermalization in quantum-well structures. A narrow energy distribution of free 1s excitons is created in ZnSe-based quantum wells by emission of one LO phonon after optical excitation of the continuum stales with picosecond laser pulses. The subs......We report on a direct observation of free-exciton thermalization in quantum-well structures. A narrow energy distribution of free 1s excitons is created in ZnSe-based quantum wells by emission of one LO phonon after optical excitation of the continuum stales with picosecond laser pulses...

  3. Distribution management by means of cutoff order size: a case study

    NARCIS (Netherlands)

    R. Nass; R. Dekker (Rommert); W. van Sonderen-Huisman

    1997-01-01

    textabstractWe present a case study on physical distribution management for a production company in Western Europe. The company delivers finished goods both from distribution centers and directly from plants to its customers. The lead time from distribution centres is shorter, but higher costs are

  4. Smart curtailment for congestion management in LV distribution network

    NARCIS (Netherlands)

    Haque, A. N.M.M.; Rahman, M. T.; Nguyen, P. H.; Bliek, F. W.

    2016-01-01

    The rapid proliferation of distributed energy resources (DERs) leads to capacity challenges, i.e. network congestions, in the low-voltage (LV) distribution networks. A number of strategies are being widely studied to tackle the challenges with direct switching actions such as load shedding or power

  5. 21 CFR 1140.16 - Conditions of manufacture, sale, and distribution.

    Science.gov (United States)

    2010-04-01

    ... smokeless tobacco only in a direct, face-to-face exchange between the retailer and the consumer. Examples of... retailer may distribute or cause to be distributed any free samples of smokeless tobacco: (i) To a sports...

  6. Inverse identification of intensity distributions from multiple flux maps in concentrating solar applications

    International Nuclear Information System (INIS)

    Erickson, Ben; Petrasch, Jörg

    2012-01-01

    Radiative flux measurements at the focal plane of solar concentrators are typically performed using digital cameras in conjunction with Lambertian targets. To accurately predict flux distributions on arbitrary receiver geometries directional information about the radiation is required. Currently, the directional characteristics of solar concentrating systems are predicted via ray tracing simulations. No direct experimental technique to determine intensities of concentrating solar systems is available. In the current paper, multiple parallel flux measurements at varying distances from the focal plane together with a linear inverse method and Tikhonov regularization are used to identify the directional and spatial intensity distribution at the solution plane. The directional binning feature of an in-house Monte Carlo ray tracing program is used to provide a reference solution. The method has been successfully applied to two-dimensional concentrators, namely parabolic troughs and elliptical troughs using forward Monte Carlo ray tracing simulations that provide the flux maps as well as consistent, associated intensity distribution for validation. In the two-dimensional case, intensity distributions obtained from the inverse method approach the Monte Carlo forward solution. In contrast, the method has not been successful for three dimensional and circular symmetric concentrator geometries.

  7. Tsallis distribution as a standard maximum entropy solution with 'tail' constraint

    International Nuclear Information System (INIS)

    Bercher, J.-F.

    2008-01-01

    We show that Tsallis' distributions can be derived from the standard (Shannon) maximum entropy setting, by incorporating a constraint on the divergence between the distribution and another distribution imagined as its tail. In this setting, we find an underlying entropy which is the Renyi entropy. Furthermore, escort distributions and generalized means appear as a direct consequence of the construction. Finally, the 'maximum entropy tail distribution' is identified as a Generalized Pareto Distribution

  8. Experiments to measure the gluon helicity distribution in protons

    International Nuclear Information System (INIS)

    Spinka, H.; Beddo, M.E.; Underwood, D.G.

    1993-01-01

    Several experiments are described that could obtain information about the gluon helicity distribution in protons. These experiments include inclusive direct-γ, direct-γ + jet, jet, and jet + jet production with colliding beams of longitudinally-polarized protons. Some rates and kinematics are also discussed

  9. 2015 Plan. Project 6: urban and rural distribution systems

    International Nuclear Information System (INIS)

    1993-06-01

    The main development trends of distribution systems in 2015 Plan is studied, with the data of market continuity, costs and evolution of the physique system. Some factors that will influence the evolution of the distribution systems are presented and the impacts of economic view are discussed. The strategic lines that will give direction for the distribution expansion, including the energy conservation are also shown. (C.G.C.)

  10. Comparison of NGA-West2 directivity models

    Science.gov (United States)

    Spudich, Paul A.; Rowshandel, Badie; Shahi, Shrey; Baker, Jack W.; Chiou, Brian S-J

    2014-01-01

    Five directivity models have been developed based on data from the NGA-West2 database and based on numerical simulations of large strike-slip and reverse-slip earthquakes. All models avoid the use of normalized rupture dimension, enabling them to scale up to the largest earthquakes in a physically reasonable way. Four of the five models are explicitly “narrow-band” (in which the effect of directivity is maximum at a specific period that is a function of earthquake magnitude). Several strategies for determining the zero-level for directivity have been developed. We show comparisons of maps of the directivity amplification. This comparison suggests that the predicted geographic distributions of directivity amplification are dominated by effects of the models' assumptions, and more than one model should be used for ruptures dipping less than about 65 degrees.

  11. Cloud Computing as Evolution of Distributed Computing – A Case Study for SlapOS Distributed Cloud Computing Platform

    Directory of Open Access Journals (Sweden)

    George SUCIU

    2013-01-01

    Full Text Available The cloud computing paradigm has been defined from several points of view, the main two directions being either as an evolution of the grid and distributed computing paradigm, or, on the contrary, as a disruptive revolution in the classical paradigms of operating systems, network layers and web applications. This paper presents a distributed cloud computing platform called SlapOS, which unifies technologies and communication protocols into a new technology model for offering any application as a service. Both cloud and distributed computing can be efficient methods for optimizing resources that are aggregated from a grid of standard PCs hosted in homes, offices and small data centers. The paper fills a gap in the existing distributed computing literature by providing a distributed cloud computing model which can be applied for deploying various applications.

  12. Significance tests to determine the direction of effects in linear regression models.

    Science.gov (United States)

    Wiedermann, Wolfgang; Hagmann, Michael; von Eye, Alexander

    2015-02-01

    Previous studies have discussed asymmetric interpretations of the Pearson correlation coefficient and have shown that higher moments can be used to decide on the direction of dependence in the bivariate linear regression setting. The current study extends this approach by illustrating that the third moment of regression residuals may also be used to derive conclusions concerning the direction of effects. Assuming non-normally distributed variables, it is shown that the distribution of residuals of the correctly specified regression model (e.g., Y is regressed on X) is more symmetric than the distribution of residuals of the competing model (i.e., X is regressed on Y). Based on this result, 4 one-sample tests are discussed which can be used to decide which variable is more likely to be the response and which one is more likely to be the explanatory variable. A fifth significance test is proposed based on the differences of skewness estimates, which leads to a more direct test of a hypothesis that is compatible with direction of dependence. A Monte Carlo simulation study was performed to examine the behaviour of the procedures under various degrees of associations, sample sizes, and distributional properties of the underlying population. An empirical example is given which illustrates the application of the tests in practice. © 2014 The British Psychological Society.

  13. A Linear Algebra Framework for Static High Performance Fortran Code Distribution

    Directory of Open Access Journals (Sweden)

    Corinne Ancourt

    1997-01-01

    Full Text Available High Performance Fortran (HPF was developed to support data parallel programming for single-instruction multiple-data (SIMD and multiple-instruction multiple-data (MIMD machines with distributed memory. The programmer is provided a familiar uniform logical address space and specifies the data distribution by directives. The compiler then exploits these directives to allocate arrays in the local memories, to assign computations to elementary processors, and to migrate data between processors when required. We show here that linear algebra is a powerful framework to encode HPF directives and to synthesize distributed code with space-efficient array allocation, tight loop bounds, and vectorized communications for INDEPENDENT loops. The generated code includes traditional optimizations such as guard elimination, message vectorization and aggregation, and overlap analysis. The systematic use of an affine framework makes it possible to prove the compilation scheme correct.

  14. Research on the optimization of vehicle distribution routes in logistics enterprises

    Science.gov (United States)

    Fan, Zhigou; Ma, Mengkun

    2018-01-01

    With the rapid development of modern logistics, the vehicle routing problem has become one of the urgent problems in the logistics industry. The rationality of distribution route planning directly affects the efficiency and quality of logistics distribution. This paper first introduces the definition of logistics distribution and the three methods of optimizing the distribution routes, and then analyzes the current vehicle distribution route by using a representative example, finally puts forward the optimization schemes of logistics distribution route.

  15. Halo-Independent Direct Detection Analyses Without Mass Assumptions

    CERN Document Server

    Anderson, Adam J.; Kahn, Yonatan; McCullough, Matthew

    2015-10-06

    Results from direct detection experiments are typically interpreted by employing an assumption about the dark matter velocity distribution, with results presented in the $m_\\chi-\\sigma_n$ plane. Recently methods which are independent of the DM halo velocity distribution have been developed which present results in the $v_{min}-\\tilde{g}$ plane, but these in turn require an assumption on the dark matter mass. Here we present an extension of these halo-independent methods for dark matter direct detection which does not require a fiducial choice of the dark matter mass. With a change of variables from $v_{min}$ to nuclear recoil momentum ($p_R$), the full halo-independent content of an experimental result for any dark matter mass can be condensed into a single plot as a function of a new halo integral variable, which we call $\\tilde{h}(p_R)$. The entire family of conventional halo-independent $\\tilde{g}(v_{min})$ plots for all DM masses are directly found from the single $\\tilde{h}(p_R)$ plot through a simple re...

  16. Asymmetric active nano-particles for directive near-field radiation

    DEFF Research Database (Denmark)

    Arslanagic, Samel; Thorsen, Rasmus O.

    2016-01-01

    In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

  17. Direct Thermodynamic Measurements of the Energetics of Information Processing

    Science.gov (United States)

    2017-08-08

    Title: Direct thermodynamic measurements of the energetics of information processing Report Term: 0-Other Email : roukes@caltech.edu Distribution...INVESTIGATOR(S): Phone Number: 6263952916 Principal: Y Name: PhD Michael L. Roukes Email : roukes@caltech.edu PARTICIPANTS: Person Months Worked: 1.00... writing of this final DURIP report. These initial data directly demonstrate our ability to drive and detect nanomechanical motion at ultralow

  18. CUMULVS: Collaborative infrastructure for developing distributed simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kohl, J.A.; Papadopoulos, P.M.; Geist, G.A. II

    1997-03-01

    The CUMULVS software environment provides remote collaboration among scientists by allowing them to dynamically attach to, view, and steer a running simulation. Users can interactively examine intermediate results on demand, saving effort for long-running applications gone awry. In addition, it provides fault tolerance to distributed applications via user-directed checkpointing, heterogeneous task migration and automatic restart. This talk describes CUMULVS and how this tool benefits scientists developing large distributed applications.

  19. Institutional distributed energy interconnection barriers

    International Nuclear Information System (INIS)

    Castelaz, S.A.

    2002-01-01

    This PowerPoint presentation provided an introduction to Encorp Inc., a leading provider of network technology and infrastructure management solutions for the distributed energy market. Encorp develops and markets software and hardware technology solutions for communications, control and networking of distributed energy. It is developing and implementing real-time, distributed energy-focused solutions for a wide variety of applications through new products and services which are technology neutral, and easily networked. Encorp controls more than 500 MW of distributed power with a total of 127 customers. This paper reviewed 3 barriers (regulatory, contractual/tariffs, and business practices) based on US experience. The challenge remaining is to determine if microgrids can be used effectively, and to determine the limitations of bi-directional power flows. The key issues regarding how end-users can share the costs and maximize on the benefits of distributed energy resources include: standby service charges, departing load charges, regulatory uncertainty, rate class degradation, lack of incentives for utility cost reduction, and lack of ability to create experimental tariffs. tabs., figs

  20. Cometary dust size distributions from flyby spacecraft

    International Nuclear Information System (INIS)

    Divine, N.

    1988-01-01

    Pior to the Halley flybys in 1986, the distribution of cometary dust grains with particle size were approximated using models which provided reasonable fits to the dynamics of dust tails, anti-tails, and infrared spectra. These distributions have since been improved using fluence data (i.e., particle fluxes integrated over time along the flyby trajectory) from three spacecraft. The fluence derived distributions are appropriate for comparison with simultaneous infrared photometry (from Earth) because they sample the particles in the same way as the IR data do (along the line of sight) and because they are directly proportional to the concentration distribution in that region of the coma which dominates the IR emission

  1. Critical review of directional neutron survey meters

    Science.gov (United States)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2014-01-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument.

  2. Critical Review of Directional Neutron Survey Meters

    International Nuclear Information System (INIS)

    Balmer, M.J.I.; Gamage, K.A.A.; Taylor, G.C.

    2013-06-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument. (authors)

  3. Assessing Tax Form Distribution Costs: A Proposed Method for Computing the Dollar Value of Tax Form Distribution in a Public Library.

    Science.gov (United States)

    Casey, James B.

    1998-01-01

    Explains how a public library can compute the actual cost of distributing tax forms to the public by listing all direct and indirect costs and demonstrating the formulae and necessary computations. Supplies directions for calculating costs involved for all levels of staff as well as associated public relations efforts, space, and utility costs.…

  4. Identification of Requirements for Distribution Management Systems in the Smart Grid Context

    DEFF Research Database (Denmark)

    Rezkalla, Michel M.N.; Heussen, Kai; Marinelli, Mattia

    2015-01-01

    The integration of significant volumes of distributed and renewable energy resources directly connected to the distribution network raises new requirement to maintain and operate the power system in secure state. Thus the Distribution Management System (DMS) needs to be updated and integrated...

  5. Generalised extreme value distributions provide a natural hypothesis for the shape of seed mass distributions.

    Directory of Open Access Journals (Sweden)

    Will Edwards

    Full Text Available Among co-occurring species, values for functionally important plant traits span orders of magnitude, are uni-modal, and generally positively skewed. Such data are usually log-transformed "for normality" but no convincing mechanistic explanation for a log-normal expectation exists. Here we propose a hypothesis for the distribution of seed masses based on generalised extreme value distributions (GEVs, a class of probability distributions used in climatology to characterise the impact of event magnitudes and frequencies; events that impose strong directional selection on biological traits. In tests involving datasets from 34 locations across the globe, GEVs described log10 seed mass distributions as well or better than conventional normalising statistics in 79% of cases, and revealed a systematic tendency for an overabundance of small seed sizes associated with low latitudes. GEVs characterise disturbance events experienced in a location to which individual species' life histories could respond, providing a natural, biological explanation for trait expression that is lacking from all previous hypotheses attempting to describe trait distributions in multispecies assemblages. We suggest that GEVs could provide a mechanistic explanation for plant trait distributions and potentially link biology and climatology under a single paradigm.

  6. Multi-directional random wave interaction with an array of cylinders

    DEFF Research Database (Denmark)

    Ji, Xinran; Liu, Shuxue; Bingham, Harry B.

    2015-01-01

    Based on the linear theory of wave interaction with an array of circular bottom-mounted vertical cylinders, systematic calculations are made to investigate the effects of the wave directionality on wave loads in short-crested seas. The multi-directional waves are specified using a discrete form...... of the Mitsuyasu-type spreading function. The time series of multi-directional wave loads, including both the wave run-up and wave force, can be simulated. The effect of wave directionality on the wave run-up and wave loading on the cylinders is investigated. For multi-directional waves, as the distribution...

  7. Directional spread parameter at intermediate water depth

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Deo, M.C.; Anand, N.M.; AshokKumar, K.

    ’ involves only the significant wave height, zero crossing wave period and water depth, the spreading function based on ‘s 3 ’ can be used for practical appli- cation. In the model based on ‘s 3 ’ the mean wave direction is an input and this has...-linearity parameter can be recommended for practical use as it provides an averaged distribution. Acknowledgements The authors would like to thank the Department of Science and Technology, New Delhi, for funding the project titled “Directional wave modelling...

  8. Relaxation of Distributed Data Aggregation for Underwater Acoustic Sensor Networks

    Science.gov (United States)

    2014-03-31

    2 3.1 Gossip algorithms for distributed averaging . . . . . . . . . . . . . . . . . 3 3.2 Distributed particle filtering...algorithm that had direct access to all of the measurements. We use gossip algorithms (discussed in Section 3.1) to diffuse information across the...2 3.1 Gossip algorithms for distributed averaging We begin by discussing gossip algorithms, which we use to synchronize and spread infor- mation

  9. Distributed Generation to Support Development-Focused Climate Action

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sadie; Gagnon, Pieter; Stout, Sherry; Zinaman, Owen; Watson, Andrea; Hotchkiss, Eliza

    2016-09-01

    This paper explores the role of distributed generation, with a high renewable energy contribution, in supporting low emission climate-resilient development. The paper presents potential impacts on development (via energy access), greenhouse gas emission mitigation, and climate resilience directly associated with distributed generation, as well as specific actions that may enhance or increase the likelihood of climate and development benefits. This paper also seeks to provide practical and timely insights to support distributed generation policymaking and planning within the context of common climate and development goals as the distributed generation landscape rapidly evolves globally. Country-specific distributed generation policy and program examples, as well as analytical tools that can inform efforts internationally, are also highlighted throughout the paper.

  10. Proceedings of the 1992 DOE-industry thermal distribution conference

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W. (ed.)

    1992-06-01

    The subject of the conference was thermal distribution in small buildings. Thermal distribution systems are the ductwork, piping, or other means used to transport heat or cooling effect from the equipment in which the heat or cooling is produced to the building spaces in which it is used. The small buildings category is defined to include single-family residential and multifamily and commercial buildings with less than 10,000 ft{sup 2} floor area. The 1992 DOE-Industry Thermal Distribution Conference was conceived as the beginning of a process of information transfer between the DOE and the industries having a stake in thermal distribution systems, whereby the DOE can make the industry aware of its thinking and planned directions early enough for changes to be made, and whereby the industries represented can provide this input to the DOE on a timely and informed basis. In accordance with this, the objectives of the Conference were: To present--to a representative group of researchers and industry representative--the current industry thinking and DOE's current directions for research in small-building thermal distribution. To obtain from industry and the research community a critique of the DOE priorities and additional ideas concerning how DOE can best assist the industry in promoting energy conservation in thermal distribution systems.

  11. Proceedings of the 1992 DOE-industry thermal distribution conference

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W. [ed.

    1992-06-01

    The subject of the conference was thermal distribution in small buildings. Thermal distribution systems are the ductwork, piping, or other means used to transport heat or cooling effect from the equipment in which the heat or cooling is produced to the building spaces in which it is used. The small buildings category is defined to include single-family residential and multifamily and commercial buildings with less than 10,000 ft{sup 2} floor area. The 1992 DOE-Industry Thermal Distribution Conference was conceived as the beginning of a process of information transfer between the DOE and the industries having a stake in thermal distribution systems, whereby the DOE can make the industry aware of its thinking and planned directions early enough for changes to be made, and whereby the industries represented can provide this input to the DOE on a timely and informed basis. In accordance with this, the objectives of the Conference were: To present--to a representative group of researchers and industry representative--the current industry thinking and DOE`s current directions for research in small-building thermal distribution. To obtain from industry and the research community a critique of the DOE priorities and additional ideas concerning how DOE can best assist the industry in promoting energy conservation in thermal distribution systems.

  12. Island Partition of Distribution System with Distributed Generators Considering Protection of Vulnerable Nodes

    Directory of Open Access Journals (Sweden)

    Gang Xu

    2017-10-01

    Full Text Available To improve the reliability of power supply in the case of the fault of distribution system with multiple distributed generators (DGs and reduce the influence of node voltage fluctuation on the stability of distribution system operation in power restoration, this paper proposes an island partition strategy of the distribution system considering the protection of vulnerable nodes. First of all, the electrical coupling coefficient of neighboring nodes is put forward according to distribution system topology and equivalent electrical impedance, and the power-dependence relationship between neighboring nodes is calculated based on the direction and level of the power flow between nodes. Then, the bidirectional transmission of the coupling features of neighboring nodes is realized through the modified PageRank algorithm, thus identifying the vulnerable nodes that have a large influence on the stability of distribution system operation. Next, combining the index of node vulnerability, an island partition model is constructed with the restoration of important loads as the primary goal. In addition, the mutually exclusive firefly algorithm (MEFA is also proposed to realize the interaction of learning and competition among fireflies, thus enhancing the globally optimal solution search ability of the algorithm proposed. The proposed island partition method is verified with a Pacific Gas and Electric Company (PG and E 60-node test system. Comparison with other methods demonstrates that the new method is feasible for the distribution system with multiple types of distributed generations and valid to enhance the stability and safety of the grid with a relatively power restoration ratio.

  13. Simultaneous distribution of AC and DC power

    Science.gov (United States)

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  14. Language Constructs for Data Partitioning and Distribution

    Directory of Open Access Journals (Sweden)

    P. Crooks

    1995-01-01

    Full Text Available This article presents a survey of language features for distributed memory multiprocessor systems (DMMs, in particular, systems that provide features for data partitioning and distribution. In these systems the programmer is freed from consideration of the low-level details of the target architecture in that there is no need to program explicit processes or specify interprocess communication. Programs are written according to the shared memory programming paradigm but the programmer is required to specify, by means of directives, additional syntax or interactive methods, how the data of the program are decomposed and distributed.

  15. Ten years statistics of wind direction and wind velocity measurements performed at the Karlsruhe Nuclear Research Center

    International Nuclear Information System (INIS)

    Becker, M.; Dilger, H.

    1979-06-01

    The measurements of wind direction and wind velocity performed at 60 m and 200 m height were evaluated for one year each and frequency distributions of the measured values were established. The velocity was divided into 1 m/s steps and the direction into 10 0 sectors. The frequency distribution of the wind direction reveals three maxima located in the southwest, northeast and north, respectively. The maximum of the frequency distribution of the wind velocity occurs between 4 and 5 m/s at 200 m height and between 3 and 4 m/s at 60 m height. (orig.) [de

  16. Robust Cyclic MUSIC Algorithm for Finding Directions in Impulsive Noise Environment

    Directory of Open Access Journals (Sweden)

    Sen Li

    2017-01-01

    Full Text Available This paper addresses the issue of direction finding of a cyclostationary signal under impulsive noise environments modeled by α-stable distribution. Since α-stable distribution does not have finite second-order statistics, the conventional cyclic correlation-based signal-selective direction finding algorithms do not work effectively. To resolve this problem, we define two robust cyclic correlation functions which are derived from robust statistics property of the correntropy and the nonlinear transformation, respectively. The MUSIC algorithm with the robust cyclic correlation matrix of the received signals of arrays is then used to estimate the direction of cyclostationary signal in the presence of impulsive noise. The computer simulation results demonstrate that the two proposed robust cyclic correlation-based algorithms outperform the conventional cyclic correlation and the fractional lower order cyclic correlation based methods.

  17. Personalized direct marketing using digital publishing

    Science.gov (United States)

    Kutty, Cheeniyil L.; Prabhakaran, Jayasree K.

    2006-02-01

    In today's cost-conscious business climate, marketing and customer service decision makers are increasingly concerned with how to increase customer response and retention rates. Companies spend large amounts of money on Customer Relationship Management (CRM) solutions and data acquisition but they don't know how to use the information stored in these systems to improve the effectiveness of their direct marketing campaigns. By leveraging the customer information they already have, companies can create personalized, printed direct mail programs that generate high response rates, greater returns, and stronger customer loyalty, while gaining a significant edge over their competitors. To reach the promised land of one-to-one direct marketing (personalized direct marketing - PDM), companies need an end-to-end solution for creating, managing, printing, and distributing personalized direct mail "on demand." Having access to digital printing is just one piece of the solution. A more complete approach includes leveraging personalization technology into a useful direct marketing tool that provides true one-to-one marketing, allowing variable images and text in a personalized direct mail. This paper discusses integration of CRM with a Print-on-Demand solution so as to create truly personalized printed marketing campaigns for one or many individuals based on the profile information, preferences and purchase history stored in the CRM.

  18. Theoretical method for determining particle distribution functions of classical systems

    International Nuclear Information System (INIS)

    Johnson, E.

    1980-01-01

    An equation which involves the triplet distribution function and the three-particle direct correlation function is obtained. This equation was derived using an analogue of the Ornstein--Zernike equation. The new equation is used to develop a variational method for obtaining the triplet distribution function of uniform one-component atomic fluids from the pair distribution function. The variational method may be used with the first and second equations in the YBG hierarchy to obtain pair and triplet distribution functions. It should be easy to generalize the results to the n-particle distribution function

  19. Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g(-1) level using LA-ICP-IDMS.

    Science.gov (United States)

    Boulyga, Sergei F; Heumann, Klaus G

    2005-10-01

    Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g(-1), 0.14 ng g(-1), 0.08 ng g(-1), 0.01 ng g(-1) and 0.06 ng g(-1) for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples.

  20. Rapid screening and distribution of bioactive compounds in different parts of Berberis petiolaris using direct analysis in real time mass spectrometry

    Directory of Open Access Journals (Sweden)

    Awantika Singh

    2015-10-01

    Full Text Available Berberis petiolaris Wall. ex G. Don, an unexplored medicinal plant belonging to the family Berberidaceae, is a large deciduous shrub found in Western Himalaya between 1800–3000 m. Chemical profiling of fruit, leaf, root and stem was done by direct analysis in real time mass spectrometry followed by multivariate analysis for discrimination among the plant parts. The bioactive compounds, including magnoflorine, berberine, jatrorrhizine, thalifendine/berberrubine, demethyleneberberine, reticuline, 8-oxoberberine, N-methyltetrahydroberberine, tetrahydropalmatine, tetrahydroberberine and palmatine, were identified by their exact mass measurement and the corresponding molecular formula of each compound. A comparative study of distribution pattern for all these bioactive alkaloids showed qualitative and quantitative variations in different parts of B. petiolaris. Principal component analysis clearly discriminated each part of B. petiolaris plant. Keywords: Berberis petiolaris, Alkaloids, Profiling, DART–TOF–MS, Statistical analysis

  1. Multi-Type Directed Scale-Free Percolation

    International Nuclear Information System (INIS)

    Shang Yilun

    2012-01-01

    In this paper, we study a long-range percolation model on the lattice ℤ d with multi-type vertices and directed edges. Each vertex x in ℤ d is independently assigned a non-negative weight W x and a type ψ x , where (W x ) xinℤ d are i.i.d. random variables, and (ψ x ) xinℤ d are also i.i.d. Conditionally on weights and types, and given λ, α > 0, the edges are independent and the probability that there is a directed edge from x to y is given by p xy = 1 - exp(-λφ ψ x ψ y W x W y /|x-y| α ), where φ ij 's are entries from a type matrix Φ. We show that, when the tail of the distribution of W x is regularly varying with exponent τ - 1, the tails of the out/in-degree distributions are both regularly varying with exponent γ = α(τ - 1)/d. We formulate conditions under which there exist critical values λ c WCC in (0, ∞) and λ c SCC in (0, ∞) such that an infinite weak component and an infinite strong component emerge, respectively, when λ exceeds them. A phase transition is established for the shortest path lengths of directed and undirected edges in the infinite component at the point γ = 2, where the out/in-degrees switch from having finite to infinite variances. The random graph model studied here features some structures of multi-type vertices and directed edges which appear naturally in many real-world networks, such as the SNS networks and computer communication networks. (condensed matter: structural, mechanical, and thermal properties)

  2. Inference of directional selection and mutation parameters assuming equilibrium.

    Science.gov (United States)

    Vogl, Claus; Bergman, Juraj

    2015-12-01

    In a classical study, Wright (1931) proposed a model for the evolution of a biallelic locus under the influence of mutation, directional selection and drift. He derived the equilibrium distribution of the allelic proportion conditional on the scaled mutation rate, the mutation bias and the scaled strength of directional selection. The equilibrium distribution can be used for inference of these parameters with genome-wide datasets of "site frequency spectra" (SFS). Assuming that the scaled mutation rate is low, Wright's model can be approximated by a boundary-mutation model, where mutations are introduced into the population exclusively from sites fixed for the preferred or unpreferred allelic states. With the boundary-mutation model, inference can be partitioned: (i) the shape of the SFS distribution within the polymorphic region is determined by random drift and directional selection, but not by the mutation parameters, such that inference of the selection parameter relies exclusively on the polymorphic sites in the SFS; (ii) the mutation parameters can be inferred from the amount of polymorphic and monomorphic preferred and unpreferred alleles, conditional on the selection parameter. Herein, we derive maximum likelihood estimators for the mutation and selection parameters in equilibrium and apply the method to simulated SFS data as well as empirical data from a Madagascar population of Drosophila simulans. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Direct reconstruction of the source intensity distribution of a clinical linear accelerator using a maximum likelihood expectation maximization algorithm.

    Science.gov (United States)

    Papaconstadopoulos, P; Levesque, I R; Maglieri, R; Seuntjens, J

    2016-02-07

    Direct determination of the source intensity distribution of clinical linear accelerators is still a challenging problem for small field beam modeling. Current techniques most often involve special equipment and are difficult to implement in the clinic. In this work we present a maximum-likelihood expectation-maximization (MLEM) approach to the source reconstruction problem utilizing small fields and a simple experimental set-up. The MLEM algorithm iteratively ray-traces photons from the source plane to the exit plane and extracts corrections based on photon fluence profile measurements. The photon fluence profiles were determined by dose profile film measurements in air using a high density thin foil as build-up material and an appropriate point spread function (PSF). The effect of other beam parameters and scatter sources was minimized by using the smallest field size ([Formula: see text] cm(2)). The source occlusion effect was reproduced by estimating the position of the collimating jaws during this process. The method was first benchmarked against simulations for a range of typical accelerator source sizes. The sources were reconstructed with an accuracy better than 0.12 mm in the full width at half maximum (FWHM) to the respective electron sources incident on the target. The estimated jaw positions agreed within 0.2 mm with the expected values. The reconstruction technique was also tested against measurements on a Varian Novalis Tx linear accelerator and compared to a previously commissioned Monte Carlo model. The reconstructed FWHM of the source agreed within 0.03 mm and 0.11 mm to the commissioned electron source in the crossplane and inplane orientations respectively. The impact of the jaw positioning, experimental and PSF uncertainties on the reconstructed source distribution was evaluated with the former presenting the dominant effect.

  4. Measurement of agglomerate strength distributions in agglomerated powders

    International Nuclear Information System (INIS)

    Ciftcioglu, M.; Aking, M.; Burkhart, L.

    1986-01-01

    Strength distributions of particle agglomerates in six different yttria powders were measured using a calibrated ultrasonic sound field. The density of sintered pellets was directly related to the agglomerate strength of each powder. No systematic relation to the sintered density was observed for bulk densities or pressure-density compaction data for the loose powders, or for pore size distributions or green densities for the pressed compacts

  5. Assessment of fragment projection hazard: probability distributions for the initial direction of fragments.

    Science.gov (United States)

    Tugnoli, Alessandro; Gubinelli, Gianfilippo; Landucci, Gabriele; Cozzani, Valerio

    2014-08-30

    The evaluation of the initial direction and velocity of the fragments generated in the fragmentation of a vessel due to internal pressure is an important information in the assessment of damage caused by fragments, in particular within the quantitative risk assessment (QRA) of chemical and process plants. In the present study an approach is proposed to the identification and validation of probability density functions (pdfs) for the initial direction of the fragments. A detailed review of a large number of past accidents provided the background information for the validation procedure. A specific method was developed for the validation of the proposed pdfs. Validated pdfs were obtained for both the vertical and horizontal angles of projection and for the initial velocity of the fragments. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Increased Observability in Electric Distribution Grids

    DEFF Research Database (Denmark)

    Prostejovsky, Alexander Maria

    infrastructure in distribution grids. Strong emphasis is placed on experimental verifications of the investigated concepts wherever applicable. Electric grids are changing, and so are the roles of system operators. The interest in sustainable energy and the rapidly increasing number of Distributed Energy...... that DSO areas are not necessarily self-sufficient. Missing power is covered by neighbouring areas to confine problems in a small region, which is demonstrated in SYSLAB on a two-area, grid-connected setup. The results highlight the advantages of harnessing the information obtained directly from...

  7. Observation of the inhomogeneous spatial distribution of MeV ions accelerated by the hydrodynamic ambipolar expansion of clusters

    International Nuclear Information System (INIS)

    Kanasaki, Masato; Jinno, Satoshi; Sakaki, Hironao; Faenov, Anatoly Ya.; Pikuz, Tatiana A.; Nishiuchi, Mamiko; Kiriyama, Hiromitsu; Kando, Masaki; Sugiyama, Akira; Kondo, Kiminori; Matsui, Ryutaro; Kishimoto, Yasuaki; Morishima, Kunihiro; Watanabe, Yukinobu; Scullion, Clare; Smyth, Ashley G.; Alejo, Aaron; Doria, Domenico; Kar, Satyabrata; Borghesi, Marco

    2015-01-01

    An inhomogeneous spatial distribution of laser accelerated carbon/oxygen ions produced via the hydrodynamic ambipolar expansion of CO_2 clusters has been measured by using CR-39 detectors. An inhomogeneous etch pits spatial distribution has appeared on the etched CR-39 detector installed on the laser propagation direction, while homogeneous ones are appeared on those installed at 45° and 90° from the laser propagation direction. From the range of ions in CR-39 obtained by using the multi-step etching technique, the averaged energies of carbon/oxygen ions for all directions are determined as 0.78 ± 0.09 MeV/n. The number of ions in the laser propagation direction is about 1.5 times larger than those in other directions. The inhomogeneous etch pits spatial distribution in the laser propagation direction could originate from an ion beam collimation and modulation by the effect of electromagnetic structures created in the laser plasma. - Highlights: • A spatial distribution of ions due to hydrodynamic ambipolar expansion is measured. • The homogeneous ion energy distribution of 0.78 ± 0.09 MeV/n is measured by CR-39. • The number of ions in the laser axis is about 1.5 times larger than other directions.

  8. Strength and tempo of directional selection in the wild

    OpenAIRE

    Hoekstra, H. E.; Hoekstra, J. M.; Berrigan, D.; Vignieri, S. N.; Hoang, A.; Hill, C. E.; Beerli, P.; Kingsolver, J. G.

    2001-01-01

    Directional selection is a major force driving adaptation and evolutionary change. However, the distribution, strength, and tempo of phenotypic selection acting on quantitative traits in natural populations remain unclear across different study systems. We reviewed the literature (1984–1997) that reported the strength of directional selection as indexed by standardized linear selection gradients (β). We asked how strong are viability and sexual selection, and whether strength of selection is ...

  9. Passive Optical Networks for the Distribution of Timed Signals in Particle Physics Experiments

    CERN Document Server

    Papakonstantinou, I; Papadopoulos,S; Troska, J; Vasey, F; Baron, S; Santos, L; Silva, S; Stejskal, P; Sigaud, C; Detraz, S; Moreira, P; Darwazeh, I

    2009-01-01

    A passive optical network for timing distribution applications based on FPGAs has been successfully demonstrated. Deterministic latency was achieved in the critical downstream direction where triggers are distributed while a burst mode receiver was successfully implemented in the upstream direction. Finally, a simple and efficient protocol was introduced for the communication between the OLT and the ONUs in the network that maximizes bandwidth utilization.

  10. Improved quasi parton distribution through Wilson line renormalization

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiunn-Wei [Department of Physics, Center for Theoretical Sciences, and Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei, 106, Taiwan (China); Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ji, Xiangdong [INPAC, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240 (China); Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, MD 20742 (United States); Zhang, Jian-Hui, E-mail: jianhui.zhang@physik.uni-regensburg.de [Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg (Germany)

    2017-02-15

    Recent developments showed that hadron light-cone parton distributions could be directly extracted from spacelike correlators, known as quasi parton distributions, in the large hadron momentum limit. Unlike the normal light-cone parton distribution, a quasi parton distribution contains ultraviolet (UV) power divergence associated with the Wilson line self energy. We show that to all orders in the coupling expansion, the power divergence can be removed by a “mass” counterterm in the auxiliary z-field formalism, in the same way as the renormalization of power divergence for an open Wilson line. After adding this counterterm, the quasi quark distribution is improved such that it contains at most logarithmic divergences. Based on a simple version of discretized gauge action, we present the one-loop matching kernel between the improved non-singlet quasi quark distribution with a lattice regulator and the corresponding quark distribution in dimensional regularization.

  11. Improved quasi parton distribution through Wilson line renormalization

    Directory of Open Access Journals (Sweden)

    Jiunn-Wei Chen

    2017-02-01

    Full Text Available Recent developments showed that hadron light-cone parton distributions could be directly extracted from spacelike correlators, known as quasi parton distributions, in the large hadron momentum limit. Unlike the normal light-cone parton distribution, a quasi parton distribution contains ultraviolet (UV power divergence associated with the Wilson line self energy. We show that to all orders in the coupling expansion, the power divergence can be removed by a “mass” counterterm in the auxiliary z-field formalism, in the same way as the renormalization of power divergence for an open Wilson line. After adding this counterterm, the quasi quark distribution is improved such that it contains at most logarithmic divergences. Based on a simple version of discretized gauge action, we present the one-loop matching kernel between the improved non-singlet quasi quark distribution with a lattice regulator and the corresponding quark distribution in dimensional regularization.

  12. Ergonomic investigation of weight distribution of laparoscopic instruments.

    Science.gov (United States)

    Lin, Chiuhsiang Joe; Chen, Hung-Jen; Lo, Ying-Chu

    2011-06-01

    Laparoscopic surgery procedures require highly specialized visually controlled movements. Investigations of industrial applications indicate that the length as well as the weight of hand-held tools substantially affects movement time (MT). Different weight distributions may have similar effects on long-shafted laparoscopic instruments when performing surgical procedures. For this reason, the current experiment aimed at finding direct evidence of the weight distribution effect in an accurate task. Ten right-handed subjects made continuous Fitts' pointing tasks using a long laparoscopic instrument. The factors and levels were target width: (2.5, 3, 3.5, and 4 cm), target distance (14, 23, and 37 cm), and weight distribution (uniform, front, middle, and rear). Weight distribution was made by chips of lead attached to the laparoscopic instrument. MT, error rate, and throughput (TP) were recorded as dependent variables. There were significant differences between the weight distribution in MT and in TP. The middle position was found to require the least time to manipulate the laparoscopic instrument in pointing tasks and also obtained the highest TP. These analyses and findings pointed to a design direction for the ergonomics and usability of the long hand-held tool such as the laparoscopic instrument in this study. To optimize efficiency in using these tools, the consideration of a better weight design is important and should not be neglected.

  13. Description of a 20 Kilohertz power distribution system

    Science.gov (United States)

    Hansen, I. G.

    1986-01-01

    A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution link; mulitphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

  14. A directed network of Greek and Roman mythology

    Science.gov (United States)

    Choi, Yeon-Mu; Kim, Hyun-Joo

    2007-08-01

    We construct a directed network using a dictionary of Greek and Roman mythology in which the nodes represent the entries listed in the dictionary and we make directional links from an entry to other entries that appear in its explanatory part. We find that this network is clearly not a random network but a directed scale-free network in which the distributions of out-degree and in-degree follow a power-law with exponents γout≈3.0 and γin≈2.5, respectively. Also we measure several quantities which describe the topological properties of the network and compare it to that of other real networks.

  15. LOG-NORMAL DISTRIBUTION OF COSMIC VOIDS IN SIMULATIONS AND MOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Russell, E.; Pycke, J.-R., E-mail: er111@nyu.edu, E-mail: jrp15@nyu.edu [Division of Science and Mathematics, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi (United Arab Emirates)

    2017-01-20

    Following up on previous studies, we complete here a full analysis of the void size distributions of the Cosmic Void Catalog based on three different simulation and mock catalogs: dark matter (DM), haloes, and galaxies. Based on this analysis, we attempt to answer two questions: Is a three-parameter log-normal distribution a good candidate to satisfy the void size distributions obtained from different types of environments? Is there a direct relation between the shape parameters of the void size distribution and the environmental effects? In an attempt to answer these questions, we find here that all void size distributions of these data samples satisfy the three-parameter log-normal distribution whether the environment is dominated by DM, haloes, or galaxies. In addition, the shape parameters of the three-parameter log-normal void size distribution seem highly affected by environment, particularly existing substructures. Therefore, we show two quantitative relations given by linear equations between the skewness and the maximum tree depth, and between the variance of the void size distribution and the maximum tree depth, directly from the simulated data. In addition to this, we find that the percentage of voids with nonzero central density in the data sets has a critical importance. If the number of voids with nonzero central density reaches ≥3.84% in a simulation/mock sample, then a second population is observed in the void size distributions. This second population emerges as a second peak in the log-normal void size distribution at larger radius.

  16. A digital elevation analysis: Spatially distributed flow apportioning algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Hyun; Kim, Kyung-Hyun [Pusan National University, Pusan(Korea); Jung, Sun-Hee [Korea Environment Institute, (Korea)

    2001-06-30

    A flow determination algorithm is proposed for the distributed hydrologic model. The advantages of a single flow direction scheme and multiple flow direction schemes are selectively considered to address the drawbacks of existing algorithms. A spatially varied flow apportioning factor is introduced in order to accommodate the accumulated area from upslope cells. The channel initiation threshold area(CIT) concept is expanded and integrated into the spatially distributed flow apportioning algorithm in order to delineate a realistic channel network. An application of a field example suggests that the linearly distributed flow apportioning scheme provides some advantages over existing approaches, such as the relaxation of over-dissipation problems near channel cells, the connectivity feature of river cells, the continuity of saturated areas and the negligence of the optimization of few parameters in existing algorithms. The effects of grid sizes are explored spatially as well as statistically. (author). 28 refs., 7 figs.

  17. Directing filtration to narrow molecular weight distribution of oligodextran in an enzymatic membrane reactor

    DEFF Research Database (Denmark)

    Su, Ziran; Luo, Jianquan; Pinelo, Manuel

    2018-01-01

    ) should be minimized to reduce accumulation of large oligodextran molecules on the membrane surface, which might diffuse through the membrane and thus broaden the Mw distribution of the products in the permeate. Both dextranase and dextran caused membrane irreversible fouling. The fouling caused...... product, hypersaline wastewater discharge and potential safety hazards. In this work, a novel enzymatic membrane reactor (EMR) system to produce oligodextran is proposed, whereby in-situ product recovery can be manipulated to control the Mw distribution of the resulting products. Results showed...... that the membrane material played an important role in the permeate flux and transmission of oligodextran. Among the tested membranes, a 20kDa polyethersulfone (PES) membrane was found to be optimal for building up the EMR, as it successfully controlled the oligodextran Mw within the desired range with a relatively...

  18. Distributional consequences of environmental taxes

    International Nuclear Information System (INIS)

    Klinge Jacobsen, H.; Birr-Pedersen, K.; Wier, M.

    2001-11-01

    Environmental taxes imposed on households have been introduced in many countries. However, few countries have reached the level of environmental taxation that is seen in Denmark today, although many are considering shifting the tax burden towards the consumption that is harming the environment. The total tax burden imposed on households in Denmark in the form of taxes on energy use of all kinds, water consumption and waste production, etc., is considerable. This paper analyses the individual taxes as well as the combination of all these taxes and duties related to environmental concerns, including taxes on heating, transport fuels, electricity, water, waste, plastic bags, registration of cars, annual car use, pesticides, etc. The distributional effect of taxes is examined in relation to household income, socio-economic class, residential location and family status. The shifting of the tax structure from high marginal income tax to consumption-based taxes, especially environmental taxes, might have distributional impacts amongst income groups which have not been considered part of the tax policy. The taxes are compared with respect to distributional impact. Do the effects of the different taxes vary to such an extent that this should be considered when designing tax policies? The hypothesis is that some environmental taxes associated with luxury income are less regressive than the average environmental tax. The results suggest that in Denmark taxes on petrol and registration duties for cars are progressive, whereas most other environmental taxes are regressive, especially the green taxes on water, retail containers and CO 2 . The distributional impacts are illustrated using household consumption survey data and data covering household expenditures on energy. The energy taxes and the more recently introduced green taxes are compared. The project is combining the direct and the indirect effect of taxes. The direct effect considers the taxes imposed directly on

  19. The influence of the directivity of musical instruments in a room

    DEFF Research Database (Denmark)

    Otondo, Felipe; Rindel, Jens Holger

    2004-01-01

    Measurements of the directivity of musical instruments are presented as part of the study of the influence of their representation in room acoustic simulations and auralizations. Pairs of measured and averaged directivities have been used both for room simulation comparisons and as a basis...... for listening experiments with auralizations. Room simulation results show a clear influence of the changes in the representation directivity on the distribution of acoustical parameters in the room. The results of the listening experiments with auralizations show that some changes produced by directivity...

  20. Visualizing Stress and Temperature Distribution During Elevated Temperature Deformation of IN-617 Using Nanomechanical Raman Spectroscopy

    Science.gov (United States)

    Zhang, Yang; Wang, Hao; Tomar, Vikas

    2018-04-01

    This work presents direct measurements of stress and temperature distribution during the mesoscale microstructural deformation of Inconel-617 (IN-617) during 3-point bending tests as a function of temperature. A novel nanomechanical Raman spectroscopy (NMRS)-based measurement platform was designed for simultaneous in situ temperature and stress mapping as a function of microstructure during deformation. The temperature distribution was found to be directly correlated to stress distribution for the analyzed microstructures. Stress concentration locations are shown to be directly related to higher heat conduction and result in microstructural hot spots with significant local temperature variation.

  1. On Design of Anisotropy Distributions, Applying Lamina Formulas for 2d Result Visualization

    DEFF Research Database (Denmark)

    Pedersen, Pauli; Pedersen, Niels Leergaard

    2015-01-01

    transformation for these practical quantities. The research background for optimal anisotropic constitutive matrices is shortly presented. Then design results are applied in a 2D visualization of optimized constitutive matrices, that are distributed in a finite element (FE) model where each element has......In rotational transformation of constitutive matrices, some practical quantities are often termed invariants, but the invariance relates to an unchanged reference direction. Rotating this reference direction, the practical quantities do change and this point is clarified with derived rotational...... a specific reference direction. The visualized distributions of physical quantities are; stiffest material direction, material stiffest longitudinal constitutive component, level of anisotropy, absolute or relative shear stiffness and orthotropy test....

  2. Probability distribution of long-run indiscriminate felling of trees in ...

    African Journals Online (AJOL)

    The study was undertaken to determine the probability distribution of Long-run indiscriminate felling of trees in northern senatorial district of Adamawa State. Specifically, the study focused on examining the future direction of indiscriminate felling of trees as well as its equilibrium distribution. A multi-stage and simple random ...

  3. Image quality of microcalcifications in digital breast tomosynthesis: Effects of projection-view distributions

    International Nuclear Information System (INIS)

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Goodsitt, Mitch; Carson, Paul L.; Hadjiiski, Lubomir; Schmitz, Andrea; Eberhard, Jeffrey W.; Claus, Bernhard E. H.

    2011-01-01

    Purpose: To analyze the effects of projection-view (PV) distribution on the contrast and spatial blurring of microcalcifications on the tomosynthesized slices (X-Y plane) and along the depth (Z) direction for the same radiation dose in digital breast tomosynthesis (DBT). Methods: A GE GEN2 prototype DBT system was used for acquisition of DBT scans. The system acquires PV images from 21 angles in 3 deg. increments over a ±30 deg. range. From these acquired PV images, the authors selected six subsets of PV images to simulate DBT of different angular ranges and angular increments. The number of PV images in each subset was fixed at 11 to simulate a constant total dose. These different PV distributions were subjectively divided into three categories: uniform group, nonuniform central group, and nonuniform extreme group with different angular ranges and angular increments. The simultaneous algebraic reconstruction technique (SART) was applied to each subset to reconstruct the DBT slices. A selective diffusion regularization method was employed to suppress noise. The image quality of microcalcifications in the reconstructed DBTs with different PV distributions was compared using the DBT scans of an American College of Radiology phantom and three human subjects. The contrast-to-noise ratio (CNR) and the full width at half maximum (FWHM) of the line profiles of microcalcifications within their in-focus DBT slices (parallel to detector plane) and the FWHMs of the interplane artifact spread function (ASF) in the Z-direction (perpendicular to detector plane) were used as image quality measures. Results: The results indicate that DBT acquired with a large angular range or, for an equal angular range,with a large fraction of PVs at large angles yielded superior ASF with smaller FWHM in the Z-direction. PV distributions with a narrow angular range or a large fraction of PVs at small angles had stronger interplane artifacts. In the X-Y focal planes, the effect of PV

  4. Intelligent Control and Operation of Distribution System

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad

    methodology to ensure efficient control and operation of the future distribution networks. The major scientific challenge is thus to develop control models and strategies to coordinate responses from widely distributed controllable loads and local generations. Detailed models of key Smart Grid (SG) elements...... in this direction but also benefit distribution system operators in the planning and development of the distribution network. The major contributions of this work are described in the following four stages: In the first stage, an intelligent Demand Response (DR) control architecture is developed for coordinating...... the key SG actors, namely consumers, network operators, aggregators, and electricity market entities. A key intent of the architecture is to facilitate market participation of residential consumers and prosumers. A Hierarchical Control Architecture (HCA) having primary, secondary, and tertiary control...

  5. Folliculin directs the formation of a Rab34-RILP complex to control the nutrient-dependent dynamic distribution of lysosomes.

    Science.gov (United States)

    Starling, Georgina P; Yip, Yan Y; Sanger, Anneri; Morton, Penny E; Eden, Emily R; Dodding, Mark P

    2016-06-01

    The spatial distribution of lysosomes is important for their function and is, in part, controlled by cellular nutrient status. Here, we show that the lysosome associated Birt-Hoge-Dubé (BHD) syndrome renal tumour suppressor folliculin (FLCN) regulates this process. FLCN promotes the peri-nuclear clustering of lysosomes following serum and amino acid withdrawal and is supported by the predominantly Golgi-associated small GTPase Rab34. Rab34-positive peri-nuclear membranes contact lysosomes and cause a reduction in lysosome motility and knockdown of FLCN inhibits Rab34-induced peri-nuclear lysosome clustering. FLCN interacts directly via its C-terminal DENN domain with the Rab34 effector RILP Using purified recombinant proteins, we show that the FLCN-DENN domain does not act as a GEF for Rab34, but rather, loads active Rab34 onto RILP We propose a model whereby starvation-induced FLCN association with lysosomes drives the formation of contact sites between lysosomes and Rab34-positive peri-nuclear membranes that restrict lysosome motility and thus promote their retention in this region of the cell. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  6. Measurement of leakage dose distribution from Crookes tube using imaging plate

    International Nuclear Information System (INIS)

    Fujibuchi, Toshioh; Obara, Satoshi; Inoue, Hajime; Kato, Hideyuki; Kobayashi, Ikuo; Hosoda, Masahiro

    2011-01-01

    Crookes tube is used on an educational site in the junior high school and the high school, etc. for the purpose to learn the character of cathode rays. When using the tube, X rays are generated, however, there is few example of confirming in which direction to scatter in detail. Understanding how the distribution of the leakage dose is important because of efficient exposure decrease. The distribution of X rays generated from Crookes tube was measured by arranging imaging plates in six surroundings to enclose Crookes tube. The electron collided with a metal target and X rays had extended backward. The dose was greatly different depending on the direction. When experimenting with Crookes tube, it is necessary to consider not only the dose but also distribution. (author)

  7. On-Line Detection of Distributed Attacks from Space-Time Network Flow Patterns

    National Research Council Canada - National Science Library

    Baras, J. S; Cardenas, A. A; Ramezani, V

    2003-01-01

    .... The directionality of the change in a network flow is assumed to have an objective or target. The particular problem of detecting distributed denial of service attacks from distributed observations is presented as a working framework...

  8. Performance Analysis of Polarization Modulated DirectDetection Optical CDMA Systems over Turbulent FSO LinksModeled by the Gamma-Gamma Distribution

    Directory of Open Access Journals (Sweden)

    Fan Bai

    2015-01-01

    Full Text Available This paper proposes a theoretical study to characterize the transmission of optical code division multiple access (CDMA systems deploying polarization shift keying (PolSK over a free space optical (FSO link under the impact of atmospheric turbulence. In our analysis, a novel transceiver architecture for atmospheric OCDMA FSO systems based on polarization modulation with direct detection is proposed and discussed. A detailed analytical model for PolSK-OCDMA systems over a turbulent FSO link is provided. Further, we derive a closed-form bit error ratio (BER and outage probability expressions, taking into account the multiple-access interference (MAI, optical noise and the atmospheric turbulence effect on the FSO link modeled by the Gamma-Gamma distribution. Finally, the results of this study show the most significant parameters that degrade the transmission performance of the PolSK-OCDMA signal over FSO links and indicate that the proposed approach offers improved bit error ratio (BER performances compared to the on-off-keying (OOK modulation scheme in the presence of turbulence.

  9. System for forecasting a reactor power distribution

    International Nuclear Information System (INIS)

    Motoda, Hiroshi; Nishizawa, Yasuo.

    1976-01-01

    Purpose: To dispense with frequent running of detector in a BWR type reactor and permit calculation of the prevailing value and forecast value of power distribution in a specified region in an on-line basis. Constitution: The prevailing power distribution P sub(OZ) (where Z indicates a position in the axial direction) at a given position is estimated by prevailing power distribution estimating means, and the average prevailing power distribution Q sub(OZ) in the core is estimated while making correction of a primary neutron distribution model by core average characteristic measuring means. Then, the estimated core average power distribution Q sub(Z) after alteration of the core flow rate or alteration of Xe concentration is estimated by core average power distribution estimating means. At this time, a forecast power distribution P sub(Z) in a specified region after alteration of the flow rate or alteration of the Xe concentration is calculated on the basis of a relation P sub(Z) = (Q sub(Z)/Q sub(OZ)) by using P sub(OZ), Q sub(OZ) and Q sub(Z). The above calculations are carried out in a short period of time by using a process computer. (Ikeda, J.)

  10. Direct visualization of the vortex distributions in a superconducting film with a Penrose array of magnetic pinning centers: Symmetry induced giant vortex state

    International Nuclear Information System (INIS)

    Kramer, R.B.G.; Silhanek, A.V.; Van de Vondel, J.; Raes, B.; Moshchalkov, V.V.

    2010-01-01

    Using scanning Hall probe microscopy a direct visualization of the flux distribution in a Pb film covering a fivefold Penrose array of Co dots is obtained. We demonstrate that stable vortex configurations can be found for fields H ∼ 0.8H 1 , H 1 and 1.6H 1 , where H 1 corresponds to one flux quantum per pinning site. The vortex pattern at 0.8H 1 corresponds to one vacancy in one of the vertices of the thin tiles whereas at 1.6H 1 the vortex structure can be associated with one interstitial vortex inside each thick tile. Strikingly, for H = 1.6H 1 interstitial and pinned vortices arrange themselves in ring-like structures ('vortex corrals') which favor the formation of a giant vortex state at their center.

  11. Two-dimensional potential and charge distributions of positive surface streamer

    International Nuclear Information System (INIS)

    Tanaka, Daiki; Matsuoka, Shigeyasu; Kumada, Akiko; Hidaka, Kunihiko

    2009-01-01

    Information on the potential and the field profile along a surface discharge is required for quantitatively discussing and clarifying the propagation mechanism. The sensing technique with a Pockels crystal has been developed for directly measuring the potential and electric field distribution on a dielectric material. In this paper, the Pockels sensing system consists of a pulse laser and a CCD camera for measuring the instantaneous two-dimensional potential distribution on a 25.4 mm square area with a 50 μm sampling pitch. The temporal resolution is 3.2 ns which is determined by the pulse width of the laser emission. The transient change in the potential distribution of a positive surface streamer propagating in atmospheric air is measured with this system. The electric field and the charge distributions are also calculated from the measured potential profile. The propagating direction component of the electric field near the tip of the propagating streamer reaches 3 kV mm -1 . When the streamer stops, the potential distribution along a streamer forms an almost linear profile with the distance from the electrode, and its gradient is about 0.5 kV mm -1 .

  12. Estimates of rates and errors for measurements of direct-γ and direct-γ + jet production by polarized protons at RHIC

    International Nuclear Information System (INIS)

    Beddo, M.E.; Spinka, H.; Underwood, D.G.

    1992-01-01

    Studies of inclusive direct-γ production by pp interactions at RHIC energies were performed. Rates and the associated uncertainties on spin-spin observables for this process were computed for the planned PHENIX and STAR detectors at energies between √s = 50 and 500 GeV. Also, rates were computed for direct-γ + jet production for the STAR detector. The goal was to study the gluon spin distribution functions with such measurements. Recommendations concerning the electromagnetic calorimeter design and the need for an endcap calorimeter for STAR are made

  13. Halo-independent direct detection of momentum-dependent dark matter

    DEFF Research Database (Denmark)

    Cherry, J. F.; Frandsen, M. T.; Shoemaker, I. M.

    2014-01-01

    We show that the momentum dependence of dark matter interactions with nuclei can be probed in direct detection experiments without knowledge of the dark matter velocity distribution. This is one of the few properties of DM microphysics that can be determined with direct detection alone, given...... a signal of dark matter in multiple direct detection experiments with different targets. Long-range interactions arising from the exchange of a light mediator are one example of momentum-dependent DM. For data produced from the exchange of a massless mediator we find for example that the mediator mass can...

  14. Scanner for the recording of radioactivity distribution

    International Nuclear Information System (INIS)

    Seebeck, U.

    1975-01-01

    In a scintiscanner comprising an upper measuring head and a lower measuring head and associated write heads, the activity distribution measured by the lower measuring head is recorded in the form of a mirror-image if the write heads in the two recording directions are moved in the same direction with respect to each other. However, if the write heads in the one recording direction are displaced opposite to each other, a correct recording is obtained, but it is then very difficult to compare the scintigrams recorded by the measuring heads. The invention describes a simple mechanical device by means of which the write heads can be moved in the same or in the opposite direction with respect to each other. (auth)

  15. Current distribution tomography for determination of internal current density distributions

    International Nuclear Information System (INIS)

    Gailey, P.C.

    1993-01-01

    A method is presented for determination of current densities inside a cylindrical object using measurements of the magnetic fields outside the object. The cross section of the object is discretized with the current assumed constant over each defined region. Magnetic fields outside the object are related to the internal current densities through a geometry matrix which can be inverted to yield a solution for the current densities in terms of the measured fields. The primary limitation of this technique results from singularities in the geometry matrix that arise due to cylindrical symmetry of the problem. Methods for circumventing the singularities to obtain information about the distribution of current densities are discussed. This process of current distribution tomography is designed to determine internal body current densities using measurements of the external magnetic field distribution. It is non-invasive, and relatively simple to implement. Although related to a more general study of magnetic imaging which has been used to investigate endogenous currents in the brain and other parts of the body, it is restricted to currents either applied directly or induced by exposure to an external field. The research is related to public concern about the possibility of health effects resulting from exposure to power frequency electric and magnetic fields

  16. Distribution and derivation of white-winged dove harvests in Texas

    KAUST Repository

    Collier, Bret A.; Skow, Kevin L.; Kremer, Shelly R.; Mason, Corey D.; Snelgrove, Robert T.; Calhoun, Kirby W.

    2012-01-01

    Band recoveries provide requisite data for evaluating the spatial distribution of harvest relative to the distribution of breeding stocks for a wide variety of migratory species. We used direct and indirect band-recovery data to evaluate the distribution and derivation of harvest of white-winged doves (Zenaida asiatica) banded before hunting season in 3 distinct strata in Texas, USA, during 2007-2010. We banded 60,742 white-winged doves during 2007-2010, and based on 2,458 harvest recoveries, the majority (>95%) of white-winged dove harvest occurred during the first 2 months of the hunting season (Sep-Oct). Juvenile white-winged doves represented a greater percentage of the direct recoveries than adults across all strata (north = 80%, central = 69%, south = 82%) and the majority of direct band recoveries (north = 75%, central = 90%, south = 78%) occurred within the original banding strata. Age-specific weighting factors and harvest derivation indicated that both juvenile and adult harvest were highest within the strata of original banding. Harvest distribution data corrected for band-reporting rates indicated high fidelity of white-winged doves to specific geographic strata, with little interplay between strata. Our results suggest that population vital-rate estimates for survival and harvest for use in future Adaptive Harvest Management should focus on stock-specific levels. © 2012 The Wildlife Society.

  17. Distribution and derivation of white-winged dove harvests in Texas

    KAUST Repository

    Collier, Bret A.

    2012-04-25

    Band recoveries provide requisite data for evaluating the spatial distribution of harvest relative to the distribution of breeding stocks for a wide variety of migratory species. We used direct and indirect band-recovery data to evaluate the distribution and derivation of harvest of white-winged doves (Zenaida asiatica) banded before hunting season in 3 distinct strata in Texas, USA, during 2007-2010. We banded 60,742 white-winged doves during 2007-2010, and based on 2,458 harvest recoveries, the majority (>95%) of white-winged dove harvest occurred during the first 2 months of the hunting season (Sep-Oct). Juvenile white-winged doves represented a greater percentage of the direct recoveries than adults across all strata (north = 80%, central = 69%, south = 82%) and the majority of direct band recoveries (north = 75%, central = 90%, south = 78%) occurred within the original banding strata. Age-specific weighting factors and harvest derivation indicated that both juvenile and adult harvest were highest within the strata of original banding. Harvest distribution data corrected for band-reporting rates indicated high fidelity of white-winged doves to specific geographic strata, with little interplay between strata. Our results suggest that population vital-rate estimates for survival and harvest for use in future Adaptive Harvest Management should focus on stock-specific levels. © 2012 The Wildlife Society.

  18. The impact of baryons on the direct detection of dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, Chris [Department of Physics, University of North Florida, Jacksonville, FL 32224 (United States); Savage, Christopher; Freese, Katherine [Nordita, KTH Royal Institute of Technology and Stockholm University, SE-106 91 Stockholm (Sweden); Valluri, Monica [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Stinson, Gregory S. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Bailin, Jeremy, E-mail: ckelso@unf.edu, E-mail: chris@savage.name, E-mail: mvalluri@umich.edu, E-mail: ktfreese@umich.edu, E-mail: stinson@mpia.de, E-mail: jbailin@ua.edu [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States)

    2016-08-01

    The spatial and velocity distributions of dark matter particles in the Milky Way Halo affect the signals expected to be observed in searches for dark matter. Results from direct detection experiments are often analyzed assuming a simple isothermal distribution of dark matter, the Standard Halo Model (SHM). Yet there has been skepticism regarding the validity of this simple model due to the complicated gravitational collapse and merger history of actual galaxies. In this paper we compare the SHM to the results of cosmological hydrodynamical simulations of galaxy formation to investigate whether or not the SHM is a good representation of the true WIMP distribution in the analysis of direct detection data. We examine two Milky Way-like galaxies from the MaGICC cosmological simulations (a) with dark matter only and (b) with baryonic physics included. The inclusion of baryons drives the shape of the DM halo to become more spherical and makes the velocity distribution of dark matter particles less anisotropic especially at large heliocentric velocities, thereby making the SHM a better fit. We also note that we do not find a significant disk-like rotating dark matter component in either of the two galaxy halos with baryons that we examine, suggesting that dark disks are not a generic prediction of cosmological hydrodynamical simulations. We conclude that in the Solar neighborhood, the SHM is in fact a good approximation to the true dark matter distribution in these cosmological simulations (with baryons) which are reasonable representations of the Milky Way, and hence can also be used for the purpose of dark matter direct detection calculations.

  19. Direct determination of platinum group elements and their distributions in geological and environmental samples at the ng g{sup -1} level using LA-ICP-IDMS

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, Sergei F.; Heumann, Klaus G. [Johannes Gutenberg-University Mainz, Institute of Inorganic Chemistry and Analytical Chemistry, Mainz (Germany)

    2005-10-01

    Laser ablation inductively coupled plasma isotope dilution mass spectrometry (LA-ICP-IDMS) was applied to the direct and simultaneous determination of the platinum group elements (PGEs) Pt, Pd, Ru, and Ir in geological and environmental samples. A special laser ablation system with high ablation rates was used, along with sector field ICP-MS. Special attention was paid to deriving the distributions of PGEs in the pulverized samples. IDMS could not be applied to the (mono-isotopic) Rh, but the similar ablation behavior of Ru and Rh allowed Rh to be simultaneously determined via relative sensitivity coefficients. The laser ablation process produces hardly any oxide ions (which usually cause interference in PGE analysis with liquid sample injection), so the ICP-MS can be run in its low mass resolution but high-sensitivity mode. The detection limits obtained for the geological samples were 0.16 ng g{sup -1}, 0.14 ng g{sup -1}, 0.08 ng g{sup -1}, 0.01 ng g{sup -1} and 0.06 ng g{sup -1} for Ru, Rh, Pd, Ir and Pt, respectively. LA-ICP-IDMS was applied to different geological reference materials (TDB-1, WGB-1, UMT-1, WMG-1, SARM-7) and the road dust reference material BCR-723, which are only certified for some of the PGEs. Comparisons with certified values as well as with indicative values from the literature demonstrated the validity of the LA-ICP-IDMS method. The PGE concentrations in subsamples of the road dust reference material correspond to a normal distribution, whereas the distributions in the geological reference materials TDB-1, WGB-1, UMT-1, WMG-1, and SARM-7 are more complex. For example, in the case of Ru, a logarithmic normal distribution best fits the analyzed concentrations in TDB-1 subsamples, whereas a pronounced nugget effect was found for Pt in most geological samples. (orig.)

  20. The ATLAS distributed analysis system

    International Nuclear Information System (INIS)

    Legger, F

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  1. The ATLAS distributed analysis system

    Science.gov (United States)

    Legger, F.; Atlas Collaboration

    2014-06-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  2. Smart Distribution Boxes, Complete Energy Management

    Energy Technology Data Exchange (ETDEWEB)

    Platise, Uros

    2010-09-15

    Present households demand side management implementations are turning conventional appliances into smart ones to support auto demand (AutoDR) response function. Present concept features a direct link between the power meters and appliances. In this paper new concept and example of implementation of a so-called Smart Distribution Box (SmartDB) is represented for complete energy and power management. SmartDBs, as an intermediate layer, are extending smart grid power meter functionality to support AutoDR with fast and guaranteed response times, distributed power sources, and besides provide full control over energy management and extra safety functions to the consumers.

  3. Distributed model predictive control made easy

    CERN Document Server

    Negenborn, Rudy

    2014-01-01

    The rapid evolution of computer science, communication, and information technology has enabled the application of control techniques to systems beyond the possibilities of control theory just a decade ago. Critical infrastructures such as electricity, water, traffic and intermodal transport networks are now in the scope of control engineers. The sheer size of such large-scale systems requires the adoption of advanced distributed control approaches. Distributed model predictive control (MPC) is one of the promising control methodologies for control of such systems.   This book provides a state-of-the-art overview of distributed MPC approaches, while at the same time making clear directions of research that deserve more attention. The core and rationale of 35 approaches are carefully explained. Moreover, detailed step-by-step algorithmic descriptions of each approach are provided. These features make the book a comprehensive guide both for those seeking an introduction to distributed MPC as well as for those ...

  4. Balanced distributed coding of omnidirectional images

    Science.gov (United States)

    Thirumalai, Vijayaraghavan; Tosic, Ivana; Frossard, Pascal

    2008-01-01

    This paper presents a distributed coding scheme for the representation of 3D scenes captured by stereo omni-directional cameras. We consider a scenario where images captured from two different viewpoints are encoded independently, with a balanced rate distribution among the different cameras. The distributed coding is built on multiresolution representation and partitioning of the visual information in each camera. The encoder transmits one partition after entropy coding, as well as the syndrome bits resulting from the channel encoding of the other partition. The decoder exploits the intra-view correlation and attempts to reconstruct the source image by combination of the entropy-coded partition and the syndrome information. At the same time, it exploits the inter-view correlation using motion estimation between images from different cameras. Experiments demonstrate that the distributed coding solution performs better than a scheme where images are handled independently, and that the coding rate stays balanced between encoders.

  5. Dispersion Theory of Direct Nuclear Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, I. S. [Institute Of Theoretical And Experimental Physics, Moscow, USSR (Russian Federation)

    1963-01-15

    The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

  6. Dispersion Theory of Direct Nuclear Reactions

    International Nuclear Information System (INIS)

    Shapiro, I.S.

    1963-01-01

    The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

  7. Self-consistent particle distribution of a bunched beam in RF field

    CERN Document Server

    Batygin, Y K

    2002-01-01

    An analytical solution for the self-consistent particle equilibrium distribution in an RF field with transverse focusing is found. The solution is attained in the approximation of a high brightness beam. The distribution function in phase space is determined as a stationary function of the energy integral. Equipartitioning of the beam distribution between degrees of freedom follows directly from the choice of the stationary distribution function. Analytical expressions for r-z equilibrium beam profile and maximum beam current in RF field are obtained.

  8. Angular distributions as lifetime probes

    Energy Technology Data Exchange (ETDEWEB)

    Dror, Jeff Asaf; Grossman, Yuval [Department of Physics, LEPP, Cornell University,Ithaca, NY 14853 (United States)

    2014-06-27

    If new TeV scale particles are discovered, it will be important to determine their width. There is, however, a problematic region, where the width is too small to be determined directly, and too large to generate a secondary vertex. For a collection of colored, spin polarized particles, hadronization depolarizes the particles prior to their decay. The amount of depolarization can be used to probe the lifetime in the problematic region. In this paper we apply this method to a realistic scenario of a top-like particle that can be produced at the LHC. We study how depolarization affects the angular distributions of the decay products and derive an equation for the distributions that is sensitive to the lifetime.

  9. ABOUT DIRECT SALES IN THE WORLD, EUROPE AND ROMANIA

    Directory of Open Access Journals (Sweden)

    CLAUDIA ISAC

    2011-01-01

    Full Text Available Direct sale represents a modern product distribution system directly to consumers, generally, directly to their homes, to their workplace or other places, beside retail shops. The best known type of direct sale, the Network Marketing or Multilevel Marketing implies the existence of a network of distributors which earn income from selling on commission, to which they add the trade markup. This paper is based upon the analysis of these types of sales starting with the study of specialized literature especially by foreign authors, mainly Americans, with the analysis of statistical data presented by several organizations such as SELDIA (The European Direct Selling Association, MLM International Romania, ACVD (Association of Direct Selling Companies in Romania, as well as the legal regulations within this field. In conclusion, the paper presents an interesting comparison of the sales and structure volume between the Europe and Romania.

  10. Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

    Science.gov (United States)

    Chen, Yue; Cunningham, Gregory; Henderson, Michael

    2016-09-01

    This study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Second, using a newly developed proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors ˜ 5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. This study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.

  11. Establishing the kinetics of ballistic-to-diffusive transition using directional statistics

    Science.gov (United States)

    Liu, Pai; Heinson, William R.; Sumlin, Benjamin J.; Shen, Kuan-Yu; Chakrabarty, Rajan K.

    2018-04-01

    We establish the kinetics of ballistic-to-diffusive (BD) transition observed in two-dimensional random walk using directional statistics. Directional correlation is parameterized using the walker's turning angle distribution, which follows the commonly adopted wrapped Cauchy distribution (WCD) function. During the BD transition, the concentration factor (ρ) governing the WCD shape is observed to decrease from its initial value. We next analytically derive the relationship between effective ρ and time, which essentially quantifies the BD transition rate. The prediction of our kinetic expression agrees well with the empirical datasets obtained from correlated random walk simulation. We further connect our formulation with the conventionally used scaling relationship between the walker's mean-square displacement and time.

  12. Simulated Milky Way analogues: implications for dark matter direct searches

    Science.gov (United States)

    Bozorgnia, Nassim; Calore, Francesca; Schaller, Matthieu; Lovell, Mark; Bertone, Gianfranco; Frenk, Carlos S.; Crain, Robert A.; Navarro, Julio F.; Schaye, Joop; Theuns, Tom

    2016-05-01

    We study the implications of galaxy formation on dark matter direct detection using high resolution hydrodynamic simulations of Milky Way-like galaxies simulated within the EAGLE and APOSTLE projects. We identify Milky Way analogues that satisfy observational constraints on the Milky Way rotation curve and total stellar mass. We then extract the dark matter density and velocity distribution in the Solar neighbourhood for this set of Milky Way analogues, and use them to analyse the results of current direct detection experiments. For most Milky Way analogues, the event rates in direct detection experiments obtained from the best fit Maxwellian distribution (with peak speed of 223-289 km/s) are similar to those obtained directly from the simulations. As a consequence, the allowed regions and exclusion limits set by direct detection experiments in the dark matter mass and spin-independent cross section plane shift by a few GeV compared to the Standard Halo Model, at low dark matter masses. For each dark matter mass, the halo-to-halo variation of the local dark matter density results in an overall shift of the allowed regions and exclusion limits for the cross section. However, the compatibility of the possible hints for a dark matter signal from DAMA and CDMS-Si and null results from LUX and SuperCDMS is not improved.

  13. Impact of size and distribution of installed PV power in E-W direction on the level in which selected consumers’ energy needs were met

    Directory of Open Access Journals (Sweden)

    Necka Krzysztof

    2018-01-01

    Full Text Available The aim of the study was to analyse the energy needs of selected consumers and to select the PV installed capacity in the east and west panels orientation (E-W. The analysis was carried out for two variants. The first concerned the impact of the installation power of a PV source on the contracted power in its symmetric east and west position. The second variant was the result of previous observations and studies of the authors of this paper. Thus, in this variant, the unbalanced power of PV E-W in relation to the S azimuth has been analyzed, taking into account the characteristics of the recipients' needs and the variation of the PV power installed. The analyses show that an increase in meeting the energy demand for two of the tested plants at symmetrical power distribution to the east and west occurred only when the installed power was increased to the level of approx. 1.4-1.6 of the contracted power. However, the power distribution in the E-W direction has a very strong effect on the energy amount that is generated in the power plant and cannot be used due to the lack of demand in the plant.

  14. Near-field probing of photonic crystal directional couplers

    DEFF Research Database (Denmark)

    Volkov, V. S.; Bozhevolnyi, S. I.; Borel, Peter Ingo

    2006-01-01

    We report the design, fabrication and characterization of a photonic crystal directional with a size of ~20 x 20 mm2 fabricated in silicon-on-insulator material. Using a scanning near-field optical microscope we demonstrate a high coupling efficiency for TM polarized light at telecom wavelengths....... By comparing the near-field optical images recorded in and after the directional coupler area, the features of light distribution are analyzed. Finally, the scanning near-field optical microscope observations are found to be in agreement with the transmission measurements conducted with the same sample....

  15. Angular distributions of sputtered particles from NiTi alloy

    International Nuclear Information System (INIS)

    Neshev, I.; Hamishkeev, V.; Chernysh, V.S.; Postnikov, S.; Mamaev, B.

    1993-01-01

    The angular distributions of sputtered Ni and Ti from a polycrystalline NiTi (50-50%) alloy are investigated by Auger electron spectroscopy and Rutherford backscattering spectroscopy. A difference in the angular distributions is observed with Ni being sputtered preferentially near the surface normal. A computer program for the calculation of the angular distributions of constituents sputtered from binary targets is created and used. The mechanisms responsible for the observed differences in the angular distributions are discussed. It is found that the collisional cascade theory is not directly applicable to the results of the constituents' angular distributions obtained in the presence of oxygen. The fitted coefficients of bombardment-induced segregation are found to be greater than the experimentally obtained ones. (author)

  16. Power Quality in DC Power Distribution Systems and Microgrids

    Directory of Open Access Journals (Sweden)

    Stephen Whaite

    2015-05-01

    Full Text Available This review paper discusses power quality considerations for direct current (DC electric power distribution systems, particularly DC microgrids. First, four selected sample DC architectures are discussed to provide motivation for the consideration of power quality in DC systems. Second, a brief overview of power quality challenges in conventional alternating current (AC distribution systems is given to establish the field of power quality. Finally, a survey of literature addressing power quality issues in DC systems is presented, and necessary power quality considerations in DC distribution system design and operation are discussed.

  17. Quantum Secure Direct Intercommunication with Superdense Coding and Entanglement Swapping

    International Nuclear Information System (INIS)

    Huang Dazu; Guo Ying; Zeng Guihua

    2008-01-01

    A quantum secure direct intercommunication scheme is proposed to exchange directly the communicators' secret messages by making use of swapping entanglement of Bell states. It has great capacity to distribute the secret messages since these messages have been imposed on high-dimensional Bell states via the local unitary operations with superdense coding. The security is ensured by the secure transmission of the travel sequences and the application of entanglement swapping

  18. Direct Estimation of Power Distribution in Reactors for Nuclear Thermal Space Propulsion

    Science.gov (United States)

    Aldemir, Tunc; Miller, Don W.; Burghelea, Andrei

    2004-02-01

    A recently proposed constant temperature power sensor (CTPS) has the capability to directly measure the local power deposition rate in nuclear reactor cores proposed for space thermal propulsion. Such a capability reduces the uncertainties in the estimated power peaking factors and hence increases the reliability of the nuclear engine. The CTPS operation is sensitive to the changes in the local thermal conditions. A procedure is described for the automatic on-line calibration of the sensor through estimation of changes in thermal .conditions.

  19. Advance directives: survey of primary care patients.

    Science.gov (United States)

    O'Sullivan, Rory; Mailo, Kevin; Angeles, Ricardo; Agarwal, Gina

    2015-04-01

    To establish the prevalence of patients with advance directives in a family practice, and to describe patients' perspectives on a family doctor's role in initiating discussions about advance directives. A self-administered patient questionnaire. A busy urban family medicine teaching clinic in Hamilton, Ont. A convenience sample of adult patients attending the clinic over the course of a typical business week. The prevalence of advance directives in the patient population was determined, and the patients' expectations regarding the role of their family doctors were elucidated. The survey population consisted of 800 participants (a response rate of 72.5%) well distributed across age groups; 19.7% had written advance directives and 43.8% had previously discussed the topic of advance directives, but only 4.3% of these discussions had occurred with family doctors. In 5.7% of cases, a family physician had raised the issue; 72.3% of respondents believed patients should initiate the discussion. Patients who considered advance directives extremely important were significantly more likely to want their family doctors to start the conversation (odds ratio 3.98; P < .05). Advance directives were not routinely addressed in the family practice. Most patients preferred to initiate the discussion of advance directives. However, patients who considered the subject extremely important wanted their family doctors to initiate the discussion. Copyright© the College of Family Physicians of Canada.

  20. Directed emission of CdSe nanoplatelets originating from strongly anisotropic 2D electronic structure

    Science.gov (United States)

    Scott, Riccardo; Heckmann, Jan; Prudnikau, Anatol V.; Antanovich, Artsiom; Mikhailov, Aleksandr; Owschimikow, Nina; Artemyev, Mikhail; Climente, Juan I.; Woggon, Ulrike; Grosse, Nicolai B.; Achtstein, Alexander W.

    2017-12-01

    Intrinsically directional light emitters are potentially important for applications in photonics including lasing and energy-efficient display technology. Here, we propose a new route to overcome intrinsic efficiency limitations in light-emitting devices by studying a CdSe nanoplatelets monolayer that exhibits strongly anisotropic, directed photoluminescence. Analysis of the two-dimensional k-space distribution reveals the underlying internal transition dipole distribution. The observed directed emission is related to the anisotropy of the electronic Bloch states governing the exciton transition dipole moment and forming a bright plane. The strongly directed emission perpendicular to the platelet is further enhanced by the optical local density of states and local fields. In contrast to the emission directionality, the off-resonant absorption into the energetically higher 2D-continuum of states is isotropic. These contrasting optical properties make the oriented CdSe nanoplatelets, or superstructures of parallel-oriented platelets, an interesting and potentially useful class of semiconductor-based emitters.

  1. Measuring Geographic Distribution of Economic Activity in Nigeria ...

    African Journals Online (AJOL)

    USER

    For example, the outcome of this study could help further development of ... selection of the years was informed by the availability of gridded population data. The dataset .... slight difference in the directional distribution of the economic activity.

  2. Estimating the temporal distribution of exposure-related cancers

    International Nuclear Information System (INIS)

    Carter, R.L.; Sposto, R.; Preston, D.L.

    1993-09-01

    The temporal distribution of exposure-related cancers is relevant to the study of carcinogenic mechanisms. Statistical methods for extracting pertinent information from time-to-tumor data, however, are not well developed. Separation of incidence from 'latency' and the contamination of background cases are two problems. In this paper, we present methods for estimating both the conditional distribution given exposure-related cancers observed during the study period and the unconditional distribution. The methods adjust for confounding influences of background cases and the relationship between time to tumor and incidence. Two alternative methods are proposed. The first is based on a structured, theoretically derived model and produces direct inferences concerning the distribution of interest but often requires more-specialized software. The second relies on conventional modeling of incidence and is implemented through readily available, easily used computer software. Inferences concerning the effects of radiation dose and other covariates, however, are not always obtainable directly. We present three examples to illustrate the use of these two methods and suggest criteria for choosing between them. The first approach was used, with a log-logistic specification of the distribution of interest, to analyze times to bone sarcoma among a group of German patients injected with 224 Ra. Similarly, a log-logistic specification was used in the analysis of time to chronic myelogenous leukemias among male atomic-bomb survivors. We used the alternative approach, involving conventional modeling, to estimate the conditional distribution of exposure-related acute myelogenous leukemias among male atomic-bomb survivors, given occurrence between 1 October 1950 and 31 December 1985. All analyses were performed using Poisson regression methods for analyzing grouped survival data. (J.P.N.)

  3. Distribution functions of sections and projections of convex bodies

    OpenAIRE

    Kim, Jaegil; Yaskin, Vladyslav; Zvavitch, Artem

    2015-01-01

    Typically, when we are given the section (or projection) function of a convex body, it means that in each direction we know the size of the central section (or projection) perpendicular to this direction. Suppose now that we can only get the information about the sizes of sections (or projections), and not about the corresponding directions. In this paper we study to what extent the distribution function of the areas of central sections (or projections) of a convex body can be used to derive ...

  4. Sustained Release of a Watermgoluble tiring from Directly ...

    African Journals Online (AJOL)

    Sustained Release of a Watermgoluble tiring from Directly Compressed Okra Gum Matrix. Tablets. Val). Mill, MA. Gilllllbll'ifl'l' AND KT. ... in near noromorder release of aspirin from the matrix tablets. The results indicate that okra gum is .... porous structure including alteration of the shape and size distribution of the pores.

  5. Analytic degree distributions of horizontal visibility graphs mapped from unrelated random series and multifractal binomial measures

    Science.gov (United States)

    Xie, Wen-Jie; Han, Rui-Qi; Jiang, Zhi-Qiang; Wei, Lijian; Zhou, Wei-Xing

    2017-08-01

    Complex network is not only a powerful tool for the analysis of complex system, but also a promising way to analyze time series. The algorithm of horizontal visibility graph (HVG) maps time series into graphs, whose degree distributions are numerically and analytically investigated for certain time series. We derive the degree distributions of HVGs through an iterative construction process of HVGs. The degree distributions of the HVG and the directed HVG for random series are derived to be exponential, which confirms the analytical results from other methods. We also obtained the analytical expressions of degree distributions of HVGs and in-degree and out-degree distributions of directed HVGs transformed from multifractal binomial measures, which agree excellently with numerical simulations.

  6. Effective distributions of quasiparticles for thermal photons

    Science.gov (United States)

    Monnai, Akihiko

    2015-07-01

    It has been found in recent heavy-ion experiments that the second and the third flow harmonics of direct photons are larger than most theoretical predictions. In this study, I construct effective parton phase-space distributions with in-medium interaction using quasiparticle models so that they are consistent with a lattice QCD equation of state. Then I investigate their effects on thermal photons using a hydrodynamic model. Numerical results indicate that elliptic flow and transverse momentum spectra are modified by the corrections to Fermi-Dirac and Bose-Einstein distributions.

  7. Method and apparatus for anti-islanding protection of distributed generations

    Science.gov (United States)

    Ye, Zhihong; John, Vinod; Wang, Changyong; Garces, Luis Jose; Zhou, Rui; Li, Lei; Walling, Reigh Allen; Premerlani, William James; Sanza, Peter Claudius; Liu, Yan; Dame, Mark Edward

    2006-03-21

    An apparatus for anti-islanding protection of a distributed generation with respect to a feeder connected to an electrical grid is disclosed. The apparatus includes a sensor adapted to generate a voltage signal representative of an output voltage and/or a current signal representative of an output current at the distributed generation, and a controller responsive to the signals from the sensor. The controller is productive of a control signal directed to the distributed generation to drive an operating characteristic of the distributed generation out of a nominal range in response to the electrical grid being disconnected from the feeder.

  8. Distribution of model-based multipoint heterogeneity lod scores.

    Science.gov (United States)

    Xing, Chao; Morris, Nathan; Xing, Guan

    2010-12-01

    The distribution of two-point heterogeneity lod scores (HLOD) has been intensively investigated because the conventional χ(2) approximation to the likelihood ratio test is not directly applicable. However, there was no study investigating th e distribution of the multipoint HLOD despite its wide application. Here we want to point out that, compared with the two-point HLOD, the multipoint HLOD essentially tests for homogeneity given linkage and follows a relatively simple limiting distribution ½χ²₀+ ½χ²₁, which can be obtained by established statistical theory. We further examine the theoretical result by simulation studies. © 2010 Wiley-Liss, Inc.

  9. Ion distributions in the Earth's foreshock upstream from the bow shock

    Science.gov (United States)

    Fuselier, S. A.

    1995-01-01

    A variety of suprathermal and energetic ion distributions are found upstream from shocks. Some distributions, such as field-aligned beams, are generated directly at the shock either through reflection processes or through leakage from the hotter downstream region. Other distributions, such as intermediate distributions, evolve from these parent distributions through wave-particle interactions. This paper reviews our current understanding of the creation and evolution of suprathermal distributions at shocks. Examples of suprathermal ion distributions are taken from observations at the Earth's bow shock. Particular emphasis is placed on the creation of field-aligned beams and specularly reflected ion distributions and on the evolution of these distributions in the Earth's ion foreshock. However, the results from this heavily studied region are applicable to interplanetary shocks, bow shocks at other planets, and comets.

  10. Distributed-Memory Fast Maximal Independent Set

    Energy Technology Data Exchange (ETDEWEB)

    Kanewala Appuhamilage, Thejaka Amila J.; Zalewski, Marcin J.; Lumsdaine, Andrew

    2017-09-13

    The Maximal Independent Set (MIS) graph problem arises in many applications such as computer vision, information theory, molecular biology, and process scheduling. The growing scale of MIS problems suggests the use of distributed-memory hardware as a cost-effective approach to providing necessary compute and memory resources. Luby proposed four randomized algorithms to solve the MIS problem. All those algorithms are designed focusing on shared-memory machines and are analyzed using the PRAM model. These algorithms do not have direct efficient distributed-memory implementations. In this paper, we extend two of Luby’s seminal MIS algorithms, “Luby(A)” and “Luby(B),” to distributed-memory execution, and we evaluate their performance. We compare our results with the “Filtered MIS” implementation in the Combinatorial BLAS library for two types of synthetic graph inputs.

  11. Prospect for the development of salted egg agro industry: an analysis on marketing distribution aspect

    Science.gov (United States)

    Sumekar, W.; Al-Baarri, A. N.; Kurnianto, E.

    2018-01-01

    Marketing distribution is an important of the strategy in business development in agroindustries. The aim of the research was to introduce marketing (distribution pattern, margin and marketing efficiency) at the salted egg agro industries in Brebes Regency. Survey method had been conducted on 52 salted egg agro industries which had active PIRT certificate. The data collection was conducted by means of interview and observation. Descriptive analysis was used to determine the marketing distribution of salted eggs. Marketing efficiency was obtained by calculating marketing margin and farmer share. The results show that the salted egg agro industries implemented two marketing distribution patterns; direct marketing pattern (consumer→producers) and indirect marketing pattern (producer→retailer→consumer). The number of the salted egg agro industries which apply indirect marketing pattern is 57.69%. The implementation of direct and indirect marketing patterns was classified as efficient according to the farmer’s share values of 87.13% and 78.21%. It can be recommended the direct marketing.

  12. Risk of viral acute gastrointestinal illness from non-disinfected drinking water distribution systems

    Science.gov (United States)

    Acute gastrointestinal illness (AGI) resulting from pathogens directly entering the piping of drinking water distribution systems is insufficiently understood. Here, we estimate AGI incidence attributable to virus intrusions into non-disinfecting municipal distribution systems. Viruses were enumerat...

  13. Invertebrate distribution patterns and river typology for the implementation of the water framework directive in Martinique, French Lesser Antilles

    Directory of Open Access Journals (Sweden)

    Bernadet C.

    2013-03-01

    Full Text Available Over the past decade, Europe’s Water Framework Directive provided compelling reasons for developing tools for the biological assessment of freshwater ecosystem health in member States. Yet, the lack of published study for Europe’s overseas regions reflects minimal knowledge of the distribution patterns of aquatic species in Community’s outermost areas. Benthic invertebrates (84 taxa and land-cover, physical habitat and water chemistry descriptors (26 variables were recorded at fifty-one stations in Martinique, French Lesser Antilles. Canonical Correspondence Analysis and Ward’s algorithm were used to bring out patterns in community structure in relation to environmental conditions, and variation partitioning was used to specify the influence of geomorphology and anthropogenic disturbance on invertebrate communities. Species richness decreased from headwater to lowland streams, and species composition changed from northern to southern areas. The proportion of variation explained by geomorphological variables was globally higher than that explained by anthropogenic variables. Geomorphology and land cover played key roles in delineating ecological sub-regions for the freshwater biota. Despite this and the small surface area of Martinique (1080 km2, invertebrate communities showed a clear spatial turnover in composition and biological traits (e.g., insects, crustaceans and molluscs in relation to natural conditions.

  14. Solar Wind Halo Formation by the Scattering of the Strahl via Direct Cluster/PEACE Observations of the 3D Velocity Distribution Function

    Science.gov (United States)

    Figueroa-Vinas, Adolfo; Gurgiolo, Chris A.; Nieves-Chinchilla, Teresa; Goldstein, Melvyn L.

    2010-01-01

    It has been suggested by a number of authors that the solar wind electron halo can be formed by the scattering of the strahl. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions) a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a very limited energy range. When the magnetic field is well off the nominal solar wind flow direction such filaments are inconsistent with any local forces and are probably the result of strong scattering. Furthermore, observations indicates that the strahl component is frequently and significantly anisotropic (Tper/Tpal approx.2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.

  15. Phylogenetic distribution of large-scale genome patchiness

    Directory of Open Access Journals (Sweden)

    Hackenberg Michael

    2008-04-01

    Full Text Available Abstract Background The phylogenetic distribution of large-scale genome structure (i.e. mosaic compositional patchiness has been explored mainly by analytical ultracentrifugation of bulk DNA. However, with the availability of large, good-quality chromosome sequences, and the recently developed computational methods to directly analyze patchiness on the genome sequence, an evolutionary comparative analysis can be carried out at the sequence level. Results The local variations in the scaling exponent of the Detrended Fluctuation Analysis are used here to analyze large-scale genome structure and directly uncover the characteristic scales present in genome sequences. Furthermore, through shuffling experiments of selected genome regions, computationally-identified, isochore-like regions were identified as the biological source for the uncovered large-scale genome structure. The phylogenetic distribution of short- and large-scale patchiness was determined in the best-sequenced genome assemblies from eleven eukaryotic genomes: mammals (Homo sapiens, Pan troglodytes, Mus musculus, Rattus norvegicus, and Canis familiaris, birds (Gallus gallus, fishes (Danio rerio, invertebrates (Drosophila melanogaster and Caenorhabditis elegans, plants (Arabidopsis thaliana and yeasts (Saccharomyces cerevisiae. We found large-scale patchiness of genome structure, associated with in silico determined, isochore-like regions, throughout this wide phylogenetic range. Conclusion Large-scale genome structure is detected by directly analyzing DNA sequences in a wide range of eukaryotic chromosome sequences, from human to yeast. In all these genomes, large-scale patchiness can be associated with the isochore-like regions, as directly detected in silico at the sequence level.

  16. Is the Japanese Distribution System Becoming More Accessible to Foreign Firms?

    OpenAIRE

    Ralf bebenroth; Nir Kshetri; Reinhard Hunerberg

    2009-01-01

    Complexities in the Japanese distribution system are well-publicized. An emerging body of literature has documented recent changes in the Japanese distribution system. In this paper, it is examined whether foreign firms' accessibility to the Japanese distribution system has changed in a favorable direction in recent years. Furthermore, as foreign firms vary widely in terms of institutional barriers and complexity they face in the Japanese market, the authors also investigate the determinants ...

  17. The Pore Structure of Direct Methanol Fuel Cell Electrodes

    DEFF Research Database (Denmark)

    Lund, Peter Brilner

    2005-01-01

    The pore structure and morphology of direct methanol fuel cell electrodes are characterized using mercury intrusion porosimetry and scanning electron microscopy. It is found that the pore size distributions of printed primer and catalyst layers are largely dictated by the powders used to make...

  18. ASSESSING ASTROPHYSICAL UNCERTAINTIES IN DIRECT DETECTION WITH GALAXY SIMULATIONS

    International Nuclear Information System (INIS)

    Sloane, Jonathan D.; Buckley, Matthew R.; Brooks, Alyson M.; Governato, Fabio

    2016-01-01

    We study the local dark matter velocity distribution in simulated Milky Way-mass galaxies, generated at high resolution with both dark matter and baryons. We find that the dark matter in the solar neighborhood is influenced appreciably by the inclusion of baryons, increasing the speed of dark matter particles compared to dark matter-only simulations. The gravitational potential due to the presence of a baryonic disk increases the amount of high velocity dark matter, resulting in velocity distributions that are more similar to the Maxwellian Standard Halo Model than predicted from dark matter-only simulations. Furthermore, the velocity structures present in baryonic simulations possess a greater diversity than expected from dark matter-only simulations. We show that the impact on the direct detection experiments LUX, DAMA/Libra, and CoGeNT using our simulated velocity distributions, and explore how resolution and halo mass within the Milky Way’s estimated mass range impact the results. A Maxwellian fit to the velocity distribution tends to overpredict the amount of dark matter in the high velocity tail, even with baryons, and thus leads to overly optimistic direct detection bounds on models that are dependent on this region of phase space for an experimental signal. Our work further demonstrates that it is critical to transform simulated velocity distributions to the lab frame of reference, due to the fact that velocity structure in the solar neighborhood appears when baryons are included. There is more velocity structure present when baryons are included than in dark matter-only simulations. Even when baryons are included, the importance of the velocity structure is not as apparent in the Galactic frame of reference as in the Earth frame.

  19. ASSESSING ASTROPHYSICAL UNCERTAINTIES IN DIRECT DETECTION WITH GALAXY SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Sloane, Jonathan D.; Buckley, Matthew R.; Brooks, Alyson M. [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States); Governato, Fabio [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)

    2016-11-01

    We study the local dark matter velocity distribution in simulated Milky Way-mass galaxies, generated at high resolution with both dark matter and baryons. We find that the dark matter in the solar neighborhood is influenced appreciably by the inclusion of baryons, increasing the speed of dark matter particles compared to dark matter-only simulations. The gravitational potential due to the presence of a baryonic disk increases the amount of high velocity dark matter, resulting in velocity distributions that are more similar to the Maxwellian Standard Halo Model than predicted from dark matter-only simulations. Furthermore, the velocity structures present in baryonic simulations possess a greater diversity than expected from dark matter-only simulations. We show that the impact on the direct detection experiments LUX, DAMA/Libra, and CoGeNT using our simulated velocity distributions, and explore how resolution and halo mass within the Milky Way’s estimated mass range impact the results. A Maxwellian fit to the velocity distribution tends to overpredict the amount of dark matter in the high velocity tail, even with baryons, and thus leads to overly optimistic direct detection bounds on models that are dependent on this region of phase space for an experimental signal. Our work further demonstrates that it is critical to transform simulated velocity distributions to the lab frame of reference, due to the fact that velocity structure in the solar neighborhood appears when baryons are included. There is more velocity structure present when baryons are included than in dark matter-only simulations. Even when baryons are included, the importance of the velocity structure is not as apparent in the Galactic frame of reference as in the Earth frame.

  20. Policy statement on gas distribution in Nova Scotia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-30

    This paper presented Nova Scotia's policy related to gas distribution. The government of Nova Scotia views natural gas as an economic enabler and is committed to ensuring that natural gas is available and accessible to Nova Scotians where it is economically feasible. Natural gas will give the province an efficient and clean burning energy supply that will make existing businesses more competitive. The province will support and facilitate the construction and operation of a gas distribution system by the private sector and will ensure that there is regulatory oversight by the Nova Scotia Utility and Review Board to protect the public interest. The government will also develop a plan for early conversion of government buildings to natural gas. This paper described the province's policy on gas distribution in relation to: (1) a province-wide franchise, (2) a supplemental franchise, (3) cost of service/performance based rates, (4) postage stamp rates, (5) a Maritimes and Northeast lateral policy, (6) direct access/bypass, (7) existing direct access user, (8) bundling of gas sales and other products and services, (9) licensing of gas marketers, (10) benefits, (11), regulatory efficiency, (12) municipal taxes, and (13) municipal operating agreements.

  1. Current distribution evaluation of dye-sensitized solar cell using HTS-SQUID-based magnetic measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Kenji, E-mail: Sakai-k@okayama-u.ac.jp; Tanaka, Kohei; Kiwa, Toshihiko; Tsukada, Keiji

    2016-11-15

    Highlights: • Current distribution and direction of dye-sensitized solar cell (DSSC) was measured. • Electrical current flowing in the indium tin oxide (ITO) glass substrate was uniform. • The distribution of electrical current depended on I–V characteristic. • Current direction changed when the performance of DSSC is low. - Abstract: The current flowing inside a dye-sensitized solar cell (DSSC) was measured using a high-temperature superconductor superconducting quantum interference device (HTS-SQUID)-based magnetic measurement system. Further, a new evaluation method of the DSSC, which is difficult to measure using the conventional method, was investigated to improve the characteristics of the DSSC. The tangential components of the magnetic field generated from the DSSC were measured using two HTS-SQUIDs, and the intensity and direction related to the electrical current were obtained by the measured magnetic field. The DSSCs prepared with different dyes and catalytic substances showed different current-intensity mapping. The current direction was different for the DSSC with low performance. In addition, the current flowing in the ITO layer of the ITO glass substrate was also measured and the results confirmed that it had uniform distribution. These results show that the current mapping and the direction of the electrical current depend on the internal factors of the DSSC, and the detection of the magnetic field distribution generated from it is expected to lead to its new evaluation method.

  2. Notes on representing grain size distributions obtained by electron backscatter diffraction

    International Nuclear Information System (INIS)

    Toth, Laszlo S.; Biswas, Somjeet; Gu, Chengfan; Beausir, Benoit

    2013-01-01

    Grain size distributions measured by electron backscatter diffraction are commonly represented by histograms using either number or area fraction definitions. It is shown here that they should be presented in forms of density distribution functions for direct quantitative comparisons between different measurements. Here we make an interpretation of the frequently seen parabolic tales of the area distributions of bimodal grain structures and a transformation formula between the two distributions are given in this paper. - Highlights: • Grain size distributions are represented by density functions. • The parabolic tales corresponds to equal number of grains in a bin of the histogram. • A simple transformation formula is given to number and area weighed distributions. • The particularities of uniform and lognormal distributions are examined

  3. Critical review of directional neutron survey meters

    International Nuclear Information System (INIS)

    Balmer, Matthew J.I.; Gamage, Kelum A.A.; Taylor, Graeme C.

    2014-01-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument. -- Highlights: • We critically review the existing literature into directional survey meters. • Instruments which could be adapted for this purpose are also reviewed. • Investigate the potential of much lighter portable real-time instrument. • Improvements to existing instruments are suggested to improve their design. • Boron-Doped liquid scintillator design is the most promising, but needs further work

  4. Stress Distribution in Graded Cellular Materials Under Dynamic Compression

    Directory of Open Access Journals (Sweden)

    Peng Wang

    Full Text Available Abstract Dynamic compression behaviors of density-homogeneous and density-graded irregular honeycombs are investigated using cell-based finite element models under a constant-velocity impact scenario. A method based on the cross-sectional engineering stress is developed to obtain the one-dimensional stress distribution along the loading direction in a cellular specimen. The cross-sectional engineering stress is contributed by two parts: the node-transitive stress and the contact-induced stress, which are caused by the nodal force and the contact of cell walls, respectively. It is found that the contact-induced stress is dominant for the significantly enhanced stress behind the shock front. The stress enhancement and the compaction wave propagation can be observed through the stress distributions in honeycombs under high-velocity compression. The single and double compaction wave modes are observed directly from the stress distributions. Theoretical analysis of the compaction wave propagation in the density-graded honeycombs based on the R-PH (rigid-plastic hardening idealization is carried out and verified by the numerical simulations. It is found that stress distribution in cellular materials and the compaction wave propagation characteristics under dynamic compression can be approximately predicted by the R-PH shock model.

  5. Assessment of energy supply and continuity of service in distribution network with renewable distributed generation

    International Nuclear Information System (INIS)

    Abdullah, M.A.; Agalgaonkar, A.P.; Muttaqi, K.M.

    2014-01-01

    Highlights: • Difficulties in assessing distribution network adequacy with DG are addressed. • Indices are proposed to assess adequacy of energy supply and service continuity. • Analytical methodology is developed to assess the proposed indices. • Concept of joint probability distribution of demand and generation is applied. - Abstract: Continuity of electricity supply with renewable distributed generation (DG) is a topical issue for distribution system planning and operation, especially due to the stochastic nature of power generation and time varying load demand. The conventional adequacy and reliability analysis methods related to bulk generation systems cannot be applied directly for the evaluation of adequacy criteria such as ‘energy supply’ and ‘continuity of service’ for distribution networks embedded with renewable DG. In this paper, new indices highlighting ‘available supply capacity’ and ‘continuity of service’ are proposed for ‘energy supply’ and ‘continuation of service’ evaluation of generation-rich distribution networks, and analytical techniques are developed for their quantification. A probability based analytical method has been developed using the joint probability of the demand and generation, and probability distributions of the proposed indices have been used to evaluate the network adequacy in energy supply and service continuation. A data clustering technique has been used to evaluate the joint probability between coincidental demand and renewable generation. Time sequential Monte Carlo simulation has been used to compare the results obtained using the proposed analytical method. A standard distribution network derived from Roy Billinton test system and a practical radial distribution network have been used to test the proposed method and demonstrate the estimation of the well-being of a system for hosting renewable DG units. It is found that renewable DG systems improve the ‘energy supply’ and

  6. Supply-demand balance in outward-directed networks and Kleiber's law.

    Science.gov (United States)

    Painter, Page R

    2005-11-10

    Recent theories have attempted to derive the value of the exponent alpha in the allometric formula for scaling of basal metabolic rate from the properties of distribution network models for arteries and capillaries. It has recently been stated that a basic theorem relating the sum of nutrient currents to the specific nutrient uptake rate, together with a relationship claimed to be required in order to match nutrient supply to nutrient demand in 3-dimensional outward-directed networks, leads to Kleiber's law (b = 3/4). The validity of the supply-demand matching principle and the assumptions required to prove the basic theorem are assessed. The supply-demand principle is evaluated by examining the supply term and the demand term in outward-directed lattice models of nutrient and water distribution systems and by applying the principle to fractal-like models of mammalian arterial systems. Application of the supply-demand principle to bifurcating fractal-like networks that are outward-directed does not predict 3/4-power scaling, and evaluation of water distribution system models shows that the matching principle does not match supply to demand in such systems. Furthermore, proof of the basic theorem is shown to require that the covariance of nutrient uptake and current path length is 0, an assumption unlikely to be true in mammalian arterial systems. The supply-demand matching principle does not lead to a satisfactory explanation for the approximately 3/4-power scaling of mammalian basal metabolic rate.

  7. Superthermal electron distribution measurements from polarized electron cyclotron emission

    International Nuclear Information System (INIS)

    Luce, T.C.; Efthimion, P.C.; Fisch, N.J.

    1988-06-01

    Measurements of the superthermal electron distribution can be made by observing the polarized electron cyclotron emission. The emission is viewed along a constant magnetic field surface. This simplifies the resonance condition and gives a direct correlation between emission frequency and kinetic energy of the emitting electron. A transformation technique is formulated which determines the anisotropy of the distribution and number density of superthermals at each energy measured. The steady-state distribution during lower hybrid current drive and examples of the superthermal dynamics as the runaway conditions is varied are presented for discharges in the PLT tokamak. 15 refs., 8 figs

  8. Direct aperture optimization for IMRT using Monte Carlo generated beamlets

    International Nuclear Information System (INIS)

    Bergman, Alanah M.; Bush, Karl; Milette, Marie-Pierre; Popescu, I. Antoniu; Otto, Karl; Duzenli, Cheryl

    2006-01-01

    This work introduces an EGSnrc-based Monte Carlo (MC) beamlet does distribution matrix into a direct aperture optimization (DAO) algorithm for IMRT inverse planning. The technique is referred to as Monte Carlo-direct aperture optimization (MC-DAO). The goal is to assess if the combination of accurate Monte Carlo tissue inhomogeneity modeling and DAO inverse planning will improve the dose accuracy and treatment efficiency for treatment planning. Several authors have shown that the presence of small fields and/or inhomogeneous materials in IMRT treatment fields can cause dose calculation errors for algorithms that are unable to accurately model electronic disequilibrium. This issue may also affect the IMRT optimization process because the dose calculation algorithm may not properly model difficult geometries such as targets close to low-density regions (lung, air etc.). A clinical linear accelerator head is simulated using BEAMnrc (NRC, Canada). A novel in-house algorithm subdivides the resulting phase space into 2.5x5.0 mm 2 beamlets. Each beamlet is projected onto a patient-specific phantom. The beamlet dose contribution to each voxel in a structure-of-interest is calculated using DOSXYZnrc. The multileaf collimator (MLC) leaf positions are linked to the location of the beamlet does distributions. The MLC shapes are optimized using direct aperture optimization (DAO). A final Monte Carlo calculation with MLC modeling is used to compute the final dose distribution. Monte Carlo simulation can generate accurate beamlet dose distributions for traditionally difficult-to-calculate geometries, particularly for small fields crossing regions of tissue inhomogeneity. The introduction of DAO results in an additional improvement by increasing the treatment delivery efficiency. For the examples presented in this paper the reduction in the total number of monitor units to deliver is ∼33% compared to fluence-based optimization methods

  9. The Impact of TCSC on IDMT Relays in SLG Fault in Distribution Networks

    Directory of Open Access Journals (Sweden)

    Lazhar Bougouffa

    2016-03-01

    Full Text Available IDMT Directional Over-Current Relays protection is one of the basic protective relaying for distribution systems, for fault detection and clearing as soon as possible. Its function would generally be changed in presence of FACTS devices. In this paper a study to investigate the direct effect of varying reactance of the TCSC on single-line-to-ground (SLG fault in compensated distribution systems. This paper, therefore presents the calculation of fault component, and directional over-current relay operating time characteristics for phase-to-earth fault involving the TCSC. The case study is compared between compensated and uncompensated system. The coordination of the relays is a nonlinear programming problem and it is solved by using MATLAB software.

  10. 78 FR 9796 - Airworthiness Directives; Cessna Aircraft Company Airplanes

    Science.gov (United States)

    2013-02-12

    ... (2) Model 172S, S/N l72S11074 through 172S11193. (d) Subject Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 2820, Aircraft Fuel Distribution System. (e) Unsafe... Airworthiness Directives; Cessna Aircraft Company Airplanes AGENCY: Federal Aviation Administration (FAA), DOT...

  11. Initial investigations of dose distribution patterns for an industrial electron accelerator

    International Nuclear Information System (INIS)

    Ehlermann, D.A.E.

    1994-01-01

    A newly developed accelerator for electrons in the dose range of up 10 mev at 10 kw performance replaces a similar type of accelerator that has been in use during the past 25 years. It is characterized by some decisive technical changes. The ray, rather than moving from one point to the next, is now distributed over the merchandise for the duration of an impulse. In the direction of conveyance, irradiation is carried out on successive fields as was done formerly. As the duration of impulse is no longer than 12 μs, some problems arose in respect of operation and measuring techniques: the time distribution of microwave energy or rays emitted during the individual impulses has a bearing on the dose distribution pattern at a right angle to the direction of transport in both the superficial and deep layers of the merchandise. Some of the initial measuring results are represented here. The accelerator's operational parameters were then so adjusted that a largely homogeneous dose distribution was achieved throughout. (orig.) [de

  12. Deterministic Secure Direct Communication Using Mixed state

    OpenAIRE

    Cai, Qing-yu

    2003-01-01

    We show an improved ping-pong protocol which is based on the protocol showed by Kim Bostrom and Timo Felbinger [Phys. Rev. Lett. 89, 187902 (2002); quant-ph/0209040]. We show that our protocol is asymptotically secure key distribution and quasisecure direct communication using a single photon resource. And this protocol can be can be carried out with great efficiency and speed using today's technology.

  13. Line and Circle Formation of Distributed Physical Mobile Robots

    OpenAIRE

    Yun, Xiaoping; Alptekin, Gokhan; Albayrak, Okay

    1997-01-01

    The formation problem of distributed mobile robots was studied in the literature for idealized robots. Idealized robots are able to instantaneously move in any directions, and are equipped with perfect range sensors. In this study, we address the formation problem of distributed mobile robots that are subject to physical constraints. Mobile robots considered in this study have physical dimensions and their motions are governed by physical laws. They are equipped with sonar and ...

  14. Halo-independent direct detection of momentum-dependent dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, John F. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Frandsen, Mads T.; Shoemaker, Ian M., E-mail: jcherry@lanl.gov, E-mail: frandsen@cp3-origins.net, E-mail: shoemaker@cp3-origins.net [CP3-Origins and the Danish Institute for Advanced Study, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2014-10-01

    We show that the momentum dependence of dark matter interactions with nuclei can be probed in direct detection experiments without knowledge of the dark matter velocity distribution. This is one of the few properties of DM microphysics that can be determined with direct detection alone, given a signal of dark matter in multiple direct detection experiments with different targets. Long-range interactions arising from the exchange of a light mediator are one example of momentum-dependent DM. For data produced from the exchange of a massless mediator we find for example that the mediator mass can be constrained to be ∼< 10 MeV for DM in the 20-1000 GeV range in a halo-independent manner.

  15. Halo-independent direct detection of momentum-dependent dark matter

    International Nuclear Information System (INIS)

    Cherry, John F.; Frandsen, Mads T.; Shoemaker, Ian M.

    2014-01-01

    We show that the momentum dependence of dark matter interactions with nuclei can be probed in direct detection experiments without knowledge of the dark matter velocity distribution. This is one of the few properties of DM microphysics that can be determined with direct detection alone, given a signal of dark matter in multiple direct detection experiments with different targets. Long-range interactions arising from the exchange of a light mediator are one example of momentum-dependent DM. For data produced from the exchange of a massless mediator we find for example that the mediator mass can be constrained to be ∼< 10 MeV for DM in the 20-1000 GeV range in a halo-independent manner

  16. Consensus problem in directed networks of multi-agents via nonlinear protocols

    International Nuclear Information System (INIS)

    Liu Xiwei; Chen Tianping; Lu Wenlian

    2009-01-01

    In this Letter, the consensus problem via distributed nonlinear protocols for directed networks is investigated. Its dynamical behaviors are described by ordinary differential equations (ODEs). Based on graph theory, matrix theory and the Lyapunov direct method, some sufficient conditions of nonlinear protocols guaranteeing asymptotical or exponential consensus are presented and rigorously proved. The main contribution of this work is that for nonlinearly coupled networks, we generalize the results for undirected networks to directed networks. Consensus under pinning control technique is also developed here. Simulations are also given to show the validity of the theories.

  17. Raytracing and Direct-Drive Targets

    Science.gov (United States)

    Schmitt, Andrew J.; Bates, Jason; Fyfe, David; Eimerl, David

    2013-10-01

    Accurate simulation of the effects of laser imprinting and drive asymmetries in directly driven targets requires the ability to distinguish between raytrace noise and the intensity structure produced by the spatial and temporal incoherence of optical smoothing. We have developed and implemented a smoother raytrace algorithm for our mpi-parallel radiation hydrodynamics code, FAST3D. The underlying approach is to connect the rays into either sheets (in 2D) or volume-enclosing chunks (in 3D) so that the absorbed energy distribution continuously covers the propagation area illuminated by the laser. We will describe the status and show the different scalings encountered in 2D and 3D problems as the computational size, parallelization strategy, and number of rays is varied. Finally, we show results using the method in current NIKE experimental target simulations and in proposed symmetric and polar direct-drive target designs. Supported by US DoE/NNSA.

  18. Angular distribution of the bremsstrahlung emission during lower-hybrid current drive on PLT

    International Nuclear Information System (INIS)

    von Goeler, S.; Stevens, J.; Bernabei, S.

    1985-06-01

    The bremsstrahlung emission from the PLT tokamak during lower-hybrid current drive has been measured as a function of angle between the magnetic field and the emission direction. The emission is peaked strongly in the forward direction, indicating a strong anisotropy of the electron-velocity distribution. The data demonstrate the existence of a nearly flat tail of the velocity distribution, which extends out to approximately 500 keV and which is interpreted as the plateau created by Landau damping of the lower-hybrid waves

  19. Determination of power density distribution of fuel assemblies for research reactor by directly measuring the strontium-91 activities

    International Nuclear Information System (INIS)

    Yuan, Liq-Ji

    1987-01-01

    This work described the investigations of reactor core power peaking and three dimensional power density distribution of present core configuration of Tsing Hua Open-pool reactor (THOR). An experimental program, based on non-destructive fuel gamma scanning of 91 Sr activities, provides the data of fission density distribution for individual fuel pin of four-rod TRIGA-LEU cluster or for MTR-type fuel assembly. The informations are essentially important for the safety of reactor operation and for fuel management especially for the mixed loading with three different types of fuel at present. The relative power peaking values and the power density distribution for present core are discussed. (author)

  20. Lubricant distribution determination by neutron radiography

    International Nuclear Information System (INIS)

    Stewart, P.A.E.

    1979-01-01

    Cold neutron radiation of energy less than 0.025 eV having a flux greater than 1 x 10 3 neutrons/square centimeter/second is used to diagnose temporal information about the spatial distribution of hydrocarbon fuel and lubrication oils in internal combustion engines, gas turbine engines and fuel systems. Images of the movement of fuel or oil are recorded by directing a beam of neutrons through an engine and using an image intensifier responsive to low light levels to intensify an image formed by neutrons which have been directed through the engine onto a fluorescent screen. The output image from the intensifier is recorded by a video or cine camera

  1. Automatic Management of Parallel and Distributed System Resources

    Science.gov (United States)

    Yan, Jerry; Ngai, Tin Fook; Lundstrom, Stephen F.

    1990-01-01

    Viewgraphs on automatic management of parallel and distributed system resources are presented. Topics covered include: parallel applications; intelligent management of multiprocessing systems; performance evaluation of parallel architecture; dynamic concurrent programs; compiler-directed system approach; lattice gaseous cellular automata; and sparse matrix Cholesky factorization.

  2. Distribution pattern of public transport passenger in Yogyakarta, Indonesia

    Science.gov (United States)

    Narendra, Alfa; Malkhamah, Siti; Sopha, Bertha Maya

    2018-03-01

    The arrival and departure distribution pattern of Trans Jogja bus passenger is one of the fundamental model for simulation. The purpose of this paper is to build models of passengers flows. This research used passengers data from January to May 2014. There is no policy that change the operation system affecting the nature of this pattern nowadays. The roads, buses, land uses, schedule, and people are relatively still the same. The data then categorized based on the direction, days, and location. Moreover, each category was fitted into some well-known discrete distributions. Those distributions are compared based on its AIC value and BIC. The chosen distribution model has the smallest AIC and BIC value and the negative binomial distribution found has the smallest AIC and BIC value. Probability mass function (PMF) plots of those models were compared to draw generic model from each categorical negative binomial distribution models. The value of accepted generic negative binomial distribution is 0.7064 and 1.4504 of mu. The minimum and maximum passenger vector value of distribution are is 0 and 41.

  3. Distributed 3-D iterative reconstruction for quantitative SPECT

    International Nuclear Information System (INIS)

    Ju, Z.W.; Frey, E.C.; Tsui, B.M.W.

    1995-01-01

    The authors describe a distributed three dimensional (3-D) iterative reconstruction library for quantitative single-photon emission computed tomography (SPECT). This library includes 3-D projector-backprojector pairs (PBPs) and distributed 3-D iterative reconstruction algorithms. The 3-D PBPs accurately and efficiently model various combinations of the image degrading factors including attenuation, detector response and scatter response. These PBPs were validated by comparing projection data computed using the projectors with that from direct Monte Carlo (MC) simulations. The distributed 3-D iterative algorithms spread the projection-backprojection operations for all the projection angles over a heterogeneous network of single or multi-processor computers to reduce the reconstruction time. Based on a master/slave paradigm, these distributed algorithms provide dynamic load balancing and fault tolerance. The distributed algorithms were verified by comparing images reconstructed using both the distributed and non-distributed algorithms. Computation times for distributed 3-D reconstructions running on up to 4 identical processors were reduced by a factor approximately 80--90% times the number of the processors participating, compared to those for non-distributed 3-D reconstructions running on a single processor. When combined with faster affordable computers, this library provides an efficient means for implementing accurate reconstruction and compensation methods to improve quality and quantitative accuracy in SPECT images

  4. A methodology to identify the intake charge cylinder-to-cylinder distribution in turbocharged direct injection Diesel engines

    Science.gov (United States)

    Luján, José M.; Galindo, José; Serrano, José R.; Pla, Benjamín

    2008-06-01

    Exhaust gas recirculation (EGR) is currently the most important NOx emission control system. During the last few years the EGR rate has increased progressively as pollutant emission regulations have become more restrictive. High EGR rate levels have given the effect of the unsuitable EGR and air distribution between cylinders away, which causes undesirable engine behavior. In this sense, the study of the EGR distribution between cylinders achieves high importance. However, despite the fact that the EGR is continuously under study, not many studies have been undertaken to approach its distribution between cylinders. In concordance with the aspects outlined before, the aim of this paper is to propose a methodology that permits us to identify the EGR cylinder-to-cylinder dispersion in a commercial engine. In order to achieve this objective, experimental tests have been combined with both one-dimensional and three-dimensional fluid dynamic models.

  5. Infants distinguish antisocial actions directed towards fair and unfair agents.

    Directory of Open Access Journals (Sweden)

    Marek Meristo

    Full Text Available Three experiments provide evidence of an incipient sense of fairness in preverbal infants. Ten-month-old infants were shown cartoon videos with two agents, the 'donors', who distributed resources to two identical recipients. One donor always distributed the goods equally, while the other performed unequal distributions by giving everything to one recipient. In the test phase, a third agent hit or took resources away from either the fair or the unfair donor. We found that infants looked longer when the antisocial actions were directed towards the unfair rather than the fair donor. These findings support the view that infants are able to evaluate agents based on their distributive actions and suggest that the foundations of human socio-moral competence are acquired independently of parental feedback and linguistic experience.

  6. Temperature and flow distribution in planar SOFC stacks

    Directory of Open Access Journals (Sweden)

    Monica Østenstad

    1995-07-01

    Full Text Available Simulation of a planar Solid Oxide Fuel Cell stack requires the solution of the mass balances of the chemical species, the energy balances, the charge balance and the channel flow equations in order to compute the species concentrations, the temperature distributions, the current density and the channel flows. The unit cell geometry can be taken into account by combining detailed modeling of a unit cell with a homogenized model of a whole stack. In this study the effect of the asymmetric temperature distribution on the channel flows in a conventional cross-flow design has been investigated. The bidirectional cross-flow design is introduced, for which we can show more directional temperature and flow distributions.

  7. Mathematical simulation of gamma-radiation angle distribution measurements

    International Nuclear Information System (INIS)

    Batij, V.G.; Batij, E.V.; Egorov, V.V.; Fedorchenko, D.V.; Kochnev, N.A.

    2008-01-01

    We developed mathematical model of the facility for gamma-radiation angle distribution measurement and calculated response functions for gamma-radiation intensities. We developed special software for experimental data processing, the 'Shelter' object radiation spectra unfolding and Sphere detector (ShD) angle resolution estimation. Neuronet method using for detection of the radiation directions is given. We developed software based on the neuronet algorithm, that allows obtaining reliable distribution of gamma-sources that make impact on the facility detectors at the measurement point. 10 refs.; 15 figs.; 4 tab

  8. Renewable resource policy when distributional impacts matter

    International Nuclear Information System (INIS)

    Horan, R.D.; Shortle, J.S.; Bulte, E.H.

    1999-01-01

    The standard assumption in bioeconomic resource models is that optimal policies maximize the present value of economic surplus to society. This assumption implies that regulatory agencies should not be concerned with the distributional consequences of management strategies. Both contemporary welfare-theoretic and rent-seeking approaches suggests distributional issues are important in designing resource management policies. This paper explores resource management when the managing agency has preferences defined over the economic welfare of various groups with a direct economic interest in the use of resources. Policy schemes consistent with this approach are derived and compared with standard results. 42 refs

  9. Experimental study on energy distribution of the hot electrons generated by femtosecond laser interacting with solid targets

    International Nuclear Information System (INIS)

    Gu Yuqiu; Zheng Zhijian; Zhou Weimin; Wen Tianshu; Chunyu Shutai; Cai Dafeng; Sichuan Univ., Chengdu; Neijiang Teachers College, Neijiang; Jiao Chunye; Chen Hao; Sichuan Univ., Chengdu; Yang Xiangdong

    2005-01-01

    This paper reports the results of the experiment of hot electron energy distribution during the femtosecond laser-solid target interaction. The hot electrons formed an anisotropic energy distribution. In the direction of the target normal, the energy spectrum of the hot electron was a Maxwellian-like distribution with an effective temperature of 206 keV, which was due to the resonance absorption. In the direction of the specular reflection of laser, there appeared a local plateau of hot electron energy spectrum at the beginning and then it was decreased gradually, which maybe produced by several acceleration mechanisms. The effective temperature and the yield of hot electrons in the direction of the target normal is larger than those in the direction of the specular reflection of laser, which proves that the resonance absorption mechanism is more effective than others. (authors)

  10. Body size distribution of the dinosaurs.

    Directory of Open Access Journals (Sweden)

    Eoin J O'Gorman

    Full Text Available The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.

  11. Body size distribution of the dinosaurs.

    Science.gov (United States)

    O'Gorman, Eoin J; Hone, David W E

    2012-01-01

    The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.

  12. Body Size Distribution of the Dinosaurs

    Science.gov (United States)

    O’Gorman, Eoin J.; Hone, David W. E.

    2012-01-01

    The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size. PMID:23284818

  13. Review on Water Distribution of Cooling Tower in Power Station

    Science.gov (United States)

    Huichao, Zhang; Lei, Fang; Hao, Guang; Ying, Niu

    2018-04-01

    As the energy sources situation is becoming more and more severe, the importance of energy conservation and emissions reduction gets clearer. Since the optimization of water distribution system of cooling tower in power station can save a great amount of energy, the research of water distribution system gets more attention nowadays. This paper summarizes the development process of counter-flow type natural draft wet cooling tower and the water distribution system, and introduces the related domestic and international research situation. Combining the current situation, we come to the conclusion about the advantages and disadvantages of the several major water distribution modes, and analyze the problems of the existing water distribution ways in engineering application, furthermore, we put forward the direction of water distribution mode development on the basis knowledge of water distribution of cooling tower. Due to the water system can hardly be optimized again when it’s built, choosing an appropriate water distribution mode according to actual condition seems to be more significant.

  14. An improved method for calculating force distributions in moment-stiff timber connections

    DEFF Research Database (Denmark)

    Ormarsson, Sigurdur; Blond, Mette

    2012-01-01

    An improved method for calculating force distributions in moment-stiff metal dowel-type timber connections is presented, a method based on use of three-dimensional finite element simulations of timber connections subjected to moment action. The study that was carried out aimed at determining how...... the slip modulus varies with the angle between the direction of the dowel forces and the fibres in question, as well as how the orthotropic stiffness behaviour of the wood material affects the direction and the size of the forces. It was assumed that the force distribution generated by the moment action...

  15. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-02

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

  16. Direct versus indirect detection of supersymmetric dark matter

    International Nuclear Information System (INIS)

    2003-01-01

    This document gathers the slides that were presented during the workshop 'direct versus indirect detection of supersymmetric dark matter'(about 30 contributions). This workshop intended to bring together people from the particle theory community, astrophysicists and cosmologists, as well as experimentalists involved in the detection of dark matter. The aim is to generate a discussion about current and future strategies for detection of SUSY dark matter (with focus, but not exclusively, on neutralinos). Complementarities between accelerator, direct and indirect searches as well as a comparison between the uncertainties in direct and indirect searches of dark matter, are supposed to be discussed. Among the issues which will be addressed are: -) the crucial questions related to the structure of galaxies (local dark matter density, clumping, anomalous velocity distributions, etc.) ; -) the possibilities offered by the present and future experimental facilities for direct and indirect (photon, neutrino) searches; -) the potential for the discovery of SUSY at LHC and beyond; and -) the parameterization of the SUSY breaking models beyond the minimal versions

  17. A fast direct sampling algorithm for equilateral closed polygons

    International Nuclear Information System (INIS)

    Cantarella, Jason; Duplantier, Bertrand; Shonkwiler, Clayton; Uehara, Erica

    2016-01-01

    Sampling equilateral closed polygons is of interest in the statistical study of ring polymers. Over the past 30 years, previous authors have proposed a variety of simple Markov chain algorithms (but have not been able to show that they converge to the correct probability distribution) and complicated direct samplers (which require extended-precision arithmetic to evaluate numerically unstable polynomials). We present a simple direct sampler which is fast and numerically stable, and analyze its runtime using a new formula for the volume of equilateral polygon space as a Dirichlet-type integral. (paper)

  18. Simulation of the measure of the microparticle size distribution in two dimensions

    International Nuclear Information System (INIS)

    Lameiras, F.S.; Pinheiro, P.

    1987-01-01

    Different size distributions of plane figures were generated in a computer as a simply connected network. These size distributions were measured by the Saltykov method for two dimensions. The comparison between the generated and measured distributions showed that the Saltkov method tends to measure larger scattering than the real one and to move the maximum of the real distribution to larger diameters. These erros were determined by means of the ratio of the perimeter of the figures per unit area directly measured and the perimeter calculated from the size distribution obtained by using the SaltyKov method. (Author) [pt

  19. A framework for distributed mixed-language scientific applications

    International Nuclear Information System (INIS)

    Quarrie, D.R.

    1996-01-01

    The Object Management Group has defined an architecture (COBRA) for distributed object applications based on an Object Broker and Interface Definition Language. This project builds upon this architecture to establish a framework for the creation of mixed language scientific applications. A prototype compiler has been written that generates FORTRAN 90 or Eiffel subs and skeletons and the required C++ glue code from an input IDL file that specifies object interfaces. This generated code can be used directly for non-distributed mixed language applications or in conjunction with the C++ code generated from a commercial IDL compiler for distributed applications. A feasibility study is presently to see whether a fully integrated software development environment for distributed, mixed-language applications can be created by modifying the back-end code generator of a commercial CASE tool to emit IDL. (author)

  20. Epistemic Protocols for Distributed Gossiping

    Directory of Open Access Journals (Sweden)

    Krzysztof R. Apt

    2016-06-01

    Full Text Available Gossip protocols aim at arriving, by means of point-to-point or group communications, at a situation in which all the agents know each other's secrets. We consider distributed gossip protocols which are expressed by means of epistemic logic. We provide an operational semantics of such protocols and set up an appropriate framework to argue about their correctness. Then we analyze specific protocols for complete graphs and for directed rings.

  1. Angular distributions of autoionization electrons from Ne(2p43s2) 1D in Li+-Ne collisions

    International Nuclear Information System (INIS)

    Oud, M.; Pas, S.F. te; Westerveld, W.B.; Niehaus, A.

    1993-01-01

    Angular distributions of autoionization electrons from Ne(2p 4 3s 2 ) 1 D due to Li + -Ne collisions measured in coincidence with the scattered projectile ions are presented. The measurements are performed at four different collision energies between 1.0 keV and 3.0 keV, and the complex population amplitudes for the excited 1 D state are determined. A nearly pure M = O sublevel population is found with respect to an axis coinciding with the direction of the angular distribution. The direction of the angular distribution is found to deviate from the final direction of the asymptotic internuclear axis. (author)

  2. On the genealogy of branching random walks and of directed polymers

    Science.gov (United States)

    Derrida, Bernard; Mottishaw, Peter

    2016-08-01

    It is well known that the mean-field theory of directed polymers in a random medium exhibits replica symmetry breaking with a distribution of overlaps which consists of two delta functions. Here we show that the leading finite-size correction to this distribution of overlaps has a universal character which can be computed explicitly. Our results can also be interpreted as genealogical properties of branching Brownian motion or of branching random walks.

  3. Experimental investigations on frictional resistance and velocity distribution of rough wall with regularly distributed triangular ribs

    International Nuclear Information System (INIS)

    Motozawa, Masaaki; Ito, Takahiro; Iwamoto, Kaoru; Kawashima, Hideki; Ando, Hirotomo; Senda, Tetsuya; Tsuji, Yoshiyuki; Kawaguchi, Yasuo

    2013-01-01

    Highlights: • Flow over the regularly distributed triangular ribs was investigated. • Simultaneous measurement of flow resistance and velocity profile was performed. • Flow resistance was measured directly and velocity profile was measured by LDV. • Flow resistance was estimated by the information of the velocity field. • Estimated flow resistance has good agreement with the measured flow resistance. -- Abstract: The relationship between the flow resistance of a turbulent flow over triangular ribs regularly distributed on a wall surface and the velocity distribution around the ribs was investigated experimentally. A concentric cylinder device composed of an inner test cylinder and an outer cylinder was employed to measure the flow resistance using the torque of the shaft of the inner cylinder and the velocity distribution of the flow around a rib by laser Doppler velocimetry (LDV) simultaneously. We prepared four inner test cylinders having 4, 8, 12 and 16 triangular ribs on the surface with the same interval between them. Each rib had an isosceles right triangle V-shape and a height of 2 mm. To investigate the relationship between flow resistance and velocity distribution, we estimated the frictional drag and pressure drag acting on the surface of the ribs separately using the velocity distribution. Therefore, we could also estimate the total flow resistance using the velocity distribution. As a result of the experiment, the flow resistance and the attachment point downstream of the rib were shown to depend on the distance between ribs. Moreover, the flow resistance estimated using the velocity distribution had good agreement with the flow resistance measured using the torque of the inner cylinder

  4. THE STRUCTURE AND TERRITORIAL DYNAMIC OF FOREIGN DIRECT INVESTMENT IN ROMANIA

    Directory of Open Access Journals (Sweden)

    LILIANA SCUTARU

    2015-03-01

    Full Text Available This paper analyzes the structure of foreign direct investment in Romania, FDI agglomeration areas at the local level and their fields, with a particular analysis on greenfield investments because this type of investment is, par excellence, the promoter of new technologies and technical and technological progress. In this respect, the paper considers the analysis of foreign direct investment stock in greenfield enterprises and their location and territorial distribution by regions in Romania of stock of greenfield investments. The research reveals that, in the period under review, greenfield investments in Romania have shifted from the manufacturing sector to the service sector, thereby increasing the country's vulnerability to financial risks and speculation worldwide. In terms of regional distribution, the research highlights the fact that FDI are highly unevenly localized in Romania

  5. Multi-objective analysis of impacts of distributed generation placement on the operational characteristics of networks for distribution system planning

    Energy Technology Data Exchange (ETDEWEB)

    Barin, Alexandre; Pozzatti, Luis F.; Canha, Luciane N.; Abaide, Alzenira R. [Federal University of Santa Maria - UFSM, Post-graduation Program of Electric Engineering - PPGEE, Center of Studies of Energy and Environment - CEEMA, Santa Maria, RS (Brazil); Machado, Ricardo Q. [University of Sao Paulo - USP, Sao Carlos, SP (Brazil); Arend, Gustavo [State Electric Energy Company - CEEE-D, Division of Distribution, Porto Alegre, RS (Brazil)

    2010-12-15

    Recent advances in energy technology generation and new directions in electricity regulation have made distributed generation (DG) more widespread, with consequent significant impacts on the operational characteristics of distribution networks. For this reason, new methods for identifying such impacts are needed, together with research and development of new tools and resources to maintain and facilitate continued expansion towards DG. This paper presents a study aimed at determining appropriate DG sites for distribution systems. The main considerations which determine DG sites are also presented, together with an account of the advantages gained from correct DG placement. The paper intends to define some quantitative and qualitative parameters evaluated by Digsilent registered, GARP3 registered and DSA-GD software. A multi-objective approach based on the Bellman-Zadeh algorithm and fuzzy logic is used to determine appropriate DG sites. The study also aims to find acceptable DG locations both for distribution system feeders, as well as for nodes inside a given feeder. (author)

  6. Electricity market design requirements for DC distribution systems

    NARCIS (Netherlands)

    Piao, L.; de Weerdt, M.M.; de Vries, L.J.

    2017-01-01

    DC distribution systems (DCDS) connect local generators and loads directly. By avoiding unnecessary losses in AC-DC conversion, DCDS offers higher energy efficiency. Since different parties in a DCDS may have conflicting goals, matching between power supply and demand should be done with carefully

  7. The effects of stabilizing and directional selection on phenotypic and genotypic variation in a population of RNA enzymes.

    Science.gov (United States)

    Hayden, Eric J; Bratulic, Sinisa; Koenig, Iwo; Ferrada, Evandro; Wagner, Andreas

    2014-02-01

    The distribution of variation in a quantitative trait and its underlying distribution of genotypic diversity can both be shaped by stabilizing and directional selection. Understanding either distribution is important, because it determines a population's response to natural selection. Unfortunately, existing theory makes conflicting predictions about how selection shapes these distributions, and very little pertinent experimental evidence exists. Here we study a simple genetic system, an evolving RNA enzyme (ribozyme) in which a combination of high throughput genotyping and measurement of a biochemical phenotype allow us to address this question. We show that directional selection, compared to stabilizing selection, increases the genotypic diversity of an evolving ribozyme population. In contrast, it leaves the variance in the phenotypic trait unchanged.

  8. The direct radiative effect of biomass burning aerosols over southern Africa

    Directory of Open Access Journals (Sweden)

    S. J. Abel

    2005-01-01

    Full Text Available A multi-column radiative transfer code is used to assess the direct radiative effect of biomass burning aerosols over the southern African region during September. The horizontal distribution of biomass smoke is estimated from two sources; i General Circulation Model (GCM simulations combined with measurements from the Aerosol Robotic Network (AERONET of Sun photometers; ii data from the Moderate resolution Imaging Spectrometer (MODIS satellite. Aircraft and satellite measurements are used to constrain the cloud fields, aerosol optical properties, vertical structure, and land surface albedo included in the model. The net regional direct effect of the biomass smoke is -3.1 to -3.6 Wm-2 at the top of atmosphere, and -14.4 to -17.0 Wm-2 at the surface for the MODIS and GCM distributions of aerosol. The direct radiative effect is shown to be highly sensitive to the prescribed vertical profiles and aerosol optical properties. The diurnal cycle of clouds and the spectral dependency of surface albedo are also shown to play an important role.

  9. Angular distributions and total yield of laser ablated silver

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Nordskov, A.; Schou, Jørgen

    1997-01-01

    The angular distribution of laser ablated silver has been measured in situ with a newly constructed setup with an array of microbalances. The distribution is strongly peaked in the forward direction corresponding to cospθ, where p varies between 5 and 9 for laser fluences from 2 to 7 J/cm2 at 355...... nm for a beam spot of 0.015 cm2. The total deposited yield is of the order 1015 Ag-atoms per pulse....

  10. Using Johnson Distribution for Automatic Threshold Setting in Wind Turbine Condition Monitoring System

    DEFF Research Database (Denmark)

    Marhadi, Kun Saptohartyadi; Skrimpas, Georgios Alexandros

    2014-01-01

    not rep- resent the whole operating conditions of a turbine, which re- sults in uncertainty in the parameters of the fitted probabil- ity distribution and the thresholds calculated. In this study Johnson distribution is used to identify shape, location, and scale parameters of distribution that can best...... fit vibration data. This study shows that using Johnson distribution can elim- inate testing or fitting various distributions to the data, and have more direct approach to obtain optimal thresholds. To quantify uncertainty in the thresholds due to limited data, im- plementations with bootstrap method...

  11. Distributed Anemometry via High-Definition Fiber Optic Sensing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna is developing a distributed anemometer that can directly measure flow field velocity profiles using high-definition fiber optic sensing (HD-FOS). The concept is...

  12. Use of direct marketing in nonprofit organizations

    Directory of Open Access Journals (Sweden)

    Popović Ana

    2010-01-01

    Full Text Available Non profit organizations represent very heterogenus group of organizations which can be determined by the fact that they are being used as forums for creation and distribution of new ideas. Their aim is to raise public awareness on the purpose they promote and get the reply for their initiatives for gaining support in form of monetary sources for charities, vote for political candidate or achieving a communicational goal. Non governmental organizations, as the dominant form of non profit organizations, are being founded with mission to raise public awareness on some issue or provide help to certain marginalized group. The direct marketing instruments and techniques are considered to be very useful for achieving mission formulated that way. They are, by their nature, precisely targeted and objective-oriented and require direct reply. Apart from that, direct marketing activities are cost-efficient, costs that they generate can be shown in financial reports, and results of undertaken initiatives are directly measurable. All the mentioned lead to conclusion that direct marketing is, for additional reasons, even more appropriate for NPOs having in mind that they usually have limited available resources. In the relevant literature two main roles of direct marketing in non profit organizations are mentioned - managing relations with representatives of stakeholder groups and fundraising. In this paper, therefore, after the facts referring functioning of NPOs, direct marketing strategies used for mentioned purposes will be presented consequently.

  13. 1997 survey of residential direct sales of natural gas in Canada

    International Nuclear Information System (INIS)

    Bacalso, N.; Given, G.

    1997-01-01

    This report comments on the prevailing state of direct sales of natural gas in Canada and shows how the situation has changed since the Canadian Energy Research Institute initiated its first survey in 1994. The report describes current regulations relating to direct sales and quantifies direct sales activity in each of the provinces. Information on direct sales volumes and the number of direct sales customers contained in the report was gathered through interviews with local distribution companies, provincial regulatory commissions and many natural gas brokers and marketers. It was noted that Ontario and Quebec (where the industry is self-regulating) were the two provinces with the highest volumes of residential direct sales. The need for regular monitoring was recommended in view of the current climate of rapid changes in the energy market. 7 tabs., 1 fig

  14. Supply-demand balance in outward-directed networks and Kleiber's law

    Directory of Open Access Journals (Sweden)

    Painter Page R

    2005-11-01

    Full Text Available Abstract Background Recent theories have attempted to derive the value of the exponent α in the allometric formula for scaling of basal metabolic rate from the properties of distribution network models for arteries and capillaries. It has recently been stated that a basic theorem relating the sum of nutrient currents to the specific nutrient uptake rate, together with a relationship claimed to be required in order to match nutrient supply to nutrient demand in 3-dimensional outward-directed networks, leads to Kleiber's law (b = 3/4. Methods The validity of the supply-demand matching principle and the assumptions required to prove the basic theorem are assessed. The supply-demand principle is evaluated by examining the supply term and the demand term in outward-directed lattice models of nutrient and water distribution systems and by applying the principle to fractal-like models of mammalian arterial systems. Results Application of the supply-demand principle to bifurcating fractal-like networks that are outward-directed does not predict 3/4-power scaling, and evaluation of water distribution system models shows that the matching principle does not match supply to demand in such systems. Furthermore, proof of the basic theorem is shown to require that the covariance of nutrient uptake and current path length is 0, an assumption unlikely to be true in mammalian arterial systems. Conclusion The supply-demand matching principle does not lead to a satisfactory explanation for the approximately 3/4-power scaling of mammalian basal metabolic rate.

  15. The three-dimensional distribution of minerals in potato tubers

    Science.gov (United States)

    Subramanian, Nithya K.; White, Philip J.; Broadley, Martin R.; Ramsay, Gavin

    2011-01-01

    Background and Aims The three-dimensional distributions of mineral elements in potato tubers provide insight into their mechanisms of transport and deposition. Many of these minerals are essential to a healthy human diet, and characterizing their distribution within the potato tuber will guide the effective utilization of this staple foodstuff. Methods The variation in mineral composition within the tuber was determined in three dimensions, after determining the orientation of the harvested tuber in the soil. The freeze-dried tuber samples were analysed for minerals using inductively coupled plasma-mass spectrometry (ICP-MS). Minerals measured included those of nutritional significance to the plant and to human consumers, such as iron, zinc, copper, calcium, magnesium, manganese, phosphorus, potassium and sulphur. Key Results The concentrations of most minerals were higher in the skin than in the flesh of tubers. The potato skin contained about 17 % of total tuber zinc, 34 % of calcium and 55 % of iron. On a fresh weight basis, most minerals were higher in tuber flesh at the stem end than the bud end of the tuber. Potassium, however, displayed a gradient in the opposite direction. The concentrations of phosphorus, copper and calcium decreased from the periphery towards the centre of the tuber. Conclusions The distribution of minerals varies greatly within the potato tuber. Low concentrations of some minerals relative to those in leaves may be due to their low mobility in phloem, whereas high concentrations in the skin may reflect direct uptake from the soil across the periderm. In tuber flesh, different minerals show distinct patterns of distribution in the tuber, several being consistent with phloem unloading in the tuber and limited onward movement. These findings have implications both for understanding directed transport of minerals in plants to stem-derived storage organs and for the dietary implications of different food preparation methods for potato tubers

  16. Nuclear momentum distribution and relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    In terms of a direct fragmentation process and a hard-scattering process, the proton-inclusive data for the reaction α + 12 C → p + X have been successfully analyzed. The extracted semiempirical momentum distribution indicates possible evidence of nuclear correlations and final-state interactions. 4 figures

  17. Estimating hourly direct and diffuse solar radiation for the compilation of solar radiation distribution maps

    International Nuclear Information System (INIS)

    Ueyama, H.

    2005-01-01

    This paper presents a new method for estimating hourly direct and diffuse solar radiation. The essence of the method is the estimation of two important factors related to solar radiation, atmospheric transmittance and a dimensionless parameter, using empirical and physical equations and data from general meteorological observation stations. An equation for atmospheric transmittance of direct solar radiation and a dimensionless parameter representing diffuse solar radiation are developed. The equation is based on multiple regression analysis and uses three parameters as explanatory variates: calculated hourly extraterrestrial solar radiation on a horizontal plane, observed hourly sunshine duration and hourly precipitation as observed at a local meteorological observatory. The dimensionless parameter for estimating a diffuse solar radiation is then determined by linear least squares using observed hourly solar radiation at a local meteorological observatory. The estimated root mean square error (RMSE) of hourly direct and diffuse solar radiation is about 0.0-0.2 MJ¥m(-2)¥h(-1) in each mean period. The RMSE of the ten-day and monthly means of these quantities is about 0.0-0.2 MJ¥m(-2)¥h(-1), based on comparisons with AMeDAS station data, located at a distance of 6 km

  18. Characterisation of dispersion mechanisms in an urban catchment using a deterministic spatially distributed direct hydrograph travel time model

    Science.gov (United States)

    Rossel, F.; Gironas, J. A.

    2012-12-01

    The link between stream network structure and hydrologic response for natural basins has been extensively studied. It is well known that stream network organization and flow dynamics in the reaches combine to shape the hydrologic response of natural basins. Geomorphologic dispersion and hydrodynamic dispersion along with hillslope processes control to a large extent the overall variance of the hydrograph, particularly under the assumption of constant celerity throughout the basin. In addition, a third mechanism referred as to kinematic dispersion becomes relevant when considering spatial variations of celerity. On contrary, the link between the drainage network structure and overall urban terrain, and the hydrologic response in urban catchments has been much less studied. In particular, the characterization of the different dispersion mechanisms within urban areas remains to be better understood. In such areas artificial elements are expected to contribute to the total dispersion due to the variety of geometries and the spatial distribution of imperviousness. This work quantifies the different dispersion mechanisms in an urban catchment, focusing on their relevance and the spatial scales involved. For this purpose we use the Urban Morpho-climatic Instantaneous Unit Hydrograph model, a deterministic spatially distributed direct hydrograph travel time model, which computes travel times in hillslope, pipe, street and channel cells using formulations derived from kinematic wave theory. The model was applied to the Aubeniere catchment, located in Nantes, France. Unlike stochastic models, this deterministic model allows the quantification of dispersion mechanism at the local scale (i.e. the grid-cell). We found that kinematic dispersion is more relevant for small storm events, whereas geomorphologic dispersion becomes more significant for larger storms, as the mean celerity within the catchment increases. In addition, the total dispersion relates to the drainage area in

  19. Dependence of the wind climate of Ireland on the direction distribution of geostrophic wind; Die Abhaengigkeit des Windklimas von Irland von der Richtungsverteilung des geostrophischen Windes

    Energy Technology Data Exchange (ETDEWEB)

    Frank, H.P. [Forskningcenter Risoe, Roskilde (Denmark). Afdelingen for Vindenergi og Atmosfaerefysik

    1998-01-01

    The wind climate of Ireland is calculated using the Karlsruhe Atmospheric Mesoscale Model KAMM. The dependence of the simulated wind energy on the direction distribution of geostrophic wind is studied. As geostrophic winds from the south-west are most frequent, sites on the north-west coast are particularly suited for wind power stations. In addition, geostrophic wind increases from the south-east to the north-west. (orig.) [Deutsch] Das Windklima von Irland wurde mit dem Karlsruher Atmosphaerischen Mesoskaligen Modell KAMM berechnet. Hier wird die Abhaengigkeit der simultierten Windenergie von der Richtungsverteilung des geostrophischen Windes untersucht. Da geostrophische Winde aus Suedwest am haeufigsten vorkommen, eignet sich besonders die Nordwestkueste als Standort fuer Windkraftanlagen. Zusaetzlich nimmt auch der mittlere geostrophische Wind von Suedost nach Nordwest zu. (orig.)

  20. Trends of distributed generation development in Lithuania

    International Nuclear Information System (INIS)

    Miskinis, Vaclovas; Norvaisa, Egidijus; Galinis, Arvydas; Konstantinaviciute, Inga

    2011-01-01

    The closure of Ignalina Nuclear Power Plant, impact of recent global recession of the economy, as well as changes and problems posed by the global climate change require significant alterations in the Lithuanian energy sector development. This paper describes the current status and specific features of the Lithuanian power system, and in particular discusses the role of the distributed generators. Country's energy policy during last two decades was focused on substantial modernisation of the energy systems, their reorganisation and creation of appropriate institutional structure and necessary legal basis. The most important factors stimulating development of distributed generation in Lithuania are the following: international obligations to increase contribution of power plants using renewable energy sources into electricity production balance; development of small (with capacity less than 50 MW) cogeneration power plants; implementation of energy policy directed to promotion of renewable energy sources and cogeneration. Analysis of the legal and economic environment, as well as principles of regulation of distributed generation and barriers to its development is presented. - Highlights: → Paper describes current status and specific features of the Lithuanian power system. → Analysis of the legal and economic environment regarding distributed generation. → Current situation is not favourable for distributed generation development. → Problems, barriers, principles of regulation of distributed generation is presented. → New energy policy regarding distributed generation and renewables.

  1. A method to measure the suprathermal density distribution by electron cyclotron emission

    International Nuclear Information System (INIS)

    Tutter, M.

    1986-05-01

    Electron cyclotron emission spectra of suprathermal electrons in a thermal main plasma are calculated. It is shown that for direction of observation oblique to the magnetic field, which decays in direction to the receiver, one may obtain information on the spatial density distribution of the suprathermal electrons from those spectra. (orig.)

  2. A comparison of decentralized, distributed, and centralized vibro-acoustic control.

    Science.gov (United States)

    Frampton, Kenneth D; Baumann, Oliver N; Gardonio, Paolo

    2010-11-01

    Direct velocity feedback control of structures is well known to increase structural damping and thus reduce vibration. In multi-channel systems the way in which the velocity signals are used to inform the actuators ranges from decentralized control, through distributed or clustered control to fully centralized control. The objective of distributed controllers is to exploit the anticipated performance advantage of the centralized control while maintaining the scalability, ease of implementation, and robustness of decentralized control. However, and in seeming contradiction, some investigations have concluded that decentralized control performs as well as distributed and centralized control, while other results have indicated that distributed control has significant performance advantages over decentralized control. The purpose of this work is to explain this seeming contradiction in results, to explore the effectiveness of decentralized, distributed, and centralized vibro-acoustic control, and to expand the concept of distributed control to include the distribution of the optimization process and the cost function employed.

  3. Spatial distribution measured by the modulation transfer function

    International Nuclear Information System (INIS)

    Rossi, P.; Brice, D.K.; Doyle, B.L.

    2003-01-01

    Spatial distributions in ion micro-beam and IBA experimental practice are regularly characterized through the parameters of FWHM and tail area percentage (TF, tail fraction). Linear and stationary transducer theory allows these distributions to be described in the Fourier-dual frequency space, and provides an indirect method to evaluate them through measurement of the modulation transfer function (MTF). We suggest direct measurement of MTF by employing bar pattern grids, similar to those used for calibration of radiological equipment. Assuming spatial distributions of the form exp(-(|αx|) η ), we are able to relate the MTF measurements to the more popular FWHM and TF. This new approach to determine spatial resolution can become a standard for use by the micro-beam community

  4. Comprehensive evaluation index system of total supply capability in distribution network

    Science.gov (United States)

    Zhang, Linyao; Wu, Guilian; Yang, Jingyuan; Jia, Shuangrui; Zhang, Wei; Sun, Weiqing

    2018-01-01

    Aiming at the lack of a comprehensive evaluation of the distribution network, based on the existing distribution network evaluation index system, combined with the basic principles of constructing the evaluation index, put forward a new evaluation index system of distribution network capacity. This paper is mainly based on the total supply capability of the distribution network, combining single index and various factors, into a multi-evaluation index of the distribution network, thus forming a reasonable index system, and various indicators of rational quantification make the evaluation results more intuitive. In order to have a comprehensive judgment of distribution network, this paper uses weights to analyse the importance of each index, verify the rationality of the index system through the example, it is proved that the rationality of the index system, so as to guide the direction of distribution network planning.

  5. Development of vortex model with realistic axial velocity distribution

    International Nuclear Information System (INIS)

    Ito, Kei; Ezure, Toshiki; Ohshima, Hiroyuki

    2014-01-01

    A vortex is considered as one of significant phenomena which may cause gas entrainment (GE) and/or vortex cavitation in sodium-cooled fast reactors. In our past studies, the vortex is assumed to be approximated by the well-known Burgers vortex model. However, the Burgers vortex model has a simple but unreal assumption that the axial velocity component is horizontally constant, while in real the free surface vortex has the axial velocity distribution which shows large gradient in radial direction near the vortex center. In this study, a new vortex model with realistic axial velocity distribution is proposed. This model is derived from the steady axisymmetric Navier-Stokes equation as well as the Burgers vortex model, but the realistic axial velocity distribution in radial direction is considered, which is defined to be zero at the vortex center and to approach asymptotically to zero at infinity. As the verification, the new vortex model is applied to the evaluation of a simple vortex experiment, and shows good agreements with the experimental data in terms of the circumferential velocity distribution and the free surface shape. In addition, it is confirmed that the Burgers vortex model fails to calculate accurate velocity distribution with the assumption of uniform axial velocity. However, the calculation accuracy of the Burgers vortex model can be enhanced close to that of the new vortex model in consideration of the effective axial velocity which is calculated as the average value only in the vicinity of the vortex center. (author)

  6. On the second spherical harmonics of the cosmics ray angular distribution

    International Nuclear Information System (INIS)

    Kota, J.

    1974-12-01

    In order to describe the semi-diurnal variation of the cosmic ray intensity the convection-diffusion theory has been extended by considering the second moments of cosmic ray angular distribution and those of the statistical Boltzmann equation. The quadrupole moment of the directional distribution has been represented by a symmetric traceloss tensor whose elements correspond to the five independent spherical harmonics of second order. The results are basically in agreement with the earlier published ones. However, by contrast with these earlier results, in the present model a different particle flux is predicted from the directions along the magnetic field and normal to the ecliptic plane, respectively, and the interplanetary magnetic field lines are being bent and diverging. The second harmonics of the anisotropy depend on the global feature of the mean free path between the sun and the earth. Arguments are also brought forward that a sunward stream along the interplanetary magnetic field lines gives rise to a distribution of the pitch angle type. (Sz.Z.)

  7. Evaluation of the photocathode laser transverse distribution

    Energy Technology Data Exchange (ETDEWEB)

    Saisa-ard, Chaipattana [DESY, Zeuthen (Germany); Chiang Mai Univ., Chiang Mai (Thailand); Krasilnikov, Mikhail; Vashchenko, Grygorii [DESY, Zeuthen (Germany)

    2016-07-01

    Many years experience of electron source developments at the photo injector test facility at DESY in Zeuthen (PITZ) show that the photocathode laser is the one of major tools to produce high brightness electron beams. The transverse distribution of the laser on the photocathode plays a significant role in the high brightness photo injector optimization. However, the imperfections in the laser beam profile according to the deviation from a radially homogeneous profile directly result in transversely distorted charged particle distributions. This includes inhomogeneous core as well as transverse halo which is due to not sharp edges around the core. The laser transverse distribution is measured at PITZ using a virtual cathode:this is a CCD camera located at the position which is optically equivalent to the photocathode position (so called virtual cathode). An algorithm is developed for the evaluation of the experimentally obtained transverse profiles. It fits a flat-top or an inhomogeneous rotational symmetric core with exponentially decaying tails to an experimental distribution. The MATLAB script with implemented algorithm is applied to a set of measured transverse laser distributions. Results of the analysis will be presented.

  8. Negative density-distribution relationship in butterflies

    Directory of Open Access Journals (Sweden)

    Kotiaho Janne S

    2005-03-01

    Full Text Available Abstract Background Because "laws of nature" do not exist in ecology, much of the foundations of community ecology rely on broad statistical generalisations. One of the strongest generalisations is the positive relationship between density and distribution within a given taxonomic assemblage; that is, locally abundant species are more widespread than locally sparse species. Several mechanisms have been proposed to create this positive relationship, and the testing of these mechanisms is attracting increasing attention. Results We report a strong, but counterintuitive, negative relationship between density and distribution in the butterfly fauna of Finland. With an exceptionally comprehensive data set (data includes all 95 resident species in Finland and over 1.5 million individuals, we have been able to submit several of the mechanisms to powerful direct empirical testing. Without exception, we failed to find evidence for the proposed mechanisms creating a positive density-distribution relationship. On the contrary, we found that many of the mechanisms are equally able to generate a negative relationship. Conclusion We suggest that one important determinant of density-distribution relationships is the geographical location of the study: on the edge of a distribution range, suitable habitat patches are likely to be more isolated than in the core of the range. In such a situation, only the largest and best quality patches are likely to be occupied, and these by definition can support a relatively dense population leading to a negative density-distribution relationship. Finally, we conclude that generalizations about the positive density-distribution relationship should be made more cautiously.

  9. Negative density-distribution relationship in butterflies.

    Science.gov (United States)

    Päivinen, Jussi; Grapputo, Alessandro; Kaitala, Veijo; Komonen, Atte; Kotiaho, Janne S; Saarinen, Kimmo; Wahlberg, Niklas

    2005-03-01

    Because "laws of nature" do not exist in ecology, much of the foundations of community ecology rely on broad statistical generalisations. One of the strongest generalisations is the positive relationship between density and distribution within a given taxonomic assemblage; that is, locally abundant species are more widespread than locally sparse species. Several mechanisms have been proposed to create this positive relationship, and the testing of these mechanisms is attracting increasing attention. We report a strong, but counterintuitive, negative relationship between density and distribution in the butterfly fauna of Finland. With an exceptionally comprehensive data set (data includes all 95 resident species in Finland and over 1.5 million individuals), we have been able to submit several of the mechanisms to powerful direct empirical testing. Without exception, we failed to find evidence for the proposed mechanisms creating a positive density-distribution relationship. On the contrary, we found that many of the mechanisms are equally able to generate a negative relationship. We suggest that one important determinant of density-distribution relationships is the geographical location of the study: on the edge of a distribution range, suitable habitat patches are likely to be more isolated than in the core of the range. In such a situation, only the largest and best quality patches are likely to be occupied, and these by definition can support a relatively dense population leading to a negative density-distribution relationship. Finally, we conclude that generalizations about the positive density-distribution relationship should be made more cautiously.

  10. Direct measurement of the W boson width

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Alberta U. /Simon Fraser U. /McGill U.; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, G.; /St. Petersburg, INP; Alton, A.; /Michigan U. /Northeastern U.

    2009-09-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.

  11. A simplistic pedagogical formulation of a thermal speed distribution ...

    Indian Academy of Sciences (India)

    approach, a logical extension of that proposed by Maxwell, will first ... framework that will help students to understand and derive the physics of relativistic ... Since any direction is as good as the others, the resultant distribution function j(·) must.

  12. Alternatives to the grid : distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    Kline, R.H. [Mercury Electric Corp., Calgary, AB (Canada)

    2001-07-01

    This presentation highlighted the merits of distributed generation. The author began by discussing energy drivers, touching on issues such as reliability, power quality, and the confusion resulting from the energy market, and energy costs. It was pointed out that the deregulation of the electricity market in Alberta was implemented on January 1, 1996 which has resulted in steady price increases ever since. A review of the options available to the customer begin by understanding baseload and peaking. The options then available are buying from the utility, buying through a reputable marketer, buying direct from a large scale independent power producer, on-site generation, and finally, distributed generation. The emphasis was placed on distributed generation defined as small scale on-site power generation and offers advantages such as the reduction/elimination of peak strain on grid, and offset/defer utility capital costs, therefore reducing total energy costs. Regulatory changes are making it easier than ever before to make the transition to distributed generation. The author briefly reviewed the advantages of microturbines then presented the Honeywell Parallon 75 TurboGenerator{sup TM}, reviewing its characteristics, operating modes and commercial applications. Examples were provided of successful microturbines installations throughout the country. figs.

  13. Modeling Uncertainty of Directed Movement via Markov Chains

    Directory of Open Access Journals (Sweden)

    YIN Zhangcai

    2015-10-01

    Full Text Available Probabilistic time geography (PTG is suggested as an extension of (classical time geography, in order to present the uncertainty of an agent located at the accessible position by probability. This may provide a quantitative basis for most likely finding an agent at a location. In recent years, PTG based on normal distribution or Brown bridge has been proposed, its variance, however, is irrelevant with the agent's speed or divergent with the increase of the speed; so they are difficult to take into account application pertinence and stability. In this paper, a new method is proposed to model PTG based on Markov chain. Firstly, a bidirectional conditions Markov chain is modeled, the limit of which, when the moving speed is large enough, can be regarded as the Brown bridge, thus has the characteristics of digital stability. Then, the directed movement is mapped to Markov chains. The essential part is to build step length, the state space and transfer matrix of Markov chain according to the space and time position of directional movement, movement speed information, to make sure the Markov chain related to the movement speed. Finally, calculating continuously the probability distribution of the directed movement at any time by the Markov chains, it can be get the possibility of an agent located at the accessible position. Experimental results show that, the variance based on Markov chains not only is related to speed, but also is tending towards stability with increasing the agent's maximum speed.

  14. Investigation of Spatial Distribution Properties of Mid-Infrared ...

    African Journals Online (AJOL)

    The spatial distribution properties of quantum cascade lasers with emission wavelengths around 7 µm were measured. In addition, the emission profile on a plane orthogonal to the propagation axis of the beam were measured and the full width at half maximum (FWHM) on the orthogonal and lateral directions calculated.

  15. Direct measurements of neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Holzschuh, E [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    The direct measurements have so far given no indication for a nonzero (positive) mass of any of the three known neutrinos. The experiments measuring the tau and the muon neutrino are good shape. The tritium experiments are in an unfortunate situation. It is unclear to me whether the problems are experimental or theoretical or a combination of both. The electronic final states distribution have been calculated, but the results have never been tested experimentally. The most important question to be answered is about the validity of the sudden approximation. (author) 9 figs., 2 tabs., 16 refs.

  16. Slip heterogeneity, body-wave spectra, and directivity of earthquake ruptures

    OpenAIRE

    Bernard, P.; Herrero, A.

    1994-01-01

    We present a broadband kinematic model based on a self-similar k-square distribution of the coseismic slip, with an instantaneous rise-time and a constant rupture velocity. The phase of the slip spectrum at high wave number is random. This model generates an ?-squared body-wave radiation, and a particular directivity factor C2d scaling the amplitude of the body-wave spectra, where Cd is the standard directivity factor. Considering the source models with a propagating pulse and a finite rise-t...

  17. NEWTPOIS- NEWTON POISSON DISTRIBUTION PROGRAM

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative poisson distribution program, NEWTPOIS, is one of two programs which make calculations involving cumulative poisson distributions. Both programs, NEWTPOIS (NPO-17715) and CUMPOIS (NPO-17714), can be used independently of one another. NEWTPOIS determines percentiles for gamma distributions with integer shape parameters and calculates percentiles for chi-square distributions with even degrees of freedom. It can be used by statisticians and others concerned with probabilities of independent events occurring over specific units of time, area, or volume. NEWTPOIS determines the Poisson parameter (lambda), that is; the mean (or expected) number of events occurring in a given unit of time, area, or space. Given that the user already knows the cumulative probability for a specific number of occurrences (n) it is usually a simple matter of substitution into the Poisson distribution summation to arrive at lambda. However, direct calculation of the Poisson parameter becomes difficult for small positive values of n and unmanageable for large values. NEWTPOIS uses Newton's iteration method to extract lambda from the initial value condition of the Poisson distribution where n=0, taking successive estimations until some user specified error term (epsilon) is reached. The NEWTPOIS program is written in C. It was developed on an IBM AT with a numeric co-processor using Microsoft C 5.0. Because the source code is written using standard C structures and functions, it should compile correctly on most C compilers. The program format is interactive, accepting epsilon, n, and the cumulative probability of the occurrence of n as inputs. It has been implemented under DOS 3.2 and has a memory requirement of 30K. NEWTPOIS was developed in 1988.

  18. A Distributed Ledger for Supply Chain Physical Distribution Visibility

    Directory of Open Access Journals (Sweden)

    Haoyan Wu

    2017-11-01

    Full Text Available Supply chains (SC span many geographies, modes and industries and involve several phases where data flows in both directions from suppliers, manufacturers, distributors, retailers, to customers. This data flow is necessary to support critical business decisions that may impact product cost and market share. Current SC information systems are unable to provide validated, pseudo real-time shipment tracking during the distribution phase. This information is available from a single source, often the carrier, and is shared with other stakeholders on an as-needed basis. This paper introduces an independent, crowd-validated, online shipment tracking framework that complements current enterprise-based SC management solutions. The proposed framework consists of a set of private distributed ledgers and a single blockchain public ledger. Each private ledger allows the private sharing of custody events among the trading partners in a given shipment. Privacy is necessary, for example, when trading high-end products or chemical and pharmaceutical products. The second type of ledger is a blockchain public ledger. It consists of the hash code of each private event in addition to monitoring events. The latter provide an independently validated immutable record of the pseudo real-time geolocation status of the shipment from a large number of sources using commuters-sourcing.

  19. Direct observation of cation distributions of ideal inverse spinel CoFe2O4 nanofibres and correlated magnetic properties

    KAUST Repository

    Zeng, Xue; Zhang, Junwei; Zhu, Shimeng; Deng, Xia; Ma, Hongbin; Zhang, Junli; Zhang, Qiang; Li, Peng; Xue, Desheng; Mellors, Nigel J; Zhang, Xixiang; Peng, Yong

    2017-01-01

    multiferroic heterostructures. Although we know that the distribution of cations (Fe3+ and Co2+) in a spinel structure governs its magnetic properties, their distribution in the so-called ideal inverse spinel structure of a ferrite, CoFe2O4, has not yet been

  20. A Deployment Scheme Based Upon Virtual Force for Directional Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chiu-Kuo Liang

    2015-11-01

    Full Text Available A directional sensor network is composed of many directional sensor nodes. Unlike conventional omni-directional sensors that always have an omni-angle of sensing range; directional sensors may have a limited angle of sensing range due to technical constraints or cost considerations. Area coverage is still an essential issue in a directional sensor network. In this paper, we study the area coverage problem in directional sensor networks with mobile sensors, which can move to the correct places to get high coverage. We present distributed self-deployment schemes of mobile sensors. After sensors are randomly deployed, each sensor calculates its next new location to move in order to obtain a better coverage than previous one. The locations of sensors are adjusted round by round so that the coverage is gradually improved. Based on the virtual force of the directional sensors, we design a scheme, namely Virtual force scheme. Simulation results show the effectiveness of our scheme in term of the coverage improvement.

  1. Irradiation distribution diagrams and their use for estimating collectable energy

    International Nuclear Information System (INIS)

    Ronnelid, M.; Karlsson, B.

    1997-01-01

    A method for summarising annual or seasonal solar irradiation data in irradiation distribution diagrams, including both direct and diffuse irradiation, is outlined. The practical use of irradiation distribution diagrams is discussed in the paper. Examples are given for the calculation of collectable irradiation on flat plate collectors or trough-like concentrators like the compound parabolic concentrator (CPC), and for the calculation of overhang geometries for windows to prevent overheating of buildings. (author)

  2. Direct numerical reconstruction of conductivities in three dimensions using scattering transforms

    DEFF Research Database (Denmark)

    Bikowski, Jutta; Knudsen, Kim; Mueller, Jennifer L

    2011-01-01

    A direct three-dimensional EIT reconstruction algorithm based on complex geometrical optics solutions and a nonlinear scattering transform is presented and implemented for spherically symmetric conductivity distributions. The scattering transform is computed both with a Born approximation and from...

  3. Application of HPCN to direct numerical simulation of turbulent flow

    NARCIS (Netherlands)

    Verstappen, RWCP; Veldman, AEP; van Waveren, GM; Hertzberger, B; Sloot, P

    1997-01-01

    This poster shows how HPCN can be used as a path-finding tool for turbulence research. The parallelization of direct numerical simulation of turbulent flow using the data-parallel model and Fortran 95 constructs is treated, both on a shared memory and a distributed memory computer.

  4. Simulating a Direction-Finder Search for an ELT

    Science.gov (United States)

    Bream, Bruce

    2005-01-01

    A computer program simulates the operation of direction-finding equipment engaged in a search for an emergency locator transmitter (ELT) aboard an aircraft that has crashed. The simulated equipment is patterned after the equipment used by the Civil Air Patrol to search for missing aircraft. The program is designed to be used for training in radio direction-finding and/or searching for missing aircraft without incurring the expense and risk of using real aircraft and ground search resources. The program places a hidden ELT on a map and enables the user to search for the location of the ELT by moving a 14 NASA Tech Briefs, March 2005 small aircraft image around the map while observing signal-strength and direction readings on a simulated direction- finding locator instrument. As the simulated aircraft is turned and moved on the map, the program updates the readings on the direction-finding instrument to reflect the current position and heading of the aircraft relative to the location of the ELT. The software is distributed in a zip file that contains an installation program. The software runs on the Microsoft Windows 9x, NT, and XP operating systems.

  5. Simple passive methods for the assessment of the directional and vertical distributions of wind-blown particulates

    International Nuclear Information System (INIS)

    Orza, J. A.G.; Cabello, M.; Mateo, J.

    2009-01-01

    We have designed and tested two types of passive collectors to study aeolian erosion in the field. The first passive sampler is a sticky pad that allows for directional particulate assessment by an automatic particle counting procedure. the second one features an omni-directional capture opening, and mass of retained particles is gravimetric ally quantified. Vertical arrays of these passive collectors have been constructed to obtain vertical profiles of the horizontal particle flux as a function of soil properties, nearby sources and wind speed. We present some first results from field campaigns. (Author) 3 refs.

  6. Smart Distribution Networks: A Review of Modern Distribution Concepts from a Planning Perspective

    Directory of Open Access Journals (Sweden)

    Syed Ali Abbas Kazmi

    2017-04-01

    Full Text Available Smart grids (SGs, as an emerging grid modernization concept, is spreading across diverse research areas for revolutionizing power systems. SGs realize new key concepts with intelligent technologies, maximizing achieved objectives and addressing critical issues that are limited in conventional grids. The SG modernization is more noticeable at the distribution grid level. Thus, the transformation of the traditional distribution network (DN into an intelligent one, is a vital dimension of SG research. Since future DNs are expected to be interconnected in nature and operation, hence traditional planning methods and tools may no longer be applicable. In this paper, the smart distribution network (SDN concept under the SG paradigm, has presented and reviewed from the planning perspective. Also, developments in the SDN planning process have been surveyed on the basis of SG package (SGP. The package presents a SDN planning foundation via major SG-enabling technologies (SGTF, anticipated functionalities (SGAF, new consumption models (MDC as potential SDN candidates, associated policies and pilot projects and multi-objective planning (MOP as a real-world optimization problem. In addition, the need for an aggregated SDN planning model has also been highlighted. The paper discusses recent notable related works, implementation activities, various issues/challenges and potential future research directions; all aiming at SDN planning.

  7. Impulse tests on distribution transformers protected by means of spark gaps

    Energy Technology Data Exchange (ETDEWEB)

    Pykaelae, M L; Palva, V [Helsinki Univ. of Technology, Otaniemi (Finland). High Voltage Institute; Niskanen, K [ABB Corporate Research, Vaasa (Finland)

    1998-12-31

    Distribution transformers in rural networks have to cope with transient overvoltages, even with those caused by the direct lightning strokes to the lines. In Finland the 24 kV network conditions, such as wooden pole lines, high soil resistivity and isolated neutral network, lead into fast transient overvoltages. Impulse testing of pole-mounted distribution transformers ({<=} 200 kVA) protected by means of spark gaps were studied. Different failure detection methods were used. Results can be used as background information for standardization work dealing with distribution transformers protected by means of spark gaps. (orig.) 9 refs.

  8. Impulse tests on distribution transformers protected by means of spark gaps

    Energy Technology Data Exchange (ETDEWEB)

    Pykaelae, M.L.; Palva, V. [Helsinki Univ. of Technology, Otaniemi (Finland). High Voltage Institute; Niskanen, K. [ABB Corporate Research, Vaasa (Finland)

    1997-12-31

    Distribution transformers in rural networks have to cope with transient overvoltages, even with those caused by the direct lightning strokes to the lines. In Finland the 24 kV network conditions, such as wooden pole lines, high soil resistivity and isolated neutral network, lead into fast transient overvoltages. Impulse testing of pole-mounted distribution transformers ({<=} 200 kVA) protected by means of spark gaps were studied. Different failure detection methods were used. Results can be used as background information for standardization work dealing with distribution transformers protected by means of spark gaps. (orig.) 9 refs.

  9. Distribution Grid Integration Costs Under High PV Penetrations Workshop |

    Science.gov (United States)

    utility business model and structure: policies and regulations, revenue requirements and investment Practices Panel 3: Future Directions in Grid Integration Cost-Benefit Analysis Determining Distribution Grid into Utility Planning Notes on Future Needs All speakers were asked to include their opinions on

  10. Spatial distributions of dose enhancement around a gold nanoparticle at several depths of proton Bragg peak

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jihun [Department of Radiation Oncology, Hokkaido University Graduate School of Medicine, Hokkaido University (Japan); Sutherland, Kenneth [Department of Medical Physics, Hokkaido University Graduate School of Medicine, Hokkaido University (Japan); Hashimoto, Takayuki [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine (Japan); Shirato, Hiroki [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine and Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University (Japan); Date, Hiroyuki, E-mail: date@hs.hokudai.ac.jp [Faculty of Health Sciences, Hokkaido University (Japan)

    2016-10-01

    Gold nanoparticles (GNPs) have been recognized as a promising candidate for a radiation sensitizer. A proton beam incident on a GNP can produce secondary electrons, resulting in an enhancement of the dose around the GNP. However, little is known about the spatial distribution of dose enhancement around the GNP, especially in the direction along the incident proton. The purpose of this study is to determine the spatial distribution of dose enhancement by taking the incident direction into account. Two steps of calculation were conducted using the Geant4 Monte Carlo simulation toolkit. First, the energy spectra of 100 and 195 MeV protons colliding with a GNP were calculated at the Bragg peak and three other depths around the peak in liquid water. Second, the GNP was bombarded by protons with the obtained energy spectra. Radial dose distributions were computed along the incident beam direction. The spatial distributions of the dose enhancement factor (DEF) and subtracted dose (D{sub sub}) were then evaluated. The spatial DEF distributions showed hot spots in the distal radial region from the proton beam axis. The spatial D{sub sub} distribution isotropically spread out around the GNP. Low energy protons caused higher and wider dose enhancement. The macroscopic dose enhancement in clinical applications was also evaluated. The results suggest that the consideration of the spatial distribution of GNPs in treatment planning will maximize the potential of GNPs.

  11. Directional selection in temporally replicated studies is remarkably consistent.

    Science.gov (United States)

    Morrissey, Michael B; Hadfield, Jarrod D

    2012-02-01

    Temporal variation in selection is a fundamental determinant of evolutionary outcomes. A recent paper presented a synthetic analysis of temporal variation in selection in natural populations. The authors concluded that there is substantial variation in the strength and direction of selection over time, but acknowledged that sampling error would result in estimates of selection that were more variable than the true values. We reanalyze their dataset using techniques that account for the necessary effect of sampling error to inflate apparent levels of variation and show that directional selection is remarkably constant over time, both in magnitude and direction. Thus we cannot claim that the available data support the existence of substantial temporal heterogeneity in selection. Nonetheless, we conject that temporal variation in selection could be important, but that there are good reasons why it may not appear in the available data. These new analyses highlight the importance of applying techniques that estimate parameters of the distribution of selection, rather than parameters of the distribution of estimated selection (which will reflect both sampling error and "real" variation in selection); indeed, despite availability of methods for the former, focus on the latter has been common in synthetic reviews of the aspects of selection in nature, and can lead to serious misinterpretations. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  12. A Rational Procedure for Determination of Directional Individual Design Wave Heights

    DEFF Research Database (Denmark)

    Sterndorff, M.; Sørensen, John Dalsgaard

    2001-01-01

    For code-based LRFD and for reliability-based assessment of offshore structures such as steel platforms it is essential that consistent directional and omnidirectional probability distributions for the maximum significant wave height, the maximum individual wave height, and the maximum individual...

  13. Seed distribution of four co-occurring grasses around Artemisia halodendron shrubs in a sandy habitat

    Science.gov (United States)

    Li, Feng-Rui; Zhao, Wen-Zhi; Kang, Ling-Fen; Liu, Ji-Liang; Huang, Zhi-Gang; Wang, Qi

    2009-05-01

    In a natural population of the perennial semi-shrub Artemisia halodendron in a shifting sandy habitat in the Horqin Desert of eastern Inner Mongolia, six isolated adult A. halodendron individuals of similar canopy size were chosen as target plants. The density of seeds in the top 5 cm soil depth around shrubs was measured using transects aligned to the four main wind directions and at different distances from the shrub base on both the windward and leeward sides. The effects of shrub presence on seed distribution of four co-occurring grasses were examined by linking seed distribution to seed traits. Of the four species, Setaris viridis and Eragrostis pilosa had small but similar seed mass, while Chloris virgata and Aristida adscensionis had large but similar seed mass. The species were grouped into two cohorts: small-seeded vs. large-seeded cohorts, and shrub presence effects on seed distribution of both cohorts were examined. We found marked difference in the seed distribution pattern among species, especially between the small-seeded and large-seeded cohorts. The small-seeded cohort had significantly higher seed accumulation on the windward than the leeward sides in the most and least prevailing wind directions and much higher seed accumulation on the leeward than the windward sides in the second and third most prevailing wind directions, while opposite patterns occurred in the large-seeded cohort. Four species also showed marked variation in the seed distribution pattern among transects and between windward and leeward sides of each transect. This study provided further evidence that shrubs embedded in a matrix of herbaceous plants is a key cause of spatial heterogeneity in seed availability of herbaceous species. However, seed distribution responses to the presence of shrubs will vary with species as well as with wind direction, sampling position (windward vs. leeward sides of the shrub) and distance from the shrub.

  14. Marketing and Distributive Education. Food Marketing Curriculum Guide

    Science.gov (United States)

    Northern Illinois Univ., DeKalb. Dept. of Business Education and Administration Services.

    This document is one of four curriculum guides designed to provide the curriculum coordinator with a basis for planning a comprehensive program in the field of marketing as well as to provide marketing and distributive education teachers with maximum flexibility. Introductory information provides directions for using the guide and information on…

  15. A new stochastic algorithm for inversion of dust aerosol size distribution

    Science.gov (United States)

    Wang, Li; Li, Feng; Yang, Ma-ying

    2015-08-01

    Dust aerosol size distribution is an important source of information about atmospheric aerosols, and it can be determined from multiwavelength extinction measurements. This paper describes a stochastic inverse technique based on artificial bee colony (ABC) algorithm to invert the dust aerosol size distribution by light extinction method. The direct problems for the size distribution of water drop and dust particle, which are the main elements of atmospheric aerosols, are solved by the Mie theory and the Lambert-Beer Law in multispectral region. And then, the parameters of three widely used functions, i.e. the log normal distribution (L-N), the Junge distribution (J-J), and the normal distribution (N-N), which can provide the most useful representation of aerosol size distributions, are inversed by the ABC algorithm in the dependent model. Numerical results show that the ABC algorithm can be successfully applied to recover the aerosol size distribution with high feasibility and reliability even in the presence of random noise.

  16. Markov chain Monte Carlo analysis to constrain dark matter properties with directional detection

    International Nuclear Information System (INIS)

    Billard, J.; Mayet, F.; Santos, D.

    2011-01-01

    Directional detection is a promising dark matter search strategy. Indeed, weakly interacting massive particle (WIMP)-induced recoils would present a direction dependence toward the Cygnus constellation, while background-induced recoils exhibit an isotropic distribution in the Galactic rest frame. Taking advantage of these characteristic features, and even in the presence of a sizeable background, it has recently been shown that data from forthcoming directional detectors could lead either to a competitive exclusion or to a conclusive discovery, depending on the value of the WIMP-nucleon cross section. However, it is possible to further exploit these upcoming data by using the strong dependence of the WIMP signal with: the WIMP mass and the local WIMP velocity distribution. Using a Markov chain Monte Carlo analysis of recoil events, we show for the first time the possibility to constrain the unknown WIMP parameters, both from particle physics (mass and cross section) and Galactic halo (velocity dispersion along the three axis), leading to an identification of non-baryonic dark matter.

  17. Measurements of droplet size distribution and in-cylinder mixture formation from a slit injector in a direct-injection gasoline engine

    Science.gov (United States)

    Moon, S.; Choi, J.; Yeom, K.; Bae, C.

    2007-10-01

    The droplet size distribution and in-cylinder mixture formation of a slit injector were investigated under varied fuel temperature and air flow conditions. This variance in fuel temperature and air flow represents the altered spray momentum and external forces acting upon the spray. Phase Doppler anemometry (PDA) was used to investigate the effect of fuel temperature and air flow on droplet size distribution. The in-cylinder mixture formation process and the factors affecting the in-cylinder mixture distribution were analyzed under various fuel temperature and air flow conditions using laser induced fluorescence (LIF). When the fuel temperature and air flow velocity increased, the smaller droplets were entrained to the upper and central parts of the spray altering the initial droplet size distribution. The reduced spray momentum decreased the spray penetration in the combustion chamber, and the interaction between the spray and piston bowl was degraded. This phenomenon eventually caused a relatively lean and dispersed mixture distribution near the spark plug at high fuel temperatures. The optimal spray momentum and external force depend on the fuel quantity (air-fuel ratio) and piston bowl shape. Consequently, the spray momentum and the external forces acting upon the spray should be optimized to form the stoichiometric and well-distributed mixture near the spark plug.

  18. Measurements of droplet size distribution and in-cylinder mixture formation from a slit injector in a direct-injection gasoline engine

    International Nuclear Information System (INIS)

    Moon, S; Choi, J; Yeom, K; Bae, C

    2007-01-01

    The droplet size distribution and in-cylinder mixture formation of a slit injector were investigated under varied fuel temperature and air flow conditions. This variance in fuel temperature and air flow represents the altered spray momentum and external forces acting upon the spray. Phase Doppler anemometry (PDA) was used to investigate the effect of fuel temperature and air flow on droplet size distribution. The in-cylinder mixture formation process and the factors affecting the in-cylinder mixture distribution were analyzed under various fuel temperature and air flow conditions using laser induced fluorescence (LIF). When the fuel temperature and air flow velocity increased, the smaller droplets were entrained to the upper and central parts of the spray altering the initial droplet size distribution. The reduced spray momentum decreased the spray penetration in the combustion chamber, and the interaction between the spray and piston bowl was degraded. This phenomenon eventually caused a relatively lean and dispersed mixture distribution near the spark plug at high fuel temperatures. The optimal spray momentum and external force depend on the fuel quantity (air-fuel ratio) and piston bowl shape. Consequently, the spray momentum and the external forces acting upon the spray should be optimized to form the stoichiometric and well-distributed mixture near the spark plug

  19. Analysis of logistic distribution performance of good supply from PT. Mentari Trans Nusantara distribution center to branches using Smart PLS 3.0

    Science.gov (United States)

    Endrawati, Titin; Siregar, M. Tirtana

    2018-03-01

    PT Mentari Trans Nusantara is a company engaged in the distribution of goods from the manufacture of the product to the distributor branch of the customer so that the product distribution must be controlled directly from the PT Mentari Trans Nusantara Center for faster delivery process. Problems often occur on the expedition company which in charge in sending the goods although it has quite extensive networking. The company is less control over logistics management. Meanwhile, logistics distribution management control policy will affect the company's performance in distributing products to customer distributor branches and managing product inventory in distribution center. PT Mentari Trans Nusantara is an expedition company which engaged in good delivery, including in Jakarta. Logistics management performance is very important due to its related to the supply of goods from the central activities to the branches based oncustomer demand. Supply chain management performance is obviously depends on the location of both the distribution center and branches, the smoothness of transportation in the distribution and the availability of the product in the distribution center to meet the demand in order to avoid losing sales. This study concluded that the company could be more efficient and effective in minimizing the risks of loses by improve its logistic management.

  20. Energy Distributions from Three-Body Decaying Many-Body Resonances

    International Nuclear Information System (INIS)

    Alvarez-Rodriguez, R.; Jensen, A. S.; Fedorov, D. V.; Fynbo, H. O. U.; Garrido, E.

    2007-01-01

    We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0 + and 1 + resonances in 12 C populated in β decays. These states are dominated by sequential, through the 8 Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the ''dynamic'' evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed

  1. Agent-based unified approach for thermal and voltage constraint management in LV distribution network

    NARCIS (Netherlands)

    Haque, A.N.M.M.; Nguyen, H.P.; Vo, T.; Bliek, F.W.

    2016-01-01

    Rapid proliferation of the distributed energy resources (DERs) poses operational challenges for the low-voltage (LV) distribution networks in terms of thermal overloading of the network assets along with voltage limit violations at the connection points. A number of market-based and direct control

  2. Beam profiles in the nonwedged direction for dynamic wedges

    International Nuclear Information System (INIS)

    Lydon, J.M.; Rykers, K.L.

    1996-01-01

    One feature of the dynamic wedge is the improved flatness of the beam profile in the nonwedged direction when compared to fixed wedges. Profiles in the nonwedged direction for fixed wedges show a fall-off in dose away from the central axis when compared to the open field profile. This study will show that there is no significant difference between open field profiles and nonwedged direction profiles for dynamically wedged beams. The implications are that the dynamic wedge offers an improved dose distribution in the nonwedged direction that can be modelled by approximating the dynamically wedged field to an open field. This is possible as both the profiles and depth doses of the dynamically wedged fields match those of the open fields, if normalized to d max of the same field size. For treatment planning purposes the effective wedge factor (EWF) provides a normalization factor for the open field depth dose data set. Data will be presented to demonstrate that the EWF shows relatively little variation with depth and can be treated as being independent of field size in the nonwedged direction. (author)

  3. Direct versus indirect detection of supersymmetric dark matter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document gathers the slides that were presented during the workshop 'direct versus indirect detection of supersymmetric dark matter'(about 30 contributions). This workshop intended to bring together people from the particle theory community, astrophysicists and cosmologists, as well as experimentalists involved in the detection of dark matter. The aim is to generate a discussion about current and future strategies for detection of SUSY dark matter (with focus, but not exclusively, on neutralinos). Complementarities between accelerator, direct and indirect searches as well as a comparison between the uncertainties in direct and indirect searches of dark matter, are supposed to be discussed. Among the issues which will be addressed are: -) the crucial questions related to the structure of galaxies (local dark matter density, clumping, anomalous velocity distributions, etc.) ; -) the possibilities offered by the present and future experimental facilities for direct and indirect (photon, neutrino) searches; -) the potential for the discovery of SUSY at LHC and beyond; and -) the parameterization of the SUSY breaking models beyond the minimal versions.

  4. Inclusions and mechanical behavior in the short transverse direction

    International Nuclear Information System (INIS)

    Aubert, H.; Bouleau, M.; Laniesse, J.; Lelong, C.; Pigoury, M.

    1977-01-01

    The variables liable to characterize the distribution of inclusions in plates, and the relationships between the mechanical properties and the fatigue behavior in, on the one hand, the short transverse direction, and, on the other hand, the inclusions are studied. A decoherence is shown between inclusions and matrix as the cause of the failure by lamellar tearing [fr

  5. Spatial pattern of foreign direct investment of China's textile enterprises

    Institute of Scientific and Technical Information of China (English)

    2018-01-01

    China textile industry has achieved encouraging achievements, becoming the primary industry of the integration of investment, production, consumption, employment increase and foreign exchange earnings. On the basis of reviewing studies on foreign direct investment of domestic textile enterprises, this paper come up with the structure analysis framework of spatial strategies of foreign investment of China's textile enterprises with the methods of statistical information, field research and interviews of senior managers. Besides, this paper analyze the spatial distribution and industry choices of foreign direct investment of China's textile enterprises.

  6. Locating Direction Finders in a Generalized Search and Rescue Network

    Science.gov (United States)

    1991-03-01

    David A . Drake and Alfred B. Marsb. Conv-ersation at NationalI Security Agenc, 29 September 1990. 7. Daskin , Mark S. " A M-admum Fpeced Co-:efing...91 7 19 134 .flT/GORjEnSj9I-M LOCATING DIRECTION FIND’RS IN A GENERALIZED SEARCH AND RESCUE NETWORK THESIS Jean M. Steppe Captain, USAF AFIT/GOR/EN S...91-Mk-7 APPROVED FOR PUBLIC RELI ASE: DISTRIBUTION UNLIMITED. 1191-05734 .. 91.. .7 19 134 i i . nMIGOR4M.S/91-MI LOCATING DIRECTION FINDERS IW A

  7. Distributed Monitoring of Voltage Collapse Sensitivity Indices

    OpenAIRE

    Simpson-Porco, John W.; Bullo, Francesco

    2016-01-01

    The assessment of voltage stability margins is a promising direction for wide-area monitoring systems. Accurate monitoring architectures for long-term voltage instability are typically centralized and lack scalability, while completely decentralized approaches relying on local measurements tend towards inaccuracy. Here we present distributed linear algorithms for the online computation of voltage collapse sensitivity indices. The computations are collectively performed by processors embedded ...

  8. Experimental distribution of entanglement with separable carriers

    Science.gov (United States)

    Fedrizzi, Alessandro; Zuppardo, Margherita; Gillett, Geoff; Broome, Matthew; de Almeida, Marcelo; Paternostro, Mauro; White, Andrew; Paterek, Tomasz

    2014-03-01

    Quantum networks will allow us to overcome distance limitations in quantum communication, and to share quantum computing tasks between remote quantum processors. The key requirement for quantum networking is the distribution of entanglement between nodes. Surprisingly, entanglement can be generated across a network without directly being communicated between nodes. In contrast to information gain, which cannot exceed the communicated information, the entanglement gain is bounded by the communicated quantum discord, a more general measure of quantum correlation that includes but is not limited to entanglement. Here we report an experiment in which two communicating parties who share three initially separable photonic qubits are entangled by exchange of a carrier photon that is not entangled with either party at all times. We show that distributing entanglement with separable carriers is resilient to noise and in some cases becomes the only way of distributing entanglement over noisy environments.

  9. Development of sample size allocation program using hypergeometric distribution

    International Nuclear Information System (INIS)

    Kim, Hyun Tae; Kwack, Eun Ho; Park, Wan Soo; Min, Kyung Soo; Park, Chan Sik

    1996-01-01

    The objective of this research is the development of sample allocation program using hypergeometric distribution with objected-oriented method. When IAEA(International Atomic Energy Agency) performs inspection, it simply applies a standard binomial distribution which describes sampling with replacement instead of a hypergeometric distribution which describes sampling without replacement in sample allocation to up to three verification methods. The objective of the IAEA inspection is the timely detection of diversion of significant quantities of nuclear material, therefore game theory is applied to its sampling plan. It is necessary to use hypergeometric distribution directly or approximate distribution to secure statistical accuracy. Improved binomial approximation developed by Mr. J. L. Jaech and correctly applied binomial approximation are more closer to hypergeometric distribution in sample size calculation than the simply applied binomial approximation of the IAEA. Object-oriented programs of 1. sample approximate-allocation with correctly applied standard binomial approximation, 2. sample approximate-allocation with improved binomial approximation, and 3. sample approximate-allocation with hypergeometric distribution were developed with Visual C ++ and corresponding programs were developed with EXCEL(using Visual Basic for Application). 8 tabs., 15 refs. (Author)

  10. Distributions of Conductance and Shot Noise and Associated Phase Transitions

    International Nuclear Information System (INIS)

    Vivo, Pierpaolo; Majumdar, Satya N.; Bohigas, Oriol

    2008-01-01

    For a chaotic cavity with two identical leads each supporting N channels, we compute analytically, for large N, the full distribution of the conductance and the shot noise power and show that in both cases there is a central Gaussian region flanked on both sides by non-Gaussian tails. The distribution is weakly singular at the junction of Gaussian and non-Gaussian regimes, a direct consequence of two phase transitions in an associated Coulomb gas problem

  11. Signatures of Earth-scattering in the direct detection of Dark Matter

    DEFF Research Database (Denmark)

    Kavanagh, Bradley J.; Catena, Riccardo; Kouvaris, Chris

    2017-01-01

    Direct detection experiments search for the interactions of Dark Matter (DM) particles with nuclei in terrestrial detectors. But if these interactions are sufficiently strong, DM particles may scatter in the Earth, affecting their distribution in the lab. We present a new analytic calculation...

  12. Momentum distributions of selected rare-gas atoms probed by intense femtosecond laser pulses

    DEFF Research Database (Denmark)

    Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2011-01-01

    We provide a direct comparison between numerical and experimental (Rudenko et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 L407) photoelectron momentum distributions in strong-field ionization of selected rare-gas atoms (He, Ne and Ar), probed by femtosecond linearly polarized laser pulses. The cal......We provide a direct comparison between numerical and experimental (Rudenko et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 L407) photoelectron momentum distributions in strong-field ionization of selected rare-gas atoms (He, Ne and Ar), probed by femtosecond linearly polarized laser pulses....... The calculations are performed by solving the time-dependent Schrödinger equation within the single-active-electron approximation, and focal-volume effects are taken into account by appropriately averaging the results. The resulting momentum distributions are in quantitative agreement with the experimental...

  13. The prevalence and age distribution of peripheral pulmonary ...

    African Journals Online (AJOL)

    This autopsy-based study defined the prevalence and age distribution of peripheral pulmonary hamartomas in 47635 southern African miners examined between 1975 and 1988. The prevalence rate for white miners was 7,5/1000 and for black miners 1,1/1 000. When directly standardised to the white men in the general ...

  14. Collective properties of injection-induced earthquake sequences: 1. Model description and directivity bias

    Science.gov (United States)

    Dempsey, David; Suckale, Jenny

    2016-05-01

    Induced seismicity is of increasing concern for oil and gas, geothermal, and carbon sequestration operations, with several M > 5 events triggered in recent years. Modeling plays an important role in understanding the causes of this seismicity and in constraining seismic hazard. Here we study the collective properties of induced earthquake sequences and the physics underpinning them. In this first paper of a two-part series, we focus on the directivity ratio, which quantifies whether fault rupture is dominated by one (unilateral) or two (bilateral) propagating fronts. In a second paper, we focus on the spatiotemporal and magnitude-frequency distributions of induced seismicity. We develop a model that couples a fracture mechanics description of 1-D fault rupture with fractal stress heterogeneity and the evolving pore pressure distribution around an injection well that triggers earthquakes. The extent of fault rupture is calculated from the equations of motion for two tips of an expanding crack centered at the earthquake hypocenter. Under tectonic loading conditions, our model exhibits a preference for unilateral rupture and a normal distribution of hypocenter locations, two features that are consistent with seismological observations. On the other hand, catalogs of induced events when injection occurs directly onto a fault exhibit a bias toward ruptures that propagate toward the injection well. This bias is due to relatively favorable conditions for rupture that exist within the high-pressure plume. The strength of the directivity bias depends on a number of factors including the style of pressure buildup, the proximity of the fault to failure and event magnitude. For injection off a fault that triggers earthquakes, the modeled directivity bias is small and may be too weak for practical detection. For two hypothetical injection scenarios, we estimate the number of earthquake observations required to detect directivity bias.

  15. Measurement of power distribution in FCA-HCLWR core (Phase-1)

    International Nuclear Information System (INIS)

    Ohno, Akio; Osugi, Toshitaka; Satoh, Kunio

    1991-11-01

    In the report are described experiments with zone-type mock-up cores (FCA XIV) which consisted of uranium fuels and polystilene plates, assembled at FCA (Fast Critical Assembly), to study a series of physical characteristics for high conversion light water reactors. As one example of those characteristics, power distributions were measured by a γ-counting method in the mock-up cores by changing parametrically voidage states of the moderator, volume ratio of moderator to fuel and fuel enrichment. Fine structures of fission rate in a plate-array cell having strong heterogeneities were obtained at the center cell of the core to investigate the validity of the SRAC code for the analysis of the high conversion light water reactor. Furthermore infinite multiplication factors K ∞ which are an important physical parameter were derived from calculated migration areas and bucklings of each direction. This was obtained by fitting the measured power distributions into a cosine function. Calculated power distributions of radial directions overestimate largely the measure ones, while those of axial directions agree well with the measured values. Calculations on fine structure of fission ratio in the cell follow generally the measured values, but it is recognized that the calculation underestimates the measurement in a soft neutron spectrum core. As for infinite multiplication factors K ∞ , calculated values by the SRAC code agree within experimental errors with measured ones. No trend is observed on different voidage state of moderator and fuel enrichment in the limit of this experiment. (author)

  16. STRATEGIES TO PROMOTE WINE PRODUCTS ON FOREIGN MARKETS THROUGH THE NETWORK DISTRIBUTION OF GOODS

    Directory of Open Access Journals (Sweden)

    Stefan MATEI

    2013-06-01

    Full Text Available Distribution of goods has evolved in two main directions that seem contradictory : on the one hand, the mass distribution was fully developed in terms of distribution facilities, logistics, comfort, and standardization of goods and services, on the other hand, the increased competition and customer loyalty has prompted the development of marketing techniques based on developing long-term relationships between the company and customers. Often this relationship is created and maintained through personalized offers, a unique combination of services and through direct contact with customers.These contradictory trends are reproduced in the distribution and consumption of wine. It is considered to be more than a physical product. From one point of view, the wine is not regarded as a simply physical product. The value of wine increases due to its tradition, trademark, country and region of origin, processing method, as well as the consumer’s knowledge and sensitivity. On the other side, the wine is one of the world’s most popular alcoholic beverages.

  17. KAPSIES: A program for the calculation of multi-step direct reaction cross sections

    International Nuclear Information System (INIS)

    Koning, A.J.; Akkermans, J.M.

    1994-09-01

    We present a program for the calculation of continuum cross sections, sepctra, angular distributions and analyzing powers according to various quantum-mechanical theories for statistical multi-step direct nuclear reactions. (orig.)

  18. Reliability evaluation of smart distribution grids

    OpenAIRE

    Kazemi, Shahram

    2011-01-01

    The term "Smart Grid" generally refers to a power grid equipped with the advanced technologies dedicated for purposes such as reliability improvement, ease of control and management, integrating of distributed energy resources and electricity market operations. Improving the reliability of electric power delivered to the end users is one of the main targets of employing smart grid technologies. The smart grid investments targeted for reliability improvement can be directed toward the generati...

  19. Angular distribution of laser ablation plasma

    International Nuclear Information System (INIS)

    Kondo, K.; Kanesue, T.; Dabrowski, R.; Okamura, M.

    2010-01-01

    An expansion of a laser induced plasma is fundamental and important phenomena in a laser ion source. To understand the expanding direction, an array of Langmuir probes were employed. The chosen ion for the experiment was Ag 1+ which was created by a second harmonics of a Nd-YAG laser. The obtained angular distribution was about ±10 degree. This result also indicates a proper positioning of a solenoid magnet which enhances ion beam current.

  20. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

    Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

    2017-09-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  1. Parton Distributions in the Higgs Boson Era

    CERN Document Server

    Rojo, Juan

    2013-01-01

    Parton distributions are an essential ingredient of the LHC program. PDFs are relevant for precision Standard Model measurements, for Higgs boson characterization as well as for New Physics searches. In this contribution I review recent progress in the determination of the parton distributions of the proton during the last year. Important developments include the impact of new LHC measurements to pin down poorly known PDFs, studies of theoretical uncertainties, higher order calculations for processes relevant for PDF determinations, PDF benchmarking exercises with LHC data, as well as methodological and statistical improvements in the global analysis framework. I conclude with some speculative considerations about future directions in PDF determinations from the theory point of view.

  2. Measurement of two-dimensional thermal neutron flux in a water phantom and evaluation of dose distribution characteristics

    International Nuclear Information System (INIS)

    Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Horiguchi, Yoji

    2001-03-01

    To evaluate nitrogen dose, boron dose and gamma-ray dose occurred by neutron capture reaction of the hydrogen at the medical irradiation, two-dimensional distribution of the thermal neutron flux is very important because these doses are proportional to the thermal neutron distribution. This report describes the measurement of the two-dimensional thermal neutron distribution in a head water phantom by neutron beams of the JRR-4 and evaluation of the dose distribution characteristic. Thermal neutron flux in the phantom was measured by gold wire placed in the spokewise of every 30 degrees in order to avoid the interaction. Distribution of the thermal neutron flux was also calculated using two-dimensional Lagrange's interpolation program (radius, angle direction) developed this time. As a result of the analysis, it was confirmed to become distorted distribution which has annular peak at outside of the void, though improved dose profile of the deep direction was confirmed in the case which the radiation field in the phantom contains void. (author)

  3. Fission meter and neutron detection using poisson distribution comparison

    Science.gov (United States)

    Rowland, Mark S; Snyderman, Neal J

    2014-11-18

    A neutron detector system and method for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. Comparison of the observed neutron count distribution with a Poisson distribution is performed to distinguish fissile material from non-fissile material.

  4. Subjective Belief Distributions and the Characterization of Economic Literacy

    DEFF Research Database (Denmark)

    Di Girolamo, Amalia; Harrison, Glenn W.; Lau, Morten

    2015-01-01

    the confidence that an individual has about their knowledge of some fact. We consider literacy across several financial and economic domains. We find considerable demographic heterogeneity in the degree of literacy. We also measure the degree of consistency within a sample about their knowledge, even when......We characterize the literacy of an individual in a domain by their elicited subjective belief distribution over the possible responses to a question posed in that domain. By eliciting the distribution, rather than just the answers to true/false or multiple choice questions, we can directly measure...

  5. Fuzzy extractors for continuous distributions

    OpenAIRE

    Buhan, I.R.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.

    2006-01-01

    We show that there is a direct relation between the maximum length of the keys extracted from biometric data and the error rates of the biometric system. The length of the bio-key depends on the amount of distinguishing information that can be extracted from the source data. This information can be used a-priori to evaluate the potential of the biometric data in the context of a specific cryptographic application. We model the biometric data more naturally as a continuous distribution and we ...

  6. Multipath interference test method for distributed amplifiers

    Science.gov (United States)

    Okada, Takahiro; Aida, Kazuo

    2005-12-01

    A method for testing distributed amplifiers is presented; the multipath interference (MPI) is detected as a beat spectrum between the multipath signal and the direct signal using a binary frequency shifted keying (FSK) test signal. The lightwave source is composed of a DFB-LD that is directly modulated by a pulse stream passing through an equalizer, and emits the FSK signal of the frequency deviation of about 430MHz at repetition rate of 80-100 kHz. The receiver consists of a photo-diode and an electrical spectrum analyzer (ESA). The base-band power spectrum peak appeared at the frequency of the FSK frequency deviation can be converted to amount of MPI using a calibration chart. The test method has improved the minimum detectable MPI as low as -70 dB, compared to that of -50 dB of the conventional test method. The detailed design and performance of the proposed method are discussed, including the MPI simulator for calibration procedure, computer simulations for evaluating the error caused by the FSK repetition rate and the fiber length under test and experiments on singlemode fibers and distributed Raman amplifier.

  7. Control and homogenization of oxygen distribution in Si crystals by the novel technique: electromagnetic Czochralski method (EMCZ)

    Science.gov (United States)

    Watanabe, Masahito; Eguchi, Minoru; Hibiya, Taketoshi

    1999-07-01

    A novel method for control and homogenization oxygen distribution in silicon crystals by using electromagnetic force (EMF) to rotate the melt without crucible rotation has been developed. We call it electromagnetic Czochralski method. An EMF in the azimuthal direction is generated in the melt by the interaction between an electric current through the melt in the radial direction and a vertical magnetic field. (B). The rotation rate (ωm) of the silicon melt is continuously changed from 0 to over 105 rpm under I equals 0 to 8 A and B equals 0 to 0.1 T. Thirty-mm-diameter silicon single crystals free of dislocations could be grown under several conditions. The oxygen concentration in the crystals was continuously changed from 1 X 1017 to 1 X 1018 atoms/cm3 with increase of melt rotation by electromagnetic force. The homogeneous oxygen distributions in the radial directions were achieved. The continuous change of oxygen concentration and the homogenization of oxygen distribution along the radial direction are attributed to the control of the diffusion-boundary-layer at both the melt/crucible and crystal/melt by forced flow due to the EMF. This new method would be useful for growth of the large-diameter silicon crystals with a homogeneous distribution of oxygen.

  8. Direct seismic detection of gas hydrates using multi-component seismology : a case study from the mid-Norwegian margin

    Energy Technology Data Exchange (ETDEWEB)

    Bunz, S.; Mienert, J. [Tromso Univ., Tromso (Norway). Dept. of Geology; Chand, S. [Norwegian Geological Survey, Trondheim (Norway)

    2008-07-01

    Gas hydrates are important as a possible future energy resource, in submarine landsliding and in global climate change as they contain more carbon than any other global reservoir and are plentiful on continental margins worldwide. It is therefore necessary to identify and map the distribution of gas hydrates in a fast and basin-wide approach. Information about the distribution of gas hydrates can be obtained using multi-component seismology. In the marine environment shear waves (S-waves) can be generated by conversion from a downward-propagating compressional wave (P-wave) upon reflection at a sedimentary interface. The upward-propagating S-wave can be recorded at the ocean floor using vertical and horizontal geophones. On the mid-Norwegian margin, a combined analysis of the independently obtained parameters, P-wave velocity and Vp/Vs-ratio, of ocean-bottom cable data enables the direct detection of gas hydrates with higher certainty and assessment of their grain-scale distribution and its controlling parameters. In order to directly image gas hydrates and to directly assess their grain-scale distribution, a model was developed to evaluate the distribution of the ratio of P- and S-wave velocities, Vp/Vs, along the ocean-bottom cable line. The study also evaluated possible controlling mechanisms for the distribution of gas hydrates. The paper provided detailed information on the distribution of gas hydrates and gas within the sediments through analyses of seismic velocities, obtained from multi-channel or ocean-bottom seismic data. It was concluded that gas hydrates are distributed both with and without affecting the shear strength of the sediments. 13 refs., 6 figs.

  9. Direct utilization of geothermal energy: a layman's guide. Geothermal Resources Council special report No. 8

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.N.; Lund, J.W. (eds.)

    1979-01-01

    The following subjects are covered: nature and distribution of geothermal energy; exploration, confirmation, and evaluation of the resource; reservoir development and management; utilization; economics of direct-use development; financing direct-use projects; and legal, institutional, and environmental aspects. (MHR)

  10. Observation of distorted Maxwell-Boltzmann distribution of epithermal ions in LHD

    Science.gov (United States)

    Ida, K.; Kobayashi, T.; Yoshinuma, M.; Akiyama, T.; Tokuzawa, T.; Tsuchiya, H.; Itoh, K.; LHD Experiment Group

    2017-12-01

    A distorted Maxwell-Boltzmann distribution of epithermal ions is observed associated with the collapse of energetic ions triggered by the tongue shaped deformation. The tongue shaped deformation is characterized by the plasma displacement localized in the toroidal, poloidal, and radial directions at the non-rational magnetic flux surface in toroidal plasma. Moment analysis of the ion velocity distribution measured with charge exchange spectroscopy is studied in order to investigate the impact of tongue event on ion distribution. A clear non-zero skewness (3rd moment) and kurtosis (4th moment -3) of ion velocity distribution in the epithermal region (within three times of thermal velocity) is observed after the tongue event. This observation indicates the clear evidence of the distortion of ion velocity distribution from Maxwell-Boltzmann distribution. This distortion from Maxwell-Boltzmann distribution is observed in one-third of plasma minor radius region near the plasma edge and disappears in the ion-ion collision time scale.

  11. Size and spatial distribution of micropores in SBA-15 using CM-SANS

    International Nuclear Information System (INIS)

    Pollock, Rachel A.; Walsh, Brenna R.; Fry, Jason A.; Ghampson, Tyrone; Centikol, Ozgul; Melnichenko, Yuri B.; Kaiser, Helmut; Pynn, Roger; Frederick, Brian G.

    2011-01-01

    Diffraction intensity analysis of small-angle neutron scattering measurements of dry SBA-15 have been combined with nonlocal density functional theory (NLDFT) analysis of nitrogen desorption isotherms to characterize the micropore, secondary mesopore, and primary mesopore structure. The radial dependence of the scattering length density, which is sensitive to isolated surface hydroxyls, can only be modeled if the NLDFT pore size distribution is distributed relatively uniformly throughout the silica framework, not localized in a 'corona' around the primary mesopores. Contrast matching-small angle neutron scattering (CM-SANS) measurements, using water, decane, tributylamine, cyclohexane, and isooctane as direct probes of the size of micropores indicate that the smallest pores in SBA-15 have diameter between 5.7 and 6.2 (angstrom). Correlation of the minimum pore size with the onset of the micropore size distribution provides direct evidence that the shape of the smallest micropores is cylinderlike, which is consistent with their being due to unraveling of the polymer template.

  12. Investigations on 3-dimensional temperature distribution in a FLATCON-type CPV module

    Science.gov (United States)

    Wiesenfarth, Maike; Gamisch, Sebastian; Kraus, Harald; Bett, Andreas W.

    2013-09-01

    The thermal flow in a FLATCON®-type CPV module is investigated theoretically and experimentally. For the simulation a model in the computational fluid dynamics (CFD) software SolidWorks Flow Simulation was established. In order to verify the simulation results the calculated and measured temperatures were compared assuming the same operating conditions (wind speed and direction, direct normal irradiance (DNI) and ambient temperature). Therefore, an experimental module was manufactured and equipped with temperature sensors at defined positions. In addition, the temperature distribution on the back plate of the module was displayed by infrared images. The simulated absolute temperature and the distribution compare well with an average deviation of only 3.3 K to the sensor measurements. Finally, the validated model was used to investigate the influence of the back plate material on the temperature distribution by replacing the glass material by aluminum. The simulation showed that it is important to consider heat dissipation by radiation when designing a CPV module.

  13. Investigating The Neutron Flux Distribution Of The Miniature Neutron Source Reactor MNSR Type

    International Nuclear Information System (INIS)

    Nguyen Hoang Hai; Do Quang Binh

    2011-01-01

    Neutron flux distribution is the important characteristic of nuclear reactor. In this article, four energy group neutron flux distributions of the miniature neutron source reactor MNSR type versus radial and axial directions are investigated in case the control rod is fully withdrawn. In addition, the effect of control rod positions on the thermal neutron flux distribution is also studied. The group constants for all reactor components are generated by the WIMSD code, and the neutron flux distributions are calculated by the CITATION code. The results show that the control rod positions only affect in the planning area for distribution in the region around the control rod. (author)

  14. Gamma-ray angular distribution and correlation measurement. II

    International Nuclear Information System (INIS)

    Twin, P.J.

    1975-01-01

    Angular correlations of γ-rays following nuclear reactions depend, in general, on some alignment of the γ-emitting initial state. The methods of alignment are briefly discussed and then the techniques and experimental methods associated with direct angular distributions, particle-gamma correlations, gamma-gamma correlations and linear polarization correlations are dealt with. Finally the inherent ambiguities which arise when different spin and delta values give identical correlations are discussed for the simple direct and particle-gamma correlations together with the question whether the larger information content of gamma-gamma and linear polarization correlations can resolve these ambiguities. (Auth.)

  15. Distribution of spinal neuronal networks controlling forward and backward locomotion.

    Science.gov (United States)

    Merkulyeva, Natalia; Veshchitskii, Aleksandr; Gorsky, Oleg; Pavlova, Natalia; Zelenin, Pavel V; Gerasimenko, Yury; Deliagina, Tatiana G; Musienko, Pavel

    2018-04-20

    Higher vertebrates, including humans, are capable not only of forward (FW) locomotion but also of walking in other directions relative to the body axis [backward (BW), sideways, etc.]. While the neural mechanisms responsible for controlling FW locomotion have been studied in considerable detail, the mechanisms controlling steps in other directions are mostly unknown. The aim of the present study was to investigate the distribution of spinal neuronal networks controlling FW and BW locomotion. First, we applied electrical epidural stimulation (ES) to different segments of the spinal cord from L2 to S2 to reveal zones triggering FW and BW locomotion in decerebrate cats of either sex. Second, to determine the location of spinal neurons activated during FW and BW locomotion, we used c-fos immunostaining. We found that the neuronal networks responsible for FW locomotion were distributed broadly in the lumbosacral spinal cord and could be activated by ES of any segment from L3 to S2. By contrast, networks generating BW locomotion were activated by ES of a limited zone from the caudal part of L5 to the caudal part of L7. In the intermediate part of the gray matter within this zone, a significantly higher number of c- fos -positive interneurons was revealed in BW-stepping cats compared with FW-stepping cats. We suggest that this region of the spinal cord contains the network that determines the BW direction of locomotion. Significance Statement Sequential and single steps in various directions relative to the body axis [forward (FW), backward (BW), sideways, etc.] are used during locomotion and to correct for perturbations, respectively. The mechanisms controlling step direction are unknown. In the present study, for the first time we compared the distributions of spinal neuronal networks controlling FW and BW locomotion. Using a marker to visualize active neurons, we demonstrated that in the intermediate part of the gray matter within L6 and L7 spinal segments

  16. Efficient Parallel Algorithm For Direct Numerical Simulation of Turbulent Flows

    Science.gov (United States)

    Moitra, Stuti; Gatski, Thomas B.

    1997-01-01

    A distributed algorithm for a high-order-accurate finite-difference approach to the direct numerical simulation (DNS) of transition and turbulence in compressible flows is described. This work has two major objectives. The first objective is to demonstrate that parallel and distributed-memory machines can be successfully and efficiently used to solve computationally intensive and input/output intensive algorithms of the DNS class. The second objective is to show that the computational complexity involved in solving the tridiagonal systems inherent in the DNS algorithm can be reduced by algorithm innovations that obviate the need to use a parallelized tridiagonal solver.

  17. Air flow distribution in and around a single-sided naturally ventilated room

    Energy Technology Data Exchange (ETDEWEB)

    Eftekhari, M.M.; Marjanovic, L.D.; Pinnock, D.J. [Loughborough University (United Kingdom). Dept. of Civil and Building Engineering

    2002-03-01

    The objective of this research is to compare calculated and measured air flow distributions inside a test room which is naturally ventilated. The test room is situated in a relatively sheltered location and to visualise the resultant local wind pattern around the room for all prevailing wind directions, wind tunnel trials were carried out. Both the wind tunnel and full-scale measurements show that the wind direction at the test cell was generally restricted to either a westerly or an easterly direction. To investigate air flow inside the room, the air pressures and velocities across the openings together with indoor air temperature and velocity at four locations and six different levels are measured. The experimental results demonstrate that for both winter and summer the air was entering the test room at bottom and leaving at the top louvre. Separate air flow and thermal modelling programs are used to predict the spatial distribution of the air flow and thermal comfort. The air flow distribution was predicted using a network air flow program. The predicted flow showed similar trends and the simulation results were in agreement with the measured data. An explicit finite-difference thermal modeling simulation package was used to predict the thermal comfort indices.(author)

  18. Modelling Wind for Wind Farm Layout Optimization Using Joint Distribution of Wind Speed and Wind Direction

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    Reliable wind modelling is of crucial importance for wind farm development. The common practice of using sector-wise Weibull distributions has been found inappropriate for wind farm layout optimization. In this study, we propose a simple and easily implementable method to construct joint distribu...

  19. Fluctuations in projectile fragment distributions from 1 GeV/nucleon Au + C multifragmentation

    International Nuclear Information System (INIS)

    Elliott, J.B.; Gilkes, M.L.; Hauger, A.; Hirsch, A.S.

    1993-01-01

    Fluctuations in cluster distributions play an important role in distinguishing critical and non-critical cluster forming phenomena. The magnitude of the reduced variance (γ 2 ) of a cluster distribution is a direct measure of the size of its fluctuations. Preliminary examinations of γ 2 are made for cluster distributions from 1 GeV/nucleon Au+C data obtained in the EOS experiment at the Bevalac. Values of γ 2 are compared to those from percolation and statistical multifragmentation models

  20. Effects of interface pressure distribution on human sleep quality.

    Directory of Open Access Journals (Sweden)

    Zongyong Chen

    Full Text Available High sleep quality promotes efficient performance in the following day. Sleep quality is influenced by environmental factors, such as temperature, light, sound and smell. Here, we investigated whether differences in the interface pressure distribution on healthy individuals during sleep influenced sleep quality. We defined four types of pressure models by differences in the area distribution and the subjective feelings that occurred when participants slept on the mattresses. One type of model was showed "over-concentrated" distribution of pressure; one was displayed "over-evenly" distributed interface pressure while the other two models were displayed intermediate distribution of pressure. A polysomnography analysis demonstrated an increase in duration and proportion of non-rapid-eye-movement sleep stages 3 and 4, as well as decreased number of micro-arousals, in subjects sleeping on models with pressure intermediately distributed compared to models with over-concentrated or over-even distribution of pressure. Similarly, higher scores of self-reported sleep quality were obtained in subjects sleeping on the two models with intermediate pressure distribution. Thus, pressure distribution, at least to some degree, influences sleep quality and self-reported feelings of sleep-related events, though the underlying mechanisms remain unknown. The regulation of pressure models imposed by external sleep environment may be a new direction for improving sleep quality. Only an appropriate interface pressure distribution is beneficial for improving sleep quality, over-concentrated or -even distribution of pressure do not help for good sleep.

  1. A NEW STATISTICAL PERSPECTIVE TO THE COSMIC VOID DISTRIBUTION

    International Nuclear Information System (INIS)

    Pycke, J-R; Russell, E.

    2016-01-01

    In this study, we obtain the size distribution of voids as a three-parameter redshift-independent log-normal void probability function (VPF) directly from the Cosmic Void Catalog (CVC). Although many statistical models of void distributions are based on the counts in randomly placed cells, the log-normal VPF that we obtain here is independent of the shape of the voids due to the parameter-free void finder of the CVC. We use three void populations drawn from the CVC generated by the Halo Occupation Distribution (HOD) Mocks, which are tuned to three mock SDSS samples to investigate the void distribution statistically and to investigate the effects of the environments on the size distribution. As a result, it is shown that void size distributions obtained from the HOD Mock samples are satisfied by the three-parameter log-normal distribution. In addition, we find that there may be a relation between the hierarchical formation, skewness, and kurtosis of the log-normal distribution for each catalog. We also show that the shape of the three-parameter distribution from the samples is strikingly similar to the galaxy log-normal mass distribution obtained from numerical studies. This similarity between void size and galaxy mass distributions may possibly indicate evidence of nonlinear mechanisms affecting both voids and galaxies, such as large-scale accretion and tidal effects. Considering the fact that in this study, all voids are generated by galaxy mocks and show hierarchical structures in different levels, it may be possible that the same nonlinear mechanisms of mass distribution affect the void size distribution.

  2. Parametric Probability Distribution Functions for Axon Diameters of Corpus Callosum

    Directory of Open Access Journals (Sweden)

    Farshid eSepehrband

    2016-05-01

    Full Text Available Axon diameter is an important neuroanatomical characteristic of the nervous system that alters in the course of neurological disorders such as multiple sclerosis. Axon diameters vary, even within a fiber bundle, and are not normally distributed. An accurate distribution function is therefore beneficial, either to describe axon diameters that are obtained from a direct measurement technique (e.g., microscopy, or to infer them indirectly (e.g., using diffusion-weighted MRI. The gamma distribution is a common choice for this purpose (particularly for the inferential approach because it resembles the distribution profile of measured axon diameters which has been consistently shown to be non-negative and right-skewed. In this study we compared a wide range of parametric probability distribution functions against empirical data obtained from electron microscopy images. We observed that the gamma distribution fails to accurately describe the main characteristics of the axon diameter distribution, such as location and scale of the mode and the profile of distribution tails. We also found that the generalized extreme value distribution consistently fitted the measured distribution better than other distribution functions. This suggests that there may be distinct subpopulations of axons in the corpus callosum, each with their own distribution profiles. In addition, we observed that several other distributions outperformed the gamma distribution, yet had the same number of unknown parameters; these were the inverse Gaussian, log normal, log logistic and Birnbaum-Saunders distributions.

  3. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

    Science.gov (United States)

    Mantzouki, Evanthia; Lürling, Miquel; Fastner, Jutta; de Senerpont Domis, Lisette; Wilk-Woźniak, Elżbieta; Koreivienė, Judita; Seelen, Laura; Teurlincx, Sven; Verstijnen, Yvon; Krztoń, Wojciech; Walusiak, Edward; Karosienė, Jūratė; Kasperovičienė, Jūratė; Savadova, Ksenija; Vitonytė, Irma; Cillero-Castro, Carmen; Budzyńska, Agnieszka; Goldyn, Ryszard; Kozak, Anna; Rosińska, Joanna; Szeląg-Wasielewska, Elżbieta; Domek, Piotr; Jakubowska-Krepska, Natalia; Kwasizur, Kinga; Messyasz, Beata; Pełechaty, Aleksandra; Pełechaty, Mariusz; Kokocinski, Mikolaj; García-Murcia, Ana; Real, Monserrat; Romans, Elvira; Noguero-Ribes, Jordi; Duque, David Parreño; Fernández-Morán, Elísabeth; Karakaya, Nusret; Häggqvist, Kerstin; Demir, Nilsun; Beklioğlu, Meryem; Filiz, Nur; Levi, Eti E.; Iskin, Uğur; Bezirci, Gizem; Tavşanoğlu, Ülkü Nihan; Özhan, Koray; Gkelis, Spyros; Panou, Manthos; Fakioglu, Özden; Avagianos, Christos; Kaloudis, Triantafyllos; Çelik, Kemal; Yilmaz, Mete; Marcé, Rafael; Catalán, Nuria; Bravo, Andrea G.; Buck, Moritz; Colom-Montero, William; Mustonen, Kristiina; Pierson, Don; Yang, Yang; Raposeiro, Pedro M.; Gonçalves, Vítor; Antoniou, Maria G.; Tsiarta, Nikoletta; McCarthy, Valerie; Perello, Victor C.; Feldmann, Tõnu; Laas, Alo; Panksep, Kristel; Tuvikene, Lea; Gagala, Ilona; Mankiewicz-Boczek, Joana; Yağcı, Meral Apaydın; Çınar, Şakir; Çapkın, Kadir; Yağcı, Abdulkadir; Cesur, Mehmet; Bilgin, Fuat; Bulut, Cafer; Uysal, Rahmi; Obertegger, Ulrike; Boscaini, Adriano; Flaim, Giovanna; Salmaso, Nico; Cerasino, Leonardo; Richardson, Jessica; Visser, Petra M.; Verspagen, Jolanda M. H.; Karan, Tünay; Soylu, Elif Neyran; Maraşlıoğlu, Faruk; Napiórkowska-Krzebietke, Agnieszka; Ochocka, Agnieszka; Pasztaleniec, Agnieszka; Antão-Geraldes, Ana M.; Vasconcelos, Vitor; Morais, João; Vale, Micaela; Köker, Latife; Akçaalan, Reyhan; Albay, Meriç; Špoljarić Maronić, Dubravka; Stević, Filip; Žuna Pfeiffer, Tanja; Fonvielle, Jeremy; Straile, Dietmar; Rothhaupt, Karl-Otto; Hansson, Lars-Anders; Urrutia-Cordero, Pablo; Bláha, Luděk; Geriš, Rodan; Fránková, Markéta; Koçer, Mehmet Ali Turan; Alp, Mehmet Tahir; Remec-Rekar, Spela; Elersek, Tina; Triantis, Theodoros; Zervou, Sevasti-Kiriaki; Hiskia, Anastasia; Haande, Sigrid; Skjelbred, Birger; Madrecka, Beata; Nemova, Hana; Drastichova, Iveta; Chomova, Lucia; Edwards, Christine; Sevindik, Tuğba Ongun; Tunca, Hatice; Önem, Burçin; Aleksovski, Boris; Krstić, Svetislav; Vucelić, Itana Bokan; Nawrocka, Lidia; Salmi, Pauliina; Machado-Vieira, Danielle; de Oliveira, Alinne Gurjão; Delgado-Martín, Jordi; García, David; Cereijo, Jose Luís; Gomà, Joan; Trapote, Mari Carmen; Vegas-Vilarrúbia, Teresa; Obrador, Biel; Grabowska, Magdalena; Karpowicz, Maciej; Chmura, Damian; Úbeda, Bárbara; Gálvez, José Ángel; Özen, Arda; Christoffersen, Kirsten Seestern; Warming, Trine Perlt; Kobos, Justyna; Mazur-Marzec, Hanna; Pérez-Martínez, Carmen; Ramos-Rodríguez, Eloísa; Arvola, Lauri; Alcaraz-Párraga, Pablo; Toporowska, Magdalena; Pawlik-Skowronska, Barbara; Niedźwiecki, Michał; Pęczuła, Wojciech; Leira, Manel; Hernández, Armand; Moreno-Ostos, Enrique; Blanco, José María; Rodríguez, Valeriano; Montes-Pérez, Jorge Juan; Palomino, Roberto L.; Rodríguez-Pérez, Estela; Carballeira, Rafael; Camacho, Antonio; Picazo, Antonio; Rochera, Carlos; Santamans, Anna C.; Ferriol, Carmen; Romo, Susana; Soria, Juan Miguel; Dunalska, Julita; Sieńska, Justyna; Szymański, Daniel; Kruk, Marek; Kostrzewska-Szlakowska, Iwona; Jasser, Iwona; Žutinić, Petar; Gligora Udovič, Marija; Plenković-Moraj, Anđelka; Frąk, Magdalena; Bańkowska-Sobczak, Agnieszka; Wasilewicz, Michał; Özkan, Korhan; Maliaka, Valentini; Kangro, Kersti; Grossart, Hans-Peter; Paerl, Hans W.; Carey, Cayelan C.; Ibelings, Bas W.

    2018-04-13

    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  4. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

    Directory of Open Access Journals (Sweden)

    Evanthia Mantzouki

    2018-04-01

    Full Text Available Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins. Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a and cytotoxins (e.g., cylindrospermopsin due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  5. Exploring light mediators with low-threshold direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kahlhoefer, Felix [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); RWTH Aachen Univ. (Germany). Inst. for Theoretical Particle Physics and Cosmology; Kulkarni, Suchita [Oesterreichische Akademie der Wissenschaften, Vienna (Austria). Inst. fuer Hochenergiephysik; Wild, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2017-11-15

    We explore the potential of future cryogenic direct detection experiments to determine the properties of the mediator that communicates the interactions between dark matter and nuclei. Due to their low thresholds and large exposures, experiments like CRESST-III, SuperCDMS SNOLAB and EDELWEISS-III will have excellent capability to reconstruct mediator masses in the MeV range for a large class of models. Combining the information from several experiments further improves the parameter reconstruction, even when taking into account additional nuisance parameters related to background uncertainties and the dark matter velocity distribution. These observations may offer the intriguing possibility of studying dark matter self-interactions with direct detection experiments.

  6. Exploring light mediators with low-threshold direct detection experiments

    International Nuclear Information System (INIS)

    Kahlhoefer, Felix

    2017-11-01

    We explore the potential of future cryogenic direct detection experiments to determine the properties of the mediator that communicates the interactions between dark matter and nuclei. Due to their low thresholds and large exposures, experiments like CRESST-III, SuperCDMS SNOLAB and EDELWEISS-III will have excellent capability to reconstruct mediator masses in the MeV range for a large class of models. Combining the information from several experiments further improves the parameter reconstruction, even when taking into account additional nuisance parameters related to background uncertainties and the dark matter velocity distribution. These observations may offer the intriguing possibility of studying dark matter self-interactions with direct detection experiments.

  7. Decentralized Resource Management in Distributed Computer Systems.

    Science.gov (United States)

    1982-02-01

    directly exchanging user state information. Eventcounts and sequencers correspond to semaphores in the sense that synchronization primitives are used to...and techniques are required to achieve synchronization in distributed computers without reliance on any centralized entity such as a semaphore ...known solutions to the access synchronization problem was Dijkstra’s semaphore [12]. The importance of the semaphore is that it correctly addresses the

  8. Frequency and distribution of highway crossings by Kenai Peninsula brown bears

    OpenAIRE

    Graves, Tabitha A.; Farley, Sean; Servheen, Christopher

    2003-01-01

    Highway construction and expansion through bear habitat can negatively affect brown bear populations. Highway structures can decrease habitat availability through habitat loss and restricted access, roads often displace animals and cause re-direction of natural movements, and highways can act as barriers to decrease gene flow. Lastly, highway traffic can cause direct bear and human mortality through car-animal collisions. We examined the spatial and temporal distribution of brown bear crossin...

  9. Distribution of Exhaled Contaminants and Personal Exposure in a Room using Three Different Air Distribution Strategies

    DEFF Research Database (Denmark)

    Olmedo, Inés; Nielsen, Peter V.; Adana, M. Ruiz de

    2012-01-01

    The level of exposure to human exhaled contaminants in a room depends not only on the air distribution system but also on people’s different positions, the distance between them, people’s activity level and height, direction of exhalation, and the surrounding temperature and temperature gradient...... between the manikins are changed to study the influence on the level of exposure. The results show that the air exhaled by a manikin flows a longer distance with a higher concentration in case of displacement ventilation than in the other two cases, indicating a significant exposure to the contaminants....... Human exhalation is studied in detail for different distribution systems: displacement and mixing ventilation as well as a system without mechanical ventilation. Two thermal manikins breathing through the mouth are used to simulate the exposure to human exhaled contaminants. The position and distance...

  10. Simple parametrizations of parton distributions with Q$^{2}$ dependence given by asymptotic freedom

    CERN Document Server

    Buras, Andrzej J

    1978-01-01

    The Q/sup 2/ dependence of parton distributions as given by asymptotically free gauge theories can be represented by simple analytic expressions. In particular the sea distributions can be read directly from the first two moments. The results are compared with the SLAC ep data and with the recent Fermilab mu p data. The agreement is good. (32 refs).

  11. Differentially Private Distributed Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Glenn A.

    2016-12-11

    The growth of the Internet of Things (IoT) creates the possibility of decentralized systems of sensing and actuation, potentially on a global scale. IoT devices connected to cloud networks can offer Sensing and Actuation as a Service (SAaaS) enabling networks of sensors to grow to a global scale. But extremely large sensor networks can violate privacy, especially in the case where IoT devices are mobile and connected directly to the behaviors of people. The thesis of this paper is that by adapting differential privacy (adding statistically appropriate noise to query results) to groups of geographically distributed sensors privacy could be maintained without ever sending all values up to a central curator and without compromising the overall accuracy of the data collected. This paper outlines such a scheme and performs an analysis of differential privacy techniques adapted to edge computing in a simulated sensor network where ground truth is known. The positive and negative outcomes of employing differential privacy in distributed networks of devices are discussed and a brief research agenda is presented.

  12. Coping with distributed computing

    International Nuclear Information System (INIS)

    Cormell, L.

    1992-09-01

    The rapid increase in the availability of high performance, cost-effective RISC/UNIX workstations has been both a blessing and a curse. The blessing of having extremely powerful computing engines available on the desk top is well-known to many users. The user has tremendous freedom, flexibility, and control of his environment. That freedom can, however, become the curse of distributed computing. The user must become a system manager to some extent, he must worry about backups, maintenance, upgrades, etc. Traditionally these activities have been the responsibility of a central computing group. The central computing group, however, may find that it can no longer provide all of the traditional services. With the plethora of workstations now found on so many desktops throughout the entire campus or lab, the central computing group may be swamped by support requests. This talk will address several of these computer support and management issues by providing some examples of the approaches taken at various HEP institutions. In addition, a brief review of commercial directions or products for distributed computing and management will be given

  13. Optimizing electrical distribution systems

    International Nuclear Information System (INIS)

    Scott, W.G.

    1990-01-01

    Electrical utility distribution systems are in the middle of an unprecedented technological revolution in planning, design, maintenance and operation. The prime movers of the revolution are the major economic shifts that affect decision making. The major economic influence on the revolution is the cost of losses (technical and nontechnical). The vehicle of the revolution is the computer, which enables decision makers to examine alternatives in greater depth and detail than their predecessors could. The more important elements of the technological revolution are: system planning, computers, load forecasting, analytical systems (primary systems, transformers and secondary systems), system losses and coming technology. The paper is directed towards the rather unique problems encountered by engineers of utilities in developing countries - problems that are being solved through high technology, such as the recent World Bank-financed engineering computer system for Sri Lanka. This system includes a DEC computer, digitizer, plotter and engineering software to model the distribution system via a digitizer, analyse the system and plot single-line diagrams. (author). 1 ref., 4 tabs., 6 figs

  14. Probability distributions for Markov chain based quantum walks

    Science.gov (United States)

    Balu, Radhakrishnan; Liu, Chaobin; Venegas-Andraca, Salvador E.

    2018-01-01

    We analyze the probability distributions of the quantum walks induced from Markov chains by Szegedy (2004). The first part of this paper is devoted to the quantum walks induced from finite state Markov chains. It is shown that the probability distribution on the states of the underlying Markov chain is always convergent in the Cesaro sense. In particular, we deduce that the limiting distribution is uniform if the transition matrix is symmetric. In the case of a non-symmetric Markov chain, we exemplify that the limiting distribution of the quantum walk is not necessarily identical with the stationary distribution of the underlying irreducible Markov chain. The Szegedy scheme can be extended to infinite state Markov chains (random walks). In the second part, we formulate the quantum walk induced from a lazy random walk on the line. We then obtain the weak limit of the quantum walk. It is noted that the current quantum walk appears to spread faster than its counterpart-quantum walk on the line driven by the Grover coin discussed in literature. The paper closes with an outlook on possible future directions.

  15. Improved Testing of Distributed Lag Model in Presence of ...

    African Journals Online (AJOL)

    The finite distributed lag models (DLM) are often used in econometrics and statistics. Application of the ordinary least square (OLS) directly on the DLM for estimation may have serious problems. To overcome these problems, some alternative estimation procedures are available in the literature. One popular method to ...

  16. Extent and Distribution of Groundwater Resources in Parts of ...

    African Journals Online (AJOL)

    The extent and distribution of groundwater resources in parts of Anambra State, Nigeria has been investigated. The results show that the study area is directly underlain by four different geological formations including, Alluvial Plain Sands, Ogwashi-Asaba Formation, Ameki/Nanka Sands and Imo Shale, with varying water ...

  17. Saddlepoint approximation to the distribution of the total distance of the continuous time random walk

    Science.gov (United States)

    Gatto, Riccardo

    2017-12-01

    This article considers the random walk over Rp, with p ≥ 2, where a given particle starts at the origin and moves stepwise with uniformly distributed step directions and step lengths following a common distribution. Step directions and step lengths are independent. The case where the number of steps of the particle is fixed and the more general case where it follows an independent continuous time inhomogeneous counting process are considered. Saddlepoint approximations to the distribution of the distance from the position of the particle to the origin are provided. Despite the p-dimensional nature of the random walk, the computations of the saddlepoint approximations are one-dimensional and thus simple. Explicit formulae are derived with dimension p = 3: for uniformly and exponentially distributed step lengths, for fixed and for Poisson distributed number of steps. In these situations, the high accuracy of the saddlepoint approximations is illustrated by numerical comparisons with Monte Carlo simulation. Contribution to the "Topical Issue: Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  18. Redistribution of contaminants from pig slurry after direct injection into soil

    DEFF Research Database (Denmark)

    Amin, Mostofa; Bech, T B; Forslund, A

    2010-01-01

    The redistribution of pig manure-borne contaminants after direct injection to soil was investigated in a field study. The spatial distribution of Escherichia coli, Salmonella Typhimurium Bacteriophage 28B and other slurry components in and around the injection slit was measured on day 0.15, 1, 6...

  19. A centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria.

    Science.gov (United States)

    Choi, Goro; Jung, Jae Hwan; Park, Byung Hyun; Oh, Seung Jun; Seo, Ji Hyun; Choi, Jong Seob; Kim, Do Hyun; Seo, Tae Seok

    2016-06-21

    In this study, we developed a centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria contaminated milk samples. The microdevice was designed to contain identical triplicate functional units and each unit has four reaction chambers, thereby making it possible to perform twelve direct-RPA reactions simultaneously. The integrated microdevice consisted of two layers: RPA reagents were injected in the top layer, while spiked milk samples with food poisoning bacteria were loaded into sample reservoirs in the bottom layer. For multiplex bacterial detection, the target gene-specific primers and probes were dried in each reaction chamber. The introduced samples and reagents could be equally aliquoted and dispensed into each reaction chamber by centrifugal force, and then the multiplex direct-RPA reaction was executed. The target genes of bacteria spiked in milk could be amplified at 39 °C without a DNA extraction step by using the direct-RPA cocktails, which were a combination of a direct PCR buffer and RPA enzymes. As the target gene amplification proceeded, the increased fluorescence signals coming from the reaction chambers were recorded in real-time at an interval of 2 min. The entire process, including the sample distribution, the direct-RPA reaction, and the real-time analysis, was accomplished with a custom-made portable genetic analyzer and a miniaturized optical detector. Monoplex, duplex, and triplex food poisoning bacteria (Salmonella enterica, Escherichia coli O157:H7, and Vibrio parahaemolyticus) detection was successfully performed with a detection sensitivity of 4 cells per 3.2 μL of milk samples within 30 min. By implementing the direct-PRA on the miniaturized centrifugal microsystem, the on-site food poisoning bacteria analysis would be feasible with high speed, sensitivity, and multiplicity.

  20. NE seeks to sell power directly to customers

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Nuclear Electric, the state-owned company that operates nuclear power stations in England and Wales, has applied to compete directly with privatized electricity generating companies in the sale of electricity to major customers. Since its formation in 1990, NE has had to sell all of its electrical output through the so-called pool operated by the National Grid Company, and then to 12 regional distribution companies that have franchises for about 75 percent of electricity consumption in their regions. On the other hand, the two large companies that took over the fossil-fuel power stations at the time of privatization, and other new independent companies that are building combined-cycle gas-turbine plants, are allowed to conclude supply contracts directly with large industrial customers