WorldWideScience

Sample records for cumulative frequency distributions

  1. Cumulative Poisson Distribution Program

    Science.gov (United States)

    Bowerman, Paul N.; Scheuer, Ernest M.; Nolty, Robert

    1990-01-01

    Overflow and underflow in sums prevented. Cumulative Poisson Distribution Program, CUMPOIS, one of two computer programs that make calculations involving cumulative Poisson distributions. Both programs, CUMPOIS (NPO-17714) and NEWTPOIS (NPO-17715), used independently of one another. CUMPOIS determines cumulative Poisson distribution, used to evaluate cumulative distribution function (cdf) for gamma distributions with integer shape parameters and cdf for X (sup2) distributions with even degrees of freedom. Used by statisticians and others concerned with probabilities of independent events occurring over specific units of time, area, or volume. Written in C.

  2. Cumulative Clearness Index Frequency Distributions on the Territory of the Russian Federation

    Science.gov (United States)

    Frid, S. E.; Lisitskaya, N. V.; Popel, O. S.

    2018-02-01

    Cumulative distributions of clearness index values are constructed for the territory of Russia based on ground observation results and NASA POWER data. The obtained distributions lie close to each other, which means that the NASA POWER data can be used in solar power installations simulation at temperate and high latitudes. Approximation of the obtained distributions is carried out. The values of equation coefficients for the cumulative clearness index distributions constructed for a wide range of climatic conditions are determined. Equations proposed for a tropical climate are used in the calculations, so they can be regarded as universal ones.

  3. Influence of the turbulence typing scheme upon the cumulative frequency distribution of the calculated relative concentrations for different averaging times

    Energy Technology Data Exchange (ETDEWEB)

    Kretzschmar, J.G.; Mertens, I.

    1984-01-01

    Over the period 1977-1979, hourly meteorological measurements at the Nuclear Energy Research Centre, Mol, Belgium and simultaneous synoptic observations at the nearby military airport of Kleine Brogel, have been compiled as input data for a bi-Gaussian dispersion model. The available information has first of all been used to determine hourly stability classes in ten widely used turbulent diffusion typing schemes. Systematic correlations between different systems were rare. Twelve different combinations of diffusion typing scheme-dispersion parameters were then used for calculating cumulative frequency distributions of 1 h, 8 h, 16 h, 3 d, and 26 d average ground-level concentrations at receptors respectively at 500 m, 1 km, 2 km, 4 km and 8 km from continuous ground-level release and an elevated release at 100 m height. Major differences were noted as well in the extreme values, the higher percentiles, as in the annual mean concentrations. These differences are almost entirely due to the differences in the numercial values (as a function of distance) of the various sets of dispersion parameters actually in use for impact assessment studies. Dispersion parameter sets giving the lowest normalized ground-level concentration values for ground level releases give the highest results for elevated releases and vice versa. While it was illustrated once again that the applicability of a given set of dispersion parameters is restricted due to the specific conditions under which the given set derived, it was also concluded that systematic experimental work to validate certain assumptions is urgently needed.

  4. Calculating Cumulative Binomial-Distribution Probabilities

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.

  5. Cumulative processes and quark distribution in nuclei

    International Nuclear Information System (INIS)

    Kondratyuk, L.; Shmatikov, M.

    1984-01-01

    Assuming existence of multiquark (mainly 12q) bags in nuclei the spectra of cumulative nucleons and mesons produced in high-energy particle-nucleus collisions are discussed. The exponential form of quark momentum distribution in 12q-bag (agreeing well with the experimental data on lepton-nucleus interactions at large q 2 ) is shown to result in quasi-exponential distribution of cumulative particles over the light-cone variable αsub(B). The dependence of f(αsub(B); psub(perpendicular)) (where psub(perpendicular) is the transverse momentum of the bag) upon psub(perpendicular) is considered. The yields of cumulative resonances as well as effects related to the u- and d-quark distributions in N > Z nuclei being different are dicscussed

  6. Lyapunov exponent of the random frequency oscillator: cumulant expansion approach

    International Nuclear Information System (INIS)

    Anteneodo, C; Vallejos, R O

    2010-01-01

    We consider a one-dimensional harmonic oscillator with a random frequency, focusing on both the standard and the generalized Lyapunov exponents, λ and λ* respectively. We discuss the numerical difficulties that arise in the numerical calculation of λ* in the case of strong intermittency. When the frequency corresponds to a Ornstein-Uhlenbeck process, we compute analytically λ* by using a cumulant expansion including up to the fourth order. Connections with the problem of finding an analytical estimate for the largest Lyapunov exponent of a many-body system with smooth interactions are discussed.

  7. Exact probability distribution function for the volatility of cumulative production

    Science.gov (United States)

    Zadourian, Rubina; Klümper, Andreas

    2018-04-01

    In this paper we study the volatility and its probability distribution function for the cumulative production based on the experience curve hypothesis. This work presents a generalization of the study of volatility in Lafond et al. (2017), which addressed the effects of normally distributed noise in the production process. Due to its wide applicability in industrial and technological activities we present here the mathematical foundation for an arbitrary distribution function of the process, which we expect will pave the future research on forecasting of the production process.

  8. A spot-matching method using cumulative frequency matrix in 2D gel images

    Science.gov (United States)

    Han, Chan-Myeong; Park, Joon-Ho; Chang, Chu-Seok; Ryoo, Myung-Chun

    2014-01-01

    A new method for spot matching in two-dimensional gel electrophoresis images using a cumulative frequency matrix is proposed. The method improves on the weak points of the previous method called ‘spot matching by topological patterns of neighbour spots’. It accumulates the frequencies of neighbour spot pairs produced through the entire matching process and determines spot pairs one by one in order of higher frequency. Spot matching by frequencies of neighbour spot pairs shows a fairly better performance. However, it can give researchers a hint for whether the matching results can be trustworthy or not, which can save researchers a lot of effort for verification of the results. PMID:26019609

  9. Pulse frequency and soil-litter mixing alter the control of cumulative precipitation over litter decomposition.

    Science.gov (United States)

    Joly, François-Xavier; Kurupas, Kelsey L; Throop, Heather L

    2017-09-01

    Macroclimate has traditionally been considered the predominant driver of litter decomposition. However, in drylands, cumulative monthly or annual precipitation typically fails to predict decomposition. In these systems, the windows of opportunity for decomposer activity may rather depend on the precipitation frequency and local factors affecting litter desiccation, such as soil-litter mixing. We used a full-factorial microcosm experiment to disentangle the relative importance of cumulative precipitation, pulse frequency, and soil-litter mixing on litter decomposition. Decomposition, measured as litter carbon loss, saturated with increasing cumulative precipitation when pulses were large and infrequent, suggesting that litter moisture no longer increased and/or microbial activity was no longer limited by water availability above a certain pulse size. More frequent precipitation pulses led to increased decomposition at high levels of cumulative precipitation. Soil-litter mixing consistently increased decomposition, with greatest relative increase (+194%) under the driest conditions. Collectively, our results highlight the need to consider precipitation at finer temporal scale and incorporate soil-litter mixing as key driver of decomposition in drylands. © 2017 by the Ecological Society of America.

  10. CDF-XL: computing cumulative distribution functions of reaction time data in Excel.

    Science.gov (United States)

    Houghton, George; Grange, James A

    2011-12-01

    In experimental psychology, central tendencies of reaction time (RT) distributions are used to compare different experimental conditions. This emphasis on the central tendency ignores additional information that may be derived from the RT distribution itself. One method for analysing RT distributions is to construct cumulative distribution frequency plots (CDFs; Ratcliff, Psychological Bulletin 86:446-461, 1979). However, this method is difficult to implement in widely available software, severely restricting its use. In this report, we present an Excel-based program, CDF-XL, for constructing and analysing CDFs, with the aim of making such techniques more readily accessible to researchers, including students (CDF-XL can be downloaded free of charge from the Psychonomic Society's online archive). CDF-XL functions as an Excel workbook and starts from the raw experimental data, organised into three columns (Subject, Condition, and RT) on an Input Data worksheet (a point-and-click utility is provided for achieving this format from a broader data set). No further preprocessing or sorting of the data is required. With one click of a button, CDF-XL will generate two forms of cumulative analysis: (1) "standard" CDFs, based on percentiles of participant RT distributions (by condition), and (2) a related analysis employing the participant means of rank-ordered RT bins. Both analyses involve partitioning the data in similar ways, but the first uses a "median"-type measure at the participant level, while the latter uses the mean. The results are presented in three formats: (i) by participants, suitable for entry into further statistical analysis; (ii) grand means by condition; and (iii) completed CDF plots in Excel charts.

  11. Evaluation of a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Imae, Toshikazu; Takenaka, Shigeharu; Saotome, Naoya

    2016-01-01

    The purpose of this study was to evaluate a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy (SBRT) using volumetric modulated arc therapy (VMAT). VMAT is capable of acquiring respiratory signals derived from projection images and machine parameters based on machine logs during VMAT delivery. Dose distributions were reconstructed from the respiratory signals and machine parameters in the condition where respiratory signals were without division, divided into 4 and 10 phases. The dose distribution of each respiratory phase was calculated on the planned four-dimensional CT (4DCT). Summation of the dose distributions was carried out using deformable image registration (DIR), and cumulative dose distributions were compared with those of the corresponding plans. Without division, dose differences between cumulative distribution and plan were not significant. In the condition Where respiratory signals were divided, dose differences were observed over dose in cranial region and under dose in caudal region of planning target volume (PTV). Differences between 4 and 10 phases were not significant. The present method Was feasible for evaluating cumulative dose distribution in VMAT-SBRT using 4DCT and DIR. (author)

  12. Percent relative cumulative frequency analysis in indirect calorimetry: application to studies of transgenic mice.

    Science.gov (United States)

    Riachi, Marc; Himms-Hagen, Jean; Harper, Mary-Ellen

    2004-12-01

    Indirect calorimetry is commonly used in research and clinical settings to assess characteristics of energy expenditure. Respiration chambers in indirect calorimetry allow measurements over long periods of time (e.g., hours to days) and thus the collection of large sets of data. Current methods of data analysis usually involve the extraction of only a selected small proportion of data, most commonly the data that reflects resting metabolic rate. Here, we describe a simple quantitative approach for the analysis of large data sets that is capable of detecting small differences in energy metabolism. We refer to it as the percent relative cumulative frequency (PRCF) approach and have applied it to the study of uncoupling protein-1 (UCP1) deficient and control mice. The approach involves sorting data in ascending order, calculating their cumulative frequency, and expressing the frequencies in the form of percentile curves. Results demonstrate the sensitivity of the PRCF approach for analyses of oxygen consumption (.VO2) as well as respiratory exchange ratio data. Statistical comparisons of PRCF curves are based on the 50th percentile values and curve slopes (H values). The application of the PRCF approach revealed that energy expenditure in UCP1-deficient mice housed and studied at room temperature (24 degrees C) is on average 10% lower (p lower environmental temperature, there were no differences in .VO2 between groups. The latter is likely due to augmented shivering thermogenesis in UCP1-deficient mice compared with controls. With the increased availability of murine models of metabolic disease, indirect calorimetry is increasingly used, and the PRCF approach provides a novel and powerful means for data analysis.

  13. Prediction of a photovoltaic system performance using cumulative frequency curves of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lasnier, F; Sivoththaman, S [Asian Inst. of Technology, Bangkok (TH). Div. of Energy Technology

    1990-01-01

    The system performance of stand-alone photovoltaic systems is analysed. From the hourly radiation data for Bangkok (from 1984 to 1987) the cumulative frequency curves of radiation are generated and a typical meteorological day (TMD) is created each year. The system performance is determined using both the TMD radiation and the actual radiation values. The comparison results show that the TMD method can be applied for the sizing of stand-alone photovoltaic systems. The storage batteries of realistic sizes usually exhibit a daily cyclic variation in state-of-charge, with constant load consumption. Only very large and unrealistic sizes of batteries show a seasonal variation in state-of-charge. This is the fact that prompted the attempt to predict the system performance for a season by using a single representative day (TMD) of that season. Apart from giving reliable results, the TMD method significantly reduces the computation time and simplifies the process. (author).

  14. Study of cumulative fatigue damage detection for used parts with nonlinear output frequency response functions based on NARMAX modelling

    Science.gov (United States)

    Huang, Honglan; Mao, Hanying; Mao, Hanling; Zheng, Weixue; Huang, Zhenfeng; Li, Xinxin; Wang, Xianghong

    2017-12-01

    Cumulative fatigue damage detection for used parts plays a key role in the process of remanufacturing engineering and is related to the service safety of the remanufactured parts. In light of the nonlinear properties of used parts caused by cumulative fatigue damage, the based nonlinear output frequency response functions detection approach offers a breakthrough to solve this key problem. First, a modified PSO-adaptive lasso algorithm is introduced to improve the accuracy of the NARMAX model under impulse hammer excitation, and then, an effective new algorithm is derived to estimate the nonlinear output frequency response functions under rectangular pulse excitation, and a based nonlinear output frequency response functions index is introduced to detect the cumulative fatigue damage in used parts. Then, a novel damage detection approach that integrates the NARMAX model and the rectangular pulse is proposed for nonlinear output frequency response functions identification and cumulative fatigue damage detection of used parts. Finally, experimental studies of fatigued plate specimens and used connecting rod parts are conducted to verify the validity of the novel approach. The obtained results reveal that the new approach can detect cumulative fatigue damages of used parts effectively and efficiently and that the various values of the based nonlinear output frequency response functions index can be used to detect the different fatigue damages or working time. Since the proposed new approach can extract nonlinear properties of systems by only a single excitation of the inspected system, it shows great promise for use in remanufacturing engineering applications.

  15. Rainfall Intensity and Frequency Explain Production Basis Risk in Cumulative Rain Index Insurance

    Science.gov (United States)

    Muneepeerakul, Chitsomanus P.; Muneepeerakul, Rachata; Huffaker, Ray G.

    2017-12-01

    With minimal moral hazard and adverse selection, weather index insurance promises financial resilience to farmers struck by harsh weather conditions through swift compensation at affordable premium. Despite these advantages, the very nature of indexing gives rise to production basis risk as the selected weather indexes do not sufficiently correspond to actual damages. To address this problem, we develop a stochastic yield model, built upon a stochastic soil moisture model driven by marked Poisson rainfall. Our analysis shows that even under similar temperature and rainfall amount yields can differ significantly; this was empirically supported by a 2-year field experiment in which rain-fed maize was grown under very similar total rainfall. Here, the year with more intense, less-frequent rainfall produces a better yield—a rare counter evidence to most climate change projections. Through a stochastic yield model, we demonstrate the crucial roles of rainfall intensity and frequency in determining the yield. Importantly, the model allows us to compute rainfall pattern-related basis risk inherent in cumulative rain index insurance. The model results and a case study herein clearly show that total rainfall is a poor indicator of yield, imposing unnecessary production basis risk on farmers and false-positive payouts on insurers. Incorporating rainfall intensity and frequency in the design of rain index insurance can offer farmers better protection, while maintaining the attractive features of the weather index insurance and thus fulfilling its promise of financial resilience.

  16. A personal radio-frequency dosimeter with cumulative-dose recording capabilities

    International Nuclear Information System (INIS)

    Rochelle, R.W.; Moore, M.R.; Thomas, R.S.; Ewing, P.D.; Hess, R.A.; Hoffheins, B.S.

    1990-01-01

    The radio-frequency (rf) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the rf dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the rf dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer via the dosimeter's serial port. The rf dosimeter should increase knowledge of the levels of electric fields to which individuals are exposed. 13 refs., 16 figs., 2 tabs

  17. Baseline for the cumulants of net-proton distributions at STAR

    International Nuclear Information System (INIS)

    Luo, Xiaofeng; Mohanty, Bedangadas; Xu, Nu

    2014-01-01

    We present a systematic comparison between the recently measured cumulants of the net-proton distributions by STAR for 0–5% central Au + Au collisions at √(s NN )=7.7–200 GeV and two kinds of possible baseline measure, the Poisson and Binomial baselines. These baseline measures are assuming that the proton and anti-proton distributions independently follow Poisson statistics or Binomial statistics. The higher order cumulant net-proton data are observed to deviate from all the baseline measures studied at 19.6 and 27 GeV. We also compare the net-proton with net-baryon fluctuations in UrQMD and AMPT model, and convert the net-proton fluctuations to net-baryon fluctuations in AMPT model by using a set of formula

  18. CDFTBL: A statistical program for generating cumulative distribution functions from data

    International Nuclear Information System (INIS)

    Eslinger, P.W.

    1991-06-01

    This document describes the theory underlying the CDFTBL code and gives details for using the code. The CDFTBL code provides an automated tool for generating a statistical cumulative distribution function that describes a set of field data. The cumulative distribution function is written in the form of a table of probabilities, which can be used in a Monte Carlo computer code. A a specific application, CDFTBL can be used to analyze field data collected for parameters required by the PORMC computer code. Section 2.0 discusses the mathematical basis of the code. Section 3.0 discusses the code structure. Section 4.0 describes the free-format input command language, while Section 5.0 describes in detail the commands to run the program. Section 6.0 provides example program runs, and Section 7.0 provides references. The Appendix provides a program source listing. 11 refs., 2 figs., 19 tabs

  19. On positivity of time-frequency distributions.

    NARCIS (Netherlands)

    Janssen, A.J.E.M.; Claasen, T.A.C.M.

    1985-01-01

    Consideration is given to the problem of how to regard the fundamental impossibility with time-frequency energy distributions of Cohen's class always to be nonnegative and, at the same time, to have correct marginal distributions. It is shown that the Wigner distribution is the only member of a

  20. Estimating the distribution of lifetime cumulative radon exposures for California residents: a brief summary

    International Nuclear Information System (INIS)

    Liu, K.-S.; Chang, Y.-L.; Hayward, S.B.; Gadgil, A.J.; Nero, A.V.

    1992-01-01

    Data on residential radon concentrations in California, together with information on California residents' moving houses and time-activity patterns, have been used to estimate the distribution of lifetime cumulative exposures to 222 Rn. This distribution was constructed using Monte Carlo techniques to simulate the lifetime occupancy histories and associated radon exposures of 10,000 California residents. For standard male and female lifespans, the simulation sampled from transition probability matrices representing changes of residence within and between six regions of California, as well as into and out of the other United States, and then sampled from the appropriate regional (or national) distribution of indoor concentrations. The resulting distribution of lifetime cumulative exposures has a significantly narrower relative width than the distribution of California indoor concentrations, with only a small fraction (less than 0.2%) of the population having lifetime exposures equivalent to living their lifetimes in a single home with a radon concentration of 148 Bq.m -3 or more. (author)

  1. Simulation by the method of inverse cumulative distribution function applied in optimising of foundry plant production

    Directory of Open Access Journals (Sweden)

    J. Szymszal

    2009-01-01

    Full Text Available The study discusses application of computer simulation based on the method of inverse cumulative distribution function. The simulationrefers to an elementary static case, which can also be solved by physical experiment, consisting mainly in observations of foundryproduction in a selected foundry plant. For the simulation and forecasting of foundry production quality in selected cast iron grade, arandom number generator of Excel calculation sheet was chosen. Very wide potentials of this type of simulation when applied to theevaluation of foundry production quality were demonstrated, using a number generator of even distribution for generation of a variable ofan arbitrary distribution, especially of a preset empirical distribution, without any need of adjusting to this variable the smooth theoreticaldistributions.

  2. Global Earthquake Hazard Frequency and Distribution

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Earthquake Hazard Frequency and Distribution is a 2.5 minute grid utilizing Advanced National Seismic System (ANSS) Earthquake Catalog data of actual...

  3. Global Drought Hazard Frequency and Distribution

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Drought Hazard Frequency and Distribution is a 2.5 minute grid based upon the International Research Institute for Climate Prediction's (IRI) Weighted Anomaly...

  4. Gravitational wave chirp search: no-signal cumulative distribution of the maximum likelihood detection statistic

    International Nuclear Information System (INIS)

    Croce, R P; Demma, Th; Longo, M; Marano, S; Matta, V; Pierro, V; Pinto, I M

    2003-01-01

    The cumulative distribution of the supremum of a set (bank) of correlators is investigated in the context of maximum likelihood detection of gravitational wave chirps from coalescing binaries with unknown parameters. Accurate (lower-bound) approximants are introduced based on a suitable generalization of previous results by Mohanty. Asymptotic properties (in the limit where the number of correlators goes to infinity) are highlighted. The validity of numerical simulations made on small-size banks is extended to banks of any size, via a Gaussian correlation inequality

  5. Galactic Subsystems on the Basis of Cumulative Distribution of Space Velocities

    Directory of Open Access Journals (Sweden)

    Vidojević, S.

    2008-12-01

    Full Text Available A sample containing $4,614$ stars with available space velocities and high-quality kinematical data from the Arihip Catalogue is formed. For the purpose of distinguishing galactic subsystems the cumulative distribution of space velocities is studied. The fractions of the three subsystems are found to be: thin disc 92\\%, thick disc 6\\% and halo 2\\%. These results are verified by analysing the elements of velocity ellipsoids and the shape and size of the galactocentric orbits of the sample stars, i.e. the planar and vertical eccentricities of the orbits.

  6. Positivity of time-frequency distribution functions

    NARCIS (Netherlands)

    Janssen, A.J.E.M.

    1988-01-01

    This paper deals with the question how various 'natural' conditions posed on time-frequency distribution functions prevent them to be nonnegative everywhere for all signals. The attention is restricted mainly to distribution functions that involve the signal bilinearly. This paper summarizes and

  7. A method for the calculation of the cumulative failure probability distribution of complex repairable systems

    International Nuclear Information System (INIS)

    Caldarola, L.

    1976-01-01

    A method is proposed for the analytical evaluation of the cumulative failure probability distribution of complex repairable systems. The method is based on a set of integral equations each one referring to a specific minimal cut set of the system. Each integral equation links the unavailability of a minimal cut set to its failure probability density distribution and to the probability that the minimal cut set is down at the time t under the condition that it was down at time t'(t'<=t). The limitations for the applicability of the method are also discussed. It has been concluded that the method is applicable if the process describing the failure of a minimal cut set is a 'delayed semi-regenerative process'. (Auth.)

  8. Cumulative distribution functions associated with bubble-nucleation processes in cavitation

    KAUST Repository

    Watanabe, Hiroshi

    2010-11-15

    Bubble-nucleation processes of a Lennard-Jones liquid are studied by molecular dynamics simulations. Waiting time, which is the lifetime of a superheated liquid, is determined for several system sizes, and the apparent finite-size effect of the nucleation rate is observed. From the cumulative distribution function of the nucleation events, the bubble-nucleation process is found to be not a simple Poisson process but a Poisson process with an additional relaxation time. The parameters of the exponential distribution associated with the process are determined by taking the relaxation time into account, and the apparent finite-size effect is removed. These results imply that the use of the arithmetic mean of the waiting time until a bubble grows to the critical size leads to an incorrect estimation of the nucleation rate. © 2010 The American Physical Society.

  9. An uncertainty importance measure using a distance metric for the change in a cumulative distribution function

    International Nuclear Information System (INIS)

    Chun, Moon-Hyun; Han, Seok-Jung; Tak, Nam-IL

    2000-01-01

    A simple measure of uncertainty importance using the entire change of cumulative distribution functions (CDFs) has been developed for use in probability safety assessments (PSAs). The entire change of CDFs is quantified in terms of the metric distance between two CDFs. The metric distance measure developed in this study reflects the relative impact of distributional changes of inputs on the change of an output distribution, while most of the existing uncertainty importance measures reflect the magnitude of relative contribution of input uncertainties to the output uncertainty. The present measure has been evaluated analytically for various analytical distributions to examine its characteristics. To illustrate the applicability and strength of the present measure, two examples are provided. The first example is an application of the present measure to a typical problem of a system fault tree analysis and the second one is for a hypothetical non-linear model. Comparisons of the present result with those obtained by existing uncertainty importance measures show that the metric distance measure is a useful tool to express the measure of uncertainty importance in terms of the relative impact of distributional changes of inputs on the change of an output distribution

  10. Relationship between mutation frequency of GPA locus and cumulative dose among medical diagnostic X-ray workers

    International Nuclear Information System (INIS)

    Wang Jixian; Yu Wenru; Li Benxiao; Fan Tiqiang; Li Zhen; Gao Zhiwei; Chen Zhenjun; Zhao Yongcheng

    2000-01-01

    Objective: To explore the feasibility of using GPA locus mutation assay as a bio-dosimeter for occupational exposure to ionizing radiation. Methods: An improved technique of GPA locus mutation assay was used in th study. The frequencies of mutant RBC in peripheral blood of 55 medical X-ray workers and 50 controls employed in different calendar-year periods were detected. The relationship between mutation frequencies (MFs) and period of entry, working years and cumulative doses were analyzed. Results: The MFs were significantly elevated among X-ray workers employed before 1970. This finding is similar to the result of cancer epidemiological study among medical X-ray workers , in which the cancer risk was significantly increased only X-ray workers employed before 1970. The MFs of GPA increased with increasing cumulative dose. The dose-effect relationship of Nφ MF with cumulative dose was closer than that of NN MF. Conclusion: There are many problems to be solved for using GPA MF assay as a bio-dosimeter such as individual variation, specificity and calibration curve of dose-effect relationship

  11. Cumulative history recorded in the depth distribution of radiocesium in sediments deposited on a sandbar

    International Nuclear Information System (INIS)

    Tanaka, Kazuya; Kondo, Hiroaki; Sakaguchi, Aya; Takahashi, Yoshio

    2015-01-01

    We collected sediments deposited on a sandbar from the surface to 20 cm in depth in the Abukuma River to clarify the history of radiocesium derived from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. We analyzed the "1"3"7Cs concentration in the sediments from size-fractioned samples as well as bulk samples. The depth distribution of "1"3"7Cs showed the highest concentration in the deepest sediment layer (18–20 cm) studied, which indicates that sediments with a lower "1"3"7Cs concentration were transported and deposited on sediments having a higher "1"3"7Cs concentration. At the same time, the depth distribution suggests a decrease in radioactivity in provenance areas of the sediments. Analysis of the size-fractioned sediments indicated that the three sediment layers at 4–6 cm, 16–18 cm and 18–20 cm intervals had similar size distribution of "1"3"7Cs and grain size composition although the concentration levels of "1"3"7Cs were different according to their bulk concentrations. The size distribution of "1"3"7Cs also supported the possibility that the decrease in "1"3"7Cs concentration in bulk sediments above 18 cm is due to a decrease in the level of radioactivity in the catchment area. A comparison of the size distribution of "1"3"7Cs between the sediment layers above and below 18 cm suggested that the "1"3"7Cs concentration in the transported fine sediment particles decreased more with time than the "1"3"7Cs concentration in the coarse particles, reflecting the selective transport of the finer particles. The results of this study demonstrated that sediment layers deposited on a sandbar retained the cumulative history of the fluvial transport of radiocesium after the FDNPP accident. - Highlights: • We investigated the history of "1"3"7Cs recorded in sediments in the Abukuma River. • "1"3"7Cs concentration was the highest in the deepest sediment layer studied. • The depth distribution suggests a decrease in radioactivity in

  12. Probability, conditional probability and complementary cumulative distribution functions in performance assessment for radioactive waste disposal

    International Nuclear Information System (INIS)

    Helton, J.C.

    1996-03-01

    A formal description of the structure of several recent performance assessments (PAs) for the Waste Isolation Pilot Plant (WIPP) is given in terms of the following three components: a probability space (S st , S st , p st ) for stochastic uncertainty, a probability space (S su , S su , p su ) for subjective uncertainty and a function (i.e., a random variable) defined on the product space associated with (S st , S st , p st ) and (S su , S su , p su ). The explicit recognition of the existence of these three components allows a careful description of the use of probability, conditional probability and complementary cumulative distribution functions within the WIPP PA. This usage is illustrated in the context of the U.S. Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, Subpart B). The paradigm described in this presentation can also be used to impose a logically consistent structure on PAs for other complex systems

  13. Probability, conditional probability and complementary cumulative distribution functions in performance assessment for radioactive waste disposal

    International Nuclear Information System (INIS)

    Helton, J.C.

    1996-01-01

    A formal description of the structure of several recent performance assessments (PAs) for the Waste Isolation Pilot Plant (WIPP) is given in terms of the following three components: a probability space (S st , L st , P st ) for stochastic uncertainty, a probability space (S su , L su , P su ) for subjective uncertainty and a function (i.e., a random variable) defined on the product space associated with (S st , L st , P st ) and (S su , L su , P su ). The explicit recognition of the existence of these three components allows a careful description of the use of probability, conditional probability and complementary cumulative distribution functions within the WIPP PA. This usage is illustrated in the context of the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, Subpart B). The paradigm described in this presentation can also be used to impose a logically consistent structure on PAs for other complex systems

  14. Morphology of the cumulative logistic distribution when used as a model of radiologic film characteristic curves

    International Nuclear Information System (INIS)

    Prince, J.R.

    1988-01-01

    The cumulative logistic distribution (CLD) is an empiric model for film characteristic curves. Characterizing the shape parameters of the CLD in terms of contrast, latitude and speed is required. The CLD is written as Υ-F=D/[1+EXP-(Κ+κ 1 X)] where Υ is the optical density (OD) at log exposure X, F is fog level, D is a constant equal to Dm-F, Κ and κ 1 are shape parameters, and Dm is the maximum attainable OD. Further analysis demonstrates that when Κ is held constant, Κ 1 characterizes contrast (the larger κ 1 , the greater the contrast) and hence latitude; when κ 1 is held constant, Κ characterizes film speed (the larger Κ is, the faster the film). These equations and concepts are further illustrated with examples from radioscintigraphy, diagnostic radiology, and light sensitometry

  15. Probabilistic performance estimators for computational chemistry methods: The empirical cumulative distribution function of absolute errors

    Science.gov (United States)

    Pernot, Pascal; Savin, Andreas

    2018-06-01

    Benchmarking studies in computational chemistry use reference datasets to assess the accuracy of a method through error statistics. The commonly used error statistics, such as the mean signed and mean unsigned errors, do not inform end-users on the expected amplitude of prediction errors attached to these methods. We show that, the distributions of model errors being neither normal nor zero-centered, these error statistics cannot be used to infer prediction error probabilities. To overcome this limitation, we advocate for the use of more informative statistics, based on the empirical cumulative distribution function of unsigned errors, namely, (1) the probability for a new calculation to have an absolute error below a chosen threshold and (2) the maximal amplitude of errors one can expect with a chosen high confidence level. Those statistics are also shown to be well suited for benchmarking and ranking studies. Moreover, the standard error on all benchmarking statistics depends on the size of the reference dataset. Systematic publication of these standard errors would be very helpful to assess the statistical reliability of benchmarking conclusions.

  16. Probability, conditional probability and complementary cumulative distribution functions in performance assessment for radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Helton, J.C. [Arizona State Univ., Tempe, AZ (United States)

    1996-03-01

    A formal description of the structure of several recent performance assessments (PAs) for the Waste Isolation Pilot Plant (WIPP) is given in terms of the following three components: a probability space (S{sub st}, S{sub st}, p{sub st}) for stochastic uncertainty, a probability space (S{sub su}, S{sub su}, p{sub su}) for subjective uncertainty and a function (i.e., a random variable) defined on the product space associated with (S{sub st}, S{sub st}, p{sub st}) and (S{sub su}, S{sub su}, p{sub su}). The explicit recognition of the existence of these three components allows a careful description of the use of probability, conditional probability and complementary cumulative distribution functions within the WIPP PA. This usage is illustrated in the context of the U.S. Environmental Protection Agency`s standard for the geologic disposal of radioactive waste (40 CFR 191, Subpart B). The paradigm described in this presentation can also be used to impose a logically consistent structure on PAs for other complex systems.

  17. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl

    OpenAIRE

    Lehmann, Philipp; Boraty?ski, Zbyszek; Mappes, Tapio; Mousseau, Timothy A.; M?ller, Anders P.

    2016-01-01

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glare...

  18. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

    Science.gov (United States)

    Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

    2016-01-27

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

  19. Benchmarking PARTISN with Analog Monte Carlo: Moments of the Neutron Number and the Cumulative Fission Number Probability Distributions

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, Patrick Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-27

    The purpose of this report is to provide the reader with an understanding of how a Monte Carlo neutron transport code was written, developed, and evolved to calculate the probability distribution functions (PDFs) and their moments for the neutron number at a final time as well as the cumulative fission number, along with introducing several basic Monte Carlo concepts.

  20. Inverter design for high frequency power distribution

    Science.gov (United States)

    King, R. J.

    1985-01-01

    A class of simple resonantly commutated inverters are investigated for use in a high power (100 KW - 1000 KW) high frequency (10 KHz - 20 KHz) AC power distribution system. The Mapham inverter is found to provide a unique combination of large thyristor turn-off angle and good utilization factor, much better than an alternate 'current-fed' inverter. The effects of loading the Mapham inverter entirely with rectifier loads are investigated by simulation and with an experimental 3 KW 20 KHz inverter. This inverter is found to be well suited to a power system with heavy rectifier loading.

  1. Recurrence and frequency of disturbance have cumulative effect on methanotrophic activity, abundance, and community structure.

    Directory of Open Access Journals (Sweden)

    Adrian eHo

    2016-01-01

    Full Text Available Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical disturbances induced as a single event, their resilience to recurring disturbances is less known. Here, using a rice field soil in a microcosm study, we determined whether recurrence and frequency of desiccation-rewetting impose an accumulating effect on the methanotrophic activity. The response of key aerobic methanotroph subgroups (type Ia, Ib, and II were monitored using qPCR assays, and was supported by a t-RFLP analysis. The methanotrophic activity was resilient to recurring desiccation-rewetting, but increasing the frequency of the disturbance by two-fold significantly decreased methane uptake rate. Both the qPCR and t-RFLP analyses were congruent, showing the dominance of type Ia/Ib methanotrophs prior to disturbance, and after disturbance, the recovering community was predominantly comprised of type Ia (Methylobacter methanotrophs. Both type Ib and type II (Methylosinus/Methylocystis methanotrophs were adversely affected by the disturbance, but type II methanotrophs showed recovery over time, indicating relatively higher resilience to the disturbance. This revealed distinct, yet unrecognized traits among the methanotroph community members. Our results show that recurring desiccation-rewetting before a recovery in community abundance had an accumulated effect, compromising methanotrophic activity. While methanotrophs may recover well following sporadic disturbances, their resilience may reach a ‘tipping point’ where activity no longer recovered if disturbance persists and increase in frequency.

  2. Asymptotic Time Averages and Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Muhammad El-Taha

    2016-01-01

    Full Text Available Consider an arbitrary nonnegative deterministic process (in a stochastic setting {X(t,  t≥0} is a fixed realization, i.e., sample-path of the underlying stochastic process with state space S=(-∞,∞. Using a sample-path approach, we give necessary and sufficient conditions for the long-run time average of a measurable function of process to be equal to the expectation taken with respect to the same measurable function of its long-run frequency distribution. The results are further extended to allow unrestricted parameter (time space. Examples are provided to show that our condition is not superfluous and that it is weaker than uniform integrability. The case of discrete-time processes is also considered. The relationship to previously known sufficient conditions, usually given in stochastic settings, will also be discussed. Our approach is applied to regenerative processes and an extension of a well-known result is given. For researchers interested in sample-path analysis, our results will give them the choice to work with the time average of a process or its frequency distribution function and go back and forth between the two under a mild condition.

  3. A comparison of a novel time-based summary measure of dairy cow health against cumulative disease frequency.

    Science.gov (United States)

    McConnel, Craig S; McNeil, Ashleigh A; Hadrich, Joleen C; Lombard, Jason E; Heller, Jane; Garry, Franklyn B

    2018-01-01

    There is an increasing push for dairy production to be scientifically grounded and ethically responsible in the oversight of animal health and well-being. Addressing underlying challenges affecting the quality and length of productive life necessitates novel assessment and accountability metrics. Human medical epidemiologists developed the Disability-Adjusted Life Year metric as a summary measure of health addressing the complementary nature of disease and death. The goal of this project was to develop and implement a dairy Disease-Adjusted Lactation (DALact) summary measure of health, as a comparison against cumulative disease frequency. A total of 5694 cows were enrolled at freshening from January 1st, 2014 through May 26th, 2015 on 3 similarly managed U.S. Midwestern Plains' region dairies. Eleven health categories of interest were tracked from enrollment until culling, death, or the study's completion date. The DALact accounted for the days of life lost due to illness, forced removal, and death relative to the average lactation length across the participating farms. The DALact consistently identified mastitis as the primary disease of concern on all 3 dairies (19,007-23,955 days lost). Secondary issues included musculoskeletal injuries (19,559 days), pneumonia (11,034 days), or lameness (8858 days). By comparison, cumulative frequency measures pointed to mastitis (31-50%) and lameness (25-54%) as the 2 most frequent diseases. Notably, the DALact provided a robust accounting of health events such as musculoskeletal injuries (5010-19,559 days) and calving trauma (2952-5868 days) otherwise overlooked by frequency measures (0-3%). The DALact provides a time-based method for assessing the overall burden of disease on dairies. It is important to emphasize that a summary measure of dairy health goes beyond simply linking morbidity to culling and mortality in a standardized fashion. A summary measure speaks to the burden of disease on both the well-being and

  4. Differences in Crossover Frequency and Distribution among Three Sibling Species of Drosophila

    OpenAIRE

    True, J. R.; Mercer, J. M.; Laurie, C. C.

    1996-01-01

    Comparisons of the genetic and cytogenetic maps of three sibling species of Drosophila reveal marked differences in the frequency and cumulative distribution of crossovers during meiosis. The maps for two of these species, Drosophila melanogaster and D. simulans, have previously been described, while this report presents new map data for D. mauritiana, obtained using a set of P element markers. A genetic map covering nearly the entire genome was constructed by estimating the recombination fra...

  5. GammaCHI: a package for the inversion and computation of the gamma and chi-square cumulative distribution functions (central and noncentral)

    NARCIS (Netherlands)

    A. Gil (Amparo); J. Segura (Javier); N.M. Temme (Nico)

    2015-01-01

    textabstractA Fortran 90 module GammaCHI for computing and inverting the gamma and chi-square cumulative distribution functions (central and noncentral) is presented. The main novelty of this package is the reliable and accurate inversion routines for the noncentral cumulative distribution

  6. Using the cumulative sum algorithm against distributed denial of service attacks in Internet of Things

    CSIR Research Space (South Africa)

    Machaka, Pheeha

    2015-11-01

    Full Text Available The paper presents the threats that are present in Internet of Things (IoT) systems and how they can be used to perpetuate a large scale DDoS attack. The paper investigates how the Cumulative Sum (CUSUM) algorithm can be used to detect a DDoS attack...

  7. Stability of the laws for the distribution of the cumulative failures in railway transport

    OpenAIRE

    Kirill VOYNOV

    2008-01-01

    There are very many different laws of distribution (for example), bellshaped (Gaussian) distribution, lognormal, Weibull distribution, exponential, uniform, Poisson’s, Student’s distributions and so on, which help to describe the real picture of failures with elements in various mechanical systems, in locomotives and carriages, too. To diminish the possibility of getting the rough error in the output of maths data treatment the new method is demonstrated in this article. The task is solved bo...

  8. A comparison of alternative methods of calculating complementary cumulative distribution functions of health effects following an atmospheric radioactive release

    International Nuclear Information System (INIS)

    Ponting, A.C.; Nair, S.

    1984-04-01

    A concept extensively used in studying the consequences of accidental atmospheric radioactive releases is that of the Complementary Cumulative Distribution Function, CCDF. Various methods of calculating CCDFs have been developed with particular applications in putting degraded core accidents in perspective and in identifying release sequences leading to high risks. This note compares three methods with specific reference to their accuracy and computational efficiency. For two of the methods (that used in the US Reactor Safety Study code CRAC2 and extended version of that method), the effects of varying the sector width and considering site-specific population distributions have been determined. For the third method it is only necessary to consider the effects of site-specific population distributions. (author)

  9. Stability of the laws for the distribution of the cumulative failures in railway transport

    Directory of Open Access Journals (Sweden)

    Kirill VOYNOV

    2008-01-01

    Full Text Available There are very many different laws of distribution (for example, bellshaped (Gaussian distribution, lognormal, Weibull distribution, exponential, uniform, Poisson’s, Student’s distributions and so on, which help to describe the real picture of failures with elements in various mechanical systems, in locomotives and carriages, too. To diminish the possibility of getting the rough error in the output of maths data treatment the new method is demonstrated in this article. The task is solved both to the discrete, and to the continuous distributions.

  10. Comparative frequency and allelic distribution of ABO and Rh (D ...

    African Journals Online (AJOL)

    Background: Allelic distribution of major blood groups (ABO and rhesus) has not been defined in Bangladeshi population. Determinants of blood group frequency in this region have not been studied properly. Aim: To determine ABO and rhesus blood group frequency and allelic distribution in a multiethnic area of ...

  11. Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: a moderating role for cumulative risk.

    Science.gov (United States)

    MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

    2014-12-01

    This study used the Fragile Families and Child Well-Being Study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2,768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. Copyright © 2014. Published by Elsevier Ltd.

  12. Rational Arithmetic Mathematica Functions to Evaluate the Two-Sided One Sample K-S Cumulative Sampling Distribution

    Directory of Open Access Journals (Sweden)

    J. Randall Brown

    2007-06-01

    Full Text Available One of the most widely used goodness-of-fit tests is the two-sided one sample Kolmogorov-Smirnov (K-S test which has been implemented by many computer statistical software packages. To calculate a two-sided p value (evaluate the cumulative sampling distribution, these packages use various methods including recursion formulae, limiting distributions, and approximations of unknown accuracy developed over thirty years ago. Based on an extensive literature search for the two-sided one sample K-S test, this paper identifies an exact formula for sample sizes up to 31, six recursion formulae, and one matrix formula that can be used to calculate a p value. To ensure accurate calculation by avoiding catastrophic cancelation and eliminating rounding error, each of these formulae is implemented in rational arithmetic. For the six recursion formulae and the matrix formula, computational experience for sample sizes up to 500 shows that computational times are increasing functions of both the sample size and the number of digits in the numerator and denominator integers of the rational number test statistic. The computational times of the seven formulae vary immensely but the Durbin recursion formula is almost always the fastest. Linear search is used to calculate the inverse of the cumulative sampling distribution (find the confidence interval half-width and tables of calculated half-widths are presented for sample sizes up to 500. Using calculated half-widths as input, computational times for the fastest formula, the Durbin recursion formula, are given for sample sizes up to two thousand.

  13. Cumulative distribution functions associated with bubble-nucleation processes in cavitation

    KAUST Repository

    Watanabe, Hiroshi; Suzuki, Masaru; Ito, Nobuyasu

    2010-01-01

    of the exponential distribution associated with the process are determined by taking the relaxation time into account, and the apparent finite-size effect is removed. These results imply that the use of the arithmetic mean of the waiting time until a bubble grows

  14. Determination of 114Pd cumulative yield and investigation of the fine-structure at light peak in mass distribution of 252Cf spontaneous fission

    International Nuclear Information System (INIS)

    Yu Runlan; Li Xueliang; Cui Anzhi; Guo Jingru; Yan Shuhen; Tang Peijia; Liu Daming

    1991-07-01

    A rapid radiochemical procedure for Pd separation was developed. It was the first time to use radiochemical techniques to determine 114 Pd cumulative yield (2.50 ± 0.14)% in 252 Cf spontaneous fission. The cumulative yields of (3.50 ± 0.13)% and (3.70 ± 0.11)% for 112 Pd and 113g Ag were also obtained. These are in agreement with Skovorodkin's results. The cumulative yields determined show that there is a fine-structure at light peak of mass number A = 113 in the mass distribution of 252 Cf spontaneous fission

  15. Forecasting the Stock Market with Linguistic Rules Generated from the Minimize Entropy Principle and the Cumulative Probability Distribution Approaches

    Directory of Open Access Journals (Sweden)

    Chung-Ho Su

    2010-12-01

    Full Text Available To forecast a complex and non-linear system, such as a stock market, advanced artificial intelligence algorithms, like neural networks (NNs and genetic algorithms (GAs have been proposed as new approaches. However, for the average stock investor, two major disadvantages are argued against these advanced algorithms: (1 the rules generated by NNs and GAs are difficult to apply in investment decisions; and (2 the time complexity of the algorithms to produce forecasting outcomes is very high. Therefore, to provide understandable rules for investors and to reduce the time complexity of forecasting algorithms, this paper proposes a novel model for the forecasting process, which combines two granulating methods (the minimize entropy principle approach and the cumulative probability distribution approach and a rough set algorithm. The model verification demonstrates that the proposed model surpasses the three listed conventional fuzzy time-series models and a multiple regression model (MLR in forecast accuracy.

  16. The frequency characteristics of medium voltage distribution system impedances

    Directory of Open Access Journals (Sweden)

    Liviu Emil Petrean

    2009-10-01

    Full Text Available In this paper we present the frequency characteristics of impedances involved in the electrical equivalent circuit of a large medium voltage distribution system. These impedances influence harmonics distortions propagation occurring due to the nonsinusoidal loads. We analyse the case of a 10 kV large urban distribution system which supplies industrial, commercial and residential customers. The influence of various parameters of the distribution network on the frequency characteristics are presented, in order to assess the interaction of harmonic distortion and distribution system network.

  17. statistical tests for frequency distribution of mean gravity anomalies

    African Journals Online (AJOL)

    ES Obe

    1980-03-01

    Mar 1, 1980 ... STATISTICAL TESTS FOR FREQUENCY DISTRIBUTION OF MEAN. GRAVITY ANOMALIES. By ... approach. Kaula [1,2] discussed the method of applying statistical techniques in the ..... mathematical foundation of physical ...

  18. A Case Series of the Probability Density and Cumulative Distribution of Laryngeal Disease in a Tertiary Care Voice Center.

    Science.gov (United States)

    de la Fuente, Jaime; Garrett, C Gaelyn; Ossoff, Robert; Vinson, Kim; Francis, David O; Gelbard, Alexander

    2017-11-01

    To examine the distribution of clinic and operative pathology in a tertiary care laryngology practice. Probability density and cumulative distribution analyses (Pareto analysis) was used to rank order laryngeal conditions seen in an outpatient tertiary care laryngology practice and those requiring surgical intervention during a 3-year period. Among 3783 new clinic consultations and 1380 operative procedures, voice disorders were the most common primary diagnostic category seen in clinic (n = 3223), followed by airway (n = 374) and swallowing (n = 186) disorders. Within the voice strata, the most common primary ICD-9 code used was dysphonia (41%), followed by unilateral vocal fold paralysis (UVFP) (9%) and cough (7%). Among new voice patients, 45% were found to have a structural abnormality. The most common surgical indications were laryngotracheal stenosis (37%), followed by recurrent respiratory papillomatosis (18%) and UVFP (17%). Nearly 55% of patients presenting to a tertiary referral laryngology practice did not have an identifiable structural abnormality in the larynx on direct or indirect examination. The distribution of ICD-9 codes requiring surgical intervention was disparate from that seen in clinic. Application of the Pareto principle may improve resource allocation in laryngology, but these initial results require confirmation across multiple institutions.

  19. Cumulative incidence, distribution, and determinants of catastrophic health expenditure in Nepal: results from the living standards survey.

    Science.gov (United States)

    Ghimire, Mamata; Ayer, Rakesh; Kondo, Masahide

    2018-02-14

    Nepal has committed to the global community to achieve universal health coverage by 2030. Nevertheless, Nepal still has a high proportion of out-of-pocket health payment and a limited risk-pooling mechanism. Out-of-pocket payment for the healthcare services could result in catastrophic health expenditure (CHE). Evidence is required to effectively channel the efforts to lower those expenses in order to achieve universal health coverage. However, little is known about CHE and its determinants in a broad national context in Nepal. Therefore, this study was conducted to explore the cumulative incidence, distribution, and determinants of CHE in Nepal. Data were obtained from the nationally representative survey, the Nepal Living Standards Survey-third undertaken in 2010/11. Information from 5988 households was used for the analyses. Households were classified as having CHE when their out-of-pocket health payment was greater than or equal to 40% of their capacity to pay. Remaining households were classified as not having CHE. Logistic regression analyses were used to identify determinants of CHE. Based on household-weighted sample, the cumulative incidence of CHE was 10.3% per month in Nepal. This incidence was concentrated in the far-western region and households in the poorer expenditure quartiles. Multivariable logistic regression revealed that households were more likely to face CHE if they; consisted of chronically ill member(s), have a higher burden of acute illness and injuries, have elderly (≥60 years) member(s), belonged to the poor expenditure quartile, and were located in the far-western region. In contrast, households were less likely to incur CHE when their household head was educated. Having children (≤5 years) in households did not significantly affect catastrophic health expenditure. This study identified a high cumulative incidence of CHE. CHE was disproportionately concentrated in the poor households and households located in the far

  20. Cumulative effects of climate and landscape change drive spatial distribution of Rocky Mountain wolverine (Gulo gulo L.).

    Science.gov (United States)

    Heim, Nicole; Fisher, Jason T; Clevenger, Anthony; Paczkowski, John; Volpe, John

    2017-11-01

    Contemporary landscapes are subject to a multitude of human-derived stressors. Effects of such stressors are increasingly realized by population declines and large-scale extirpation of taxa worldwide. Most notably, cumulative effects of climate and landscape change can limit species' local adaptation and dispersal capabilities, thereby reducing realized niche space and range extent. Resolving the cumulative effects of multiple stressors on species persistence is a pressing challenge in ecology, especially for declining species. For example, wolverines ( Gulo gulo L.) persist on only 40% of their historic North American range. While climate change has been shown to be a mechanism of range retractions, anthropogenic landscape disturbance has been recently implicated. We hypothesized these two interact to effect declines. We surveyed wolverine occurrence using camera trapping and genetic tagging at 104 sites at the wolverine range edge, spanning a 15,000 km 2 gradient of climate, topographic, anthropogenic, and biotic variables. We used occupancy and generalized linear models to disentangle the factors explaining wolverine distribution. Persistent spring snow pack-expected to decrease with climate change-was a significant predictor, but so was anthropogenic landscape change. Canid mesocarnivores, which we hypothesize are competitors supported by anthropogenic landscape change, had comparatively weaker effect. Wolverine population declines and range shifts likely result from climate change and landscape change operating in tandem. We contend that similar results are likely for many species and that research that simultaneously examines climate change, landscape change, and the biotic landscape is warranted. Ecology research and species conservation plans that address these interactions are more likely to meet their objectives.

  1. Recurrent frequency-size distribution of characteristic events

    Directory of Open Access Journals (Sweden)

    S. G. Abaimov

    2009-04-01

    Full Text Available Statistical frequency-size (frequency-magnitude properties of earthquake occurrence play an important role in seismic hazard assessments. The behavior of earthquakes is represented by two different statistics: interoccurrent behavior in a region and recurrent behavior at a given point on a fault (or at a given fault. The interoccurrent frequency-size behavior has been investigated by many authors and generally obeys the power-law Gutenberg-Richter distribution to a good approximation. It is expected that the recurrent frequency-size behavior should obey different statistics. However, this problem has received little attention because historic earthquake sequences do not contain enough events to reconstruct the necessary statistics. To overcome this lack of data, this paper investigates the recurrent frequency-size behavior for several problems. First, the sequences of creep events on a creeping section of the San Andreas fault are investigated. The applicability of the Brownian passage-time, lognormal, and Weibull distributions to the recurrent frequency-size statistics of slip events is tested and the Weibull distribution is found to be the best-fit distribution. To verify this result the behaviors of numerical slider-block and sand-pile models are investigated and the Weibull distribution is confirmed as the applicable distribution for these models as well. Exponents β of the best-fit Weibull distributions for the observed creep event sequences and for the slider-block model are found to have similar values ranging from 1.6 to 2.2 with the corresponding aperiodicities CV of the applied distribution ranging from 0.47 to 0.64. We also note similarities between recurrent time-interval statistics and recurrent frequency-size statistics.

  2. Word frequencies: A comparison of Pareto type distributions

    Science.gov (United States)

    Wiegand, Martin; Nadarajah, Saralees; Si, Yuancheng

    2018-03-01

    Mehri and Jamaati (2017) [18] used Zipf's law to model word frequencies in Holy Bible translations for one hundred live languages. We compare the fit of Zipf's law to a number of Pareto type distributions. The latter distributions are shown to provide the best fit, as judged by a number of comparative plots and error measures. The fit of Zipf's law appears generally poor.

  3. Fast Grid Frequency Support from Distributed Inverter-Based Resources

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Anderson F [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-05-04

    This presentation summarizes power hardware-in-the-loop testing performed to evaluate the ability of distributed inverter-coupled generation to support grid frequency on the fastest time scales. The research found that distributed PV inverters and other DERs can effectively support the grid on sub-second time scales.

  4. Reduction of CMIP5 models bias using Cumulative Distribution Function transform and impact on crops yields simulations across West Africa.

    Science.gov (United States)

    Moise Famien, Adjoua; Defrance, Dimitri; Sultan, Benjamin; Janicot, Serge; Vrac, Mathieu

    2017-04-01

    Different CMIP exercises show that the simulations of the future/current temperature and precipitation are complex with a high uncertainty degree. For example, the African monsoon system is not correctly simulated and most of the CMIP5 models underestimate the precipitation. Therefore, Global Climate Models (GCMs) show significant systematic biases that require bias correction before it can be used in impacts studies. Several methods of bias corrections have been developed for several years and are increasingly using more complex statistical methods. The aims of this work is to show the interest of the CDFt (Cumulative Distribution Function transfom (Michelangeli et al.,2009)) method to reduce the data bias from 29 CMIP5 GCMs over Africa and to assess the impact of bias corrected data on crop yields prediction by the end of the 21st century. In this work, we apply the CDFt to daily data covering the period from 1950 to 2099 (Historical and RCP8.5) and we correct the climate variables (temperature, precipitation, solar radiation, wind) by the use of the new daily database from the EU project WATer and global CHange (WATCH) available from 1979 to 2013 as reference data. The performance of the method is assessed in several cases. First, data are corrected based on different calibrations periods and are compared, on one hand, with observations to estimate the sensitivity of the method to the calibration period and, on other hand, with another bias-correction method used in the ISIMIP project. We find that, whatever the calibration period used, CDFt corrects well the mean state of variables and preserves their trend, as well as daily rainfall occurrence and intensity distributions. However, some differences appear when compared to the outputs obtained with the method used in ISIMIP and show that the quality of the correction is strongly related to the reference data. Secondly, we validate the bias correction method with the agronomic simulations (SARRA-H model (Kouressy

  5. Application of approximations for joint cumulative k-distributions for mixtures to FSK radiation heat transfer in multi-component high temperature non-LTE plasmas

    International Nuclear Information System (INIS)

    Maurente, André; França, Francis H.R.; Miki, Kenji; Howell, John R.

    2012-01-01

    Approximations for joint cumulative k-distribution for mixtures are efficient for full spectrum k-distribution (FSK) computations. These approximations provide reduction of the database that is necessary to perform FSK computation when compared to the direct approach, which uses cumulative k-distributions computed from the spectrum of the mixture, and also less computational expensive when compared to techniques in which RTE's are required to be solved for each component of the mixture. The aim of the present paper is to extend the approximations for joint cumulative k-distributions for non-LTE media. For doing that, a FSK to non-LTE media formulation well-suited to be applied along with approximations for joint cumulative k-distributions is presented. The application of the proposed methodology is demonstrated by solving the radiation heat transfer in non-LTE high temperature plasmas composed of N, O, N 2 , NO, N 2 + and mixtures of these species. The two more efficient approximations, that is, the superposition and multiplication are employed and analyzed.

  6. Estimation of modal parameters using bilinear joint time frequency distributions

    Science.gov (United States)

    Roshan-Ghias, A.; Shamsollahi, M. B.; Mobed, M.; Behzad, M.

    2007-07-01

    In this paper, a new method is proposed for modal parameter estimation using time-frequency representations. Smoothed Pseudo Wigner-Ville distribution which is a member of the Cohen's class distributions is used to decouple vibration modes completely in order to study each mode separately. This distribution reduces cross-terms which are troublesome in Wigner-Ville distribution and retains the resolution as well. The method was applied to highly damped systems, and results were superior to those obtained via other conventional methods.

  7. Correcting length-frequency distributions for imperfect detection

    Science.gov (United States)

    Breton, André R.; Hawkins, John A.; Winkelman, Dana L.

    2013-01-01

    Sampling gear selects for specific sizes of fish, which may bias length-frequency distributions that are commonly used to assess population size structure, recruitment patterns, growth, and survival. To properly correct for sampling biases caused by gear and other sources, length-frequency distributions need to be corrected for imperfect detection. We describe a method for adjusting length-frequency distributions when capture and recapture probabilities are a function of fish length, temporal variation, and capture history. The method is applied to a study involving the removal of Smallmouth Bass Micropterus dolomieu by boat electrofishing from a 38.6-km reach on the Yampa River, Colorado. Smallmouth Bass longer than 100 mm were marked and released alive from 2005 to 2010 on one or more electrofishing passes and removed on all other passes from the population. Using the Huggins mark–recapture model, we detected a significant effect of fish total length, previous capture history (behavior), year, pass, year×behavior, and year×pass on capture and recapture probabilities. We demonstrate how to partition the Huggins estimate of abundance into length frequencies to correct for these effects. Uncorrected length frequencies of fish removed from Little Yampa Canyon were negatively biased in every year by as much as 88% relative to mark–recapture estimates for the smallest length-class in our analysis (100–110 mm). Bias declined but remained high even for adult length-classes (≥200 mm). The pattern of bias across length-classes was variable across years. The percentage of unadjusted counts that were below the lower 95% confidence interval from our adjusted length-frequency estimates were 95, 89, 84, 78, 81, and 92% from 2005 to 2010, respectively. Length-frequency distributions are widely used in fisheries science and management. Our simple method for correcting length-frequency estimates for imperfect detection could be widely applied when mark–recapture data

  8. Development of optical fiber frequency and time distribution systems

    Science.gov (United States)

    Lutes, G.

    1982-01-01

    The development of ultra stable optical fiber distribution systems for the dissemination of frequency and timing references is reported. The ultimate design goals for these systems are a frequency stability of 10 to the -17 power for tau or = 100 sec and time stability of + or - 0.1 ns for 1 year and operation over distances or = 30 km. A prototype system is reviewed and progress is discussed.

  9. Detecting mammographically occult cancer in women with dense breasts using Radon Cumulative Distribution Transform: a preliminary analysis

    Science.gov (United States)

    Lee, Juhun; Nishikawa, Robert M.; Rohde, Gustavo K.

    2018-02-01

    We propose using novel imaging biomarkers for detecting mammographically-occult (MO) cancer in women with dense breast tissue. MO cancer indicates visually occluded, or very subtle, cancer that radiologists fail to recognize as a sign of cancer. We used the Radon Cumulative Distribution Transform (RCDT) as a novel image transformation to project the difference between left and right mammograms into a space, increasing the detectability of occult cancer. We used a dataset of 617 screening full-field digital mammograms (FFDMs) of 238 women with dense breast tissue. Among 238 women, 173 were normal with 2 - 4 consecutive screening mammograms, 552 normal mammograms in total, and the remaining 65 women had an MO cancer with a negative screening mammogram. We used Principal Component Analysis (PCA) to find representative patterns in normal mammograms in the RCDT space. We projected all mammograms to the space constructed by the first 30 eigenvectors of the RCDT of normal cases. Under 10-fold crossvalidation, we conducted quantitative feature analysis to classify normal mammograms and mammograms with MO cancer. We used receiver operating characteristic (ROC) analysis to evaluate the classifier's output using the area under the ROC curve (AUC) as the figure of merit. Four eigenvectors were selected via a feature selection method. The mean and standard deviation of the AUC of the trained classifier on the test set were 0.74 and 0.08, respectively. In conclusion, we utilized imaging biomarkers to highlight differences between left and right mammograms to detect MO cancer using novel imaging transformation.

  10. Adaptive sampling based on the cumulative distribution function of order statistics to delineate heavy-metal contaminated soils using kriging

    International Nuclear Information System (INIS)

    Juang, K.-W.; Lee, D.-Y.; Teng, Y.-L.

    2005-01-01

    Correctly classifying 'contaminated' areas in soils, based on the threshold for a contaminated site, is important for determining effective clean-up actions. Pollutant mapping by means of kriging is increasingly being used for the delineation of contaminated soils. However, those areas where the kriged pollutant concentrations are close to the threshold have a high possibility for being misclassified. In order to reduce the misclassification due to the over- or under-estimation from kriging, an adaptive sampling using the cumulative distribution function of order statistics (CDFOS) was developed to draw additional samples for delineating contaminated soils, while kriging. A heavy-metal contaminated site in Hsinchu, Taiwan was used to illustrate this approach. The results showed that compared with random sampling, adaptive sampling using CDFOS reduced the kriging estimation errors and misclassification rates, and thus would appear to be a better choice than random sampling, as additional sampling is required for delineating the 'contaminated' areas. - A sampling approach was derived for drawing additional samples while kriging

  11. The frequency-independent control method for distributed generation systems

    DEFF Research Database (Denmark)

    Naderi, Siamak; Pouresmaeil, Edris; Gao, Wenzhong David

    2012-01-01

    In this paper a novel frequency-independent control method suitable for distributed generation (DG) is presented. This strategy is derived based on the . abc/. αβ transformation and . abc/. dq transformation of the ac system variables. The active and reactive currents injected by the DG are contr......In this paper a novel frequency-independent control method suitable for distributed generation (DG) is presented. This strategy is derived based on the . abc/. αβ transformation and . abc/. dq transformation of the ac system variables. The active and reactive currents injected by the DG...

  12. Eigenmode frequency distribution of rapidly rotating neutron stars

    International Nuclear Information System (INIS)

    Boutloukos, Stratos; Nollert, Hans-Peter

    2007-01-01

    We use perturbation theory and the relativistic Cowling approximation to numerically compute characteristic oscillation modes of rapidly rotating relativistic stars which consist of a perfect fluid obeying a polytropic equation of state. We present a code that allows the computation of modes of arbitrary order. We focus here on the overall distribution of frequencies. As expected, we find an infinite pressure mode spectrum extending to infinite frequency. In addition we obtain an infinite number of inertial mode solutions confined to a finite, well-defined frequency range which depends on the compactness and the rotation frequency of the star. For nonaxisymmetric modes we observe how this range is shifted with respect to the axisymmetric ones, moving towards negative frequencies and thus making all m>2 modes unstable. We discuss whether our results indicate that the star's spectrum must have a continuous part, as opposed to simply containing an infinite number of discrete modes

  13. Optimizing Power–Frequency Droop Characteristics of Distributed Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Guggilam, Swaroop S.; Zhao, Changhong; Dall Anese, Emiliano; Chen, Yu Christine; Dhople, Sairaj V.

    2018-05-01

    This paper outlines a procedure to design power-frequency droop slopes for distributed energy resources (DERs) installed in distribution networks to optimally participate in primary frequency response. In particular, the droop slopes are engineered such that DERs respond in proportion to their power ratings and they are not unfairly penalized in power provisioning based on their location in the distribution network. The main contribution of our approach is that a guaranteed level of frequency regulation can be guaranteed at the feeder head, while ensuring that the outputs of individual DERs conform to some well-defined notion of fairness. The approach we adopt leverages an optimization-based perspective and suitable linearizations of the power-flow equations to embed notions of fairness and information regarding the physics of the power flows within the distribution network into the droop slopes. Time-domain simulations from a differential algebraic equation model of the 39-bus New England test-case system augmented with three instances of the IEEE 37-node distribution-network with frequency-sensitive DERs are provided to validate our approach.

  14. Seasonally adjusted birth frequencies follow the Poisson distribution.

    Science.gov (United States)

    Barra, Mathias; Lindstrøm, Jonas C; Adams, Samantha S; Augestad, Liv A

    2015-12-15

    Variations in birth frequencies have an impact on activity planning in maternity wards. Previous studies of this phenomenon have commonly included elective births. A Danish study of spontaneous births found that birth frequencies were well modelled by a Poisson process. Somewhat unexpectedly, there were also weekly variations in the frequency of spontaneous births. Another study claimed that birth frequencies follow the Benford distribution. Our objective was to test these results. We analysed 50,017 spontaneous births at Akershus University Hospital in the period 1999-2014. To investigate the Poisson distribution of these births, we plotted their variance over a sliding average. We specified various Poisson regression models, with the number of births on a given day as the outcome variable. The explanatory variables included various combinations of years, months, days of the week and the digit sum of the date. The relationship between the variance and the average fits well with an underlying Poisson process. A Benford distribution was disproved by a goodness-of-fit test (p Poisson process when monthly and day-of-the-week variation is included. The frequency is highest in summer towards June and July, Friday and Tuesday stand out as particularly busy days, and the activity level is at its lowest during weekends.

  15. Allele frequency distribution for 21 autosomal STR loci in Bhutan.

    Science.gov (United States)

    Kraaijenbrink, Thirsa; van Driem, George L; Tshering of Gaselô, Karma; de Knijff, Peter

    2007-07-20

    We studied the allele frequency distribution of 21 autosomal STR loci contained in the AmpFlSTR Identifiler (Applied Biosystems), the Powerplex 16 (Promega) and the FFFL (Promega) multiplex PCR kits among 936 individuals from the Royal Kingdom of Bhutan. As such these are the first published autosomal DNA results from this country.

  16. Influences on flood frequency distributions in Irish river catchments

    Directory of Open Access Journals (Sweden)

    S. Ahilan

    2012-04-01

    Full Text Available This study explores influences on flood frequency distributions in Irish rivers. A Generalised Extreme Value (GEV type I distribution is recommended in Ireland for estimating flood quantiles in a single site flood frequency analysis. This paper presents the findings of an investigation that identified the GEV statistical distributions that best fit the annual maximum (AM data series extracted from 172 gauging stations of 126 rivers in Ireland. Analysis of these data was undertaken to explore hydraulic and hydro-geological factors that influence flood frequency distributions. A hierarchical approach of increasing statistical power that used probability plots, moment and L-moment diagrams, the Hosking goodness of fit algorithm and a modified Anderson-Darling (A-D statistical test was followed to determine whether a type I, type II or type III distribution was valid. Results of the Hosking et al. method indicated that of the 143 stations with flow records exceeding 25 yr, data for 95 (67% was best represented by GEV type I distributions and a further 9 (6% and 39 (27% stations followed type II and type III distributions respectively. Type I, type II and type III distributions were determined for 83 (58%, 16 (11% and 34 (24% stations respectively using the modified A-D method (data from 10 stations was not represented by GEV family distributions. The influence of karst terrain on these flood frequency distributions was assessed by incorporating results on an Arc-GIS platform showing karst features and using Monte Carlo simulations to assess the significance of the number and clustering of the observed distributions. Floodplain effects were identified by using two-sample t-tests to identify statistical correlations between the distributions and catchment properties that are indicative of strong floodplain activity. The data reveals that type I distributions are spatially well represented throughout the country. While also well represented throughout

  17. Similarity of Symbol Frequency Distributions with Heavy Tails

    Directory of Open Access Journals (Sweden)

    Martin Gerlach

    2016-04-01

    Full Text Available Quantifying the similarity between symbolic sequences is a traditional problem in information theory which requires comparing the frequencies of symbols in different sequences. In numerous modern applications, ranging from DNA over music to texts, the distribution of symbol frequencies is characterized by heavy-tailed distributions (e.g., Zipf’s law. The large number of low-frequency symbols in these distributions poses major difficulties to the estimation of the similarity between sequences; e.g., they hinder an accurate finite-size estimation of entropies. Here, we show analytically how the systematic (bias and statistical (fluctuations errors in these estimations depend on the sample size N and on the exponent γ of the heavy-tailed distribution. Our results are valid for the Shannon entropy (α=1, its corresponding similarity measures (e.g., the Jensen-Shanon divergence, and also for measures based on the generalized entropy of order α. For small α’s, including α=1, the errors decay slower than the 1/N decay observed in short-tailed distributions. For α larger than a critical value α^{*}=1+1/γ≤2, the 1/N decay is recovered. We show the practical significance of our results by quantifying the evolution of the English language over the last two centuries using a complete α spectrum of measures. We find that frequent words change more slowly than less frequent words and that α=2 provides the most robust measure to quantify language change.

  18. Frequency and distribution of Notch mutations in tumor cell lines

    International Nuclear Information System (INIS)

    Mutvei, Anders Peter; Fredlund, Erik; Lendahl, Urban

    2015-01-01

    Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

  19. Simple method of generating and distributing frequency-entangled qudits

    Science.gov (United States)

    Jin, Rui-Bo; Shimizu, Ryosuke; Fujiwara, Mikio; Takeoka, Masahiro; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Gerrits, Thomas; Sasaki, Masahide

    2016-11-01

    High-dimensional, frequency-entangled photonic quantum bits (qudits for d-dimension) are promising resources for quantum information processing in an optical fiber network and can also be used to improve channel capacity and security for quantum communication. However, up to now, it is still challenging to prepare high-dimensional frequency-entangled qudits in experiments, due to technical limitations. Here we propose and experimentally implement a novel method for a simple generation of frequency-entangled qudts with d\\gt 10 without the use of any spectral filters or cavities. The generated state is distributed over 15 km in total length. This scheme combines the technique of spectral engineering of biphotons generated by spontaneous parametric down-conversion and the technique of spectrally resolved Hong-Ou-Mandel interference. Our frequency-entangled qudits will enable quantum cryptographic experiments with enhanced performances. This distribution of distinct entangled frequency modes may also be useful for improved metrology, quantum remote synchronization, as well as for fundamental test of stronger violation of local realism.

  20. Frequency distributions from birth, death, and creation processes.

    Science.gov (United States)

    Bartley, David L; Ogden, Trevor; Song, Ruiguang

    2002-01-01

    The time-dependent frequency distribution of groups of individuals versus group size was investigated within a continuum approximation, assuming a simplified individual growth, death and creation model. The analogy of the system to a physical fluid exhibiting both convection and diffusion was exploited in obtaining various solutions to the distribution equation. A general solution was approximated through the application of a Green's function. More specific exact solutions were also found to be useful. The solutions were continually checked against the continuum approximation through extensive simulation of the discrete system. Over limited ranges of group size, the frequency distributions were shown to closely exhibit a power-law dependence on group size, as found in many realizations of this type of system, ranging from colonies of mutated bacteria to the distribution of surnames in a given population. As an example, the modeled distributions were successfully fit to the distribution of surnames in several countries by adjusting the parameters specifying growth, death and creation rates.

  1. Frequency distribution function of stellar flares in the Orion association

    International Nuclear Information System (INIS)

    Parsamian, E.S.

    1981-01-01

    The temporal distributions of flare stars in the Orion association and the numbers of stars with different flare frequencies are determined by means of Ambartsumian's (1978) method, which uses the chronology of discovery of 'first' flares and the chronology of confirmations, i.e., the temporal distributions of 'repeated' flares. It is shown that flare stars with high flare frequency (not greater than 1000 hours) in the Pleiades are basically stars of low luminosity with M(U) not less than 13m. Two independent methods of determining the number of flare stars in the aggregates confirm that there are about 1.5 times more flare stars in the Orion association than in the Pleiades

  2. Allele frequency distribution for 21 autosomal STR loci in Nepal.

    Science.gov (United States)

    Kraaijenbrink, T; van Driem, G L; Opgenort, J R M L; Tuladhar, N M; de Knijff, P

    2007-05-24

    The allele frequency distributions of 21 autosomal loci contained in the AmpFlSTR Identifiler, the Powerplex 16 and the FFFL multiplex PCR kits, was studied in 953 unrelated individuals from Nepal. Several new alleles (i.e. not yet reported in the NIST Short Tandem Repeat DNA Internet DataBase [http://www.cstl.nist.gov/biotech/strbase/]) have been detected in the process.

  3. Frequency distributions: from the sun to the earth

    Directory of Open Access Journals (Sweden)

    N. B. Crosby

    2011-11-01

    Full Text Available The space environment is forever changing on all spatial and temporal scales. Energy releases are observed in numerous dynamic phenomena (e.g. solar flares, coronal mass ejections, solar energetic particle events where measurements provide signatures of the dynamics. Parameters (e.g. peak count rate, total energy released, etc. describing these phenomena are found to have frequency size distributions that follow power-law behavior. Natural phenomena on Earth, such as earthquakes and landslides, display similar power-law behavior. This suggests an underlying universality in nature and poses the question of whether the distribution of energy is the same for all these phenomena. Frequency distributions provide constraints for models that aim to simulate the physics and statistics observed in the individual phenomenon. The concept of self-organized criticality (SOC, also known as the "avalanche concept", was introduced by Bak et al. (1987, 1988, to characterize the behavior of dissipative systems that contain a large number of elements interacting over a short range. The systems evolve to a critical state in which a minor event starts a chain reaction that can affect any number of elements in the system. It is found that frequency distributions of the output parameters from the chain reaction taken over a period of time can be represented by power-laws. During the last decades SOC has been debated from all angles. New SOC models, as well as non-SOC models have been proposed to explain the power-law behavior that is observed. Furthermore, since Bak's pioneering work in 1987, people have searched for signatures of SOC everywhere. This paper will review how SOC behavior has become one way of interpreting the power-law behavior observed in natural occurring phenomenon in the Sun down to the Earth.

  4. Distributive estimation of frequency selective channels for massive MIMO systems

    KAUST Repository

    Zaib, Alam

    2015-12-28

    We consider frequency selective channel estimation in the uplink of massive MIMO-OFDM systems, where our major concern is complexity. A low complexity distributed LMMSE algorithm is proposed that attains near optimal channel impulse response (CIR) estimates from noisy observations at receive antenna array. In proposed method, every antenna estimates the CIRs of its neighborhood followed by recursive sharing of estimates with immediate neighbors. At each step, every antenna calculates the weighted average of shared estimates which converges to near optimal LMMSE solution. The simulation results validate the near optimal performance of proposed algorithm in terms of mean square error (MSE). © 2015 EURASIP.

  5. Single Frequency Network Based Distributed Passive Radar Technology

    Directory of Open Access Journals (Sweden)

    Wan Xian-rong

    2015-01-01

    Full Text Available The research and application of passive radar are heading from single transmitter-receiver pair to multiple transmitter-receiver pairs. As an important class of the illuminators of opportunity, most of modern digital broadcasting and television systems work on Single Frequency Network (SFN, which intrinsically determines that the passive radar based on such illuminators must be distributed and networked. In consideration of the remarkable working and processing mode of passive radar under SFN configuration, this paper proposes the concept of SFN-based Distributed Passive Radar (SDPR. The main characteristics and key problems of SDPR are first described. Then several potential solutions are discussed for part of the key technologies. The feasibility of SDPR is demonstrated by preliminary experimental results. Finally, the concept of four network convergence that includes the broadcast based passive radar network is conceived, and its application prospects are discussed.

  6. A Monte Carlo procedure for the construction of complementary cumulative distribution functions for comparison with the EPA release limits for radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Helton, J.C.; Shiver, A.W.

    1994-10-01

    A Monte Carlo procedure for the construction of complementary cumulative distribution functions (CCDFs) for comparison with the US Environmental Protection Agency (EPA) release limits for radioactive waste disposal (40 CFR 191, Subpart B) is described and illustrated with results from a recent performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP). The Monte Carlo procedure produces CCDF estimates similar to those obtained with stratified sampling in several recent PAs for the WIPP. The advantages of the Monte Carlo procedure over stratified sampling include increased resolution in the calculation of probabilities for complex scenarios involving drilling intrusions and better use of the necessarily limited number of mechanistic calculations that underlie CCDF construction.

  7. A Monte Carlo procedure for the construction of complementary cumulative distribution functions for comparison with the EPA release limits for radioactive waste disposal

    International Nuclear Information System (INIS)

    Helton, J.C.; Shiver, A.W.

    1994-10-01

    A Monte Carlo procedure for the construction of complementary cumulative distribution functions (CCDFs) for comparison with the US Environmental Protection Agency (EPA) release limits for radioactive waste disposal (40 CFR 191, Subpart B) is described and illustrated with results from a recent performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP). The Monte Carlo procedure produces CCDF estimates similar to those obtained with stratified sampling in several recent PAs for the WIPP. The advantages of the Monte Carlo procedure over stratified sampling include increased resolution in the calculation of probabilities for complex scenarios involving drilling intrusions and better use of the necessarily limited number of mechanistic calculations that underlie CCDF construction

  8. Incoherent Optical Frequency Domain Reflectometry for Distributed Thermal Sensing

    DEFF Research Database (Denmark)

    Karamehmedovic, Emir

    2006-01-01

    comprising a pump laser, optical filters, optical fibre and photo-detectors are presented. Limitations, trade-offs and optimisation processes are described for setups having different specifications with respect to range, resolution and accuracy. The analysis is conducted using computer simulation programs...... developed and implemented in Matlab. The computer model is calibrated and tested, and describes the entire system with high precision. Noise analysis and digital processing of the detected signal are discussed as well. An equation describing the standard deviation of the measured temperature is derived......This thesis reports the main results from an investigation of a fibre-optic distributed temperature sensor based on spontaneous Raman scattering. The technique used for spatial resolving is the incoherent optical frequency domain reflectometry, where a pump laser is sine modulated with a stepwise...

  9. LAW DISTRIBUTION APPROXIMATION ON EIGENSTATE ERRORS OF ADS-B BASED ON CUMULANT ANALYSIS OF ADS-B-RAD SYSTEM DATA DISPARITY

    Directory of Open Access Journals (Sweden)

    2017-01-01

    Full Text Available The article deals with a new approximation method for enhanced accuracy measurement system errors distribu- tion. The method is based upon the mistie analysis of this system and a more robust design data. The method is considered on the example of comparison of Automatic Dependent Surveillance - Broadcast (ADS-B with ground radar warning sys- tem used at present. The peculiarity of the considered problem is that the target parameter (aircraft swerve value may dras- tically change in the scale of both measurement systems errors during observation. That is why it is impossible to determine the position of the aircraft by repeatedly observing it with ground radar warning system. It is only possible to compare the systems’ one-shot measurements, which are called errors here. The article considers that the distribution of robust meas- urement system errors probability density (the system that has been continuously in operation is known, the histogram of errors is given and it is needed to obtain an asymptotic estimate of errors occurrence distribution for a new improved meas- urement system.This approach is based on cumulant analysis of measurement systems error distribution functions. The approach allows us to carry out the reduction of corresponding infinite series properly. The author shows that due to measurement systems independency, their errors distribution cumulants are connected by a simple ratio, which allow to calculate the val- ues easily. To reconstruct distribution initial form one should use Edgeworth’s asymptotic series, where a normal distribu- tion derivative is used as a basis function. The latter is proportional to Hermitian polynomial, thus the series can be consid- ered as an orthogonal decomposition.The author reveals the results of coordinate error component distribution calculation; the error is measured when the normal line lies towards aircraft path, using error statistics experimental information obtained in ”RI of

  10. LPI Radar Waveform Recognition Based on Time-Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-10-01

    Full Text Available In this paper, an automatic radar waveform recognition system in a high noise environment is proposed. Signal waveform recognition techniques are widely applied in the field of cognitive radio, spectrum management and radar applications, etc. We devise a system to classify the modulating signals widely used in low probability of intercept (LPI radar detection systems. The radar signals are divided into eight types of classifications, including linear frequency modulation (LFM, BPSK (Barker code modulation, Costas codes and polyphase codes (comprising Frank, P1, P2, P3 and P4. The classifier is Elman neural network (ENN, and it is a supervised classification based on features extracted from the system. Through the techniques of image filtering, image opening operation, skeleton extraction, principal component analysis (PCA, image binarization algorithm and Pseudo–Zernike moments, etc., the features are extracted from the Choi–Williams time-frequency distribution (CWD image of the received data. In order to reduce the redundant features and simplify calculation, the features selection algorithm based on mutual information between classes and features vectors are applied. The superiority of the proposed classification system is demonstrated by the simulations and analysis. Simulation results show that the overall ratio of successful recognition (RSR is 94.7% at signal-to-noise ratio (SNR of −2 dB.

  11. A Robust Function to Return the Cumulative Density of Non-Central F Distributions in Microsoft Office Excel

    Science.gov (United States)

    Nelson, James Byron

    2016-01-01

    The manuscript presents a Visual Basic[superscript R] for Applications function that operates within Microsoft Office Excel[superscript R] to return the area below the curve for a given F within a specified non-central F distribution. The function will be of use to Excel users without programming experience wherever a non-central F distribution is…

  12. Landslide scaling and magnitude-frequency distribution (Invited)

    Science.gov (United States)

    Stark, C. P.; Guzzetti, F.

    2009-12-01

    Landslide-driven erosion is controlled by the scale and frequency of slope failures and by the consequent fluxes of debris off the hillslopes. Here I focus on the magnitude-frequency part of the process and develop a theory of initial slope failure and debris mobilization that reproduces the heavy-tailed distributions (PDFs) observed for landslide source areas and volumes. Landslide rupture propagation is treated as a quasi-static, non-inertial process of simplified elastoplastic deformation with strain weakening; debris runout is not considered. The model tracks the stochastically evolving imbalance of frictional, cohesive, and body forces across a failing slope, and uses safety-factor concepts to convert the evolving imbalance into a series of incremental rupture growth or arrest probabilities. A single rupture is simulated with a sequence of weighted ``coin tosses'' with weights set by the growth probabilities. Slope failure treated in this stochastic way is a survival process that generates asymptotically power-law-tail PDFs of area and volume for rock and debris slides; predicted scaling exponents are consistent with analyses of landslide inventories. The primary control on the shape of the model PDFs is the relative importance of cohesion over friction in setting slope stability: the scaling of smaller, shallower failures, and the size of the most common landslide volumes, are the result of the low cohesion of soil and regolith, whereas the negative power-law tail scaling for larger failures is tied to the greater cohesion of bedrock. The debris budget may be dominated by small or large landslides depending on the scaling of both the PDF and of the depth-length relation. I will present new model results that confirm the hypothesis that depth-length scaling is linear. Model PDF of landslide volumes.

  13. [Frequency distribution of dibucaine numbers in 24,830 patients].

    Science.gov (United States)

    Pestel, G; Sprenger, H; Rothhammer, A

    2003-06-01

    Atypical cholinesterase prolongs the duration of neuromuscular blocking drugs such as succinylcholine and mivacurium. Measuring the dibucaine number identifies patients who are at risk. This study shows the frequency distribution of dibucaine numbers routinely measured and discusses avoidable clinical problems and economic implications. Dibucaine numbers were measured on a Hitachi 917-analyzer and all dibucaine numbers recorded over a period of 4 years were taken into consideration. Repeat observations were excluded. A total of 24,830 dibucaine numbers were analysed and numbers below 30 were found in 0.07% ( n=18) giving an incidence of 1:1,400. Dibucaine numbers from 30 to 70 were found in 1.23% ( n=306). On the basis of identification of the Dibucaine numbers we could avoid the administration of succinylcholine or mivacurium resulting in a cost reduction of 12,280 Euro offset against the total laboratory costs amounting to 10,470 Euro. An incidence of 1:1,400 of dibucaine numbers below 30 is higher than documented in the literature. Therefore, routine measurement of dibucaine number is a cost-effective method of identifying patients at increased risk of prolonged neuromuscular blockade due to atypical cholinesterase.

  14. Combining scenarios in a calculation of the overall probability distribution of cumulative releases of radioactivity from the Waste Isolation Pilot Plant, southeastern New Mexico

    International Nuclear Information System (INIS)

    Tierney, M.S.

    1991-11-01

    The Waste Isolation Pilot Plant (WIPP), in southeastern New Mexico, is a research and development facility to demonstrate safe disposal of defense-generated transuranic waste. The US Department of Energy will designate WIPP as a disposal facility if it meets the US Environmental Protection Agency's standard for disposal of such waste; the standard includes a requirement that estimates of cumulative releases of radioactivity to the accessible environment be incorporated in an overall probability distribution. The WIPP Project has chosen an approach to calculation of an overall probability distribution that employs the concept of scenarios for release and transport of radioactivity to the accessible environment. This report reviews the use of Monte Carlo methods in the calculation of an overall probability distribution and presents a logical and mathematical foundation for use of the scenario concept in such calculations. The report also draws preliminary conclusions regarding the shape of the probability distribution for the WIPP system; preliminary conclusions are based on the possible occurrence of three events and the presence of one feature: namely, the events ''attempted boreholes over rooms and drifts,'' ''mining alters ground-water regime,'' ''water-withdrawal wells provide alternate pathways,'' and the feature ''brine pocket below room or drift.'' Calculation of the WIPP systems's overall probability distributions for only five of sixteen possible scenario classes that can be obtained by combining the four postulated events or features

  15. Tuningless Load Frequency Control Through Active Engagement of Distributed Resources

    DEFF Research Database (Denmark)

    Prostejovsky, Alexander; Marinelli, Mattia; Rezkalla, Michel M.N.

    2017-01-01

    system dynamics. Second, primary resources are actively involved in frequency restoration by systematic adjustment of their frequency reference setpoints. In contrast to the commonly used Automatic Generation Control (AGC), the proposed Direct Load Frequency Control (DLFC) does not require an integrator...

  16. An Empirical Method to Derive Hourly Temperature Frequencies for Locations Possessing Only Summarized Climate Information

    National Research Council Canada - National Science Library

    Krause, Paul

    1997-01-01

    ... thresholds are equaled or exceeded. Prior research focused on both estimating temperature frequencies at any point along the cumulative temperature frequency curve, and on estimation at fixed frequency points within the tails of the distribution...

  17. 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)

  18. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: cuttings, cavings and spallings

    International Nuclear Information System (INIS)

    Berglund, J.W.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Smith, L.N.

    2000-01-01

    The following topics related to the treatment of cuttings, cavings and spallings 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 results indicate that direct releases due to cuttings, cavings and spallings 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 cuttings, cavings and spallings 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)

  19. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: Cuttings, cavings and spallings

    International Nuclear Information System (INIS)

    Berglund, J.W.; Garner, J.W.; Helton, Jon Craig; Johnson, J.D.; Smith, L.N.; Anderson, R.P.

    2000-01-01

    The following topics related to the treatment of cuttings, cavings and spallings releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (1) mathematical description of models. (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that direct releases due to cuttings, cavings and spallings 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 cuttings, cavings and spallings releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

  20. CUMBIN - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, CUMBIN, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), can be used independently of one another. CUMBIN can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. CUMBIN calculates the probability that a system of n components has at least k operating if the probability that any one operating is p and the components are independent. Equivalently, this is the reliability of a k-out-of-n system having independent components with common reliability p. CUMBIN can evaluate the incomplete beta distribution for two positive integer arguments. CUMBIN can also evaluate the cumulative F distribution and the negative binomial distribution, and can determine the sample size in a test design. CUMBIN is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. The program is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. The CUMBIN 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 with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. CUMBIN was developed in 1988.

  1. Cumulative Distributions and Flow Structure of Two-Passage Shear Coaxial Injector with Various Gas Injection Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Inchul; Kim, Dohun; Koo, Jaye [Korea Aerospace Univ., Goyang (Korea, Republic of)

    2013-07-15

    To verify the effect of inner- and outer-stage gas jets, a shear coaxial injector was designed to analyze the axial velocity profile and breakup phenomenon with an increase in the measurement distance. When the measurement position was increased to Z/d=100, the axial flow showed a fully developed shape due to the momentum transfer, aerodynamic drag effect, and viscous mixing. An inner gas injection, which induces a higher momentum flux ratio near the nozzle, produces the greater shear force on atomization than an outer gas injection. Inner- and Outer-stage gas injection do not affect the mixing between the inner and outer gas flow below Z/d=5. The experiment results showed that the main effect of liquid jet breakup was governed by the gas jet of an inner stage. As the nozzle exit of the outer-stage was located far from the liquid column, shear force and turbulence breaking up of the liquid jets do not fully affect the liquid column. In the case of an inner-stage gas injection momentum flux ratio within 0.84, with the increase in the outer gas momentum flux ratio, the Smd decreases. However, at an inner-stage gas jet momentum flux ratio over 1.38, the Smd shows the similar distribution.

  2. Low Frequency Electrostatic Waves in Weakly Inhomogeneous Magnetoplasma Modeled by Lorentzian (kappa) Distributions

    National Research Council Canada - National Science Library

    Basu, Bamandas

    2008-01-01

    ... (to the ambient magnetic field) flow velocities associated with the current. In order to illustrate the distinguishing features of the kappa distributions, stability properties of the low frequency...

  3. Comparative frequency and allelic distribution of ABO and Rh (D ...

    African Journals Online (AJOL)

    Gourab Dewan

    2015-02-18

    Feb 18, 2015 ... desh and having borders with India and Myanmar (Fig. 1). It is a hilly area with ..... calculated allelic frequencies for ABO/Rh systems previously. Therefore, allelic .... in backward caste population of Uttar Pradesh, India. Not Sci.

  4. Dynamic Response to Pedestrian Loads with Statistical Frequency Distribution

    DEFF Research Database (Denmark)

    Krenk, Steen

    2012-01-01

    on the magnitude of the resulting response. A frequency representation of vertical pedestrian load is developed, and a compact explicit formula is developed for the magnitude of the resulting response, in terms of the damping ratio of the structure, the bandwidth of the pedestrian load, and the mean footfall...... frequency. The accuracy of the formula is verified by a statistical moment analysis using the Lyapunov equations....

  5. Geographical distribution of hot flash frequencies: considering climatic influences.

    Science.gov (United States)

    Sievert, Lynnette Leidy; Flanagan, Erin K

    2005-10-01

    Laboratory studies suggest that hot flashes are triggered by small elevations in core body temperature acting within a reduced thermoneutral zone, i.e., the temperature range in which a woman neither shivers nor sweats. In the present study, it was hypothesized that women in different populations develop climate-specific thermoneutral zones, and ultimately, population-specific frequencies of hot flashes at menopause. Correlations were predicted between hot flash frequencies and latitude, elevation, and annual temperatures. Data on hot flash frequencies were drawn from 54 studies. Pearson correlation analyses and simple linear regressions were applied, first using all studies, and second using a subset of studies that included participants only to age 60 (n = 36). Regressions were repeated with all studies, controlling for method of hot flash assessment. When analyses were restricted to studies that included women up to age 60, average temperature of the coldest month was a significant predictor of hot flash frequency (P hottest and coldest temperatures was also a significant predictor (P coldest month, difference between hottest and coldest temperatures, and mean annual temperature were significant predictors of hot flash frequency. Women reported fewer hot flashes in warmer temperatures, and more hot flashes with increasing seasonality. These results suggest that acclimatization to coldest temperatures or sensitivity to seasonality may explain part of the population variation in hot flash frequency.

  6. Statistical Tests for Frequency Distribution of Mean Gravity Anomalies

    African Journals Online (AJOL)

    The hypothesis that a very large number of lOx 10mean gravity anomalies are normally distributed has been rejected at 5% Significance level based on the X2 and the unit normal deviate tests. However, the 50 equal area mean anomalies derived from the lOx 10data, have been found to be normally distributed at the same ...

  7. Frequency distribution 0f ABO, RH blood groups and blood ...

    African Journals Online (AJOL)

    One hundred and fifty students (150) were randomly selected from the Department of Cell Biology and Genetics of University of Lagos, Akoka, Nigeria for ABO, RH blood groups and 6 haemoglobin genotypes studies. Blood group O was the highest with the percentage frequency of 55.3%, followed by blood group A (25.3%) ...

  8. Entropy-based derivation of generalized distributions for hydrometeorological frequency analysis

    Science.gov (United States)

    Chen, Lu; Singh, Vijay P.

    2018-02-01

    Frequency analysis of hydrometeorological and hydrological extremes is needed for the design of hydraulic and civil infrastructure facilities as well as water resources management. A multitude of distributions have been employed for frequency analysis of these extremes. However, no single distribution has been accepted as a global standard. Employing the entropy theory, this study derived five generalized distributions for frequency analysis that used different kinds of information encoded as constraints. These distributions were the generalized gamma (GG), the generalized beta distribution of the second kind (GB2), and the Halphen type A distribution (Hal-A), Halphen type B distribution (Hal-B) and Halphen type inverse B distribution (Hal-IB), among which the GG and GB2 distribution were previously derived by Papalexiou and Koutsoyiannis (2012) and the Halphen family was first derived using entropy theory in this paper. The entropy theory allowed to estimate parameters of the distributions in terms of the constraints used for their derivation. The distributions were tested using extreme daily and hourly rainfall data. Results show that the root mean square error (RMSE) values were very small, which indicated that the five generalized distributions fitted the extreme rainfall data well. Among them, according to the Akaike information criterion (AIC) values, generally the GB2 and Halphen family gave a better fit. Therefore, those general distributions are one of the best choices for frequency analysis. The entropy-based derivation led to a new way for frequency analysis of hydrometeorological extremes.

  9. Time-frequency distributions for propulsion-system diagnostics

    Science.gov (United States)

    Griffin, Michael E.; Tulpule, Sharayu

    1991-12-01

    The Wigner distribution and its smoothed versions, i.e., Choi-Williams and Gaussian kernels, are evaluated for propulsion system diagnostics. The approach is intended for off-line kernel design by using the ambiguity domain to select the appropriate Gaussian kernel. The features produced by the Wigner distribution and its smoothed versions correlate remarkably well with documented failure indications. The selection of the kernel on the other hand is very subjective for our unstructured data.

  10. Time-Frequency Distribution of Music based on Sparse Wavelet Packet Representations

    DEFF Research Database (Denmark)

    Endelt, Line Ørtoft

    We introduce a new method for generating time-frequency distributions, which is particularly useful for the analysis of music signals. The method presented here is based on $\\ell1$ sparse representations of music signals in a redundant wavelet packet dictionary. The representations are found using...... the minimization methods basis pursuit and best orthogonal basis. Visualizations of the time-frequency distribution are constructed based on a simplified energy distribution in the wavelet packet decomposition. The time-frequency distributions emphasizes structured musical content, including non-stationary content...

  11. A note on frequency distributions of fission tracks in apatite

    International Nuclear Information System (INIS)

    He, Z.; Lerche, I.

    1989-01-01

    Two different formulae, both purportedly describing track length reduction in apatite, are converted to forms useful in prediction of track length distributions along sedimentary burial history paths. Using the formalism, track length distribution data from four NW Canning Basin wells are inverted to determine the physical (chemical) parameters associated with the models as well as the heat flux variation with time. For each formula the resulting physical parameters are consistent among the wells tested but differ from laboratory-derived parameter values, and the thermal histories are consistent with those inferred from geological data. Comparison of the two models shows no evidence that one model should be favored over the other based on the data available. It is also shown that the resolution of the parameters is dependent not only on the quantity of the data but also on the ''quality'' -explicitly upon the variation and distribution with depth. (author)

  12. NEWTONP - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, NEWTONP, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, NEWTONP, CUMBIN (NPO-17555), and CROSSER (NPO-17557), can be used independently of one another. NEWTONP can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. NEWTONP calculates the probably p required to yield a given system reliability V for a k-out-of-n system. It can also be used to determine the Clopper-Pearson confidence limits (either one-sided or two-sided) for the parameter p of a Bernoulli distribution. NEWTONP can determine Bayesian probability limits for a proportion (if the beta prior has positive integer parameters). It can determine the percentiles of incomplete beta distributions with positive integer parameters. It can also determine the percentiles of F distributions and the midian plotting positions in probability plotting. NEWTONP is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. NEWTONP is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. It also lists the number of iterations of Newton's method required to calculate the answer within the given error. The NEWTONP 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 with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. NEWTONP was developed in 1988.

  13. Radionuclide transport in the vicinity of the repository and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Stockman, C.T.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Shinta, A.; Smith, L.N.

    2000-01-01

    The following topics related to radionuclide transport in the vicinity of the repository in the 1996 performance assessment for the Waste Isolation Pilot Plant 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 results indicate that no releases to the accessible environment take place due to radionuclide movement through the anhydrite marker beds, through the Dewey Lake Red Beds or directly to the surface, and also that the releases to the Culebra Dolomite are small. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for release to the Culebra Dolomite fall 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)

  14. Radionuclide and colloid transport in the Culebra Dolomite and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    RAMSEY, JAMES L.; BLAINE,R.; GARNER,J.W.; HELTON,JON CRAIG; JOHNSON,J.D.; SMITH,L.N.; WALLACE,M.

    2000-05-22

    The following topics related to radionuclide and colloid transport in the Culebra Dolomite in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (1) mathematical description of models, (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, and (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty. The presented results indicate that radionuclide and colloid transport in the Culebra Dolomite does 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, no radionuclide transport to the boundary with the accessible environment was observed; thus the associated CCDFs for comparison with 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) are degenerate in the sense of having a probability of zero of exceeding a release of zero.

  15. Non extensivity and frequency magnitude distribution of earthquakes

    International Nuclear Information System (INIS)

    Sotolongo-Costa, Oscar; Posadas, Antonio

    2003-01-01

    Starting from first principles (in this case a non-extensive formulation of the maximum entropy principle) and a phenomenological approach, an explicit formula for the magnitude distribution of earthquakes is derived, which describes earthquakes in the whole range of magnitudes. The Gutenberg-Richter law appears as a particular case of the obtained formula. Comparison with geophysical data gives a very good agreement

  16. Frequency distribution of Foraminifera in the Chilka lake

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.; Rao, K.K.

    -349. Clifford, H.T. and W. Stephenson. 1975. An intro- duction to numerical classification, Academic Press, New York, 225 pp. Field, J.G., K.R. Clarke and R.M. Warwick. 1982. A practical strategy for analyzing multispecies distribution patterns. Mar. Ecol...

  17. HYPOCENTER DISTRIBUTION OF LOW FREQUENCY EVENT AT PAPANDAYAN VOLCANO

    Directory of Open Access Journals (Sweden)

    Muhammad Mifta Hasan

    2016-10-01

    Full Text Available Papandayan volcano is a stratovolcano with irregular cone-shaped has eight craters around the peak. The most active crater in Papandayan is a Mas crater. Distribution of relocated event calculated using Geiger Adaptive Damping Algorithm (GAD shows that the epicenter of the event centered below Mas crater with maximum rms 0.114. While depth of the hypocenter range between 0-2 km and 5-6 km due to activity of steam and gas.

  18. Fully Stochastic Distributed Methodology for Multivariate Flood Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Isabel Flores-Montoya

    2016-05-01

    Full Text Available An adequate estimation of the extreme behavior of basin response is essential both for designing river structures and for evaluating their risk. The aim of this paper is to develop a new methodology to generate extreme hydrograph series of thousands of years using an event-based model. To this end, a spatial-temporal synthetic rainfall generator (RainSimV3 is combined with a distributed physically-based rainfall–runoff event-based model (RIBS. The use of an event-based model allows simulating longer hydrograph series with less computational and data requirements but need to characterize the initial basis state, which depends on the initial basin moisture distribution. To overcome this problem, this paper proposed a probabilistic calibration–simulation approach, which considers the initial state and the model parameters as random variables characterized by a probability distribution though a Monte Carlo simulation. This approach is compared with two other approaches, the deterministic and the semi-deterministic approaches. Both approaches use a unique initial state. The deterministic approach also uses a unique value of the model parameters while the semi-deterministic approach obtains these values from its probability distribution through a Monte Carlo simulation, considering the basin variability. This methodology has been applied to the Corbès and Générargues basins, in the Southeast of France. The results show that the probabilistic approach offers the best fit. That means that the proposed methodology can be successfully used to characterize the extreme behavior of the basin considering the basin variability and overcoming the basin initial state problem.

  19. CROSSER - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, CROSSER, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, CROSSER, CUMBIN (NPO-17555), and NEWTONP (NPO-17556), can be used independently of one another. CROSSER can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. CROSSER calculates the point at which the reliability of a k-out-of-n system equals the common reliability of the n components. It is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. The program is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. It also lists the number of iterations of Newton's method required to calculate the answer within the given error. The CROSSER 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 with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. CROSSER was developed in 1988.

  20. Text mixing shapes the anatomy of rank-frequency distributions

    Science.gov (United States)

    Williams, Jake Ryland; Bagrow, James P.; Danforth, Christopher M.; Dodds, Peter Sheridan

    2015-05-01

    Natural languages are full of rules and exceptions. One of the most famous quantitative rules is Zipf's law, which states that the frequency of occurrence of a word is approximately inversely proportional to its rank. Though this "law" of ranks has been found to hold across disparate texts and forms of data, analyses of increasingly large corpora since the late 1990s have revealed the existence of two scaling regimes. These regimes have thus far been explained by a hypothesis suggesting a separability of languages into core and noncore lexica. Here we present and defend an alternative hypothesis that the two scaling regimes result from the act of aggregating texts. We observe that text mixing leads to an effective decay of word introduction, which we show provides accurate predictions of the location and severity of breaks in scaling. Upon examining large corpora from 10 languages in the Project Gutenberg eBooks collection, we find emphatic empirical support for the universality of our claim.

  1. Damage Detection Based on Cross-Term Extraction from Bilinear Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Ma Yuchao

    2014-01-01

    Full Text Available Abundant damage information is implicated in the bilinear time-frequency distribution of structural dynamic signals, which could provide effective support for structural damage identification. Signal time-frequency analysis methods are reviewed, and the characters of linear time-frequency distribution and bilinear time-frequency distribution typically represented by the Wigner-Ville distribution are compared. The existence of the cross-term and its application in structural damage detection are demonstrated. A method of extracting the dominant term is proposed, which combines the short-time Fourier spectrum and Wigner-Ville distribution; then two-dimensional time-frequency transformation matrix is constructed and the complete cross-term is extracted finally. The distribution character of which could be applied to the structural damage identification. Through theoretical analysis, model experiment and numerical simulation of the girder structure, the change rate of cross-term amplitude is validated to identify the damage location and degree. The effectiveness of the cross-term of bilinear time-frequency distribution for damage detection is confirmed and the analytical method of damage identification used in structural engineering is available.

  2. Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

    Science.gov (United States)

    Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

    2017-05-24

    In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

  3. Secondary Frequency and Voltage Control of Islanded Microgrids via Distributed Averaging

    DEFF Research Database (Denmark)

    W. Simpson-Porco, John; Shafiee, Qobad; Dorfler, Florian

    2015-01-01

    actions. The frequency controller rapidly regulates the microgrid frequency to its nominal value while maintaining active power sharing among the distributed generators. Tuning of the voltage controller provides a simple and intuitive trade-off between the conflicting goals of voltage regulation...

  4. Daris, a low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Bentum, Marinus Jan; van 't Klooster, K.; Falcke, H.

    2010-01-01

    DARIS (Distributed Aperture Array for Radio Astronomy in Space) is a radio astronomy space mission concept aimed at observing the low-frequency radio sky in the range 1-10 MHz. Because of the Earth's ionospheric disturbances and opaqueness, this frequency range can only be observed from space. The

  5. Highly stable microwave carrier generation using a dual-frequency distributed feedback laser

    NARCIS (Netherlands)

    Khan, M.R.H.; Bernhardi, Edward; Marpaung, D.A.I.; Burla, M.; de Ridder, R.M.; Worhoff, Kerstin; Pollnau, Markus; Roeloffzen, C.G.H.

    2012-01-01

    Photonic generation of microwave carriers by using a dual-frequency distributed feedback waveguide laser in ytterbium-doped aluminum oxide is demonstrated. A highperformance optical frequency locked loop is implemented to stabilize the microwave carrier. This approach results in a microwave

  6. The Influence of Orthographic Neighborhood Density and Word Frequency on Visual Word Recognition: Insights from RT Distributional Analyses

    Directory of Open Access Journals (Sweden)

    Stephen Wee Hun eLim

    2016-03-01

    Full Text Available The effects of orthographic neighborhood density and word frequency in visual word recognition were investigated using distributional analyses of response latencies in visual lexical decision. Main effects of density and frequency were observed in mean latencies. Distributional analyses, in addition, revealed a density x frequency interaction: for low-frequency words, density effects were mediated predominantly by distributional shifting whereas for high-frequency words, density effects were absent except at the slower RTs, implicating distributional skewing. The present findings suggest that density effects in low-frequency words reflect processes involved in early lexical access, while the effects observed in high-frequency words reflect late postlexical checking processes.

  7. Time-frequency representation of a highly nonstationary signal via the modified Wigner distribution

    Science.gov (United States)

    Zoladz, T. F.; Jones, J. H.; Jong, J.

    1992-01-01

    A new signal analysis technique called the modified Wigner distribution (MWD) is presented. The new signal processing tool has been very successful in determining time frequency representations of highly non-stationary multicomponent signals in both simulations and trials involving actual Space Shuttle Main Engine (SSME) high frequency data. The MWD departs from the classic Wigner distribution (WD) in that it effectively eliminates the cross coupling among positive frequency components in a multiple component signal. This attribute of the MWD, which prevents the generation of 'phantom' spectral peaks, will undoubtedly increase the utility of the WD for real world signal analysis applications which more often than not involve multicomponent signals.

  8. Distribution function of frequency of stellar flares in the Orion association

    International Nuclear Information System (INIS)

    Parsamyan, Eh.S.

    1980-01-01

    Using the chronology of discoveries of new flares and the chronology of confirmation i.e. the time distribution of second flares (Ambartsumian's method), the distribution function of frequency of flares on stars in the Orion association is obtained. A number of stars having different frequencies is also found. It is shown that flare stars with high flare frequency (ν -1 13sup(m). The quantities of flare stars in aggregates determined by two independent methods show that the number of flare stars in Orion association is about 1.5 times greater than in the Pleiades cluster [ru

  9. System-Reliability Cumulative-Binomial Program

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, NEWTONP, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. NEWTONP, CUMBIN (NPO-17555), and CROSSER (NPO-17557), used independently of one another. Program finds probability required to yield given system reliability. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Program written in C.

  10. Common-Reliability Cumulative-Binomial Program

    Science.gov (United States)

    Scheuer, Ernest, M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CROSSER, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CROSSER, CUMBIN (NPO-17555), and NEWTONP (NPO-17556), used independently of one another. Point of equality between reliability of system and common reliability of components found. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Program written in C.

  11. Frequency distribution of the reduced unit cells of centred lattices from the Protein Data Bank.

    Science.gov (United States)

    Swaminathan, Kunchithapadam

    2012-03-01

    In crystallography, a centred conventional lattice unit cell has its corresponding reduced primitive unit cell. This study presents the frequency distribution of the reduced unit cells of all centred lattice entries of the Protein Data Bank (as of 23 August 2011) in four unit-cell-dimension-based groups and seven interaxial-angle-based subgroups. This frequency distribution is an added layer of support during space-group assignment in new crystals. In addition, some interesting patterns of distribution are discussed as well as how some reduced unit cells could be wrongly accepted as primitive lattices in a different crystal system.

  12. A New Quantum Key Distribution Scheme Based on Frequency and Time Coding

    International Nuclear Information System (INIS)

    Chang-Hua, Zhu; Chang-Xing, Pei; Dong-Xiao, Quan; Jing-Liang, Gao; Nan, Chen; Yun-Hui, Yi

    2010-01-01

    A new scheme of quantum key distribution (QKD) using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the central frequency or the time delay of the optical pulse at the sender. The central frequency of the single photon pulse is set as ω 1 for bit 0 and set as ω 2 for bit 1 when frequency coding is selected. However, the single photon pulse is not delayed for bit 0 and is delayed in τ for 1 when time coding is selected. At the receiver, either the frequency or the time delay of the pulse is measured randomly, and the final key is obtained after basis comparison, data reconciliation and privacy amplification. With the proposed method, the effect of the noise in the fiber channel and environment on the QKD system can be reduced effectively

  13. Inferring the flood frequency distribution for an ungauged basin using a spatially distributed rainfall-runoff model

    Directory of Open Access Journals (Sweden)

    G. Moretti

    2008-08-01

    Full Text Available The estimation of the peak river flow for ungauged river sections is a topical issue in applied hydrology. Spatially distributed rainfall-runoff models can be a useful tool to this end, since they are potentially able to simulate the river flow at any location of the watershed drainage network. However, it is not fully clear to what extent these models can provide reliable simulations over a wide range of spatial scales. This issue is investigated here by applying a spatially distributed, continuous simulation rainfall-runoff model to infer the flood frequency distribution of the Riarbero River. This is an ungauged mountain creek located in northern Italy, whose drainage area is 17 km2. The hydrological model is first calibrated by using a 1-year record of hourly meteorological data and river flows observed at the outlet of the 1294 km2 wide Secchia River basin, of which the Riarbero is a tributary. The model is then validated by performing a 100-year long simulation of synthetic river flow data, which allowed us to compare the simulated and observed flood frequency distributions at the Secchia River outlet and the internal cross river section of Cavola Bridge, where the basin area is 337 km2. Finally, another simulation of hourly river flows was performed by referring to the outlet of the Riarbero River, therefore allowing us to estimate the related flood frequency distribution. The results were validated by using estimates of peak river flow obtained by applying hydrological similarity principles and a regional method. The results show that the flood flow estimated through the application of the distributed model is consistent with the estimate provided by the regional procedure as well as the behaviors of the river banks. Conversely, the method based on hydrological similarity delivers an estimate that seems to be not as reliable. The analysis highlights interesting perspectives for the application of

  14. Ultra-stable long distance optical frequency distribution using the Internet fiber network.

    Science.gov (United States)

    Lopez, Olivier; Haboucha, Adil; Chanteau, Bruno; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Giorgio

    2012-10-08

    We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The stable frequency optical signal is processed enabling uninterrupted propagation on both directions. The robustness and the performance of the link are enhanced by a cost effective fully automated optoelectronic station. This device is able to coherently regenerate the return optical signal with a heterodyne optical phase locking of a low noise laser diode. Moreover the incoming signal polarization variation are tracked and processed in order to maintain beat note amplitudes within the operation range. Stable fibered optical interferometer enables optical detection of the link round trip phase signal. The phase-noise compensated link shows a fractional frequency instability in 10 Hz bandwidth of 5 × 10(-15) at one second measurement time and 2 × 10(-19) at 30,000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network.

  15. Application of Choi—Williams Reduced Interference Time Frequency Distribution to Machinery Diagnostics

    Directory of Open Access Journals (Sweden)

    Howard A. Gaberson

    1995-01-01

    Full Text Available This article discusses time frequency analysis of machinery diagnostic vibration signals. The short time Fourier transform, the Wigner, and the Choi–Williams distributions are explained and illustrated with test cases. Examples of Choi—Williams analyses of machinery vibration signals are presented. The analyses detect discontinuities in the signals and their timing, amplitude and frequency modulation, and the presence of different components in a vibration signal.

  16. Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

    OpenAIRE

    Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

    2015-01-01

    Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

  17. Finite Time Control for Fractional Order Nonlinear Hydroturbine Governing System via Frequency Distributed Model

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2016-01-01

    Full Text Available This paper studies the application of frequency distributed model for finite time control of a fractional order nonlinear hydroturbine governing system (HGS. Firstly, the mathematical model of HGS with external random disturbances is introduced. Secondly, a novel terminal sliding surface is proposed and its stability to origin is proved based on the frequency distributed model and Lyapunov stability theory. Furthermore, based on finite time stability and sliding mode control theory, a robust control law to ensure the occurrence of the sliding motion in a finite time is designed for stabilization of the fractional order HGS. Finally, simulation results show the effectiveness and robustness of the proposed scheme.

  18. Frequency distribution analysis of the long-lived beta-activity of air dust

    International Nuclear Information System (INIS)

    Bunzl, K.; Hoetzl, H.; Winkler, R.

    1977-01-01

    In order to compare the average annual beta activities of air dust a frequency distribution analysis of data has been carried out in order to select a representative quantity for the average value of the data group. It was found that the data to be analysed were consistent with a log-normal frequency distribution and therefore calculations were made of, as the representative average, the median of the beta activity of each year as the antilog of the arithmetric mean of the logarithms, log x, of the analytical values x. The 95% confidence limits were also obtained. The quantities thus calculated are summarized in tabular form. (U.K.)

  19. Dependence of exponents on text length versus finite-size scaling for word-frequency distributions

    Science.gov (United States)

    Corral, Álvaro; Font-Clos, Francesc

    2017-08-01

    Some authors have recently argued that a finite-size scaling law for the text-length dependence of word-frequency distributions cannot be conceptually valid. Here we give solid quantitative evidence for the validity of this scaling law, using both careful statistical tests and analytical arguments based on the generalized central-limit theorem applied to the moments of the distribution (and obtaining a novel derivation of Heaps' law as a by-product). We also find that the picture of word-frequency distributions with power-law exponents that decrease with text length [X. Yan and P. Minnhagen, Physica A 444, 828 (2016), 10.1016/j.physa.2015.10.082] does not stand with rigorous statistical analysis. Instead, we show that the distributions are perfectly described by power-law tails with stable exponents, whose values are close to 2, in agreement with the classical Zipf's law. Some misconceptions about scaling are also clarified.

  20. On the Frequency Distribution of Neutral Particles from Low-Energy Strong Interactions

    Directory of Open Access Journals (Sweden)

    Federico Colecchia

    2017-01-01

    Full Text Available The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a particle-level view of collision events, in line with recently proposed subtraction methods. While conventional techniques in the field usually concentrate on probability distributions, our study is, to our knowledge, the first attempt at estimating the frequency distribution of background particles across the kinematic space inside individual collision events. In fact, while the probability distribution can generally be estimated given a model of low-energy strong interactions, the corresponding frequency distribution inside a single event typically deviates from the average and cannot be predicted a priori. We present preliminary results in this direction and establish a connection between our technique and the particle weighting methods that have been the subject of recent investigation at the Large Hadron Collider.

  1. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Cain, O.; Gray, W.M.

    1977-01-01

    Cumulative Radiation Effect (CRE) represents a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Computer calculations have been used to simplify the evaluation of problems associated with the applications of the CRE-system in radiotherapy. In a general appraisal of the applications of computers to the CRE-system, the various problems encountered in clinical radiotherapy have been categorised into those involving the evaluation of a CRE at a point in tissue and those involving the calculation of CRE distributions. As a general guide, the computer techniques adopted at the Glasgow Institute of Radiotherapeutics for the solution of CRE problems are presented, and consist basically of a package of three interactive programs for point CRE calculations and a Fortran program which calculates CRE distributions for iso-effect treatment planning. Many examples are given to demonstrate the applications of these programs, and special emphasis has been laid on the problem of treating a point in tissue with different doses per fraction on alternate treatment days. The wide range of possible clinical applications of the CRE-system has been outlined and described under the categories of routine clinical applications, retrospective and prospective surveys of patient treatment, and experimental and theoretical research. Some of these applications such as the results of surveys and studies of time optimisation of treatment schedules could have far-reaching consequences and lead to significant improvements in treatment and cure rates with the minimum damage to normal tissue. (author)

  2. Study of the performance of collision short time approximation for neutron scattering using discrete frequency distribution

    International Nuclear Information System (INIS)

    D'Oliveira, A.B.; Amorim, E.S. do; Galvao, O.B.

    1981-03-01

    Double differential cross sections for thermal neutrons, based on incoherent approximation, using continum distribution as discrete frequency set are theoretically estimated, regarding two models previously done. The FASTT computer program is used in order to obtain a numerical estimation. (L.C.) [pt

  3. Vehicle-to-Grid Systems for Frequency Regulation in an Islanded Danish Distribution Network

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

    2010-01-01

    vehicles could provide power system ancillary services in the form of power balancing reserves to support the large-scale integration of variable renewable energy sources like wind power. This paper investigates the dynamic frequency response of an islanded Danish distribution system operation with large...

  4. Frequency of inhibitors of daphnid trypsin in the widely distributed cyanobacterial genus Planktothrix

    DEFF Research Database (Denmark)

    Rohrlack, T.; Christoffersen, K.; Friberg-Jensen, U.

    2005-01-01

    on the frequency of such compounds in the widely distributed cyanobacterial genus Planktothrix. Of the 89 Planktothrix strains analysed, about 70% produced inhibitors of daphnid trypsin. The strains tested positive represented three common Planktothrix species and were isolated from diverse localities...

  5. Frequency distribution of ABO and Rh (D) blood group alleles in ...

    African Journals Online (AJOL)

    Kassahun Tesfaye

    2014-09-22

    Sep 22, 2014 ... Rh (D). Abstract Background: Frequency distribution of blood groups is important as it is used in mod- ern medicine ... sion practice. The need for ... The study design was approved by the Research Ethics Com- mittee, College ...

  6. Real-Time Analysis of an Active Distribution Network - Coordinated Frequency Control for Islanding Operation

    DEFF Research Database (Denmark)

    Cha, Seung-Tae

    distribution networks makes it possible to operate the distribution networks independently which is called islanding operation. However, it is a challenge to ensure secure and reliable operation of the islanded system due to a num-ber of reasons, e.g. low inertia in the islanded system, intermittency of some...... of the DERs, etc. Particularly during islanding operation, with relatively few DG units, the frequency and voltage control of the islanded system is not straightforward. DG units, specially based on renewable energy sources (RESs), i.e. wind and solar, have an inter-mittent nature and intrinsic...... system (BESS) and two secondary frequency control scenarios with BESS and DG units. During the island-ing transition, the frequency is regulated by the fast-acting primary control of the BESS. The secondary control of the main management system (MMS) detects the status of the BESS and tries to return...

  7. Divergent Cumulative Cultural Evolution

    OpenAIRE

    Marriott, Chris; Chebib, Jobran

    2016-01-01

    Divergent cumulative cultural evolution occurs when the cultural evolutionary trajectory diverges from the biological evolutionary trajectory. We consider the conditions under which divergent cumulative cultural evolution can occur. We hypothesize that two conditions are necessary. First that genetic and cultural information are stored separately in the agent. Second cultural information must be transferred horizontally between agents of different generations. We implement a model with these ...

  8. Under-Frequency Load Shedding Technique Considering Event-Based for an Islanded Distribution Network

    Directory of Open Access Journals (Sweden)

    Hasmaini Mohamad

    2016-06-01

    Full Text Available One of the biggest challenge for an islanding operation is to sustain the frequency stability. A large power imbalance following islanding would cause under-frequency, hence an appropriate control is required to shed certain amount of load. The main objective of this research is to develop an adaptive under-frequency load shedding (UFLS technique for an islanding system. The technique is designed considering an event-based which includes the moment system is islanded and a tripping of any DG unit during islanding operation. A disturbance magnitude is calculated to determine the amount of load to be shed. The technique is modeled by using PSCAD simulation tool. A simulation studies on a distribution network with mini hydro generation is carried out to evaluate the UFLS model. It is performed under different load condition: peak and base load. Results show that the load shedding technique have successfully shed certain amount of load and stabilized the system frequency.

  9. Electron energy distributions and excitation rates in high-frequency argon discharges

    International Nuclear Information System (INIS)

    Ferreira, C.M.; Loureiro, J.

    1983-06-01

    The electron energy distribution functions and rate coefficients for excitation and ionisation in argon under the action of an uniform high-frequency electric field were calculated by numerically solving the homogeneous Boltzmann equation. Analytic calculations in the limiting cases ω>>νsub(c) and ω<<νsub(c), where ω is the wave angular frequency and νsub(c) is the electron-neutral collision frequency for momentum transfer, are also presented and shown to be in very good agreement with the numerical computations. The results reported here are relevant for the modelling of high-frequency discharges in argon and, in particular, for improving recent theoretical descriptions of a plasma column sustained by surface microwaves. The properties of surface wave produced plasmas make them interesting as possible substitutes for other more conventional plasma sources for such important applications as plasma chemistry laser excitation, plasma etching spectroscopic sources etc...

  10. Efficiency of the estimators of multivariate distribution parameters from the one-dimensional observed frequencies

    International Nuclear Information System (INIS)

    Chernov, N.I.; Kurbatov, V.S.; Ososkov, G.A.

    1988-01-01

    Parameter estimation for multivariate probability distributions is studied in experiments where data are presented as one-dimensional hystograms. For this model a statistics defined as a quadratic form of the observed frequencies which has a limitig x 2 -distribution is proposed. The efficiency of the estimator minimizing the value of that statistics is proved whithin the class of all unibased estimates obtained via minimization of quadratic forms of observed frequencies. The elaborated method was applied to the physical problem of analysis of the secondary pion energy distribution in the isobar model of pion-nucleon interactions with the production of an additional pion. The numerical experiments showed that the accuracy of estimation is twice as much if comparing the conventional methods

  11. The Gaussian atmospheric transport model and its sensitivity to the joint frequency distribution and parametric variability.

    Science.gov (United States)

    Hamby, D M

    2002-01-01

    Reconstructed meteorological data are often used in some form of long-term wind trajectory models for estimating the historical impacts of atmospheric emissions. Meteorological data for the straight-line Gaussian plume model are put into a joint frequency distribution, a three-dimensional array describing atmospheric wind direction, speed, and stability. Methods using the Gaussian model and joint frequency distribution inputs provide reasonable estimates of downwind concentration and have been shown to be accurate to within a factor of four. We have used multiple joint frequency distributions and probabilistic techniques to assess the Gaussian plume model and determine concentration-estimate uncertainty and model sensitivity. We examine the straight-line Gaussian model while calculating both sector-averaged and annual-averaged relative concentrations at various downwind distances. The sector-average concentration model was found to be most sensitive to wind speed, followed by horizontal dispersion (sigmaZ), the importance of which increases as stability increases. The Gaussian model is not sensitive to stack height uncertainty. Precision of the frequency data appears to be most important to meteorological inputs when calculations are made for near-field receptors, increasing as stack height increases.

  12. Spindle frequency activity in the sleep EEG: individual differences and topographic distribution.

    Science.gov (United States)

    Werth, E; Achermann, P; Dijk, D J; Borbély, A A

    1997-11-01

    The brain topography of EEG power spectra in the frequency range of sleep spindles was investigated in 34 sleep recordings from 20 healthy young men. Referential (F3-A2, C3-A2, P3-A2 and O1-A2) and bipolar derivations (F3-C3, C3-P3 and P3-O1) along the anteroposterior axis were used. Sleep spindles gave rise to a distinct peak in the EEG power spectrum. The distribution of the peak frequencies pooled over subjects and derivations showed a bimodal pattern with modes at 11.5 and 13.0 Hz, and a trough at 12.25 Hz. The large inter-subject variation in peak frequency (range: 1.25 Hz) contrasted with the small intra-subject variation between derivations, non-REM sleep episodes and different nights. In some individuals and/or some derivations, only a single spindle peak was present. The topographic distributions from referential and bipolar recordings showed differences. The power showed a declining trend over consecutive non-REM sleep episodes in the low range of spindle frequency activity and a rising trend in the high range. The functional and topographic heterogeneity of sleep spindles in conjunction with the intra-subject stability of their frequency are important characteristics for the analysis of sleep regulation on the basis of the EEG.

  13. Frequency distribution of Radium-226, Thorium-228 and Potassium-40 concentration in ploughed soils

    International Nuclear Information System (INIS)

    Drichko, V.F.; Krisyuk, B.E.; Travnikova, I.G.; Lisachenko, E.P.; Dubenskaya, M.A.

    1977-01-01

    The results of studying Ra-226, Th-228 and K-40 concentration distribution laws in podsol, chernozem and saline soils are considered. Radionuclide concentrations were determined by gamma-spectrometric method in the samples chosen from arable soil layer according to the generally accepted agrotechnical procedure. Measuring procedure is described. The results show that frequency distributions of radionuclide concentrations transform from asymmetric form in normal coordinates into symmetric form in logarithmic coordinates. The usage of the lognormal law to describe frequency concentration distributions is substantiated. The values of concentration distribution parameters are given. The analysis of the data obtained permits to establish that Ra-226 and Th-228 concentrations in soils distribute lognormally and K-40 concentrations - normally and lognormally. According to the degree of decreasing mean concentrations of Ra-226 and Th-228, soils lie in line: chernozems=chernozem salterns > podsols; and according to the degree of decreasing mean quadratic deviation - in line: podsols>chernozems=salterns. It is necessary to determine the value of mean quadratic deviation and distribution type for full characteristics of the studied soil radioactivity

  14. Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System

    Energy Technology Data Exchange (ETDEWEB)

    Randy Peden; Sanjiv Shah

    2005-07-26

    This report describes complete results of the project entitled ''Enhanced Recovery Utilizing Variable Frequency Drives and a Distributed Power System''. This demonstration project was initiated in July 2003 and completed in March 2005. The objective of the project was to develop an integrated power production/variable frequency drive system that could easily be deployed in the oil field that would increase production and decrease operating costs. This report describes all the activities occurred and documents results of the demonstration.

  15. Use of commercial vessels in survey augmentation: the size-frequency distribution

    Directory of Open Access Journals (Sweden)

    Eric N. Powell

    2006-09-01

    Full Text Available The trend towards use of commercial vessels to enhance survey data requires assessment of the advantages and limitations of various options for their use. One application is to augment information on size-frequency distributions obtained in multispecies trawl surveys where stratum boundaries and sampling density are not optimal for all species. Analysis focused on ten recreationally and commercially important species: bluefish, butterfish, Loligo squid, weakfish, summer flounder, winter flounder, silver hake (whiting, black sea bass, striped bass, and scup (porgy. The commercial vessel took 59 tows in the sampled domain south of Long Island, New York and the survey vessel 18. Black sea bass, Loligo squid, and summer flounder demonstrated an onshore-offshore gradient such that smaller fish were caught disproportionately inshore and larger fish offshore. Butterfish, silver hake, and weakfish were characterized by a southwest-northeast gradient such that larger fish were caught disproportionately northeast of the southwestern-most sector. All sizes of scup, striped bass, and bluefish were caught predominately inshore. Winter flounder were caught predominately offshore. The commercial vessel was characterized by an increased frequency of large catches for most species. Consequently, patchiness was assayed to be higher by the commercial vessel in nearly all cases. The size-frequency distribution obtained by the survey vessel for six of the ten species, bluefish, butterfish, Loligo squid, summer flounder, weakfish, and silver hake, could not be obtained by chance from the size-frequency distribution obtained by the commercial vessel. The difference in sample density did not significantly influence the size-frequency distribution. Of the six species characterized by significant differences in size-frequency distribution between boats, all but one was patchy at the population level and all had one or more size classes so characterized. Although the

  16. Maximum-likelihood methods for array processing based on time-frequency distributions

    Science.gov (United States)

    Zhang, Yimin; Mu, Weifeng; Amin, Moeness G.

    1999-11-01

    This paper proposes a novel time-frequency maximum likelihood (t-f ML) method for direction-of-arrival (DOA) estimation for non- stationary signals, and compares this method with conventional maximum likelihood DOA estimation techniques. Time-frequency distributions localize the signal power in the time-frequency domain, and as such enhance the effective SNR, leading to improved DOA estimation. The localization of signals with different t-f signatures permits the division of the time-frequency domain into smaller regions, each contains fewer signals than those incident on the array. The reduction of the number of signals within different time-frequency regions not only reduces the required number of sensors, but also decreases the computational load in multi- dimensional optimizations. Compared to the recently proposed time- frequency MUSIC (t-f MUSIC), the proposed t-f ML method can be applied in coherent environments, without the need to perform any type of preprocessing that is subject to both array geometry and array aperture.

  17. A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY

    International Nuclear Information System (INIS)

    Staples, J.W.; Byrd, J.; Doolittle, L.; Huang, G.; Wilcox, R.

    2008-01-01

    An optical fiber-based frequency and timing distribution system based on the principle of heterodyne interferometry has been in development at LBNL for several years. The fiber drift corrector has evolved from an RF-based to an optical-based system, from mechanical correctors (piezo and optical trombone) to fully electronic, and the electronics from analog to fully digital, all using inexpensive off-the-shelf commodity fiber components. Short-term optical phase jitter and long-term phase drift are both in the femtosecond range over distribution paths of 2 km or more

  18. Local time distribution of the SSC-associated HF-Doppler frequency shifts

    International Nuclear Information System (INIS)

    Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

    1985-01-01

    The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field

  19. Local time distribution of the SSC-associated HF-Doppler frequency shifts

    Science.gov (United States)

    Kikuchi, T.; Sugiuchi, H.; Ishimine, T.

    1985-01-01

    The HF-Doppler frequency shift observed at the storm's sudden commencement is composed of a frequency increase (+) and decrease (-), and classified into four types, SCF(+ -), SCF(- +), SCF(+) and SCF(-). Since the latter two types are special cases of the former two types, two different kinds of electrical field exist in the F region and cause the ExB drift motion of plasma. HUANG (1976) interpreted the frequency increase of SCF(+ -) as due to the westward induction electric field proportional to delta H/ delta t and the succeeding frequency decrease due to the eastward conduction electric field which produces ionospheric currents responsible for the magnetic increase on the ground. In spite of his success in interpreting the SCF(+ -), some other interpretations are needed for the explanation of the whole set of SCF's, particularly SCF(- +). Local time distributions of the SCF's are derived from 41 SCF's which are observed on the HF standard signal (JJY) as received in Okinawa (path length =1600 km) and Kokubunji (60 km). It is shown that the SCF(+ -) appears mainly during the day, whereas the SCF(- +) is observed during the night. The results indicate that the preliminary frequency shift (+) of SCF(+ -) and (-) of SCF(- +) is caused by a westward electric field in the dayside hemisphere, while by an eastward electric field in the nightside hemisphere. The main frequency shift (-) of SCF(+ -) and (+) of SCF(- +) is caused by the reversed electric field. Consequently, the preliminary frequency shift is caused by the dusk-to-dawn electric field, while the main frequency shift by the dawn-to-dusk electric field.

  20. Development of a distributed polarization-OTDR to measure two vibrations with the same frequency

    Science.gov (United States)

    Pan, Yun; Wang, Feng; Wang, Xiangchuan; Zhang, Mingjiang; Zhou, Ling; Sun, Zhenqing; Zhang, Xuping

    2015-08-01

    A polarization optical time-domain reflectometer (POTDR) can distributedly measure the vibration of fiber by detecting the vibration induced polarization variation only with a polarization analyzer. It has great potential in the monitoring of the border intrusion, structural healthy, anti-stealing of pipeline and so on, because of its simple configuration, fast response speed and distributed measuring ability. However, it is difficult to distinguish two vibrations with the same frequency for POTDR because the signal induced by the first vibration would bury the other vibration induced signal. This paper proposes a simple method to resolve this problem in POTDR by analyzing the phase of the vibration induced signal. The effectiveness of this method in distinguishing two vibrations with the same frequency for POTDR is proved by simulation.

  1. The Distribution and Frequency of the Terms "Pride" and "Prejudice" in Jane Austen's Pride and Prejudice

    Directory of Open Access Journals (Sweden)

    Tanja Dromnes

    2009-03-01

    Full Text Available In this article we examine the title terms of Jane Austen's Pride and Prejudice (1813 with particular attention to their distribution and frequency in the text. Our method is to connect the statistical material gathered on frequency and distribution to a narratological analysis of the terms, with special emphasis on whether they occur within the focalization of the external narrator, or that of character-focalizers. In order to approach this task, we have availed ourselves of the narratological theories of Mieke Bal. We conclude that there is a differentiation among types of focalization in the novel that enhances the thematic structure of match-making. Although Jane Austen wrote and published her major works two centuries ago, they continue to fascinate literary scholars and general readers alike.

  2. Features of the use of time-frequency distributions for controlling the mixture-producing aggregate

    Science.gov (United States)

    Fedosenkov, D. B.; Simikova, A. A.; Fedosenkov, B. A.

    2018-05-01

    The paper submits and argues the information on filtering properties of the mixing unit as a part of the mixture-producing aggregate. Relevant theoretical data concerning a channel transfer function of the mixing unit and multidimensional material flow signals are adduced here. Note that ordinary one-dimensional material flow signals are defined in terms of time-frequency distributions of Cohen’s class representations operating with Gabor wavelet functions. Two time-frequencies signal representations are written about in the paper to show how one can solve controlling problems as applied to mixture-producing systems: they are the so-called Rihaczek and Wigner-Ville distributions. In particular, the latter illustrates low-pass filtering properties that are practically available in any of low-pass elements of a physical system.

  3. Engineering Inertial and Primary-Frequency Response for Distributed Energy Resources: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Dall-Anese, Emiliano [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Guggilam, Swaroop [University of Minnesota; Dhople, Sairaj V [University of Minnesota; Chen, Yu C [University of British Columbia; Zhao, Changhong [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-12-19

    We propose a framework to engineer synthetic-inertia and droop-control parameters for distributed energy resources (DERs) so that the system frequency in a network composed of DERs and synchronous generators conforms to prescribed transient and steady-state performance specifications. Our approach is grounded in a second-order lumped-parameter model that captures the dynamics of synchronous generators and frequency-responsive DERs endowed with inertial and droop control. A key feature of this reduced-order model is that its parameters can be related to those of the originating higher-order dynamical model. This allows one to systematically design the DER inertial and droop-control coefficients leveraging classical frequency-domain response characteristics of second-order systems. Time-domain simulations validate the accuracy of the model-reduction method and demonstrate how DER controllers can be designed to meet steady-state-regulation and transient-performance specifications.

  4. A two-component generalized extreme value distribution for precipitation frequency analysis

    Czech Academy of Sciences Publication Activity Database

    Rulfová, Zuzana; Buishand, A.; Roth, M.; Kyselý, Jan

    2016-01-01

    Roč. 534, March (2016), s. 659-668 ISSN 0022-1694 R&D Projects: GA ČR(CZ) GA14-18675S Institutional support: RVO:68378289 Keywords : precipitation extremes * two-component extreme value distribution * regional frequency analysis * convective precipitation * stratiform precipitation * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.483, year: 2016 http://www.sciencedirect.com/science/article/pii/S0022169416000500

  5. Influence of chromosome territory morphology and nuclear distribution on exchange frequencies: comparison between experiment and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kreth, G.; Hase, J.V.; Finsterle, J.; Cremer, C. [Kirchhoff Institute for Physics, INF, Heidelber (Germany); Greulich, K. [German Cancer Research Center, INF, Heidelberg (Germany); Cremer, M. [Institute of Anthropology and Human Genetics, Muenchen (Germany)

    2003-07-01

    To explore the influence of chromosome territory morphology and the positioning of certain chromosomes in the nuclear volume on aberration frequencies, in the present study geometric computer models of all Chromosome Territories (CTs) in a human cell nucleus were used to investigate these constraints quantitatively. For this purpose a geometric representation of a CT in a given nuclear volume was approximated by a linear polymer chain of 500 nm sized spherical 1 Mbp domains connected by entropic spring potentials. The morphology aspect was investigated for the active and inactive X-chromosome of female cells. Assuming a statistical distribution of Xa, Xi and the autosomes a quite good agreement of virtually calculated translocation break frequencies with observed frequencies determined from Hiroshima A-bomb survivors was found. To regard in a first step the aspect of the experimentally observed different locations of certain chromosomes, a simulated gene density correlated distribution of modeled lymphocytes was realized. The respective calculated translocation frequencies were compared with fish experiments of irradiated lymphocyte cells. (author)

  6. Spectral Energy Distribution and Radio Halo of NGC 253 at Low Radio Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Kapińska, A. D.; Staveley-Smith, L.; Meurer, G. R.; For, B.-Q. [International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Hwy, WA 6009 (Australia); Crocker, R. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Bhandari, S.; Callingham, J. R.; Gaensler, B. M.; Hancock, P. J.; Lenc, E. [ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), Sydney NSW (Australia); Hurley-Walker, N.; Seymour, N. [International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia); Offringa, A. R. [Netherlands Institute for Radio Astronomy (ASTRON), P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Hanish, D. J. [Spitzer Science Center, California Institute of Technology, MC 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Ekers, R. D.; Bell, M. E. [CSIRO Astronomy and Space Science (CASS), P.O. Box 76, Epping, NSW 1710 (Australia); Dwarakanath, K. S. [Raman Research Institute, Bangalore 560080 (India); Hindson, L. [Centre of Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140 (New Zealand); McKinley, B., E-mail: anna.kapinska@uwa.edu.au [School of Physics, The University of Melbourne, Parkville, VIC 3010 (Australia); and others

    2017-03-20

    We present new radio continuum observations of NGC 253 from the Murchison Widefield Array at frequencies between 76 and 227 MHz. We model the broadband radio spectral energy distribution for the total flux density of NGC 253 between 76 MHz and 11 GHz. The spectrum is best described as a sum of a central starburst and extended emission. The central component, corresponding to the inner 500 pc of the starburst region of the galaxy, is best modeled as an internally free–free absorbed synchrotron plasma, with a turnover frequency around 230 MHz. The extended emission component of the spectrum of NGC 253 is best described as a synchrotron emission flattening at low radio frequencies. We find that 34% of the extended emission (outside the central starburst region) at 1 GHz becomes partially absorbed at low radio frequencies. Most of this flattening occurs in the western region of the southeast halo, and may be indicative of synchrotron self-absorption of shock-reaccelerated electrons or an intrinsic low-energy cutoff of the electron distribution. Furthermore, we detect the large-scale synchrotron radio halo of NGC 253 in our radio images. At 154–231 MHz the halo displays the well known X-shaped/horn-like structure, and extends out to ∼8 kpc in the z -direction (from the major axis).

  7. Distribution of Argon Arc Contaminated with Nitrogen as Function of Frequency in Pulsed TIG Welding

    Science.gov (United States)

    Takahashi, Hiroki; Tanaka, Tatsuro; Yamamoto, Shinji; Iwao, Toru

    2016-09-01

    TIG arc welding is the high-quality and much applicable material joining technology. However, the current has to be small because the cathode melting should be prevented. In this case, the heat input to the welding pool becomes low, then, the welding defect sometimes occurs. The pulsed TIG arc welding is used to improve this disadvantage This welding can be controlled by some current parameters such as frequency However, few report has reported the distribution of argon arc contaminated with nitrogen It is important to prevent the contamination of nitrogen because the melting depth increases in order to prevent the welding defects. In this paper, the distribution of argon arc contaminated as function of frequency with nitrogen in pulsed TIG welding is elucidated. The nitrogen concentration, the radial flow velocity, the arc temperature were calculated using the EMTF simulation when the time reached at the base current. As a result, the nitrogen concentration into the arc became low with increasing the frequency The diffusion coefficient decreased because of the decrement of temperature over 4000 K. In this case, the nitrogen concentration became low near the anode. Therefore, the nitrogen concentration became low because the frequency is high.

  8. Frequency and distribution analysis of chromosomal translocations induced by x-ray in human lymphocytes

    International Nuclear Information System (INIS)

    Lopez Hidalgo, Juana Ines

    2000-01-01

    The characteristic of ionizing radiation suggests that induced chromosomal damage in the form of translocations would appear to be randomly distributed. However, the outcome of tests performed in vitro and in vivo (irradiated individuals) are contradictories. The most translocation-related chromosomes, as far as some studies reveal on one hand, appear to be less involved in accordance with others. These data, together with those related to molecular mechanisms involved in translocations production suggest that in G 0 -irradiated cells, the frequency and distribution of this kind of chromosomal rearrangement, does not take place at random. They seem to be affected by in-nucleus chromosome distribution, by each chromosome's DNA length and functional features, by the efficiency of DNA repair mechanisms, and by inter individual differences. The objective of this study was to establish the frequency pattern of each human chromosome involved in radio-induced translocations, as well as to analyze the importance the chromosome length, the activity of DNA polymerase- dependant repair mechanisms, and inter individual differences within the scope of such distribution. To achieve the goals, peripheral blood lymphocytes from healthy donors were irradiated in presence and absence of 2'-3' dideoxithimidine (ddThd), a Β - DNA polymerase inhibitor, which takes part in the base repair mechanism (B E R). The results showed that: The presence of ddThd during the irradiation increase the basal frequency of radioinduced translocations in 60 %. This result suggests that ddThd repair synthesis inhibition can be in itself a valid methodology for radiation-induced bases damage assessment, damage which if not BER-repaired may result in translocation-leading double strand breaks. A statistically significant correlation between translocation frequency and chromosome length, in terms of percentage of genome, has been noticed both in (basal) irradiation and in irradiation with ddThd inhibitor

  9. Oxide vapor distribution from a high-frequency sweep e-beam system

    Science.gov (United States)

    Chow, R.; Tassano, P. L.; Tsujimoto, N.

    1995-03-01

    Oxide vapor distributions have been determined as a function of operating parameters of a high frequency sweep e-beam source combined with a programmable sweep controller. We will show which parameters are significant, the parameters that yield the broadest oxide deposition distribution, and the procedure used to arrive at these conclusions. A design-of-experimental strategy was used with five operating parameters: evaporation rate, sweep speed, sweep pattern (pre-programmed), phase speed (azimuthal rotation of the pattern), profile (dwell time as a function of radial position). A design was chosen that would show which of the parameters and parameter pairs have a statistically significant effect on the vapor distribution. Witness flats were placed symmetrically across a 25 inches diameter platen. The stationary platen was centered 24 inches above the e-gun crucible. An oxide material was evaporated under 27 different conditions. Thickness measurements were made with a stylus profilometer. The information will enable users of the high frequency e-gun systems to optimally locate the source in a vacuum system and understand which parameters have a major effect on the vapor distribution.

  10. Body size diversity and frequency distributions of Neotropical cichlid fishes (Cichliformes: Cichlidae: Cichlinae.

    Directory of Open Access Journals (Sweden)

    Sarah E Steele

    Full Text Available Body size is an important correlate of life history, ecology and distribution of species. Despite this, very little is known about body size evolution in fishes, particularly freshwater fishes of the Neotropics where species and body size diversity are relatively high. Phylogenetic history and body size data were used to explore body size frequency distributions in Neotropical cichlids, a broadly distributed and ecologically diverse group of fishes that is highly representative of body size diversity in Neotropical freshwater fishes. We test for divergence, phylogenetic autocorrelation and among-clade partitioning of body size space. Neotropical cichlids show low phylogenetic autocorrelation and divergence within and among taxonomic levels. Three distinct regions of body size space were identified from body size frequency distributions at various taxonomic levels corresponding to subclades of the most diverse tribe, Geophagini. These regions suggest that lineages may be evolving towards particular size optima that may be tied to specific ecological roles. The diversification of Geophagini appears to constrain the evolution of body size among other Neotropical cichlid lineages; non-Geophagini clades show lower species-richness in body size regions shared with Geophagini. Neotropical cichlid genera show less divergence and extreme body size than expected within and among tribes. Body size divergence among species may instead be present or linked to ecology at the community assembly scale.

  11. ABO and Rh (D group distribution and gene frequency; the first multicentric study in India

    Directory of Open Access Journals (Sweden)

    Amit Agrawal

    2014-01-01

    Full Text Available Background and Objectives: The study was undertaken with the objective to provide data on the ABO and Rh(D blood group distribution and gene frequency across India. Materials and Methods: A total of 10,000 healthy blood donors donating in blood banks situated in five different geographical regions of the country (North, South, East and Center were included in the study. ABO and Rh (D grouping was performed on all these samples. Data on the frequency of ABO and Rh(D blood groups was reported in simple numbers and percentages. Results: The study showed that O was the most common blood group (37.12% in the country closely followed by B at 32.26%, followed by A at 22.88% while AB was the least prevalent group at 7.74%. 94.61% of the donor population was Rh positive and the rest were Rh negative. Regional variations were observed in the distribution. Using the maximum likelihood method, the frequencies of the I A , I B and I O alleles were calculated and tested according to the Hardy Weinberg law of Equilibrium. The calculated gene frequencies are 0.1653 for I A (p, 0.2254 for I B (q and 0.6093 for I O (r. In Indian Population, O (r records the highest value followed by B (q and A (p; O > B > A. Conclusion: The study provides information about the relative distribution of various alleles in the Indian population both on a pan-India basis as well as region-wise. This vital information may be helpful in planning for future health challenges, particularly planning with regards to blood transfusion services.

  12. An analysis of the temperature distribution in the pipe bending using high frequency induction heating

    International Nuclear Information System (INIS)

    Fukue, Hisayoshi; Mochizuki, Yoji; Nakamura, Harushige; Kobo, Hiroshi; Nitta, Tetsuo; Kawakami, Kiyoshi

    1986-01-01

    A pipe bending apparatus has recently been developed by applying high frequency induction heating. However, the smaller the radius of pipe bending, the greater becomes the reduction in wall thickness and the ovality of the pipe form. This makes it impossible to manufacture pipe bending which will meet the nuclear pipe design code. In order to solve this problem it is crucial to obtain a temperature distributions in a pipe which is moving. It is calculated by giving the following boundary conditions : distribution of the heat generation rate, and that of heat transfer of cooling water. In the process of analyzing these distributions, the following results were obtained. (1) The distribution of the heat generation rate is determined by the sink of energy flux of Poynting vectors. The coil efficiency thus calculated was sixty percent. This figure accords with the test data. (2) The distribution of heat transfer coefficient of cooling water is mainly determined by the rate of liquid film heat transfer, but departure from nucleate boiling and dryout has to be taken into consideration. (3) TRUMP CODE is modified so that the temperature distribution in moving pipes can be calculated by taking the boundary conditions into account. The calculated results were in accordance with the test data. (author)

  13. Cumulative human impacts on marine predators.

    Science.gov (United States)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J; Halpern, Benjamin S; Breed, Greg A; Nickel, Barry; Teutschel, Nicole M; Crowder, Larry B; Benson, Scott; Dutton, Peter H; Bailey, Helen; Kappes, Michelle A; Kuhn, Carey E; Weise, Michael J; Mate, Bruce; Shaffer, Scott A; Hassrick, Jason L; Henry, Robert W; Irvine, Ladd; McDonald, Birgitte I; Robinson, Patrick W; Block, Barbara A; Costa, Daniel P

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact (CUI) on marine predators by combining electronic tracking data of eight protected predator species (n=685 individuals) in the California Current Ecosystem with data on 24 anthropogenic stressors. We show significant variation in CUI with some of the highest impacts within US National Marine Sanctuaries. High variation in underlying species and cumulative impact distributions means that neither alone is sufficient for effective spatial management. Instead, comprehensive management approaches accounting for both cumulative human impacts and trade-offs among multiple stressors must be applied in planning the use of marine resources.

  14. Letting the (energy) Gini out of the bottle: Lorenz curves of cumulative electricity consumption and Gini coefficients as metrics of energy distribution and equity

    International Nuclear Information System (INIS)

    Jacobson, Arne; Milman, Anita D.; Kammen, Daniel M.

    2005-01-01

    Energy services are fundamental determinants of the quality of life as well as the economic vitality of both industrialized and developing nations. Few analytic tools exist, however, to explore changes in individual, household, and national levels of energy consumption and utilization. In order to contribute to such analyses, we extend the application of Lorenz curves to energy consumption. We examined the distribution of residential electricity consumption in five countries: Norway, USA, El Salvador, Thailand, and Kenya. These countries exhibit a dramatic range of energy profiles, with electricity consumption far more evenly distributed across the population in some industrialized nations than others, and with further significant differences in the Lorenz distribution between industrialized and industrializing economies. The metric also provides critical insights into the temporal evolution of energy management in different states and nations. We illustrate this with a preliminary longitudinal study of commercial and industrial electricity use in California during the economically volatile 1990s. Finally, we explore the limits of Lorenz analyses for understanding energy equity through a discussion of the roles that variations in energy conversion efficiency and climate play in shaping distributions of energy consumption. The Lorenz method, which is widely employed by economists to analyze income distribution, is largely unused in energy analysis, but provides a powerful new tool for estimating the distributional dimensions of energy consumption. Its widespread use can make significant contributions to scientific and policy debates about energy equity in the context of climate change mitigation, electric power industry deregulation and restructuring, and the development of national infrastructure

  15. Research on Distributed PV Storage Virtual Synchronous Generator System and Its Static Frequency Characteristic Analysis

    Directory of Open Access Journals (Sweden)

    Xiangwu Yan

    2018-03-01

    Full Text Available The increasing penetration rate of grid connected renewable energy power generation reduces the primary frequency regulation capability of the system and poses a challenge to the security and stability of the power grid. In this paper, a distributed photovoltaic (PV storage virtual synchronous generator system is constructed, which realizes the external characteristics of synchronous generator/motor. For this kind of input/output bidirectional devices (e.g., renewable power generation/storage combined systems, pumped storage power stations, battery energy storage systems, and vehicle-to-grid electric vehicles, a synthesis analysis method for system power-frequency considering source-load static frequency characteristics (S-L analysis method is proposed in order to depict the system’s power balance dynamic adjustment process visually. Simultaneously, an inertia matching method is proposed to solve the problem of inertia matching in the power grid. Through the simulation experiment in MATLAB, the feasibility of the distributed PV storage synchronous virtual machine system is verified as well as the effectiveness of S-L analysis method and inertia matching method.

  16. Blind Separation of Nonstationary Sources Based on Spatial Time-Frequency Distributions

    Directory of Open Access Journals (Sweden)

    Zhang Yimin

    2006-01-01

    Full Text Available Blind source separation (BSS based on spatial time-frequency distributions (STFDs provides improved performance over blind source separation methods based on second-order statistics, when dealing with signals that are localized in the time-frequency (t-f domain. In this paper, we propose the use of STFD matrices for both whitening and recovery of the mixing matrix, which are two stages commonly required in many BSS methods, to provide robust BSS performance to noise. In addition, a simple method is proposed to select the auto- and cross-term regions of time-frequency distribution (TFD. To further improve the BSS performance, t-f grouping techniques are introduced to reduce the number of signals under consideration, and to allow the receiver array to separate more sources than the number of array sensors, provided that the sources have disjoint t-f signatures. With the use of one or more techniques proposed in this paper, improved performance of blind separation of nonstationary signals can be achieved.

  17. Real-time updating of the flood frequency distribution through data assimilation

    Science.gov (United States)

    Aguilar, Cristina; Montanari, Alberto; Polo, María-José

    2017-07-01

    We explore the memory properties of catchments for predicting the likelihood of floods based on observations of average flows in pre-flood seasons. Our approach assumes that flood formation is driven by the superimposition of short- and long-term perturbations. The former is given by the short-term meteorological forcing leading to infiltration and/or saturation excess, while the latter is originated by higher-than-usual storage in the catchment. To exploit the above sensitivity to long-term perturbations, a meta-Gaussian model and a data assimilation approach are implemented for updating the flood frequency distribution a season in advance. Accordingly, the peak flow in the flood season is predicted in probabilistic terms by exploiting its dependence on the average flow in the antecedent seasons. We focus on the Po River at Pontelagoscuro and the Danube River at Bratislava. We found that the shape of the flood frequency distribution is noticeably impacted by higher-than-usual flows occurring up to several months earlier. The proposed technique may allow one to reduce the uncertainty associated with the estimation of flood frequency.

  18. Frequency distribution of gastro esophageal reflux disease in inhalation injury: A historical cohort study.

    Science.gov (United States)

    Karbasi, Ashraf; Aliannejad, Rasoul; Ghanei, Mostafa; Sanamy, Mehran Noory; Alaeddini, Farshid; Harandi, Ali Amini

    2015-07-01

    There is no data on the prevalence and the association of gastro esophageal reflux disease (GERD) with toxic fume inhalation. Therefore, we aimed to evaluate the frequency distribution of GERD symptoms among the individuals with mild respiratory disorder due to the past history of toxic fume exposure to sulfur mustard (SM). In a historical cohort study, subjects were randomly selected from 7000 patients in a database of all those who had a history of previous exposure to a single high dose of SM gas during war. The control group was randomly selected from adjacent neighbors of the patients, and two healthy male subjects were chosen per patient. In this study, we used the validated Persian translation of Mayo Gastroesophageal Reflux Questionnaire to assess the frequency distribution of reflux disease. Relative frequency of GERD symptoms, was found to be significantly higher in the inhalation injury patients with an odds ratio of 8.30 (95% confidence interval [CI]: 4.73-14.55), and after adjustment for cigarette smoking, tea consumption, age, and body mass index, aspirin and chronic cough the odds ratio was found to be 4.41 (95% CI: 1.61-12.07). The most important finding of our study was the major GERD symptoms (heartburn and/or acid regurgitation once or more per week) among the individuals with the past history of exposure to SM toxic gas is substantially higher (4.4-fold) than normal populations.

  19. Altered Frequency Distribution in the Electroencephalogram is Correlated to the Analgesic Effect of Remifentanil

    DEFF Research Database (Denmark)

    Graversen, Carina; Malver, Lasse P; Kurita, Geana P

    2015-01-01

    Opioids alter resting state brain oscillations by multiple and complex factors, which are still to be elucidated. To increase our knowledge, multi-channel electroencephalography (EEG) was subjected to multivariate pattern analysis (MVPA), to identify the most descriptive frequency bands and scalp...... distributions were extracted by a continuous wavelet transform and normalized into delta, theta, alpha, beta and gamma bands. Alterations relative to pre-treatment responses were calculated for all channels and used as input to the MVPA. Compared to placebo, remifentanil increased the delta band and decreased...... the theta and alpha band oscillations as a mean over all channels (all p ≤ 0.007). The most discriminative channels in these frequency bands were F1 in delta (83.33%, p = 0.0023) and theta bands (95.24%, p band (80.95%, p = 0.0054). These alterations were correlated...

  20. A modular multiple use system for precise time and frequency measurement and distribution

    Science.gov (United States)

    Reinhardt, V. S.; Adams, W. S.; Lee, G. M.; Bush, R. L.

    1978-01-01

    A modular CAMAC based system is described which was developed to meet a variety of precise time and frequency measurement and distribution needs. The system was based on a generalization of the dual mixer concept. By using a 16 channel 100 ns event clock, the system can intercompare the phase of 16 frequency standards with subpicosecond resolution. The system has a noise floor of 26 fs and a long term stability on the order of 1 ps or better. The system also used a digitally controlled crystal oscillator in a control loop to provide an offsettable 5 MHz output with subpicosecond phase tracking capability. A detailed description of the system is given including theory of operation and performance. A method to improve the performance of the dual mixer technique is discussed when phase balancing of the two input ports cannot be accomplished.

  1. Single-frequency thulium-doped distributed-feedback fibre laser

    DEFF Research Database (Denmark)

    Agger, Søren; Povlsen, Jørn Hedegaard; Varming, Poul

    2004-01-01

    We have successfully demonstrated a single-frequency distributed-feedback (DFB) thulium-doped silica fiber laser emitting at a wavelength of 1735 nm. The laser cavity is less than 5 cm long and is formed by intracore UV-written Bragg gratings with a phase shift. The laser is pumped at 790 nm from...... a Ti:sapphire laser and has a threshold pump power of 59 mW. The laser has a maximum output power of 1 mW in a singlefrequency, single-polarization radiation mode and is tunable over a few nanometers. To the best of the authors’ knowledge, this is the first report of a single-frequency DFB fiber laser...... that uses thulium as the amplifying medium. The lasing wavelength is the longest demonstrated with DFB fiber lasers and yet is among the shortest obtained for thulium-doped silica fiber lasers....

  2. Sampling frequency of ciliated protozoan microfauna for seasonal distribution research in marine ecosystems.

    Science.gov (United States)

    Xu, Henglong; Yong, Jiang; Xu, Guangjian

    2015-12-30

    Sampling frequency is important to obtain sufficient information for temporal research of microfauna. To determine an optimal strategy for exploring the seasonal variation in ciliated protozoa, a dataset from the Yellow Sea, northern China was studied. Samples were collected with 24 (biweekly), 12 (monthly), 8 (bimonthly per season) and 4 (seasonally) sampling events. Compared to the 24 samplings (100%), the 12-, 8- and 4-samplings recovered 94%, 94%, and 78% of the total species, respectively. To reveal the seasonal distribution, the 8-sampling regime may result in >75% information of the seasonal variance, while the traditional 4-sampling may only explain sampling frequency, the biotic data showed stronger correlations with seasonal variables (e.g., temperature, salinity) in combination with nutrients. It is suggested that the 8-sampling events per year may be an optimal sampling strategy for ciliated protozoan seasonal research in marine ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. All-Optical Frequency Modulated High Pressure MEMS Sensor for Remote and Distributed Sensing

    DEFF Research Database (Denmark)

    Reck, Kasper; Thomsen, Erik Vilain; Hansen, Ole

    2011-01-01

    We present the design, fabrication and characterization of a new all-optical frequency modulated pressure sensor. Using the tangential strain in a circular membrane, a waveguide with an integrated nanoscale Bragg grating is strained longitudinally proportional to the applied pressure causing...... a shift in the Bragg wavelength. The simple and robust design combined with the small chip area of 1 × 1.8 mm2 makes the sensor ideally suited for remote and distributed sensing in harsh environments and where miniaturized sensors are required. The sensor is designed for high pressure applications up...

  4. Robust Distributed Model Predictive Load Frequency Control of Interconnected Power System

    Directory of Open Access Journals (Sweden)

    Xiangjie Liu

    2013-01-01

    Full Text Available Considering the load frequency control (LFC of large-scale power system, a robust distributed model predictive control (RDMPC is presented. The system uncertainty according to power system parameter variation alone with the generation rate constraints (GRC is included in the synthesis procedure. The entire power system is composed of several control areas, and the problem is formulated as convex optimization problem with linear matrix inequalities (LMI that can be solved efficiently. It minimizes an upper bound on a robust performance objective for each subsystem. Simulation results show good dynamic response and robustness in the presence of power system dynamic uncertainties.

  5. Low noise buffer amplifiers and buffered phase comparators for precise time and frequency measurement and distribution

    Science.gov (United States)

    Eichinger, R. A.; Dachel, P.; Miller, W. H.; Ingold, J. S.

    1982-01-01

    Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators were developed. These buffer amplifiers are designed to distribute reference frequencies from 30 KHz to 45 MHz from a hydrogen maser without degrading the hydrogen maser's performance. The buffered phase comparators are designed to intercompare the phase of state of the art hydrogen masers without adding any significant measurement system noise. These devices have a 27 femtosecond phase stability floor and are stable to better than one picosecond for long periods of time. Their temperature coefficient is less than one picosecond per degree C, and they have shown virtually no voltage coefficients.

  6. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea

    KAUST Repository

    Lozano-Cortes, Diego

    2015-10-29

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north–south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea.

  7. Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review.

    Science.gov (United States)

    Ding, Zhenyang; Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

    2018-04-03

    Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

  8. Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

    Science.gov (United States)

    Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

    2018-01-01

    Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on. PMID:29614024

  9. Distributed strain measurement in perfluorinated polymer optical fibres using optical frequency domain reflectometry

    International Nuclear Information System (INIS)

    Liehr, Sascha; Wendt, Mario; Krebber, Katerina

    2010-01-01

    We present the latest advances in distributed strain measurement in perfluorinated polymer optical fibres (POFs) using backscatter techniques. Compared to previously introduced poly(methyl methacrylate) POFs, the measurement length can be extended to more than 500 m at improved spatial resolution of a few centimetres. It is shown that strain in a perfluorinated POF can be measured up to 100%. In parallel to these investigations, the incoherent optical frequency domain reflectometry (OFDR) technique is introduced to detect strained fibre sections and to measure distributed length change along the fibre with sub-millimetre resolution by applying a cross-correlation algorithm to the backscatter signal. The overall superior performance of the OFDR technique compared to the optical time domain reflectometry in terms of accuracy, dynamic range, spatial resolution and measurement speed is presented. The proposed sensor system is a promising technique for use in structural health monitoring applications where the precise detection of high strain is required

  10. Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

    Directory of Open Access Journals (Sweden)

    Zhenyang Ding

    2018-04-01

    Full Text Available Distributed optical fiber sensors (DOFS offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

  11. Higher moments method for generalized Pareto distribution in flood frequency analysis

    Science.gov (United States)

    Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

    2017-08-01

    The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

  12. Coordinated control of distributed energy resources to support load frequency control

    International Nuclear Information System (INIS)

    Ravikumar Pandi, V.; Al-Hinai, A.; Feliachi, Ali

    2015-01-01

    Highlights: • We aims to maintain feeder power flow by the coordination of DER units. • The error in feeder flow with respect to scheduled value is used by the controller. • The particle swarm optimization is employed to minimize the error in feeder flow. • Implemented on a transmission system along with 37 bus distribution feeder. • The results of proposed feeder control is analyzed with no feeder control scheme. - Abstract: The control of generating resources to follow the unscheduled load changes is considered to be an essential process in the power system in order to maintain the frequency of power supply. This load frequency control (LFC) problem has been given more importance in the recent smart grid environment because of the impact from high penetration of distributed energy resources (DER) installed at the distribution level. The renewable sources are highly intermittent in nature, so it is required to coordinate and control the DER units to maintain the feeder power flow at substation bus bar which is seen by transmission system operator during the LFC process. This paper aims to identify the impact of distributed generation and its control method to reduce the deviation of feeder power flow from the scheduled value in real time operation. The error in feeder power flow with respect to scheduled value is utilized by the PI controller to estimate the change in power reference of all DER units. The power output of DER units are maintained to reference values by the individual PI controllers. The particle swarm optimization algorithm is employed to minimize the error in feeder power flow by optimally tuning the gain values of all PI controllers. The proposed method is examined on a small transmission system along with the feeder of IEEE 37 bus distribution system with balanced loading condition. The complete system along with DER units is implemented in the MATLAB based stability package named Power Analysis Toolbox (PAT) for performing time domain

  13. Towards a systematic approach to comparing distributions used in flood frequency analysis

    Science.gov (United States)

    Bobée, B.; Cavadias, G.; Ashkar, F.; Bernier, J.; Rasmussen, P.

    1993-02-01

    The estimation of flood quantiles from available streamflow records has been a topic of extensive research in this century. However, the large number of distributions and estimation methods proposed in the scientific literature has led to a state of confusion, and a gap prevails between theory and practice. This concerns both at-site and regional flood frequency estimation. To facilitate the work of "hydrologists, designers of hydraulic structures, irrigation engineers and planners of water resources", the World Meteorological Organization recently published a report which surveys and compares current methodologies, and recommends a number of statistical distributions and estimation procedures. This report is an important step towards the clarification of this difficult topic, but we think that it does not effectively satisfy the needs of practitioners as intended, because it contains some statements which are not statistically justified and which require further discussion. In the present paper we review commonly used procedures for flood frequency estimation, point out some of the reasons for the present state of confusion concerning the advantages and disadvantages of the various methods, and propose the broad lines of a possible comparison strategy. We recommend that the results of such comparisons be discussed in an international forum of experts, with the purpose of attaining a more coherent and broadly accepted strategy for estimating floods.

  14. Crossover distribution and frequency are regulated by him-5 in Caenorhabditis elegans.

    Science.gov (United States)

    Meneely, Philip M; McGovern, Olivia L; Heinis, Frazer I; Yanowitz, Judith L

    2012-04-01

    Mutations in the him-5 gene in Caenorhabditis elegans strongly reduce the frequency of crossovers on the X chromosome, with lesser effects on the autosomes. him-5 mutants also show a change in crossover distribution on both the X and autosomes. These phenotypes are accompanied by a delayed entry into pachytene and premature desynapsis of the X chromosome. The nondisjunction, progression defects and desynapsis can be rescued by an exogenous source of double strand breaks (DSBs), indicating that the role of HIM-5 is to promote the formation of meiotic DSBs. Molecular cloning of the gene shows that the inferred HIM-5 product is a highly basic protein of 252 amino acids with no clear orthologs in other species, including other Caenorhabditis species. Although him-5 mutants are defective in segregation of the X chromosome, HIM-5 protein localizes preferentially to the autosomes. The mutant phenotypes and localization of him-5 are similar but not identical to the results seen with xnd-1, although unlike xnd-1, him-5 has no apparent effect on the acetylation of histone H2A on lysine 5 (H2AacK5). The localization of HIM-5 to the autosomes depends on the activities of both xnd-1 and him-17 allowing us to begin to establish pathways for the control of crossover distribution and frequency.

  15. Theoretical and experimental investigation into structural and fluid motions at low frequencies in water distribution pipes

    Science.gov (United States)

    Gao, Yan; Liu, Yuyou

    2017-06-01

    Vibrational energy is transmitted in buried fluid-filled pipes in a variety of wave types. Axisymmetric (n = 0) waves are of practical interest in the application of acoustic techniques for the detection of leaks in underground pipelines. At low frequencies n = 0 waves propagate longitudinally as fluid-dominated (s = 1) and shell-dominated (s = 2) waves. Whilst sensors such as hydrophones and accelerometers are commonly used to detect leaks in water distribution pipes, the mechanism governing the structural and fluid motions is not well documented. In this paper, the low-frequency behaviour of the pipe wall and the contained fluid is investigated. For most practical pipework systems, these two waves are strongly coupled; in this circumstance the ratios of the radial pipe wall displacements along with the internal pressures associated with these two wave types are obtained. Numerical examples show the relative insensitivity of the structural and fluid motions to the s = 2 wave for both metallic and plastic pipes buried in two typical soils. It is also demonstrated that although both acoustic and vibration sensors at the same location provide the identical phase information of the transmitted signals, pressure responses have significantly higher levels than acceleration responses, and thus hydrophones are better suited in a low signal-to-noise ratio (SNR) environment. This is supported by experimental work carried out at a leak detection facility. Additional pressure measurements involved excitation of the fluid and the pipe fitting (hydrant) on a dedicated water pipe. This work demonstrates that the s = 1 wave is mainly responsible for the structural and fluid motions at low frequencies in water distribution pipes as a result of water leakage and direct pipe excitation.

  16. Cumulation of light nuclei

    International Nuclear Information System (INIS)

    Baldin, A.M.; Bondarev, V.K.; Golovanov, L.B.

    1977-01-01

    Limit fragmentation of light nuclei (deuterium, helium) bombarded with 8,6 GeV/c protons was investigated. Fragments (pions, protons and deuterons) were detected within the emission angle 50-150 deg with regard to primary protons and within the pulse range 150-180 MeV/c. By the kinematics of collision of a primary proton with a target at rest the fragments observed correspond to a target mass upto 3 GeV. Thus, the data obtained correspond to teh cumulation upto the third order

  17. Analyses of Rock Size-Frequency Distributions and Morphometry of Modified Hawaiian Lava Flows: Implications for Future Martian Landing Sites

    Science.gov (United States)

    Craddock, Robert A.; Golombek, Matthew; Howard, Alan D.

    2000-01-01

    Both the size-frequency distribution and morphometry of rock populations emplaced by a variety of geologic processes in Hawaii indicate that such information may be useful in planning future landing sites on Mars and interpreting the surface geology.

  18. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea

    KAUST Repository

    Lozano-Corté s, Diego; Berumen, Michael L.

    2015-01-01

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central

  19. NODC Standard Product: International ocean atlas Volume 4 - Atlas of temperature / salinity frequency distributions (2 disc set) (NCEI Accession 0101473)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Atlas presents more than 80,000 plots of the empirical frequency distributions of temperature and salinity for each 5-degree square area of the North Atlantic...

  20. Impact of protection settings of the distributed generation frequency under 1MW in the national electric system

    International Nuclear Information System (INIS)

    Alpizar Chavarria, Oscar

    2013-01-01

    A literature review is conducted to understand the distributed generation, the reason for the introduction into modern power systems and other distributed generation technologies based on renewable energies that have been installed around the country. The frequency protections of distributed generation equipment under 1MW are studied according to international standards like IEEE-1547 and specifications of equipment manufacturers. The influence of the recommended international standards settings are investigated for systems of distributed generation, the performance in frequency that have presented under some frequency perturbation, as well as the influence that can have on the national and regional electrical system, with different amounts of technologies included in the national system. The recommended settings are evaluated through simulations in PSSE program in the context of the behavior of the frequency in the national electric system [es

  1. Goodness-of-Fit Tests for Generalized Normal Distribution for Use in Hydrological Frequency Analysis

    Science.gov (United States)

    Das, Samiran

    2018-04-01

    The use of three-parameter generalized normal (GNO) as a hydrological frequency distribution is well recognized, but its application is limited due to unavailability of popular goodness-of-fit (GOF) test statistics. This study develops popular empirical distribution function (EDF)-based test statistics to investigate the goodness-of-fit of the GNO distribution. The focus is on the case most relevant to the hydrologist, namely, that in which the parameter values are unidentified and estimated from a sample using the method of L-moments. The widely used EDF tests such as Kolmogorov-Smirnov, Cramer von Mises, and Anderson-Darling (AD) are considered in this study. A modified version of AD, namely, the Modified Anderson-Darling (MAD) test, is also considered and its performance is assessed against other EDF tests using a power study that incorporates six specific Wakeby distributions (WA-1, WA-2, WA-3, WA-4, WA-5, and WA-6) as the alternative distributions. The critical values of the proposed test statistics are approximated using Monte Carlo techniques and are summarized in chart and regression equation form to show the dependence of shape parameter and sample size. The performance results obtained from the power study suggest that the AD and a variant of the MAD (MAD-L) are the most powerful tests. Finally, the study performs case studies involving annual maximum flow data of selected gauged sites from Irish and US catchments to show the application of the derived critical values and recommends further assessments to be carried out on flow data sets of rivers with various hydrological regimes.

  2. Frequency Distribution of Blood Groups ABO, MN and Rh Factor in Philippine Cosmopolitan, Regional and the National Populations

    OpenAIRE

    Ruth Marian S. Guzman; Ricardo Noel R. Gervasio; Ian Kendrich C. Fontanilla; Ernelea P. Cao

    2009-01-01

    Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. Blood groups include the ABO, Rh and the MN red cell antigens. The frequency distribution of these three blood groups were obtained and assessed for differences from three populations: (1) a regional population from the town of Cabagan located in Isabela province; (2) a cosmopolitan population from the University of the Philippines’ r...

  3. Spectral distribution of the efficiency of terahertz difference frequency generation upon collinear propagation of interacting waves in semiconductor crystals

    International Nuclear Information System (INIS)

    Orlov, Sergei N; Polivanov, Yurii N

    2007-01-01

    Dispersion phase matching curves and spectral distributions of the efficiency of difference frequency generation in the terahertz range are calculated for collinear propagation of interacting waves in zinc blende semiconductor crystals (ZnTe, CdTe, GaP, GaAs). The effect of the pump wavelength, the nonlinear crystal length and absorption in the terahertz range on the spectral distribution of the efficiency of difference frequency generation is analysed. (nonlinear optical phenomena)

  4. Histology and Gadolinium Distribution in the Rodent Brain After the Administration of Cumulative High Doses of Linear and Macrocyclic Gadolinium-Based Contrast Agents

    Science.gov (United States)

    Lohrke, Jessica; Frisk, Anna-Lena; Frenzel, Thomas; Schöckel, Laura; Rosenbruch, Martin; Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin A.; Nischwitz, Volker; Küppers, Astrid; Pietsch, Hubertus

    2017-01-01

    Objectives Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution. Materials and Methods Fifty male Wistar-Han rats were randomly allocated into control (saline, n = 10 rats) and 4 GBCA groups (linear GBCAs: gadodiamide and gadopentetate dimeglumine, macrocyclic GBCAs: gadobutrol and gadoteridol; n = 10 rats per group). The animals received 20 daily intravenous injections at a dose of 2.5 mmol Gd/kg body weight. Eight weeks after the last GBCA administration, the animals were killed, and the brain and skin samples were histopathologically assessed (hematoxylin and eosin; cresyl violet [Nissl]) and by immunohistochemistry. The Gd concentration in the skin, bone, brain, and skeletal muscle samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS, n = 4). The spatial Gd distribution in the brain and skin samples was analyzed in cryosections using laser ablation coupled with ICP-MS (LA-ICP-MS, n = 3). For the ultra-high resolution of Gd distribution, brain sections of rats injected with gadodiamide or saline (n = 1) were assessed by scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and transmission electron microscopy, respectively. Results No histological changes were observed in the brain. In contrast, 4 of 10 animals in the gadodiamide group but none of the animals in other groups showed macroscopic and histological

  5. Histology and Gadolinium Distribution in the Rodent Brain After the Administration of Cumulative High Doses of Linear and Macrocyclic Gadolinium-Based Contrast Agents.

    Science.gov (United States)

    Lohrke, Jessica; Frisk, Anna-Lena; Frenzel, Thomas; Schöckel, Laura; Rosenbruch, Martin; Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin A; Nischwitz, Volker; Küppers, Astrid; Pietsch, Hubertus

    2017-06-01

    Retrospective studies in patients with primary brain tumors or other central nervous system pathologies as well as postmortem studies have suggested that gadolinium (Gd) deposition occurs in the dentate nucleus (DN) and globus pallidus (GP) after multiple administrations of primarily linear Gd-based contrast agents (GBCAs). However, this deposition has not been associated with any adverse effects or histopathological alterations. The aim of this preclinical study was to systematically examine differences between linear and macrocyclic GBCAs in their potential to induce changes in brain and skin histology including Gd distribution in high spatial resolution. Fifty male Wistar-Han rats were randomly allocated into control (saline, n = 10 rats) and 4 GBCA groups (linear GBCAs: gadodiamide and gadopentetate dimeglumine, macrocyclic GBCAs: gadobutrol and gadoteridol; n = 10 rats per group). The animals received 20 daily intravenous injections at a dose of 2.5 mmol Gd/kg body weight. Eight weeks after the last GBCA administration, the animals were killed, and the brain and skin samples were histopathologically assessed (hematoxylin and eosin; cresyl violet [Nissl]) and by immunohistochemistry. The Gd concentration in the skin, bone, brain, and skeletal muscle samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS, n = 4). The spatial Gd distribution in the brain and skin samples was analyzed in cryosections using laser ablation coupled with ICP-MS (LA-ICP-MS, n = 3). For the ultra-high resolution of Gd distribution, brain sections of rats injected with gadodiamide or saline (n = 1) were assessed by scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and transmission electron microscopy, respectively. No histological changes were observed in the brain. In contrast, 4 of 10 animals in the gadodiamide group but none of the animals in other groups showed macroscopic and histological nephrogenic systemic fibrosis-like skin

  6. Combined distributed Raman and Bragg fiber temperature sensing using incoherent optical frequency domain reflectometry

    Directory of Open Access Journals (Sweden)

    M. Koeppel

    2018-02-01

    Full Text Available Optical temperature sensors offer unique features which make them indispensable for key industries such as the energy sector. However, commercially available systems are usually designed to perform either distributed or distinct hot spot temperature measurements since they are restricted to one measurement principle. We have combined two concepts, fiber Bragg grating (FBG temperature sensors and Raman-based distributed temperature sensing (DTS, to overcome these limitations. Using a technique called incoherent optical frequency domain reflectometry (IOFDR, it is possible to cascade several FBGs with the same Bragg wavelength in one fiber and simultaneously perform truly distributed Raman temperature measurements. In our lab we have achieved a standard deviation of 2.5 K or better at a spatial resolution in the order of 1 m with the Raman DTS. We have also carried out a field test in a high-voltage environment with strong magnetic fields where we performed simultaneous Raman and FBG temperature measurements using a single sensor fiber only.

  7. AFD: an application for bi-molecular interaction using axial frequency distribution.

    Science.gov (United States)

    Raza, Saad; Azam, Syed Sikander

    2018-03-06

    Conformational flexibility and generalized structural features are responsible for specific phenomena existing in biological pathways. With advancements in computational chemistry, novel approaches and new methods are required to compare the dynamic nature of biomolecules, which are crucial not only to address dynamic functional relationships but also to gain detailed insights into the disturbance and positional fluctuation responsible for functional shifts. Keeping this in mind, axial frequency distribution (AFD) has been developed, designed, and implemented. AFD can profoundly represent distribution and density of ligand atom around a particular atom or set of atoms. It enabled us to obtain an explanation of local movements and rotations, which are not significantly highlighted by any other structural and dynamical parameters. AFD can be implemented on biological models representing ligand and protein interactions. It shows a comprehensive view of the binding pattern of ligand by exploring the distribution of atoms relative to the x-y plane of the system. By taking a relative centroid on protein or ligand, molecular interactions like hydrogen bonds, van der Waals, polar or ionic interaction can be analyzed to cater the ligand movement, stabilization or flexibility with respect to the protein. The AFD graph resulted in the residual depiction of bi-molecular interaction in gradient form which can yield specific information depending upon the system of interest.

  8. Spatially distributed patterns of oscillatory coupling between high-frequency amplitudes and low-frequency phases in human iEEG

    NARCIS (Netherlands)

    Maris, Eric; van Vugt, Marieke; Kahana, Michael

    2011-01-01

    Spatially distributed coherent oscillations provide temporal windows of excitability that allow for interactions between distinct neuronal groups. It has been hypothesized that this mechanism for neuronal communication is realized by bursts of high-frequency oscillations that are phase-coupled to a

  9. EXAFS cumulants of CdSe

    International Nuclear Information System (INIS)

    Diop, D.

    1997-04-01

    EXAFS functions had been extracted from measurements on the K edge of Se at different temperatures between 20 and 300 K. The analysis of the EXAFS of the filtered first two shells has been done in the wavevector range laying between 2 and 15.5 A -1 in terms of the cumulants of the effective distribution of distances. The cumulants C 3 and C 4 obtained from the phase difference and the amplitude ratio methods have shown the anharmonicity in the vibrations of atoms around their equilibrium position. (author). 13 refs, 3 figs

  10. The Effect of Total Cumulative Dose, Number of Treatment Cycles, Interval between Injections, and Length of Treatment on the Frequency of Occurrence of Antibodies to Botulinum Toxin Type A in the Treatment of Muscle Spasticity

    Science.gov (United States)

    Bakheit, Abdel Magid O.; Liptrot, Anthea; Newton, Rachel; Pickett, Andrew M.

    2012-01-01

    A large cumulative dose of botulinum toxin type A (BoNT-A), frequent injections, a short interval between treatment cycles, and a long duration of treatment have all been suggested, but not confirmed, to be associated with a high incidence of neutralizing antibodies to the neurotoxin. The aim of this study was to investigate whether these…

  11. Discrete- and finite-bandwidth-frequency distributions in nonlinear stability applications

    Science.gov (United States)

    Kuehl, Joseph J.

    2017-02-01

    A new "wave packet" formulation of the parabolized stability equations method is presented. This method accounts for the influence of finite-bandwidth-frequency distributions on nonlinear stability calculations. The methodology is motivated by convolution integrals and is found to appropriately represent nonlinear energy transfer between primary modes and harmonics, in particular nonlinear feedback, via a "nonlinear coupling coefficient." It is found that traditional discrete mode formulations overestimate nonlinear feedback by approximately 70%. This results in smaller maximum disturbance amplitudes than those observed experimentally. The new formulation corrects this overestimation, accounts for the generation of side lobes responsible for spectral broadening, and results in disturbance representation more consistent with the experiment than traditional formulations. A Mach 6 flared-cone example is presented.

  12. LARGE SCALE DISTRIBUTED PARAMETER MODEL OF MAIN MAGNET SYSTEM AND FREQUENCY DECOMPOSITION ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    ZHANG,W.; MARNERIS, I.; SANDBERG, J.

    2007-06-25

    Large accelerator main magnet system consists of hundreds, even thousands, of dipole magnets. They are linked together under selected configurations to provide highly uniform dipole fields when powered. Distributed capacitance, insulation resistance, coil resistance, magnet inductance, and coupling inductance of upper and lower pancakes make each magnet a complex network. When all dipole magnets are chained together in a circle, they become a coupled pair of very high order complex ladder networks. In this study, a network of more than thousand inductive, capacitive or resistive elements are used to model an actual system. The circuit is a large-scale network. Its equivalent polynomial form has several hundred degrees. Analysis of this high order circuit and simulation of the response of any or all components is often computationally infeasible. We present methods to use frequency decomposition approach to effectively simulate and analyze magnet configuration and power supply topologies.

  13. Distributed Model Predictive Load Frequency Control of Multi-area Power System with DFIGs

    Institute of Scientific and Technical Information of China (English)

    Yi Zhang; Xiangjie Liu; Bin Qu

    2017-01-01

    Reliable load frequency control(LFC) is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-area interconnected power system with wind turbines, this paper presents a distributed model predictive control(DMPC) based on coordination scheme.The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The generation rate constraints(GRCs), load disturbance changes, and the wind speed constraints are considered. Furthermore, the DMPC algorithm may reduce the impact of the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and without the participation of the wind turbines is carried out. Analysis and simulation results show possible improvements on closed–loop performance, and computational burden with the physical constraints.

  14. Crater size-frequency distributions and a revised Martian relative chronology

    International Nuclear Information System (INIS)

    Barlow, N.G.

    1988-01-01

    A relative plotting technique is applied to Viking 1:2M photomosaics of 25,826 Martian craters of diameter greater than 8 km and age younger than that of the Martian surface. The size-frequency distribution curves are calculated and analyzed in detail, and the results are presented in extensive tables and maps. It is found that about 60 percent of the crater-containing lithologic units, including many small volcanoes and the ridged planes, were formed during the heavy-bombardment period (HBP), while 40 percent arose after the HBP. Wide region-to-region variation in the crater density is noted, and localized age estimates are provided. 42 references

  15. Cumulative environmental effects. Summary

    International Nuclear Information System (INIS)

    2012-01-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  16. Cumulative environmental effects. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  17. pH and its frequency distribution patterns of Acid Precipitation in Japan

    International Nuclear Information System (INIS)

    Kitamura, Moritsugu; Katou, Takunori; Sekiguchi, Kyoichi

    1991-01-01

    The pH data was collected at the 29 stations in Phase-I study of Acid Precipitation Survey over Japan by Japan Environment Agency in terms of frequency distribution patterns. This study was undertaken from April 1984 to March 1988, which was the first survey of acid precipitation over Japan with identical sampling procedures and subsequent chemical analyses. While the annual mean pH at each station ranged from 4.4 to 5.5, the monthly mean varied more widely, from 4.0 to 7.1. Its frequency distribution pattern was obtained for each station, and further grouped into four classes: class I; a mode at the rank of pH 4.5∼4.9, class II; bimodes above and below this pH region, class III; a mode at a higher pH region, class IV; a mode at a lower pH region. The bimodal pattern was suggestive of precipitation with and without incorporation of significant amounts of basic aerosol of anthropogenic origin during descent of rain droplet. The patterns of the stations were also classified on a basis of summer-winter difference into another four classes. Winter pH values were appreciably lower than summer pHs in western parts of Japan and on Japan Sea coast, we attribute the winter pH to probable contribution of acidic pollutants transported by strong winter monsoon from Eurasian Continent. At most stations in northern and eastern Japan, the pH was higher in winter months reflecting more incorporation of basic materials, e.g., NH 4 + and Ca 2+ . (author)

  18. Frequency and distribution of leakages in steam generators of gas-cooled reactors

    International Nuclear Information System (INIS)

    Bongratz, R.; Breitbach, G.; Wolters, J.

    1988-01-01

    In gas cooled reactors with graphitic primary circuit structures - such as HTR, AGR or Magnox - the water ingress is an event of great safety concern. Water or steam entering the primary circuit react with the hot graphite and carbon-oxide and hydrogen are produced. As the most important initiating event a leak in a steam generator must be taken into account. From the safety point of view as well as for availability reasons it is necessary to construct reliable boilers. Thus the occurrence of a boiler leak should be a rare event. In the context of a probabilistic safety study for an HTR-Project much effort was invested to get information about the frequency and the size distribution of tube failures in steam generators of gas cooled reactors. The main data base was the boiler tube failure statistics of United Kingdom gas cooled reactors. The data were selected and applied to a modern HTR steam generator design. A review of the data showed that the failure frequency is not connected with the load level (pressures, temperatures) or with the geometric size of the heating surface of the boiler. Design, construction, fabrication, examination and operation conditions have the greatest influence an the failure frequency but they are practically not to be quantified. The typical leak develops from smallest size. By erosion effects of the entering water or steam it is enlarged to perhaps some mm 2 , then usually it is detected by moisture monitors. Sudden tube breaks were not reported in the investigated period. As a rule boiler leaks in gas cooled reactors are much more, rare then leaks in steam generators of light water reactors and fossil fired boilers. (author)

  19. How old are lunar lobate scarps? 1. Seismic resetting of crater size-frequency distributions

    Science.gov (United States)

    van der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

    2018-05-01

    Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

  20. Analysis and applications of a frequency selective surface via a random distribution method

    International Nuclear Information System (INIS)

    Xie Shao-Yi; Huang Jing-Jian; Yuan Nai-Chang; Liu Li-Guo

    2014-01-01

    A novel frequency selective surface (FSS) for reducing radar cross section (RCS) is proposed in this paper. This FSS is based on the random distribution method, so it can be called random surface. In this paper, the stacked patches serving as periodic elements are employed for RCS reduction. Previous work has demonstrated the efficiency by utilizing the microstrip patches, especially for the reflectarray. First, the relevant theory of the method is described. Then a sample of a three-layer variable-sized stacked patch random surface with a dimension of 260 mm×260 mm is simulated, fabricated, and measured in order to demonstrate the validity of the proposed design. For the normal incidence, the 8-dB RCS reduction can be achieved both by the simulation and the measurement in 8 GHz–13 GHz. The oblique incidence of 30° is also investigated, in which the 7-dB RCS reduction can be obtained in a frequency range of 8 GHz–14 GHz. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  1. How Old are Lunar Lobate Scarps? 1. Seismic Resetting of Crater Size-Frequency Distributions

    Science.gov (United States)

    Van Der Bogert, Carolyn H.; Clark, Jaclyn D.; Hiesinger, Harald; Banks, Maria E.; Watters, Thomas R.; Robinson, Mark S.

    2018-01-01

    Previous studies have estimated the ages of lunar lobate scarps, some of the youngest tectonic landforms on the Moon, based on the estimated life-times of their fresh morphologies and associated small graben, using crater degradation ages, or via buffered and traditional crater size-frequency distribution (CSFD) measurements. Here, we reexamine five scarps previously dated by Binder and Gunga (1985) with crater degradation ages to benchmark the evaluation of both the buffered and traditional CSFD approaches for determination of absolute model ages (AMAs) at scarps. Both CSFD methods yield similar ages for each individual scarp, indicating that fault activity not only can be measured on the scarp itself, but also in the surrounding terrain - an indication that tectonic activity causes surface renewal both adjacent to and even kilometers distant from scarps. Size-frequency variations in the regions surrounding the scarps are thus useful for studying the extent and severity of the ground motion caused by coseismic slip events during scarp formation. All age determination approaches continue to indicate that lunar lobate scarps were active in the late Copernican, with some scarps possibly experiencing activity within the last 100 Ma.

  2. Spectral line shapes in linear absorption and two-dimensional spectroscopy with skewed frequency distributions

    NARCIS (Netherlands)

    Farag, Marwa H.; Hoenders, Bernhard J.; Knoester, Jasper; Jansen, Thomas L. C.

    2017-01-01

    The effect of Gaussian dynamics on the line shapes in linear absorption and two-dimensional correlation spectroscopy is well understood as the second-order cumulant expansion provides exact spectra. Gaussian solvent dynamics can be well analyzed using slope line analysis of two-dimensional

  3. Analysis of a hundred-years series of magnetic activity indices. III. Is the frequency distribution logarithmo-normal

    International Nuclear Information System (INIS)

    Mayaud, P.N.

    1976-01-01

    Because of the various components of positive conservation existing in the series of aa indices, their frequency distribution is necessarily distorted with respect to any random distribution. However when one takes these various components into account, the observed distribution can be considered as being a logarithmo-normal distribution. This implies that the geomagnetic activity satisfies the conditions of the central limit theorem, according to which a phenomenon which presents such a distribution is due to independent causes whose effects are multiplicative. Furthermore, the distorsion of the frequency distribution caused by the 11-year and 90-year cycles corresponds to a pure attenuation effect; an interpretation by the solar 'coronal holes' is proposed [fr

  4. Cumulative stress and autonomic dysregulation in a community sample.

    Science.gov (United States)

    Lampert, Rachel; Tuit, Keri; Hong, Kwang-Ik; Donovan, Theresa; Lee, Forrester; Sinha, Rajita

    2016-05-01

    Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.

  5. Tuning and optimization of the field distribution for 4-rod Radio Frequency Quadrupole linacs

    International Nuclear Information System (INIS)

    Schmidt, Janet Susan

    2014-01-01

    In this thesis, the tuning process of the 4-rod Radio Frequency Quadrupole has been analyzed and a theory for the prediction of the tuning plate's influence on the longitudinal voltage distribution was developed together with RF design options for the optimization of the fringe fields. The basic principles of the RFQ's particle dynamics and resonant behavior are introduced in the theory part of this thesis. All studies that are presented are based on the work on four RFQs of recent linac projects. These RFQs are described in one chapter. Here, the projects are introduced together with details about the RFQ parameters and performance. In the meantime two of these RFQs are in full operation at NSCL at MSU and FNAL. One is operating in the test phase of the MedAustron Cancer Therapy Center and the fourth one for LANL is about to be built. The longitudinal voltage distribution has been studied in detail with a focus on the influence of the RF design with tuning elements and parameters like the electrodes overlap or the distance between stems. The theory for simulation methods for the field flatness that were developed as part of this thesis, as well as its simulation with CST MWS have been analyzed and compared to measurements. The lumped circuit model has proven to predict results with an accuracy that can be used in the tuning process of 4-rod RFQs. Together with results from the tuning studies, the studies on the fringe fields of the 4-rod structure lead to a proposal for a 4-rod RFQ model with an improved field distribution in the transverse and longitudinal electric field.

  6. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Gray, W.M.; Watson, E.R.

    1977-01-01

    In five previous papers, the concept of Cumulative Radiation Effect (CRE) has been presented as a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Simple nomographic and tabular methods for the solution of practical problems in radiotherapy are now described. An essential feature of solving a CRE problem is firstly to present it in a concise and readily appreciated form, and, to do this, nomenclature has been introduced to describe schedules and regimes as compactly as possible. Simple algebraic equations have been derived to describe the CRE achieved by multi-schedule regimes. In these equations, the equivalence conditions existing at the junctions between schedules are not explicit and the equations are based on the CREs of the constituent schedules assessed individually without reference to their context in the regime as a whole. This independent evaluation of CREs for each schedule has resulted in a considerable simplification in the calculation of complex problems. The calculations are further simplified by the use of suitable tables and nomograms, so that the mathematics involved is reduced to simple arithmetical operations which require at the most the use of a slide rule but can be done by hand. The order of procedure in the presentation and calculation of CRE problems can be summarised in an evaluation procedure sheet. The resulting simple methods for solving practical problems of any complexity on the CRE-system are demonstrated by a number of examples. (author)

  7. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation.

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  8. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  9. [Frequency, nature and distribution of school sport injuries at different types of schools].

    Science.gov (United States)

    Greier, K; Riechelmann, H

    2012-12-01

    A high percentage of all sports injuries occur during school sports. It was analysed whether there are differences in frequency, nature and distribution of school sport injuries at two different types of schools. School sport injuries of all secondary modern schools (n = 106) and in lower classes of grammar Schools (n = 17) in the federal state of Tyrol, Austria, from the ten school years 2001/02 to 2010/11 were analysed. All physical injuries occurring during school sports and resulting in the consultation of a medical doctor and therefore being reported to the general accident department (Allgemeine Unfallversicherungsanstalt [AUVA]) were assessed. During the evaluation period an average number of 32,935 (±1584) school children attended the two types of schools in Tyrol per year. The average incidence of school sports injuries in this ten-year period in both types of schools was 36.4/1,000 (mean) with a standard deviation of 4.4/1,000 per school child per year. The incidence increased from 30.3 in the school year 2001/02 to 40.4 in the school year 2010/11 (r = 0.91; b = 1.34; p school sport injuries at secondary modern schools (37.4 ± 4.9 per 1,000 school children per year) was higher than at the lower classes of grammar schools (32.9 ± 4.0 per 1,000 school children per year; relative risk 1.138; 95% CI = 1.09-1.19; p = 1.8 × 10-8). In addition, the sports injuries of the school year 2010/11 were analysed in detail and a comparison was made between the two types of schools. The distribution pattern of school sports injuries did not show any significant differences between both school types. At the secondary modern schools, as well as in the lower classes of grammar schools, injuries to the upper extremities prevailed (>50%). Ball sports were responsible for every second injury. Secondary modern school pupils had a significantly higher risk of suffering a school sports injury than pupils in the lower classes of grammar schools. The injury pattern did not show

  10. Use of population exposure frequency distributions to simulate effects of policy interventions on NO2 exposure

    Science.gov (United States)

    Dimitroulopoulou, C.; Ashmore, M. R.; Terry, A. C.

    2017-02-01

    Health effects of air pollution on individuals depend on their personal exposure, but few modelling tools are available which can predict how the distribution of personal exposures within a city will change in response to policies to reduce emissions both indoors and outdoors. We describe a new probabilistic modelling framework (INDAIR-2/EXPAIR), which provides predictions of the personal exposure frequency distribution (PEFD) across a city to assess the effects of both reduced emissions from home sources and reduced roadside concentrations on population exposure. The model uses a national time activity database, which gives the percentage of each population group in different residential and non-residential micro-environments, and links this, for the home, to predictions of concentrations from a three-compartment model, and for non-residential microenvironments to empirical indoor/outdoor ratios. This paper presents modelled PEFDs for NO2 in the city of Leicester, for children, the elderly, and office workers, comparing results in different seasons and on different days of the week. While the mean NO2 population exposure was close to, or below the urban background concentration, the 95%ile of the PEFD was well above the urban background concentration. The relationship between both mean and 95%ile PEFD and urban background concentrations was strongly influenced by air exchange rate. The 24 h mean PEFD showed relative small differences between the population groups, with both removal of home sources and reductions of roadside concentrations on roads with a high traffic density having similar effects in reducing mean exposure. In contrast, the 1 h maximum of the PEFD was significantly higher for children and the elderly than for office workers, and showed a much greater response to reduced home emissions in these groups. The results demonstrate the importance of understanding the dynamics of NO2 exposure at a population level within different groups, if the benefits

  11. Diversification Rates and the Evolution of Species Range Size Frequency Distribution

    Directory of Open Access Journals (Sweden)

    Silvia Castiglione

    2017-11-01

    Full Text Available The geographic range sizes frequency distribution (RFD within clades is typically right-skewed with untransformed data, and bell-shaped or slightly left-skewed under the log-transformation. This means that most species within clades occupy diminutive ranges, whereas just a few species are truly widespread. A number of ecological and evolutionary explanations have been proposed to account for this pattern. Among the latter, much attention has been given to the issue of how extinction and speciation probabilities influence RFD. Numerous accounts now convincingly demonstrate that extinction rate decreases with range size, both in living and extinct taxa. The relationship between range size and speciation rate, though, is much less obvious, with either small or large ranged species being proposed to originate more daughter taxa. Herein, we used a large fossil database including 21 animal clades and more than 80,000 fossil occurrences distributed over more than 400 million years of marine metazoans (exclusive of vertebrates evolution, to test the relationship between extinction rate, speciation rate, and range size. As expected, we found that extinction rate almost linearly decreases with range size. In contrast, speciation rate peaks at the large (but not the largest end of the range size spectrum. This is consistent with the peripheral isolation mode of allopatric speciation being the main mechanism of species origination. The huge variation in phylogeny, fossilization potential, time of fossilization, and the overarching effect of mass extinctions suggest caution must be posed at generalizing our results, as individual clades may deviate significantly from the general pattern.

  12. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 2: Crater Size-frequency Distribution Curves and Geomorphic Unit Ages

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    In assessing the relative ages of the geomorphic/geologic units, crater counts of the entire unit or nearly the entire unit were made and summed in order to get a more accurate value than obtainable by counts of isolated sections of each unit. Cumulative size-frequency counts show some interesting relationships. Most of the units show two distinct crater populations with a flattening out of the distribution curve at and below 10 km diameter craters. Above this crater size the curves for the different units diverge most notably. In general, the variance may reflect the relative ages of these units. At times, however, in the larger crater size range, these curves can overlap and cross on another. Also the error bars at these larger sizes are broader (and thus more suspect), since counts of larger craters show more scatter, whereas the unit areas remain constant. Occasional clusters of relatively large craters within a given unit, particularly one of limited areal extent, can affect the curve so that the unit might seem to be older than units which it overlies or cuts.

  13. Size-Frequency Distributions of Rocks on Mars and Earth Analog Sites: Implications for Future Landed Missions

    Science.gov (United States)

    Golombeck, M.; Rapp, D.

    1996-01-01

    The size-frequency distribution of rocks and the Vicking landing sites and a variety of rocky locations on the Earth that formed from a number of geologic processes all have the general shape of simple exponential curves, which have been combined with remote sensing data and models on rock abundance to predict the frequency of boulders potentially hazardous to future Mars landers and rovers.

  14. High-frequency oscillations in distributed neural networks reveal the dynamics of human decision making

    Directory of Open Access Journals (Sweden)

    Adrian G Guggisberg

    2008-03-01

    Full Text Available We examine the relative timing of numerous brain regions involved in human decisions that are based on external criteria, learned information, personal preferences, or unconstrained internal considerations. Using magnetoencephalography (MEG and advanced signal analysis techniques, we were able to non-invasively reconstruct oscillations of distributed neural networks in the high-gamma frequency band (60–150 Hz. The time course of the observed neural activity suggested that two-alternative forced choice tasks are processed in four overlapping stages: processing of sensory input, option evaluation, intention formation, and action execution. Visual areas are activated fi rst, and show recurring activations throughout the entire decision process. The temporo-occipital junction and the intraparietal sulcus are active during evaluation of external values of the options, 250–500 ms after stimulus presentation. Simultaneously, personal preference is mediated by cortical midline structures. Subsequently, the posterior parietal and superior occipital cortices appear to encode intention, with different subregions being responsible for different types of choice. The cerebellum and inferior parietal cortex are recruited for internal generation of decisions and actions, when all options have the same value. Action execution was accompanied by activation peaks in the contralateral motor cortex. These results suggest that high-gamma oscillations as recorded by MEG allow a reliable reconstruction of decision processes with excellent spatiotemporal resolution.

  15. Frequency Distribution of Hearing Disorders Among the Student of Public Elementary School in Neishaboor

    Directory of Open Access Journals (Sweden)

    Dr. Mohammad Kamali

    2000-05-01

    Full Text Available Objectives: determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, Impedance Audiometiy and questionnaires. Methods and Materials: This study was carried out in a cross - sectional descriptive survey - on 1200 students (600 girls and 600 boys among the student of primary school of Neishabbor, academic year 1376-77 Results: 1- Otoscopy examination; abnormal conditions of external ear canal was found in 14.1% of cases; mostly impacted ceruman (13.6%; Abnormal conditions of tympanic membrane (0.4% and foreign body 0.16%. Abnormal conditions of external ear canal was statistically unmeaningful. (P V=0 .8 2- Impedance Audiometiy: 5. 75% Abnormal tympanograms were observed, mostly type C (3.15% 3- Pure Tone Audiometry: An overall 5.5% hearing loss was found in this population including 3% bilateral and 1.25% unilateral hearing loss. Only conductive hearing loss was found in this population (2.7% in right ear and 3.5% in left ear, PV=0.9. Hearing loss observed mostly in girls but the difference was slight. Family background showed no effects on the hearing disorders.9.8% of cases were in need of medical care and 0.3% were in need of rehabilitation services. Only 28.8% of parents, 36.3% of teachers and 40.9% of afflicted students were aware of the problem.

  16. 18F-PET imaging: frequency, distribution and appearance of benign lesions

    International Nuclear Information System (INIS)

    Schirrmeister, H.; Kotzerke, J.; Rentschler, M.; Traeger, H.; Fenchel, S.; Diederichs, C.G.; Reske, S.N.; Nuessle, K.

    1998-01-01

    Purpose: We evaluated the frequency, distribution and appearance of benign lesions in 18 F-PET scans. Methods: Between March 1996 and May 1997, 18 F-PET scans were performed in 59 patients in addition to conventional planar bone scintigraphy. Eleven patients were subjected to additional SPECT imaging. The main indication was searching for bone metastases (58 pat.). The diagnosis was confirmed radiologically. Results: With 18 F-PET in 39 patients (66,1%) 152 benign lesions, mostly located in the spine were detected. 99m Tc bone scans revealed 45 lesions in 10 patients. Osteoarthritis of the intervertebral articulations (69%) or of the acromioclavicular joint (15%) were the most common reasons for degenerative lesions detected with 18 F-PET. Osteophytes appeared as hot lesions located at two adjacent vertebral endplates. Osteoarthritis of the intervertebral articulations showed an enhanced tracer uptake at these localizations, whereas endplate fractures of the vertebral bodies appeared very typically; solitary fractures of the ribs could not be differentiated from metastases. Rare benign lesions were not studied. Conclusion: Most of the degenerative lesions (84%) detected with 18 F-PET had a very typical appearance and could be detected with the improved spatial resolution and advantages of a tomographic technique. 18 F-PET had an increased accuracy in detecting degenerative bone lesions. (orig.) [de

  17. Seasonal Variation and Frequency Distribution of Ectoparasites in Crossbreed Cattle in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Ferraz da Costa

    2014-01-01

    Full Text Available The aims of this study were to evaluate the seasonal variation and frequency distribution of Rhipicephalus (Boophilus microplus, Haematobia irritans, and Dermatobia hominis on crossbred heifers under field conditions in the northeast of Minas Gerais state, southeastern Brazil. From November 2007 to September 2009 (23 months, 40 heifers aged 16.6±2.4 months were divided into groups A (1/4 Holstein × 3/4 Gir and B (1/2 Holstein × 1/2 Gir and had the monthly infestation estimated along with the climatic conditions. The mean maximum and minimum temperatures were 28.5 and 19°C, respectively. The ectoparasites were present on animals in all months of the year. The levels of ticks on the animals were low (3.0±0.2 ticks/animal, with the highest density in midwinter. The temperature was the climatic factor that most influenced the tick levels. The population of H. irritans (13.9±0.3 flies/animal and D. hominis (1.5±0.2 larvae/animal on heifers was more influenced by rainfall and exhibited two population peaks during the year. 1/2 Holstein heifers harbored significantly more H. irritans and D. hominis than 1/4 Holstein heifers. The results are discussed considering the most appropriate periods to apply ectoparasiticides and the genetic make-up of the animals.

  18. Seasonal Variation and Frequency Distribution of Ectoparasites in Crossbreed Cattle in Southeastern Brazil

    Science.gov (United States)

    Ferraz da Costa, Maria do Socorro; Guimarães, Marcos Pezzi; Lima, Walter dos Santos; Ferraz da Costa, Ana Julia; Facury Filho, Elias Jorge; Araujo, Ricardo Nascimento

    2014-01-01

    The aims of this study were to evaluate the seasonal variation and frequency distribution of Rhipicephalus (Boophilus) microplus, Haematobia irritans, and Dermatobia hominis on crossbred heifers under field conditions in the northeast of Minas Gerais state, southeastern Brazil. From November 2007 to September 2009 (23 months), 40 heifers aged 16.6 ± 2.4 months were divided into groups A (1/4 Holstein × 3/4 Gir) and B (1/2 Holstein × 1/2 Gir) and had the monthly infestation estimated along with the climatic conditions. The mean maximum and minimum temperatures were 28.5 and 19°C, respectively. The ectoparasites were present on animals in all months of the year. The levels of ticks on the animals were low (3.0 ± 0.2 ticks/animal), with the highest density in midwinter. The temperature was the climatic factor that most influenced the tick levels. The population of H. irritans (13.9 ± 0.3 flies/animal) and D. hominis (1.5 ± 0.2 larvae/animal) on heifers was more influenced by rainfall and exhibited two population peaks during the year. 1/2 Holstein heifers harbored significantly more H. irritans and D. hominis than 1/4 Holstein heifers. The results are discussed considering the most appropriate periods to apply ectoparasiticides and the genetic make-up of the animals. PMID:26464941

  19. A High Performance Frequency Standard and Distribution System for Cassini Ka-Band Experiment

    National Research Council Canada - National Science Library

    Wang, R. T; Calhoun, M. D; Kirk, A; Diener, W. A; Dick, G. J; Tjoelker, R. L

    2005-01-01

    ...), and 10 Kelvin Cryocooled Sapphire Oscillator (10K CSO) and frequency-lock-loop, are integrated to achieve the very high performance, ground based frequency reference at a remote antenna site located 16 km from the hydrogen maser...

  20. Secant cumulants and toric geometry

    NARCIS (Netherlands)

    Michalek, M.; Oeding, L.; Zwiernik, P.W.

    2012-01-01

    We study the secant line variety of the Segre product of projective spaces using special cumulant coordinates adapted for secant varieties. We show that the secant variety is covered by open normal toric varieties. We prove that in cumulant coordinates its ideal is generated by binomial quadrics. We

  1. Sharing a quota on cumulative carbon emissions

    International Nuclear Information System (INIS)

    Raupach, Michael R.; Davis, Steven J.; Peters, Glen P.; Andrew, Robbie M.; Canadell, Josep G.; Ciais, Philippe

    2014-01-01

    Any limit on future global warming is associated with a quota on cumulative global CO 2 emissions. We translate this global carbon quota to regional and national scales, on a spectrum of sharing principles that extends from continuation of the present distribution of emissions to an equal per-capita distribution of cumulative emissions. A blend of these endpoints emerges as the most viable option. For a carbon quota consistent with a 2 C warming limit (relative to pre-industrial levels), the necessary long-term mitigation rates are very challenging (typically over 5% per year), both because of strong limits on future emissions from the global carbon quota and also the likely short-term persistence in emissions growth in many regions. (authors)

  2. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea.

    Science.gov (United States)

    Lozano-Cortés, Diego F; Berumen, Michael L

    2016-04-30

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north-south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Comptonization of low-frequency radiation in accretion disks Angular distribution and polarization of hard X-ray radiation

    International Nuclear Information System (INIS)

    Suniaev, R.A.; Titarchuk, L.G.

    1984-01-01

    Analytical consideration is given to the comptonization of photons and its effects on the radiation emitted from accretion disks of compact X-ray sources, such as black holes and neutron stars. Attention is given to the photon distribution during escape from the disk, the angular distribution of hard radiation from the disk, the polarization of hard radiation and the electron temperature distribution over the optical depth. It is shown that the hard radiation spectrum is independent of the low-frequency photon source distribution. The angular distribution and polarization of the outgoing X-rays are a function of the optical depth. A Thomson approximation is used to estimate the angular distribution of the hard radiation and the polarization over the disk. The polarization results are compared with OSO-8 satellite data for Cyg X-1 and show good agreement at several energy levels. 17 references

  4. Frequency of distribution of leptin receptor gene polymorphism in obstructive sleep apnea patients.

    Science.gov (United States)

    Popko, K; Gorska, E; Wasik, M; Stoklosa, A; Pływaczewski, R; Winiarska, M; Gorecka, D; Sliwinski, P; Demkow, U

    2007-11-01

    Leptin is an adipocyte-derived hormone regulating energy homeostasis and body weight. Leptin concentration is increased in patients with the obstructive sleep apnea syndrome (OSAS). Leptin receptor (LEPR) is a single transmembrane protein belonging to the superfamily of cytokine receptors related by a structure to the hemopoietin receptor family. The aim of the present study was to evaluate the frequency of distribution of leptin receptor gene polymorphism GLN223ARG in OSAS patients compared with healthy controls. The examined group included 179 subjects: 102 OSAS patients (74 men and 28 women) and 77 non-apneic controls (39 men and 38 women). Genomic DNA was isolated with the use of a column method and genotyping of DNA sequence variation was carried out by restriction enzyme analysis of PCR-amplified DNA. The results revealed a significant correlation between the polymorphism of LEPR and OSAS. Carriers of Arg allele in homozygotic genotype Arg/Arg and heterozygotic genotype Gln/Arg were more often obese and developed OSAS than the group of carriers of homozygotic Gln/Gln genotype. This tendency was observed in the whole examined population and in the group of obese women. We also found the highest levels of total cholesterol, LDL, HDL, and triglycerides in the group of homozygotic Arg/Arg genotype carriers, lower in heterozygotic Gln/Arg genotype carriers, and the lowest in the group of persons carring homozygotic Gln/Gln genotype. The presence of Arg allel seems linked to a higher risk of obesity and higher lipid levels in OSAS patients. OSAS may have a strong genetic basis due to the effects from a variety of genes including those for leptin receptor.

  5. A statistical approach to quantification of genetically modified organisms (GMO) using frequency distributions.

    Science.gov (United States)

    Gerdes, Lars; Busch, Ulrich; Pecoraro, Sven

    2014-12-14

    According to Regulation (EU) No 619/2011, trace amounts of non-authorised genetically modified organisms (GMO) in feed are tolerated within the EU if certain prerequisites are met. Tolerable traces must not exceed the so-called 'minimum required performance limit' (MRPL), which was defined according to the mentioned regulation to correspond to 0.1% mass fraction per ingredient. Therefore, not yet authorised GMO (and some GMO whose approvals have expired) have to be quantified at very low level following the qualitative detection in genomic DNA extracted from feed samples. As the results of quantitative analysis can imply severe legal and financial consequences for producers or distributors of feed, the quantification results need to be utterly reliable. We developed a statistical approach to investigate the experimental measurement variability within one 96-well PCR plate. This approach visualises the frequency distribution as zygosity-corrected relative content of genetically modified material resulting from different combinations of transgene and reference gene Cq values. One application of it is the simulation of the consequences of varying parameters on measurement results. Parameters could be for example replicate numbers or baseline and threshold settings, measurement results could be for example median (class) and relative standard deviation (RSD). All calculations can be done using the built-in functions of Excel without any need for programming. The developed Excel spreadsheets are available (see section 'Availability of supporting data' for details). In most cases, the combination of four PCR replicates for each of the two DNA isolations already resulted in a relative standard deviation of 15% or less. The aims of the study are scientifically based suggestions for minimisation of uncertainty of measurement especially in -but not limited to- the field of GMO quantification at low concentration levels. Four PCR replicates for each of the two DNA isolations

  6. Frequency distributions of Escherichia coli in the confectionery products offered in retail market in Isfahan

    Directory of Open Access Journals (Sweden)

    Rasoul Rezaei

    2016-06-01

    Full Text Available Introduction: Raw ingredients used in confectionary carry high risk of infection with Escherichia coli. Since confectionaries are offered in the market in quite varied forms and types and there is a great difference in the sanitary status of the confectionaries, this study aimed at evaluation of E.coli   frequency distribution in different types of confectionery products in Isfahan market. In addition, the effect of moisture content, products category and the sanitary level of the confectionaries as well as product types (Industrially or traditionally produced on the contamination level were studied. Materials and methods: A total of 200 samples were randomly collected from confectioneries in Isfahan city through simple random sampling method. Preparation and dilution procedures were conducted under sterile conditions. Samples were cultured on EMB agar medium. Later, some of the positive isolates were randomly selected and confirmed by TSI and IMVIC test. Data analysis was performed using descriptive indices. Also, one way ANOVA and LSD test or independent t test were applied to determine the statistically significant difference between the mean E.coli cell numbers in the categorized groups of sweets. Results: It was found that 19% of the total tested samples were contaminated with E.coli strains. The mean, median and maximum of contamination were (35±.5, (0 and (3.4 CFU/gr, respectively. Moisture content, products category and being traditionally or industrially produced have significant effects on the level of contamination; while, the sanitary status of the traditional confectionaries as graded in this study has no impact on the average E.coli cell count. Discussion and conclusion: Regarding the microbial quality, at least about 25% of the sweets in the market do not meet the national standards of confectionary products. Implementation of strict hygiene regulation in the traditional confectionaries is in need to provide the public with

  7. Meal Frequency and Nutrient Distribution: What is Ideal for Body Composition?

    OpenAIRE

    Ryan P Lowery

    2014-01-01

    This article explores the effects of meal frequency on protein synthesis, muscle mass and fat mass. Current research appears to indicate that manipulating meal frequency increases net protein balance and body composition when each meal provides an adequate supply of the amino acid leucine to optimize skeletal muscle anabolism. In contrast, research demonstrating no benefits to increased meal frequency generally employed small, inadequate boluses of protein per meal. The purpose of this paper ...

  8. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  9. A Frequency-List of Sentence Structures: Distribution of Kernel Sentences

    Science.gov (United States)

    Geens, Dirk

    1974-01-01

    A corpus of 10,000 sentences extracted from British theatrical texts was used to construct a frequency list of kernel sentence structures. Thirty-one charts illustrate the analyzed results. The procedures used and an interpretation of the frequencies are given. Such lists might aid foreign language teachers in course organization. Available from…

  10. High cumulants of conserved charges and their statistical uncertainties

    Science.gov (United States)

    Li-Zhu, Chen; Ye-Yin, Zhao; Xue, Pan; Zhi-Ming, Li; Yuan-Fang, Wu

    2017-10-01

    We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million. Supported by NSFC (11405088, 11521064, 11647093), Major State Basic Research Development Program of China (2014CB845402) and Ministry of Science and Technology (MoST) (2016YFE0104800)

  11. The challenge of cumulative impacts

    Energy Technology Data Exchange (ETDEWEB)

    Masden, Elisabeth

    2011-07-01

    Full text: As governments pledge to combat climate change, wind turbines are becoming a common feature of terrestrial and marine environments. Although wind power is a renewable energy source and a means of reducing carbon emissions, there is a need to ensure that the wind farms themselves do not damage the environment. There is particular concern over the impacts of wind farms on bird populations, and with increasing numbers of wind farm proposals, the concern focuses on cumulative impacts. Individually, a wind farm, or indeed any activity/action, may have minor effects on the environment, but collectively these may be significant, potentially greater than the sum of the individual parts acting alone. Cumulative impact assessment is a legislative requirement of environmental impact assessment but such assessments are rarely adequate restricting the acquisition of basic knowledge about the cumulative impacts of wind farms on bird populations. Reasons for this are numerous but a recurring theme is the lack of clear definitions and guidance on how to perform cumulative assessments. Here we present a conceptual framework and include illustrative examples to demonstrate how the framework can be used to improve the planning and execution of cumulative impact assessments. The core concept is that explicit definitions of impacts, actions and scales of assessment are required to reduce uncertainty in the process of assessment and improve communication between stake holders. Only when it is clear what has been included within a cumulative assessment, is it possible to make comparisons between developments. Our framework requires improved legislative guidance on the actions to include in assessments, and advice on the appropriate baselines against which to assess impacts. Cumulative impacts are currently considered on restricted scales (spatial and temporal) relating to individual development assessments. We propose that benefits would be gained from elevating cumulative

  12. Distributed Generation Integration in the Electric Grid: Energy Storage System for Frequency Control

    Directory of Open Access Journals (Sweden)

    Maurizio Delfanti

    2014-01-01

    Full Text Available During the last few years generation from renewable energy sources (RESs has grown considerably in European electrical networks. Transmission system operators are greatly concerned about the impact of RESs on the operational security and efficiency of their networks and more in general of the ENTSO-E interconnected system. Grid codes are to be revised in order to harmonise the rules regarding the connection of RES power plants. A main issue concerns frequency control: frequency is greatly affected by RESs intermittency and its deviations must be limited as much as possible in order to guarantee a suitable level of power quality. To improve frequency stability, in the future, Grid codes could extend frequency control requirements also to RES units, whereas today they are applied only to conventional power plants. Energy storage systems can be a possible solution to increase the flexibility and performance of RES power plants: they allow generators to modulate their power injections without wasting renewable energy. In this paper, the authors studied the suitability of extending frequency control to RES units integrating them with energy storage systems. In particular, the paper focuses on the impact of frequency control on the storage lifetime by analysing the power charge/discharge in response to real frequency oscillations.

  13. Fully-distributed Load Frequency Control Strategy in an Islanded Microgrid Considering Plug-In Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiao Qi

    2018-06-01

    Full Text Available With large-scale integration of electric vehicles, this paper investigates the load frequency control problem in an islanded microgrid with plug-in electric vehicles (PEVs, which can be regarded as mobile battery energy storages to provide a valuable contribution to frequency regulation. A novel fully-distributed control strategy is proposed to achieve fast frequency regulation of islanded microgrids and effective coordination control of distributed energy sources. Firstly, distributed control based on an improved linear active disturbance rejection algorithm is realized through a multi-agent system, and it greatly enhances the anti-disturbance capability of the microgrid. Then, in order to guarantee the effectiveness of PEVs in frequency regulation, PEVs are controlled following the controllable power rate (CPR calculated from the consensus-based multi-agent system. Furthermore, the system control construction in this paper is well designed to avoid the negative effects caused by system communication time delay. Finally, numerical simulations under different disturbances are carried out to demonstrate the effectiveness of the proposed control strategy in comparison with other previous control strategies.

  14. Spatial distribution of cold-season lightning frequency in the coastal areas of the Sea of Japan

    Science.gov (United States)

    Tsurushima, Daiki; Sakaida, Kiyotaka; Honma, Noriyasu

    2017-12-01

    The coastal areas of the Sea of Japan are a well-known hotspot of winter lightning activity. This study distinguishes between three common types of winter lightning in that region (types A-C), based on their frequency distributions and the meteorological conditions under which they occur. Type A lightning occurs with high frequency in the Tohoku district. It is mainly caused by cold fronts that accompany cyclones passing north of the Japanese islands. Type B, which occurs most frequently in the coastal areas of the Hokuriku district, is mainly caused by topographically induced wind convergence and convective instability, both of which are associated with cyclones having multiple centers. Type C's lightning frequency distribution pattern is similar to that of type B, but its principal cause is a topographically induced wind convergence generated by cold air advection from the Siberian continent. Type A is most frequently observed from October to November, while types B and C tend to appear from November to January, consistent with seasonal changes in lightning frequency distribution in Japan's Tohoku and Hokuriku districts.

  15. Combined effects of food deprivation and food frequency on the amount and temporal distribution of schedule-induced drinking.

    Science.gov (United States)

    Castilla, José Luis; Pellón, Ricardo

    2013-11-01

    Under intermittent food schedules animals develop temporally organized behaviors throughout interfood intervals, with behaviors early in the intervals (interim) normally occurring in excess. Schedule-induced drinking (a prototype of interim, adjunctive behavior) is related to food deprivation and food frequency. This study investigated the interactions that resulted from combining different food-deprivation levels (70%, 80% or 90% free-feeding weights) with different food-occurrence frequencies (15-, 30- or 60-s interfood intervals) in a within-subjects design. Increases in food deprivation and food frequency generally led to increased licking, with greater differences due to food deprivation as interfood intervals became shorter. Distributions of licking were modestly shifted to later in the interfood interval as interfood intervals lengthened, a result that was most marked under 90% food deprivation, which also resulted in flatter distributions. It would therefore appear that food deprivation modulates the licking rate and the distribution of licking in different ways. Effects of food deprivation and food frequency are adequately explained by a theory of adjunctive behavior based on delayed food reinforcement, in contrast to alternative hypotheses. © Society for the Experimental Analysis of Behavior.

  16. Tailoring electron energy distribution functions through energy confinement in dual radio-frequency driven atmospheric pressure plasmas

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, C.; Waskoenig, J. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Gans, T. [Centre for Plasma Physics, School of Maths and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom)

    2012-10-08

    A multi-scale numerical model based on hydrodynamic equations with semi-kinetic treatment of electrons is used to investigate the influence of dual frequency excitation on the effective electron energy distribution function (EEDF) in a radio-frequency driven atmospheric pressure plasma. It is found that variations of power density, voltage ratio, and phase relationship provide separate control over the electron density and the mean electron energy. This is exploited to directly influence both the phase dependent and time averaged effective EEDF. This enables tailoring the EEDF for enhanced control of non-equilibrium plasma chemical kinetics at ambient pressure and temperature.

  17. Coordinated Primary and Secondary Control with Frequency-Bus-Signaling for Distributed Generation and Storage in Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Tang, Fen; Dragicevic, Tomislav

    2013-01-01

    In this paper, a distributed coordinated control scheme based on frequency-bus-signaling (FBS) method for a low-voltage AC three phase microgrid is proposed. The control scheme is composed by two levels. Firstly a primary local control which is different for the DGs and the ESS is proposed. The ESS...... control is implemented to restore the frequency deviation produced by the primary ESS controller while preserving the coordinated control performance. Real-time simulation results show the feasibility of the proposed approach by showing the operation of the microgrid in different scenarios....

  18. Controller design for flexible, distributed parameter mechanical arms via combined state space and frequency domain techniques

    Science.gov (United States)

    Book, W. J.; Majett, M.

    1982-01-01

    The potential benefits of the ability to control more flexible mechanical arms are discussed. A justification is made in terms of speed of movement. A new controller design procedure is then developed to provide this capability. It uses both a frequency domain representation and a state variable representation of the arm model. The frequency domain model is used to update the modal state variable model to insure decoupled states. The technique is applied to a simple example with encouraging results.

  19. Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study.

    Science.gov (United States)

    Hamed, C T; Bollahi, M A; Abdelhamid, I; Med Mahmoud, M A; Ba, B; Ghaber, S; Habti, N; Houmeida, A

    2012-04-01

    There is no data available on the ABO/Rh(D) frequencies in the Mauritanian population. We retrospectively analysed records of a 5-year database that contained ABO/Rh phenotype and ethnic origin of 10 116 volunteers giving blood at the national blood transfusion centre to derive the frequencies of ABO/Rh(D) groups in the Mauritanian population. The two race categories in the country and their sub-ethnic groups: the Moors (whites and black) and the black Africans (Pulhars, Soninkes and Wolof) were included in this study. Globally, group O had the highest frequency (49.10%) followed by A (28.28%), B (18.56%) and AB (4.05%). This order more common in North African populations was found in four of the five ethnic groups composing our population. Allele frequencies were, respectively, 70.20%, 17.74% and 12.04% giving the same order of O > A > B. We observed no significant variation in these frequencies between the different ethnic groups. Rhesus study showed that with a percentage of 94.23% Rh(D) positive is by far the most prevalent, while Rh(D) negative is present only in 5.77% of the total population. This frequency distribution supports the mixed-race composition of the Mauritanian population. © 2011 Blackwell Publishing Ltd.

  20. Innovation in globally distributed teams: the role of LMX, communication frequency, and member influence on team decisions.

    Science.gov (United States)

    Gajendran, Ravi S; Joshi, Aparna

    2012-11-01

    For globally distributed teams charged with innovation, member contributions to the team are crucial for effective performance. Prior research, however, suggests that members of globally distributed teams often feel isolated and excluded from their team's activities and decisions. How can leaders of such teams foster member inclusion in team decisions? Drawing on leader-member exchange (LMX) theory, we propose that for distributed teams, LMX and communication frequency jointly shape member influence on team decisions. Findings from a test of our hypotheses using data from 40 globally distributed teams suggest that LMX can enhance member influence on team decisions when it is sustained through frequent leader-member communication. This joint effect is strengthened as team dispersion increases. At the team level, member influence on team decisions has a positive effect on team innovation. (c) 2012 APA, all rights reserved.

  1. Analytical investigation of response of birefringent fiber Bragg grating sensors in distributed monitoring system based on optical frequency domain reflectometry

    Science.gov (United States)

    Wada, D.; Murayama, H.

    2014-01-01

    When Fiber Bragg gratings (FBGs) are used as strain sensors, both longitudinal and lateral strain can be applied uniformly or non-uniformly over the length of the FBGs. In order for the demodulation of such FBG signal, this paper investigates the response of birefringent FBGs which are monitored by distributed measurement system based on optical frequency domain reflectometry. A numerical model of the distributed measurement system is built based on piece-wise uniform approach, which considers polarization states of propagating lights. The numerical model simulates analytical response of birefringent FBGs especially when birefringence induces power fluctuations in the distributed spectra, which can be noise or new opportunity for sensitive monitoring of birefringence. Simulation results show the relationships between the power fluctuations and the polarization states of the propagating lights. Consequently, appropriate methods of polarization control for sensitive distributed birefringent FBG monitoring are discussed.

  2. Comparison of minute distribution frequency for anesthesia start and end times from an anesthesia information management system and paper records.

    Science.gov (United States)

    Phelps, Michael; Latif, Asad; Thomsen, Robert; Slodzinski, Martin; Raghavan, Rahul; Paul, Sharon Leigh; Stonemetz, Jerry

    2017-08-01

    Use of an anesthesia information management system (AIMS) has been reported to improve accuracy of recorded information. We tested the hypothesis that analyzing the distribution of times charted on paper and computerized records could reveal possible rounding errors, and that this effect could be modulated by differences in the user interface for documenting certain event times with an AIMS. We compared the frequency distribution of start and end times for anesthesia cases completed with paper records and an AIMS. Paper anesthesia records had significantly more times ending with "0" and "5" compared to those from the AIMS (p < 0.001). For case start times, AIMS still exhibited end-digit preference, with times whose last digits had significantly higher frequencies of "0" and "5" than other integers. This effect, however, was attenuated compared to that for paper anesthesia records. For case end times, the distribution of minutes recorded with AIMS was almost evenly distributed, unlike those from paper records that still showed significant end-digit preference. The accuracy of anesthesia case start times and case end times, as inferred by statistical analysis of the distribution of the times, is enhanced with the use of an AIMS. Furthermore, the differences in AIMS user interface for documenting case start and case end times likely affects the degree of end-digit preference, and likely accuracy, of those times.

  3. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrodeless Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    OpenAIRE

    Gavare, Zanda; Revalde, Gita; Skudra, Atis

    2010-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-α diagonal band (d3Πu−→a3∑g+ electronic transition; Q-branch with v=v′=2) to determine the temperature of hydrogen containing high-frequency electrodeless lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied curren...

  4. Fast 2D fluid-analytical simulation of ion energy distributions and electromagnetic effects in multi-frequency capacitive discharges

    Science.gov (United States)

    Kawamura, E.; Lieberman, M. A.; Graves, D. B.

    2014-12-01

    A fast 2D axisymmetric fluid-analytical plasma reactor model using the finite elements simulation tool COMSOL is interfaced with a 1D particle-in-cell (PIC) code to study ion energy distributions (IEDs) in multi-frequency capacitive argon discharges. A bulk fluid plasma model, which solves the time-dependent plasma fluid equations for the ion continuity and electron energy balance, is coupled with an analytical sheath model, which solves for the sheath parameters. The time-independent Helmholtz equation is used to solve for the fields and a gas flow model solves for the steady-state pressure, temperature and velocity of the neutrals. The results of the fluid-analytical model are used as inputs to a PIC simulation of the sheath region of the discharge to obtain the IEDs at the target electrode. Each 2D fluid-analytical-PIC simulation on a moderate 2.2 GHz CPU workstation with 8 GB of memory took about 15-20 min. The multi-frequency 2D fluid-analytical model was compared to 1D PIC simulations of a symmetric parallel-plate discharge, showing good agreement. We also conducted fluid-analytical simulations of a multi-frequency argon capacitively coupled plasma (CCP) with a typical asymmetric reactor geometry at 2/60/162 MHz. The low frequency 2 MHz power controlled the sheath width and sheath voltage while the high frequencies controlled the plasma production. A standing wave was observable at the highest frequency of 162 MHz. We noticed that adding 2 MHz power to a 60 MHz discharge or 162 MHz to a dual frequency 2 MHz/60 MHz discharge can enhance the plasma uniformity. We found that multiple frequencies were not only useful for controlling IEDs but also plasma uniformity in CCP reactors.

  5. Space and phase resolved ion energy and angular distributions in single- and dual-frequency capacitively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States); Moore, Nathaniel; Pribyl, Patrick; Gekelman, Walter [Department of Physics, University of California, Los Angeles, California 90095 (United States)

    2013-11-15

    The control of ion energy and angular distributions (IEADs) is critically important for anisotropic etching or deposition in microelectronic fabrication processes. With single frequency capacitively coupled plasmas (CCPs), the narrowing in angle and spread in energy of ions as they cross the sheath are definable functions of frequency, sheath width, and mean free path. With increases in wafer size, single frequency CCPs are finding difficulty in meeting the requirement of simultaneously controlling plasma densities, ion fluxes, and ion energies. Dual-frequency CCPs are being investigated to provide this flexible control. The high frequency (HF) is intended to control the plasma density and ion fluxes, while the ion energies are intended to be controlled by the low frequency (LF). However, recent research has shown that the LF can also influence the magnitude of ion fluxes and that IEADs are determined by both frequencies. Hence, separate control of fluxes and IEADs is complex. In this paper, results from a two-dimensional computational investigation of Ar/O{sub 2} plasma properties in an industrial reactor are discussed. The IEADs are tracked as a function of height above the substrate and phase within the rf cycles from the bulk plasma to the presheath and through the sheath with the goal of providing insights to this complexity. Comparison is made to laser-induced fluorescence experiments. The authors found that the ratios of HF/LF voltage and driving frequency are critical parameters in determining the shape of the IEADs, both during the transit of the ion through the sheath and when ions are incident onto the substrate. To the degree that contributions from the HF can modify plasma density, sheath potential, and sheath thickness, this may provide additional control for the IEADs.

  6. Deka-keV X-ray observations of solar bursts with WATCH/GRANAT: frequency distributions of burst parameters

    DEFF Research Database (Denmark)

    Crosby, N.; Vilmer, N.; Lund, Niels

    1998-01-01

    be observed as low as 10 keV. A statistical study is performed on the total WATCH solar database and frequency distributions are built on measured X-ray flare parameters. It is also investigated how the properties of these frequency distributions behave when subgroups of events defined by different ranges......Solar flare observations in the deka-keV range are performed by the WATCH experiment on board the GRANAT satellite. The WATCH experiment is presented, including the energy calibration as applied in the present work. The creation of the solar burst catalogue covering two years of observation...... is described and some examples of solar observations are given. The estimated energy releases in the flares presented here are found to extend below the range of hard X-ray flares which were previously studied by ISEE-3 and HXRBS/SMM detectors. The X-ray emitting component cannot be exclusively explained...

  7. Extended parametric gain range in photonic crystal fibers with strongly frequency-dependent field distributions

    DEFF Research Database (Denmark)

    Petersen, Sidsel Rübner; Alkeskjold, Thomas Tanggaard; Olausson, Christina Bjarnal Thulin

    2014-01-01

    The parametric gain range of a degenerate four-wave mixing process is determined in the undepleted pump regime. The gain range is considered with and without taking the mode field distributions of the four-wave mixing components into account. It is found that the mode field distributions have...

  8. Heavy metal distribution frequency in Iranian and imported rice varieties marketed in central Iran, Yazd, 2012

    Directory of Open Access Journals (Sweden)

    Reza Morekian

    2013-01-01

    Full Text Available Aims: This study aimed to determine the concentration of heavy metals including lead (Pb, cadmium (Cd, and arsenic (As in rice samples in Yazd markets. Materials and Methods: In this study, 108 rice samples were collected from 36 different brands including 26 imported and 10 Iranian rice varieties from July-December 2011. Determination of heavy metals was carried out by wet ashing and digestion methods following graphite furnace atomic absorption spectrometry and hydride generation atomic absorption spectrometry. Results: The average concentrations of lead in both Iranian and imported samples were 328.3 ± 81.44 and 254.55 ± 77.2 μg/kg, respectively, well above the safe limit set by Iranian standard, whereas mean concentrations of cadmium and arsenic were both below their permissible limit. In homemade rice samples, their concentration levels were shown to be 37.25 ± 23.39 and 33.5 ± 18.35 μg/kg, respectively. However, for imported products, their levels were 43.71 ± 13.74 and 87.55 ± 72.99 μg/kg, respectively. Conclusion: Deterministic estimation of exposure to heavy metals from rice showed that there was no health issue concerning exposure to toxic metals through rice intake in Iran when potential risk of each heavy metal is considered individually, cumulative risk assessment must be applied in future studies.

  9. Distortions of the distribution function of collisionless particles by high-frequency gravitational waves

    International Nuclear Information System (INIS)

    Vainer, B.V.; Nasel'skii, P.D.

    1983-01-01

    Equations for the correlation functions of fluctuations in the spectra of relativistic collisionless particles are obtained from the combined system of Einstein's equations and the Vlasov equation. It is shown that the interaction of high-frequency gravitational waves with collisionless particles leads to diffusion of their spectrum in the momentum space. The distortions in the spectrum of the microwave background radiation in a cosmological model with high-frequency gravitational waves are discussed. Bounds are obtained on the spectral characteristics of background gravitational waves

  10. Distributed Secondary Voltage and Frequency Control for Islanded Microgrids with Uncertain Communication Links

    DEFF Research Database (Denmark)

    Lu, Xiaoqing; Yu, Xinghuo; Lai, Jingang

    2017-01-01

    energy resources (DERs) in a MG to achieve the voltage/frequency restoration and active power sharing accuracy, respectively. In special, the secondary control inputs are merely updated at the end of each round of iteration, and thus each DER only needs to share information with its neighbors...... theory. The proposed controllers are implemented on local DERs, and thus no central controller is required. Moreover, the desired control objective can also be guaranteed even if all DERs are subject to internal uncertainties and external noises including initial voltage and/or frequency resetting errors...

  11. A combined wave distribution function and stability analysis of Viking particle and low-frequency wave data

    International Nuclear Information System (INIS)

    Oscarsson, T.E.; Roennmark, K.G.

    1990-01-01

    In this paper the authors present an investigation of low-frequency waves observed on auroral field lines below the acceleration region by the Swedish satellite Viking. The measured frequency spectra are peaked at half the local proton gyrofrequency, and the waves are observed in close connection with precipitating electrons. In order to obtain information about the distribution of wave energy in wave vector space, they reconstruct the wave distribution function (WDF) from observed spectral densities. They use a new scheme that allows them to reconstruct simultaneously the WDF over a broad frequency band. The method also makes it possible to take into account available particle observations as well as Doppler shifts caused by the relative motion between the plasma and the satellite. The distribution of energy in wave vector space suggested by the reconstructed WDF is found to be consistent with what is expected from a plasma instability driven by the observed precipitating electrons. Furthermore, by using UV images obtained on Viking, they demonstrate that the wave propagation directions indicated by the reconstructed WDFs are consistent with a simple model of the presumed wave source in the electron precipitation region

  12. Improving Frequency Stability Based on Distributed Control of Multiple Load Aggregators

    DEFF Research Database (Denmark)

    Hu, Jianqiang; Cao, Jinde; Guerrero, Josep M.

    2017-01-01

    into the traditional centralized proportional-integral-based automatic generation control (AGC) framework, which has formed the coupled secondary frequency control structure. It has been shown that the total power mismatch in each control area is shared with both AGC units and load aggregators, and the system...

  13. Radio-frequency properties of stacked long Josephson junctions with nonuniform bias current distribution

    DEFF Research Database (Denmark)

    Filatrella, G; Pedersen, Niels Falsig

    1999-01-01

    We have numerically investigated the behavior of stacks of long Josephson junctions considering a nonuniform bias profile. In the presence of a microwave field the nonuniform bias, which favors the formation of fluxons, can give rise to a change of the sequence of radio-frequency induced steps...

  14. Frequency analysis for planned islanding operation in the Danish distribution system - Bornholm

    DEFF Research Database (Denmark)

    Chen, Yu; Xu, Zhao; Østergaard, Jacob

    2008-01-01

    a planned islanding operation test. To evaluate the test and achieve useful experience for future similar operations in Bornholm or even in other similar systems, the frequency data before, during and after this period, were recorded by Phasor Measurement Units (PMUs), supplied by Centre for Electric...

  15. The frequency and distribution of recent landslides in three montane tropical regions of Puerto Rico

    Science.gov (United States)

    Matthew C. Larsen; Angel J. Torres-Sanchez

    1998-01-01

    Landslides are common in steep mountainous areas of Puerto Rico where mean annual rainfall and the frequency of intense storms are high. Each year, landslides cause extensive damage to property and occasionally result in loss of life. Average population density is high, 422 peoplerkm2, and is increasing. This increase in population density is accompanied by growing...

  16. Genotype distribution and allele frequencies of the genes associated with body composition and locomotion traits in Myanmar native horses.

    Science.gov (United States)

    Okuda, Yu; Moe, Hla Hla; Moe, Kyaw Kyaw; Shimizu, Yuki; Nishioka, Kenji; Shimogiri, Takeshi; Mannen, Hideyuki; Kanemaki, Misao; Kunieda, Tetsuo

    2017-08-01

    Myanmar native horses are small horses used mainly for drafting carts or carriages in rural areas and packing loads in mountainy areas. In the present study, we investigated genotype distributions and allele frequencies of the LCORL/NCAPG, MSTN and DMRT3 genes, which are associated with body composition and locomotion traits of horses, in seven local populations of Myanmar native horses. The genotyping result of LCORL/NCAPG showed that allele frequencies of C allele associated with higher withers height ranged from 0.08 to 0.27, and 0.13 in average. For MSTN, allele frequencies of C allele associated with higher proportion of Type 2B muscular fiber ranged from 0.05 to 0.23, and 0.09 in average. For DMRT3, allele frequencies of A allele associated with ambling gait ranged from 0 to 0.04, and 0.01 in average. The presences of the minor alleles of these genes at low frequencies suggest a possibility that these horse populations have not been under strong selection pressure for particular locomotion traits and body composition. Our findings of the presence of these minor alleles in Southeast Asian native horses are also informative for considering the origins of these minor alleles associated with body composition and locomotion traits in horse populations. © 2016 Japanese Society of Animal Science.

  17. Extended parametric gain range in photonic crystal fibers with strongly frequency-dependent field distributions.

    Science.gov (United States)

    Petersen, Sidsel R; Alkeskjold, Thomas T; Olausson, Christina B; Lægsgaard, Jesper

    2014-08-15

    The parametric gain range of a degenerate four-wave mixing process is determined in the undepleted pump regime. The gain range is considered with and without taking the mode field distributions of the four-wave mixing components into account. It is found that the mode field distributions have to be included to evaluate the parametric gain correctly in dispersion-tailored speciality fibers and that mode profile engineering can provide a way to increase the parametric gain range.

  18. Measurement of Line-to-Ground Capacitance in Distribution Network Considering Magnetizing Impedance’s Frequency Characteristic

    Directory of Open Access Journals (Sweden)

    Qing Yang

    2017-04-01

    Full Text Available Signal injection method (SIM is widely applied to the insulation parameters’ measurement in distribution network for its convenience and safety. It can be divided into two kinds of patterns: injecting a specific frequency signal or several frequencies’ groups, and scanning frequency in a scheduled frequency scope. In order to avoid the disadvantages in related researches, improved signal injection method (ISIM, in which the frequency characteristic of the transformer magnetizing impedance is taken into consideration, is proposed. In addition, optimization for signal injection position has been accomplished, and the corresponding three calculation methods of line-to-ground capacitance has been derived. Calculations are carried out through the vector information (vector calculation method, the amplitude information (amplitude calculation method, the phase information (phase calculation method of voltage and current in signal injecting port, respectively. The line-to-ground capacitance is represented by lumped parameter capacitances in high-voltage simulation test. Eight different sinusoidal signals are injected into zero-sequence circuit, and then line-to-ground capacitance is calculated with the above-mentioned vector calculation method based on the voltage and the current data of the injecting port. The results obtained by the vector calculation method show that ISIM has a wider application frequency range compared with signal injection method with rated parameters (RSIM and SIM. The RSIM is calculated with the rated transformer parameters of magnetizing impedance, and the SIM based on the ideal transformer model, and the relative errors of calculation results of ISIM are smaller than that for other methods in general. The six groups of two-frequency set are chosen in a specific scope which is recommended by vector calculation results. Based on ISIM, the line-to-ground capacitance calculations through the amplitude calculation method and

  19. Mutation Rate Variation is a Primary Determinant of the Distribution of Allele Frequencies in Humans.

    Directory of Open Access Journals (Sweden)

    Arbel Harpak

    2016-12-01

    Full Text Available The site frequency spectrum (SFS has long been used to study demographic history and natural selection. Here, we extend this summary by examining the SFS conditional on the alleles found at the same site in other species. We refer to this extension as the "phylogenetically-conditioned SFS" or cSFS. Using recent large-sample data from the Exome Aggregation Consortium (ExAC, combined with primate genome sequences, we find that human variants that occurred independently in closely related primate lineages are at higher frequencies in humans than variants with parallel substitutions in more distant primates. We show that this effect is largely due to sites with elevated mutation rates causing significant departures from the widely-used infinite sites mutation model. Our analysis also suggests substantial variation in mutation rates even among mutations involving the same nucleotide changes. In summary, we show that variable mutation rates are key determinants of the SFS in humans.

  20. Joint accurate time and stable frequency distribution infrastructure sharing fiber footprint with research network

    Czech Academy of Sciences Publication Activity Database

    Vojtěch, J.; Šlapák, M.; Škoda, P.; Radil, J.; Havliš, O.; Altmann, M.; Münster, P.; Velč, R.; Kundrát, J.; Altmannová, L.; Vohnout, R.; Horváth, T.; Hůla, M.; Smotlacha, V.; Čížek, Martin; Pravdová, Lenka; Řeřucha, Šimon; Hrabina, Jan; Číp, Ondřej

    2017-01-01

    Roč. 56, č. 2 (2017), s. 1-7, č. článku 027101. ISSN 0091-3286 R&D Projects: GA ČR GB14-36681G Institutional support: RVO:68081731 Keywords : accurate time * stable frequency * wavelength division multiplexing * bidirectional reciprocal path * Sagnac effect Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 1.082, year: 2016

  1. A High Performance Frequency Standard and Distribution System for Cassini Ka-Band Experiment

    Science.gov (United States)

    2005-08-01

    Orthogonal Polarization In Anisotropic Dielectric Resonators”, Proceedings of the 2002 IEEE International Frequency Control Symposium , pp. 553-558...2002. [9] G. J. Dick, Rabi T. Wang, Robert Tjoelker, “Design and Progress Report for Compact Cryocooled Sapphire Oscillator "VCSO"”, Proc. 2005 Joint...IEEE FCS/ PTTI. [10] R. Basu, G. J. Dick, Rabi T. Wang,” Novel Design of an All- Cryogenic RF Pound Circuit “,Proc. 2005 Joint IEEE FCS/ PTTI

  2. Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones

    International Nuclear Information System (INIS)

    Gosselin, Marie-Christine; Kühn, Sven; Kuster, Niels

    2013-01-01

    The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., −16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system. (paper)

  3. Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones

    Science.gov (United States)

    Gosselin, Marie-Christine; Kühn, Sven; Kuster, Niels

    2013-12-01

    The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., -16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system.

  4. Hydrological model calibration for derived flood frequency analysis using stochastic rainfall and probability distributions of peak flows

    Science.gov (United States)

    Haberlandt, U.; Radtke, I.

    2014-01-01

    Derived flood frequency analysis allows the estimation of design floods with hydrological modeling for poorly observed basins considering change and taking into account flood protection measures. There are several possible choices regarding precipitation input, discharge output and consequently the calibration of the model. The objective of this study is to compare different calibration strategies for a hydrological model considering various types of rainfall input and runoff output data sets and to propose the most suitable approach. Event based and continuous, observed hourly rainfall data as well as disaggregated daily rainfall and stochastically generated hourly rainfall data are used as input for the model. As output, short hourly and longer daily continuous flow time series as well as probability distributions of annual maximum peak flow series are employed. The performance of the strategies is evaluated using the obtained different model parameter sets for continuous simulation of discharge in an independent validation period and by comparing the model derived flood frequency distributions with the observed one. The investigations are carried out for three mesoscale catchments in northern Germany with the hydrological model HEC-HMS (Hydrologic Engineering Center's Hydrologic Modeling System). The results show that (I) the same type of precipitation input data should be used for calibration and application of the hydrological model, (II) a model calibrated using a small sample of extreme values works quite well for the simulation of continuous time series with moderate length but not vice versa, and (III) the best performance with small uncertainty is obtained when stochastic precipitation data and the observed probability distribution of peak flows are used for model calibration. This outcome suggests to calibrate a hydrological model directly on probability distributions of observed peak flows using stochastic rainfall as input if its purpose is the

  5. Agent based Particle Swarm Optimization for Load Frequency Control of Distribution Grid

    DEFF Research Database (Denmark)

    Cha, Seung-Tae; Saleem, Arshad; Wu, Qiuwei

    2012-01-01

    This paper presents a Particle Swarm Optimization (PSO) based on multi-agent controller. Real-time digital simulator (RTDS) is used for modelling the power system, while a PSO based multi-agent LFC algorithm is developed in JAVA for communicating with resource agents and determines the scenario...... to stabilize the frequency and voltage after the system enters into the islanding operation mode. The proposed algorithm is based on the formulation of an optimization problem using agent based PSO. The modified IEEE 9-bus system is employed to illustrate the performance of the proposed controller via RTDS...

  6. On the distribution of the frequency of stellar flares in stellar aggregates

    International Nuclear Information System (INIS)

    Mnatsakanyan, M.A.

    1986-01-01

    The analytic time-representation of the multiplicity of flares in stellar aggregates based on observational data at present is given under the condition of independency of flares from each other. They are exactly approximated by two ''Poisson'' groups with stars in each of them having the same frequency: N 1 =670, ν 1 =1.1 flares at all observational time, N 2 =60, ν 2 =9 - for Pleiades, and by one Poisson process with N=1250, ν=0.49 - for Orion, N=330, ν=0.37 - for the Dark Nebulae of Taurus. The total number of fkare stars in the Pleiades is nearly equal or less than 750

  7. Cumulative risk, cumulative outcome: a 20-year longitudinal study.

    Directory of Open Access Journals (Sweden)

    Leslie Atkinson

    Full Text Available Cumulative risk (CR models provide some of the most robust findings in the developmental literature, predicting numerous and varied outcomes. Typically, however, these outcomes are predicted one at a time, across different samples, using concurrent designs, longitudinal designs of short duration, or retrospective designs. We predicted that a single CR index, applied within a single sample, would prospectively predict diverse outcomes, i.e., depression, intelligence, school dropout, arrest, smoking, and physical disease from childhood to adulthood. Further, we predicted that number of risk factors would predict number of adverse outcomes (cumulative outcome; CO. We also predicted that early CR (assessed at age 5/6 explains variance in CO above and beyond that explained by subsequent risk (assessed at ages 12/13 and 19/20. The sample consisted of 284 individuals, 48% of whom were diagnosed with a speech/language disorder. Cumulative risk, assessed at 5/6-, 12/13-, and 19/20-years-old, predicted aforementioned outcomes at age 25/26 in every instance. Furthermore, number of risk factors was positively associated with number of negative outcomes. Finally, early risk accounted for variance beyond that explained by later risk in the prediction of CO. We discuss these findings in terms of five criteria posed by these data, positing a "mediated net of adversity" model, suggesting that CR may increase some central integrative factor, simultaneously augmenting risk across cognitive, quality of life, psychiatric and physical health outcomes.

  8. Assessing variation in skeletal production from surface death assemblages on the basis of age-frequency distributions

    Science.gov (United States)

    Tomasovych, Adam; Kidwell, Susan M.; Foygel Barber, Rina

    2015-04-01

    Age-frequency distributions of dead skeletal material that capture information on the elapsed time since death of individuals on the landscape or seabed provide decadal- to millennial-scale windows into the history of production and on the processes that lead to skeletal disintegration and burial. However, models quantifying the dynamics of skeletal loss assumed that skeletal production has been constant during accumulation of death assemblages. Here, we assess the joint effects of temporally-variable production and skeletal loss on the shape of postmortem age-frequency distributions. We show that the modes of such distributions will tend to be shifted to younger age cohorts relative to the true timing of past production pulses. This shift in the timing of a past production will be higher where loss rates are high and/or the rate of decline in production is slow. We apply the models combining the dynamic of loss and production to death assemblages with the deposit-feeding bivalve Nuculana taphria from the Southern California continental shelf, finding that (1) an onshore-offshore gradient in time averaging is dominated by a gradient in the timing of production, corresponding to the tracking of shallow-water habitats under a sea-level rise, and (2) model estimates of the timing of past production are in good agreement with an independent sea-level curve.

  9. Self-induced frequency scanning and distributed Bragg reflection in semiconductor lasers with phase-conjugate feedback

    Energy Technology Data Exchange (ETDEWEB)

    Cronin-Golomb; Yariv

    1986-07-01

    A GaA1As semiconductor laser with feedback from a barium titanate photorefractive ring passive phase-conjugate mirror can be made to perform repeating or nonrepeating frequency scans over a 10-nm range toward either the blue or the red. The direction of scanning and whether the scans repeat may be controlled by adjusting the overlap of the interaction beams in the crystal. This overlap region may be adjusted so that the diode frequency spectrum, originally occupying about 10 longitudinal modes, scans and narrows as the conjugate signal builds up, coming to rest often in one, but sometimes two or three, longitudinal modes as a result of self-generated distributed-feedback effects. Also reported similar effects caused by feedback from the total-internal-reflection passive phase-conjugate mirror. The alignment-control mechanism of the ring mirror is, however, not available in this case.

  10. Self-induced frequency scanning and distributed Bragg reflection in semiconductor lasers with phase-conjugate feedback

    Energy Technology Data Exchange (ETDEWEB)

    Cronin-Golomb, M.; Yariv, A.

    1986-07-01

    A GaAlAs semiconductor laser with feedback from a barium titanate photorefractive ring passive phase-conjugate mirror can be made to perform repeating or nonrepeating frequency scans over a 10-nm range toward either the blue or the red. The direction of scanning and whether the scans repeat may be controlled by adjusting the overlap of the interaction beams in the crystal. This overlap region may be adjusted so that the diode frequency spectrum, originally occupying about 10 longitudinal modes, scans and narrows as the conjugate signal builds up, coming to rest often in one, but sometimes two or three, longitudinal modes as a result of self-generated distributed-feedback effects. We also report similar effects caused by feedback from the total-internal-reflection passive phase-conjugate mirror. The alignment-control mechanism of the ring mirror is, however, not available in this case.

  11. Self-induced frequency scanning and distributed bragg reflection in semiconductor lasers with phase-conjugate feedback

    Science.gov (United States)

    Cronin-Golomb, Mark; Yariv, Amnon

    1986-07-01

    A GaAlAs semiconductor laser with feedback from a barium titanate photorefractive ring passive phase-conjugate mirror can be made to perform repeating or nonrepeating frequency scans over a 10-nm range toward either the blue or the red. The direction of scanning and whether the scans repeat may be controlled by adjusting the overlap of the interaction beams in the crystal. This overlap region may be adjusted so that the diode frequency spectrum, originally occupying about 10 longitudinal modes, scans and narrows as the conjugate signal builds up, coming to rest often in one, but sometimes two or three, longitudinal modes as a result of self-generated distributed-feedback effects. We also report similar effects caused by feedback from the total-internal-reflection passive phase-conjugate mirror. The alignment-control mechanism of the ring mirror is, however, not available in this case.

  12. Investigation of the interpolation method to improve the distributed strain measurement accuracy in optical frequency domain reflectometry systems.

    Science.gov (United States)

    Cui, Jiwen; Zhao, Shiyuan; Yang, Di; Ding, Zhenyang

    2018-02-20

    We use a spectrum interpolation technique to improve the distributed strain measurement accuracy in a Rayleigh-scatter-based optical frequency domain reflectometry sensing system. We demonstrate that strain accuracy is not limited by the "uncertainty principle" that exists in the time-frequency analysis. Different interpolation methods are investigated and used to improve the accuracy of peak position of the cross-correlation and, therefore, improve the accuracy of the strain. Interpolation implemented by padding zeros on one side of the windowed data in the spatial domain, before the inverse fast Fourier transform, is found to have the best accuracy. Using this method, the strain accuracy and resolution are both improved without decreasing the spatial resolution. The strain of 3 μϵ within the spatial resolution of 1 cm at the position of 21.4 m is distinguished, and the measurement uncertainty is 3.3 μϵ.

  13. Allele frequency distribution for 15 autosomal STR loci in Afridi Pathan population of Uttar Pradesh, India.

    Science.gov (United States)

    Noor, Sabahat; Ali, Shahnaz; Eaaswarkhanth, Muthukrishnan; Haque, Ikramul

    2009-11-01

    Allele frequencies of the 15 autosomal short tandem repeat (STR) loci D8S1179, D21S11, D7S820, CSF1PO D19S433, vWA, TPOX, D18S51, D3S1358, THO1, D13S317, D16S539, D2S1338, D5S818 and FGA were determined in Afridi Pathan population of Uttar Pradesh, India. All the 15 STR loci studied were found to be highly polymorphic with respect to observed heterozygosity values. Adherence to the expectations of the Hardy-Weinberg equilibrium (HWE) was confirmed for all the loci with an exception of TPOX and FGA. The allele 12 in CSF1PO was found to be most frequent. The power of discrimination was found to be high ranging from a minimum of 0.858 for the locus CSFIPO to maximum of 0.962 for the locus FGA, thereby facilitating the validation and efficiency of these STR markers in human identification. Population differentiation test between the studied and neighboring populations revealed significant differences at several loci suggesting the endogamous nature of the studied population. To the best of our knowledge, Afridi Pathan population has not been explored genetically for generating forensic data on STR markers. Therefore, STR allele frequency data of this unique population is a valuable contribution to the existing DNA database on Indian populations.

  14. Inference for Local Distributions at High Sampling Frequencies: A Bootstrap Approach

    DEFF Research Database (Denmark)

    Hounyo, Ulrich; Varneskov, Rasmus T.

    of "large" jumps. Our locally dependent wild bootstrap (LDWB) accommodate issues related to the stochastic scale and jumps as well as account for a special block-wise dependence structure induced by sampling errors. We show that the LDWB replicates first and second-order limit theory from the usual...... empirical process and the stochastic scale estimate, respectively, as well as an asymptotic bias. Moreover, we design the LDWB sufficiently general to establish asymptotic equivalence between it and and a nonparametric local block bootstrap, also introduced here, up to second-order distribution theory....... Finally, we introduce LDWB-aided Kolmogorov-Smirnov tests for local Gaussianity as well as local von-Mises statistics, with and without bootstrap inference, and establish their asymptotic validity using the second-order distribution theory. The finite sample performance of CLT and LDWB-aided local...

  15. 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...

  16. Reconsidering the smart metering data collection frequency for distribution state estimation

    OpenAIRE

    Chen, Qipeng; Kaleshi, Dritan; Armour, Simon; Fan, Zhong

    2015-01-01

    The current UK Smart Metering Technical Specification requires smart meter readings to be collected once a day, primarily to support accurate billing without violating users' privacy. In this paper we consider the use of Smart Metering data for Distribution State Estimation (DSE), and compare the effectiveness of daily data collection strategy with a more frequent, half-hourly SM data collection strategy. We first assess the suitability of using the data for load forecasting at Low Voltage (L...

  17. Bubble size distribution analysis and control in high frequency ultrasonic cleaning processes

    International Nuclear Information System (INIS)

    Hauptmann, M; Struyf, H; Mertens, P; Heyns, M; Gendt, S De; Brems, S; Glorieux, C

    2012-01-01

    In the semiconductor industry, the ongoing down-scaling of nanoelectronic elements has lead to an increasing complexity of their fabrication. Hence, the individual fabrication processes become increasingly difficult to handle. To minimize cross-contamination, intermediate surface cleaning and preparation steps are inevitable parts of the semiconductor process chain. Here, one major challenge is the removal of residual nano-particulate contamination resulting from abrasive processes such as polishing and etching. In the past, physical cleaning techniques such as megasonic cleaning have been proposed as suitable solutions. However, the soaring fragility of the smallest structures is constraining the forces of the involved physical removal mechanisms. In the case of 'megasonic' cleaning –cleaning with ultrasound in the MHz-domain – the main cleaning action arises from strongly oscillating microbubbles which emerge from the periodically changing tensile strain in the cleaning liquid during sonication. These bubbles grow, oscillate and collapse due to a complex interplay of rectified diffusion, bubble coalescence, non-linear pulsation and the onset of shape instabilities. Hence, the resulting bubble size distribution does not remain static but alternates continuously. Only microbubbles in this distribution that show a high oscillatory response are responsible for the cleaning action. Therefore, the cleaning process efficiency can be improved by keeping the majority of bubbles around their resonance size. In this paper, we propose a method to control and characterize the bubble size distribution by means of 'pulsed' sonication and measurements of acoustic cavitation spectra, respectively. We show that the so-obtained bubble size distributions can be related to theoretical predictions of the oscillatory responses of and the onset of shape instabilities for the respective bubbles. We also propose a mechanism to explain the enhancement of both acoustic and cleaning

  18. Category effects on stimulus estimation: Shifting and skewed frequency distributions-A reexamination.

    Science.gov (United States)

    Duffy, Sean; Smith, John

    2017-10-18

    Duffy, Huttenlocher, Hedges, and Crawford (Psychonomic Bulletin & Review, 17(2), 224-230, 2010) report on experiments where participants estimate the lengths of lines. These studies were designed to test the category adjustment model (CAM), a Bayesian model of judgments. The authors report that their analysis provides evidence consistent with CAM: that there is a bias toward the running mean and not recent stimuli. We reexamine their data. First, we attempt to replicate their analysis, and we obtain different results. Second, we conduct a different statistical analysis. We find significant recency effects, and we identify several specifications where the running mean is not significantly related to judgment. Third, we conduct tests of auxiliary predictions of CAM. We do not find evidence that the bias toward the mean increases with exposure to the distribution. We also do not find that responses longer than the maximum of the distribution or shorter than the minimum become less likely with greater exposure to the distribution. Fourth, we produce a simulated dataset that is consistent with key features of CAM, and our methods correctly identify it as consistent with CAM. We conclude that the Duffy et al. (2010) dataset is not consistent with CAM. We also discuss how conventions in psychology do not sufficiently reduce the likelihood of these mistakes in future research. We hope that the methods that we employ will be used to evaluate other datasets.

  19. Frequency of legionella contamination in conditional & water distribution systems of Tehran hospitals

    Directory of Open Access Journals (Sweden)

    Davod Esmaieli

    2008-09-01

    Full Text Available Background: Legionella species are ubiquitous in natural aquatic environments, capable of existing in waters with varied temperatures, PH levels, and nutrient and oxygen contents. Of 49 known legionella species, 20 species have been linked to pneumonia in humans. Contamination by legionella has occurred in the distribution systems of many hospitals. Aerosol-generating systems such as faucets, showerheads, cooling towers, and nebulizers are responsible for their transmission from water to air. Methods: A total of 113 water samples were gathered from different wards of 32 hospitals in different geographical regions of Tehran city. These samples were concentrated by filtration, treated with the acid and temperature buffers, and isolated on a BCYE agar culture medium. Results: A total of 22 hospitals out of 33 (26.5% were contaminated by legionella species, and 30 samples (26.5% out of 113 were positive. Chlorine concentration and pH level of the water samples were 0.18-2.2 mg/l and 6.6-7.6, respectively. Conclusion: The high rate of waste water contamination in Tehran hospitals with Legionella indicates the resistance of this microorganism to chlorine and other disinfectants, or inadequate disinfection process, representing the insufficiency of the current decontamination of hospital water distribution system. Thus identifying legionella species and their controlling in water distribution system of hospitals is of great importance.

  20. Allele frequency distribution of D8S592 (STR) and PDGFA (VNTR) among five endogamous population groups of India.

    Science.gov (United States)

    Ahmad, Shazia; Seshadri, M

    2004-07-01

    Allele frequency distribution have been analyzed at D8S592 (short tandem repeat) and PDGFA (variable number of tandem repeat) among five distinct endogamous groups of India namely Ezhavas, Nayers, Arayas, Vishwakarma and Muslims. Muslims are religio-ethnic group while other populations mentioned above belong to distinct section of Hindu religion. All these populations are from Kollam district of Kerala in Southern India and speak Malayalam, an Indo-Dravidian language. A total of 228 for D8S592 and 212 for PDGFA loci, random, healthy individuals were analyzed.

  1. Observation and simulation of space-charge effects in a radio-frequency photoinjector using a transverse multibeamlet distribution

    Directory of Open Access Journals (Sweden)

    M. Rihaoui

    2009-12-01

    Full Text Available We report on an experimental study of space-charge effects in a radio-frequency (rf photoinjector. A 5 MeV electron bunch, consisting of a number of beamlets separated transversely, was generated in an rf photocathode gun and propagated in the succeeding drift space. The collective interaction of these beamlets was studied for different experimental conditions. The experiment allowed the exploration of space-charge effects and its comparison with 3D particle-in-cell simulations. Our observations also suggest the possible use of a multibeam configuration to tailor the transverse distribution of an electron beam.

  2. Mapping closure for probability distribution function in low frequency magnetized plasma turbulence

    International Nuclear Information System (INIS)

    Das, A.; Kaw, P.

    1995-01-01

    Recent numerical studies on the Hasegawa--Mima equation and its variants describing low frequency magnetized plasma turbulence indicate that the potential fluctuations have a Gaussian character whereas the vorticity exhibits non-Gaussian features. A theoretical interpretation for this observation using the recently developed mapping closure technique [Chen, Chen, and Kraichnan, Phys. Rev. Lett. 63, 2657 (1989)] has been provided here. It has been shown that non-Gaussian statistics for the vorticity arises because of a competition between nonlinear straining and diffusive damping whereas the Gaussianity of the statistics of φ arises because the only significant nonlinearity is associated with divergence free convection, which produces no strain terms. copyright 1995 American Institute of Physics

  3. Using radio frequency and ultrasonic antennas for inspecting pin-type insulators on medium-voltage overhead distribution lines

    Directory of Open Access Journals (Sweden)

    Cícero Lefort Borges

    2013-05-01

    Full Text Available This paper summarises the activities undertaken when using antennas (ultrasound and radiofrequency for identifying insulators in pre-failure state by detecting the noise emitted by the distribution line and correlating this with these insulators (porcelain pin type dielectric breakdown. This has led to developing low-cost maintenance procedures and providing support and criteria for engineer-ing decisions regarding replacing these insulators. The technique used two detectors; a radio frequency detector was used in a first investigation of a particular distribution line, set to 40 MHz and installed on the roof of a moving vehicle. The ultrasound detector was used for inspecting (phases A, B, C each structure (pole selected. Atmospheric conditions had no influence on defining pre-failure insulators (pin type based on the noise detection technique. Pin type insulators emitting noise should be replaced since measurement was made from the ground and near the base of the post.

  4. Improved high-frequency equivalent circuit model based on distributed effects for SiGe HBTs with CBE layout

    International Nuclear Information System (INIS)

    Sun Ya-Bin; Li Xiao-Jin; Zhang Jin-Zhong; Shi Yan-Ling

    2017-01-01

    In this paper, we present an improved high-frequency equivalent circuit for SiGe heterojunction bipolar transistors (HBTs) with a CBE layout, where we consider the distributed effects along the base region. The actual device structure is divided into three parts: a link base region under a spacer oxide, an intrinsic transistor region under the emitter window, and an extrinsic base region. Each region is considered as a two-port network, and is composed of a distributed resistance and capacitance. We solve the admittance parameters by solving the transmission-line equation. Then, we obtain the small-signal equivalent circuit depending on the reasonable approximations. Unlike previous compact models, in our proposed model, we introduce an additional internal base node, and the intrinsic base resistance is shifted into this internal base node, which can theoretically explain the anomalous change in the intrinsic bias-dependent collector resistance in the conventional compact model. (paper)

  5. Use of critical pathway models and log-normal frequency distributions for siting nuclear facilities

    International Nuclear Information System (INIS)

    Waite, D.A.; Denham, D.H.

    1975-01-01

    The advantages and disadvantages of potential sites for nuclear facilities are evaluated through the use of environmental pathway and log-normal distribution analysis. Environmental considerations of nuclear facility siting are necessarily geared to the identification of media believed to be sifnificant in terms of dose to man or to be potential centres for long-term accumulation of contaminants. To aid in meeting the scope and purpose of this identification, an exposure pathway diagram must be developed. This type of diagram helps to locate pertinent environmental media, points of expected long-term contaminant accumulation, and points of population/contaminant interface for both radioactive and non-radioactive contaminants. Confirmation of facility siting conclusions drawn from pathway considerations must usually be derived from an investigatory environmental surveillance programme. Battelle's experience with environmental surveillance data interpretation using log-normal techniques indicates that this distribution has much to offer in the planning, execution and analysis phases of such a programme. How these basic principles apply to the actual siting of a nuclear facility is demonstrated for a centrifuge-type uranium enrichment facility as an example. A model facility is examined to the extent of available data in terms of potential contaminants and facility general environmental needs. A critical exposure pathway diagram is developed to the point of prescribing the characteristics of an optimum site for such a facility. Possible necessary deviations from climatic constraints are reviewed and reconciled with conclusions drawn from the exposure pathway analysis. Details of log-normal distribution analysis techniques are presented, with examples of environmental surveillance data to illustrate data manipulation techniques and interpretation procedures as they affect the investigatory environmental surveillance programme. Appropriate consideration is given these

  6. Variation in recombination frequency and distribution across eukaryotes: patterns and processes

    Science.gov (United States)

    Feulner, Philine G. D.; Johnston, Susan E.; Santure, Anna W.; Smadja, Carole M.

    2017-01-01

    Recombination, the exchange of DNA between maternal and paternal chromosomes during meiosis, is an essential feature of sexual reproduction in nearly all multicellular organisms. While the role of recombination in the evolution of sex has received theoretical and empirical attention, less is known about how recombination rate itself evolves and what influence this has on evolutionary processes within sexually reproducing organisms. Here, we explore the patterns of, and processes governing recombination in eukaryotes. We summarize patterns of variation, integrating current knowledge with an analysis of linkage map data in 353 organisms. We then discuss proximate and ultimate processes governing recombination rate variation and consider how these influence evolutionary processes. Genome-wide recombination rates (cM/Mb) can vary more than tenfold across eukaryotes, and there is large variation in the distribution of recombination events across closely related taxa, populations and individuals. We discuss how variation in rate and distribution relates to genome architecture, genetic and epigenetic mechanisms, sex, environmental perturbations and variable selective pressures. There has been great progress in determining the molecular mechanisms governing recombination, and with the continued development of new modelling and empirical approaches, there is now also great opportunity to further our understanding of how and why recombination rate varies. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109219

  7. No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls.

    Science.gov (United States)

    Li, Li; Xiong, De-fu; Liu, Jia-wen; Li, Zi-xin; Zeng, Guang-cheng; Li, Hua-liang

    2014-03-01

    We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.

  8. In-plane modal frequencies and mode shapes of two stay cables interconnected by uniformly distributed cross-ties

    Science.gov (United States)

    Jing, Haiquan; He, Xuhui; Zou, Yunfeng; Wang, Hanfeng

    2018-03-01

    Stay cables are important load-bearing structural elements of cable-stayed bridges. Suppressing the large vibrations of the stay cables under the external excitations is of worldwide concern for the bridge engineers and researchers. Over the past decade, the use of crosstie has become one of the most practical and effective methods. Extensive research has led to a better understanding of the mechanics of cable networks, and the effects of different parameters, such as length ratio, mass-tension ratio, and segment ratio on the effectiveness of the crosstie have been investigated. In this study, uniformly distributed elastic crossties serve to replace the traditional single, or several cross-ties, aiming to delay "mode localization." A numerical method is developed by replacing the uniformly distributed, discrete elastic cross-tie model with an equivalent, continuously distributed, elastic cross-tie model in order to calculate the modal frequencies and mode shapes of the cable-crosstie system. The effectiveness of the proposed method is verified by comparing the elicited results with those obtained using the previous method. The uniformly distributed elastic cross-ties are shown to significantly delay "mode localization."

  9. Changes in chromosome aberration frequency in Chinese hamster liver related to LET and microdose distribution

    International Nuclear Information System (INIS)

    Brooks, A.L.; McClellan, R.O.

    1976-01-01

    The effect of radiation quality on the frequency of chromosome aberrations in liver cells was determined by exposing animals to either 60 Co gamma irradiation as a reference standard or to radionuclides that deposit in liver; 144 Ce, a beta emitter, 238 Pu, 239 Pu and 241 Am, alpha emitters, and 252 Cf, an isotope which emits alpha, fission fragments, neutrons, and gamma rays. All the radionuclides were injected as the citrate which resulted in a large fraction of their total activity being deposited in the liver. With the exception of acute gamma exposure, all dose response relationships could be adequately described by a linear equation. Quality factors for the different LET exposures were derived by comparing the slopes of the dose response curves. Using protracted 60 Co exposures as the reference, the quality factor for the beta emitter 144 Ce- 144 Pr is 1. Quality factors for the alpha emitters 238 Pu, 239 Pu and 241 Am ranged from 11 to 20 which seems to be higher than the value of 10 used in establishing radiation protection standards. The factor derived for 252 Cf was 10. The lower quality factor compared to pure alpha emitters was attributed to the ineffectiveness of fission fragments in producing measurable chromosome damage

  10. Assessment of landslide distribution map reliability in Niigata prefecture - Japan using frequency ratio approach

    Science.gov (United States)

    Rahardianto, Trias; Saputra, Aditya; Gomez, Christopher

    2017-07-01

    Research on landslide susceptibility has evolved rapidly over the few last decades thanks to the availability of large databases. Landslide research used to be focused on discreet events but the usage of large inventory dataset has become a central pillar of landslide susceptibility, hazard, and risk assessment. Indeed, extracting meaningful information from the large database is now at the forth of geoscientific research, following the big-data research trend. Indeed, the more comprehensive information of the past landslide available in a particular area is, the better the produced map will be, in order to support the effective decision making, planning, and engineering practice. The landslide inventory data which is freely accessible online gives an opportunity for many researchers and decision makers to prevent casualties and economic loss caused by future landslides. This data is advantageous especially for areas with poor landslide historical data. Since the construction criteria of landslide inventory map and its quality evaluation remain poorly defined, the assessment of open source landslide inventory map reliability is required. The present contribution aims to assess the reliability of open-source landslide inventory data based on the particular topographical setting of the observed area in Niigata prefecture, Japan. Geographic Information System (GIS) platform and statistical approach are applied to analyze the data. Frequency ratio method is utilized to model and assess the landslide map. The outcomes of the generated model showed unsatisfactory results with AUC value of 0.603 indicate the low prediction accuracy and unreliability of the model.

  11. High resolution, high sensitivity, dynamic distributed structural monitoring using optical frequency domain reflectometry

    Science.gov (United States)

    Kreger, Stephen T.; Sang, Alex K.; Garg, Naman; Michel, Julia

    2013-05-01

    Fiber-optic ultrasonic transducers are an important component of an active ultrasonic testing system for structural health monitoring. Fiber-optic transducers have several advantages such as small size, light weight, and immunity to electromagnetic interference that make them much more attractive than the current available piezoelectric transducers, especially as embedded and permanent transducers in active ultrasonic testing for structural health monitoring. In this paper, a distributed fiber-optic laser-ultrasound generation based on the ghost-mode of tilted fiber Bragg gratings is studied. The influences of the laser power and laser pulse duration on the laser-ultrasound generation are investigated. The results of this paper are helpful to understand the working principle of this laser-ultrasound method and improve the ultrasonic generation efficiency.

  12. Order-disorder transition in conflicting dynamics leading to rank-frequency generalized beta distributions

    Science.gov (United States)

    Alvarez-Martinez, R.; Martinez-Mekler, G.; Cocho, G.

    2011-01-01

    The behavior of rank-ordered distributions of phenomena present in a variety of fields such as biology, sociology, linguistics, finance and geophysics has been a matter of intense research. Often power laws have been encountered; however, their validity tends to hold mainly for an intermediate range of rank values. In a recent publication (Martínez-Mekler et al., 2009 [7]), a generalization of the functional form of the beta distribution has been shown to give excellent fits for many systems of very diverse nature, valid for the whole range of rank values, regardless of whether or not a power law behavior has been previously suggested. Here we give some insight on the significance of the two free parameters which appear as exponents in the functional form, by looking into discrete probabilistic branching processes with conflicting dynamics. We analyze a variety of realizations of these so-called expansion-modification models first introduced by Wentian Li (1989) [10]. We focus our attention on an order-disorder transition we encounter as we vary the modification probability p. We characterize this transition by means of the fitting parameters. Our numerical studies show that one of the fitting exponents is related to the presence of long-range correlations exhibited by power spectrum scale invariance, while the other registers the effect of disordering elements leading to a breakdown of these properties. In the absence of long-range correlations, this parameter is sensitive to the occurrence of unlikely events. We also introduce an approximate calculation scheme that relates this dynamics to multinomial multiplicative processes. A better understanding through these models of the meaning of the generalized beta-fitting exponents may contribute to their potential for identifying and characterizing universality classes.

  13. Frequency Distribution of Second Solid Cancer Locations in Relation to the Irradiated Volume Among 115 Patients Treated for Childhood Cancer

    International Nuclear Information System (INIS)

    Diallo, Ibrahima; Haddy, Nadia; Adjadj, Elisabeth; Samand, Akhtar; Quiniou, Eric; Chavaudra, Jean; Alziar, Iannis; Perret, Nathalie; Guerin, Sylvie; Lefkopoulos, Dimitri; Vathaire, Florent de

    2009-01-01

    Purpose: To provide better estimates of the frequency distribution of second malignant neoplasm (SMN) sites in relation to previous irradiated volumes, and better estimates of the doses delivered to these sites during radiotherapy (RT) of the first malignant neoplasm (FMN). Methods and Materials: The study focused on 115 patients who developed a solid SMN among a cohort of 4581 individuals. The homemade software package Dos E G was used to estimate the radiation doses delivered to SMN sites during RT of the FMN. Three-dimensional geometry was used to evaluate the distances between the irradiated volume, for RT delivered to each FMN, and the site of the subsequent SMN. Results: The spatial distribution of SMN relative to the irradiated volumes in our cohort was as follows: 12% in the central area of the irradiated volume, which corresponds to the planning target volume (PTV), 66% in the beam-bordering region (i.e., the area surrounding the PTV), and 22% in regions located more than 5 cm from the irradiated volume. At the SMN site, all dose levels ranging from almost zero to >75 Gy were represented. A peak SMN frequency of approximately 31% was identified in volumes that received <2.5 Gy. Conclusion: A greater volume of tissues receives low or intermediate doses in regions bordering the irradiated volume with modern multiple-beam RT arrangements. These results should be considered for risk-benefit evaluations of RT.

  14. High frequency seismic signal generated by landslides on complex topographies: from point source to spatially distributed sources

    Science.gov (United States)

    Mangeney, A.; Kuehnert, J.; Capdeville, Y.; Durand, V.; Stutzmann, E.; Kone, E. H.; Sethi, S.

    2017-12-01

    During their flow along the topography, landslides generate seismic waves in a wide frequency range. These so called landquakes can be recorded at very large distances (a few hundreds of km for large landslides). The recorded signals depend on the landslide seismic source and the seismic wave propagation. If the wave propagation is well understood, the seismic signals can be inverted for the seismic source and thus can be used to get information on the landslide properties and dynamics. Analysis and modeling of long period seismic signals (10-150s) have helped in this way to discriminate between different landslide scenarios and to constrain rheological parameters (e.g. Favreau et al., 2010). This was possible as topography poorly affects wave propagation at these long periods and the landslide seismic source can be approximated as a point source. In the near-field and at higher frequencies (> 1 Hz) the spatial extent of the source has to be taken into account and the influence of the topography on the recorded seismic signal should be quantified in order to extract information on the landslide properties and dynamics. The characteristic signature of distributed sources and varying topographies is studied as a function of frequency and recording distance.The time dependent spatial distribution of the forces applied to the ground by the landslide are obtained using granular flow numerical modeling on 3D topography. The generated seismic waves are simulated using the spectral element method. The simulated seismic signal is compared to observed seismic data from rockfalls at the Dolomieu Crater of Piton de la Fournaise (La Réunion).Favreau, P., Mangeney, A., Lucas, A., Crosta, G., and Bouchut, F. (2010). Numerical modeling of landquakes. Geophysical Research Letters, 37(15):1-5.

  15. Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications

    Directory of Open Access Journals (Sweden)

    Williams Paul W.

    2010-07-01

    Full Text Available The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka. 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δ18O and δ13C values. The stable isotope time series were constructed using data from 15 speleothems from two different regions of the country. The greater the number of overlapping speleothem series (i.e. the greater the sample depth for any one region, the more confidence is justified in considering the stacked record to be representative of the region. Revising and extending earlier work, composite records are produced for central-west North Island (CWNI and north-west South Island (NWSI. Both demonstrate that over the last 15 ka the regions responded similarly to global climatic events, but that the North Island site was also influenced by the waxing and waning of regional subtropical marine influences that penetrated from the north but did not reach the higher latitudes of the South Island. Cooling marking the commencement of the last glacial maximum (LGM was evident from about 28 ka. There was a mid-LGM interstadial at 23-21.7 ka and Termination 1 occurred around 18.1 ka. The glacial-interglacial transition was marked by a series of negative excursions in δ18O that coincide with dated recessional moraines in South Island glaciers. A late glacial cooling event, the NZ Late Glacial Reversal, occurred from 13.4-11.2 ka and this was followed by an early Holocene optimum at 10.8 ka. Comparison of δ18O records from NWSI and EPICA DML ice-core shows climatic

  16. Frequency Distribution of Edentulous Posterior Mandibular Ridge Types using Cone Beam Computed Tomography in an Iranian Population

    Directory of Open Access Journals (Sweden)

    2016-07-01

    Full Text Available Introduction: The existing bone is regarded as an important criteria in dental implants. In this regard, the radiographic modality is of great significance in quantifying the remaining bone, and CBCT accurately represents height and width of the existing bone. Therefore, this study aimed to evaluate the frequency distribution of the edentulous posterior mandibular ridge types using cone beam computed tomography in an Iranian population. Methods: In this cross-sectional descriptive study, CBCT scans of 127 patients with full edentulous mandible with an average age of 61.15 were evaluated who referred to a radiology clinic in Tehran. The images were analyzed applying OnDemand3D application and bone height and width of each area were determined. To analyze the collected data, SPSS software (ver,17 was employed applying Fisher's exact test. Results: The ridges were classified in 4 different groups (A,B+,B-w,C-w. The frequency of ridge types A and B + in male and ridge types B-w and C-w in females were demonstrated to be higher. An increase in age led to a reduction in the frequency of type A and a rise in the frequency of type C-w. The mean bone height was higher in males in all areas. In addition, the mean bone width was higher in males in all areas except for the first molar area. Conclusions:  The study results indicated that as the age increases, the height of edentulous mandible reduces, while no significant relationship was detected between the bone width and aging. As a result, with aging the evolution of bone was held to be from type A to type C-W.

  17. Southern San Andreas Fault seismicity is consistent with the Gutenberg-Richter magnitude-frequency distribution

    Science.gov (United States)

    Page, Morgan T.; Felzer, Karen

    2015-01-01

    The magnitudes of any collection of earthquakes nucleating in a region are generally observed to follow the Gutenberg-Richter (G-R) distribution. On some major faults, however, paleoseismic rates are higher than a G-R extrapolation from the modern rate of small earthquakes would predict. This, along with other observations, led to formulation of the characteristic earthquake hypothesis, which holds that the rate of small to moderate earthquakes is permanently low on large faults relative to the large-earthquake rate (Wesnousky et al., 1983; Schwartz and Coppersmith, 1984). We examine the rate difference between recent small to moderate earthquakes on the southern San Andreas fault (SSAF) and the paleoseismic record, hypothesizing that the discrepancy can be explained as a rate change in time rather than a deviation from G-R statistics. We find that with reasonable assumptions, the rate changes necessary to bring the small and large earthquake rates into alignment agree with the size of rate changes seen in epidemic-type aftershock sequence (ETAS) modeling, where aftershock triggering of large earthquakes drives strong fluctuations in the seismicity rates for earthquakes of all magnitudes. The necessary rate changes are also comparable to rate changes observed for other faults worldwide. These results are consistent with paleoseismic observations of temporally clustered bursts of large earthquakes on the SSAF and the absence of M greater than or equal to 7 earthquakes on the SSAF since 1857.

  18. The Algebra of the Cumulative Percent Operation.

    Science.gov (United States)

    Berry, Andrew J.

    2002-01-01

    Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)

  19. Adaptive strategies for cumulative cultural learning.

    Science.gov (United States)

    Ehn, Micael; Laland, Kevin

    2012-05-21

    The demographic and ecological success of our species is frequently attributed to our capacity for cumulative culture. However, it is not yet known how humans combine social and asocial learning to generate effective strategies for learning in a cumulative cultural context. Here we explore how cumulative culture influences the relative merits of various pure and conditional learning strategies, including pure asocial and social learning, critical social learning, conditional social learning and individual refiner strategies. We replicate the Rogers' paradox in the cumulative setting. However, our analysis suggests that strategies that resolved Rogers' paradox in a non-cumulative setting may not necessarily evolve in a cumulative setting, thus different strategies will optimize cumulative and non-cumulative cultural learning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. How to define e-cigarette prevalence? Finding clues in the use frequency distribution.

    Science.gov (United States)

    Amato, Michael S; Boyle, Raymond G; Levy, David

    2016-04-01

    E-cigarette use has rapidly increased. Recent studies define prevalence using a variety of measures; competing definitions challenge cross-study comparison. We sought to understand patterns of use by investigating the number of days out of the past 30 days when adults had used e-cigarettes. We used the 2014 Minnesota Adult Tobacco Survey, a random digit dial population survey (n=9304 adults). Questions included ever using e-cigarettes, number of days used in the past 30 days and reasons for use. Smoking status was determined by combustible cigarette use. Histograms of e-cigarette use were visually inspected for current, former and never smokers with any 30-day e-cigarette use. Different definitions of current use were compared. Use ≤5 days in the past 30 days demarcated a cluster of infrequent users at the low end of the distribution. Among those with use in the past 30 days, infrequent users were the majorities of current (59%) and never smokers (89.5%), but fewer than half of former smokers (43.2%). Infrequent users were more likely to cite curiosity and less likely to cite quitting/cutting down other tobacco use as reasons for use. Defining adult prevalence as any use in the past 30 days may include experimenters unlikely to continue use, and is of questionable utility for population surveillance of public health trends over time. Defining prevalence as >5 days excludes those infrequent users. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. 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

  2. Modeling and distributed gain scheduling strategy for load frequency control in smart grids with communication topology changes.

    Science.gov (United States)

    Liu, Shichao; Liu, Xiaoping P; El Saddik, Abdulmotaleb

    2014-03-01

    In this paper, we investigate the modeling and distributed control problems for the load frequency control (LFC) in a smart grid. In contrast with existing works, we consider more practical and real scenarios, where the communication topology of the smart grid changes because of either link failures or packet losses. These topology changes are modeled as a time-varying communication topology matrix. By using this matrix, a new closed-loop power system model is proposed to integrate the communication topology changes into the dynamics of a physical power system. The globally asymptotical stability of this closed-loop power system is analyzed. A distributed gain scheduling LFC strategy is proposed to compensate for the potential degradation of dynamic performance (mean square errors of state vectors) of the power system under communication topology changes. In comparison to conventional centralized control approaches, the proposed method can improve the robustness of the smart grid to the variation of the communication network as well as to reduce computation load. Simulation results show that the proposed distributed gain scheduling approach is capable to improve the robustness of the smart grid to communication topology changes. © 2013 ISA. Published by ISA. All rights reserved.

  3. Plasma Temperature Determination of Hydrogen Containing High-Frequency Electrode less Lamps by Intensity Distribution Measurements of Hydrogen Molecular Band

    International Nuclear Information System (INIS)

    Gavare, Z.; Revalde, G.; Skudra, A.

    2011-01-01

    The goal of the present work was the investigation of the possibility to use intensity distribution of the Q-branch lines of the hydrogen Fulcher-a diagonal band (d3η u- a3Σg + electronic transition; Q-branch with ν=ν=2) to determine the temperature of hydrogen containing high-frequency electrode less lamps (HFEDLs). The values of the rotational temperatures have been obtained from the relative intensity distributions for hydrogen-helium and hydrogen-argon HFEDLs depending on the applied current. The results have been compared with the method of temperature derivation from Doppler profiles of He 667.8 nm and Ar 772.4 nm lines. The results of both methods are in good agreement, showing that the method of gas temperature determination from the intensity distribution in the hydrogen Fulcher-a (2-2)Q band can be used for the hydrogen containing HFEDLs. It was observed that the admixture of 10% hydrogen in the argon HFEDLs significantly reduces the gas temperature

  4. Use of Frequency Distribution Functions to Establish Safe Conditions in Relation to the Foodborne Pathogen Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Begoña Delgado

    2005-01-01

    Full Text Available Minimal processing implementation greatly depends on a detailed knowledge of the effects of preservation factors and their combinations on the spoilage and foodborne pathogenic microorganisms. The effectiveness of mild preservation conditions will become increasingly dependent on a more stochastic approach linking microbial physiological factors with product preservation factors. In this study, the validity of frequency distributions to efficiently describe the inactivation and growth of Bacillus cereus in the presence of natural antimicrobials (essential oils has been studied. For this purpose, vegetative cells were exposed to 0.6 mM of thymol or cymene, obtaining survival curves that were best described by the distribution of Weibull, since a tailing effect was observed. B. cereus was also exposed in a growth medium to a low concentration (0.1 mM of both antimicrobials, separately or combined, and the lag times obtained were fitted to a normal distribution, which allowed a description of dispersion of the start of growth. This allowed a more efficient evaluation of the experimental data to establish safe processing conditions according to accurate parameters and their implementation in risk assessment.

  5. 32 CFR 651.16 - Cumulative impacts.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Cumulative impacts. 651.16 Section 651.16... § 651.16 Cumulative impacts. (a) NEPA analyses must assess cumulative effects, which are the impact on the environment resulting from the incremental impact of the action when added to other past, present...

  6. A paradox of cumulative culture.

    Science.gov (United States)

    Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi

    2015-08-21

    Culture can grow cumulatively if socially learnt behaviors are improved by individual learning before being passed on to the next generation. Previous authors showed that this kind of learning strategy is unlikely to be evolutionarily stable in the presence of a trade-off between learning and reproduction. This is because culture is a public good that is freely exploited by any member of the population in their model (cultural social dilemma). In this paper, we investigate the effect of vertical transmission (transmission from parents to offspring), which decreases the publicness of culture, on the evolution of cumulative culture in both infinite and finite population models. In the infinite population model, we confirm that culture accumulates largely as long as transmission is purely vertical. It turns out, however, that introduction of even slight oblique transmission drastically reduces the equilibrium level of culture. Even more surprisingly, if the population size is finite, culture hardly accumulates even under purely vertical transmission. This occurs because stochastic extinction due to random genetic drift prevents a learning strategy from accumulating enough culture. Overall, our theoretical results suggest that introducing vertical transmission alone does not really help solve the cultural social dilemma problem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Active and reactive power sharing and frequency restoration in a distributed power system consisting of two UPS units

    Energy Technology Data Exchange (ETDEWEB)

    Parlak, Koray Sener; Oezdemir, Mehmet [Dept. of Electrical and Electronic Engineering, Firat University, Elazig, 23119 (Turkey); Aydemir, M. Timur [Dept. of Electrical and Electronic Engineering, Gazi University, Maltepe-Ankara 06570 (Turkey)

    2009-06-15

    A distributed power system consisting of two uninterrupted power supplies (UPS) is investigated in this paper. Parallel operation of the two sources increases the established power rating of the system. One of the sources can supply the system even when the other system is disconnected due to some faults, and this is an important feature. The control algorithm makes sure that the total load is shared between the supplies in accordance with their rated power levels, and the frequency of the supplies are restored to the rated values after the transitions. As the UPSs operate at an optimum power level, losses and faults due to overloading are prevented. The units safely operate without any means of communication between each other. The focus of the work is on the inverter stages of the UPSs. Simulations performed in Matlab Simulink environment have been verified with experimental work via DS1103 controller card. (author)

  8. Security analysis of orthogonal-frequency-division-multiplexing-based continuous-variable quantum key distribution with imperfect modulation

    Science.gov (United States)

    Zhang, Hang; Mao, Yu; Huang, Duan; Li, Jiawei; Zhang, Ling; Guo, Ying

    2018-05-01

    We introduce a reliable scheme for continuous-variable quantum key distribution (CV-QKD) by using orthogonal frequency division multiplexing (OFDM). As a spectrally efficient multiplexing technique, OFDM allows a large number of closely spaced orthogonal subcarrier signals used to carry data on several parallel data streams or channels. We place emphasis on modulator impairments which would inevitably arise in the OFDM system and analyze how these impairments affect the OFDM-based CV-QKD system. Moreover, we also evaluate the security in the asymptotic limit and the Pirandola-Laurenza-Ottaviani-Banchi upper bound. Results indicate that although the emergence of imperfect modulation would bring about a slight decrease in the secret key bit rate of each subcarrier, the multiplexing technique combined with CV-QKD results in a desirable improvement on the total secret key bit rate which can raise the numerical value about an order of magnitude.

  9. Semicircular canal dehiscence: Frequency and distribution on temporal bone CT and its relationship with the clinical outcomes

    International Nuclear Information System (INIS)

    Elmali, Muzaffer; Polat, Ahmet Veysel; Kucuk, Harun; Atmaca, Sinan; Aksoy, Ahmet

    2013-01-01

    Purpose: In this study, we aimed to investigate the frequency of SCD and its distribution and relationship with clinical outcomes on thin-section CT of the temporal bone. Materials and methods: Digital temporal bone CT images of 850 consecutive patients (1700 temporal bone CTs, 5100 SCs) who presented with a range of complaints such as vertigo, deafness, ear pain, fullness, and discharge between January 2008 and December 2011 were re-evaluated. Axial and oblique coronal reconstruction images of the temporal bone were made with a reconstruction thickness of 0.5 mm. Additionally, superior SC was evaluated in two perpendicular planes. Results: Out of 850 patients, 70 had completely normal temporal bone CT. Ninety-three patients had at least one SCD. In the temporal bone-based evaluation, 119 (26 bilateral, 67 unilateral) of 1700 temporal bones (7%) showed dehiscence. The SC-based evaluation revealed 125 SCD (2.5%) in 5100 SCs. The total number and rates of SCD were as follows: superior 103 (82.4%), posterior 13 (10.4%), and lateral nine (7.2%). Twenty of the 93 patients with SCD (21.5%) revealed no other findings on their temporal bone CTs. We determined a significant correlation between vestibular complaints, conductive hearing loss and SCD but there was no correlation between mixed, sensorineural hearing loss and SCD. Conclusion: We determined the frequency of SCD in 11% of patients and 7% of temporal bones. With regards to the distribution, the superior SC showed the highest dehiscence rate (82.4%). We found a significant correlation between vestibular symptoms, conductive hearing loss and SCD

  10. Semicircular canal dehiscence: Frequency and distribution on temporal bone CT and its relationship with the clinical outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Elmali, Muzaffer, E-mail: muzafel@yahoo.com.tr [Department of Radiology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Polat, Ahmet Veysel, E-mail: veyselp@hotmail.com [Department of Radiology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Kucuk, Harun, E-mail: hardrmd@yahoo.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Atmaca, Sinan, E-mail: sinanatmaca@yahoo.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Aksoy, Ahmet, E-mail: toxocara47@hotmail.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey)

    2013-10-01

    Purpose: In this study, we aimed to investigate the frequency of SCD and its distribution and relationship with clinical outcomes on thin-section CT of the temporal bone. Materials and methods: Digital temporal bone CT images of 850 consecutive patients (1700 temporal bone CTs, 5100 SCs) who presented with a range of complaints such as vertigo, deafness, ear pain, fullness, and discharge between January 2008 and December 2011 were re-evaluated. Axial and oblique coronal reconstruction images of the temporal bone were made with a reconstruction thickness of 0.5 mm. Additionally, superior SC was evaluated in two perpendicular planes. Results: Out of 850 patients, 70 had completely normal temporal bone CT. Ninety-three patients had at least one SCD. In the temporal bone-based evaluation, 119 (26 bilateral, 67 unilateral) of 1700 temporal bones (7%) showed dehiscence. The SC-based evaluation revealed 125 SCD (2.5%) in 5100 SCs. The total number and rates of SCD were as follows: superior 103 (82.4%), posterior 13 (10.4%), and lateral nine (7.2%). Twenty of the 93 patients with SCD (21.5%) revealed no other findings on their temporal bone CTs. We determined a significant correlation between vestibular complaints, conductive hearing loss and SCD but there was no correlation between mixed, sensorineural hearing loss and SCD. Conclusion: We determined the frequency of SCD in 11% of patients and 7% of temporal bones. With regards to the distribution, the superior SC showed the highest dehiscence rate (82.4%). We found a significant correlation between vestibular symptoms, conductive hearing loss and SCD.

  11. Predictions of ion energy distributions and radical fluxes in radio frequency biased inductively coupled plasma etching reactors

    Science.gov (United States)

    Hoekstra, Robert J.; Kushner, Mark J.

    1996-03-01

    Inductively coupled plasma (ICP) reactors are being developed for low gas pressure (radio frequency (rf) bias is applied to the substrate. One of the goals of these systems is to independently control the magnitude of the ion flux by the inductively coupled power deposition, and the acceleration of ions into the substrate by the rf bias. In high plasma density reactors the width of the sheath above the wafer may be sufficiently thin that ions are able to traverse it in approximately 1 rf cycle, even at 13.56 MHz. As a consequence, the ion energy distribution (IED) may have a shape typically associated with lower frequency operation in conventional reactive ion etching tools. In this paper, we present results from a computer model for the IED incident on the wafer in ICP etching reactors. We find that in the parameter space of interest, the shape of the IED depends both on the amplitude of the rf bias and on the ICP power. The former quantity determines the average energy of the IED. The latter quantity controls the width of the sheath, the transit time of ions across the sheath and hence the width of the IED. In general, high ICP powers (thinner sheaths) produce wider IEDs.

  12. Equivalent distributed capacitance model of oxide traps on frequency dispersion of C-V curve for MOS capacitors

    Science.gov (United States)

    Lu, Han-Han; Xu, Jing-Ping; Liu, Lu; Lai, Pui-To; Tang, Wing-Man

    2016-11-01

    An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi-Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. Project supported by the National Natural Science Foundation of China (Grant Nos. 61176100 and 61274112), the University Development Fund of the University of Hong Kong, China (Grant No. 00600009), and the Hong Kong Polytechnic University, China (Grant No. 1-ZVB1).

  13. Determination of plasma frequency, damping constant, and size distribution from the complex dielectric function of noble metal nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza Herrera, Luis J.; Arboleda, David Muñetón [Centro de Investigaciones Ópticas (CIOp), (CONICET La Plata-CIC) (Argentina); Schinca, Daniel C.; Scaffardi, Lucía B., E-mail: lucias@ciop.unlp.edu.ar [Centro de Investigaciones Ópticas (CIOp), (CONICET La Plata-CIC) (Argentina); Departamento de Ciencias Básicas, Facultad de Ingeniería, UNLP (Argentina)

    2014-12-21

    This paper develops a novel method for simultaneously determining the plasma frequency ω{sub P}   and the damping constant γ{sub free} in the bulk damped oscillator Drude model, based on experimentally measured real and imaginary parts of the metal refractive index in the IR wavelength range, lifting the usual approximation that restricts frequency values to the UV-deep UV region. Our method was applied to gold, silver, and copper, improving the relative uncertainties in the final values for ω{sub p} (0.5%–1.6%) and for γ{sub free} (3%–8%), which are smaller than those reported in the literature. These small uncertainties in ω{sub p} and γ{sub free} determination yield a much better fit of the experimental complex dielectric function. For the case of nanoparticles (Nps), a series expansion of the Drude expression (which includes ω{sub p} and γ{sub free} determined using our method) enables size-dependent dielectric function to be written as the sum of three terms: the experimental bulk dielectric function plus two size corrective terms, one for free electron, and the other for bound-electron contributions. Finally, size distribution of nanometric and subnanometric gold Nps in colloidal suspension was determined through fitting its experimental optical extinction spectrum using Mie theory based on the previously determined dielectric function. Results are compared with size histogram obtained from Transmission Electron Microscopy (TEM)

  14. Equivalent distributed capacitance model of oxide traps on frequency dispersion of C – V curve for MOS capacitors

    International Nuclear Information System (INIS)

    Lu Han-Han; Xu Jing-Ping; Liu Lu; Lai Pui-To; Tang Wing-Man

    2016-01-01

    An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C – V curve of MOS capacitors measured for a frequency range from 1 kHz to 1 MHz. The proposed model is based on the Fermi–Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal. The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data. Simulations indicate that the capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface, with negligible effects from the traps far from the interface, and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed. In addition, by excluding the negligible effect of oxide-trap conductance, the model avoids the use of imaginary numbers and complex calculations, and thus is simple and intuitive. (paper)

  15. Combined Deterministic and Stochastic Approach to Determine Spatial Distribution of Drought Frequency and Duration in the Great Hungarian Plain

    Science.gov (United States)

    Szabó, J. A.; Kuti, L.; Bakacsi, Zs.; Pásztor, L.; Tahy, Á.

    2009-04-01

    Drought is one of the major weather driven natural hazards, which has most harm impacts on environment, agricultural and hydrological factors than the other hazards. In spite of the fact that Hungary - that country is situated in Central Europe - belongs to the continental climate zone (influenced by Atlantic and Mediterranean streams) and this weather conditions should be favourable for agricultural production, the drought is a serious risk factor in Hungary, especially on the so called "Great Hungarian Plain", which area has been hit by severe drought events. These drought events encouraged the Ministry of Environment and Water of Hungary to embark on a countrywide drought planning programme to coordinate drought planning efforts throughout the country, to ensure that available water is used efficiently and to provide guidance on how drought planning can be accomplished. With regard to this plan, it is indispensable to analyze the regional drought frequency and duration in the target region of the programme as fundamental information for the further works. According to these aims, first we initiated a methodological development for simulating drought in a non-contributing area. As a result of this work, it has been agreed that the most appropriate model structure for our purposes using a spatially distributed physically based Soil-Vegetation-Atmosphere Transfer (SVAT) model embedded into a Markov Chain-Monte Carlo (MCMC) algorithm for estimate multi-year drought frequency and duration. In this framework: - the spatially distributed SVAT component simulates all the fundamental SVAT processes (such as: interception, snow-accumulation and melting, infiltration, water uptake by vegetation and evapotranspiration, vertical and horizontal distribution of soil moisture, etc.) taking the groundwater table as lower, and the hydrometeorological fields as upper boundary conditions into account; - and the MCMC based stochastic component generates time series of daily weather

  16. Analysis of LDPE-ZnO-clay nanocomposites using novel cumulative rheological parameters

    Science.gov (United States)

    Kracalik, Milan

    2017-05-01

    Polymer nanocomposites exhibit complex rheological behaviour due to physical and also possibly chemical interactions between individual phases. Up to now, rheology of dispersive polymer systems has been usually described by evaluation of viscosity curve (shear thinning phenomenon), storage modulus curve (formation of secondary plateau) or plotting information about dumping behaviour (e.g. Van Gurp-Palmen-plot, comparison of loss factor tan δ). On the contrary to evaluation of damping behaviour, values of cot δ were calculated and called as "storage factor", analogically to loss factor. Then values of storage factor were integrated over specific frequency range and called as "cumulative storage factor". In this contribution, LDPE-ZnO-clay nanocomposites with different dispersion grades (physical networks) have been prepared and characterized by both conventional as well as novel analysis approach. Next to cumulative storage factor, further cumulative rheological parameters like cumulative complex viscosity, cumulative complex modulus or cumulative storage modulus have been introduced.

  17. Frequency and spatial distribution of animal and object hoarder behavior in Curitiba, Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Graziela Ribeiro da Cunha

    Full Text Available Abstract: This study aimed to establish the frequency and spatial distribution of animal and object hoarding in Curitiba (Paraná State, the eighth most populous city in Brazil. All hoarding complaints received by the City Secretaries of Health, Environment and Social Assistance between September 2013 and April 2015 were collected (n = 226 and suspicious cases were individually investigated. A total of 113/226 (50% of complaints were confirmed as hoarding cases, representing an overall ratio of 6.45 cases per 100,000 inhabitants in Curitiba, of which 48/113 (42.5% involved object hoarders, 41/113 (36.3% animal hoarders and 24/113 (21.2% both animal and object hoarders. A correlation of total identified cases with neighborhood population density and all population stratums analyzed (total, gender, age was significantly positive (p < 0.01, and with neighborhood mean monthly income (r = -0.2; p = 0.03 significantly negative. A spatial cluster of cases was found in the north of the city (OR = 8.57; p < 0.01. Hoarding cases were relatively frequent in Curitiba and were associated with population distribution patterns and inversely related to neighborhood income.

  18. Effect of trophic level on the radiocesium frequency distribution in aquatic and terrestrial ecosystems at Chornobyl and nuclear sites in the United States

    International Nuclear Information System (INIS)

    Smith, Michael H.; Tsyusko-Omeltchenko, Olga; Oleksyk, Taras K.

    2003-01-01

    There are significant linear relationship between the standard deviation and the mean of radiocesium concentration for samples of soils, sediments, plants, and animals from Chornobyl and nuclear sites in the United States. The universal occurrence of this relationship in all types of samples suggests that a non-normal frequency distribution should be expected. The slopes of these relationships are similar for fish and mammals from the two regions of the world but those for plants are not. The slopes for plants are similar for aquatic and terrestrial ecosystems within each region. We hypothesize that there are relationships between the four moments of the frequency distribution of radiocesium (mean, variance, skewness, and kurtosis), and that these relationships are caused by the functional properties of the organisms and other characteristics of the ecosystem. The way in which radiocesium was distributed across the landscape does not seem to be a factor in determining the form of the frequency distribution. (author)

  19. Distribution of very low frequency earthquakes in the Nankai accretionary prism influenced by a subducting-ridge

    Science.gov (United States)

    Toh, Akiko; Obana, Koichiro; Araki, Eiichiro

    2018-01-01

    We investigated the distribution of very low frequency earthquakes (VLFEs) that occurred in the shallow accretionary prism of the eastern Nankai trough during one week of VLFE activity in October 2015. They were recorded very close from the sources by an array of broadband ocean bottom seismometers (BBOBSs) equipped in Dense Oceanfloor Network system for Earthquakes and Tsunamis 1 (DONET1). The locations of VLFEs estimated using a conventional envelope correlation method appeared to have a large scatter, likely due to effects of 3D structures near the seafloor and/or sources that the method could not handle properly. Therefore, we assessed their relative locations by introducing a hierarchal clustering analysis based on patterns of relative peak times of envelopes within the array measured for each VLFE. The results suggest that, in the northeastern side of the network, all the detected VLFEs occur 30-40 km landward of the trench axis, near the intersection of a splay fault with the seafloor. Some likely occurred along the splay fault. On the other hand, many VLFEs occur closer to the trench axis in the southwestern side, likely along the plate boundary, and the VLFE activity in the shallow splay fault appears less intense, compared to the northeastern side. Although this could be a snap-shot of activity that becomes more uniform over longer-term, the obtained distribution can be reasonably explained by the change in shear stresses and pore pressures caused by a subducting-ridge below the northeastern side of DONET1. The change in stress state along the strike of the plate boundary, inferred from the obtained VLFE distribution, should be an important indicator of the strain release pattern and localised variations in the tsunamigenic potential of this region.

  20. Ultra-stable long distance optical frequency distribution using the Internet fiber network and application to high-precision molecular spectroscopy

    International Nuclear Information System (INIS)

    Lopez, O; Chanteau, B; Bercy, A; Argence, B; Darquié, B; Chardonnet, C; Amy-Klein, A; Nicolodi, D; Zhang, W; Abgrall, M; Haboucha, A; Kanj, A; Rovera, D; Achkar, J; Pottie, P-E; Coq, Y Le; Santarelli, G

    2013-01-01

    We report an optical link of 540 km for ultrastable frequency distribution over the Internet fiber network. The phase-noise compensated link shows a fractional frequency instability in full bandwidth of 3×10 −14 at one second measurement time and 2×10 −18 at 30 000 s. This work is a significant step towards a sustainable wide area ultrastable optical frequency distribution and comparison network. Time transfer was demonstrated simultaneously on the same link and led to an absolute time accuracy (250 ps) and long-term timing stability (20 ps) which outperform the conventional satellite transfer methods by one order of magnitude. Current development addresses the question of multiple users distribution in the same metropolitan area. We demonstrate on-line extraction and first results show frequency stability at the same level as with conventional link. We also report an application to coherent frequency transfer to the mid-infrared. We demonstrate the frequency stabilisation of a mid-infrared laser to the near-infrared frequency reference transferred through the optical link. Fractional stability better than 4×10 −14 at 1 s averaging time was obtained, opening the way to ultrahigh resolution spectroscopy of molecular rovibrational transitions

  1. Proline: the distribution, frequency, positioning, and common functional roles of proline and polyproline sequences in the human proteome.

    Directory of Open Access Journals (Sweden)

    Alexander A Morgan

    Full Text Available Proline is an anomalous amino acid. Its nitrogen atom is covalently locked within a ring, thus it is the only proteinogenic amino acid with a constrained phi angle. Sequences of three consecutive prolines can fold into polyproline helices, structures that join alpha helices and beta pleats as architectural motifs in protein configuration. Triproline helices are participants in protein-protein signaling interactions. Longer spans of repeat prolines also occur, containing as many as 27 consecutive proline residues. Little is known about the frequency, positioning, and functional significance of these proline sequences. Therefore we have undertaken a systematic bioinformatics study of proline residues in proteins. We analyzed the distribution and frequency of 687,434 proline residues among 18,666 human proteins, identifying single residues, dimers, trimers, and longer repeats. Proline accounts for 6.3% of the 10,882,808 protein amino acids. Of all proline residues, 4.4% are in trimers or longer spans. We detected patterns that influence function based on proline location, spacing, and concentration. We propose a classification based on proline-rich, polyproline-rich, and proline-poor status. Whereas singlet proline residues are often found in proteins that display recurring architectural patterns, trimers or longer proline sequences tend be associated with the absence of repetitive structural motifs. Spans of 6 or more are associated with DNA/RNA processing, actin, and developmental processes. We also suggest a role for proline in Kruppel-type zinc finger protein control of DNA expression, and in the nucleation and translocation of actin by the formin complex.

  2. End plate marrow changes in the asymptomatic lumbosacral spine: frequency, distribution and correlation with age and degenerative changes

    International Nuclear Information System (INIS)

    Chung, Christine B.; Vande Berg, Bruno C.; Malghem, Jacques; Tavernier, Thierry; Cotten, Anne; Laredo, Jean-Denis; Vallee, Christian

    2004-01-01

    To investigate the frequency and distribution of end plate marrow signal intensity changes in an asymptomatic population and to correlate these findings with patient age and degenerative findings in the spine. MR imaging studies of the lumbosacral (LS) spine in 59 asymptomatic subjects were retrospectively reviewed by 2 musculoskeletal radiologists to determine the presence and location of fat-like and edema-like marrow signal changes about the end plates of the L1-2 through L5-S1 levels. The presence of degenerative changes in the spine was recorded as was patient age. Descriptive statistics were utilized to determine the frequency and associations of end plate findings and degenerative changes in the spine. Interobserver variability was determined by a kappa score. Binomial probability was used to predict the prevalence of the end plate changes in a similar subject population. The Fisher exact test was performed to determine statistical significance of the relationship of end plate changes with degenerative changes in the spine, superior versus inferior location about the disc and age of the patient population. Focal fat-like signal intensity adjacent to the vertebral end-plate was noted in 15 out of 59 subjects by both readers, and involved 38 and 36 out of 590 end plates by readers 1 and 2, respectively. Focal edema-like signal intensity adjacent to the vertebral end plate was noted in 8 out of 59 subjects by both readers and involved 11 and 10 out of 590 end plates by readers 1 and 2, respectively. Either fat or edema signal intensity occurred most often at the anterior (p<.05) aspects of the mid-lumbar spine and was seen in an older sub-population of the study (p<.05). End plate marrow signal intensity changes are present in the lumbar spine of some asymptomatic subjects with a characteristic location along the spine and in vertebral end plates. (orig.)

  3. Regolith thickness over Sinus Iridum: Results from morphology and size-frequency distribution of small impact craters

    Science.gov (United States)

    Fa, Wenzhe; Liu, Tiantian; Zhu, Meng-Hua; Haruyama, Junichi

    2014-08-01

    High-resolution optical images returned from recent lunar missions provide a new chance for estimation of lunar regolith thickness using morphology and the size-frequency distribution of small impact craters. In this study, regolith thickness over the Sinus Iridum region is estimated using Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Cameras (NACs) images. A revised relationship between crater geometry and regolith thickness is proposed based on old experimental data that takes into considering the effect of the illumination angle of the images. In total, 227 high-resolution LROC NAC images are used, and 378,556 impact craters with diameters from 4.2 to 249.8 m are counted, and their morphologies are identified. Our results show that 50% of the Sinus Iridum region has a regolith thickness between 5.1 and 10.7 m, and the mean and median regolith thicknesses are 8.5 and 8.0 m, respectively. There are substantial regional variations in the regolith thickness, with its median value varying from 2.6 to 12.0 m for most regions. Local variations of regolith thickness are found to be correlated with the lunar surface age: the older the surface, the greater the thickness. In addition, sporadically distributed impact ejecta and crater rays are associated with relatively larger regolith thickness, which might result from excavation and transport of materials during the formation of the secondaries of Copernican-aged craters. Our estimated regolith thickness can help with future analysis of Chang'E-3 lunar penetrating radar echoes and studies of the subsurface stratigraphic structure of the Moon.

  4. Evidence for Sexual Reproduction: Identification, Frequency, and Spatial Distribution of Venturia effusa (Pecan Scab) Mating Type Idiomorphs.

    Science.gov (United States)

    Young, Carolyn A; Bock, Clive H; Charlton, Nikki D; Mattupalli, Chakradhar; Krom, Nick; Bowen, Joanna K; Templeton, Matthew; Plummer, Kim M; Wood, Bruce W

    2018-05-10

    Venturia effusa (syn. Fusicladium effusum), causal agent of pecan scab, is the most prevalent pathogen of pecan (Carya illinoinensis), causing severe yield losses in the southeastern United States. V. effusa is currently known only by its asexual (conidial) stage. However, the degree and distribution of genetic diversity observed within and among populations of V. effusa are typical of a sexually reproducing fungal pathogen, and comparable with other dothideomycetes with a known sexual stage, including the closely related apple scab pathogen, V. inaequalis. Using the mating type (MAT) idiomorphs from V. inaequalis, we identified a single MAT gene, MAT1-1-1, in a draft genome of V. effusa. The MAT1-1-1 locus is flanked by two conserved genes encoding a DNA lyase (APN2) and a hypothetical protein. The MAT locus spanning the flanking genes was amplified and sequenced from a subset of 14 isolates, of which 7 contained MAT1-1-1 and the remaining samples contained MAT1-2-1. A multiplex polymerase chain reaction screen was developed to amplify MAT1-1-1, MAT1-2-1, and a conserved reference gene encoding β-tubulin, and used to screen 784 monoconidial isolates of V. effusa collected from 11 populations of pecan across the southeastern United States. A hierarchical sampling protocol representing region, orchard, and tree allowed for analysis of MAT structure at different spatial scales. Analysis of this collection revealed the frequency of the MAT idiomorphs is in a 1:1 equilibrium of MAT1-1:MAT1-2. The apparent equilibrium of the MAT idiomorphs provides impetus for a renewed effort to search for the sexual stage of V. effusa. [Formula: see text] Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

  5. Cumulative trauma disorders: A review.

    Science.gov (United States)

    Iqbal, Zaheen A; Alghadir, Ahmad H

    2017-08-03

    Cumulative trauma disorder (CTD) is a term for various injuries of the musculoskeletal and nervous systems that are caused by repetitive tasks, forceful exertions, vibrations, mechanical compression or sustained postures. Although there are many studies citing incidence of CTDs, there are fewer articles about its etiology, pathology and management. The aim of our study was to discuss the etiology, pathogenesis, prevention and management of CTDs. A literature search was performed using various electronic databases. The search was limited to articles in English language pertaining to randomized clinical trials, cohort studies and systematic reviews of CTDs. A total of 180 papers were identified to be relevant published since 1959. Out of these, 125 papers reported about its incidence and 50 about its conservative treatment. Workplace environment, same task repeatability and little variability, decreased time for rest, increase in expectations are major factors for developing CTDs. Prevention of its etiology and early diagnosis can be the best to decrease its incidence and severity. For effective management of CTDs, its treatment should be divided into Primordial, Primary, Secondary and Tertiary prevention.

  6. Complete cumulative index (1963-1983)

    International Nuclear Information System (INIS)

    1983-01-01

    This complete cumulative index covers all regular and special issues and supplements published by Atomic Energy Review (AER) during its lifetime (1963-1983). The complete cumulative index consists of six Indexes: the Index of Abstracts, the Subject Index, the Title Index, the Author Index, the Country Index and the Table of Elements Index. The complete cumulative index supersedes the Cumulative Indexes for Volumes 1-7: 1963-1969 (1970), and for Volumes 1-10: 1963-1972 (1972); this Index also finalizes Atomic Energy Review, the publication of which has recently been terminated by the IAEA

  7. Variation in size frequency distribution of coral populations under different fishing pressures in two contrasting locations in the Indian Ocean.

    Science.gov (United States)

    Grimsditch, G; Pisapia, C; Huck, M; Karisa, J; Obura, D; Sweet, M

    2017-10-01

    This study aimed to assess how the size-frequency distributions of coral genera varied between reefs under different fishing pressures in two contrasting Indian Ocean locations (the Maldives and East Africa). Using generalized linear mixed models, we were able to demonstrate that complex interactions occurred between coral genera, coral size class and fishing pressure. In both locations, we found Acropora coral species to be more abundant in non-fished compared to fished sites (a pattern which was consistent for nearly all the assessed size classes). Coral genera classified as 'stress tolerant' showed a contrasting pattern i.e. were higher in abundance in fished compared to non-fished sites. Site specific variations were also observed. For example, Maldivian reefs exhibited a significantly higher abundance in all size classes of 'competitive' corals compared to East Africa. This possibly indicates that East African reefs have already been subjected to higher levels of stress and are therefore less suitable environments for 'competitive' corals. This study also highlights the potential structure and composition of reefs under future degradation scenarios, for example with a loss of Acropora corals and an increase in dominance of 'stress tolerant' and 'generalist' coral genera. Copyright © 2017. Published by Elsevier Ltd.

  8. Analysis of Maneuvering Targets with Complex Motions by Two-Dimensional Product Modified Lv's Distribution for Quadratic Frequency Modulation Signals.

    Science.gov (United States)

    Jing, Fulong; Jiao, Shuhong; Hou, Changbo; Si, Weijian; Wang, Yu

    2017-06-21

    For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM) signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR) and the quadratic chirp rate (QCR) are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF) and modified scaled Fourier transform (mSFT), an effective parameter estimation algorithm is proposed-referred to as the Two-Dimensional product modified Lv's distribution (2D-PMLVD)-for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT) and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.

  9. Spatial variations in the frequency-magnitude distribution of earthquakes at Soufriere Hills Volcano, Montserrat, West Indies

    Science.gov (United States)

    Power, J.A.; Wyss, M.; Latchman, J.L.

    1998-01-01

    The frequency-magnitude distribution of earthquakes measured by the b-value is determined as a function of space beneath Soufriere Hills Volcano, Montserrat, from data recorded between August 1, 1995 and March 31, 1996. A volume of anomalously high b-values (b > 3.0) with a 1.5 km radius is imaged at depths of 0 and 1.5 km beneath English's Crater and Chance's Peak. This high b-value anomaly extends southwest to Gage's Soufriere. At depths greater than 2.5 km volumes of comparatively low b-values (b-1) are found beneath St. George's Hill, Windy Hill, and below 2.5 km depth and to the south of English's Crater. We speculate the depth of high b-value anomalies under volcanoes may be a function of silica content, modified by some additional factors, with the most siliceous having these volumes that are highly fractured or contain high pore pressure at the shallowest depths. Copyright 1998 by the American Geophysical Union.

  10. The distribution and frequency of blood lipid testing by sociodemographic status among adults in Auckland, New Zealand.

    Science.gov (United States)

    Exeter, Daniel J; Moss, Lauren; Zhao, Jinfeng; Kyle, Cam; Riddell, Tania; Jackson, Rod; Wells, Susan

    2015-09-01

    National cardiovascular disease (CVD) guidelines recommend that adults have cholesterol levels monitored regularly. However, little is known about the extent and equity of cholesterol testing in New Zealand. To investigate the distribution and frequency of blood lipid testing by sociodemographic status in Auckland, New Zealand. We anonymously linked five national health datasets (primary care enrolment, laboratory tests, pharmaceuticals, hospitalisations and mortality) to identify adults aged ≥25 years without CVD or diabetes who had their lipids tested in 2006-2010, by age, gender, ethnicity and area of residence and deprivation. Multivariate logistic regression was used to estimate the likelihood of testing associated with these factors. Of the 627 907 eligible adults, 66.3% had at least one test between 2006 and 2010. Annual testing increased from 24.7% in 2006 to 35.1% in 2010. Testing increased with age similarly for men and women. Indian people were 87% more likely than New Zealand European and Others (NZEO) to be tested, Pacific people 8% more likely, but rates for Maori were similar to NZEO. There was marked variation within the region, with residents of the most deprived areas less likely to be tested than residents in least deprived areas. Understanding differences within and between population groups supports the development of targeted strategies for better service utilisation. While lipid testing has increased, sociodemographic variations persist by place of residence, and deprivation. Of the high CVD risk populations, lipid testing for Maori and Pacific is not being conducted according to need.

  11. Exploratory analysis of dynamics of frequency distribution of raw cow milk quality indicators in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Oto Hanuš

    2011-01-01

    Full Text Available A consistent link of the raw milk quality (RMQ to the farmer price is essential. The aim was to analyse the properties of milk quality indicators (MQIs and propose a new synthetic relative MQI (SQSM from among various individual MQIs. SQSM could serve for consistent inclusion each quality change into the price. The paper was focused on exploratory analysis (normality (N testing of files of MQIs. On the basis of the results, the MQIs were divided into two groups without and with necessity of original data transformation (TRN. Log and Box–Cox TRNs were tested in terms of possibilities of the files approach to the normal data frequency distribution (FD. The compositional MQIs deviated less and health and hygienic MQIs more from normal FD in original data (P < 0.05. The TRNs approached the data files to N very markedly in health and hygienic MQIs. The synthesis of various values of MQIs into SQSM was proposed. SQSM values were derived from model file of real data about MQIs and validated for use at farmer milk price modifications by the normality FD test. 33.3% of month SQSM files were normal (P > 0.05, the other were very close to the N with negligible deviations. The useability of the SQSM system for the balancing of raw milk purchase price premiums and penalties was tentatively confirmed.

  12. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...

  13. Cumulative Student Loan Debt in Minnesota, 2015

    Science.gov (United States)

    Williams-Wyche, Shaun

    2016-01-01

    To better understand student debt in Minnesota, the Minnesota Office of Higher Education (the Office) gathers information on cumulative student loan debt from Minnesota degree-granting institutions. These data detail the number of students with loans by institution, the cumulative student loan debt incurred at that institution, and the percentage…

  14. Smart microgrid hierarchical frequency control ancillary service provision based on virtual inertia concept: An integrated demand response and droop controlled distributed generation framework

    International Nuclear Information System (INIS)

    Rezaei, Navid; Kalantar, Mohsen

    2015-01-01

    Highlights: • Detailed formulation of the microgrid static and dynamic securities based on droop control and virtual inertia concepts. • Constructing a novel objective function using frequency excursion and rate of change of frequency profiles. • Ensuring the microgrid security subject to the microgrid economic and environmental policies. • Coordinated management of demand response and droop controlled distributed generation resources. • Precise scheduling of day-ahead hierarchical frequency control ancillary services using a scenario based stochastic programming. - Abstract: Low inertia stack, high penetration levels of renewable energy source and great ratio of power deviations in a small power delivery system put microgrid frequency at risk of instability. On the basis of the close coupling between the microgrid frequency and system security requirements, procurement of adequate ancillary services from cost-effective and environmental friendly resources is a great challenge requests an efficient energy management system. Motivated by this need, this paper presents a novel energy management system that is aimed to coordinately manage the demand response and distributed generation resources. The proposed approach is carried out by constructing a hierarchical frequency control structure in which the frequency dependent control functions of the microgrid components are modeled comprehensively. On the basis of the derived modeling, both the static and dynamic frequency securities of an islanded microgrid are provided in primary and secondary control levels. Besides, to cope with the low inertia stack of islanded microgrids, novel virtual inertia concept is devised based on the precise modeling of droop controlled distributed generation resources. The proposed approach is applied to typical test microgrid. Energy and hierarchical reserve resource are scheduled precisely using a scenario-based stochastic programming methodology. Moreover, analyzing the

  15. Cumulative prospect theory and mean variance analysis. A rigorous comparison

    OpenAIRE

    Hens, Thorsten; Mayer, Janos

    2012-01-01

    We compare asset allocations derived for cumulative prospect theory(CPT) based on two different methods: Maximizing CPT along the mean–variance efficient frontier and maximizing it without that restriction. We find that with normally distributed returns the difference is negligible. However, using standard asset allocation data of pension funds the difference is considerable. Moreover, with derivatives like call options the restriction to the mean-variance efficient frontier results in a siza...

  16. Plio-Pleistocene extinctions and immigration credit reflected in the size-frequency distribution of Mediterranean marine bivalves

    Science.gov (United States)

    Nawrot, Rafal; Zuschin, Martin; Chattopadhyay, Devapriya

    2015-04-01

    Following the opening of the Suez Canal hundreds of Red Sea species have entered the Mediterranean Sea making it a global hot spot of marine bioinvasion. With the ongoing influx of the subtropical and tropical alien species and increasing sea surface temperatures, the Mediterranean biota is currently gaining a more tropical character and increasingly becoming a mixture of faunal stocks with different evolutionary histories. This susceptibility to invasion was suggested to reflect the presence of an empty ecological space left after decimation of incumbent warm-water fauna during Plio-Pleistocene climate fluctuations. As molluscs are among the most prolific immigrants, we test this hypothesis using data on taxonomic composition and body size of Pliocene Mediterranean bivalves derived from the literature sources and museum collections. The Pliocene inter-specific size-frequency distribution (SFD) is strikingly similar to the SFDs of the Recent Red Sea bivalve fauna, in spite of different biogeographic provenance and the absence of true reef ecosystems in the Pliocene of the Mediterranean region. In contrast, body-size patterns in both assemblages are significantly different from the present-day Mediterranean fauna characterized by smaller median and modal size. Our preliminary results suggest that the distinct shape of the modern Mediterranean SFD may reflect the selective nature of the late Piacenzian - Galesian (Late Pliocene - Early Pleistocene) extinctions pulses related to the onset of the Northern Hemisphere glaciations. These extinctions affected almost 40% of Pliocene species and were biased towards large-bodied taxa. They were not followed by re-immigration of warm-water species owing to the isolation from the tropical Atlantic biota by the cold upwelling along the NW coasts of Africa. The resulting invasion credit (sensu Jackson & Sax, 2010) is currently being paid by the Red Sea bivalves colonizing the Mediterranean Sea through the Suez Canal. Successful

  17. Frequency Distribution of Hearing Disorders Among the Student of Public Elementary school in EslamAbad Gharb

    Directory of Open Access Journals (Sweden)

    Dr. Abdollah Mousavi

    2000-05-01

    Full Text Available Objects Determining the frequency distribution of hearing disorders among the student of public elementary school by Otoscopy, Puretone Audiometry, impedance Audiometry and questionnaires. Methods and Materials: This study was can-led out in a cross - sectional descriptive survey - on 1000 students (500 girls and 500 boys among the student of primary school of EslamAhad Gharh, academic year 1376-77 Results: 1- Otoscopy examination; abnormal conditions of external ear canal was found in 13.65% of cases; mostly impacted ceruman (13.3%. Abnormal conditions of external ear canal was more prevalent in girls than boys and the difference was statistically meaningful in the right (P V=0 .012 and left (PV=0.043 ear. Abnormal tympanic membrane was seen in 6.75% of cases; mostly retraction (295%. "n2- Impedance Audiometry: 11.05% abnormal tympanograms were observed, mostly type C (4.1%. 3- Pure Tone Audiometry: An overall 9.7% hearing loss was found in this population including 3.5% bilateral and 6.2% unilateral hearing loss. 4.15% of population suffered from SNHL observed mostly in boys and conductive. Hearing loss mostly in girls and the difference was statistically meaning in the left ear (PV=0.03. (l.e 0.6% were in need of rehabilitation services. Family background showed on effects on the hearing disorders. Only 11. 4% of parents, 13.4% of teachers and 14.4% of afflicted students were aware of the problem.

  18. Structure-borne low-frequency noise from multi-span bridges: A prediction method and spatial distribution

    Science.gov (United States)

    Song, X. D.; Wu, D. J.; Li, Q.; Botteldooren, D.

    2016-04-01

    Structure-borne noise from railway bridges at far-field points is an important indicator in environmental noise assessment. However, studies that predict structure-borne noise tend to model only single-span bridges, thus ignoring the sound pressure radiating from adjacent spans. To simulate the noise radiating from multi-span bridges induced by moving vehicles, the vibrations of a multi-span bridge are first obtained from a three-dimensional (3D) vehicle-track-bridge dynamic interaction simulation using the mode superposition method. A procedure based on the 2.5-dimensional (2.5D) boundary element method (BEM) is then presented to promote the efficiency of acoustical computation compared with the 3D BEM. The simulated results obtained from both the single-span and multi-span bridge models are compared with the measured results. The sound predictions calculated from the single-span model are accurate only for a minority of near-field points. In contrast, the sound pressures calculated from the multi-span bridge model match the measured results in both the time and frequency domains for all of the near-field and far-field points. The number of bridge spans required in the noise simulation is then recommended related to the distance between the track center and the field points of interest. The spatial distribution of multi-span structure-borne noise is also studied. The variation in sound pressure levels is insignificant along the length of the bridge, which validates the finding that the sound test section can be selected at an arbitrary plane perpendicular to the multi-span bridge.

  19. Time–frequency analysis of nonstationary complex magneto-hydro-dynamics in fusion plasma signals using the Choi–Williams distribution

    International Nuclear Information System (INIS)

    Xu, L.Q.; Hu, L.Q.; Chen, K.Y.; Li, E.Z.

    2013-01-01

    Highlights: • Choi–Williams distribution yields excellent time–frequency resolution for discrete signal. • CWD method provides clear time–frequency pictures of EAST and HT-7 fast MHD events. • CWD method has advantages to wavelets transform scalogram and the short-time Fourier transform spectrogram. • We discuss about how to choose the windows and free parameter of CWD method. -- Abstract: The Choi–Williams distribution is applied to the time–frequency analysis of signals describing rapid magneto-hydro-dynamic (MHD) modes and events in tokamak plasmas. A comparison is made with Soft X-ray (SXR) signals as well as Mirnov signal that shows the advantages of the Choi–Williams distribution over both continuous wavelets transform scalogram and the short-time Fourier transform spectrogram. Examples of MHD activities in HT-7 and EAST tokamak are shown, namely the onset of coupling tearing modes, high frequency precursors of sawtooth, and low frequency MHD instabilities in edge localized mode (ELM) free in H mode discharge

  20. Application of a frequency distribution method for determining instars of the beet armyworm (Lepidoptera: Noctuidae) from widths of cast head capsules

    Science.gov (United States)

    Y. Chen; S. J. Seybold

    2013-01-01

    Instar determination of field-collected insect larvae has generally been based on the analysis of head capsule width frequency distributions or bivariate plotting, but few studies have tested the validity of such methods. We used head capsules from exuviae of known instars of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae),...

  1. Simulation of beam-splitter made of metamaterials with angle spatial distribution of constitutive parameters based on transformation optics for THz frequency range

    International Nuclear Information System (INIS)

    Gurvitz, E A; Vozianova, A V; Khodzitsky, M K

    2014-01-01

    New approach to design beam splitter on basis of the transformation optics using angle constitutive parameters distribution of medium was proposed. The beam splitter was numerically simulated by COMSOL Multiphysics for terahertz frequency range. The numerical simulations were carried out for ideal and reduced constitutive parameters of medium for the case of TM plane wave

  2. A distributed model predictive control based load frequency control scheme for multi-area interconnected power system using discrete-time Laguerre functions.

    Science.gov (United States)

    Zheng, Yang; Zhou, Jianzhong; Xu, Yanhe; Zhang, Yuncheng; Qian, Zhongdong

    2017-05-01

    This paper proposes a distributed model predictive control based load frequency control (MPC-LFC) scheme to improve control performances in the frequency regulation of power system. In order to reduce the computational burden in the rolling optimization with a sufficiently large prediction horizon, the orthonormal Laguerre functions are utilized to approximate the predicted control trajectory. The closed-loop stability of the proposed MPC scheme is achieved by adding a terminal equality constraint to the online quadratic optimization and taking the cost function as the Lyapunov function. Furthermore, the treatments of some typical constraints in load frequency control have been studied based on the specific Laguerre-based formulations. Simulations have been conducted in two different interconnected power systems to validate the effectiveness of the proposed distributed MPC-LFC as well as its superiority over the comparative methods. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Quantitative cumulative biodistribution of antibodies in mice

    Science.gov (United States)

    Yip, Victor; Palma, Enzo; Tesar, Devin B; Mundo, Eduardo E; Bumbaca, Daniela; Torres, Elizabeth K; Reyes, Noe A; Shen, Ben Q; Fielder, Paul J; Prabhu, Saileta; Khawli, Leslie A; Boswell, C Andrew

    2014-01-01

    The neonatal Fc receptor (FcRn) plays an important and well-known role in antibody recycling in endothelial and hematopoietic cells and thus it influences the systemic pharmacokinetics (PK) of immunoglobulin G (IgG). However, considerably less is known about FcRn’s role in the metabolism of IgG within individual tissues after intravenous administration. To elucidate the organ distribution and gain insight into the metabolism of humanized IgG1 antibodies with different binding affinities FcRn, comparative biodistribution studies in normal CD-1 mice were conducted. Here, we generated variants of herpes simplex virus glycoprotein D-specific antibody (humanized anti-gD) with increased and decreased FcRn binding affinity by genetic engineering without affecting antigen specificity. These antibodies were expressed in Chinese hamster ovary cell lines, purified and paired radiolabeled with iodine-125 and indium-111. Equal amounts of I-125-labeled and In-111-labeled antibodies were mixed and intravenously administered into mice at 5 mg/kg. This approach allowed us to measure both the real-time IgG uptake (I-125) and cumulative uptake of IgG and catabolites (In-111) in individual tissues up to 1 week post-injection. The PK and distribution of the wild-type IgG and the variant with enhanced binding for FcRn were largely similar to each other, but vastly different for the rapidly cleared low-FcRn-binding variant. Uptake in individual tissues varied across time, FcRn binding affinity, and radiolabeling method. The liver and spleen emerged as the most concentrated sites of IgG catabolism in the absence of FcRn protection. These data provide an increased understanding of FcRn’s role in antibody PK and catabolism at the tissue level. PMID:24572100

  4. Energy storage systems impact on the short-term frequency stability of distributed autonomous microgrids, an analysis using aggregate models

    DEFF Research Database (Denmark)

    Serban, Ioan; Teodorescu, Remus; Marinescu, Corneliu

    2013-01-01

    This study analyses the integration impact of battery energy storage systems (BESSs) on the short-term frequency control in autonomous microgrids (MGs). Short-term frequency stability relates with the primary or speed control level, as defined in the regulations of the classical grids. The focus...

  5. Origin of discrepancies between crater size-frequency distributions of coeval lunar geologic units via target property contrasts

    Science.gov (United States)

    van der Bogert, C. H.; Hiesinger, H.; Dundas, C. M.; Krüger, T.; McEwen, A. S.; Zanetti, M.; Robinson, M. S.

    2017-12-01

    Recent work on dating Copernican-aged craters, using Lunar Reconnaissance Orbiter (LRO) Camera data, re-encountered a curious discrepancy in crater size-frequency distribution (CSFD) measurements that was observed, but not understood, during the Apollo era. For example, at Tycho, Copernicus, and Aristarchus craters, CSFDs of impact melt deposits give significantly younger relative and absolute model ages (AMAs) than impact ejecta blankets, although these two units formed during one impact event, and would ideally yield coeval ages at the resolution of the CSFD technique. We investigated the effects of contrasting target properties on CSFDs and their resultant relative and absolute model ages for coeval lunar impact melt and ejecta units. We counted craters with diameters through the transition from strength- to gravity-scaling on two large impact melt deposits at Tycho and King craters, and we used pi-group scaling calculations to model the effects of differing target properties on final crater diameters for five different theoretical lunar targets. The new CSFD for the large King Crater melt pond bridges the gap between the discrepant CSFDs within a single geologic unit. Thus, the observed trends in the impact melt CSFDs support the occurrence of target property effects, rather than self-secondary and/or field secondary contamination. The CSFDs generated from the pi-group scaling calculations show that targets with higher density and effective strength yield smaller crater diameters than weaker targets, such that the relative ages of the former are lower relative to the latter. Consequently, coeval impact melt and ejecta units will have discrepant apparent ages. Target property differences also affect the resulting slope of the CSFD, with stronger targets exhibiting shallower slopes, so that the final crater diameters may differ more greatly at smaller diameters. Besides their application to age dating, the CSFDs may provide additional information about the

  6. On the relation between activity-related frequency shifts and the sunspot distribution over the solar cycle 23

    Directory of Open Access Journals (Sweden)

    Santos Ângela R. G.

    2017-01-01

    Full Text Available The activity-related variations in the solar acoustic frequencies have been known for 30 years. However, the importance of the different contributions is still not well established. With this in mind, we developed an empirical model to estimate the spot-induced frequency shifts, which takes into account the sunspot properties, such as area and latitude. The comparison between the model frequency shifts obtained from the daily sunspot records and those observed suggests that the contribution from a stochastic component to the total frequency shifts is about 30%. The remaining 70% is related to a global, long-term variation. We also propose a new observable to investigate the short-and mid-term variations of the frequency shifts, which is insensitive to the long-term variations contained in the data. On the shortest time scales the variations in the frequency shifts are strongly correlated with the variations in the total area covered by sunspots. However, a significant loss of correlation is still found, which cannot be fully explained by ignoring the invisible side of the Sun when accounting for the total sunspot area. We also verify that the times when the frequency shifts and the sunspot areas do not vary in a similar way tend to coincide with the times of the maximum amplitude of the quasi-biennial variations found in the seismic data.

  7. Ion energy distributions in a pulsed dual frequency inductively coupled discharge of Ar/CF4 and effect of duty ratio

    International Nuclear Information System (INIS)

    Mishra, Anurag; Seo, Jin Seok; Kim, Tae Hyung; Yeom, Geun Young

    2015-01-01

    Controlling time averaged ion energy distribution (IED) is becoming increasingly important in many plasma material processing applications for plasma etching and deposition. The present study reports the evolution of ion energy distributions with radio frequency (RF) powers in a pulsed dual frequency inductively discharge and also investigates the effect of duty ratio. The discharge has been sustained using two radio frequency, low (P 2 MHz  = 2 MHz) and high (P 13.56 MHz  = 13.56 MHz) at a pressure of 10 mTorr in argon (90%) and CF 4 (10%) environment. The low frequency RF powers have been varied from 100 to 600 W, whereas the high frequency powers from 200 to 1200 W. Typically, IEDs show bimodal structure and energy width (energy separation between the high and low energy peaks) increases with increasing P 13.56 MHz ; however, it shows opposite trends with P 2 MHz . It has been observed that IEDs bimodal structure tends to mono-modal structure and energy peaks shift towards low energy side as duty ratio increases, keeping pulse power owing to mode transition (capacitive to inductive) constant

  8. The Relationship between Gender, Cumulative Adversities and ...

    African Journals Online (AJOL)

    The Relationship between Gender, Cumulative Adversities and Mental Health of Employees in ... CAs were measured in three forms (family adversities (CAFam), personal adversities ... Age of employees ranged between 18-65 years.

  9. Cumulative cultural learning: Development and diversity

    Science.gov (United States)

    2017-01-01

    The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children’s learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission—the cornerstone of human cultural diversity. PMID:28739945

  10. Complexity and demographic explanations of cumulative culture

    NARCIS (Netherlands)

    Querbes, A.; Vaesen, K.; Houkes, W.N.

    2014-01-01

    Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological

  11. Cumulative cultural learning: Development and diversity.

    Science.gov (United States)

    Legare, Cristine H

    2017-07-24

    The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children's learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission-the cornerstone of human cultural diversity.

  12. About the cumulants of periodic signals

    Science.gov (United States)

    Barrau, Axel; El Badaoui, Mohammed

    2018-01-01

    This note studies cumulants of time series. These functions originating from the probability theory being commonly used as features of deterministic signals, their classical properties are examined in this modified framework. We show additivity of cumulants, ensured in the case of independent random variables, requires here a different hypothesis. Practical applications are proposed, in particular an analysis of the failure of the JADE algorithm to separate some specific periodic signals.

  13. Cumulative effects assessment: Does scale matter?

    International Nuclear Information System (INIS)

    Therivel, Riki; Ross, Bill

    2007-01-01

    Cumulative effects assessment (CEA) is (or should be) an integral part of environmental assessment at both the project and the more strategic level. CEA helps to link the different scales of environmental assessment in that it focuses on how a given receptor is affected by the totality of plans, projects and activities, rather than on the effects of a particular plan or project. This article reviews how CEAs consider, and could consider, scale issues: spatial extent, level of detail, and temporal issues. It is based on an analysis of Canadian project-level CEAs and UK strategic-level CEAs. Based on a review of literature and, especially, case studies with which the authors are familiar, it concludes that scale issues are poorly considered at both levels, with particular problems being unclear or non-existing cumulative effects scoping methodologies; poor consideration of past or likely future human activities beyond the plan or project in question; attempts to apportion 'blame' for cumulative effects; and, at the plan level, limited management of cumulative effects caused particularly by the absence of consent regimes. Scale issues are important in most of these problems. However both strategic-level and project-level CEA have much potential for managing cumulative effects through better siting and phasing of development, demand reduction and other behavioural changes, and particularly through setting development consent rules for projects. The lack of strategic resource-based thresholds constrains the robust management of strategic-level cumulative effects

  14. Experiences with non-intrusive monitoring of distribution transformers based on the on-line frequency response

    OpenAIRE

    Eduardo Gomez Luna

    2015-01-01

    The following article presents the results obtained in experiences that use the Impulse Frequency Response Analysis (IFRA) method with a transformer in service. The IFRA method has been implemented in order to transform the transient signals to the frequency domain using Discrete Fourier Transform (DFT). However, it can be considered that the DFT is not the most suitable tool for this type of analysis, since, by definition, this tool is useful for processing stationary signals. Taking that in...

  15. Controlled Acoustic Bass System (CABS) A Method to Achieve Uniform Sound Field Distribution at Low Frequencies in Rectangular Rooms

    DEFF Research Database (Denmark)

    Celestinos, Adrian; Nielsen, Sofus Birkedal

    2008-01-01

    The sound field produced by loudspeakers at low frequencies in small- and medium-size rectangular listening rooms is highly nonuniform due to the multiple reflections and diffractions of sound on the walls and different objects in the room. A new method, called controlled acoustic bass system (CA......-frequency range. CABS has been simulated and measured in two different standard listening rooms with satisfactory results....

  16. Cumulative effective dose associated with radiography and CT of adolescents with spinal injuries.

    Science.gov (United States)

    Lemburg, Stefan P; Peters, Soeren A; Roggenland, Daniela; Nicolas, Volkmar; Heyer, Christoph M

    2010-12-01

    The purpose of this study was to analyze the quantity and distribution of cumulative effective doses in diagnostic imaging of adolescents with spinal injuries. At a level 1 trauma center from July 2003 through June 2009, imaging procedures during initial evaluation and hospitalization and after discharge of all patients 10-20 years old with spinal fractures were retrospectively analyzed. The cumulative effective doses for all imaging studies were calculated, and the doses to patients with spinal injuries who had multiple traumatic injuries were compared with the doses to patients with spinal injuries but without multiple injuries. The significance level was set at 5%. Imaging studies of 72 patients (32 with multiple injuries; average age, 17.5 years) entailed a median cumulative effective dose of 18.89 mSv. Patients with multiple injuries had a significantly higher total cumulative effective dose (29.70 versus 10.86 mSv, p cumulative effective dose to multiple injury patients during the initial evaluation (18.39 versus 2.83 mSv, p cumulative effective dose. Adolescents with spinal injuries receive a cumulative effective dose equal to that of adult trauma patients and nearly three times that of pediatric trauma patients. Areas of focus in lowering cumulative effective dose should be appropriate initial estimation of trauma severity and careful selection of CT scan parameters.

  17. Density distribution of currents induced inside the brain in the head part of the human model exposed to power frequency electric field

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Atsuo [Yongo National Collage of Technology (Japan); Isaka, Katsuo [University of Tokushima (Japan)

    1999-07-01

    The health effect of the weak current induced in the human body as a result of the interaction between human body and power frequency electric fields has been investigated. However, the current density inside the head part tissues of the human body exposed to the electric fields has rarely been discussed. In this paper, the finite element method is applied to the analysis of the current density distribution of the head part composed of scalp, skull, cerebrospinal liquid and brain tissues. The basic characteristics of the current density distributions of the brain in the asymmetrical human model have been made clear. (author)

  18. Comparative analysis of frequency and noise characteristics of Fabry – Perot and distributed feedback laser diodes with external optical injection locking

    Energy Technology Data Exchange (ETDEWEB)

    Afonenko, A A; Dorogush, E S [Belarusian State University, Minsk (Belarus); Malyshev, S A; Chizh, A L [B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk (Belarus)

    2015-11-30

    Using a system of coupled travelling wave equations, in the small-signal regime we analyse frequency and noise characteristics of index- or absorption-coupled distributed feedback laser diodes, as well as of Fabry – Perot (FP) laser diodes. It is shown that the weakest dependence of the direct modulation efficiency on the locking frequency in the regime of strong external optical injection locking is exhibited by a FP laser diode formed by highly reflective and antireflective coatings on the end faces of a laser structure. A reduction in the dependence of output characteristics of the laser diode on the locking frequency can be attained by decreasing the reflection coefficient of the antireflective FP mirror. (control of laser radiation parameters)

  19. Optimal Scheduling of Distributed Energy Resources and Responsive Loads in Islanded Microgrids Considering Voltage and Frequency Security Constraints

    DEFF Research Database (Denmark)

    Vahedipour-Dahraie, Mostafa; Najafi, Hamid Reza; Anvari-Moghaddam, Amjad

    2018-01-01

    in islanded MGs with regard to voltage and frequency security constraints. Based on the proposed model, scheduling of the controllable units in both supply and demand sides is done in a way not only to maximize the expected profit of MG operator (MGO), but also to minimize the energy payments of customers...... on the system’s performance in terms of voltage and frequency stability. Moreover, optimal coordination of DERs and responsive loads can increase the expected profit of MGO significantly. The effectiveness of the proposed scheduling approach is verified on an islanded MG test system over a 24-h period....

  20. Predicting Cumulative Incidence Probability: Marginal and Cause-Specific Modelling

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    2005-01-01

    cumulative incidence probability; cause-specific hazards; subdistribution hazard; binomial modelling......cumulative incidence probability; cause-specific hazards; subdistribution hazard; binomial modelling...

  1. Predicting Cumulative Incidence Probability by Direct Binomial Regression

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...

  2. Managing cumulative impacts: A key to sustainability?

    Energy Technology Data Exchange (ETDEWEB)

    Hunsaker, C.T.

    1994-12-31

    This paper addresses how science can be more effectively used in creating policy to manage cumulative effects on ecosystems. The paper focuses on the scientific techniques that we have to identify and to assess cumulative impacts on ecosystems. The term ``sustainable development`` was brought into common use by the World Commission on Environment and Development (The Brundtland Commission) in 1987. The Brundtland Commission report highlighted the need to simultaneously address developmental and environmental imperatives simultaneously by calling for development that ``meets the needs of the present generation without compromising the needs of future generations.`` We cannot claim to be working toward sustainable development until we can quantitatively assess cumulative impacts on the environment: The two concepts are inextricibally linked in that the elusiveness of cumulative effects likely has the greatest potential of keeping us from achieving sustainability. In this paper, assessment and management frameworks relevant to cumulative impacts are discussed along with recent literature on how to improve such assessments. When possible, examples are given for marine ecosystems.

  3. Experiences with non-intrusive monitoring of distribution transformers based on the on-line frequency response

    Directory of Open Access Journals (Sweden)

    Eduardo Gomez Luna

    2015-01-01

    Full Text Available The following article presents the results obtained in experiences that use the Impulse Frequency Response Analysis (IFRA method with a transformer in service. The IFRA method has been implemented in order to transform the transient signals to the frequency domain using Discrete Fourier Transform (DFT. However, it can be considered that the DFT is not the most suitable tool for this type of analysis, since, by definition, this tool is useful for processing stationary signals. Taking that into consideration, the analysis of transient signals could be hypothetically improved by using continuous wavelet transform (CWT, given their variable time/frequency resolution. The analysis of transient signals in Wavelet domain has improved the repeatability of the frequency response curves, as it has been ob-served in experimental results. The proposed on-line IFRA method, based on Wavelet transform, was validated under load and no-load conditions on a 150 kVA three-phase transformer 13200/225 Volts, in the Campus of the Universidad del Valle, Cali, Colombia.

  4. A Corpus-Based Lexical Study on Frequency and Distribution of Coxhead's Awl Word Families in Medical Research Articles (RAs)

    Science.gov (United States)

    Chen, Qi; Guang-Chun, Ge

    2007-01-01

    We conducted a lexical study on the word frequency and the text coverage of the 570 word families from Coxhead's Academic Word List (AWL) in medical research articles (RAs) based on a corpus of 50 medical RAs written in English with 190425 running words. By computer analysis, we found that the text coverage of the AWL words accounted for around…

  5. State updating of a distributed hydrological model with Ensemble Kalman Filtering: effects of updating frequency and observation network density on forecast accuracy

    Directory of Open Access Journals (Sweden)

    O. Rakovec

    2012-09-01

    Full Text Available This paper presents a study on the optimal setup for discharge assimilation within a spatially distributed hydrological model. The Ensemble Kalman filter (EnKF is employed to update the grid-based distributed states of such an hourly spatially distributed version of the HBV-96 model. By using a physically based model for the routing, the time delay and attenuation are modelled more realistically. The discharge and states at a given time step are assumed to be dependent on the previous time step only (Markov property.

    Synthetic and real world experiments are carried out for the Upper Ourthe (1600 km2, a relatively quickly responding catchment in the Belgian Ardennes. We assess the impact on the forecasted discharge of (1 various sets of the spatially distributed discharge gauges and (2 the filtering frequency. The results show that the hydrological forecast at the catchment outlet is improved by assimilating interior gauges. This augmentation of the observation vector improves the forecast more than increasing the updating frequency. In terms of the model states, the EnKF procedure is found to mainly change the pdfs of the two routing model storages, even when the uncertainty in the discharge simulations is smaller than the defined observation uncertainty.

  6. Perspectives on cumulative risks and impacts.

    Science.gov (United States)

    Faust, John B

    2010-01-01

    Cumulative risks and impacts have taken on different meanings in different regulatory and programmatic contexts at federal and state government levels. Traditional risk assessment methodologies, with considerable limitations, can provide a framework for the evaluation of cumulative risks from chemicals. Under an environmental justice program in California, cumulative impacts are defined to include exposures, public health effects, or environmental effects in a geographic area from the emission or discharge of environmental pollution from all sources, through all media. Furthermore, the evaluation of these effects should take into account sensitive populations and socioeconomic factors where possible and to the extent data are available. Key aspects to this potential approach include the consideration of exposures (versus risk), socioeconomic factors, the geographic or community-level assessment scale, and the inclusion of not only health effects but also environmental effects as contributors to impact. Assessments of this type extend the boundaries of the types of information that toxicologists generally provide for risk management decisions.

  7. Cumulative Culture and Future Thinking: Is Mental Time Travel a Prerequisite to Cumulative Cultural Evolution?

    Science.gov (United States)

    Vale, G. L.; Flynn, E. G.; Kendal, R. L.

    2012-01-01

    Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution…

  8. A comparative study of dose distribution of a high-energy electron beam and chromosome aberration frequencies

    International Nuclear Information System (INIS)

    Matsubara, Sho; Kuwabara, Yuji; Horiuch, Junichi; Suzuki, Soji; Hoshina, Masao; Kato, Tsuguhisa

    1986-01-01

    Peripheral blood was exposed to a 14 MeV electron beam in a plastic tube set in a test-tube stand immersed in a water tank. The chromosome aberration frequencies induced by irradiation of about 95% of peak dose at a depth of 31 mm were found to be higher in value than those induced at a depth of 17 mm where the peak dose had been determined physically. Three gray of irradiation given to whole blood in the presence of contrast medium gave rise to a slight enhancement of radiation-induced chromosome aberration frequencies in the lymphocytes exposed at a depth of 17 mm, but a slight decrease at 31 mm. (author)

  9. Application of Linear Quadratic Gaussian and Coefficient Diagram Techniques to Distributed Load Frequency Control of Power Systems

    Directory of Open Access Journals (Sweden)

    Tarek Hassan Mohamed

    2015-12-01

    Full Text Available This paper presented both the linear quadratic Gaussian technique (LQG and the coefficient diagram method (CDM as load frequency controllers in a multi-area power system to deal with the problem of variations in system parameters and load demand change. The full states of the system including the area frequency deviation have been estimated using the Kalman filter technique. The efficiency of the proposed control method has been checked using a digital simulation. Simulation results indicated that, with the proposed CDM + LQG technique, the system is robust in the face of parameter uncertainties and load disturbances. A comparison between the proposed technique and other schemes is carried out, confirming the superiority of the proposed CDM + LQG technique.

  10. Cumulative effects of wind turbines. A guide to assessing the cumulative effects of wind energy development

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This guidance provides advice on how to assess the cumulative effects of wind energy developments in an area and is aimed at developers, planners, and stakeholders interested in the development of wind energy in the UK. The principles of cumulative assessment, wind energy development in the UK, cumulative assessment of wind energy development, and best practice conclusions are discussed. The identification and assessment of the cumulative effects is examined in terms of global environmental sustainability, local environmental quality and socio-economic activity. Supplementary guidance for assessing the principle cumulative effects on the landscape, on birds, and on the visual effect is provided. The consensus building approach behind the preparation of this guidance is outlined in the annexes of the report.

  11. Stabilization of the Propagation Delay in Fiber Optics in a Frequency Distribution Link Using Electronic Delay Lines: First Measurement Results

    Science.gov (United States)

    2010-11-01

    of Time and Frequency ul. Elektoralna 2, 00-139 Warszawa , Poland Tel: +48 22 5819156, E-mail: timegum@gum.gov.pl Łukasz Śliwczyński, Przemysław...Elektoralna 2, 00-139 Warszawa , Poland 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S

  12. Distribution

    Science.gov (United States)

    John R. Jones

    1985-01-01

    Quaking aspen is the most widely distributed native North American tree species (Little 1971, Sargent 1890). It grows in a great diversity of regions, environments, and communities (Harshberger 1911). Only one deciduous tree species in the world, the closely related Eurasian aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911)....

  13. The quest for narrow e{sup +}e{sup -} cumulative energy distributions heavy ion collisions. The GSI e{sup +}e{sup -} puzzle; Die Suche nach schmalen e{sup +}e{sup -} Summenenergieverteilungen in Schwerionenkollisionen. Das GSI e{sup +}e{sup -}-Puzzle

    Energy Technology Data Exchange (ETDEWEB)

    Ganz, R.

    1995-12-01

    The examination of electron-positron pairs which are emitted in heavy-ion collisions at the Coulomb barrier was continued with the newly designed EPoS II spectrometer at the UNILAC accelerator. The objective of the experiments was to further analyse the narrow line structures in the positron-electron cumulative energy distributions, which were observed in preceding measurements examining the collision systems U 238 + Th 232 and U 238 + Ta181 with the EPOS I spectrometer. By means of a reproduction experiment, the existence of the lines was statistically verified relying on a large data pool. [Deutsch] Die Untersuchung von Elektron- Positron Paaren, die bei Schwerionenkol lisionen an der Coulombbarriere emittiert werden, wurde mit dem neu kon zipierten EPoS II Spektrometer am UNILAC- Beschleuniger fortgesetzt. D ie Motivation der Experimente war die weitere Untersuchung der schmale n Linienstrukturen in den Positron- Elektron- Summenenergieverteilunge n, die in vorangegangenen Messungen der Stosssysteme U 238+ Th 232 un d U 238+ Ta 181 mit dem EPOS I Spektrometer beobachtet wurden. Durch ei ne Reproduktion wurde die Existenz der Linien anhand einer grossen Date nmenge statistisch sicher geprueft.

  14. Passenger arrival and waiting time distributions dependent on train service frequency and station characteristics: A smart card data analysis

    DEFF Research Database (Denmark)

    Ingvardson, Jesper Bláfoss; Nielsen, Otto Anker; Raveau, Sebastián

    2018-01-01

    Waiting time at public transport stops is perceived by passengers to be more onerous than in-vehicle time, hence it strongly influences the attractiveness and use of public transport. Transport models traditionally assume that average waiting times are half the service headway by assuming random...... Copenhagen Area covering metro, suburban, and regional rail stations thereby giving a range of service headways from 2 to 60 min. It was shown that the proposed mixture distribution is superior to other distributions proposed in the literature. This can improve waiting time estimations in public transport...

  15. Preliminary survey on the distribution of medical equipment and frequency of diagnostic and therapeutic procedures in Brazil: a contribution to the UNSCEAR report

    International Nuclear Information System (INIS)

    Biazotto, Bruna; Taboza de Oliveira, Alexandre; Baptista de Freitas, Marcelo

    2008-01-01

    Information about Brazil published in the UNSCEAR 2000 report are still scarce when compared to others countries. In this study, a survey on the distribution of medical equipment (X-ray generators, ultrasound, CT and MRI scanners, nuclear medicine equipment and teletherapy and brachytherapy units) and frequency of diagnostic and therapeutic procedures at the various Brazilian States was carried out. The overall information was obtained from a national database supported by the Brazilian Ministry of Health through the Computer Science Department of the National Health System (SUS - Sistema Unico de Saude). The distribution of equipment and the annual frequency of each type of procedure were analyzed considering the five geographical regions that form the country and their respective population. Temporal and regional trends in the annual frequency of procedures for 2000-2007 were also summarized in this study. National annual frequencies for the total of all medical X-ray examinations (259.0 examinations per 1000 population) were evaluated. Some examples can be given from chest, mammography and CT examinations: 67.4, 30.2 and 7.2 per 1000 population, respectively. In addition, annual frequencies for other modalities of diagnostic imaging have also been estimated: 61.5, 1.6 and 1.4 per 1000 population for ultrasound, nuclear medicine and MRI procedures, respectively. A total of 38.7 therapeutic procedures per 1000 population (teletherapy and brachytherapy) are annually performed in the country. The health services localized in Brazil comprised a total number of 253.1 diagnostic imaging equipment per million population, without considering dental X-ray. Amongst them, X-ray equipment used in common radiological examinations (chest, skull, spine, etc.) stands for 39% (97.7 per million). As expected, a significant decrease in the offer of equipment is observed when technologically more sophisticated equipment is concerned: magnetic resonance (3.5 per million), gamma

  16. Effect of Sertraline on Current-Source Distribution of the High Beta Frequency Band: Analysis of Electroencephalography under Audiovisual Erotic Stimuli in Healthy, Right-Handed Males.

    Science.gov (United States)

    Lee, Seung Hyun; Hyun, Jae Seog; Kwon, Oh-Young

    2010-08-01

    The purpose of this study was to examine the cerebral changes in high beta frequency oscillations (22-30 Hz) induced by sertraline and by audiovisual erotic stimuli in healthy adult males. Scalp electroencephalographies (EEGs) were conducted twice in 11 healthy, right-handed males, once before sertraline intake and again 4 hours thereafter. The EEGs included four sessions recorded sequentially while the subjects were resting, watching a music video, resting, and watching an erotic video for 3 minutes, 5 minutes, 3 minutes, and 5 minutes, respectively. We performed frequency-domain analysis using the EEGs with a distributed model of current-source analysis. The statistical nonparametric maps were obtained from the sessions of watching erotic and music videos (perotic stimuli decreased the current-source density of the high beta frequency band in the middle frontal gyrus, the precentral gyrus, the postcentral gyrus, and the supramarginal gyrus of the left cerebral hemisphere in the baseline EEGs taken before sertraline intake (perotic stimuli did not induce any changes in current-source distribution of the brain 4 hours after sertraline intake. It is speculated that erotic stimuli may decrease the function of the middle frontal gyrus, the precentral gyrus, the postcentral gyrus, and the supramarginal gyrus of the left cerebral hemisphere in healthy adult males. This change may debase the inhibitory control of the brain against erotic stimuli. Sertraline may reduce the decrement in inhibitory control.

  17. Distribution and frequency of Bru1, a major brown rust resistance gene, in the sugarcane world collection

    Science.gov (United States)

    Brown rust, caused by Puccinia melanocephala, is an important disease of sugarcane worldwide. Molecular markers for a major brown rust resistance gene, Bru1, were used to screen a total of 1,282 clones in the World Collection of Sugarcane and Related Grasses (WCSRG) to determine the distribution and...

  18. Multiparty correlation measure based on the cumulant

    International Nuclear Information System (INIS)

    Zhou, D. L.; Zeng, B.; Xu, Z.; You, L.

    2006-01-01

    We propose a genuine multiparty correlation measure for a multiparty quantum system as the trace norm of the cumulant of the state. The legitimacy of our multiparty correlation measure is explicitly demonstrated by proving it satisfies the five basic conditions required for a correlation measure. As an application we construct an efficient algorithm for the calculation of our measures for all stabilizer states

  19. Decision analysis with cumulative prospect theory.

    Science.gov (United States)

    Bayoumi, A M; Redelmeier, D A

    2000-01-01

    Individuals sometimes express preferences that do not follow expected utility theory. Cumulative prospect theory adjusts for some phenomena by using decision weights rather than probabilities when analyzing a decision tree. The authors examined how probability transformations from cumulative prospect theory might alter a decision analysis of a prophylactic therapy in AIDS, eliciting utilities from patients with HIV infection (n = 75) and calculating expected outcomes using an established Markov model. They next focused on transformations of three sets of probabilities: 1) the probabilities used in calculating standard-gamble utility scores; 2) the probabilities of being in discrete Markov states; 3) the probabilities of transitioning between Markov states. The same prophylaxis strategy yielded the highest quality-adjusted survival under all transformations. For the average patient, prophylaxis appeared relatively less advantageous when standard-gamble utilities were transformed. Prophylaxis appeared relatively more advantageous when state probabilities were transformed and relatively less advantageous when transition probabilities were transformed. Transforming standard-gamble and transition probabilities simultaneously decreased the gain from prophylaxis by almost half. Sensitivity analysis indicated that even near-linear probability weighting transformations could substantially alter quality-adjusted survival estimates. The magnitude of benefit estimated in a decision-analytic model can change significantly after using cumulative prospect theory. Incorporating cumulative prospect theory into decision analysis can provide a form of sensitivity analysis and may help describe when people deviate from expected utility theory.

  20. Cumulative watershed effects: a research perspective

    Science.gov (United States)

    Leslie M. Reid; Robert R. Ziemer

    1989-01-01

    A cumulative watershed effect (CWE) is any response to multiple land-use activities that is caused by, or results in, altered watershed function. The CWE issue is politically defined, as is the significance of particular impacts. But the processes generating CWEs are the traditional focus of geomorphology and ecology, and have thus been studied for decades. The CWE...

  1. Sheet beam model for intense space charge: Application to Debye screening and the distribution of particle oscillation frequencies in a thermal equilibrium beam

    Directory of Open Access Journals (Sweden)

    Steven M. Lund

    2011-05-01

    Full Text Available A one-dimensional Vlasov-Poisson model for sheet beams is reviewed and extended to provide a simple framework for analysis of space-charge effects. Centroid and rms envelope equations including image-charge effects are derived and reasonable parameter equivalences with commonly employed 2D transverse models of unbunched beams are established. This sheet-beam model is then applied to analyze several problems of fundamental interest. A sheet-beam thermal equilibrium distribution in a continuous focusing channel is constructed and shown to have analogous properties to two- and three-dimensional thermal equilibrium models in terms of the equilibrium structure and Debye screening properties. The simpler formulation for sheet beams is exploited to explicitly calculate the distribution of particle oscillation frequencies within a thermal equilibrium beam. It is shown that as space-charge intensity increases, the frequency distribution becomes broad, suggesting that beams with strong space-charge can have improved stability relative to beams with weak space-charge.

  2. An evaluation paradigm for cumulative impact analysis

    Science.gov (United States)

    Stakhiv, Eugene Z.

    1988-09-01

    Cumulative impact analysis is examined from a conceptual decision-making perspective, focusing on its implicit and explicit purposes as suggested within the policy and procedures for environmental impact analysis of the National Environmental Policy Act of 1969 (NEPA) and its implementing regulations. In this article it is also linked to different evaluation and decision-making conventions, contrasting a regulatory context with a comprehensive planning framework. The specific problems that make the application of cumulative impact analysis a virtually intractable evaluation requirement are discussed in connection with the federal regulation of wetlands uses. The relatively familiar US Army Corps of Engineers' (the Corps) permit program, in conjunction with the Environmental Protection Agency's (EPA) responsibilities in managing its share of the Section 404 regulatory program requirements, is used throughout as the realistic context for highlighting certain pragmatic evaluation aspects of cumulative impact assessment. To understand the purposes of cumulative impact analysis (CIA), a key distinction must be made between the implied comprehensive and multiobjective evaluation purposes of CIA, promoted through the principles and policies contained in NEPA, and the more commonly conducted and limited assessment of cumulative effects (ACE), which focuses largely on the ecological effects of human actions. Based on current evaluation practices within the Corps' and EPA's permit programs, it is shown that the commonly used screening approach to regulating wetlands uses is not compatible with the purposes of CIA, nor is the environmental impact statement (EIS) an appropriate vehicle for evaluating the variety of objectives and trade-offs needed as part of CIA. A heuristic model that incorporates the basic elements of CIA is developed, including the idea of trade-offs among social, economic, and environmental protection goals carried out within the context of environmental

  3. Plasminogen Activator Inhibitor-1 (PAI-1) gene 4G/5G alleles frequency distribution in the Lebanese population.

    Science.gov (United States)

    Shammaa, Dina M R; Sabbagh, Amira S; Taher, Ali T; Zaatari, Ghazi S; Mahfouz, Rami A R

    2008-09-01

    Plasminogen activator inhibitor-1 (PAI-1) is an inhibitor of fibrinolysis. Increased plasma PAI-1 levels play an essential role in the pathogenesis of cardiovascular risk and other diseases associated with thrombosis. The 4G/5G polymorphism of the PAI-1 promoter region has been extensively studied in different populations. We studied 160 healthy unrelated Lebanese individuals using a reverse hybridization PCR assay to detect the 5G/5G, 4G/5G and, 4G/4G genotypes of the PAI-1 gene and the frequencies of the 4G and 5G alleles. We found that 4G/5G genotype was the most prevalent (45.6%) followed by 5G/5G (36.9%) and 4G/4G (17.5%). The frequencies of the 4G and 5G alleles were calculated to be 0.403 and 0.597, respectively. Compared to other ethnic communities, the Lebanese population was found to harbour a relatively high prevalence of the rare 4G allele. This, in turn, may predispose this population to develop cardiovascular diseases and other thrombotic clinical conditions. This study aids to enhance our understanding of the genetic features of the Lebanese population.

  4. Asian population frequencies and haplotype distribution of killer cell immunoglobulin-like receptor (KIR) genes among Chinese, Malay, and Indian in Singapore.

    Science.gov (United States)

    Lee, Yi Chuan; Chan, Soh Ha; Ren, Ee Chee

    2008-11-01

    Killer cell immunoglobulin-like receptors (KIR) gene frequencies have been shown to be distinctly different between populations and contribute to functional variation in the immune response. We have investigated KIR gene frequencies in 370 individuals representing three Asian populations in Singapore and report here the distribution of 14 KIR genes (2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) with two pseudogenes (2DP1, 3DP1) among Singapore Chinese (n = 210); Singapore Malay (n = 80), and Singapore Indian (n = 80). Four framework genes (KIR3DL3, 3DP1, 2DL4, 3DL2) and a nonframework pseudogene 2DP1 were detected in all samples while KIR2DS2, 2DL2, 2DL5, and 2DS5 had the greatest significant variation across the three populations. Fifteen significant linkage patterns, consistent with associations between genes of A and B haplotypes, were observed. Eighty-four distinct KIR profiles were determined in our populations, 38 of which had not been described in other populations. KIR haplotype studies were performed using nine Singapore Chinese families comprising 34 individuals. All genotypes could be resolved into corresponding pairs of existing haplotypes with eight distinct KIR genotypes and eight different haplotypes. The haplotype A2 with frequency of 63.9% was dominant in Singapore Chinese, comparable to that reported in Korean and Chinese Han. The A haplotypes predominate in Singapore Chinese, with ratio of A to B haplotypes of approximately 3:1. Comparison with KIR frequencies in other populations showed that Singapore Chinese shared similar distributions with Chinese Han, Japanese, and Korean; Singapore Indian was found to be comparable with North Indian Hindus while Singapore Malay resembled the Thai.

  5. Highly efficient single-pass frequency doubling of a continuous-wave distributed feedback laser diode using a PPLN waveguide crystal at 488 nm.

    Science.gov (United States)

    Jechow, Andreas; Schedel, Marco; Stry, Sandra; Sacher, Joachim; Menzel, Ralf

    2007-10-15

    A continuous-wave distributed feedback diode laser emitting at 976 nm was frequency doubled by the use of a periodically poled lithium niobate waveguide crystal with a channel size of 3 microm x 5 microm and an interaction length of 10 mm. A laser to waveguide coupling efficiency of 75% could be achieved resulting in 304 mW of incident infrared light inside the waveguide. Blue laser light emission of 159 mW at 488 nm has been generated, which equals to a conversion efficiency of 52%. The resulting wall plug efficiency was 7.4%.

  6. FREQUENCY AND DISTRIBUTION OF ABO & RH BLOOD GROUP IN BILASPUR DISTRICT OF CHHATTISGARH STATE : A STUDY FROM MEDICAL COLLEGE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Bhanu Pratap

    2015-07-01

    Full Text Available BACKGROUND : Approximate 30 blood group systems have discovered and more than 400 erythrocytes antigens are identified. Blood group ABO and Rh are most important among all other blood group systems in transfusion service practices. The frequency of four major blood gr oup s namely A, B, O, AB with Rh Positive and Negative varies in different population of the world and differ also in region and race wise. MATERIAL AND METHOD : This 5 years retrospective study was conducted at Blood Bank of a Medical college Hospital of Bi laspur in Northern Chhattisgarh, catering the 1/3 population of state. Data were collected from the Blood Bank Grouping record from the period of January 2010 to December 2014. Blood group of blood donors and patients were determined by Monoclonal Anti Ser a by slide agglutinations tests. Rare case and difficult case were examined by test tube agglutination method and Matrix Gel System of Tulip. RESULT AND CONCLUSIO N: 31973 subjects were examined for blood group during observation period, Out of these 31092( 97.25% were male and 881 (2.75% were female. The frequency of blood group B in these populations was 11007 (34.42% (33.36% Rh Positive and 1.06% Rh Negative Followed by O were 10864 (33.97% (33.33% Rh Positive and 0.64% Rh Negative, A was 9113 (28.50 % (27.99 % Rh Positive and 0.51% Rh Negative and AB was 989 (3.11% (3.01% Rh Positive and 0.1% Rh Negative. Rhesus group Rh Positive were 31242 (97.7 % and Rh Negative were 731 (2.3 %.

  7. Spatial distribution and temporal variations of occurrence frequency of lightning whistlers observed by VLF/WBA onboard Akebono

    Science.gov (United States)

    Oike, Yuta; Kasahara, Yoshiya; Goto, Yoshitaka

    2014-09-01

    We statistically analyzed lightning whistlers detected from the analog waveform data below 15 kHz observed by the VLF instruments onboard Akebono. We examined the large amount of data obtained at Uchinoura Space Center in Japan for 22 years from 1989 to 2010. The lightning whistlers were mainly observed inside the L shell region below 2. Seasonal dependence of the occurrence frequency of lightning whistlers has two peaks around July to August and December to January. As lightning is most active in summer, in general, these two peaks correspond to summer in the Northern and Southern Hemispheres, respectively. Diurnal variation of the occurrence frequency showed that lightning whistlers begin to increase in the early evening and remain at a high-occurrence level through the night with a peak around 21 in magnetic local time (MLT). This peak shifts toward nightside compared with lightning activity, which begins to rise around noon and peaks in the late afternoon. This trend is supposed to be caused by attenuation of VLF wave in the ionosphere in the daytime. Comparison study with the ground-based observation revealed consistent results, except that the peak of the ground-based observation appeared after midnight while our measurements obtained by Akebono was around 21 in MLT. This difference is explained qualitatively in terms that lightning whistlers measured at the ground station passed through the ionosphere twice above both source region and the ground station. These facts provide an important clue to evaluate quantitatively the absorption effect of lightning whistler in the ionosphere.

  8. Frequency and distribution of primary site among gender minority cancer patients: An analysis of U.S. national surveillance data.

    Science.gov (United States)

    Nash, Rebecca; Ward, Kevin C; Jemal, Ahmedin; Sandberg, David E; Tangpricha, Vin; Goodman, Michael

    2018-03-09

    Transgender people and persons with disorders of sex development (DSD) are two separate categories of gender minorities, each characterized by unique cancer risk factors. Although cancer registry data typically include only two categories of sex, registrars have the option of indicating that a patient is transgender or has a DSD. Data for primary cancer cases in 46 states and the District of Columbia were obtained from the North American Association of Central Cancer Registries (NAACCR) database for the period 1995-2013. The distributions of primary sites and categories of cancers with shared risk factors were examined separately for transgender and DSD patients and compared to the corresponding distributions in male and female cancer patients. Proportional incidence ratios were calculated by dividing the number of observed cases by the number of expected cases. Expected cases were calculated based on the age- and year of diagnosis-specific proportions of cases in each cancer category observed among male and female patients. Transgender patients have significantly elevated proportional incidence ratios (95% confidence intervals) for viral infection induced cancers compared to either males (2.3; 2.0-2.7) or females (3.3; 2.8-3.7). Adult DSD cancer patients have a similar distribution of primary sites compared to male or female patients but DSD children with cancer have ten times more cases of testicular malignancies than expected (95% confidence interval: 4.7-20). The proportions of certain primary sites and categories of malignancies among transgender and DSD cancer patients are different from the proportions observed for male or female patients. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Distribution Of 15N Fertilizer Added To Sandy Soil Under Drip Irrigation System As Affected By Irrigation Frequencies

    International Nuclear Information System (INIS)

    GADALLA, A.M.; GALAL, Y.G.M.; EL-GENDY, R.W.; ISMAIL, M.M.; EL-DEGWY, S.M.; KASSAB, M.F.

    2009-01-01

    Neutron moisture meter and stable nitrogen isotope ( 15 N) were used to follow horizontal and vertical water movement and N-fertilizer added to soil before and after irrigation. The data indicated that soil moisture distribution and values of total hydraulic potential depend on soil moisture content. Characterization of nitrogen in soil for all sites around the emitter indicated spatial variability with different soil depths due to leaching and volatilization processes. Moreover, water movement and flow direction greatly were characterized by active evaporation depth which was 30 cm.

  10. State updating of a distributed hydrological model with Ensemble Kalman Filtering: Effects of updating frequency and observation network density on forecast accuracy

    Science.gov (United States)

    Rakovec, O.; Weerts, A.; Hazenberg, P.; Torfs, P.; Uijlenhoet, R.

    2012-12-01

    This paper presents a study on the optimal setup for discharge assimilation within a spatially distributed hydrological model (Rakovec et al., 2012a). The Ensemble Kalman filter (EnKF) is employed to update the grid-based distributed states of such an hourly spatially distributed version of the HBV-96 model. By using a physically based model for the routing, the time delay and attenuation are modelled more realistically. The discharge and states at a given time step are assumed to be dependent on the previous time step only (Markov property). Synthetic and real world experiments are carried out for the Upper Ourthe (1600 km2), a relatively quickly responding catchment in the Belgian Ardennes. The uncertain precipitation model forcings were obtained using a time-dependent multivariate spatial conditional simulation method (Rakovec et al., 2012b), which is further made conditional on preceding simulations. We assess the impact on the forecasted discharge of (1) various sets of the spatially distributed discharge gauges and (2) the filtering frequency. The results show that the hydrological forecast at the catchment outlet is improved by assimilating interior gauges. This augmentation of the observation vector improves the forecast more than increasing the updating frequency. In terms of the model states, the EnKF procedure is found to mainly change the pdfs of the two routing model storages, even when the uncertainty in the discharge simulations is smaller than the defined observation uncertainty. Rakovec, O., Weerts, A. H., Hazenberg, P., Torfs, P. J. J. F., and Uijlenhoet, R.: State updating of a distributed hydrological model with Ensemble Kalman Filtering: effects of updating frequency and observation network density on forecast accuracy, Hydrol. Earth Syst. Sci. Discuss., 9, 3961-3999, doi:10.5194/hessd-9-3961-2012, 2012a. Rakovec, O., Hazenberg, P., Torfs, P. J. J. F., Weerts, A. H., and Uijlenhoet, R.: Generating spatial precipitation ensembles: impact of

  11. Energy distributions of an ion in a radio-frequency trap immersed in a buffer gas under the influence of additional external forces

    Science.gov (United States)

    Rouse, I.; Willitsch, S.

    2018-04-01

    An ion held in a radio-frequency trap interacting with a uniform buffer gas of neutral atoms develops a steady-state energy distribution characterized by a power-law tail at high energies instead of the exponential decay characteristic of thermal equilibrium. We have previously shown that the Tsallis statistics frequently used as an empirical model for this distribution is a good approximation when the ion is heated due to a combination of micromotion interruption and exchange of kinetic energy with the buffer gas [Rouse and Willitsch, Phys. Rev. Lett. 118, 143401 (2017), 10.1103/PhysRevLett.118.143401]. Here, we extend our treatment to include the heating due to additional motion of the ion caused by external forces, including the "excess micromotion" induced by uniform electric fields and rf phase offsets. We show that this also leads to a Tsallis distribution with a potentially different power-law exponent from that observed in the absence of this additional forced motion, with the difference increasing as the ratio of the mass of the neutral atoms to that of the ion decreases. Our results indicate that unless the excess micromotion is minimized to a very high degree, then even a system with very light neutrals and a heavy ion does not exhibit a thermal distribution.

  12. Complexity and demographic explanations of cumulative culture.

    Science.gov (United States)

    Querbes, Adrien; Vaesen, Krist; Houkes, Wybo

    2014-01-01

    Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

  13. Complexity and demographic explanations of cumulative culture.

    Directory of Open Access Journals (Sweden)

    Adrien Querbes

    Full Text Available Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

  14. Conceptual models for cumulative risk assessment.

    Science.gov (United States)

    Linder, Stephen H; Sexton, Ken

    2011-12-01

    In the absence of scientific consensus on an appropriate theoretical framework, cumulative risk assessment and related research have relied on speculative conceptual models. We argue for the importance of theoretical backing for such models and discuss 3 relevant theoretical frameworks, each supporting a distinctive "family" of models. Social determinant models postulate that unequal health outcomes are caused by structural inequalities; health disparity models envision social and contextual factors acting through individual behaviors and biological mechanisms; and multiple stressor models incorporate environmental agents, emphasizing the intermediary role of these and other stressors. The conclusion is that more careful reliance on established frameworks will lead directly to improvements in characterizing cumulative risk burdens and accounting for disproportionate adverse health effects.

  15. Childhood Cumulative Risk and Later Allostatic Load

    DEFF Research Database (Denmark)

    Doan, Stacey N; Dich, Nadya; Evans, Gary W

    2014-01-01

    State, followed for 8 years (between the ages 9 and 17). Poverty- related stress was computed using the cumulative risk approach, assessing stressors across 9 domains, including environmental, psychosocial, and demographic factors. Allostatic load captured a range of physiological responses, including......Objective: The present study investigated the long-term impact of exposure to poverty-related stressors during childhood on allostatic load, an index of physiological dysregulation, and the potential mediating role of substance use. Method: Participants (n = 162) were rural children from New York...... cardiovascular, hypothalamic pituitary adrenal axis, sympathetic adrenal medullary system, and metabolic activity. Smoking and alcohol/drug use were tested as mediators of the hypothesized childhood risk-adolescent allostatic load relationship. Results: Cumulative risk exposure at age 9 predicted increases...

  16. The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations.

    LENUS (Irish Health Repository)

    Flanagan, J M

    2010-02-01

    Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

  17. Fuzzy set theory for cumulative trauma prediction

    OpenAIRE

    Fonseca, Daniel J.; Merritt, Thomas W.; Moynihan, Gary P.

    2001-01-01

    A widely used fuzzy reasoning algorithm was modified and implemented via an expert system to assess the potential risk of employee repetitive strain injury in the workplace. This fuzzy relational model, known as the Priority First Cover Algorithm (PFC), was adapted to describe the relationship between 12 cumulative trauma disorders (CTDs) of the upper extremity, and 29 identified risk factors. The algorithm, which finds a suboptimal subset from a group of variables based on the criterion of...

  18. Sikap Kerja Duduk Terhadap Cumulative Trauma Disorder

    OpenAIRE

    Rahmawati, Yulita; Sugiharto, -

    2011-01-01

    Permasalahan yang diteliti adalah adakah hubungan antara sikap kerja duduk dengan kejadian Cumulative Trauma Disorder (CTD) pada pekerja bagian pengamplasan di PT. Geromar Jepara. Tujuan yang ingin dicapai adalah untuk mengetahui hubungan antara sikap kerja duduk dengan kejadian CTD pada pekerja bagian pengamplasan. Metode penelitian ini bersifat explanatory dengan menggunakan pendekatan belah lintang. Populasi dalam penelitian ini adalah pekerja bagian pengamplasan sebanyak 30 orang. Teknik ...

  19. Power Reactor Docket Information. Annual cumulation (citations)

    International Nuclear Information System (INIS)

    1977-12-01

    An annual cumulation of the citations to the documentation associated with civilian nuclear power plants is presented. This material is that which is submitted to the U.S. Nuclear Regulatory Commission in support of applications for construction and operating licenses. Citations are listed by Docket number in accession number sequence. The Table of Contents is arranged both by Docket number and by nuclear power plant name

  20. Cumulative Effect of Depression on Dementia Risk

    OpenAIRE

    Olazarán, J.; Trincado, R.; Bermejo-Pareja, F.

    2013-01-01

    Objective. To analyze a potential cumulative effect of life-time depression on dementia and Alzheimer's disease (AD), with control of vascular factors (VFs). Methods. This study was a subanalysis of the Neurological Disorders in Central Spain (NEDICES) study. Past and present depression, VFs, dementia status, and dementia due to AD were documented at study inception. Dementia status was also documented after three years. Four groups were created according to baseline data: never depression (n...

  1. Cumulative release to the accessible environment

    International Nuclear Information System (INIS)

    Kanehiro, B.

    1985-01-01

    The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Fractional Release Subgroup are presented

  2. Segmentation of 3-D High-Frequency Ultrasound Images of Human Lymph Nodes Using Graph Cut With Energy Functional Adapted to Local Intensity Distribution.

    Science.gov (United States)

    Kuo, Jen-Wei; Mamou, Jonathan; Wang, Yao; Saegusa-Beecroft, Emi; Machi, Junji; Feleppa, Ernest J

    2017-10-01

    Previous studies by our group have shown that 3-D high-frequency quantitative ultrasound (QUS) methods have the potential to differentiate metastatic lymph nodes (LNs) from cancer-free LNs dissected from human cancer patients. To successfully perform these methods inside the LN parenchyma (LNP), an automatic segmentation method is highly desired to exclude the surrounding thin layer of fat from QUS processing and accurately correct for ultrasound attenuation. In high-frequency ultrasound images of LNs, the intensity distribution of LNP and fat varies spatially because of acoustic attenuation and focusing effects. Thus, the intensity contrast between two object regions (e.g., LNP and fat) is also spatially varying. In our previous work, nested graph cut (GC) demonstrated its ability to simultaneously segment LNP, fat, and the outer phosphate-buffered saline bath even when some boundaries are lost because of acoustic attenuation and focusing effects. This paper describes a novel approach called GC with locally adaptive energy to further deal with spatially varying distributions of LNP and fat caused by inhomogeneous acoustic attenuation. The proposed method achieved Dice similarity coefficients of 0.937±0.035 when compared with expert manual segmentation on a representative data set consisting of 115 3-D LN images obtained from colorectal cancer patients.

  3. EPA Workshop on Epigenetics and Cumulative Risk ...

    Science.gov (United States)

    Agenda Download the Workshop Agenda (PDF) The workshop included presentations and discussions by scientific experts pertaining to three topics (i.e., epigenetic changes associated with diverse stressors, key science considerations in understanding epigenetic changes, and practical application of epigenetic tools to address cumulative risks from environmental stressors), to address several questions under each topic, and included an opportunity for attendees to participate in break-out groups, provide comments and ask questions. Workshop Goals The workshop seeks to examine the opportunity for use of aggregate epigenetic change as an indicator in cumulative risk assessment for populations exposed to multiple stressors that affect epigenetic status. Epigenetic changes are specific molecular changes around DNA that alter expression of genes. Epigenetic changes include DNA methylation, formation of histone adducts, and changes in micro RNAs. Research today indicates that epigenetic changes are involved in many chronic diseases (cancer, cardiovascular disease, obesity, diabetes, mental health disorders, and asthma). Research has also linked a wide range of stressors including pollution and social factors with occurrence of epigenetic alterations. Epigenetic changes have the potential to reflect impacts of risk factors across multiple stages of life. Only recently receiving attention is the nexus between the factors of cumulative exposure to environmental

  4. Higher order cumulants in colorless partonic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S. [Sciences and Technologies Department, University of Ghardaia, Ghardaia, Algiers (Algeria); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ahmed, M. A. A. [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Department of Physics, Taiz University in Turba, Taiz (Yemen); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ladrem, M., E-mail: mladrem@yahoo.fr [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria)

    2016-06-10

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.

  5. Cumulative irritation potential of topical retinoid formulations.

    Science.gov (United States)

    Leyden, James J; Grossman, Rachel; Nighland, Marge

    2008-08-01

    Localized irritation can limit treatment success with topical retinoids such as tretinoin and adapalene. The factors that influence irritant reactions have been shown to include individual skin sensitivity, the particular retinoid and concentration used, and the vehicle formulation. To compare the cutaneous tolerability of tretinoin 0.04% microsphere gel (TMG) with that of adapalene 0.3% gel and a standard tretinoin 0.025% cream. The results of 2 randomized, investigator-blinded studies of 2 to 3 weeks' duration, which utilized a split-face method to compare cumulative irritation scores induced by topical retinoids in subjects with healthy skin, were combined. Study 1 compared TMG 0.04% with adapalene 0.3% gel over 2 weeks, while study 2 compared TMG 0.04% with tretinoin 0.025% cream over 3 weeks. In study 1, TMG 0.04% was associated with significantly lower cumulative scores for erythema, dryness, and burning/stinging than adapalene 0.3% gel. However, in study 2, there were no significant differences in cumulative irritation scores between TMG 0.04% and tretinoin 0.025% cream. Measurements of erythema by a chromameter showed no significant differences between the test formulations in either study. Cutaneous tolerance of TMG 0.04% on the face was superior to that of adapalene 0.3% gel and similar to that of a standard tretinoin cream containing a lower concentration of the drug (0.025%).

  6. A cumulative analysis of odontogenic cysts from major dental institutions of Bangalore city: A study of 252 cases.

    Science.gov (United States)

    Ramachandra, Prashanth; Maligi, Prathima; Raghuveer, Hp

    2011-01-01

    The objective of this study was to perform a cumulative analysis of odontogenic cysts obtained from the data of major dental institutions of Bangalore city, as well as to evaluate their distribution during a 5-year period and compare the results with other international studies. Data for the study were obtained from the reports of patients diagnosed with odontogenic cysts between 2005 and 2010 from different dental institutions of Bangalore. Case records of patients that fit the histological classification of the World Health Organization (WHO) (2005) were included in the study and the following variables were analyzed: age, gender, anatomic location, and histological type. In a total of 252 cyst specimens diagnosed, 79.76% were odontogenic cysts and 20.24% were nonodontogenic cysts. Among the odontogenic cysts most frequent lesions were radicular cysts (50.25%), followed by keratocysts (27.36%) and dentigerous cysts (22.39%). Our study provides a cumulative data of odontogenic cysts in the population of Bangalore city. The results of our study showed a similar frequency of odontogenic cysts as compared to other populations of the world, with radicular cyst being identified as the most frequent odontogenic cyst. Keratocyst was the second most common cyst followed by dentigerous cyst.

  7. Frequency and distribution of 152 genetic disease variants in over 100,000 mixed breed and purebred dogs.

    Directory of Open Access Journals (Sweden)

    Jonas Donner

    2018-04-01

    Full Text Available Knowledge on the genetic epidemiology of disorders in the dog population has implications for both veterinary medicine and sustainable breeding. Limited data on frequencies of genetic disease variants across breeds exists, and the disease heritage of mixed breed dogs remains poorly explored to date. Advances in genetic screening technologies now enable comprehensive investigations of the canine disease heritage, and generate health-related big data that can be turned into action. We pursued population screening of genetic variants implicated in Mendelian disorders in the largest canine study sample examined to date by examining over 83,000 mixed breed and 18,000 purebred dogs representing 330 breeds for 152 known variants using a custom-designed beadchip microarray. We further announce the creation of MyBreedData (www.mybreeddata.com, an online updated inherited disorder prevalence resource with its foundation in the generated data. We identified the most prevalent, and rare, disease susceptibility variants across the general dog population while providing the first extensive snapshot of the mixed breed disease heritage. Approximately two in five dogs carried at least one copy of a tested disease variant. Most disease variants are shared by both mixed breeds and purebreds, while breed- or line-specificity of others is strongly suggested. Mixed breed dogs were more likely to carry a common recessive disease, whereas purebreds were more likely to be genetically affected with one, providing DNA-based evidence for hybrid vigor. We discovered genetic presence of 22 disease variants in at least one additional breed in which they were previously undescribed. Some mutations likely manifest similarly independently of breed background; however, we emphasize the need for follow up investigations in each case and provide a suggested validation protocol for broader consideration. In conclusion, our study provides unique insight into genetic epidemiology of

  8. Distribution Frequency and Incidence of Seed-borne Pathogens of Some Cereals and Industrial Crops in Serbia

    Directory of Open Access Journals (Sweden)

    Jelena Lević

    2012-01-01

    Full Text Available A total of 41 species of fungi were isolated from seed samples of barley, maize, soybean,and sunflower collected at different locations in Serbia. The majority of detected speciesoccurred on barley (35 of 41 species or 87.8% comparing to soybean (17 of 41 species or41.5%, sunflower (16 of 41 species or 39.0% and maize (15 of 41 species or 36.9%. Speciesbelonging to genera Alternaria, Chaetomium, Epicoccum, Fusarium, Penicillium and Rhizopuswere present on seeds of all four plant species. Alternaria species were dominant on soybean,barley and sunflower seeds (85.7%, 84.7% and 76.9%. F. verticillioides and Penicilliumspp. were mainly isolated from maize seeds (100 and 92.3% respectively, while other specieswere isolated up to 38.5% (Chaetomium spp. and Rhizopus spp.. F. graminearum, F. proliferatum,F. poae and F. sporotrichioides were the most common Fusarium species isolatedfrom barley (51.1-93.3%, while on the soybean seeds F. oxysporum (71.4%, F. semitectum(57.1% and F. sporotrichioides (57.1% were prevalent. Frequency of Fusarium species onsunflower seeds varied from 7% (F. equiseti, F. graminearum, F. proliferatum and F. subglutinansto 15.4% (F. verticillioides. Statistically significant negative correlation (r = –0.678* wasdetermined for the incidence of F. graminearum and Alternaria spp., as well as, Fusarium spp.and Alternaria spp. (r = –0.614*, on barley seeds. The obtained results revealed that seedbornepathogens were present in most seed samples of important cereals and industrialcrops grown under different agroecological conditions in Serbia. Some of the identifiedfungi are potential producers of mycotoxins, thus their presence is important in termsof reduced food safety for humans and animals. Therefore, an early and accurate diagnosisand pathogen surveillance will provide time for the development and the applicationof disease strategies.

  9. Degree distribution in discrete case

    International Nuclear Information System (INIS)

    Wang, Li-Na; Chen, Bin; Yan, Zai-Zai

    2011-01-01

    Vertex degree of many network models and real-life networks is limited to non-negative integer. By means of measure and integral, the relation of the degree distribution and the cumulative degree distribution in discrete case is analyzed. The degree distribution, obtained by the differential of its cumulative, is only suitable for continuous case or discrete case with constant degree change. When degree change is not a constant but proportional to degree itself, power-law degree distribution and its cumulative have the same exponent and the mean value is finite for power-law exponent greater than 1. -- Highlights: → Degree change is the crux for using the cumulative degree distribution method. → It suits for discrete case with constant degree change. → If degree change is proportional to degree, power-law degree distribution and its cumulative have the same exponent. → In addition, the mean value is finite for power-law exponent greater than 1.

  10. Frequency and distribution of forest, savanna, and crop fires over tropical regions during PEM-Tropics A

    Science.gov (United States)

    Olson, Jennifer R.; Baum, Bryan A.; Cahoon, Donald R.; Crawford, James H.

    1999-03-01

    Advanced very high resolution radiometer 1.1 km resolution satellite radiance data were used to locate active fires throughout much of the tropical region during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics (PEM-Tropics A) aircraft campaign, held in September and October 1996. The spatial and temporal distributions of the fires in Australia, southern Africa, and South America are presented here. The number of fires over northern Australia, central Africa, and South America appeared to decrease toward the end of the mission period. Fire over eastern Australia was widespread, and temporal patterns showed a somewhat consistent amount of burning with periodic episodes of enhanced fire counts observed. At least one episode of enhanced fire counts corresponded to the passage of a frontal system which brought conditions conducive to fire to the region, with strong westerlies originating over the hot, dry interior continent. Regions that were affected by lower than normal rainfall during the previous wet season (e.g., northern Australia and southwestern Africa) showed relatively few fires during this period. This is consistent with a drought-induced decrease in vegetation and therefore a decreased availability of fuel for burning. Alternatively, a heavier than normal previous wet season along the southeastern coast of South Africa may have contributed to high fuel loading and an associated relatively heavy amount of burning compared to data from previous years.

  11. Cumulative keyboard strokes: a possible risk factor for carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    Eleftheriou Andreas

    2012-08-01

    Full Text Available Abstract Background Contradictory reports have been published regarding the association of Carpal Tunnel Syndrome (CTS and the use of computer keyboard. Previous studies did not take into account the cumulative exposure to keyboard strokes among computer workers. The aim of the present study was to investigate the association between cumulative keyboard use (keyboard strokes and CTS. Methods Employees (461 from a Governmental data entry & processing unit agreed to participate (response rate: 84.1 % in a cross-sectional study. Α questionnaire was distributed to the participants to obtain information on socio-demographics and risk factors for CTS. The participants were examined for signs and symptoms related to CTS and were asked if they had previous history or surgery for CTS. The cumulative amount of the keyboard strokes per worker per year was calculated by the use of payroll’s registry. Two case definitions for CTS were used. The first included subjects with personal history/surgery for CTS while the second included subjects that belonged to the first case definition plus those participants were identified through clinical examination. Results Multivariate analysis used for both case definitions, indicated that those employees with high cumulative exposure to keyboard strokes were at increased risk of CTS (case definition A: OR = 2.23;95 % CI = 1.09-4.52 and case definition B: OR = 2.41; 95%CI = 1.36-4.25. A dose response pattern between cumulative exposure to keyboard strokes and CTS has been revealed (p  Conclusions The present study indicated a possible association between cumulative exposure to keyboard strokes and development of CTS. Cumulative exposure to key-board strokes would be taken into account as an exposure indicator regarding exposure assessment of computer workers. Further research is needed in order to test the results of the current study and assess causality between cumulative keyboard strokes and

  12. Impact of soil-structure interaction on the probabilistic frequency variation of concrete structures

    International Nuclear Information System (INIS)

    Hadjian, A.H.; Hamilton, C.W.

    1975-01-01

    Earthquake response of equipment in nuclear power plants is characterized by floor response spectra. Since these spectra peak at the natural frequencies of the structure, it is important, both from safety and cost standpoints, to determine the degree of the expected variability of the calculated structural frequencies. A previous work is extended on the variability of the natural frequencies of structures due to the variations of concrete properties and a rigorous approach is presented to evaluate frequency variations based on the probability distributions of both the structural and soil parameters and jointly determine the distributions of the natural frequencies. It is assumed that the soil-structure interaction coefficients are normally distributed. With the proper choice of coordinates, the simultaneous random variations of both the structural properties and the interaction coefficients can be incorporated in the eigenvalue problem. The key methodology problem is to obtain the probability distribution of eigenvalues of matrices with random variable elements. Since no analytic relation exists between the eigenvalues and the elements, a numerical procedure had to be designed. It was found that the desired accuracy can be best achieved by splitting the joint variation into two parts: the marginal distribution of soil variations and the conditional distribution of structural variations at specific soil fractiles. Then after calculating the actual eigenvalues at judiciously selected paired values of soil and structure parameters, this information is recombined to obtain the desired cumulative distribution of natural frequencies

  13. A bivariate optimal replacement policy with cumulative repair cost ...

    Indian Academy of Sciences (India)

    Min-Tsai Lai

    Shock model; cumulative damage model; cumulative repair cost limit; preventive maintenance model. 1. Introduction ... with two types of shocks: one type is failure shock, and the other type is damage ...... Theory, methods and applications.

  14. Boundary curves of individual items in the distribution of total depressive symptom scores approximate an exponential pattern in a general population

    OpenAIRE

    Tomitaka, Shinichiro; Kawasaki, Yohei; Ide, Kazuki; Akutagawa, Maiko; Yamada, Hiroshi; Furukawa, Toshiaki A.; Ono, Yutaka

    2016-01-01

    [Background]Previously, we proposed a model for ordinal scale scoring in which individual thresholds for each item constitute a distribution by each item. This lead us to hypothesize that the boundary curves of each depressive symptom score in the distribution of total depressive symptom scores follow a common mathematical model, which is expressed as the product of the frequency of the total depressive symptom scores and the probability of the cumulative distribution function of each item th...

  15. On interference of cumulative proton production mechanisms

    International Nuclear Information System (INIS)

    Braun, M.A.; Vechernin, V.V.

    1993-01-01

    The dynamical picture of the cumulative proton production in hA-collisions by means of diagram analysis with NN interaction described by a non-relativistic NN potential is considered. The contributions of the various mechanisms (spectator, direct and rescattering) for backward hemisphere proton production within the framework of this common approach is calculated. The emphasis is on the comparison of the relative contributions of these mechanisms for various angles, taking into account the interference of these contributions. Comparison with experimental data is also presented. (author)

  16. Preserved cumulative semantic interference despite amnesia

    Directory of Open Access Journals (Sweden)

    Gary Michael Oppenheim

    2015-05-01

    As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

  17. Is cumulated pyrethroid exposure associated with prediabetes?

    DEFF Research Database (Denmark)

    Hansen, Martin Rune; Jørs, Erik; Lander, Flemming

    2014-01-01

    was to investigate an association between exposure to pyrethroids and abnormal glucose regulation (prediabetes or diabetes). A cross-sectional study was performed among 116 pesticide sprayers from public vector control programs in Bolivia and 92 nonexposed controls. Pesticide exposure (duration, intensity...... pyrethroids, a significant positive trend was observed between cumulative pesticide exposure (total number of hours sprayed) and adjusted OR of abnormal glucose regulation, with OR 14.7 [0.9-235] in the third exposure quintile. The study found a severely increased prevalence of prediabetes among Bolivian...

  18. Universal global imprints of genome growth and evolution--equivalent length and cumulative mutation density.

    Directory of Open Access Journals (Sweden)

    Hong-Da Chen

    Full Text Available BACKGROUND: Segmental duplication is widely held to be an important mode of genome growth and evolution. Yet how this would affect the global structure of genomes has been little discussed. METHODS/PRINCIPAL FINDINGS: Here, we show that equivalent length, or L(e, a quantity determined by the variance of fluctuating part of the distribution of the k-mer frequencies in a genome, characterizes the latter's global structure. We computed the L(es of 865 complete chromosomes and found that they have nearly universal but (k-dependent values. The differences among the L(e of a chromosome and those of its coding and non-coding parts were found to be slight. CONCLUSIONS: We verified that these non-trivial results are natural consequences of a genome growth model characterized by random segmental duplication and random point mutation, but not of any model whose dominant growth mechanism is not segmental duplication. Our study also indicates that genomes have a nearly universal cumulative "point" mutation density of about 0.73 mutations per site that is compatible with the relatively low mutation rates of (1-5 x 10(-3/site/Mya previously determined by sequence comparison for the human and E. coli genomes.

  19. Somatic involvement assessed through a cumulative score of clinical severity in patients with eating disorders.

    Science.gov (United States)

    Scanelli, Giovanni; Gualandi, Malvina; Simoni, Marzia; Manzato, Emilia

    2014-03-01

    To evaluate the overall somatic involvement in patients with eating disorders (EDs). The medical records of 206 patients (age 15-56 years, 96.1% females) with diagnosis of anorexia nervosa (AN, n = 63, 30.6%), bulimia nervosa (BN, n = 78, 37.9%), or eating disorder not otherwise specified (EDNOS, n = 65, 31.6 %) were analyzed. A cumulative score of clinical severity (SCS) was computed according to the presence of physical, instrumental, and laboratory abnormalities, as well as to their prognostic impact. Based on the tertile distribution of SCS, three levels of severity were defined: low, medium, and high. A medium/high level of severity was found in 63% of the whole sample, 89% of AN, 49% of BN, and 55% of EDNOS. In the whole sample, the risk of medium/high SCS was significantly and inversely related to the body mass index (BMI) and to the lifetime minimum BMI. The severity level was significantly and positively associated with diagnosis of AN, duration of amenorrhea C1 year, and presence of ED-related symptoms. EDNOS patients showed a higher risk for increased SCS than BN patients, although not significantly. The non-negligible frequency of a relevant somatic involvement in patients with EDNOS suggests that a transdiagnostic scoring system might be helpful to identify ED cases at risk of medical complications.

  20. Personal measures of power-frequency magnetic field exposure among men from an infertility clinic: distribution, temporal variability and correlation with their female partners' exposure

    International Nuclear Information System (INIS)

    Lewis, Ryan C.; Hauser, Russ; Maynard, Andrew D.; Neitzel, Richard L.; Meeker, John D.; Wang, Lu; Kavet, Robert; Morey, Patricia; Ford, Jennifer B.

    2016-01-01

    Power-frequency magnetic field exposure science as it relates to men and couples have not been explored despite the advantage of this information in the design and interpretation of reproductive health epidemiology studies. This analysis examined the distribution and temporal variability of exposures in men, and the correlation of exposures within couples using data from a longitudinal study of 25 men and their female partners recruited from an infertility clinic. The average and 90. percentile demonstrated fair to good reproducibility, whereas the maximum showed poor reproducibility over repeated sampling days, each separated by a median of 4.6 weeks. Average magnetic field exposures were also strongly correlated within couples, suggesting that one partner's data could be used as a surrogate in the absence of data from the other for this metric. Environment was also an important effect modifier in these explored matters. These issues should be considered in future relevant epidemiology studies. (authors)

  1. Conceptual citation frequency - quantum mechanics and elementary particle physics

    International Nuclear Information System (INIS)

    Hurt, C.D.

    1986-01-01

    The differences in conceptual citation frequency are examined between quantum mechanics literature and elementary particle physics literature. Using a sample based on increments of 5 years, 7 contrast tests were generated over a literature period of 35 years. A Dunn planned comparison procedure indicated a statistical difference in years 5 and 10 but no differences were found in the remaining years. The results must be weighed against the time frames in which the literature was produced but clearly point to an initial difference in the two areas. Additional work is required to reevaluate the findings and to investigate the conceptual citation frequency issue further. The frequency distribution generated approximates a cumulative advantage process. (author)

  2. Chapter 19. Cumulative watershed effects and watershed analysis

    Science.gov (United States)

    Leslie M. Reid

    1998-01-01

    Cumulative watershed effects are environmental changes that are affected by more than.one land-use activity and that are influenced by.processes involving the generation or transport.of water. Almost all environmental changes are.cumulative effects, and almost all land-use.activities contribute to cumulative effects

  3. Original and cumulative prospect theory: a discussion of empirical differences

    NARCIS (Netherlands)

    Wakker, P.P.; Fennema, H.

    1997-01-01

    This note discusses differences between prospect theory and cumulative prospect theory. It shows that cumulative prospect theory is not merely a formal correction of some theoretical problems in prospect theory, but it also gives different predictions. Experiments are described that favor cumulative

  4. Effect of cumulative strain on texture characteristics during wire drawing of eutectoid steels

    International Nuclear Information System (INIS)

    Yang, F.; Ma, C.; Jiang, J.Q.; Feng, H.P.; Zhai, S.Y.

    2008-01-01

    The texture characteristics associated with plastic deformation of Fe-C steels near-eutectoid composition during a continuous cold drawing process were thoroughly investigated by orientation distribution function analysis based on X-ray diffraction. The effect of cumulative drawing strains on the fiber texture in drawn hypereutectoid and hypoeutectoid steel wires was discussed

  5. A probabilistic analysis of cumulative carbon emissions and long-term planetary warming

    International Nuclear Information System (INIS)

    Fyke, Jeremy; Matthews, H Damon

    2015-01-01

    Efforts to mitigate and adapt to long-term climate change could benefit greatly from probabilistic estimates of cumulative carbon emissions due to fossil fuel burning and resulting CO 2 -induced planetary warming. Here we demonstrate the use of a reduced-form model to project these variables. We performed simulations using a large-ensemble framework with parametric uncertainty sampled to produce distributions of future cumulative emissions and consequent planetary warming. A hind-cast ensemble of simulations captured 1980–2012 historical CO 2 emissions trends and an ensemble of future projection simulations generated a distribution of emission scenarios that qualitatively resembled the suite of Representative and Extended Concentration Pathways. The resulting cumulative carbon emission and temperature change distributions are characterized by 5–95th percentile ranges of 0.96–4.9 teratonnes C (Tt C) and 1.4 °C–8.5 °C, respectively, with 50th percentiles at 3.1 Tt C and 4.7 °C. Within the wide range of policy-related parameter combinations that produced these distributions, we found that low-emission simulations were characterized by both high carbon prices and low costs of non-fossil fuel energy sources, suggesting the importance of these two policy levers in particular for avoiding dangerous levels of climate warming. With this analysis we demonstrate a probabilistic approach to the challenge of identifying strategies for limiting cumulative carbon emissions and assessing likelihoods of surpassing dangerous temperature thresholds. (letter)

  6. Warfarin maintenance dose in older patients: higher average dose and wider dose frequency distribution in patients of African ancestry than those of European ancestry.

    Science.gov (United States)

    Garwood, Candice L; Clemente, Jennifer L; Ibe, George N; Kandula, Vijay A; Curtis, Kristy D; Whittaker, Peter

    2010-06-15

    Studies report that warfarin doses required to maintain therapeutic anticoagulation decrease with age; however, these studies almost exclusively enrolled patients of European ancestry. Consequently, universal application of dosing paradigms based on such evidence may be confounded because ethnicity also influences dose. Therefore, we determined if warfarin dose decreased with age in Americans of African ancestry, if older African and European ancestry patients required different doses, and if their daily dose frequency distributions differed. Our chart review examined 170 patients of African ancestry and 49 patients of European ancestry cared for in our anticoagulation clinic. We calculated the average weekly dose required for each stable, anticoagulated patient to maintain an international normalized ratio of 2.0 to 3.0, determined dose averages for groups 80 years of age and plotted dose as a function of age. The maintenance dose in patients of African ancestry decreased with age (PAfrican ancestry required higher average weekly doses than patients of European ancestry: 33% higher in the 70- to 79-year-old group (38.2+/-1.9 vs. 28.8+/-1.7 mg; P=0.006) and 52% in the >80-year-old group (33.2+/-1.7 vs. 21.8+/-3.8 mg; P=0.011). Therefore, 43% of older patients of African ancestry required daily doses >5mg and hence would have been under-dosed using current starting-dose guidelines. The dose frequency distribution was wider for older patients of African ancestry compared to those of European ancestry (PAfrican ancestry indicate that strategies for initiating warfarin therapy based on studies of patients of European ancestry could result in insufficient anticoagulation and thereby potentially increase their thromboembolism risk. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Efficient generation of 1.9  W yellow light by cascaded frequency doubling of a distributed Bragg reflector tapered diode

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Christensen, Mathias; Noordegraaf, Danny

    2016-01-01

    Watt-level yellow emitting lasers are interesting for medical applications, due to their high hemoglobin absorption, and for efficient detection of certain fluorophores. In this paper, we demonstrate a compact and robust diode-based laser system in the yellow spectral range. The system generates ...... of a laser diode enables the modulation of the pump wavelength by controlling the drive current. This is utilized to achieve a power modulation depth above 90% for the second harmonic light, with a rise time below 40  μs.......Watt-level yellow emitting lasers are interesting for medical applications, due to their high hemoglobin absorption, and for efficient detection of certain fluorophores. In this paper, we demonstrate a compact and robust diode-based laser system in the yellow spectral range. The system generates 1.......9 W of single-frequency light at 562.4 nm by cascaded single-pass frequency doubling of the 1124.8 nm emission from a distributed Bragg reflector (DBR) tapered laser diode. The absence of a free-space cavity makes the system stable over a base-plate temperature range of 30 K. At the same time, the use...

  8. A Multi-Band Body-Worn Distributed Radio-Frequency Exposure Meter: Design, On-Body Calibration and Study of Body Morphology

    Science.gov (United States)

    Thielens, Arno; Agneessens, Sam; Van Torre, Patrick; Van den Bossche, Matthias; Eeftens, Marloes; Huss, Anke; Vermeulen, Roel; de Seze, René; Mazet, Paul; Cardis, Elisabeth; Röösli, Martin; Martens, Luc; Joseph, Wout

    2018-01-01

    A multi-band Body-Worn Distributed exposure Meter (BWDM) calibrated for simultaneous measurement of the incident power density in 11 telecommunication frequency bands, is proposed. The BDWM consists of 22 textile antennas integrated in a garment and is calibrated on six human subjects in an anechoic chamber to assess its measurement uncertainty in terms of 68% confidence interval of the on-body antenna aperture. It is shown that by using multiple antennas in each frequency band, the uncertainty of the BWDM is 22 dB improved with respect to single nodes on the front and back of the torso and variations are decreased to maximum 8.8 dB. Moreover, deploying single antennas for different body morphologies results in a variation up to 9.3 dB, which is reduced to 3.6 dB using multiple antennas for six subjects with various body mass index values. The designed BWDM, has an improved uncertainty of up to 9.6 dB in comparison to commercially available personal exposure meters calibrated on body. As an application, an average incident power density in the range of 26.7–90.8 μW·m−2 is measured in Ghent, Belgium. The measurements show that commercial personal exposure meters underestimate the actual exposure by a factor of up to 20.6. PMID:29346280

  9. A Multi-Band Body-Worn Distributed Radio-Frequency Exposure Meter: Design, On-Body Calibration and Study of Body Morphology

    Directory of Open Access Journals (Sweden)

    Reza Aminzadeh

    2018-01-01

    Full Text Available A multi-band Body-Worn Distributed exposure Meter (BWDM calibrated for simultaneous measurement of the incident power density in 11 telecommunication frequency bands, is proposed. The BDWM consists of 22 textile antennas integrated in a garment and is calibrated on six human subjects in an anechoic chamber to assess its measurement uncertainty in terms of 68% confidence interval of the on-body antenna aperture. It is shown that by using multiple antennas in each frequency band, the uncertainty of the BWDM is 22 dB improved with respect to single nodes on the front and back of the torso and variations are decreased to maximum 8.8 dB. Moreover, deploying single antennas for different body morphologies results in a variation up to 9.3 dB, which is reduced to 3.6 dB using multiple antennas for six subjects with various body mass index values. The designed BWDM, has an improved uncertainty of up to 9.6 dB in comparison to commercially available personal exposure meters calibrated on body. As an application, an average incident power density in the range of 26.7–90.8 μW·m − 2 is measured in Ghent, Belgium. The measurements show that commercial personal exposure meters underestimate the actual exposure by a factor of up to 20.6.

  10. Use of high-frequency ultrasonography for evaluation of skin thickness in relation to hydration status and fluid distribution at various cutaneous sites in dogs.

    Science.gov (United States)

    Diana, Alessia; Guglielmini, Carlo; Fracassi, Federico; Pietra, Marco; Balletti, Erika; Cipone, Mario

    2008-09-01

    To assess the usefulness of high-frequency diagnostic ultrasonography for evaluation of changes of skin thickness in relation to hydration status and fluid distribution at various cutaneous sites in dogs. 10 clinically normal adult dogs (6 males and 4 females) of various breeds. Ultrasonographic examination of the skin was performed before and after hydration via IV administration of an isotonic crystalloid solution (30 mL/kg/h for 30 minutes). A 13-MHz linear-array transducer was used to obtain series of ultrasonographic images at 4 different cutaneous sites (the frontal, sacral, flank, and metatarsal regions). Weight and various clinicopathologic variables (PCV; serum osmolality; and serum total protein, albumin, and sodium concentrations) were determined before and after the infusion. These variables and ultrasonographic measurements of skin thickness before and after hydration were compared. Among the 10 dogs, mean preinfusion skin thickness ranged from 2,211 microm (metatarsal region) to 3,249 microm (sacral region). Compared with preinfusion values, weight was significantly increased, whereas PCV; serum osmolality; and serum total protein, albumin, and sodium concentrations were significantly decreased after infusion. After infusion, dermal echogenicity decreased and skin thickness increased significantly by 21%, 14%, 15%, and 13% in the frontal, sacral, flank, and metatarsal regions, respectively. Cutaneous site and hydration were correlated with cutaneous characteristics and skin thickness determined by use of high-frequency ultrasonography in dogs. Thus, diagnostic ultrasonography may be a useful tool for the noninvasive evaluation of skin hydration in healthy dogs and in dogs with skin edema.

  11. Cumulative Environmental Management Association : Wood Buffalo Region

    International Nuclear Information System (INIS)

    Friesen, B.

    2001-01-01

    The recently announced oil sands development of the Wood Buffalo Region in Alberta was the focus of this power point presentation. Both mining and in situ development is expected to total $26 billion and 2.6 million barrels per day of bitumen production. This paper described the economic, social and environmental challenges facing the resource development of this region. In addition to the proposed oil sands projects, this region will accommodate the needs of conventional oil and gas production, forestry, building of pipelines and power lines, municipal development, recreation, tourism, mining exploration and open cast mining. The Cumulative Environmental Management Association (CEMA) was inaugurated as a non-profit association in April 2000, and includes 41 members from all sectors. Its major role is to ensure a sustainable ecosystem and to avoid any cumulative impacts on wildlife. Other work underway includes the study of soil and plant species diversity, and the effects of air emissions on human health, wildlife and vegetation. The bioaccumulation of heavy metals and their impacts on surface water and fish is also under consideration to ensure the quality and quantity of surface water and ground water. 3 figs

  12. Optimal execution with price impact under Cumulative Prospect Theory

    Science.gov (United States)

    Zhao, Jingdong; Zhu, Hongliang; Li, Xindan

    2018-01-01

    Optimal execution of a stock (or portfolio) has been widely studied in academia and in practice over the past decade, and minimizing transaction costs is a critical point. However, few researchers consider the psychological factors for the traders. What are traders truly concerned with - buying low in the paper accounts or buying lower compared to others? We consider the optimal trading strategies in terms of the price impact and Cumulative Prospect Theory and identify some specific properties. Our analyses indicate that a large proportion of the execution volume is distributed at both ends of the transaction time. But the trader's optimal strategies may not be implemented at the same transaction size and speed in different market environments.

  13. Cumulative effective and individual organ dose levels in paediatric patients undergoing multiple catheterizations for congenital heart disease

    International Nuclear Information System (INIS)

    Jones, T.P.; Brennan, P.C.; Ryan, E.

    2017-01-01

    This study examines the cumulative radiation dose levels received by a group of children who underwent multiple cardiac catheterisation procedures during the investigation and management of congenital heart disease (CHD). The purpose is to calculate cumulative doses, identify higher dose individuals, outline the inconsistencies with risk assessment and encourage the establishment of dose databases in order to facilitate the longitudinal research necessary to better understand health risks. A retrospective review of patient records for 117 paediatric patients who have undergone two or more cardiac catheterizations for the investigation of CHD was undertaken. This cohort consisted of patients who were catheterised over a period from September 2002 to August 2014. The age distribution was from newborn to 17 y. Archived kerma-area product (P KA ) and fluoroscopy time (T) readings were retrieved and analysed. Cumulative effective and individual organ doses were determined. The cumulative P KA levels ranged from 1.8 to 651.2 Gycm 2 , whilst cumulative effective dose levels varied from 2 to 259 mSv. The cumulative fluoroscopy time was shown to vary from 8.1 to 193.5 min. Median cumulative organ doses ranged from 3 to 94 mGy. Cumulative effective dose levels are highly variable but may exceed 250 mSv. Individual organ and effective dose measurements remain useful for comparison purposes between institutions although current methodologies used for determining lifetime risks are inadequate. (authors)

  14. Frequency distribution of specific activities and radiological hazard assessment in surface beach sand samples collected in Bangsaen beach in Chonburi province, Thailand

    Science.gov (United States)

    Changkit, N.; Boonkrongcheep, R.; Youngchauy, U.; Polthum, S.; Kessaratikoon, P.

    2017-09-01

    The specific activities of natural radionuclides (40K, 226Ra and 232Th) in 50 surface beach sand samples collected from Bangsaen beach in Chonburi province in the easthern region of Thailand, were measured and evaluated. Experimental results were obtained by using a high-purity germanium (HPGe) detector and gamma spectrometry analysis system in the special laboratory at Thailand Institute of Nuclear Technology (Public Organization). The IAEA-SOIL-375 reference material was used to analyze the concentration of 40K, 226Ra and 232Th in all samples. It was found that the specific activities of 40K, 226Ra and 232Th were ranged from 510.85 - 771.35, 8.17 - 17.06 and 4.25 - 15.68 Bq/kg. Furthermore, frequency distribution of the specific activities were studied, analyzed and found to be the asymmetrical distribution by using a statistical computer program. Moreover, four radiological hazard indices for the investigated area were also calculated by using the median values of specific activities of 40K, 226Ra and 232Th. The results were also compared with the Office of Atoms for Peace (OAP) annual report data, Thailand and global radioactivity measurement and evaluations.

  15. Spatially variable stage-driven groundwater-surface water interaction inferred from time-frequency analysis of distributed temperature sensing data

    Science.gov (United States)

    Mwakanyamale, Kisa; Slater, Lee; Day-Lewis, Frederick D.; Elwaseif, Mehrez; Johnson, Carole D.

    2012-01-01

    Characterization of groundwater-surface water exchange is essential for improving understanding of contaminant transport between aquifers and rivers. Fiber-optic distributed temperature sensing (FODTS) provides rich spatiotemporal datasets for quantitative and qualitative analysis of groundwater-surface water exchange. We demonstrate how time-frequency analysis of FODTS and synchronous river stage time series from the Columbia River adjacent to the Hanford 300-Area, Richland, Washington, provides spatial information on the strength of stage-driven exchange of uranium contaminated groundwater in response to subsurface heterogeneity. Although used in previous studies, the stage-temperature correlation coefficient proved an unreliable indicator of the stage-driven forcing on groundwater discharge in the presence of other factors influencing river water temperature. In contrast, S-transform analysis of the stage and FODTS data definitively identifies the spatial distribution of discharge zones and provided information on the dominant forcing periods (≥2 d) of the complex dam operations driving stage fluctuations and hence groundwater-surface water exchange at the 300-Area.

  16. Quadratic Frequency Modulation Signals Parameter Estimation Based on Two-Dimensional Product Modified Parameterized Chirp Rate-Quadratic Chirp Rate Distribution.

    Science.gov (United States)

    Qu, Zhiyu; Qu, Fuxin; Hou, Changbo; Jing, Fulong

    2018-05-19

    In an inverse synthetic aperture radar (ISAR) imaging system for targets with complex motion, the azimuth echo signals of the target are always modeled as multicomponent quadratic frequency modulation (QFM) signals. The chirp rate (CR) and quadratic chirp rate (QCR) estimation of QFM signals is very important to solve the ISAR image defocus problem. For multicomponent QFM (multi-QFM) signals, the conventional QR and QCR estimation algorithms suffer from the cross-term and poor anti-noise ability. This paper proposes a novel estimation algorithm called a two-dimensional product modified parameterized chirp rate-quadratic chirp rate distribution (2D-PMPCRD) for QFM signals parameter estimation. The 2D-PMPCRD employs a multi-scale parametric symmetric self-correlation function and modified nonuniform fast Fourier transform-Fast Fourier transform to transform the signals into the chirp rate-quadratic chirp rate (CR-QCR) domains. It can greatly suppress the cross-terms while strengthening the auto-terms by multiplying different CR-QCR domains with different scale factors. Compared with high order ambiguity function-integrated cubic phase function and modified Lv's distribution, the simulation results verify that the 2D-PMPCRD acquires higher anti-noise performance and obtains better cross-terms suppression performance for multi-QFM signals with reasonable computation cost.

  17. Excitation of high-frequency electromagnetic waves by energetic electrons with a loss cone distribution in a field-aligned potential drop

    Science.gov (United States)

    Fung, Shing F.; Vinas, Adolfo F.

    1994-01-01

    The electron cyclotron maser instability (CMI) driven by momentum space anisotropy (df/dp (sub perpendicular) greater than 0) has been invoked to explain many aspects, such as the modes of propagation, harmonic emissions, and the source characteristics of the auroral kilometric radiation (AKR). Recent satellite observations of AKR sources indicate that the source regions are often imbedded within the auroral acceleration region characterized by the presence of a field-aligned potential drop. In this paper we investigate the excitation of the fundamental extraordinary mode radiation due to the accelerated electrons. The momentum space distribution of these energetic electrons is modeled by a realistic upward loss cone as modified by the presence of a parallel potential drop below the observation point. On the basis of linear growth rate calculations we present the emission characteristics, such as the frequency spectrum and the emission angular distribution as functions of the plasma parameters. We will discuss the implication of our results on the generation of the AKR from the edges of the auroral density cavities.

  18. Frequency distribution, isotopic composition and physical characterization of plutonium-bearing particles from the Fig-Quince zone on Runit Island, Enewetak Atoll

    International Nuclear Information System (INIS)

    Hamilton, T.F.; Martinelli, R.E.; Kehl, S.R.; Rivers, A.N.; Brown, T.A.; Tumey, S.J.; Jernstroeem, J.; Williams, R.W.

    2009-01-01

    Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946-58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels and distribution of residual contamination in the Fig-Quince zone, and (ii) to develop pertinent data on the frequency distribution, elemental and isotopic composition, and physico-chemical properties of hot particles isolated from surface soils from Fig-Quince with a view towards providing recommendations on the future management and possible cleanup of the site. Today, Runit Island remains under an administrative quarantine. (author)

  19. Distribution of shallow very low frequency earthquakes in the eastern Nankai trough influenced by a subducted oceanic ridge: Results from cluster analysis applied to ocean bottom seismographs

    Science.gov (United States)

    To, A.; Obana, K.; Araki, E.

    2016-12-01

    The activity of very low frequency earthquakes (VLFEs) in the shallow accretionary prism of the eastern Nankai trough has been observed frequently in the past. In this study, we investigated the distribution of VLFEs that occurred in October 2015, which were recorded by an array of broadband ocean bottom seismometers (BBOBSs) of DONET1 network. The size of the network is much wider (>80 km) compared to previous BBOBS networks that were used for close-in observations of VLFEs; therefore the new dataset provides a broader overview of the VLFE distribution of this region. We first located the detected events using conventional methods such as the envelope correlation method. However, the results seemed to be largely scattered due to noise and the effect of 3D structures that could not be properly handled. Then, we introduced hierarchal clustering analysis, based on measured travel time patterns among stations obtained for each event. The analyses enabled the assessment of relative locations among events. Finally, the locations of event-clusters were estimated, instead of individual events, so that the obtained locations seemed less scattered. The obtained results indicate that the VLFE distribution is strongly influenced by a subducted ridge (Park et al., 2003) that exists beneath the northeastern side of the DONET1 network. Though the VLFEs are distributed from an area near the outer ridge toward the trench axis in the region with a smooth plate boundary, they are clustered at a shallow depth near the outer ridge in the region of the rough plate boundary. The VLFEs are clustered on the landward side of the peak of the subducted ridge; this could be explained by an elevated pore pressure in the region caused by the low-permeability oceanic ridge that may clog the up-dip pathway of the fluid along the decollement zone. The along-strike variation of the stress state, inferred from the VLFE distribution, should be an important factor in assessing the strain release

  20. Distributional Inference

    NARCIS (Netherlands)

    Kroese, A.H.; van der Meulen, E.A.; Poortema, Klaas; Schaafsma, W.

    1995-01-01

    The making of statistical inferences in distributional form is conceptionally complicated because the epistemic 'probabilities' assigned are mixtures of fact and fiction. In this respect they are essentially different from 'physical' or 'frequency-theoretic' probabilities. The distributional form is

  1. Evolution model with a cumulative feedback coupling

    Science.gov (United States)

    Trimper, Steffen; Zabrocki, Knud; Schulz, Michael

    2002-05-01

    The paper is concerned with a toy model that generalizes the standard Lotka-Volterra equation for a certain population by introducing a competition between instantaneous and accumulative, history-dependent nonlinear feedback the origin of which could be a contribution from any kind of mismanagement in the past. The results depend on the sign of that additional cumulative loss or gain term of strength λ. In case of a positive coupling the system offers a maximum gain achieved after a finite time but the population will die out in the long time limit. In this case the instantaneous loss term of strength u is irrelevant and the model exhibits an exact solution. In the opposite case λ<0 the time evolution of the system is terminated in a crash after ts provided u=0. This singularity after a finite time can be avoided if u≠0. The approach may well be of relevance for the qualitative understanding of more realistic descriptions.

  2. Psychometric properties of the Cumulated Ambulation Score

    DEFF Research Database (Denmark)

    Ferriero, Giorgio; Kristensen, Morten T; Invernizzi, Marco

    2018-01-01

    INTRODUCTION: In the geriatric population, independent mobility is a key factor in determining readiness for discharge following acute hospitalization. The Cumulated Ambulation Score (CAS) is a potentially valuable score that allows day-to-day measurements of basic mobility. The CAS was developed...... and validated in older patients with hip fracture as an early postoperative predictor of short-term outcome, but it is also used to assess geriatric in-patients with acute medical illness. Despite the fast- accumulating literature on the CAS, to date no systematic review synthesizing its psychometric properties....... Of 49 studies identified, 17 examined the psychometric properties of the CAS. EVIDENCE SYNTHESIS: Most papers dealt with patients after hip fracture surgery, and only 4 studies assessed the CAS psychometric characteristics also in geriatric in-patients with acute medical illness. Two versions of CAS...

  3. Cumulative life events, traumatic experiences, and psychiatric symptomatology in transition-aged youth with autism spectrum disorder

    OpenAIRE

    Taylor, Julie Lounds; Gotham, Katherine O.

    2016-01-01

    Background Co-occurring mood and anxiety symptomatology is commonly observed among youth with autism spectrum disorders (ASD) during adolescence and adulthood. Yet, little is known about the factors that might predispose youth with ASD to mood and anxiety problems. In this study, we focus on the role of cumulative stressful life events and trauma in co-occurring psychopathology among youth with ASD who are preparing to exit high school. Specifically, we examined the distribution of cumulative...

  4. Colony size-frequency distributions among different populations of the scleractinan coral Siderastrea stellata in Southwestern Atlantic: implications for life history patterns

    Directory of Open Access Journals (Sweden)

    Monica Moraes Lins de Barros

    2006-12-01

    Full Text Available Colony size-frequency distributions of reef corals may be used to infer growth potential and population responses upon environmental changes. The present paper compares the size structure of colonies of Siderastrea stellata Verrill, 1868,among 11 sites, six of them distributed along a gradient of sediment deposition in Abrolhos, Bahia, Brazil (18º S. Results indicated that the population structure is likely to be influenced by local conditions, rather than large scale factors, such as latitude. The 11 distributions, however, showed higher frequencies of small size classes. Class 1 (up to 2.5 cm diameter was always present and the frequency of colonies from size class 3 (10 cm diameter tended to decrease in all sites. Comparison among the six Abrolhos sites showed that S. stellata has advantages at sites with intermediate sedimentation, where colonies attain larger sizes, probably, reflecting a higher survivorship over time. The present study showed that, despite the influence of environmental conditions on parameters of the populations such as size of colony, the life history strategy of S. stellata reflects a local adaptation that allows its development and survivorship in shallow waters and horizontal substrates, sites characterized by high mortality rates.Distribuições de freqüências de classes de tamanho de colônias de corais recifais, associadas a dados de fecundidade e crescimento, podem ser utilizadas para inferir o potencial de crescimento e respostas da população frente às variações ambientais. Apresentamos análise da estrutura de tamanho de colônias do coral Siderastrea stellata Verrill, 1868, em 11 locais, seis desses distribuídos ao longo de um gradiente de sedimentação em Abrolhos, Bahia, Brasil (18ºS. Os resultados demonstraram ausência de um padrão latitudinal, indicando maior influência de fatores locais. Em Abrolhos, locais com taxas de deposição de sedimento intermediárias apresentaram os maiores

  5. Cumulative radiation dose of multiple trauma patients during their hospitalization

    International Nuclear Information System (INIS)

    Wang Zhikang; Sun Jianzhong; Zhao Zudan

    2012-01-01

    Objective: To study the cumulative radiation dose of multiple trauma patients during their hospitalization and to analyze the dose influence factors. Methods: The DLP for CT and DR were retrospectively collected from the patients during June, 2009 and April, 2011 at a university affiliated hospital. The cumulative radiation doses were calculated by summing typical effective doses of the anatomic regions scanned. Results: The cumulative radiation doses of 113 patients were collected. The maximum,minimum and the mean values of cumulative effective doses were 153.3, 16.48 mSv and (52.3 ± 26.6) mSv. Conclusions: Multiple trauma patients have high cumulative radiation exposure. Therefore, the management of cumulative radiation doses should be enhanced. To establish the individualized radiation exposure archives will be helpful for the clinicians and technicians to make decision whether to image again and how to select the imaging parameters. (authors)

  6. Power-Law Scaling of the Impact Crater Size-Frequency Distribution on Pluto: A Preliminary Analysis Based on First Images from New Horizons' Flyby

    Directory of Open Access Journals (Sweden)

    Scholkmann F.

    2016-01-01

    Full Text Available The recent (14 th July 2015 flyby of NASA’s New Horizons spacecraft of the dwarf planet Pluto resulted in the first high-resolution images of the geological surface- features of Pluto. Since previous studies showed that the impact crater size-frequency distribution (SFD of different celestial objects of our solar system follows power-laws, the aim of the present analysis was to determine, for the first time, the power-law scaling behavior for Pluto’s crater SFD based on the first images available in mid-September 2015. The analysis was based on a high-resolution image covering parts of Pluto’s re- gions Sputnik Planum , Al-Idrisi Montes and Voyager Terra . 83 impact craters could be identified in these regions and their diameter ( D was determined. The analysis re- vealed that the crater diameter SFD shows a statistically significant power-law scaling ( α = 2.4926±0.3309 in the interval of D values ranging from 3.75±1.14 km to the largest determined D value in this data set of 37.77 km. The value obtained for the scaling coefficient α is similar to the coefficient determined for the power-law scaling of the crater SFDs from the other celestial objects in our solar system. Further analysis of Pluto’s crater SFD is warranted as soon as new images are received from the spacecraft.

  7. Analysis of Maneuvering Targets with Complex Motions by Two-Dimensional Product Modified Lv’s Distribution for Quadratic Frequency Modulation Signals

    Directory of Open Access Journals (Sweden)

    Fulong Jing

    2017-06-01

    Full Text Available For targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, azimuth echo signals can be modeled as multicomponent quadratic frequency modulation (QFM signals after migration compensation and phase adjustment. For the QFM signal model, the chirp rate (CR and the quadratic chirp rate (QCR are two important physical quantities, which need to be estimated. For multicomponent QFM signals, the cross terms create a challenge for detection, which needs to be addressed. In this paper, by employing a novel multi-scale parametric symmetric self-correlation function (PSSF and modified scaled Fourier transform (mSFT, an effective parameter estimation algorithm is proposed—referred to as the Two-Dimensional product modified Lv’s distribution (2D-PMLVD—for QFM signals. The 2D-PMLVD is simple and can be easily implemented by using fast Fourier transform (FFT and complex multiplication. These measures are analyzed in the paper, including the principle, the cross term, anti-noise performance, and computational complexity. Compared to the other three representative methods, the 2D-PMLVD can achieve better anti-noise performance. The 2D-PMLVD, which is free of searching and has no identifiability problems, is more suitable for multicomponent situations. Through several simulations and analyses, the effectiveness of the proposed estimation algorithm is verified.

  8. [Frequency and distribution of sleep problems and insomnia in the adult population in Germany: results of the German Health Interview and Examination Survey for Adults (DEGS1)].

    Science.gov (United States)

    Schlack, R; Hapke, U; Maske, U; Busch, M; Cohrs, S

    2013-05-01

    Sleep disturbances are associated with a variety of physical and mental health disorders and cause high direct and indirect economic costs. The aim of this study was to report the frequency and distribution of problems of sleep onset and maintaining sleep, sleep quality, effective sleep time, and the consumption of sleeping pills in the adult population in Germany. During the 4 weeks prior to the interview, about one third of the respondents reported potentially clinically relevant problems initiating or maintaining sleep; about one-fifth reported poor quality of sleep. When additionally considering impairments during the daytime such as daytime fatigue or exhaustion, a prevalence of 5.7 % for an insomnia syndrome was found. Women were twice as likely to be affected by insomnia-syndrome as men. Significant age differences were not seen. Persons with low socioeconomic status had an increased risk of insomnia (OR: 3.44) as did people residing in West Germany (OR: 1.53). Women with low socioeconomic status (OR: 4.12) and West German men (OR: 1.79) were more affected. The results illustrate the considerable public health relevance of insomnia-related sleep disturbances. An English full-text version of this article is available at SpringerLink as supplemental.

  9. Model-checking techniques based on cumulative residuals.

    Science.gov (United States)

    Lin, D Y; Wei, L J; Ying, Z

    2002-03-01

    Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.

  10. 7 CFR 42.132 - Determining cumulative sum values.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Determining cumulative sum values. 42.132 Section 42... Determining cumulative sum values. (a) The parameters for the on-line cumulative sum sampling plans for AQL's... 3 1 2.5 3 1 2 1 (b) At the beginning of the basic inspection period, the CuSum value is set equal to...

  11. Improving cumulative effects assessment in Alberta: Regional strategic assessment

    International Nuclear Information System (INIS)

    Johnson, Dallas; Lalonde, Kim; McEachern, Menzie; Kenney, John; Mendoza, Gustavo; Buffin, Andrew; Rich, Kate

    2011-01-01

    The Government of Alberta, Canada is developing a regulatory framework to better manage cumulative environmental effects from development in the province. A key component of this effort is regional planning, which will lay the primary foundation for cumulative effects management into the future. Alberta Environment has considered the information needs of regional planning and has concluded that Regional Strategic Assessment may offer significant advantages if integrated into the planning process, including the overall improvement of cumulative environmental effects assessment in the province.

  12. The use of the multi-cumulant tensor analysis for the algorithmic optimisation of investment portfolios

    Science.gov (United States)

    Domino, Krzysztof

    2017-02-01

    The cumulant analysis plays an important role in non Gaussian distributed data analysis. The shares' prices returns are good example of such data. The purpose of this research is to develop the cumulant based algorithm and use it to determine eigenvectors that represent investment portfolios with low variability. Such algorithm is based on the Alternating Least Square method and involves the simultaneous minimisation 2'nd- 6'th cumulants of the multidimensional random variable (percentage shares' returns of many companies). Then the algorithm was tested during the recent crash on the Warsaw Stock Exchange. To determine incoming crash and provide enter and exit signal for the investment strategy the Hurst exponent was calculated using the local DFA. It was shown that introduced algorithm is on average better that benchmark and other portfolio determination methods, but only within examination window determined by low values of the Hurst exponent. Remark that the algorithm is based on cumulant tensors up to the 6'th order calculated for a multidimensional random variable, what is the novel idea. It can be expected that the algorithm would be useful in the financial data analysis on the world wide scale as well as in the analysis of other types of non Gaussian distributed data.

  13. Children neglected: Where cumulative risk theory fails.

    Science.gov (United States)

    O'Hara, Mandy; Legano, Lori; Homel, Peter; Walker-Descartes, Ingrid; Rojas, Mary; Laraque, Danielle

    2015-07-01

    Neglected children, by far the majority of children maltreated, experience an environment most deficient in cognitive stimulation and language exchange. When physical abuse co-occurs with neglect, there is more stimulation through negative parent-child interaction, which may lead to better cognitive outcomes, contrary to Cumulative Risk Theory. The purpose of the current study was to assess whether children only neglected perform worse on cognitive tasks than children neglected and physically abused. Utilizing LONGSCAN archived data, 271 children only neglected and 101 children neglected and physically abused in the first four years of life were compared. The two groups were assessed at age 6 on the WPPSI-R vocabulary and block design subtests, correlates of cognitive intelligence. Regression analyses were performed, controlling for additional predictors of poor cognitive outcome, including socioeconomic variables and caregiver depression. Children only neglected scored significantly worse than children neglected and abused on the WPPSI-R vocabulary subtest (p=0.03). The groups did not differ on the block design subtest (p=0.4). This study shows that for neglected children, additional abuse may not additively accumulate risk when considering intelligence outcomes. Children experiencing only neglect may need to be referred for services that address cognitive development, with emphasis on the linguistic environment, in order to best support the developmental challenges of neglected children. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Standardization of the cumulative absolute velocity

    International Nuclear Information System (INIS)

    O'Hara, T.F.; Jacobson, J.P.

    1991-12-01

    EPRI NP-5930, ''A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set

  15. Analysis of Memory Codes and Cumulative Rehearsal in Observational Learning

    Science.gov (United States)

    Bandura, Albert; And Others

    1974-01-01

    The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. (Editor)

  16. Newton/Poisson-Distribution Program

    Science.gov (United States)

    Bowerman, Paul N.; Scheuer, Ernest M.

    1990-01-01

    NEWTPOIS, one of two computer programs making calculations involving cumulative Poisson distributions. NEWTPOIS (NPO-17715) and CUMPOIS (NPO-17714) used independently of one another. NEWTPOIS determines Poisson parameter for given cumulative probability, from which one obtains percentiles for gamma distributions with integer shape parameters and percentiles for X(sup2) distributions with even degrees of freedom. Used by statisticians and others concerned with probabilities of independent events occurring over specific units of time, area, or volume. Program written in C.

  17. Several problems of cumulative effective mass fraction in anti-seismic analysis

    International Nuclear Information System (INIS)

    Wang Wei; Sheng Feng; Li Hailong; Wen Jing; Luan Lin

    2005-01-01

    Cumulative Effective Mass Fraction (CEMF) is one of important items which sign the accuracy in antiseismic analysis. Based on the primary theories of CEMF, the paper show the influence of CEMF on the accuracy in antiseismic analysis. Moreover, some advices and ways are given to solve common problems in antiseismic analysis, such as how to increase CEMF, how to avoid the mass's loss because of the torsional frequency's being close to the frequency corresponding to the peak of seismic response spectrum, how to avoid the mass's loss because of the constraints, and so on. (authors)

  18. Lighting and energy performance for an office using high frequency dimming controls

    International Nuclear Information System (INIS)

    Li, Danny H.W.; Lam, Tony N.T.; Wong, S.L.

    2006-01-01

    Artificial lighting is one of the major electricity consuming items in many non-domestic buildings. Recently, there has been an increasing interest in incorporating daylight in architectural and building designs to reduce the electricity use and enhance greener building developments. This paper presents field measurements for a fully air conditioned open plan office using a photoelectric dimming system. Electric lighting load, indoor illuminance levels and daylight availability were systematically measured and analyzed. The general features and characteristics of the results such as electric lighting energy savings and transmitted daylight illuminance in the forms of frequency distributions and cumulative frequency distributions are presented. Daylighting theories and regression models have been developed and discussed. It has been found that energy savings in electric lighting were over 30% using the high frequency dimming controls. The results from the study would be useful and applicable to other office spaces with similar architectural layouts and daylight linked lighting control systems

  19. The EPA's human exposure research program for assessing cumulative risk in communities.

    Science.gov (United States)

    Zartarian, Valerie G; Schultz, Bradley D

    2010-06-01

    Communities are faced with challenges in identifying and prioritizing environmental issues, taking actions to reduce their exposures, and determining their effectiveness for reducing human health risks. Additional challenges include determining what scientific tools are available and most relevant, and understanding how to use those tools; given these barriers, community groups tend to rely more on risk perception than science. The U.S. Environmental Protection Agency's Office of Research and Development, National Exposure Research Laboratory (NERL) and collaborators are developing and applying tools (models, data, methods) for enhancing cumulative risk assessments. The NERL's "Cumulative Communities Research Program" focuses on key science questions: (1) How to systematically identify and prioritize key chemical stressors within a given community?; (2) How to develop estimates of exposure to multiple stressors for individuals in epidemiologic studies?; and (3) What tools can be used to assess community-level distributions of exposures for the development and evaluation of the effectiveness of risk reduction strategies? This paper provides community partners and scientific researchers with an understanding of the NERL research program and other efforts to address cumulative community risks; and key research needs and opportunities. Some initial findings include the following: (1) Many useful tools exist for components of risk assessment, but need to be developed collaboratively with end users and made more comprehensive and user-friendly for practical application; (2) Tools for quantifying cumulative risks and impact of community risk reduction activities are also needed; (3) More data are needed to assess community- and individual-level exposures, and to link exposure-related information with health effects; and (4) Additional research is needed to incorporate risk-modifying factors ("non-chemical stressors") into cumulative risk assessments. The products of this

  20. Cumulative Effect of Depression on Dementia Risk

    Directory of Open Access Journals (Sweden)

    J. Olazarán

    2013-01-01

    Full Text Available Objective. To analyze a potential cumulative effect of life-time depression on dementia and Alzheimer’s disease (AD, with control of vascular factors (VFs. Methods. This study was a subanalysis of the Neurological Disorders in Central Spain (NEDICES study. Past and present depression, VFs, dementia status, and dementia due to AD were documented at study inception. Dementia status was also documented after three years. Four groups were created according to baseline data: never depression (nD, past depression (pD, present depression (prD, and present and past depression (prpD. Logistic regression was used. Results. Data of 1,807 subjects were investigated at baseline (mean age 74.3, 59.3% women, and 1,376 (81.6% subjects were evaluated after three years. The prevalence of dementia at baseline was 6.7%, and dementia incidence was 6.3%. An effect of depression was observed on dementia prevalence (OR [CI 95%] 1.84 [1.01–3.35] for prD and 2.73 [1.08–6.87] for prpD, and on dementia due to AD (OR 1.98 [0.98–3.99] for prD and OR 3.98 [1.48–10.71] for prpD (fully adjusted models, nD as reference. Depression did not influence dementia incidence. Conclusions. Present depression and, particularly, present and past depression are associated with dementia at old age. Multiple mechanisms, including toxic effect of depression on hippocampal neurons, plausibly explain these associations.

  1. Thermal and single frequency counter-current ultrasound pretreatments of sodium caseinate: enzymolysis kinetics and thermodynamics, amino acids composition, molecular weight distribution and antioxidant peptides.

    Science.gov (United States)

    Abdualrahman, Mohammed Adam Y; Ma, Haile; Zhou, Cunshan; Yagoub, Abu ElGasim A; Hu, Jiali; Yang, Xue

    2016-12-01

    Due to the disadvantages of traditional enzymolysis, pretreatments are crucial to enhance protein enzymolysis. Enzymolysis kinetics and thermodynamics, amino acids composition, molecular weight distribution, fluorescence spectroscopy and antioxidant activity of thermal (HT) and single frequency counter-current ultrasound (SCFU) pretreated sodium caseinate (NaCas) were studied. Enzymolysis of untreated NaCas (control) improved significantly (P < 0.05) by SFCU and followed by HT. Values of the Michaelis-Menten constant (K M ) of SFCU and HT were 0.0212 and 0.0250, respectively. HT and SFCU increased (P < 0.05) the reaction rate constant (k) by 38.64 and 90.91%, respectively at 298 K. k values decreased with increasing temperature. The initial activation energy (46.39 kJ mol -1 ) reduced (P < 0.05) by HT (39.66 kJ mol -1 ) and further by SFCU (33.42 kJ mol -1 ). SFCU-pretreated NaCas hydrolysates had the highest contents of hydrophobic, aromatic, positively and negatively charged amino acids. Medium-sized peptides (5000-1000 Da) are higher in SFCU (78.11%) than HT and the control. SFCU induced molecular unfolding of NaCas proteins. Accordingly, SFCU-pretreated NaCas hydrolysate exhibited the highest scavenging activity on DPPH and hydroxyl radicals, reducing power, and iron chelating ability. SFCU pretreatment would be a useful tool for production of bioactive peptides from NaCas hydrolysate. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. Magnitude-frequency and Spatial Distribution of Rockfalls in the White Canyon, British Columbia using Terrestrial LiDAR and Microseismic Monitoring Systems

    Science.gov (United States)

    van Veen, M.

    2015-12-01

    Transportation corridors built along natural slopes are subject to frequent rockfall hazards, which can disrupt service and cause damage to infrastructure. Many of these areas exist along the Fraser-Thompson corridor of the CN rail line in Southern British Columbia, particularly in the White Canyon area near Lytton. Here the rail track is situated between the 500 m high slopes and the river, for 2.4 km. The frequency-magnitude relationship between these events and the percentage of rockfalls making it to track level are important components of hazard assessment for these slopes. Traditional methods of collecting rockfall data in this area involve visual inspection by maintenance personnel, however this is an onerous task for such a large slope with frequent rockfall activity, and therefore the rockfall record for this area is often lacking data. Since 2012, high-resolution terrestrial LiDAR (Light detection and ranging) data has been collected for the White Canyon area and analysis of change from sequential LiDAR scans provides detailed data that can't be obtained from traditional rockfall databases, including the magnitude and spatial distribution of rockfall events. While the LiDAR change detection can be useful in identifying rockfall volumes and source zones, it can be difficult to determine the end location of each rockfall and the exact timing of events, as scan data is usually collected over a period of several months. Recently, a microseismic monitoring system has been deployed over a section of the railway track and data is available on time and location of impact at the track level, which permits assessment of the number of rockfalls traversing the whole slope down to track level. This, in combination with data on rockfall magnitudes and source zones obtained from the LiDAR change detection can provide useful information for management of tracks in these hazardous settings and also provides data for calibration of rockfall modelling.

  3. A Framework for Treating Cumulative Trauma with Art Therapy

    Science.gov (United States)

    Naff, Kristina

    2014-01-01

    Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…

  4. Cumulative effects of forest management activities: how might they occur?

    Science.gov (United States)

    R. M. Rice; R. B. Thomas

    1985-01-01

    Concerns are often voiced about possible environmental damage as the result of the cumulative sedimentation effects of logging and forest road construction. In response to these concerns, National Forests are developing procedures to reduce the possibility that their activities may lead to unacceptable cumulative effects

  5. Cumulative effect in multiple production processes on nuclei

    International Nuclear Information System (INIS)

    Golubyatnikova, E.S.; Shmonin, V.L.; Kalinkin, B.N.

    1989-01-01

    It is shown that the cumulative effect is a natural result of the process of hadron multiple production in nuclear reactions. Interpretation is made of the universality of slopes of inclusive spectra and other characteristics of cumulative hadrons. The character of information from such reactions is discussed, which could be helpful in studying the mechanism of multiparticle production. 27 refs.; 4 figs

  6. Cumulative particle production in the quark recombination model

    International Nuclear Information System (INIS)

    Gavrilov, V.B.; Leksin, G.A.

    1987-01-01

    Production of cumulative particles in hadron-nuclear inteactions at high energies is considered within the framework of recombination quark model. Predictions for inclusive cross sections of production of cumulative particles and different resonances containing quarks in s state are made

  7. Cumulative t-link threshold models for the genetic analysis of calving ease scores

    Directory of Open Access Journals (Sweden)

    Tempelman Robert J

    2003-09-01

    Full Text Available Abstract In this study, a hierarchical threshold mixed model based on a cumulative t-link specification for the analysis of ordinal data or more, specifically, calving ease scores, was developed. The validation of this model and the Markov chain Monte Carlo (MCMC algorithm was carried out on simulated data from normally and t4 (i.e. a t-distribution with four degrees of freedom distributed populations using the deviance information criterion (DIC and a pseudo Bayes factor (PBF measure to validate recently proposed model choice criteria. The simulation study indicated that although inference on the degrees of freedom parameter is possible, MCMC mixing was problematic. Nevertheless, the DIC and PBF were validated to be satisfactory measures of model fit to data. A sire and maternal grandsire cumulative t-link model was applied to a calving ease dataset from 8847 Italian Piemontese first parity dams. The cumulative t-link model was shown to lead to posterior means of direct and maternal heritabilities (0.40 ± 0.06, 0.11 ± 0.04 and a direct maternal genetic correlation (-0.58 ± 0.15 that were not different from the corresponding posterior means of the heritabilities (0.42 ± 0.07, 0.14 ± 0.04 and the genetic correlation (-0.55 ± 0.14 inferred under the conventional cumulative probit link threshold model. Furthermore, the correlation (> 0.99 between posterior means of sire progeny merit from the two models suggested no meaningful rerankings. Nevertheless, the cumulative t-link model was decisively chosen as the better fitting model for this calving ease data using DIC and PBF.

  8. MOCARS: a Monte Carlo code for determining the distribution and simulation limits

    International Nuclear Information System (INIS)

    Matthews, S.D.

    1977-07-01

    MOCARS is a computer program designed for the INEL CDC 76-173 operating system to determine the distribution and simulation limits for a function by Monte Carlo techniques. The code randomly samples data from any of the 12 user-specified distributions and then either evaluates the cut set system unavailability or a user-specified function with the sample data. After the data are ordered, the values at various quantities and associated confidence bounds are calculated for output. Also available for output on microfilm are the frequency and cumulative distribution histograms from the sample data. 29 figures, 4 tables

  9. Integração entre curvas de permanência de quantidade e qualidade da água como uma ferramenta para a gestão eficiente dos recursos hídricos Integration between cumulative frequency curves for water quantity and quality as a tool for effective water resources management

    Directory of Open Access Journals (Sweden)

    Davi Gasparini Fernandes Cunha

    2012-12-01

    Full Text Available A garantia dos usos múltiplos da água, dos serviços ambientais e do equilíbrio ecológico depende de uma combinação adequada entre aspectos quantitativos e qualitativos dos rios. A presente pesquisa descreve aplicações de uma nova abordagem das curvas de permanência de vazões, que foram associadas a curvas de frequência acumulada de qualidade da água. Foram compilados dados de fósforo total (2005 a 2009 e vazão média mensal (1959 a 2003 dos rios Paraíba do Sul e Sorocaba para ilustrar o conceito. A integração entre as curvas de quantidade e qualidade se mostrou desejável por oferecer subsídios a concessões de outorga, à cobrança pelo uso da água, ao monitoramento ambiental e ao enquadramento dos cursos de água. Outro aspecto positivo é que essas curvas podem incorporar variações no clima e no uso e ocupação do solo, o que permite o estabelecimento de cenários ambientais.The security of the different water uses, environmental services and ecological balance depends upon a well-weighted combination between quantitative and qualitative aspects in rivers. This research describes applications of a new approach of the frequency curves for discharge, which were associated with frequency curves for water quality. Data on total phosphorus (2005 to 2009 and monthly average flow (1959 to 2003 from the Paraíba do Sul and Sorocaba Rivers were compiled to further illustrate the concept. The integration between the curves of water quantity and quality was considered desirable as it can aid in the planning of water concessions, charging for water uses, environmental monitoring and establishment of water quality standards and framework. Moreover, these curves can accommodate variations in climate and land use, allowing the establishment of environmental scenarios

  10. Towards Greenland Glaciation: cumulative or abrupt transition?

    Science.gov (United States)

    Ramstein, Gilles; Tan, Ning; Ladant, Jean-baptiste; Dumas, Christophe; Contoux, Camille

    2017-04-01

    During the mid-Pliocene warming period (3-3.3 Ma BP), the global annual mean temperatures inferred by data and model studies were 2-3° warmer than pre-industrial values. Accordingly, Greenland ice sheet volume is supposed to reach at the most, only half of that of present-day [Haywood et al. 2010]. Around 2.7-2.6 Ma BP, just ˜ 500 kyr after the warming peak of mid-Pliocene, the Greenland ice sheet has reached its full size [Lunt et al. 2008]. A crucial question concerns the evolution of the Greenland ice sheet from half to full size during the 3 - 2.5 Ma period. Data show a decreasing trend of atmospheric CO2 concentration from 3 Ma to 2.5 Ma [Seki et al.2010; Bartoli et al. 2011; Martinez et al. 2015]. However, a recent study [Contoux et al. 2015] suggests that a lowering of CO2 is not sufficient to initiate a perennial glaciation on Greenland and must be combined with low summer insolation to preserve the ice sheet during insolation maxima. This suggests rather a cumulative process than an abrupt event. In order to diagnose the evolution of the ice sheet build-up, we carry on, for the first time, a transient simulation of climate and ice sheet evolutions from 3 Ma to 2.5 Ma. This strategy enables us to investigate the waxing and waning of the ice sheet during several orbital cycles. We use a tri-dimensional interpolation method designed by Ladant et al. (2014), which allows the evolution of CO2 concentration and of orbital parameters, and the evolution of the Greenland ice sheet size to be taken into account. By interpolating climatic snapshot simulations ran with various possible combinations of CO2, orbits and ice sheet sizes, we can build a continuous climatic forcing that is then used to provide 500 kyrs-long ice sheet simulations. With such a tool, we may offer a physically based answer to different CO2 reconstructions scenarios and analyse which one is the most consistent with Greenland ice sheet buildup.

  11. An Analysis of Cumulative Risks Indicated by Biomonitoring Data of Six Phthalates Using the Maximum Cumulative Ratio

    Science.gov (United States)

    The Maximum Cumulative Ratio (MCR) quantifies the degree to which a single component of a chemical mixture drives the cumulative risk of a receptor.1 This study used the MCR, the Hazard Index (HI) and Hazard Quotient (HQ) to evaluate co-exposures to six phthalates using biomonito...

  12. An analysis of cumulative risks based on biomonitoring data for six phthalates using the Maximum Cumulative Ratio

    Science.gov (United States)

    The Maximum Cumulative Ratio (MCR) quantifies the degree to which a single chemical drives the cumulative risk of an individual exposed to multiple chemicals. Phthalates are a class of chemicals with ubiquitous exposures in the general population that have the potential to cause ...

  13. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    International Nuclear Information System (INIS)

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2008-01-01

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g -1 . Linear regression of whole tooth lead (μg g -1 ) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r 2 =0.647 (p -1 , were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g -1 ) on cumulative lead dose (g) yielded a slope of 23 with r 2 =0.961 (p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats

  14. Cumulative Impact Assessment: Approaching Environmental Capacity in Development Area Using Environmental Impact Assessment Information

    Science.gov (United States)

    Cho, N.; Lee, M. J.; Maeng, J. H.

    2017-12-01

    Environmental impact assessment estimates the impact of development as a business unit and establishes mitigation plan. If the development is done, its economic effects can spread to the nearby areas. So that various developments can be distributed at different time intervals. The impact of the new developments can be combined with existing environmental impacts and can have a larger impact. That is, Cumulative impact assessment is needed to consider the environmental capacity of the Nearby area. Cumulative impact assessments require policy tools such as environmental impact assessment information and cumulative impact estimation models. In Korea, environmental information (water quality, air quality, etc.) of the development site is measured for environmental impact assessment and monitored for a certain period (generally 5 years) after the project. In addition, by constructing the environmental information as a spatial database, it is possible to express the environmental impact on a regional basis spatially and to intuitively use it for development site selection. Utilizing a composite model of environmental impact assessment information and Remote Sensing data for cumulative impact estimation, That can be used as a policy decision support tool that provides quantitative information for development area management, such as time series effect and sprawl phenomenon.

  15. Integrating environmental monitoring with cumulative effects management and decision making.

    Science.gov (United States)

    Cronmiller, Joshua G; Noble, Bram F

    2018-05-01

    Cumulative effects (CE) monitoring is foundational to emerging regional and watershed CE management frameworks, yet monitoring is often poorly integrated with CE management and decision-making processes. The challenges are largely institutional and organizational, more so than scientific or technical. Calls for improved integration of monitoring with CE management and decision making are not new, but there has been limited research on how best to integrate environmental monitoring programs to ensure credible CE science and to deliver results that respond to the more immediate questions and needs of regulatory decision makers. This paper examines options for the integration of environmental monitoring with CE frameworks. Based on semistructured interviews with practitioners, regulators, and other experts in the Lower Athabasca, Alberta, Canada, 3 approaches to monitoring system design are presented. First, a distributed monitoring system, reflecting the current approach in the Lower Athabasca, where monitoring is delegated to different external programs and organizations; second, a 1-window system in which monitoring is undertaken by a single, in-house agency for the purpose of informing management and regulatory decision making; third, an independent system driven primarily by CE science and understanding causal relationships, with knowledge adopted for decision support where relevant to specific management questions. The strengths and limitations of each approach are presented. A hybrid approach may be optimal-an independent, nongovernment, 1-window model for CE science, monitoring, and information delivery-capitalizing on the strengths of distributed, 1-window, and independent monitoring systems while mitigating their weaknesses. If governments are committed to solving CE problems, they must invest in the long-term science needed to do so; at the same time, if science-based monitoring programs are to be sustainable over the long term, they must be responsive to

  16. Prediction of the cumulated dose for external beam irradiation of prostate cancer patients with 3D-CRT technique

    Directory of Open Access Journals (Sweden)

    Giżyńska Marta

    2016-03-01

    Full Text Available Nowadays in radiotherapy, much effort is taken to minimize the irradiated volume and consequently minimize doses to healthy tissues. In our work, we tested the hypothesis that the mean dose distribution calculated from a few first fractions can serve as prediction of the cumulated dose distribution, representing the whole treatment. We made our tests for 25 prostate cancer patients treated with three orthogonal fields technique. We did a comparison of dose distribution calculated as a sum of dose distribution from each fraction with a dose distribution calculated with isocenter shifted for a mean setup error from a few first fractions. The cumulative dose distribution and predicted dose distributions are similar in terms of gamma (3 mm 3% analysis, under condition that we know setup error from seven first fractions. We showed that the dose distribution calculated for the original plan with the isocenter shifted to the point, defined as the original isocenter corrected of the mean setup error estimated from the first seven fractions supports our hypothesis, i.e. can serve as a prediction for cumulative dose distribution.

  17. {sup 18}F-PET imaging: frequency, distribution and appearance of benign lesions; Die Positronenemissionstomographie des Skelettsystems mit {sup 18}FNa: Haeufigkeit, Befundmuster und Verteilung benigner Veraenderungen

    Energy Technology Data Exchange (ETDEWEB)

    Schirrmeister, H.; Kotzerke, J.; Rentschler, M.; Traeger, H.; Fenchel, S.; Diederichs, C.G.; Reske, S.N. [Ulm Univ. (Germany). Abt. Nuklearmedizin; Nuessle, K. [Ulm Univ. (Germany). Abt. fuer Roentgendiagnostik

    1998-09-01

    Purpose: We evaluated the frequency, distribution and appearance of benign lesions in {sup 18}F-PET scans. Methods: Between March 1996 and May 1997, {sup 18}F-PET scans were performed in 59 patients in addition to conventional planar bone scintigraphy. Eleven patients were subjected to additional SPECT imaging. The main indication was searching for bone metastases (58 pat.). The diagnosis was confirmed radiologically. Results: With {sup 18}F-PET in 39 patients (66,1%) 152 benign lesions, mostly located in the spine were detected. {sup 99m}Tc bone scans revealed 45 lesions in 10 patients. Osteoarthritis of the intervertebral articulations (69%) or of the acromioclavicular joint (15%) were the most common reasons for degenerative lesions detected with {sup 18}F-PET. Osteophytes appeared as hot lesions located at two adjacent vertebral endplates. Osteoarthritis of the intervertebral articulations showed an enhanced tracer uptake at these localizations, whereas endplate fractures of the vertebral bodies appeared very typically; solitary fractures of the ribs could not be differentiated from metastases. Rare benign lesions were not studied. Conclusion: Most of the degenerative lesions (84%) detected with {sup 18}F-PET had a very typical appearance and could be detected with the improved spatial resolution and advantages of a tomographic technique. {sup 18}F-PET had an increased accuracy in detecting degenerative bone lesions. (orig.) [Deutsch] Ziel: Wir untersuchten Haeufigkeit und Befundmuster benigner Skelettveraenderungen mit {sup 18}F-PET. Material und Methoden: Zwischen 3/96 und 5/97 untersuchten wir 59 Patienten mit {sup 18}F-PET zusaetzlich zur planaren, bei 11 Patienten durch SPECT ergaenzten konventionellen Skelettszintigraphie (KS). Hauptindikation war die Metastasensuche (58 Pat.). Die Befundkontrolle erfolgte radiologisch. Ergebnisse: {sup 18}F-PET zeigte bei 39 Patienten (66,1%) 152 meist in der Wirbelsaeule lokalisierte, benigne Mehranreicherungen. Mit der

  18. Haplotype frequency distribution for 7 microsatellites in chromosome 8 and 11 in relation to the metabolic syndrome in four ethnic groups: Tehran Lipid and Glucose Study.

    Science.gov (United States)

    Daneshpour, Maryam Sadat; Hosseinzadeh, Nima; Zarkesh, Maryam; Azizi, Fereidoun

    2012-03-01

    Different variants of haplotype frequencies may lead to various frequencies of the same variants in individuals with drug resistance and disease susceptibility at the population level. In this study, the haplotype frequencies of 4 STR loci including the D8S1132, D8S1779, D8S514 and D8S1743, and 3 STR loci including D11S1304, D11S1998 and D11S934 were investigated in 563 individuals of four Iranian ethnic groups in the capital city of Iran, Tehran. One hundred thirty subjects had the metabolic syndrome. Haplotype frequencies of all markers were calculated. There were significant differences in the haplotype frequencies in short and long alleles between the metabolic affected subjects and controls. In addition, haplotype frequencies were significant in the four ethnic groups in both chromosomes 8 and 11. Our findings show a relation between the short allele of D8S1743 in all related haplotype frequencies of subjects with metabolic syndrome. These findings may require more studies of some candidate genes, including the lipoprotein lipase gene, in this chromosomal region. Copyright © 2011. Published by Elsevier B.V.

  19. Low-frequency observations of Galactic supernova remnants and the distribution of low-density ionized gas in the interstellar medium

    International Nuclear Information System (INIS)

    Kassim, N.E.

    1989-01-01

    New long-wavelength observations of Galactic SNRs at 30.9 and 57.5 MHz are used to derive detailed low-frequency radio spectra for 32 SNRs. Of these, about two-thirds show turnovers at low frequencies, implying the presence of a widespread, but inhomogeneous, ionized absorbing medium along the lines of sight. These observations are combined with other low-frequency data to derive free-free optical depths toward 457 SNRs and to constrain the physical properties of the ionized gas responsible for the absorption. These optical depths are consistent with the expected absorbing properties of extended H II region envelopes. 43 refs

  20. Modelling the Frequency of Operational Risk Losses under the Basel II Capital Accord: A Comparative study of Poisson and Negative Binomial Distributions

    OpenAIRE

    Silver, Toni O.

    2013-01-01

    2013 dissertation for MSc in Finance and Risk Management. Selected by academic staff as a good example of a masters level dissertation. \\ud \\ud This study investigated the two major methods of modelling the frequency of\\ud operational losses under the BCBS Accord of 1998 known as Basel II Capital\\ud Accord. It compared the Poisson method of modelling the frequency of\\ud losses to that of the Negative Binomial. The frequency of operational losses\\ud was investigated using a cross section of se...