Directory of Open Access Journals (Sweden)
Borna Müller
Full Text Available BACKGROUND: Bovine tuberculosis (BTB today primarily affects developing countries. In Africa, the disease is present essentially on the whole continent; however, little accurate information on its distribution and prevalence is available. Also, attempts to evaluate diagnostic tests for BTB in naturally infected cattle are scarce and mostly complicated by the absence of knowledge of the true disease status of the tested animals. However, diagnostic test evaluation in a given setting is a prerequisite for the implementation of local surveillance schemes and control measures. METHODOLOGY/PRINCIPAL FINDINGS: We subjected a slaughterhouse population of 954 Chadian cattle to single intra-dermal comparative cervical tuberculin (SICCT testing and two recently developed fluorescence polarization assays (FPA. Using a Bayesian modeling approach we computed the receiver operating characteristic (ROC curve of each diagnostic test, the true disease prevalence in the sampled population and the disease status of all sampled animals in the absence of knowledge of the true disease status of the sampled animals. In our Chadian setting, SICCT performed better if the cut-off for positive test interpretation was lowered from >4 mm (OIE standard cut-off to >2 mm. Using this cut-off, SICCT showed a sensitivity and specificity of 66% and 89%, respectively. Both FPA tests showed sensitivities below 50% but specificities above 90%. The true disease prevalence was estimated at 8%. Altogether, 11% of the sampled animals showed gross visible tuberculous lesions. However, modeling of the BTB disease status of the sampled animals indicated that 72% of the suspected tuberculosis lesions detected during standard meat inspections were due to other pathogens than Mycobacterium bovis. CONCLUSIONS/SIGNIFICANCE: Our results have important implications for BTB diagnosis in a high incidence sub-Saharan African setting and demonstrate the practicability of our Bayesian approach for
Lachin, John M
2006-10-15
Various methods have been described for re-estimating the final sample size in a clinical trial based on an interim assessment of the treatment effect. Many re-weight the observations after re-sizing so as to control the pursuant inflation in the type I error probability alpha. Lan and Trost (Estimation of parameters and sample size re-estimation. Proceedings of the American Statistical Association Biopharmaceutical Section 1997; 48-51) proposed a simple procedure based on conditional power calculated under the current trend in the data (CPT). The study is terminated for futility if CPT or = CU, or re-sized by a factor m to yield CPT = CU if CL stopping for futility can balance the inflation due to sample size re-estimation, thus permitting any form of final analysis with no re-weighting. Herein the statistical properties of this approach are described including an evaluation of the probabilities of stopping for futility or re-sizing, the distribution of the re-sizing factor m, and the unconditional type I and II error probabilities alpha and beta. Since futility stopping does not allow a type I error but commits a type II error, then as the probability of stopping for futility increases, alpha decreases and beta increases. An iterative procedure is described for choice of the critical test value and the futility stopping boundary so as to ensure that specified alpha and beta are obtained. However, inflation in beta is controlled by reducing the probability of futility stopping, that in turn dramatically increases the possible re-sizing factor m. The procedure is also generalized to limit the maximum sample size inflation factor, such as at m max = 4. However, doing so then allows for a non-trivial fraction of studies to be re-sized at this level that still have low conditional power. These properties also apply to other methods for sample size re-estimation with a provision for stopping for futility. Sample size re-estimation procedures should be used with caution
Properties of Estimated Characteristic Roots
DEFF Research Database (Denmark)
Nielsen, Bent; Nielsen, Heino Bohn
Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...
Operator estimates in homogenization theory
Zhikov, V. V.; Pastukhova, S. E.
2016-06-01
This paper gives a systematic treatment of two methods for obtaining operator estimates: the shift method and the spectral method. Though substantially different in mathematical technique and physical motivation, these methods produce basically the same results. Besides the classical formulation of the homogenization problem, other formulations of the problem are also considered: homogenization in perforated domains, the case of an unbounded diffusion matrix, non-self-adjoint evolution equations, and higher-order elliptic operators. Bibliography: 62 titles.
Cable historical operating temperature estimator
Energy Technology Data Exchange (ETDEWEB)
Leon de, F.; St-Roch, P.; Beauregard, C. [Cyme International, St-Bruno, PQ (Canada)
2006-07-01
A tool designed to accurately determine the thermal age of underground cables was described. The cable historical operating temperature estimate (CHOTE) is a software application designed to identify which cables have exceeded their normal and emergency operating temperatures. CHOTE is also capable of predicting when cables are likely to reach their maximum design temperature in the future. The system operates by processing archived loading information from data acquisition systems in order to automatically analyze all the thermal sections of a system. Cables that exceed their emergency and normal temperatures for the longest amount of time are ranked first, and outputs display when and where the hot spots have occurred. CHOTE is also able to study the impact of the addition of new cables and to determine the remaining ampacity of cables installed in a given duct bank. It was concluded that the CHOTE system can help in the efficient management of cable repairs and installations. 28 refs., 7 figs.
Properties of Estimated Characteristic Roots
DEFF Research Database (Denmark)
Nielsen, Bent; Nielsen, Heino Bohn
Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...... when multiple roots are present as this imply a non-differentiability so the d-method does not apply, convergence rates are slow, and the asymptotic distribution is non-normal. In finite samples this has a considerable influence on the finite sample distribution unless the roots are far apart....... With increasing order of the autoregressions it becomes increasingly difficult to place the roots far apart giving a very noisy signal from the characteristic roots....
Weighted Estimates for Toeplitz Operators Related to Pseudodifferential Operators
Directory of Open Access Journals (Sweden)
Yan Lin
2016-01-01
Full Text Available The authors establish the weighted Lp estimates for a class of pseudodifferential operators for both cases 1
estimates for the Toeplitz operators related to pseudodifferential operators are also obtained. As their special cases, the corresponding results for the commutators of pseudodifferential operators can be deduced.
NONPARAMETRIC ESTIMATION OF CHARACTERISTICS OF PROBABILITY DISTRIBUTIONS
Directory of Open Access Journals (Sweden)
Orlov A. I.
2015-10-01
Full Text Available The article is devoted to the nonparametric point and interval estimation of the characteristics of the probabilistic distribution (the expectation, median, variance, standard deviation, variation coefficient of the sample results. Sample values are regarded as the implementation of independent and identically distributed random variables with an arbitrary distribution function having the desired number of moments. Nonparametric analysis procedures are compared with the parametric procedures, based on the assumption that the sample values have a normal distribution. Point estimators are constructed in the obvious way - using sample analogs of the theoretical characteristics. Interval estimators are based on asymptotic normality of sample moments and functions from them. Nonparametric asymptotic confidence intervals are obtained through the use of special output technology of the asymptotic relations of Applied Statistics. In the first step this technology uses the multidimensional central limit theorem, applied to the sums of vectors whose coordinates are the degrees of initial random variables. The second step is the conversion limit multivariate normal vector to obtain the interest of researcher vector. At the same considerations we have used linearization and discarded infinitesimal quantities. The third step - a rigorous justification of the results on the asymptotic standard for mathematical and statistical reasoning level. It is usually necessary to use the necessary and sufficient conditions for the inheritance of convergence. This article contains 10 numerical examples. Initial data - information about an operating time of 50 cutting tools to the limit state. Using the methods developed on the assumption of normal distribution, it can lead to noticeably distorted conclusions in a situation where the normality hypothesis failed. Practical recommendations are: for the analysis of real data we should use nonparametric confidence limits
McLaughlin, Douglas B
2012-10-01
Field data relating aquatic ecosystem responses with water quality constituents that are potential ecosystem stressors are being used increasingly in the United States in the derivation of water quality criteria to protect aquatic life. In light of this trend, there is a need for transparent quantitative methods to assess the performance of models that predict ecological conditions using a stressor-response relationship, a response variable threshold, and a stressor variable criterion. Analysis of receiver operating characteristics (ROC analysis) has a considerable history of successful use in medical diagnostic, industrial, and other fields for similarly structured decision problems, but its use for informing water quality management decisions involving risk-based environmental criteria is less common. In this article, ROC analysis is used to evaluate predictions of ecological response variable status for 3 water quality stressor-response data sets. Information on error rates is emphasized due in part to their common use in environmental studies to describe uncertainty. One data set is comprised of simulated data, and 2 involve field measurements described previously in the literature. These data sets are also analyzed using linear regression and conditional probability analysis for comparison. Results indicate that of the methods studied, ROC analysis provides the most comprehensive characterization of prediction error rates including false positive, false negative, positive predictive, and negative predictive errors. This information may be used along with other data analysis procedures to set quality objectives for and assess the predictive performance of risk-based criteria to support water quality management decisions.
Some characteristics of offshore operations
Directory of Open Access Journals (Sweden)
Popov Đorđe
2011-01-01
Full Text Available Offshore operations are not on the margins of the world economy. They are an integral part of modern business practice. They have become one of the most important instruments in the contemporary globalized financial system. Offshore operations and tax havens are not only conduits for tax avoidance and evasion but belong more broadly to the world of finance, for the business of managing the monetary resources of an organization, country or individuals. Offshore business operating in tax havens is at the heart of a particular type of globalization that is characterized by a growing gap between the very rich and everyone else. Tax havens are financial conduits that, in exchange for a fee, use their one principal asset- their sovereignty to serve a nonresident constituency of accountants and lawyers, bankers and financiers, who bring a demand for offshore operations.
Pointwise estimates of pseudo-differential operators
DEFF Research Database (Denmark)
Johnsen, Jon
2011-01-01
As a new technique it is shown how general pseudo-differential operators can be estimated at arbitrary points in Euclidean space when acting on functions u with compact spectra. The estimate is a factorisation inequality, in which one factor is the Peetre–Fefferman–Stein maximal function of u...
Pointwise estimates of pseudo-differential operators
DEFF Research Database (Denmark)
Johnsen, Jon
As a new technique it is shown how general pseudo-differential operators can be estimated at arbitrary points in Euclidean space when acting on functions u with compact spectra.The estimate is a factorisation inequality, in which one factor is the Peetre–Fefferman–Stein maximal function of u...
49 CFR 236.717 - Characteristics, operating.
2010-10-01
..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.717 Characteristics, operating. The measure of electrical values at which electrical or...
Parameter estimation in LISA Pathfinder operational exercises
Nofrarias, Miquel; Congedo, Giuseppe; Hueller, Mauro; Armano, M; Diaz-Aguilo, M; Grynagier, A; Hewitson, M
2011-01-01
The LISA Pathfinder data analysis team has been developing in the last years the infrastructure and methods required to run the mission during flight operations. These are gathered in the LTPDA toolbox, an object oriented MATLAB toolbox that allows all the data analysis functionalities for the mission, while storing the history of all operations performed to the data, thus easing traceability and reproducibility of the analysis. The parameter estimation methods in the toolbox have been applied recently to data sets generated with the OSE (Off-line Simulations Environment), a detailed LISA Pathfinder non-linear simulator that will serve as a reference simulator during mission operations. These operational exercises aim at testing the on-orbit experiments in a realistic environment in terms of software and time constraints. These simulations, so called operational exercises, are the last verification step before translating these experiments into tele-command sequences for the spacecraft, producing therefore ve...
On some numerical characteristics of operators
Directory of Open Access Journals (Sweden)
M. Gürdal
2015-01-01
Full Text Available We investigate some numerical characteristics of Toeplitz operators including the numerical range, maximal numerical range and maximal Berezin set. Further, we establish an inequality for the Berezin number of an arbitrary operator on the Hardy–Hilbert space of the unit disc.
Exponential decay estimates for Singular Integral operators
Ortiz-Caraballo, Carmen; Rela, Ezequiel
2012-01-01
The following subexponential estimate for commutators is proved |[|\\{x\\in Q: |[b,T]f(x)|>tM^2f(x)\\}|\\leq c\\,e^{-\\sqrt{\\alpha\\, t\\|b\\|_{BMO}}}\\, |Q|, \\qquad t>0.\\] where $c$ and $\\alpha$ are absolute constants, $T$ is a Calder\\'on--Zygmund operator, $M$ is the Hardy Littlewood maximal function and $f$ is any function supported on the cube $Q$. It is also obtained \\[|\\{x\\in Q: |f(x)-m_f(Q)|>tM_{1/4;Q}^#(f)(x) \\}|\\le c\\, e^{-\\alpha\\,t}|Q|,\\qquad t>0,\\] where $m_f(Q)$ is the median value of $f$ on the cube $Q$ and $M_{1/4;Q}^#$ is Str\\"omberg's local sharp maximal function. As a consequence it is derived Karagulyan's estimate \\[|\\{x\\in Q: |Tf(x)|> tMf(x)\\}|\\le c\\, e^{-c\\, t}\\,|Q|\\qquad t>0,\\] improving Buckley's theorem. A completely different approach is used based on a combination of "Lerner's formula" with some special weighted estimates of Coifman-Fefferman obtained via Rubio de Francia's algorithm. The method is flexible enough to derive similar estimates for other operators such as multilinear Calder\\'on--Z...
On scaling performance operating characteristics - Caveat emptor
Kantowitz, B. H.; Weldon, M.
1985-01-01
Problems associated with scaling and normalizing empirical performance operating characteristics (POCs) are examined. Normalization methods proposed by Wickens (1980) and by Mountford and North (1980) are critically evaluated. Computer simulations are used to generate raw-score and normalized POCs. The interpretation of transformed empirical POCs (Wickens, Mountford, and Schreiner, 1981) is shown to contain inconsistencies. The normalization techniques reviewed fail to resolve POC scaling problems. Caution must be exercised when interpreting transformed POCs.
Scalable Noise Estimation with Random Unitary Operators
Emerson, J; Zyczkowski, K; Emerson, Joseph; Alicki, Robert; Zyczkowski, Karol
2005-01-01
We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random unitary operators. In the simplest case our method enables direct estimation of the average gate fidelity. The more general fidelities are characterized by a universal exponential rate of fidelity loss. In all cases the measurable fidelity decrease is directly related to the strength of the noise affecting the implementation -- quantified by the trace of the superoperator describing the non--unitary dynamics. While the scalability of our stochastic protocol makes it most relevant in large Hilbert spaces (when quantum process tomography is infeasible), our method should be immediately useful for evaluating the degree of control that is achievable in any prototype quantum processing device. By varying over different experimental arrangements and error-correction strategies a...
Scalable noise estimation with random unitary operators
Energy Technology Data Exchange (ETDEWEB)
Emerson, Joseph [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); Alicki, Robert [Institute of Theoretical Physics and Astrophysics, University of Gdansk, Wita Stwosza 57, PL 80-952 Gdansk (Poland); Zyczkowski, Karol [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada)
2005-10-01
We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method is based on the motion reversal of random unitary operators. In the simplest case our method enables direct estimation of the average gate fidelity. The more general fidelities are characterized by a universal exponential rate of fidelity loss. In all cases the measurable fidelity decrease is directly related to the strength of the noise affecting the implementation, quantified by the trace of the superoperator describing the non-unitary dynamics. While the scalability of our stochastic protocol makes it most relevant in large Hilbert spaces (when quantum process tomography is infeasible), our method should be immediately useful for evaluating the degree of control that is achievable in any prototype quantum processing device. By varying over different experimental arrangements and error-correction strategies, additional information about the noise can be determined.
14 CFR 23.939 - Powerplant operating characteristics.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Powerplant operating characteristics. 23... General § 23.939 Powerplant operating characteristics. (a) Turbine engine powerplant operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall,...
Power system operations: State estimation distributed processing
Ebrahimian, Mohammad Reza
We present an application of a robust and fast parallel algorithm to power system state estimation with minimal amount of modifications to existing state estimators presently in place using the Auxiliary Problem Principle. We demonstrate its effectiveness on IEEE test systems, the Electric Reliability Counsel of Texas (ERCOT), and the Southwest Power Pool (SPP) systems. Since state estimation formulation may lead to an ill-conditioned system, we provide analytical explanations of the effects of mixtures of measurements on the condition of the state estimation information matrix. We demonstrate the closeness of the analytical equations to condition of several test case systems including IEEE RTS-96 and IEEE 118 bus systems. The research on the condition of the state estimation problem covers the centralized as well as distributed state estimation.
Operation characteristics of a multiple type MCFC
Energy Technology Data Exchange (ETDEWEB)
Kuroe, S.; Kamo, T. [Hitachi Research Lab., Hitachi, Ltd., Ibaraki-ken (Japan); Fujimura, H.; Kahara, T. [Hitachi, Ltd., Ibaraki-ken (Japan)
1996-12-31
Multiple type structure of MCFC of which the separator of the cell is divided by four element cells has been studied. For the stable operation of this type cell, the effect of gas flow rate and temperature distribution on the cell voltage should be clear. In order to clarify these characteristics, a small sized mimic model has been made and tested. The flow rate distribution for the four element cells were varied and cell voltage and temperature distribution were measured for each cell. The decrease in cell voltage and the increase in maximum temperature became remarkable when the apparent utilization factor for one element cell became over 100%. The calculated results agreed fairly good with test results.
ESTIMATES FOR THE MAXIMAL MULTILINEAR SINGULAR INTEGRAL OPERATORS
Institute of Scientific and Technical Information of China (English)
Yulan Jiao
2010-01-01
In this paper,some mapping properties are considered for the maximal multilinear singular integral operator whose kernel satisfies certain minimum regularity condition.It is proved that certain uniform local estimate for doubly truncated operators implies the LP(Rn)(1
estimate for the corresponding maximal operator.
Operational Characteristics of Para-transit Modes in Akure, Nigeria ...
African Journals Online (AJOL)
Operational Characteristics of Para-transit Modes in Akure, Nigeria. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... Data on the cogent indices of metering operations, attributes of operators and patrons of para-transit modes were ...
Weighted BMO Estimates for Toeplitz Operators on Weighted Lebesgue Spaces
Directory of Open Access Journals (Sweden)
Yan Lin
2015-01-01
Full Text Available The authors establish the weighted BMO estimates for a class of Toeplitz operators related to strongly singular Calderón-Zygmund operators on weighted Lebesgue spaces. Moreover, the corresponding result for the Toeplitz operators related to classical Calderón-Zygmund operators can be deduced.
2010-01-01
... consumption, estimated annual operating cost, and energy efficiency rating, and of water use rate. 305.5... RULE CONCERNING DISCLOSURES REGARDING ENERGY CONSUMPTION AND WATER USE OF CERTAIN HOME APPLIANCES AND... § 305.5 Determinations of estimated annual energy consumption, estimated annual operating cost, and...
Spectral estimates for periodic fourth order operators
Badanin, Andrey
2008-01-01
We consider the operator $H={d^4dt^4}+{ddt}p{ddt}+q$ with 1-periodic coefficients on the real line. The spectrum of $H$ is absolutely continuous and consists of intervals separated by gaps. We describe the spectrum of this operator in terms of the Lyapunov function, which is analytic on a two-sheeted Riemann surface. On each sheet the Lyapunov function has the standard properties of the Lyapunov function for the scalar case. We describe the spectrum of $H$ in terms of periodic, antiperiodic eigenvalues, and so-called resonances. We prove that 1) the spectrum of $H$ at high energy has multiplicity two, 2) the asymptotics of the periodic, antiperiodic eigenvalues and of the resonances are determined at high energy, 3) for some specific $p$ the spectrum of $H$ has an infinite number of gaps, 4) the spectrum of $H$ has small spectral band (near the beginner of the spectrum) with multiplicity 4 and its asymptotics are determined as $p\\to 0, q=0$.
Characteristics of Managing Operational Banking Risk
Directory of Open Access Journals (Sweden)
Adela Socol
2008-12-01
Full Text Available The objective of this paper is to provide a global perspective of the operational risk from a banking societies’ viewpoint. We describe the main regulations and settlements in the field and examine the various approaches of the operational banking risk. The paper presents the need of banks to managing operational risk. We study comparatively for a banking society the capital charge for covering the operational risk under the basic indicator approach and under the standardized approach. We present a case study of implementing current capital requirements at the level of a Romanian banking society. From the theoretical approach and from the description of quantifying of operational banking risk, the results of this study insist on the importance of measuring of operational banking risk and identifies major issues that need to be considered to improve the managing operational banking risk.
Oil development-operating cost estimates, 1955-85
Energy Technology Data Exchange (ETDEWEB)
Adelman, M.A.; Shahi, M.
1989-01-01
Few if any published oil production cost estimates can be verified as to method and basic data. Using US drilling costs and some assumptions explained in the text, this paper estimates development-operating costs in 41 oil-producing nations, from 1955 to 1985, from publicly available data on drilling. Estimation methods are described in detail so that anyone with access to better information on any item can substitute it to arrive at a better estimate.
Models for estimation of land remote sensing satellites operational efficiency
Kurenkov, Vladimir I.; Kucherov, Alexander S.
2017-01-01
The paper deals with the problem of estimation of land remote sensing satellites operational efficiency. Appropriate mathematical models have been developed. Some results obtained with the help of the software worked out in Delphi programming support environment are presented.
Estimation of pump operational state with model-based methods
Energy Technology Data Exchange (ETDEWEB)
Ahonen, Tero; Tamminen, Jussi; Ahola, Jero; Viholainen, Juha; Aranto, Niina [Institute of Energy Technology, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta (Finland); Kestilae, Juha [ABB Drives, P.O. Box 184, FI-00381 Helsinki (Finland)
2010-06-15
Pumps are widely used in industry, and they account for 20% of the industrial electricity consumption. Since the speed variation is often the most energy-efficient method to control the head and flow rate of a centrifugal pump, frequency converters are used with induction motor-driven pumps. Although a frequency converter can estimate the operational state of an induction motor without external measurements, the state of a centrifugal pump or other load machine is not typically considered. The pump is, however, usually controlled on the basis of the required flow rate or output pressure. As the pump operational state can be estimated with a general model having adjustable parameters, external flow rate or pressure measurements are not necessary to determine the pump flow rate or output pressure. Hence, external measurements could be replaced with an adjustable model for the pump that uses estimates of the motor operational state. Besides control purposes, modelling the pump operation can provide useful information for energy auditing and optimization purposes. In this paper, two model-based methods for pump operation estimation are presented. Factors affecting the accuracy of the estimation methods are analyzed. The applicability of the methods is verified by laboratory measurements and tests in two pilot installations. Test results indicate that the estimation methods can be applied to the analysis and control of pump operation. The accuracy of the methods is sufficient for auditing purposes, and the methods can inform the user if the pump is driven inefficiently. (author)
Estimating personalized diagnostic rules depending on individualized characteristics.
Liu, Ying; Wang, Yuanjia; Huang, Chaorui; Zeng, Donglin
2017-03-30
There is an increasing demand for personalization of disease screening based on assessment of patient risk and other characteristics. For example, in breast cancer screening, advanced imaging technologies have made it possible to move away from 'one-size-fits-all' screening guidelines to targeted risk-based screening for those who are in need. Because diagnostic performance of various imaging modalities may vary across subjects, applying the most accurate modality to the patients who would benefit the most requires personalized strategy. To address these needs, we propose novel machine learning methods to estimate personalized diagnostic rules for medical screening or diagnosis by maximizing a weighted combination of sensitivity and specificity across subgroups of subjects. We first develop methods that can be applied when competing modalities or screening strategies that are observed on the same subject (paired design). Next, we present methods for studies where not all subjects receive both modalities (unpaired design). We study theoretical properties including consistency and risk bound of the personalized diagnostic rules and conduct simulation studies to examine performance of the proposed methods. Lastly, we analyze data collected from a brain imaging study of Parkinson's disease using positron emission tomography and diffusion tensor imaging with paired and unpaired designs. Our results show that in some cases, a personalized modality assignment is estimated to improve empirical area under the receiver operating curve compared with a 'one-size-fits-all' assignment strategy. Copyright © 2016 John Wiley & Sons, Ltd.
ACCURATE ESTIMATES OF CHARACTERISTIC EXPONENTS FOR SECOND ORDER DIFFERENTIAL EQUATION
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
In this paper, a second order linear differential equation is considered, and an accurate estimate method of characteristic exponent for it is presented. Finally, we give some examples to verify the feasibility of our result.
Diffusion Estimation from Multiscale Data by Operator Eigenpairs
Crommelin, D.T.; Vanden-Eijnden, E.
2011-01-01
In this paper we present a new procedure for the estimation of diffusion processes from discretely sampled data. It is based on the close relation between eigenpairs of the diffusion operator L and those of the conditional expectation operator Pt, a relation stemming from the semigroup structure Pt
Performance of sampling methods to estimate log characteristics for wildlife.
Lisa J. Bate; Torolf R. Torgersen; Michael J. Wisdom; Edward O. Garton
2004-01-01
Accurate estimation of the characteristics of log resources, or coarse woody debris (CWD), is critical to effective management of wildlife and other forest resources. Despite the importance of logs as wildlife habitat, methods for sampling logs have traditionally focused on silvicultural and fire applications. These applications have emphasized estimates of log volume...
Two methods for estimating aeroelastic damping of operational wind turbine modes from experiments
DEFF Research Database (Denmark)
Hansen, Morten Hartvig; Thomsen, Kenneth; Fuglsang, Peter;
2006-01-01
on stochastic subspace identification, where a linear model of the turbine is estimated alone from measured response signals by assuming that the ambient excitation from turbulence is random in time and space. Although the assumption is not satisfied, this operational modal analysis method can handle......The theory and results of two experimental methods for estimating the modal damping of a wind turbine during operation are presented. Estimations of the aeroelastic damping of the operational turbine modes (including the effects of the aerodynamic forces) give a quantitative view of the stability...... characteristics of the turbine. In the first method the estimation of modal damping is based on the assumption that a turbine mode can be excited by a harmonic force at its natural frequency, whereby the decaying response after the end of excitation gives an estimate of the damping. Simulations and experiments...
Estimation of operative temperature in buildings using artificial neural networks
Energy Technology Data Exchange (ETDEWEB)
Soleimani-Mohseni, M.; Fahlen, P. [Department of Building Services Engineering, Chalmers University of Technology, Goeteborg (Sweden); Thomas, B. [Department of Signals and Systems, Chalmers University of Technology, Campus Lindholmen, Goeteborg (Sweden)
2006-07-01
In this article, the problem how to obtain models for estimation of the operative temperature in rooms and buildings is discussed. Identification experiments have been carried out in two different buildings and different linear and non-linear estimation models have been identified based on these experiments. For the buildings studied, it is shown that the operative temperature can be estimated fairly well by using variables, which are more easily measured, such as the indoor and outdoor temperatures, the electrical power use in the room, the wall temperatures, the ventilation flow rates and the time of day. It is also shown that non-linear artificial neural network models (ANN-models), in general, give better estimations than linear ARX-models. The most accurate estimation models were obtained using feed-forward ANN-models with one hidden layer of neurons and using Levenberg-Marquardt's training algorithms. In one of the buildings, it is shown that for non-linear models but not for linear, the estimations are improved much when using the time of day as an input signal. This shows that the time of day affects the operative temperature in a non-linear manner. (author)
Operational Characteristics of an Accelerator Driven Fissile Solution System
Energy Technology Data Exchange (ETDEWEB)
Kimpland, Robert Herbert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-11-28
Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the form of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems require the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a “generic” Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system
Estimation of fatigue characteristics of asphaltic mixes using simple tests
Medani, T.O.; Molenaar, A.A.A.
2000-01-01
A simplified procedure for estimation of fatigue characteristics of asphaltic mixes is presented. The procedure requires the determination of the so-called master curve (Le. the relationship between the mix stiffness, the loading time and the temperature), the asphalt properties and the mix
The Nevada railroad system: Physical, operational, and accident characteristics
Energy Technology Data Exchange (ETDEWEB)
NONE
1991-09-01
This report provides a description of the operational and physical characteristics of the Nevada railroad system. To understand the dynamics of the rail system, one must consider the system`s physical characteristics, routing, uses, interactions with other systems, and unique operational characteristics, if any. This report is presented in two parts. The first part is a narrative description of all mainlines and major branchlines of the Nevada railroad system. Each Nevada rail route is described, including the route`s physical characteristics, traffic type and volume, track conditions, and history. The second part of this study provides a more detailed analysis of Nevada railroad accident characteristics than was presented in the Preliminary Nevada Transportation Accident Characterization Study (DOE, 1990).
Therapy operating characteristic curves: tools for precision chemotherapy.
Barrett, Harrison H; Alberts, David S; Woolfenden, James M; Caucci, Luca; Hoppin, John W
2016-04-01
The therapy operating characteristic (TOC) curve, developed in the context of radiation therapy, is a plot of the probability of tumor control versus the probability of normal-tissue complications as the overall radiation dose level is varied, e.g., by varying the beam current in external-beam radiotherapy or the total injected activity in radionuclide therapy. This paper shows how TOC can be applied to chemotherapy with the administered drug dosage as the variable. The area under a TOC curve (AUTOC) can be used as a figure of merit for therapeutic efficacy, analogous to the area under an ROC curve (AUROC), which is a figure of merit for diagnostic efficacy. In radiation therapy, AUTOC can be computed for a single patient by using image data along with radiobiological models for tumor response and adverse side effects. The mathematical analogy between response of observers to images and the response of tumors to distributions of a chemotherapy drug is exploited to obtain linear discriminant functions from which AUTOC can be calculated. Methods for using mathematical models of drug delivery and tumor response with imaging data to estimate patient-specific parameters that are needed for calculation of AUTOC are outlined. The implications of this viewpoint for clinical trials are discussed.
AN ENDPOINT ESTIMATE FOR MAXIMAL MULTILINEAR SINGULAR INTEGRAL OPERATORS
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A weak type endpoint estimate for the maximal multilinear singular integral operator T*Af(x)=supε＞0|(f)(x-y)＞ε (Ω(x-y)/(|x-y|(n+1)))(A(x)-A(y)-▽A(y)(x-y))f(y)dy| is established, where Ω is homogeneous of degree zero, integrable on the unit sphere and has vanishing moment of order one, and A has derivatives of order one in BMO(Rn). A regularity condition on Ω which implies an LlogL type estimate of T*A is given.
ANALYSIS OF THE OPERATIONAL CHARACTERISTICS OF DIESEL-ELECTRIC LOCOMOTIVES
Directory of Open Access Journals (Sweden)
L. V. Ursulyak
2014-12-01
Full Text Available Purpose. To compare the operational characteristics of freight diesel-electric locomotives ER20CF and 2М62м, which are operated with Lithuanian Railways. Important problems on traction calculations are considered in this article. In this article the critical tasks of traction calculations are solved. It is the main computational tool in the rational functioning, planning and development of railways: determination of the estimated weight of the rolling stock, the diagrams construction of specific resultant forces of a train, the permitted speed definition of the train on the slopes, curves of train traffic construction on the section. Methodology. Using the rules and methods of traction calculations the analysis of the basic operational characteristics of the modernized freight diesel-electric locomotive 2М62m and freight passenger dual locomotive 2ER20CF was held. The maximum weight of the train set, the track structure on a high-speed ascent through the use of kinetic energy (with traction and without traction, technical speed, acceleration force and the value of the smallest radius curve are selected as controlled parameters. During the calculations it was considered that the trains were formed of a fully loaded four-axle gondola cars, model 112-119 (feature-606 with axle load of 23.5 t; the motion was carried out on the continuous welded rail track; the front of the train set is a dual locomotive 2ER20CF or two locomotive 2М62м. Longitudinal profile of the road on the route Vilnus–KlF was analyzed for the choice of theoretical rise. Inspection concerning the possibility of overcoming the high-speed rise was performed with an analytical method, based on the use of the kinetic energy accumulated by the overcoming of «light» elements of the profile. Findings. In the calculations, the maximum weight of the train set taking into account theoretical rise was analyzed. The inspection of the theoretical weight of the train set on a reliable
Blade Bearing Friction Estimation of Operating Wind Turbines
DEFF Research Database (Denmark)
Perisic, Nevena; Pedersen, Bo Juul; Kirkegaard, Poul Henning
2012-01-01
Blade root bearing on a wind turbine (WTG) enables pitching of blades for power control and rotor braking and is a WTG critical component. As the size of modern WTGs is constantly increasing, this leads to relatively less rigid bearings, more sensitive to deformations, thus WTG operational...... reliability can be increased by continuous monitoring of blade bearing. High blade bearing friction is undesirable, as it may be associated with excessive heating of the surfaces, damage and/or inefficient operation. Thus, continuous observation of bearing friction level is crucial for blade bearing health...... monitoring systems. A novel algorithm for online monitoring of bearing friction level is developed combining physical knowledge about pitch system dynamics with state estimator, i.e. observer theory and signal processing assuming realistic sensor availability. Results show estimation of bearing friction...
Estimation of fuel cell operating time for predictive maintenance strategies
Energy Technology Data Exchange (ETDEWEB)
Onanena, R. [FC LAB, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); FEMTO-ST (UMR CNRS 6174), ENISYS department, University of Franche-Comte (France); INRETS - LTN, ' ' Le Descartes 2' ' , 2 rue de la butte verte, 93166 Noisy-le-Grand Cedex (France); Oukhellou, L. [INRETS - LTN, ' ' Le Descartes 2' ' , 2 rue de la butte verte, 93166 Noisy-le-Grand Cedex (France); CERTES Universite Paris 12, 61 avenue du Gal. de Gaulle, 94100 Creteil (France); Candusso, D. [FC LAB, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); INRETS - LTN, ' ' Le Descartes 2' ' , 2 rue de la butte verte, 93166 Noisy-le-Grand Cedex (France); Same, A.; Aknin, P. [INRETS - LTN, ' ' Le Descartes 2' ' , 2 rue de la butte verte, 93166 Noisy-le-Grand Cedex (France); Hissel, D. [FC LAB, Techn' Hom, rue Thierry Mieg, 90010 Belfort Cedex (France); FEMTO-ST (UMR CNRS 6174), ENISYS department, University of Franche-Comte (France)
2010-08-15
Durability is one of the limiting factors for spreading and commercialization of fuel cell technology. That is why research to extend fuel cell durability is being conducted world wide. A pattern-recognition approach aiming to estimate fuel cell operating time based on electrochemical impedance spectroscopy measurements is presented here. It is based on extracting the features from the impedance spectra. For that purpose, two approaches have been investigated. In the first one, particular points of the spectrum are empirically extracted as features. In the second approach, a parametric modeling is performed to extract features from both the real and the imaginary parts of the impedance spectrum. In particular, a latent regression model is used to automatically split the spectrum into several segments that are approximated by polynomials. The number of segments is adjusted taking into account the a priori knowledge about the physical behavior of the fuel cell components. Then, a linear regression model using different subsets of extracted features is employed for an estimate of the fuel cell operating time. The effectiveness of the proposed approach is evaluated on an experimental dataset. Allowing the estimation of the fuel cell operating time, and consequently its remaining duration life, these results could lead to interesting perspectives for predictive fuel cells maintenance policy. (author)
Tool Wear Estimate in Milling Operation by FEM
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Many researches show that, in metal cutting process, tool wear rate depends on some cutting process parameters, such as temperature at tool face, contact pressure and relative sliding velocity at tool/chip and tool/workpiece interfaces. Finite element method(FEM) application enables the estimate of these parameters and the tool wear. A tool wear estimate program based on chip formation and heat transfer analysis is designed and compiled with Python to calculate the wear rate and volume, and update tool geometry according to the tool wear. The progressive flank and crater wears in milling operation are estimated by the program. The FEM code ABAQUS/Explicit and Standard are employed to analyze chip formation and heat transfer process.
Model calibration criteria for estimating ecological flow characteristics
Vis, Marc; Knight, Rodney; Poole, Sandra; Wolfe, William; Seibert, Jan; Breuer, Lutz; Kraft, Philipp
2016-01-01
Quantification of streamflow characteristics in ungauged catchments remains a challenge. Hydrological modeling is often used to derive flow time series and to calculate streamflow characteristics for subsequent applications that may differ from those envisioned by the modelers. While the estimation of model parameters for ungauged catchments is a challenging research task in itself, it is important to evaluate whether simulated time series preserve critical aspects of the streamflow hydrograph. To address this question, seven calibration objective functions were evaluated for their ability to preserve ecologically relevant streamflow characteristics of the average annual hydrograph using a runoff model, HBV-light, at 27 catchments in the southeastern United States. Calibration trials were repeated 100 times to reduce parameter uncertainty effects on the results, and 12 ecological flow characteristics were computed for comparison. Our results showed that the most suitable calibration strategy varied according to streamflow characteristic. Combined objective functions generally gave the best results, though a clear underprediction bias was observed. The occurrence of low prediction errors for certain combinations of objective function and flow characteristic suggests that (1) incorporating multiple ecological flow characteristics into a single objective function would increase model accuracy, potentially benefitting decision-making processes; and (2) there may be a need to have different objective functions available to address specific applications of the predicted time series.
Energy estimate for initial data on a characteristic cone
Choquet-Bruhat, Yvonne
2010-01-01
The Einstein equations in wave map gauge are a geometric second order system for a Lorentzian metric. To study existence of solutions of this hyperbolic quasi diagonal system with initial data on a characteristic cone which are not zero in a neighbourhood of the vertex one can appeal to theorems due to Cagnac and Dossa, proved for a scalar wave equation, for initial data in functional spaces relevant for their proofs. It is difficult to check that the initial data that we have constructed as solutions of the Einstein wave-map gauge constraints satisfy the more general of the Cagnac-Dossa hypotheses which uses weighted energy estimates. In this paper we start a new study of energy estimates using on the cone coordinates adapted to its null structure which are precisely the coordinates used to solve the constraints, following work of Rendall who considered the Cauchy problem for Einstein equations with data on two intersecting characteristic surfaces.
Li, Qiang; Wang, Zhongyu; Wang, Zhuoran; Yan, Hu
2015-06-01
A shock tube is usually used to excite the dynamic characteristics of the pressure sensor used in an aircraft. This paper proposes a novel estimation method for determining the dynamic characteristic parameters of the pressure sensor. A preprocessing operation based on Grey Model [GM(1,1)] and bootstrap method (BM) is employed to analyze the output of a calibrated pressure sensor under step excitation. Three sequences, which include the estimated value sequence, upper boundary, and lower boundary, are obtained. The processing methods on filtering and modeling are used to explore the three sequences independently. The optimal estimated, upper boundary, and lower boundary models are then established. The three models are solved, and a group of dynamic characteristic parameters corresponding to the estimated intervals are obtained. A shock tube calibration test consisting of two experiments is performed to validate the performance of the proposed method. The results show that the relative errors of the dynamic characteristic parameters of time and frequency domains do not exceed 9% and 10%, respectively. Moreover, the nominal and estimated values of the parameters fall into the estimated intervals limited by the upper and lower values.
METRIC TESTS CHARACTERISTIC FOR ESTIMATING JUMPING FOR VOLLEYBALL PLAYERS
Directory of Open Access Journals (Sweden)
Toplica Stojanović
2008-08-01
Full Text Available With goal to establish metric tests characteristics for estimating jumping for volleyball players, it was organized a pilot research on pattern of 23 volleyball players from cadet team and 23 students from high-school. For needs of this research four tests are valid for estimation, jump in block with left and right leg and jump in spike with left and right leg. Each test has been taken three times, so that we could with test-re test method determine their reliability, and with factor analysis their validity. Data were processed by multivariate analysis (item analysis, factor analysis from statistical package „Statistica 6.0 for windows“. On the results of research and discussion we can say that the tests had high coefficient of reliability, as well as factor validity, and these tests can be used to estimate jumping for volleyball players.
Application of Bayesian Networks for Estimation of Individual Psychological Characteristics
Litvinenko, Alexander
2017-07-19
In this paper we apply Bayesian networks for developing more accurate final overall estimations of psychological characteristics of an individual, based on psychological test results. Psychological tests which identify how much an individual possesses a certain factor are very popular and quite common in the modern world. We call this value for a given factor -- the final overall estimation. Examples of factors could be stress resistance, the readiness to take a risk, the ability to concentrate on certain complicated work and many others. An accurate qualitative and comprehensive assessment of human potential is one of the most important challenges in any company or collective. The most common way of studying psychological characteristics of each single person is testing. Psychologists and sociologists are constantly working on improvement of the quality of their tests. Despite serious work, done by psychologists, the questions in tests often do not produce enough feedback due to the use of relatively poor estimation systems. The overall estimation is usually based on personal experiences and the subjective perception of a psychologist or a group of psychologists about the investigated psychological personality factors.
Estimated water requirements for gold heap-leach operations
Bleiwas, Donald I.
2012-01-01
This report provides a perspective on the amount of water necessary for conventional gold heap-leach operations. Water is required for drilling and dust suppression during mining, for agglomeration and as leachate during ore processing, to support the workforce (requires water in potable form and for sanitation), for minesite reclamation, and to compensate for water lost to evaporation and leakage. Maintaining an adequate water balance is especially critical in areas where surface and groundwater are difficult to acquire because of unfavorable climatic conditions [arid conditions and (or) a high evaporation rate]; where there is competition with other uses, such as for agriculture, industry, and use by municipalities; and where compliance with regulatory requirements may restrict water usage. Estimating the water consumption of heap-leach operations requires an understanding of the heap-leach process itself. The task is fairly complex because, although they all share some common features, each gold heap-leach operation is unique. Also, estimating the water consumption requires a synthesis of several fields of science, including chemistry, ecology, geology, hydrology, and meteorology, as well as consideration of economic factors.
OPERATION MODES AND CHARACTERISTICS OF PLASMA DIPOLE ANTENNA
Directory of Open Access Journals (Sweden)
Nikolay Nikolaevich Bogachev
2014-02-01
Full Text Available Existence modes of surface electromagnetic wave on a plasma cylinder, operating modes and characteristics of the plasma antenna were studied in this paper. Solutions of the dispersion equation of surface wave were obtained for a plasma cylinder with finite radius for different plasma density values. Operation modes of the plasma asymmetric dipole antenna with finite length and radius were researched by numerical simulation. The electric field distributions of the plasma antenna in near antenna field and the radiation pattern were obtained. These characteristics were compared to characteristics of the similar metal antenna. Numerical models verification was carried out by comparing of the counted and measured metal antenna radiation patterns.
49 CFR 234.205 - Operating characteristics of warning system apparatus.
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Operating characteristics of warning system... characteristics of warning system apparatus. Operating characteristics of electromagnetic, electronic, or... limits within which the system is designed to operate....
Behaviour characteristics estimation tool of genetic distance between sheep breeds
Directory of Open Access Journals (Sweden)
Eko Handiwirawan
2014-12-01
Full Text Available Information on the estimation of genetic distances and differentiation among sheep breeds are needed in crossing and conservation programs. This research aims to study of utilizing behaviour characteristic variables to differentiate and estimate genetic distance between the sheep breeds. The study was conducted at Cilebut and Bogor Animal House of Indonesian Research Institute for Animal Production. Five sheep breeds used were Barbados Black Belly Cross (BC, Garut Composite (KG, Garut Local (LG, Sumatera Composite (KS and St. Croix Cross (SC, with total sample of 50 heads. A total of 10 variables of behavior traits were observed in this study. Analysis of variances and significance tests were applied to compare between sheep breeds and performed for all of behavior traits using PROC GLM of SAS Program ver. 9.0. PROC CANDISC was used for canonical discriminant analyses, the hierarchical clustering was performed using the PROC CLUSTER by Average Linkage method (Unweighted Pair-Group Method Using Arithmetic Averages, UPGMA, and the dendogram for the five sheep breeds was described using PROC TREE. The differentiator variables for the behavior traits were standing and feeding duration. The canonical plotting based on behavioral characteristics could differentiate BC, KS and LG (with KG and SC sheeps. Estimation of genetic distance based on the behavior traits is less accurate for grouping of sheep breeds.
Estimation of Anonymous Email Network Characteristics through Statistical Disclosure Attacks
Portela, Javier; García Villalba, Luis Javier; Silva Trujillo, Alejandra Guadalupe; Sandoval Orozco, Ana Lucila; Kim, Tai-Hoon
2016-01-01
Social network analysis aims to obtain relational data from social systems to identify leaders, roles, and communities in order to model profiles or predict a specific behavior in users’ network. Preserving anonymity in social networks is a subject of major concern. Anonymity can be compromised by disclosing senders’ or receivers’ identity, message content, or sender-receiver relationships. Under strongly incomplete information, a statistical disclosure attack is used to estimate the network and node characteristics such as centrality and clustering measures, degree distribution, and small-world-ness. A database of email networks in 29 university faculties is used to study the method. A research on the small-world-ness and Power law characteristics of these email networks is also developed, helping to understand the behavior of small email networks. PMID:27809275
Simplified models for estimating isothermal operating characteristics of food extruders.
Levine, L; Rockwood, J
1985-09-01
A model of isothermal food extruder performance is described. Inferences about alternative extruder screw designs and their performance are drawn from the model. The model suggests that thread depth or diameter compression screws are superior in performance to a pitch compression screw. The advantage gained from using diameter compression screws is paid for with significantly higher rates of energy dissipation. The use of the model to characterize screws having both a compression zone and metering zone is described.
Design and Operational Characteristics of the Shuttle Coherent Wind Lidar
Amzajerdian, Farzin; Spiers, Gary D.; Peters, Bruce R.; Li, Ye; Blackwell, Timothy S.; Geary, Joseph M.
1998-01-01
NOAA has identified the measurement of atmospheric wind velocities as one of the key unmet data sets for its next generation of sensing platforms. The merits of coherent lidars for the measurement of atmospheric winds from space platforms have been widely recognized; however, it is only recently that several key technologies have advanced to a point where a compact, high fidelity system could be created. Advances have been made in the areas of the diode-pumped, eye-safe, solid state lasers and room temperature, wide bandwidth, semiconductor detectors operating in the near-infrared region. These new lasers can be integrated into efficient and compact optical systems creating new possibilities for the development of low-cost, reliable, and compact coherent lidar systems for wind measurements. Over the past five years, the University of Alabama in Huntsville (UAH) has been working toward further advancing the solid state coherent lidar technology for the measurement of atmospheric winds from space. As part of this effort, UAH had established the design characteristics and defined the expected performance for three different proposed space-based instruments: a technology demonstrator, an operational prototype, and a 7-year lifetime operational instrument. SPARCLE is an ambitious project that is intended to evaluate the suitability of coherent lidar for wind measurements, demonstrate the maturity of the technology for space application, and provide a useable data set for model development and validation. This paper describes the SPARCLE instrument's major physical and environmental design constraints, optical and mechanical designs, and its operational characteristics.
Estimation of the characteristic energy of electron precipitation
Directory of Open Access Journals (Sweden)
C. F. del Pozo
Full Text Available Data from simultaneous observations (on 13 February 1996, 9 November 1998, and 12 February 1999 with the IRIS, DASI and EISCAT systems are employed in the study of the energy distribution of the electron precipitation during substorm activity. The estimation of the characteristic energy of the electron precipitation over the common field of view of IRIS and DASI is discussed. In particular, we look closely at the physical basis of the correspondence between the characteristic energy, the flux-averaged energy, as defined below, and the logarithm of the ratio of the green-light intensity to the square of absorption. This study expands and corrects results presented in the paper by Kosch et al. (2001. It is noticed, moreover, that acceleration associated with diffusion processes in the magnetosphere long before precipitation may be controlling the shape of the energy spectrum. We propose and test a "mixed" distribution for the energy-flux spectrum, exponential at the lower energies and Maxwellian or modified power-law at the higher energies, with a threshold energy separating these two regimes. The energy-flux spectrum at Tromsø, in the 1–320 keV range, is derived from EISCAT electron density profiles in the 70–140 km altitude range and is applied in the "calibration" of the optical intensity and absorption distributions, in order to extrapolate the flux and characteristic energy maps.
Key words. Ionosphere (auroral ionosphere; particle precipitation; particle acceleration
Demirjian approach of dental age estimation: Abridged for operator ease
Directory of Open Access Journals (Sweden)
Vanshika Jain
2016-01-01
Full Text Available Background: Present times have seen an alarming increase in incidence of crimes by juveniles and of mass destruction that Highlight the preponderance of individual age estimation. Of the numerous techniques employed for age assessment, dental age estimation (DAE and its correlation with chronological age (CA have been of great significance in the recent past. Demirjian system, considered as gold standard in DAE is a simple and convenient method for DAE, though,, although, referring to multiple tables make it cumbersome and less eco friendly due to excessive paper load. Aim: The present study was aimed to develop a comprehensive chart (DAEcc inclusive of all Demirjian tables and developmental stages of teeth and also to as well as to test the operator ease of 50 undergraduate dental students in performing DAE using this chart. Materials and Methods: The study was performed in two stages, wherein the first stage was aimed at formulation of the comprehensive chart (DAECC which included pictorial representation of calcification stages, the Federation Dentaire Internationale notation of the teeth, and the corresponding scores for each stage with a concluding column at the end to enter the total score. The second stage assessed the applicability of the ease of DAE by DAECC, whereby fifty 2nd year BDS students were asked to trace the calcification stages of the seven permanent left mandibular teeth on a panorex, identify the correct stage, assign the corresponding score, and to calculate the total score for subsequent dental age assessment. Results and Conclusions: showed that average time taken by the students for tracing seven mandibular teeth was 5 min and for assessment of dental age was 7 min. The total time taken for DAE was approximately 12 min, thus making the procedure less time consuming. Hence, this study proposes the use of DAEcc for age estimation due to ease in comprehension and execution of Demirjian system.
Demirjian approach of dental age estimation: Abridged for operator ease
Jain, Vanshika; Kapoor, Priyanka; Miglani, Ragini
2016-01-01
Background: Present times have seen an alarming increase in incidence of crimes by juveniles and of mass destruction that Highlight the preponderance of individual age estimation. Of the numerous techniques employed for age assessment, dental age estimation (DAE) and its correlation with chronological age (CA) have been of great significance in the recent past. Demirjian system, considered as gold standard in DAE is a simple and convenient method for DAE, though,, although, referring to multiple tables make it cumbersome and less eco friendly due to excessive paper load. Aim: The present study was aimed to develop a comprehensive chart (DAEcc) inclusive of all Demirjian tables and developmental stages of teeth and also to as well as to test the operator ease of 50 undergraduate dental students in performing DAE using this chart. Materials and Methods: The study was performed in two stages, wherein the first stage was aimed at formulation of the comprehensive chart (DAECC) which included pictorial representation of calcification stages, the Federation Dentaire Internationale notation of the teeth, and the corresponding scores for each stage with a concluding column at the end to enter the total score. The second stage assessed the applicability of the ease of DAE by DAECC, whereby fifty 2nd year BDS students were asked to trace the calcification stages of the seven permanent left mandibular teeth on a panorex, identify the correct stage, assign the corresponding score, and to calculate the total score for subsequent dental age assessment. Results and Conclusions: showed that average time taken by the students for tracing seven mandibular teeth was 5 min and for assessment of dental age was 7 min. The total time taken for DAE was approximately 12 min, thus making the procedure less time consuming. Hence, this study proposes the use of DAEcc for age estimation due to ease in comprehension and execution of Demirjian system. PMID:28123280
Classification of operational characteristics of commercial cup-anemometers
Energy Technology Data Exchange (ETDEWEB)
Friis Pedersen, T.; Schmidt Paulsen, U. [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)
1999-03-01
The present classification of cup-anemometers is based on a procedure for classification of operational characteristics of cup-anemometers that was proposed at the EWEC `97 conference in Dublin 1997. Three definitions of wind speed are considered. The average longitudinal wind speed (ID), the average horizontal wind speed (2D) and the average vector wind speed (3D). The classification is provided in these terms, and additionally, the turbulence intensities, which are defined from the same wind speed definitions. The commercial cup-anemometers have all been calibrated in wind tunnel for the normal calibrations and angular characteristics. Friction was measured by blywheel testing, where the surrounding temperatures were varied over a wide range. The characteristics of the cup-anemometers have been fitted to the heuristic dynamic model, and the response has been calculated in time domain for prescribed ranges of external operational conditions. The results are presented in ranges of maximum deviations of `measured` average wind speed. For each definition of wind speed and turbulence intensity, the cup-anemometers are ranked according to the most precise instrument. Finally, the most important systematic error sources are commented. (au)
Spectral Characteristics of the Unitary Critical Almost-Mathieu Operator
Fillman, Jake; Ong, Darren C.; Zhang, Zhenghe
2016-10-01
We discuss spectral characteristics of a one-dimensional quantum walk whose coins are distributed quasi-periodically. The unitary update rule of this quantum walk shares many spectral characteristics with the critical Almost-Mathieu Operator; however, it possesses a feature not present in the Almost-Mathieu Operator, namely singularity of the associated cocycles (this feature is, however, present in the so-called Extended Harper's Model). We show that this operator has empty absolutely continuous spectrum and that the Lyapunov exponent vanishes on the spectrum; hence, this model exhibits Cantor spectrum of zero Lebesgue measure for all irrational frequencies and arbitrary phase, which in physics is known as Hofstadter's butterfly. In fact, we will show something stronger, namely, that all spectral parameters in the spectrum are of critical type, in the language of Avila's global theory of analytic quasiperiodic cocycles. We further prove that it has empty point spectrum for each irrational frequency and away from a frequency-dependent set of phases having Lebesgue measure zero. The key ingredients in our proofs are an adaptation of Avila's Global Theory to the present setting, self-duality via the Fourier transform, and a Johnson-type theorem for singular dynamically defined CMV matrices which characterizes their spectra as the set of spectral parameters at which the associated cocycles fail to admit a dominated splitting.
Weak estimates for commutators of fractional integral operators
Institute of Scientific and Technical Information of China (English)
DING; Yong
2001-01-01
［1］Stein,E.M.,Singular Integrals and Differentiability Properties of Functions,Princeton:Princeton University Press,1970.［2］Muckenhoupt,B.,Wheeden,R.L.,Weighted norm inequalities for fractional integrals,Trans.Amer.Math.Soc.,1974,192:261-274.［3］Taibleson,M.H.,Weiss,G.,The molecular characterization of certain Hardy spaces,Astérisque,1980,77:67-149.［4］Chanillo,S.,Watson,D.K.,Wheeden,R.L.,Some integral and maximal operators related to starlike sets,Studia Math.,1993,107:223-255.［5］Ding,Y.,Lu,S.Z.,Weighted norm inequalities for fractional integral operators with rough kernel,Canad.J.Math.,1998,50:29-39.［6］Ding,Y.,Weak type bounds for a class of rough operators with power weights,Proc.Amer.Math.Soc.,1997,125:2939-2942.［7］Chanillo,S.,A note on commutators,Indiana Univ.Math.J.,1982,31:7-16.［8］Ding,Y.,Lu,S.Z.,Higher order commutators for a class of rough operators,Ark.Mat.,1999,37:33-44.［9］Pérez,C., Endpoint estimates for commutators of singular integral operators,J.Funct.Anal.,1995,128:163-185.［10］Rao,M.M.,Ren,Z.D.,Theorey of Orlicz Spaces,New York:Marcel Dekker,1991.［11］Fefferman,C.,Stein,E.M.,Hp spaces of several variables,Acta Math.,1972,129:137-193.［12］Garcia-Cuerva,J.,Rubio de Francia,J.L.,Weighted Norm Inequalities and Related Topics, Amsterdam:North-Holland,1985.［13］Adams,D.R.,A note on Riesz potentials,Duke Math.J.,1975,42:765-778.［14］Stein,E.M.,Note on the class Llog L,Studia Math.,1969,32:305-310.［15］Pérez,C.,Weighted norm inequalities for singular integral operators,J.London Math.Soc.,1994,49:296-308.［16］Stein,E.M.,Harmonic Analysis:Real-Variable Methods,Orthogonality,and Oscillatory Integrals,Princeton:Princeton University Press,1993.［17］Pérez,C.,On sufficient conditions for the boundedness of the Hardy-Littlewood maximal operator between weighted Lp-spaces with different weights,Proc.London Math.Soc.,1995,71:135-157.［18］Garcia-Cuerva,J.,Harboure,E.,Segovia,C.et al.,Weighted norm
The effects of criterion variability on relative operating characteristics
Energy Technology Data Exchange (ETDEWEB)
Brown, W.S. [Brookhaven Natl. Lab., Bldg. 130, Upton, NY 11973-5000 (United States); Emmerich, D.S. [State Univ. of New York at Stony Brook, Stony Brook, NY 11974 (United States)
1995-05-01
The form of the relative operating characteristic (ROC) describing auditory detection typically differs from that expected based on the assumption that the observer`s responses reflect underlying distributions that are normal and of equal variance [e.g., Green and Swets, {ital Signal} {ital Detection} {ital Theory} {ital and} {ital Psychophysics}]. Specifically, it is found that binormal ROCs often have slopes less than one, and are not strictly linear [Watson {ital et} {ital al}., 283--288 (1964)]. It has been suggested that nonlinear binormal ROCs may be the result of extreme criteria being more variable than those more centrally positioned [Emmerich and Binder, J. Acoust. Soc. Am. Suppl. 1 {bold 65}, S59 (1979)]. The forms of rating ROCs obtained in an experiment designed to reveal the effects of such variability were consistent with the proposition that criteria associated with ``no`` responses are more variable than those associated with ``yes`` responses. Criterion operating characteristics [Wickelgren, J. Math. Psychol. {bold 5}, 102--122], which reflect the relative locations and variances of the boundaries of confidence categories, favored the same interpretation. It is concluded that the variability of criteria defining categories of rated confidence is sizable and not necessarily constant across criteria, and that such variability significantly influences the forms of empirical ROCs determined using confidence ratings in auditory signal detection.
Human dynamics scaling characteristics for aerial inbound logistics operation
Wang, Qing; Guo, Jin-Li
2010-05-01
In recent years, the study of power-law scaling characteristics of real-life networks has attracted much interest from scholars; it deviates from the Poisson process. In this paper, we take the whole process of aerial inbound operation in a logistics company as the empirical object. The main aim of this work is to study the statistical scaling characteristics of the task-restricted work patterns. We found that the statistical variables have the scaling characteristics of unimodal distribution with a power-law tail in five statistical distributions - that is to say, there obviously exists a peak in each distribution, the shape of the left part closes to a Poisson distribution, and the right part has a heavy-tailed scaling statistics. Furthermore, to our surprise, there is only one distribution where the right parts can be approximated by the power-law form with exponent α=1.50. Others are bigger than 1.50 (three of four are about 2.50, one of four is about 3.00). We then obtain two inferences based on these empirical results: first, the human behaviors probably both close to the Poisson statistics and power-law distributions on certain levels, and the human-computer interaction behaviors may be the most common in the logistics operational areas, even in the whole task-restricted work pattern areas. Second, the hypothesis in Vázquez et al. (2006) [A. Vázquez, J. G. Oliveira, Z. Dezsö, K.-I. Goh, I. Kondor, A.-L. Barabási. Modeling burst and heavy tails in human dynamics, Phys. Rev. E 73 (2006) 036127] is probably not sufficient; it claimed that human dynamics can be classified as two discrete university classes. There may be a new human dynamics mechanism that is different from the classical Barabási models.
Triebel–Lizorkin Space Estimates for Multilinear Operators of Sublinear Operators
Indian Academy of Sciences (India)
Liu Lanzhe
2003-11-01
In this paper, we obtain the continuity for some multilinear operators related to certain non-convolution operators on the Triebel–Lizorkin space. The operators include Littlewood–Paley operator and Marcinkiewicz operator.
Janes, Holly; Pepe, Margaret S
2009-06-01
Recent scientific and technological innovations have produced an abundance of potential markers that are being investigated for their use in disease screening and diagnosis. In evaluating these markers, it is often necessary to account for covariates associated with the marker of interest. Covariates may include subject characteristics, expertise of the test operator, test procedures or aspects of specimen handling. In this paper, we propose the covariate-adjusted receiver operating characteristic curve, a measure of covariate-adjusted classification accuracy. Nonparametric and semiparametric estimators are proposed, asymptotic distribution theory is provided and finite sample performance is investigated. For illustration we characterize the age-adjusted discriminatory accuracy of prostate-specific antigen as a biomarker for prostate cancer.
Energy Technology Data Exchange (ETDEWEB)
1978-01-01
A methodology was developed by which the operating cost associated with variations in aircraft design and technology characteristics can be assessed. This methodology addresses aircraft related operating cost elements and is based on an in-depth examination of airline operating experiences and relevant operating data. The assessment method produces a base line estimate of the operating cost elements relating to such design specification features as seat capacity, avionic equipment, design range, and design definition features such as maximum takeoff gross weight, and number of engines. Means for determining the deviations from this base line of the design or technological difference at the specific ATA System level are provided. The methodology was applied to assess the operating cost of one potential future advanced technology transport aircraft. An analysis was included to show the relative sensitivity of the operating cost to design parameters. Areas of potential future research on operating cost related technologies are identified.
Man-Vehicle Systems Research Facility - Design and operating characteristics
Shiner, Robert J.; Sullivan, Barry T.
1992-01-01
This paper describes the full-mission flight simulation facility at the NASA Ames Research Center. The Man-Vehicle Systems Research Facility (MVSRF) supports aeronautical human factors research and consists of two full-mission flight simulators and an air-traffic-control simulator. The facility is used for a broad range of human factors research in both conventional and advanced aviation systems. The objectives of the research are to improve the understanding of the causes and effects of human errors in aviation operations, and to limit their occurrence. The facility is used to: (1) develop fundamental analytical expressions of the functional performance characteristics of aircraft flight crews; (2) formulate principles and design criteria for aviation environments; (3) evaluate the integration of subsystems in contemporary flight and air traffic control scenarios; and (4) develop training and simulation technologies.
A unified discharge voltage characteristic for VRLA battery capacity and reserve time estimation
Energy Technology Data Exchange (ETDEWEB)
Pascoe, P.E.; Anbuky, A.H. [Invensys Energy Systems NZ Limited, Christchurch (New Zealand)
2004-01-01
Determining the capacity and discharge reserve time of a valve regulated lead acid battery is a highly non-trivial task. This is due to the dependence of the capacity and discharge reserve time on the discharge operating conditions as well as the battery condition. Operating conditions include discharge rate, ambient temperature and initial state of charge (SOC), while battery conditions include battery state of health and battery type. A simple approach is presented for estimating the SOC and discharge reserve time throughout a discharge. In addition, an estimation of capacity can be made at the completion of a shallow discharge. The approach employs a unified discharge characteristic that is shown to be robust to variations in operating conditions as well as battery condition. The approach provides a good degree of accuracy without the cost of complexity. Results are presented that demonstrate the estimation of the SOC to be well within 10% throughout the discharge and the reserve time (and capacity) to be within 10% from the early stages of the discharge. (author)
Lim, Tau Meng; Cheng, Shanbao; Chua, Leok Poh
2009-07-01
Axial flow blood pumps are generally smaller as compared to centrifugal pumps. This is very beneficial because they can provide better anatomical fit in the chest cavity, as well as lower the risk of infection. This article discusses the design, levitated responses, and parameter estimation of the dynamic characteristics of a compact hybrid magnetic bearing (HMB) system for axial flow blood pump applications. The rotor/impeller of the pump is driven by a three-phase permanent magnet brushless and sensorless motor. It is levitated by two HMBs at both ends in five degree of freedom with proportional-integral-derivative controllers, among which four radial directions are actively controlled and one axial direction is passively controlled. The frequency domain parameter estimation technique with statistical analysis is adopted to validate the stiffness and damping coefficients of the HMB system. A specially designed test rig facilitated the estimation of the bearing's coefficients in air-in both the radial and axial directions. Experimental estimation showed that the dynamic characteristics of the HMB system are dominated by the frequency-dependent stiffness coefficients. By injecting a multifrequency excitation force signal onto the rotor through the HMBs, it is noticed in the experimental results the maximum displacement linear operating range is 20% of the static eccentricity with respect to the rotor and stator gap clearance. The actuator gain was also successfully calibrated and may potentially extend the parameter estimation technique developed in the study of identification and monitoring of the pump's dynamic properties under normal operating conditions with fluid.
Ram accelerator operating characteristics at elevated fill pressures
Energy Technology Data Exchange (ETDEWEB)
Bundy, C.; Knowlen, C.; Bruckner, A.P. [Washington Univ., Seattle, WA (United States). Aerospace and Energetics Research Program
2000-11-01
An experimental investigation of the starting and operational characteristics of a 38-mm bore ram accelerator with propellant fill pressures greater than 5 MPa is in progress. Successful starts with 60 - 124 gm projectiles have been achieved using methane/oxygen/nitrogen propellants at fill pressures ranging from 6 to 15 MPa. At fill pressures of 8.5 MPa and above, it was found that projectiles having the nominal throat diameter (29 mm) required a minimum entrance velocity of 1250 m/s, which is about 100 m/s faster than the minimum needed to successfully start the ram accelerator at fill pressures below 7.5 MPa. Projectiles with a reduced throat diameter (25 mm) and a solid magnesium nose cone were successfully started at fill pressures up to 15 MPa with entrance velocities around 1300 m/s. The average accelerations achieved using high pressure stages were in general less than predicted for thermally choked operation by the Boltzmann equation of state. (orig.)
The Wegner Estimate and the Integrated Density of States for some Random Operators
Indian Academy of Sciences (India)
J M Combes; P D Hislop; Frédéric Klopp; Shu Nakamura
2002-02-01
The integrated density of states (IDS) for random operators is an important function describing many physical characteristics of a random system. Properties of the IDS are derived from the Wegner estimate that describes the influence of finite-volume perturbations on a background system. In this paper, we present a simple proof of the Wegner estimate applicable to a wide variety of random perturbations of deterministic background operators. The proof yields the correct volume dependence of the upper bound. This implies the local Hölder continuity of the integrated density of states at energies in the unperturbed spectral gap. The proof depends on the -theory of the spectral shift function (SSF), for ≥ 1, applicable to pairs of self-adjoint operators whose difference is in the trace ideal $\\mathcal{I}_p$, for 0 < ≤ 1. We present this and other results on the SSF due to other authors. Under an additional condition of the single-site potential, local Hölder continuity is proved at all energies. Finally, we present extensions of this work to random potentials with nonsign definite single-site potentials.
Goldstein, Arthur W; Alpert, Sumner; Beede, William; Kovach, Karl
1949-01-01
In order to understand the operation and the interaction of jet-engine components during engine operation and to determine how component characteristics may be used to compute engine performance, a method to analyze and to estimate performance of such engines was devised and applied to the study of the characteristics of a research turbojet engine built for this investigation. An attempt was made to correlate turbine performance obtained from engine experiments with that obtained by the simpler procedure of separately calibrating the turbine with cold air as a driving fluid in order to investigate the applicability of component calibration. The system of analysis was also applied to prediction of the engine and component performance with assumed modifications of the burner and bearing characteristics, to prediction of component and engine operation during engine acceleration, and to estimates of the performance of the engine and the components when the exhaust gas was used to drive a power turbine.
[Characteristics of the Chinese human milk banks' operation].
2017-08-02
Objective: To assess the operation status of human milk banks in the mainland of China. Method: This retrospective study included a consecutive series of 14 human milk banks in the mainland of China from March 2013 to December 2016. The opened date, condition of donated breast milk, characteristics of donors and clinical application of donated breast milk were analyzed. Result: There were 14 human milk banks successively founded in mainland China from March 2013 to December 2016. The number of human milk banks, the amount of donated breast milk, the number of eligible donors and the times of donation had increased each year. Howere, the operation status among these milk banks varied greatly. Among them, one human milk bank has newly opened without relevant data, 6 banks could accept frozen breast milk, and the remaining 7 banks could only collect breast milk by the nurses in the bank. Among the 3 121 eligible donors, 1 404 (45.0%) donated less than 3 times, 2 553 (81.8%) aged 25 to 35 years, 2 828 (90.6%) had term delivery, 2 409 (77.2%) began donation one month after birth, 1 798 (57.6%) were company employees and housewives and 1 891 (60.6%) had bachelor or higher degree. The use of donor breast milk, the number of recipients and the average received amount of breast milk every person varied greatly among these banks. Conclusion: The human milk banking developed quickly in the mainland of China. Howere, the number of donors and the amount of donated breast milk which could not meet the clinical demands should be improved. And it was urgent to establish the standards or guidelines of the human milk banking as soon as possible in China.
Breckinridge Project, initial effort. Report IX. Operating cost estimate
Energy Technology Data Exchange (ETDEWEB)
None
1982-01-01
Operating costs are normally broken into three major categories: variable costs including raw materials, annual catalyst and chemicals, and utilities; semi-variable costs including labor and labor related cost; and fixed or capital related charges. The raw materials and utilities costs are proportional to production; however, a small component of utilities cost is independent of production. The catalyst and chemicals costs are also normally proportional to production. Semi-variable costs include direct labor, maintenance labor, labor supervision, contract maintenance, maintenance materials, payroll overheads, operation supplies, and general overhead and administration. Fixed costs include local taxes, insurance and the time value of the capital investment. The latter charge often includes the investor's anticipated return on investment. In determining operating costs for financial analysis, return on investment (ROI) and depreciation are not treated as cash operating costs. These costs are developed in the financial analysis; the annual operating cost determined here omits ROI and depreciation. Project Annual Operating Costs are summarized in Table 1. Detailed supporting information for the cost elements listed below is included in the following sections: Electrical, catalyst and chemicals, and salaries and wages.
WEIGHTED ESTIMATES FOR COMMUTATORS OF POTENTIAL OPERATORS ON SPACES OF HOMOGENEOUS TYPE
Institute of Scientific and Technical Information of China (English)
Wenming Li; Xiaowu Yu; Xuefang Yan
2009-01-01
We derive some strong type and weak type weighted norm estimates which relate the commutators of potential integral operators to the corresponding maximal operators in the context of spaces of homogeneous type.
Engineer’s estimate reliability and statistical characteristics of bids
Directory of Open Access Journals (Sweden)
Fariborz M. Tehrani
2016-12-01
Full Text Available The objective of this report is to provide a methodology for examining bids and evaluating the performance of engineer’s estimates in capturing the true cost of projects. This study reviews the cost development for transportation projects in addition to two sources of uncertainties in a cost estimate, including modeling errors and inherent variability. Sample projects are highway maintenance projects with a similar scope of the work, size, and schedule. Statistical analysis of engineering estimates and bids examines the adaptability of statistical models for sample projects. Further, the variation of engineering cost estimates from inception to implementation has been presented and discussed for selected projects. Moreover, the applicability of extreme values theory is assessed for available data. The results indicate that the performance of engineer’s estimate is best evaluated based on trimmed average of bids, excluding discordant bids.
Blade Bearing Friction Estimation of Operating Wind Turbines
DEFF Research Database (Denmark)
Perisic, Nevena; Pedersen, Bo Juul; Kirkegaard, Poul Henning
2012-01-01
Blade root bearing on a wind turbine (WTG) enables pitching of blades for power control and rotor braking and is a WTG critical component. As the size of modern WTGs is constantly increasing, this leads to relatively less rigid bearings, more sensitive to deformations, thus WTG operational...... reliability can be increased by continuous monitoring of blade bearing. High blade bearing friction is undesirable, as it may be associated with excessive heating of the surfaces, damage and/or inefficient operation. Thus, continuous observation of bearing friction level is crucial for blade bearing health...
NUMATH: a nuclear-material-holdup estimator for unit operations and chemical processes
Energy Technology Data Exchange (ETDEWEB)
Krichinsky, A.M.
1983-02-01
A computer program, NUMATH (Nuclear Material Holdup Estimator), has been developed to estimate compositions of materials in vessels involved in unit operations and chemical processes. This program has been implemented in a remotely operated nuclear fuel processing plant. NUMATH provides estimates of the steady-state composition of materials residing in process vessels until representative samples can be obtained and chemical analyses can be performed. Since these compositions are used for inventory estimations, the results are determined for the cataloged in container-oriented files. The estimated compositions represent materials collected in applicable vessels - including consideration for materials previously acknowledged in these vessels. The program utilizes process measurements and simple performance models to estimate material holdup and distribution within unit operations. In simulated run-testing, NUMATH typically produced estimates within 5% of the measured inventories for uranium and within 8% of the measured inventories for thorium during steady-state process operation.
Influence of hydrophibization of impellers of centrifugal pumps on their operating characteristics
Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Šoukal, J.; Sedlář, M.; Komárek, M.
2016-12-01
This work presents experimental estimation results of changing of basic operation characteristics of a group of centrifugal pumps covering a range of values of dimensionless power-speed coefficient n s from 33 to 330 after hydrophobization of their impellers' surfaces. Hydrophobization of functional surfaces of impellers in all experiments was performed by formation of structures of organic covers by technology of MPEI NRU, which provides increasing of limiting wetting angle of surfaces to 120° and greater. Results of experimental researches of the influence of hydrophobization of impeller surfaces for high-speed pump ( n s = 330) on its characteristics is presented for the first time. Positive effect of applying hydrophobization technology to impeller surfaces in all the considered range of power-speed coefficient was generalized and estimated. It was shown that hydrophobization of impeller surfaces of centrifugal pumps provides increment to their efficiency factors within an acceptable operation range from 0.5 to 7.5%. Empiric function defining dependencies of efficiency factor increment of pump on relative supply and power-speed coefficient are suggested. Possibilities and estimation of extending acceptable operation range of a pump depending on powerspeed coefficient as a result of impeller surface hydrophobization are shown. Experimental data of comparative cavitation tests of high-speed pumps before and after hydrophobization of their impeller surfaces are generalized for the first time for considered range of power-speed coefficient values. The influence of power-speed coefficient on changing of critical net pump suction head (critical positive suction pressure) is shown. Based on existing knowledge on pumps, an attempt to validate experimentally obtained lows of changing of power and anticavitation features of centrifugal pumps after hydrophobization of their impeller surfaces is made.
The Acquisition Cost-Estimating Workforce. Census and Characteristics
2009-01-01
Abbreviations AAC Air Armament Center ACAT acquisition category ACEIT Automated Cost Estimating Integrated Tools AF Air Force AFB Air Force Base AFCAA Air...3 3 4 Automated Cost Estimating Integrated Tools ( ACEIT ) 0 1 12 6 Tecolotea training 0 0 10 5 Other 3 13 24 18 No training 18 4 29 18 Total 100 100...other sources, including AFIT, ACEIT ,9 or the contracting agency that employed them. The remain- ing 29 percent reported having received no training
Zhen, D.; Tesfa, B.; Yuan, X.; Wang, R.; Gu, F.; Ball, A. D.
2012-05-01
In this paper, an experimental investigation has been carried out on the acoustic characteristics of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The experiment was conducted on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine which runs with biodiesel (B50 and B100) and pure diesel. The signals of acoustic, vibration and in-cylinder pressure were measured during the experiment. To correlate the combustion process and the acoustic characteristics, both phenomena have been investigated. The acoustic analysis resulted in the sound level being increased with increasing of engine loads and speeds as well as the sound characteristics being closely correlated to the combustion process. However, acoustic signals are highly sensitive to the ambient conditions and intrusive background noise. Therefore, the spectral subtraction was employed to minimize the effects of background noise in order to enhance the signal to noise ratio. In addition, the acoustic characteristics of CI engine running with different fuels (biodiesel blends and diesel) was analysed for comparison. The results show that the sound energy level of acoustic signals is slightly higher when the engine fuelled by biodiesel and its blends than that of fuelled by normal diesel. Hence, the acoustic characteristics of the CI engine will have useful information for engine condition monitoring and fuel content estimation.
Research about reactor operator's personability characteristics and performance
Energy Technology Data Exchange (ETDEWEB)
Wei Li; He Xuhong; Zhao Bingquan [Tsinghua Univ., Institute of Nuclear Energy Technology, Beijing (China)
2003-03-01
To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)
Ainalis, Daniel; Rouillard, Vincent; Sek, Michael
2016-06-01
This paper describes the application of a practical analytical technique based on the random decrement method to estimate the rigid sprung mass dynamic characteristics (frequency response function) of road vehicles using only vibration response data during constant-speed operation. A brief history and development of the random decrement technique is presented, along with a summary of work undertaken on optimal parameter selection to establish the random decrement signature. Two approaches to estimate the dynamic characteristics from the random decrement signature are described and evaluated. A custom, single-wheeled vehicle (physical quarter car) was commissioned to undertake a series of on-the-road experiments at various nominally constant operating speeds. The vehicle, also instrumented as an inertial profilometer, simultaneously measured the longitudinal pavement profile to establish the vehicle's actual dynamic characteristics during operation. The main outcome of the paper is that the random decrement technique can be used to provide accurate estimates of the sprung mass mode of the vehicle's dynamic characteristics for both linear and nonlinear suspension systems of an idealised vehicle.
Man-hour Estimation Model based on Standard Operation Unit for Flexible Manufacturing System
Directory of Open Access Journals (Sweden)
Ye Zhenggeng
2017-01-01
Full Text Available In flexible manufacturing system, the estimation of man-hour is a difficult problem because of its production-diversity. To explore a more effective method, this paper tried to estimate man-hour from the perspective of operation`s character by establishing standard operation unit (SOU in this paper. A method of parameterizing the SOU is proposed, and a new man-hour estimation model is established on the basis of SOU. At last, this paper verified the effectiveness of this method by the operation of large-scale welding parts.
Annualized TASAR Benefit Estimate for Alaska Airlines Operations
Henderson, Jeffrey
2015-01-01
The Traffic Aware Strategic Aircrew Request (TASAR) concept offers onboard automation for the purpose of advising the pilot of traffic compatible trajectory changes that would be beneficial to the flight. A fast-time simulation study was conducted to assess the benefits of TASAR to Alaska Airlines. The simulation compares historical trajectories without TASAR to trajectories developed with TASAR and evaluated by controllers against their objectives. It was estimated that between 8,000 and 12,000 gallons of fuel and 900 to 1,300 minutes could be saved annually per aircraft. These savings were applied fleet-wide to produce an estimated annual cost savings to Alaska Airlines in excess of $5 million due to fuel, maintenance, and depreciation cost savings. Switching to a more wind-optimal trajectory was found to be the use case that generated the highest benefits out of the three TASAR use cases analyzed. Alaska TASAR requests peaked at four to eight requests per hour in high-altitude Seattle center sectors south of Seattle-Tacoma airport.
(RR) soybean cultivars estimated by phenotypic characteristics and ...
African Journals Online (AJOL)
SAM
2014-06-25
Jun 25, 2014 ... phenotypic characteristics and microsatellite molecular markers (SSR). Ten agronomic traits ... genetic variations at the DNA, which are inherited genetically. ...... having been responsible for the development of RR. Villela et al. ..... soybean cultivars: evolution over time and breeding implications. Genet. Mol.
Perkins, Neil J; Schisterman, Enrique F; Vexler, Albert
2013-07-01
Biomarkers are of ever-increasing importance to clinical practice and epidemiologic research. Multiple biomarkers are often measured per patient. Measurement of true biomarker levels is limited by laboratory precision, specifically measuring relatively low, or high, biomarker levels resulting in undetectable levels below, or above, a limit of detection (LOD). Ignoring these missing observations or replacing them with a constant are methods commonly used although they have been shown to lead to biased estimates of several parameters of interest, including the area under the receiver operating characteristic (ROC) curve and regression coefficients. We developed asymptotically consistent, efficient estimators, via maximum likelihood techniques, for the mean vector and covariance matrix of multivariate normally distributed biomarkers affected by LOD. We also developed an approximation for the Fisher information and covariance matrix for our maximum likelihood estimations (MLEs). We apply these results to an ROC curve setting, generating an MLE for the area under the curve for the best linear combination of multiple biomarkers and accompanying confidence interval. Point and confidence interval estimates are scrutinized by simulation study, with bias and root mean square error and coverage probability, respectively, displaying behavior consistent with MLEs. An example using three polychlorinated biphenyls to classify women with and without endometriosis illustrates how the underlying distribution of multiple biomarkers with LOD can be assessed and display increased discriminatory ability over naïve methods. Properly addressing LODs can lead to optimal biomarker combinations with increased discriminatory ability that may have been ignored because of measurement obstacles. Published by Elsevier Inc.
Eye Tracking Metrics for Workload Estimation in Flight Deck Operation
Ellis, Kyle; Schnell, Thomas
2010-01-01
Flight decks of the future are being enhanced through improved avionics that adapt to both aircraft and operator state. Eye tracking allows for non-invasive analysis of pilot eye movements, from which a set of metrics can be derived to effectively and reliably characterize workload. This research identifies eye tracking metrics that correlate to aircraft automation conditions, and identifies the correlation of pilot workload to the same automation conditions. Saccade length was used as an indirect index of pilot workload: Pilots in the fully automated condition were observed to have on average, larger saccadic movements in contrast to the guidance and manual flight conditions. The data set itself also provides a general model of human eye movement behavior and so ostensibly visual attention distribution in the cockpit for approach to land tasks with various levels of automation, by means of the same metrics used for workload algorithm development.
Estimating the cost of operating cancer registries: Experience in Colombia.
de Vries, Esther; Pardo, Constanza; Arias, Nelson; Bravo, Luis Eduardo; Navarro, Edgar; Uribe, Claudia; Yepez, María Clara; Jurado, Daniel; Garci, Luz Stella; Piñeros, Marion; Edwards, Patrick; Beebe, Maggie Cole; Tangka, Florence; Subramanian, Sujha
2016-12-01
Maintaining population-based registries requires adequate and sustained resources; however, to date there has been no systematic evaluation to identify the resource needs for cancer registration in most countries, including Colombia. A systematic assessment of the costs can quantify the funding required and identify processes to improve efficiency of cancer registries. The Centers for Disease Control and Prevention's (CDC's) International Registry Costing Tool (IntRegCosting Tool) was tailored specifically for the Colombian registries and was used to collect resource use data from five regional population-based cancer registries: Barranquilla, Bucaramanga, Cali, Manizales, and Pasto. The registries provided cost data for the year 2013 and cancer cases corresponding to the year 2010. We identified an almost threefold variation in the average cost per case (77,932 to 214,082 Colombian pesos or US $41 to US $113 in 2013) across the registries, but there were also substantial differences in data collection approaches, types of data collected, and activities performed. Cost per inhabitant varied between 95 and 415 Colombian pesos (US $0.05 to US $0.22). Between 20% and 45% of the total cost was due to fixed cost activities. The detailed economic information presented in this study constitutes a valuable source of activity-based cost data that registries can use to compare operations, assess key factors that lead to differences in cost per case, and identify potential approaches to improve efficiencies. Furthermore, the knowledge gained from studying the Colombian registries can help inform the planning and operations of other registries in the region. Published by Elsevier Ltd.
Bui, The Anh; D'Ancona, Piero; Duong, Xuan Thinh; Li, Ji; Ly, Fu Ken
2017-02-01
Let La be a Schrödinger operator with inverse square potential a | x|-2 on Rd, d ≥ 3. The main aim of this paper is to prove weighted estimates for fractional powers of La. The proof is based on weighted Hardy inequalities and weighted inequalities for square functions associated to La. As an application, we obtain smoothing estimates regarding the propagator e itLa.
A Spreadsheet for Estimating Soil Water Characteristic Curves (SWCC)
2017-05-01
predict the water retention curve from basic geotechnical properties. Canadian Geotechnical Journal 40: 1104–1122. Benson, C., I. Chiang, T... Canadian Geotechnical Journal , 47, 1382-1400. Farrel, D. A., and W. E. Larson. 1972. Modelling the pore structure of porous media. Water Resour. Res., 3...699-706. Fredlund, D. G., and A. Xing. 1994. Equations for the soil-water characteristic curve. Canadian Geotechnical Journal 31:521-532
[Comparative estimation of morphofunction characteristics alive and fixed erythrocytes].
Skorkina, M Iu; Fedorova, M Z; Cherniavskikh, S D; Zabiniakov, N A; Sladkova, E A
2011-01-01
The method of power spectroscopy carries out the quantitative analysis of elastic properties of alive cells. It has been established that the highest indicators of elasticity nuclear (amphibious) and denuclearized (mammals) alive erythrocytes are registered in epi- and perinuclear space. When fixing with methanol and drying of cells the greatest values of the elastic modulus are displaced to the periphery of the cells. The revealed inversion of elasticity properties of erythrocytes must be considered when assessing the morphofunction characteristics of the fixed cells.
Admissible estimation of linear functions of characteristic values of a finite population
Institute of Scientific and Technical Information of China (English)
邹国华; 成平; 冯士雍
1997-01-01
The problem on admissibility of estimators is considered based on the point of view of the superpopu-tation model. The necessary and sufficient conditions for linear estimators of an arbitrary linear function of characteristic values of a finite population to be admissible in the class of linear or all estimators are obtained respectively.
Characteristic estimation of radial blowers; Kennfeldabschaetzung fuer Radialventilatoren
Energy Technology Data Exchange (ETDEWEB)
Draxler, D. [Architekturbuero F. Draxler, Duesseldorf (Germany)
2002-12-01
Radial blowers are an important cost factor in space HVAC systems. For cost reduction purposes, designers are interested in a simple, time-saving method of calculating dimensions and characteristics of radial rotors with minimum hydraulic losses. The solution is based primarily on knowledge of the power loss factor. [German] Radialventilatoren verursachen einen hohen Anteil an den laufenden Betriebskosten vieler lufttechnischer Anlagen. Um diese moeglichst gering zu halten, ist der Konstrukteur an einem einfachen und zeitsparenden Entwurfsverfahren interessiert, welches die Bemessungsgroessen und Kennlinien radialer Laufraeder liefert, die minimale hydraulische Verluste aufweisen. Unter diesen Voraussetzungen basiert die Loesung des Problems im Wesentlichen auf der Kenntnis des Minderleistungsfaktors. (orig.)
14 CFR 27.939 - Turbine engine operating characteristics.
2010-01-01
... drive system associated with critical combinations of power, rotational speed, and control displacement... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27... of airflow distortion during normal operation, cause vibration harmful to the engine. (c) For...
14 CFR 29.939 - Turbine engine operating characteristics.
2010-01-01
... drive system associated with critical combinations of power, rotational speed, and control displacement... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29... of airflow distortion during normal operation, cause vibration harmful to the engine. (c) For...
Operational characteristics optimization of human-computer system
Zulquernain Mallick; Irfan Anjum Badruddin magami; Khaleed Hussain Tandur
2010-01-01
Computer operational parameters are having vital influence on the operators efficiency from readability viewpoint. Four parameters namely font, text/background color, viewing angle and viewing distance are analyzed. The text reading task, in the form of English text, was presented on the computer screen to the participating subjects and their performance, measured in terms of number of words read per minute (NWRPM), was recorded. For the purpose of optimization, the Taguchi method is u...
Thermal-hydraulic characteristics of natural circulation operation for decay heat removal of LMFBR
Energy Technology Data Exchange (ETDEWEB)
Koga, Tomonari [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan); Watanabe, Osamu [Advanced Reactor Technology Co., Ltd., Tokyo (Japan)
2000-10-01
Thermal-hydraulic characteristics of the decay heat removal system (DHRS) has been evaluated by both a water test and its computational analysis. The direct reactor auxiliary cooling system (DRACS) was studied as a representative DHRS in the LMFBR design. A natural circulation flow of the DRACS is originated from the buoyancy force balanced with the pressure loss within the active core. Hence it appears that the performance of the DRACS could be fully estimated by the thermal-hydraulic study of one fuel sub-assembly under the condition of low flow rate. The inter-wrapper flow occurring in the gap between core sub-assemblies under the natural circulation operation might have a large capacity to cool the core. An inverse flow occurring at the outer region of the core was due to the cooling effect of the inter-wrapper flow. (author)
Directory of Open Access Journals (Sweden)
Emre DEMIR
2016-10-01
Full Text Available Objective: Markers which are used for classification into two groups, such as patient / healthy, benign/malignant or prediction of optimal cut off value for diagnostic test and evaluating the performance of diagnostic tests is evaluated by Receiver Operating Characteristic (ROC curve in the diagnostic test researches. In classification accuracy research, some variables such as gender and age, commonly is not similar in groups. In these cases, covariates should be considered to estimate in the area under ROC and covariate adjustment for ROC should be performed. This study aims to introduce methods in the literature for the effect of covariate adjustment and to present an application with sample from the health field. Material and Methods: In the study, we introduced methods used in the literatüre for covariate adjustment and prediction of the area under ROC curves as well as an application with data from the field of urology. In this study, 105 PSA (prostate specific antigen measurements were taken in order to examine the covariate effect for the age variable and to assess the diagnostic performance of PSA measurements with regard to pathologic methods. Results: Covariate effect were found statistically significant with 0.733 parameter estimation of the age in ROC curves analysis with PSA data (p<0.001. According to the methods (Non-parametric (empirical, non-parametric (normal, semi-parametric (empirical, parametric (normal that estimates of the area under ROC curves which is obtained without covariate effect were found 0.708, 0.629, 0.709 and 0.628, respectively, by using PSA measurements. Area under the curve that obtained by covariate adjustment were significantly lower as compared to the traditional ROC with estimation 0.580, 0.577, 0.582 and 0.579. Conclusion: Area under the ROC curves should be estimated with adjustment according to the covariates that could affect the markers value of diagnostic tests performed in concert with matching
Directory of Open Access Journals (Sweden)
Feng Qi
2014-10-01
Full Text Available The authors find the absolute monotonicity and complete monotonicity of some functions involving trigonometric functions and related to estimates the lower bounds of the first eigenvalue of Laplace operator on Riemannian manifolds.
Khan, M.A.; Kerkhoff, Hans G.
2013-01-01
System dependability has become important for critical applications in recent years as technology is moving towards smaller dimensions. Achieving high dependability can be supported by reliability estimations during the operational life. In addition this requires a workflow for regularly monitoring
Khan, Muhammad Aamir; Kerkhoff, Hans G.
2013-01-01
System dependability has become important for critical applications in recent years as technology is moving towards smaller dimensions. Achieving high dependability can be supported by reliability estimations during the operational life. In addition this requires a workflow for regularly monitoring
2007-03-01
Document, 2006. 26. D. Mehrholz, W. Flury R. Jehn H. Klinkrad M. Landgraf, L. Leushacke. “De- tecting, Tracking and Imaging Space Debris ”. Eurpean Space ...SPACECRAFT PROXIMITY OPERATIONS USED TO ESTIMATE THE DYNAMICAL & PHYSICAL PROPERTIES OF A RESIDENT SPACE OBJECT THESIS Abraham Franz Brunner, First...OPERATIONS USED TO ESTIMATE THE DYNAMICAL & PHYSICAL PROPERTIES OF A RESIDENT SPACE OBJECT THESIS Presented to the Faculty Department of Aeronautics and
Institute of Scientific and Technical Information of China (English)
Veli B SHAKHMUROV
2008-01-01
The unique continuation theorems for the anisotropic partial differential-operator equations with variable coefficients in Banach-valued Lp-spaces are studied. To obtain the uniform maximal regularity and the Carleman type estimates for parameter depended differential-operator equations, the sufficient conditions are founded. By using these facts, the unique continuation properties are established. In the application part, the unique continuation properties and Carleman estimates for finite or infinite systems of quasielliptic partial differential equations are studied.
An Estimation of Operator's Diagnostic Time for Feed-And-Bleed Operation under Various Scenarios
Energy Technology Data Exchange (ETDEWEB)
Kim, Bo Gyung; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Yoon, Ho Joon [Khalifa University of Science, Abu Dhabi (United Arab Emirates)
2015-10-15
In order to assess realistic safety of plant, effects of interactions between components, operator, and plant condition are needed to be considered in the PSA model. One of the important issues to estimate the CDF is the estimation of human error probability (HEP). When an accident occurs, operators follow the emergency operating procedure and check various alarm, parameters, and signals. In the conventional Korean PSA model, the Korean standard HRA (K-HRA) method is used. In this method, the HEP is the sum of diagnosis error probability and execution error probability. A diagnosis error probability is expressed by the available time for diagnosis and adjusting performance shaping factors, and an execution error probability is a function of task type and stress level. Available time for diagnosis is very important factor of HEP. If the available time for diagnosis is short, the HEP becomes high. In order to obtain the realistic risk assessment results, we first focus on the estimation of HEP considering the plant dynamics under various scenarios. Target operation and scenarios are feed-and bleed operation (F and B operation) and total loss of feedwater (TLOFW) accident with/without loss of coolant accident (LOCA). One of the highest HEP is HEP of FnB operation. In additional, Scenarios, which are related to combination secondary heat removal failure and primary heat removal failure, are most critical core damage scenario of the combined accident except scenarios related to station black out (SBO). In these scenarios, the FnB operation is last resort to prevent core damage. To estimate available operator diagnosis time, we identify the relationship between accidents, mitigation function, and plant condition. Distribution of available time of diagnosis was estimated using the MOSAIQUE. The variables are break size, break timing, trip timing of RCP, and availability of high pressure safety injection (HPSI) pump under the TLOFW accident with LOCA. For Type 1 accident
Operating characteristics of isocaloric fountain-effect pumps
Kittel, Peter
1988-01-01
The governing equations of thermomechanical (fountain-effect) pumps are usually given for pumps operating at a constant temperature difference. These are the thermomechanical and mechanocaloric effects in which the pressure head and mass flow are independent of each other. Here, these equations are recast for a pump operating at a constant heat input (isocaloric). This form more closely represents how such pumps are likely to be used. Under these conditions, the pressure head and mass flow are shown to be related. For ideal pumps, the head and flow are related by a universal curve. For real pumps (those that have normal fluid leakage), a family of curves is developed. These curves approach the curve for an ideal pump at high flow rates. The isocaloric equations are also extended to multistage pumps.
Refrigerating machine operating characteristics under various mixed refrigerant mass charges
Energy Technology Data Exchange (ETDEWEB)
Rozhentsev, Andrey [Far Eastern State Transport University of the Russian Federation, Seryshev street, 47, 680021 Khabarovsk (Russian Federation)
2008-11-15
This paper reports the results of experimental investigation of a low-temperature Joule-Thomson refrigerating machine, working by use of a non-azeotropic mixture of refrigerants and with a single-stage hermetic compressor. The temperature, hydraulic and power performance of the machine are determined experimentally in relation to the mixed refrigerant (MR) mass charge. Variations of the MR refrigerating machine operating performance with the working mixture mass charge are found to be considerably different from the analogous performance variations of a refrigerating machine charged with a pure refrigerant. The peculiarities of those relationships are analyzed theoretically. The specific value of a minimum acceptable MR mass charge for the investigated system and its correlation with internal processes in the machine loop are established as well. If the refrigerant mixture mass charges are below the minimum ones, the temperature and power performance of the MR machine differ essentially from the design performance and such operating modes are considered inadmissible. (author)
Directory of Open Access Journals (Sweden)
Ali Tavakoli Kashani
2016-01-01
Full Text Available BACKGROUND:In Iran more than 25% of crash fatalities belong to motorcycle operators and passengers in the recent years, from which about 20% are related to passenger fatalities. METHODS: The aim of this study was to investigate the motorcycle operator and passenger characteristics as well as other contributory factors that may affect the fatality risk of motorcyclists involved in traffic crashes. To this end, motorcycle crash data between 2009 and 2012 was extracted from Iran traffic crash database and a logistic regression analysis was performed to obtain odds ratio estimates for each of the study variables. RESULTS: The fatality risk of motorcyclists has a direct relationship with the number of pillion passengers carried. Results also indicate that the amount of increase in the likelihood of having a fatality in a motorcycles crash is considerably higher when the operator is accompanied by a male passenger of the same age. Furthermore, results showed that if the crash is occurred in the darkness, on curves, in rural areas and on highways, then the crash would be more likely to be fatal. Moreover, the head-on collisions, older operators, unlicensed operators and not using a safety helmet were found to increase the likelihood of a fatality in a motorcycle crash. CONCLUSIONS: Preventative measures such as, imposing stricter rules regarding safety helmet usage and confining the number of pillion passengers to one, might be implemented to reduce the fatality risk in motorcycle crashes. In addition, more appropriate infrastructures for penalizing offending motorcyclists could also reduce the frequency of law violations such as not wearing helmet or riding without motorcycle license, which in turn, would result into a reduction in the fatality risk of motorcycle crashes
Institute of Scientific and Technical Information of China (English)
ZHU Min; SONG Ming-xin; GUI Tai-long; WANG Xuan; YIN Jing-hua; WANG Dong-xing; ZHAO Hong
2005-01-01
The creation of Au/CuPc/Al/CuPc/structure is a perpendicular type electricity found in the channel of organic static induction transistor. In the following we analyze transistor operation characteristics and machine structural relation. The results express that the transistor drives the voltage low and has no-saturation currentvoltage characteristics. Its operation characteristics are dependant on gate bias voltage and the construction of the aluminum electrode.The vertical channel of organic static induction transistor (OSIT) , with structure of Au/CuPc/Al/CuPc/Cu, has been determined. According to the test results, the relation of its operation characteristics and device structure was analyzed. The results show that this transistor has a low driving voltage and unsaturation Ⅰ-Ⅴ characteristics. Its operation characteristics are dependant on gate bias voltage and the structure of the aluminum electrode.
Estimate of Heritability for Maturity Characteristics of an Early x Late ...
African Journals Online (AJOL)
Narrow sense heritabilities of maturity characteristics of common beans were estimated using the ... additive gene effects play an important. role in the inheritance of DFF, hence early generation .... mean of the original F z population (Xo)'.
Strichartz Estimates for the Schrödinger Propagator for the Laguerre Operator
Indian Academy of Sciences (India)
Vijay Kumar Sohani
2013-11-01
We obtain homogeneous Strichartz estimate for the Schrödinger propagator $e^{-itL_}$ for the Laguerre operator $L_$ on $\\mathbb{R}^n_+$. We follow regularization technique as introduced in J. Funct. Anal. 224(2) (2005) 371–385. We also establish inhomogeneous Strichartz estimates for different admissible pairs.
INDIVIDUAL PSYCHOLOGICAL CHARACTERISTICS OF RAILWAYS OPERATORS OF DIFFERENT AGE GROUPS
Directory of Open Access Journals (Sweden)
Bugaeva V. M.
2015-10-01
Full Text Available The article presents the results of the study of some individual psychological characteristics of the drivers of rail transport in the age groups 25–34 and 35–45 years. We have identified a number of differences between the two age groups associated with both features individually-psychological sphere, and in the psycho-physiological features. Features of age-related psychological differences can be explained by the age characteristics of the representatives of each group; psycho-physiological features of age differences may reflect developed in the course of a long professional activity features. We have also developed adaptive strategies, consciously or unconsciously selected during the long-running monotonous activities and in small social groups (teams of drivers allow, on the one hand, higher quality performance of their professional duties, on the other — to avoid the harmful effects of stressful situations at work. It can be assumed that the composition of drivers age group 35– 45 years is the result of natural selection, when those who did not cope with this type of activity is simply dismissed or transferred to other kinds of professions
Energy Technology Data Exchange (ETDEWEB)
Myers, M.L.; Fuller, L.C.
1979-01-01
Revised guidelines are presented for estimating annual nonfuel operation and maintenance costs for large steam-electric power plants, specifically light-water-reactor plants and coal-fired plants. Previous guidelines were published in October 1975 in ERDA 76-37, a Procedure for Estimating Nonfuel Operating and Maintenance Costs for Large Steam-Electric Power Plants. Estimates for coal-fired plants include the option of limestone slurry scrubbing for flue gas desulfurization. A computer program, OMCOST, is also presented which covers all plant options.
Operational characteristics optimization of human-computer system
Directory of Open Access Journals (Sweden)
Zulquernain Mallick
2010-09-01
Full Text Available Computer operational parameters are having vital influence on the operators efficiency from readability viewpoint. Four parameters namely font, text/background color, viewing angle and viewing distance are analyzed. The text reading task, in the form of English text, was presented on the computer screen to the participating subjects and their performance, measured in terms of number of words read per minute (NWRPM, was recorded. For the purpose of optimization, the Taguchi method is used to find the optimal parameters to maximize operators’ efficiency for performing readability task. Two levels of each parameter have been considered in this study. An orthogonal array, the signal-to-noise (S/N ratio and the analysis of variance (ANOVA were employed to investigate the operators’ performance/efficiency. Results showed that Times Roman font, black text on white background, 40 degree viewing angle and 60 cm viewing distance, the subjects were quite comfortable, efficient and read maximum number of words per minute. Text/background color was dominant parameter with a percentage contribution of 76.18% towards the laid down objective followed by font type at 18.17%, viewing distance 7.04% and viewing angle 0.58%. Experimental results are provided to confirm the effectiveness of this approach.
ESTIMATION OF THE MAIN CHARACTERISTICS OF THE TRACTION BLDC MOTOR ON THE BASIS OF VEHICLE ALTERNATOR
Directory of Open Access Journals (Sweden)
V. Dvadnenko
2014-10-01
Full Text Available A method of estimation of basic parameters of the BLDC motor based on the vehicle powerful alternator to convert an ordinary vehicle into a hybrid one is offered. The results of estimation of basic characteristics of the electric motor on the basis of the automobile alternator G290 are presented.
Subjective mood estimation co-varies with spectral power EEG characteristics
Wyczesany, M.; Kaiser, J.; Coenen, A.M.L.
2008-01-01
Co-variation between subjectively estimated mood/activation and EEG characteristics, based on spectral power parameters, was investigated. Subjective estimation of mood was made by using Thayer’s Activation-Deactivation Adjective Checklist, which yielded two dimensions: Energy-Tiredness (with Energy
Energy Technology Data Exchange (ETDEWEB)
Rosales Espizua, F. J.; Maneru Camara, F.; Iriondo Igerabide, U.; Forner Forner, A.
2011-07-01
The study of the shielding necessary in operating rooms which are used in X-ray arcs requires a knowledge of workload that is usually difficult to estimate. The national and international recommendations in this regard reflect conditions of use radiological rooms, which is far from the real-time fluoroscopy in the operating room. A realistic estimate of the workload ja crucial, especially considering that the walls of These units are built with leas and leas aLtenuaLing materials. The work consists of a collection of workload in operating rooms that are carried out interventions.
Teacher Characteristics and Gains in Student Achievement: Estimation Using Micro Data
Hanushek, Eric
1971-01-01
Study attempts to provide conclusive answers to questions concerning the worth of teachers, the efficiency of school operations, and teacher/classroom characteristics particularly within a racial-ethnic context. (EA)
Glick, Stephen J; Didier, Clay
2013-10-14
in the spectral response with decreasing detector element size. If not corrected for, this caused a large bias in estimating tissue density parameters for material decomposition. It was also observed that degradation of the spectral response due to characteristic x-rays caused worsening precision in the estimation of tissue density parameters. It was observed that characteristic x-rays do cause some degradation in the spatial and spectral resolution of thin CZT detectors operating under breast CT conditions. These degradations should be manageable with careful selection of the detector element size. Even with the observed spectral distortion from characteristic x-rays, it is still possible to correctly estimate tissue parameters for material decomposition using spectral CT if accurate modeling is used.
WIND TURBINE OPERATION PARAMETER CHARACTERISTICS AT A GIVEN WIND SPEED
Directory of Open Access Journals (Sweden)
Zdzisław Kamiński
2014-06-01
Full Text Available This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.
Estimating the Euler Characteristic of a planar set from a digital image
DEFF Research Database (Denmark)
Kiderlen, Markus
2006-01-01
A new estimator (approximation) for the Euler–Poincare characteristic of a planar set K in the extended convex ring is suggested. As input, it uses only the digital image of K, which is modeled as the set of all points of a regular lattice falling in K. The key idea is to estimate the two planar...... Betti numbers of K (number of connected components and number of holes) by approximating K and its complement by polygonal sets derived from the digitization. In contrast to earlier methods, only certain connected components of these approximations are counted. The estimator of the Euler characteristic...
Operating characteristics of a new ion source for KSTAR neutral beam injection system.
Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul
2014-02-01
A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.
Multi-stage axial flow compressors characteristics estimation based on system identification
Energy Technology Data Exchange (ETDEWEB)
Ma, Wentong; Liu, Yongwen; Su, Ming [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Yu, Nanhua [Guangdong Electric Power Research Institute, 73 Meihua Road, Guangzhou 510600 (China)
2008-02-15
The most troublesome part in the development of a component-based engine models is the compressor module because of the strong dependence of its performance on rotational speed. For this purpose, a performance characteristics estimation method of multi-stage axial flow compressors are proposed in this paper. The newly proposed estimation technique of average infinitesimal stage characteristics satisfies the analogy criterion perfectly due to the use of a new conception of infinitesimal stage and the improved analogy theory. The overall compressor performance characteristics are estimated through a stage by stage calculation based on the improved analogy theory and the average stage characteristics. To minimize the error between the calculated characteristic and the tested characteristic of the compressor at high rotational speeds, the average stages performance characteristics are identified using an optimization method. The technique improves the traditional scaling method by taking into account the effects of air density change and rotational speeds, and it makes use of available data efficiently. In addition, it reflects the own performance characteristics of the original compressor. (author)
Multi-stage axial flow compressors characteristics estimation based on system identification
Energy Technology Data Exchange (ETDEWEB)
Ma Wentong [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: wentongma@sjtu.org; Liu Yongwen; Su Ming [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240 (China); Yu Nanhua [Guangdong Electric Power Research Institute, 73 Meihua Road, Guangzhou 510600 (China)
2008-02-15
The most troublesome part in the development of a component-based engine models is the compressor module because of the strong dependence of its performance on rotational speed. For this purpose, a performance characteristics estimation method of multi-stage axial flow compressors are proposed in this paper. The newly proposed estimation technique of average infinitesimal stage characteristics satisfies the analogy criterion perfectly due to the use of a new conception of infinitesimal stage and the improved analogy theory. The overall compressor performance characteristics are estimated through a stage by stage calculation based on the improved analogy theory and the average stage characteristics. To minimize the error between the calculated characteristic and the tested characteristic of the compressor at high rotational speeds, the average stages performance characteristics are identified using an optimization method. The technique improves the traditional scaling method by taking into account the effects of air density change and rotational speeds, and it makes use of available data efficiently. In addition, it reflects the own performance characteristics of the original compressor.
Modelling complete particle-size distributions from operator estimates of particle-size
Roberson, Sam; Weltje, Gert Jan
2014-05-01
Estimates of particle-size made by operators in the field and laboratory represent a vast and relatively untapped data archive. The wide spatial distribution of particle-size estimates makes them ideal for constructing geological models and soil maps. This study uses a large data set from the Netherlands (n = 4837) containing both operator estimates of particle size and complete particle-size distributions measured by laser granulometry. This study introduces a logit-based constrained-cubic-spline (CCS) algorithm to interpolate complete particle-size distributions from operator estimates. The CCS model is compared to four other models: (i) a linear interpolation; (ii) a log-hyperbolic interpolation; (iii) an empirical logistic function; and (iv) an empirical arctan function. Operator estimates were found to be both inaccurate and imprecise; only 14% of samples were successfully classified using the Dutch classification scheme for fine sediment. Operator estimates of sediment particle-size encompass the same range of values as particle-size distributions measured by laser analysis. However, the distributions measured by laser analysis show that most of the sand percentage values lie between zero and one, so the majority of the variability in the data is lost because operator estimates are made to the nearest 1% at best, and more frequently to the nearest 5%. A method for constructing complete particle-size distributions from operator estimates of sediment texture using a logit constrained cubit spline (CCS) interpolation algorithm is presented. This model and four other previously published methods are compared to establish the best approach to modelling particle-size distributions. The logit-CCS model is the most accurate method, although both logit-linear and log-linear interpolation models provide reasonable alternatives. Models based on empirical distribution functions are less accurate than interpolation algorithms for modelling particle-size distributions in
Estimate of the changes in the characteristics of a PZT vibrator under a space environment
Kim, Jungsoon; Lee, Sanghoon; Kim, Moojoon
2015-03-01
To utilize lead zirconate titanate (PZT) vibrators in the aerospace industry, we formulate the changes in the characteristics of the vibrator for the transverse mode and the thickness mode as functions of the temperature. For practical use, we adopted a few linear functions and a square function as regression functions in order to estimate the characteristics of the commercialized PZT-5 series of ceramics. The input admittance characteristics were calculated using the characteristic functions suggested in this study, and the results showed good agreement with the measured ones.
STATIC CONVERTERS OF THE ELECTRIC POWER WITH IMPROVED OPERATION-TECHNICAL CHARACTERISTICS
Directory of Open Access Journals (Sweden)
Uskov A. E.
2014-03-01
Full Text Available The article describes scopes and new technical decisions of static converters of the electric power with the improved operation-characteristics, executed with use of new element base and a modular principle of construction
A brief history of free-response receiver operating characteristic paradigm data analysis.
Chakraborty, Dev P
2013-07-01
In the receiver operating characteristic paradigm the observer assigns a single rating to each image and the location of the perceived abnormality, if any, is ignored. In the free-response receiver operating characteristic paradigm the observer is free to mark and rate as many suspicious regions as are considered clinically reportable. Credit for a correct localization is given only if a mark is sufficiently close to an actual lesion; otherwise, the observer's mark is scored as a location-level false positive. Until fairly recently there existed no accepted method for analyzing the resulting relatively unstructured data containing random numbers of mark-rating pairs per image. This report reviews the history of work in this field, which has now spanned more than five decades. It introduces terminology used to describe the paradigm, proposed measures of performance (figures of merit), ways of visualizing the data (operating characteristics), and software for analyzing free-response receiver operating characteristic studies.
Energy Technology Data Exchange (ETDEWEB)
Belzer, D.B. (Pacific Northwest Lab., Richland, WA (USA)); Serot, D.E. (D/E/S Research, Richland, WA (USA)); Kellogg, M.A. (ERCE, Inc., Portland, OR (USA))
1991-03-01
Development of integrated mobilization preparedness policies requires planning estimates of available productive capacity during national emergency conditions. Such estimates must be developed in a manner to allow evaluation of current trends in capacity and the consideration of uncertainties in various data inputs and in engineering assumptions. This study developed estimates of emergency operating capacity (EOC) for 446 manufacturing industries at the 4-digit Standard Industrial Classification (SIC) level of aggregation and for 24 key nonmanufacturing sectors. This volume lays out the general concepts and methods used to develop the emergency operating estimates. The historical analysis of capacity extends from 1974 through 1986. Some nonmanufacturing industries are included. In addition to mining and utilities, key industries in transportation, communication, and services were analyzed. Physical capacity and efficiency of production were measured. 3 refs., 2 figs., 12 tabs. (JF)
Operator functional state estimation based on EEG-data-driven fuzzy model.
Zhang, Jianhua; Yin, Zhong; Yang, Shaozeng; Wang, Rubin
2016-10-01
This paper proposed a max-min-entropy-based fuzzy partition method for fuzzy model based estimation of human operator functional state (OFS). The optimal number of fuzzy partitions for each I/O variable of fuzzy model is determined by using the entropy criterion. The fuzzy models were constructed by using Wang-Mendel method. The OFS estimation results showed the practical usefulness of the proposed fuzzy modeling approach.
Trujillo, B. M.
1986-01-01
This paper presents the technique and results of maximum likelihood estimation used to determine lift and drag characteristics of the Space Shuttle Orbiter. Maximum likelihood estimation uses measurable parameters to estimate nonmeasurable parameters. The nonmeasurable parameters for this case are elements of a nonlinear, dynamic model of the orbiter. The estimated parameters are used to evaluate a cost function that computes the differences between the measured and estimated longitudinal parameters. The case presented is a dynamic analysis. This places less restriction on pitching motion and can provide additional information about the orbiter such as lift and drag characteristics at conditions other than trim, instrument biases, and pitching moment characteristics. In addition, an output of the analysis is an estimate of the values for the individual components of lift and drag that contribute to the total lift and drag. The results show that maximum likelihood estimation is a useful tool for analysis of Space Shuttle Orbiter performance and is also applicable to parameter analysis of other types of aircraft.
Heat kernel estimates and spectral properties of a pseudorelativistic operator with magnetic field
Jakubassa-Amundsen, D. H.
2008-03-01
Based on the Mehler heat kernel of the Schrödinger operator for a free electron in a constant magnetic field, an estimate for the kernel of EA=∣α(p-eA)+βm∣ is derived, where EA represents the kinetic energy of a Dirac electron within the pseudorelativistic no-pair Brown-Ravenhall model. This estimate is used to provide the bottom of the essential spectrum for the two-particle Brown-Ravenhall operator, describing the motion of the electrons in a central Coulomb field and a constant magnetic field, if the central charge is restricted to Z ⩽86.
APPLICATIONS OF THE BERNSTEIN-DURRMEYER OPERATORS IN ESTIMATING THE NORM OF MERCER KERNEL MATRICES
Institute of Scientific and Technical Information of China (English)
Chunping Zhang; Baohuai Sheng; Zhixiang Chen
2008-01-01
The paper is related to the norm estimate of Mercer kernel matrices.The lower and upper bound estimates of Rayleigh entropy numbers for some Mercer kernel matrices on[0,1]×[0,1]based on the Bernstein-Durrmeyer operator kernel ale obtained,with which and the approximation property of the Bernstein-Durrmeyer operator the lower and upper bounds of the Rayleigh entropy number and the l2-norm for general Mercer kernel matrices on[0,1]×[0,1]are provided.
Institute of Scientific and Technical Information of China (English)
Veli; B; SHAKHMUROV
2008-01-01
The unique continuation theorems for the anisotropic partial differential-operator equations with variable coeffcients in Banach-valued Lp-spaces are studied.To obtain the uniform maximal regularity and the Carleman type estimates for parameter depended differential-operator equations,the suffcient conditions are founded.By using these facts,the unique continuation properties are established.In the application part,the unique continuation properties and Carleman estimates for finite or infinite systems of quasielliptic partial differential equations are studied.
Visualization of the significance of Receiver Operating Characteristics based on confidence ellipses
Sarlis, Nicholas V.; Christopoulos, Stavros-Richard G.
2014-03-01
The Receiver Operating Characteristics (ROC) is used for the evaluation of prediction methods in various disciplines like meteorology, geophysics, complex system physics, medicine etc. The estimation of the significance of a binary prediction method, however, remains a cumbersome task and is usually done by repeating the calculations by Monte Carlo. The FORTRAN code provided here simplifies this problem by evaluating the significance of binary predictions for a family of ellipses which are based on confidence ellipses and cover the whole ROC space. Catalogue identifier: AERY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERY_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 11511 No. of bytes in distributed program, including test data, etc.: 72906 Distribution format: tar.gz Programming language: FORTRAN. Computer: Any computer supporting a GNU FORTRAN compiler. Operating system: Linux, MacOS, Windows. RAM: 1Mbyte Classification: 4.13, 9, 14. Nature of problem: The Receiver Operating Characteristics (ROC) is used for the evaluation of prediction methods in various disciplines like meteorology, geophysics, complex system physics, medicine etc. The estimation of the significance of a binary prediction method, however, remains a cumbersome task and is usually done by repeating the calculations by Monte Carlo. The FORTRAN code provided here simplifies this problem by evaluating the significance of binary predictions for a family of ellipses which are based on confidence ellipses and cover the whole ROC space. Solution method: Using the statistics of random binary predictions for a given value of the predictor threshold ɛt, one can construct the corresponding confidence ellipses. The envelope of these corresponding confidence ellipses is estimated when
Melnikov, Yuri B.
2016-09-01
Quadratic form approach allows for new results in the analysis of a class of integral-difference operators in finite domains: non-negativity, spectral estimations, a new property of Legendre polynomials, and establishing links with weighted mean-square deviation functionals and with infinite Jacobi matrices with not-bounded coefficients. Generalisation of integral-difference operators to higher dimensions is provided and application to matter relaxation in a field is considered. A new class of special functions naturally appears.
Vasiliades, Lampros; Spiliotopoulos, Marios; Tzabiras, John; Loukas, Athanasios; Mylopoulos, Nikitas
2015-06-01
An integrated modeling system, developed in the framework of "Hydromentor" research project, is applied to evaluate crop water requirements for operational water resources management at Lake Karla watershed, Greece. The framework includes coupled components for operation of hydrotechnical projects (reservoir operation and irrigation works) and estimation of agricultural water demands at several spatial scales using remote sensing. The study area was sub-divided into irrigation zones based on land use maps derived from Landsat 5 TM images for the year 2007. Satellite-based energy balance for mapping evapotranspiration with internalized calibration (METRIC) was used to derive actual evapotranspiration (ET) and crop coefficient (ETrF) values from Landsat TM imagery. Agricultural water needs were estimated using the FAO method for each zone and each control node of the system for a number of water resources management strategies. Two operational strategies of hydro-technical project development (present situation without operation of the reservoir and future situation with the operation of the reservoir) are coupled with three water demand strategies. In total, eight (8) water management strategies are evaluated and compared. The results show that, under the existing operational water resources management strategies, the crop water requirements are quite large. However, the operation of the proposed hydro-technical projects in Lake Karla watershed coupled with water demand management measures, like improvement of existing water distribution systems, change of irrigation methods, and changes of crop cultivation could alleviate the problem and lead to sustainable and ecological use of water resources in the study area.
DEFF Research Database (Denmark)
Bajric, Anela; Brincker, Rune; Thöns, Sebastian
2015-01-01
The Operational Modal Analysis (OMA) techniques provide in most cases reasonably accurate estimates of structural frequencies and mode shapes. They are however known to produce erroneous structural damping estimates, which are presumably thought to be due to inherent random- or bias errors......). The evaluation is based on identification using random response from white noise loading of a three degree-of-freedom (3DOF) system numerically established from specified modal parameters for a range of natural frequencies. The numerical model provides comparisons of the effectiveness of damping estimation...
Estimates of emergency operating capacity in US manufacturing and nonmanufacturing industries
Energy Technology Data Exchange (ETDEWEB)
Belzer, D.B. (Pacific Northwest Lab., Richland, WA (USA)); Serot, D.E. (D/E/S Research, Richland, WA (USA)); Kellogg, M.A. (ERCE, Inc., Portland, OR (USA))
1991-03-01
Development of integrated mobilization preparedness policies requires planning estimates of available productive capacity during national emergency conditions. Such estimates must be developed in a manner that allows evaluation of current trends in capacity and the consideration of uncertainties in various data inputs and in engineering assumptions. This study, conducted by Pacific Northwest Laboratory (PNL), developed estimates of emergency operating capacity (EOC) for 446 manufacturing industries at the 4-digit Standard Industrial Classification (SIC) level of aggregation and for 24 key non-manufacturing sectors. This volume presents tabular and graphical results of the historical analysis and projections for each SIC industry. (JF)
van der Vaart, T; van Donk, DP
2006-01-01
Purpose - Buyer-focused operations aim at a high level of supply chain alignment by singling out resources for one buyer in order to serve this buyer optimally. The purpose of this paper is to identify what business characteristics make suppliers choose buyer-focused operations as a supply chain
Operating characteristics of a three-stage Stirling pulse tube cryocooler operating around 5 K
Qiu, L. M.; Cao, Q.; Zhi, X. Q.; Han, L.; Gan, Z. H.; Yu, Y. B.; Liu, Y.; Zhang, X. J.; Pfotenhauer, J. M.
2012-07-01
A Stirling pulse tube cryocooler (SPTC) operating at the liquid-helium temperatures represents an excellent prospect for satisfying the requirements of space applications because of its compactness, high efficiency and reliability. However, the working mechanism of a 4 K SPTC is more complicated than that of the Gifford McMahon (GM) PTC that operates at the relatively low frequency of 1-2 Hz, and has not yet been well understood. In this study, the primary operating parameters, including frequency, charge pressure, input power and precooling temperature, are systematically investigated in a home-developed separate three-stage SPTC. The investigation demonstrates that the frequency and precooling temperature are closely coupled via phase shift. In order to improve the cooling capacity it is important to lower the frequency and the precooling temperature simultaneously. In contrast to the behavior predicted by previous studies, the pressure dependence of the gas properties results in an optimized pressure that decreases significantly as the temperature is lowered. The third stage reaches a lowest temperature of 4.97 K at 29.9 Hz and 0.91 MPa. A cooling power of 25 mW is measured at 6.0 K. The precooling temperature is 23.7 K and the input power is 100 W.
Institute of Scientific and Technical Information of China (English)
Liu Yinshui; Nie Songlin; Zhu Yuquan; He Xiaofeng; Li Zhuangyun
2004-01-01
Experimental investigations are made on the effects of operating conditions on the flow characteristics of throttle when tap water is used as the working media. The researched throttles include cone poppet valve, ball valve, disc valve and dumping orifice. Operating condition includes poppet lift, working media, back pressure, medium temperature, etc. Because the vapourous pressure of water is much higher than that of oil, cavitation is easier to occur in water hydraulic elements and systems, so the effects of operating conditions on the cavitation characteristics of throttle are also researched.
Cost estimates of operating onsite spent fuel pools after final reactor shutdown
Energy Technology Data Exchange (ETDEWEB)
Rod, S R
1991-08-01
This report presents estimates of the annual costs of operating spent fuel pools at nuclear power stations after the final shutdown of one or more onsite reactors. Its purpose is to provide basic spent fuel storage cost information for use in evaluating DOE's reference nuclear waste management system, as well as alternate systems. The basic model of an independent spent fuel storage installation (ISFSI) used in this study was based on General Electric Corporation's Morris Operation and was modified to reflect mean storage capabilities at an unspecified, or generic,'' US reactor site. Cost data for the model came from several sources, including both operating and shutdown nuclear power stations and existing ISFSIs. Duke Power Company has estimated ISFSI costs based on existing spent fuel storage costs at its nuclear power stations. Similarly, nuclear material handling facilities such as the Morris Operation, the West Valley Demonstration Project, and the retired Humbolt Bay nuclear power station have compiled spent fuel storage cost data based on years of operating experience. Consideration was given to the following factors that would cause operating costs to vary among pools: (1) The number of spent fuel pools at a given reactor site; (2) the number of operating and shutdown reactors onsite; (3) geographic location; and (4) pool storage capacity. 10 ref., 6 figs., 7 tabs.
Energy Technology Data Exchange (ETDEWEB)
Silver, Gary L [Los Alamos National Laboratory
2009-01-01
Equations for interpolating five data in rectangular array are seldom encountered in textbooks. This paper describes a new method that renders polynomial and exponential equations for the design. Operational center point estimators are often more more resistant to the effects of an outlying datum than the mean.
Khan, M.A.; Kerkhoff, Hans G.
2013-01-01
Reliability of electronic systems has been thoroughly investigated in literature and a number of analytical approaches at the design stage are already available via examination of the circuit-level reliability effects based on device-level models. Reliability estimation during operational life of an
Khan, Muhammad Aamir; Kerkhoff, Hans G.
2013-01-01
Reliability of electronic systems has been thoroughly investigated in literature and a number of analytical approaches at the design stage are already available via examination of the circuit-level reliability effects based on device-level models. Reliability estimation during operational life of an
Experimental modeling of Wiener filters estimated on an operating diesel engine
Drouet, Julie; Leclère, Quentin; Parizet, Etienne
2015-01-01
Sound source separation in diesel engines can be implemented using a Wiener filter, or spectrofilter, that can extract the combustion contribution in the overall noise. In this study this filter characterizes the transfer function between a cylinder pressure and a measurement point. An engine is characterized by several filters (one for each cylinder) which are estimated for many operating conditions (engine speed and load). The purpose of this work is to obtain an averaged spectrofilter allowing the synthesis of combustion noise in all operating conditions. This synthesis should be accurate enough to be used in perceptive studies. In order to refine the spectrofilter estimation in the medium frequency band, this paper consists in taking advantage of the multitude of information given by the estimations from different operating conditions. To do this, an experimental model is adopted so modal parameters are extracted from a great number of measured filters. Different procedures such as the ESPRIT method or the LSCE method (modal analysis) are used to decompose the impulse responses on a complex exponential basis. The spectrofilters estimated from different operating conditions are analyzed and compared in this reduced basis, in order to identify the underlying structural parameters. These parameters are compared to the results of an experimental characterization of the stopped engine. The accuracy of the synthesis (number of components of the filter) is an important issue because these filters will be used in perceptive applications, extracting combustion noises. This paper is an extended version of the work initially presented at the conference Surveillance 6 in November 2011 in Compiègne, France [1] (J. Drouet, Quentin Leclere, Etienne Parizet. Experimental modeling of Wiener filters estimated on an operating diesel engine, in: Proceedings of the Surveillance, vol. 6, Compi'egne, France, 2011.).
Rispens, S.M.; Pijnappels, M.A.G.M.; Dieen, van J.H.; Schooten, van K.S.; Beek, P.J.; Daffertshofer, A.
2014-01-01
Characteristics of dynamical systems are often estimated to describe physiological processes. For instance, Lyapunov exponents have been determined to assess the stability of the cardio-vascular system, respiration, and, more recently, human gait and posture. However, the systematic evaluation of
Zhu, Senlai; Guo, Yuntao; Chen, Jingxu; Li, Dawei; Cheng, Lin
2017-08-02
Most existing network sensor location problem (NSLP) models are designed to identify the number of sensors with fixed costs and installation locations, and sensors are assumed to be installed permanently. However, sometimes sensors are carried by individuals to collect traffic data measurements manually at fixed locations. Hence, their duration of operation for which traffic data measurements are collected is limited, and their costs are not fixed as they are correlated with the duration of operation. This paper proposes a NSLP model that integrates optimal heterogeneous sensor deployment and operation strategies for the dynamic O-D demand estimates under budget constraints. The deployment strategy consists of the numbers of link and node sensors and their installation locations. The operation strategy includes sensors' start time and duration of operation, which has not been addressed in previous studies. An algorithm is developed to solve the proposed model. Numerical experiments performed on a network from a part of Chennai, India show that the proposed model can identify the optimal heterogeneous sensor deployment and operation strategies with the maximum dynamic O-D demand estimation accuracy.
Directory of Open Access Journals (Sweden)
van den Dungen C
2011-11-01
Full Text Available Abstract Background General practice based registration networks (GPRNs provide information on morbidity rates in the population. Morbidity rate estimates from different GPRNs, however, reveal considerable, unexplained differences. We studied the range and variation in morbidity estimates, as well as the extent to which the differences in morbidity rates between general practices and networks change if socio-demographic characteristics of the listed patient populations are taken into account. Methods The variation in incidence and prevalence rates of thirteen diseases among six Dutch GPRNs and the influence of age, gender, socio economic status (SES, urbanization level, and ethnicity are analyzed using multilevel logistic regression analysis. Results are expressed in median odds ratios (MOR. Results We observed large differences in morbidity rate estimates both on the level of general practices as on the level of networks. The differences in SES, urbanization level and ethnicity distribution among the networks' practice populations are substantial. The variation in morbidity rate estimates among networks did not decrease after adjusting for these socio-demographic characteristics. Conclusion Socio-demographic characteristics of populations do not explain the differences in morbidity estimations among GPRNs.
Rana, Gianfranco; Katerji, Nader; Ferrara, Rossana M.; Martinelli, Nicola
2011-03-01
In this paper, we present an operational model to estimate the actual evapotranspiration (ET) of crops cultivated on hilly terrains. This new model has the following three characteristics: (1) ET modelling is based on a Penman-Monteith (PM) type equation (Monteith 1965) where canopy resistance is simulated by following an approach already illustrated by Katerji and Perrier (Agronomie 3(6):513-521, 1983); (2) the estimation of ET, by means of the PM equation, is made by using meteorological variables simulated on sloped sites as input; (3) these variables are simulated by using simple relationships linking the variables measured at a reference site on plane to the topographic characteristics of the site (slope, orientation, altitude as difference between reference, and sloped sites). This approach presents two advantages if compared with previously proposed models: Not only computation steps are greatly simplified but also error sources due to the simulation of climatic variables in sloped sites and the ET estimation are well distinguished. This model was validated at hourly and daily scales at four sites cultivated with wheat and oats offering a wide range of slope and orientation values: a reference site on plane, site 1 (9° sloping, NW orientation, 7 m from the reference site in plane), site 2 (6°, SE, 12 m) and site 3 (1°, SE, 18 m). At hourly scale, the new model performed well at all sites studied. The observed slope of the linear relationships between estimated and measured ET values ranged between 0.93 and 1.03, with coefficients of determination, r 2, between 0.80 and 0.98. At daily scale, the slopes of the linear relationships between measured and estimated ET for the sites on plane and the sloped sites were practically the same (0.98 ± 0.01); however, the coefficient of determination r 2 observed in the site on plane was clearly greater (0.98) than that observed in the sloped sites (0.83). The presented analysis does not show any significant
Estimating truck operating costs for domestic trips – case studies from Greece
Directory of Open Access Journals (Sweden)
Sdoukopoulos Eleftherios
2015-11-01
Full Text Available The transport sector represents a vital component of national economies and has significant impacts on productivity and social welfare. In 2012, the transport sector in Europe was estimated to account for 3.7% of the European Gross Domestic Product (GDP and 5.1% for employment. Road transport proves to be the predominant mode for moving goods within Europe holding a share of approximately 45.8% in 2012 (in ton-kms. In Greece, the share of road freight transport is significantly higher (98% indicating the importance of this sector for the Greek economy. To this end and considering the existing needs of road freight transport operators in Greece, the objective of this research is to establish an analytical and documented basis for estimating the operating cost of a truck on specific urban or national freight transport routes. To achieve this goal, an extended literature review has been conducted resulting in the identification of the main components comprising the total truck operating cost, which were then updated and validated through a series of personal interviews with selected road freight transport professionals. An excel-based application tool was also developed in order to facilitate operating cost estimates for different cases, through selection of the proper values of the relevant parameters. The resulting tool was used to analyse four test cases, which demonstrate the tool’s usability and applicability. Results from this analysis have been also validated by industry experts and they reflect real-world transport scenarios.
Luo, Xiaodong
2014-10-01
The ensemble Kalman filter (EnKF) is an efficient algorithm for many data assimilation problems. In certain circumstances, however, divergence of the EnKF might be spotted. In previous studies, the authors proposed an observation-space-based strategy, called residual nudging, to improve the stability of the EnKF when dealing with linear observation operators. The main idea behind residual nudging is to monitor and, if necessary, adjust the distances (misfits) between the real observations and the simulated ones of the state estimates, in the hope that by doing so one may be able to obtain better estimation accuracy. In the present study, residual nudging is extended and modified in order to handle nonlinear observation operators. Such extension and modification result in an iterative filtering framework that, under suitable conditions, is able to achieve the objective of residual nudging for data assimilation problems with nonlinear observation operators. The 40-dimensional Lorenz-96 model is used to illustrate the performance of the iterative filter. Numerical results show that, while a normal EnKF may diverge with nonlinear observation operators, the proposed iterative filter remains stable and leads to reasonable estimation accuracy under various experimental settings.
An innovative multivariate tool for fuel consumption and costs estimation of agricultural operations
Directory of Open Access Journals (Sweden)
Mirko Guerrieri
2016-12-01
Full Text Available The estimation of operating costs of agricultural and forestry machineries is a key factor in both planning agricultural policies and farm management. Few works have tried to estimate operating costs and the produced models are normally based on deterministic approaches. Conversely, in the statistical model randomness is present and variable states are not described by unique values, but rather by probability distributions. In this study, for the first time, a multivariate statistical model based on Partial Least Squares (PLS was adopted to predict the fuel consumption and costs of six agricultural operations such as: ploughing, harrowing, fertilization, sowing, weed control and shredding. The prediction was conducted on two steps: first of all few initial selected parameters (time per surface-area unit, maximum engine power, purchase price of the tractor and purchase price of the operating machinery were used to estimate the fuel consumption; then the predicted fuel consumption together with the initial parameters were used to estimate the operational costs. Since the obtained models were based on an input dataset very heterogeneous, these resulted to be extremely efficient and so generalizable and robust. In details the results show prediction values in the test with r always ≥ 0.91. Thus, the approach may results extremely useful for both farmers (in terms of economic advantages and at institutional level (representing an innovative and efficient tool for planning future Rural Development Programmes and the Common Agricultural Policy. In light of these advantages the proposed approach may as well be implemented on a web platform and made available to all the stakeholders.
Institute of Scientific and Technical Information of China (English)
WANG Dechang; WU Jingyi; WANG Ruzhu; DOU Weidong
2007-01-01
A novel silica gel-water adsorption chiller consisting of two adsorption/desorption chambers and an evaporator with one heat-pipe working chamber is experimentally studied.The dynamic operating characteristics of the chiller and the thermodynamic characteristics of the adsorber are obtained.The experimental results show that the dynamic operating characteristics of the chiller and the thermodynamic characteristics of the adsorber are satisfactory and that the cycle is a novel and effective adsorption cycle.A mass recovery process increases the cyclic adsorption capacity of the system and improves adaptability of the chiller to a lowgrade heat source.In addition,the experiment indicates that this novel chiller is highly suitable for an air conditioning system with a low dehumidification requirement or a system with a large cycle flowrate and an industrial cooling water system.
Ashyralyev, Allaberen; Tetikoglu, Fatih Sabahattin
2015-09-01
In this study, the Green's function of the second order differential operator Ax defined by the formula Axu =-a (x )ux x(x )+δ u (x ), δ ≥0 , a (x )=a (x +2 π ), x ∈ℝ1 with domain D (Ax)={ u (x ):u (x ),u '(x ),u″(x )∈C (ℝ1),u (x )=u (x +2 π ), x ∈ℝ1,∫0 2 π u (x )d x =0 } is presented. The estimates for the Green's function and it's derivative are obtained. The positivity of the operator Ax is proved.
Sando, Steven K.; Morgan, Timothy J.; Dutton, DeAnn M.; McCarthy, Peter M.
2009-01-01
Charles M. Russell National Wildlife Refuge (CMR) encompasses about 1.1 million acres (including Fort Peck Reservoir on the Missouri River) in northeastern Montana. To ensure that sufficient streamflow remains in the tributary streams to maintain the riparian corridors, the U.S. Fish and Wildlife Service is negotiating water-rights issues with the Reserved Water Rights Compact Commission of Montana. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, conducted a study to gage, for a short period, selected streams that cross CMR, and analyze data to estimate long-term streamflow characteristics for CMR. The long-term streamflow characteristics of primary interest include the monthly and annual 90-, 80-, 50-, and 20-percent exceedance streamflows and mean streamflows (Q.90, Q.80, Q.50, Q.20, and QM, respectively), and the 1.5-, 2-, and 2.33- year peak flows (PK1.5, PK2, and PK2.33, respectively). The Regional Adjustment Relationship (RAR) was investigated for estimating the monthly and annual Q.90, Q.80, Q.50, Q.20, and QM, and the PK1.5, PK2, and PK2.33 for the short-term CMR gaging stations (hereinafter referred to as CMR stations). The RAR was determined to provide acceptable results for estimating the long-term Q.90, Q.80, Q.50, Q.20, and QM on a monthly basis for the months of March through June, and also on an annual basis. For the months of September through January, the RAR regression equations did not provide acceptable results for any long-term streamflow characteristic. For the month of February, the RAR regression equations provided acceptable results for the long-term Q.50 and QM, but poor results for the long-term Q.90, Q.80, and Q.20. For the months of July and August, the RAR provided acceptable results for the long-term Q.50, Q.20, and QM, but poor results for the long-term Q.90 and Q.80. Estimation coefficients were developed for estimating the long-term streamflow characteristics for which the RAR did not provide
Data Service:Characteristics,Market Structure,and the Role of Operator
Institute of Scientific and Technical Information of China (English)
LI Ruo-peng; LU Ting-jie
2005-01-01
To study characteristics and market structure of data service and the role of operator,this paper makes a commercial model by applying the theory of intermediaries and neoclassic economics.Data service has different economic characteristics from voice service.Firstly,production mode of data service is roundabout production,secondly,driving power of data service is economies of specialization,and finally,management method of data service is impersonal management.In data service market,information asymmetry and barrier to entry determine transaction efficiency and the specialization level of service providers indirectly.Therefore,operator should intervene in the market by offering trade service in order to promote development of service providers.Because of different quality of service providers,market structure of data service must be the state that trade platform built by operator and intermediary platform built by operator coexists.
Estimates of the Elastic Characteristics of a Composite with Short Anisotropic Fibers
Zarubin, V. S.; Kuvyrkin, G. N.; Savelyeva, I. Y.
2017-09-01
A composite with chaotically oriented fibers with different elongations and different anisotropy of elastic characteristics is considered. A mathematical model of interaction of such fibers and matrix particles with an isotropic elastic medium whose elastic moduli have to be found as required characteristics of the composite is constructed. The relations derived by the self-consistency method determine the moduli of the composite as functions of the volume concentration, elongations, and elastic properties of each type of fibers, and also of the elastic characteristics of the isotropic matrix. A quantitative analysis of the mathematical model is carried out, and boundaries of the domains of determining parameters within which the effect of fiber elongation is considerable are found. The relations presented allow one to estimate the elastic characteristics of a composite reinforced with various types of short fibers (in particular, high-strength and high-modulus needle-shaped and thread-like crystals, and nanostructural elements).
Energy Technology Data Exchange (ETDEWEB)
Itonaga, M.; Imada, K. [Nippon Steel Corp., Tokyo (Japan); Okada, Y.; Inokuchi, K. [Mitsui SRC Development Co. Ltd., Tokyo (Japan)
1996-10-28
The paper studied a possibility of estimating characteristics of coal liquefaction residue from liquefaction conditions in the case of fixing coal kind in the NEDOL process coal liquefaction PSU. Wyoming coal was used for the study, and the already proposed simplified liquefaction reaction models were used. Among material balances explained by the models, those of asphaltene, preasphaltene, THF insoluble matters are concerned with residue composition. Ash content is separately calculated from ash balance. Reaction velocity constants of simplified liquefaction reaction models which influence the residue composition were obtained by the multiple regression method from experimental results in the past. The estimation expression of residue viscosity was introduced from residue ash/composition. When the residue composition is estimated by the model from liquefaction conditions, and the residue viscosity is obtained using it, the higher the liquefaction temperature is, the higher the residue viscosity is. The result obtained well agreed the measuring result. The simplified liquefaction model of a certain coal kind has been established, and characteristics of residue can be estimated even at liquefaction conditions which have never been experienced before if there is a certain amount of the accumulated data on residue composition/characteristics. 4 refs., 4 figs., 4 tabs.
Directory of Open Access Journals (Sweden)
Danijel Karolyi
2010-01-01
Full Text Available Fermentation characteristics of grass and grass silage at different maturities were studied using in situ and in vitro gas production methods. In situ data determined difference between grass and silage. Degradable fraction decreased as grass matured while the undegradable fraction increased. Rate of degradation (kd was slower for silage than fresh grass. Gas production method (GP data showed that fermentation of degradable fraction was different between stage of maturity in both grass and silage. Other data did not show any difference with the exception for the rate of GP of soluble and undegradable fraction. The in situ degradation characteristics were estimated from GP characteristics. The degradable and undegradable fractions could be estimated by multiple relationships. Using the three-phases model for gas production kd and fermentable organic matter could be estimated from the same parameters. The only in situ parameter that could not be estimated with GP parameters was the soluble fraction. The GP method and the three phases model provided to be an alternative to the in situ method for animal feed evaluations.
Operational characteristics of dual gain single cavity Nd:YVO4 laser
Indian Academy of Sciences (India)
Pranab K Mukhopadhyay; Jogy George; S K Sharma; P K Gupta; T P S Nathan
2002-01-01
Operational characteristics of a dual gain single cavity Nd:YVO4 laser have been investigated. With semiconductor diode laser pump power of 2 W, 800 mW output was obtained with a slope efﬁciency of 49%. Further, by changing the relative orientation of the two crystals the polarization characteristics of the output could be varied. In particular by keeping the two Nd:YVO4 crystals with their -axes orthogonal to each other and adjusting the gain of the crystals so that both operate at approximately the same power level, completely unpolarized beams could be obtained.
Estimation of optimum operating point for thrust magnetic bearing with solid magnet
Institute of Scientific and Technical Information of China (English)
孙首群; 田育民
2003-01-01
A carrying capacity-temperature rise analysis model has been established for analysis of the carrying capacity, temperature rise and carrying capacity-temperature rise characteristic of a thrust magnetic bearing with solid magnet. The results indicate that there must be an optimal operating point for the thrust magnetic beating with solid magnet. The main factors having effect on carrying capacity-temperature rise include static gap and/or ampere-turns. With proper static gap chosen, the bearing can be run near the optimal operating point by adjhusting ampere-turns, thereby optimizing the bearing properties.
Department of Homeland Security — This report presents estimates of the size and characteristics of the resident nonimmigrant population in the United States. The estimates are daily averages for the...
Department of Homeland Security — This report presents estimates of the size and characteristics of the resident nonimmigrant population in the United States. The estimates are daily averages for the...
Characteristic operator functions for quantum input-plant-output models and coherent control
Gough, John E.
2015-01-01
We introduce the characteristic operator as the generalization of the usual concept of a transfer function of linear input-plant-output systems to arbitrary quantum nonlinear Markovian input-output models. This is intended as a tool in the characterization of quantum feedback control systems that fits in with the general theory of networks. The definition exploits the linearity of noise differentials in both the plant Heisenberg equations of motion and the differential form of the input-output relations. Mathematically, the characteristic operator is a matrix of dimension equal to the number of outputs times the number of inputs (which must coincide), but with entries that are operators of the plant system. In this sense, the characteristic operator retains details of the effective plant dynamical structure and is an essentially quantum object. We illustrate the relevance to model reduction and simplification definition by showing that the convergence of the characteristic operator in adiabatic elimination limit models requires the same conditions and assumptions appearing in the work on limit quantum stochastic differential theorems of Bouten and Silberfarb [Commun. Math. Phys. 283, 491-505 (2008)]. This approach also shows in a natural way that the limit coefficients of the quantum stochastic differential equations in adiabatic elimination problems arise algebraically as Schur complements and amounts to a model reduction where the fast degrees of freedom are decoupled from the slow ones and eliminated.
Hydroclimatic Characteristics of the 2012–2015 California Drought from an Operational Perspective
Minxue He; Mitchel Russo; Michael Anderson
2017-01-01
California experienced an extraordinary drought from 2012–2015 (which continues into 2016). This study, from an operational perspective, reviewed the development of this drought in a hydroclimatic framework and examined its characteristics at different temporal and spatial scales. Observed and reconstructed operational hydrologic indices and variables widely used in water resources planning and management at statewide and (hydrologic) regional scales were employed for this purpose. Parsimonio...
A priori estimates for nonvariational operators modeled on Hörmander's vector fields with drift
Directory of Open Access Journals (Sweden)
Marco Bramanti
2013-12-01
Full Text Available For a nonvariational operator structured on Hörmander's vector fields with drift, where the matrix of coffiecients is real, symmetric and uniformly positive, we prove local a priori estimates on the second order derivatives with respect to the vector fields, in Hölder spaces if the coecients are Holder continuous, in Lp spaces if the coefficients are bounded, measurable and locally VMO.
A priori estimates for nonvariational operators modeled on Hörmander's vector fields with drift
Marco Bramanti
2013-01-01
For a nonvariational operator structured on Hörmander's vector fields with drift, where the matrix of coffiecients is real, symmetric and uniformly positive, we prove local a priori estimates on the second order derivatives with respect to the vector fields, in Hölder spaces if the coecients are Holder continuous, in Lp spaces if the coefficients are bounded, measurable and locally VMO.
Willführ, Alper; Brandenberger, Christina; Piatkowski, Tanja; Grothausmann, Roman; Nyengaard, Jens Randel; Ochs, Matthias; Mühlfeld, Christian
2015-12-01
The lung parenchyma provides a maximal surface area of blood-containing capillaries that are in close contact with a large surface area of the air-containing alveoli. Volume and surface area of capillaries are the classic stereological parameters to characterize the alveolar capillary network (ACN) and have provided essential structure-function information of the lung. When loss (rarefaction) or gain (angiogenesis) of capillaries occurs, these parameters may not be sufficient to provide mechanistic insight. Therefore, it would be desirable to estimate the number of capillaries, as it contains more distinct and mechanistically oriented information. Here, we present a new stereological method to estimate the number of capillary loops in the ACN. One advantage of this method is that it is independent of the shape, size, or distribution of the capillaries. We used consecutive, 1 μm-thick sections from epoxy resin-embedded material as a physical disector. The Euler-Poincaré characteristic of capillary networks can be estimated by counting the easily recognizable topological constellations of "islands," "bridges," and "holes." The total number of capillary loops in the ACN can then be calculated from the Euler-Poincaré characteristic. With the use of the established estimator of alveolar number, it is possible to obtain the mean number of capillary loops per alveolus. In conclusion, estimation of alveolar capillaries by design-based stereology is an efficient and unbiased method to characterize the ACN and may be particularly useful for studies on emphysema, pulmonary hypertension, or lung development.
Operating characteristics of heavy loaded cylindrical journal bearing with variable axial profile
Directory of Open Access Journals (Sweden)
Stanislaw Strzelecki
2005-12-01
Full Text Available During the operation of turbounit its bearings displace as a result of heat elongation of bearings supports. It changes the static deflection line of rotor determined during assembly of the turbounit, causing an increase in the stresses on the bearing edges and a decrease in the dynamic state of the machine. One of possibilities to avoid the edge stresses is to apply the bearings with variable axial profile, e.g. hyperboloidal, convex profile in the axial cross-section of bearing. Application of journal bearings with hyperboloidal profile allows to extend the bearing operation range without the stress concentration on the edges of bush. These bearings successfully carry the extreme load in conditions of misaligned axis of journal and the bush eliminating the necessity of using self-aligning bearings. Operating characteristics of bearing include the resulting force, attitude angle, oil film pressure and temperature distributions, minimum oil film thickness, maximum oil film temperature. In literature there is a lack of data on the operating characteristics of heavy loaded hyperboloidal journal bearings operating at the conditions of adiabatic oil film and static equilibrium position of the journal. For the hyperboloidal bearing the operating characteristics have been obtained. Different values of length to diameter ratio, assumed shape and inclination ratio coefficients have been assumed. Iterative solution of the Reynolds', energy and viscosity equations was applied. Adiabatic oil film, laminar flow in the bearing gap as well as aligned and misaligned orientation of journal in the bush were considered.
High-dimensional Sparse Precision Matrix Estimation via Sparse Column Inverse Operator
Liu, Weidong
2012-01-01
This paper proposes a new method for estimating sparse precision matrices in the high dimensional setting. This procedure applies a novel Sparse Column-wise Inverse Operator (SCIO) to modified sample covariance matrices. We establish the convergence rates of this procedure under various matrix norms. Under the Frobenius norm loss, we prove theoretical guarantees on using cross validation to pick data-driven tunning parameters. Another important advantage of this estimator is its efficient computation for large-scale problems, using a path-following coordinate descent algorithm we provide. Numerical merits of our estimator are also illustrated using simulated and real datasets. In particular, this method is found to perform favorably on analyzing an HIV brain tissue dataset and an ADHD resting fMRI dataset.
Estimating Periodic Software Rejuvenation Schedules under Discrete-Time Operation Circumstance
Iwamoto, Kazuki; Dohi, Tadashi; Kaio, Naoto
Software rejuvenation is a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this article, we consider periodic software rejuvenation models based on the expected cost per unit time in the steady state under discrete-time operation circumstance. By applying the discrete renewal reward processes, we describe the stochastic behavior of a telecommunication billing application with a degradation mode, and determine the optimal periodic software rejuvenation schedule minimizing the expected cost. Similar to the earlier work by the same authors, we develop a statistically non-parametric algorithm to estimate the optimal software rejuvenation schedule, by applying the discrete total time on test concept. Numerical examples are presented to estimate the optimal software rejuvenation schedules from the simulation data. We discuss the asymptotic behavior of estimators developed in this paper.
Generazio, Edward R.
2014-01-01
Unknown risks are introduced into failure critical systems when probability of detection (POD) capabilities are accepted without a complete understanding of the statistical method applied and the interpretation of the statistical results. The presence of this risk in the nondestructive evaluation (NDE) community is revealed in common statements about POD. These statements are often interpreted in a variety of ways and therefore, the very existence of the statements identifies the need for a more comprehensive understanding of POD methodologies. Statistical methodologies have data requirements to be met, procedures to be followed, and requirements for validation or demonstration of adequacy of the POD estimates. Risks are further enhanced due to the wide range of statistical methodologies used for determining the POD capability. Receiver/Relative Operating Characteristics (ROC) Display, simple binomial, logistic regression, and Bayes' rule POD methodologies are widely used in determining POD capability. This work focuses on Hit-Miss data to reveal the framework of the interrelationships between Receiver/Relative Operating Characteristics Display, simple binomial, logistic regression, and Bayes' Rule methodologies as they are applied to POD. Knowledge of these interrelationships leads to an intuitive and global understanding of the statistical data, procedural and validation requirements for establishing credible POD estimates.
Cash flows: The Gap Between Reported and Estimated Operating Cash Flow Elements
Directory of Open Access Journals (Sweden)
Mark Hughes
2010-03-01
Full Text Available The FASB and the IASB recently released a joint Discussion Paper “Preliminary Views on FinancialStatement Presentation” (International Accounting Standards Board 2008, which contains a major proposalrequiring companies to report operating cash flows using the direct method and it also requires that theindirect method of calculating operating cash flows be disclosed in the notes. This is a departure from currentrules and has generated considerable debate among respondents’ comment letters on the Discussion Paper.This paper adds to this debate by providing some evidence as to the size of the gap users confront when usingthe indirect method to estimate the major operating cash flow elements, such as cash collected fromcustomers and cash paid to suppliers. Using a sample of Australian companies which reported operating cashflows using the direct method, and presented the indirect method in the notes, we find significant differencesbetween reported and estimated figures for both cash collected from customers and cash paid to suppliers.These findings support the discussion paper’s proposal that companies be required to report cash flows usingboth the direct and indirect methods.
Estimation of the laser cutting operating cost by support vector regression methodology
Jović, Srđan; Radović, Aleksandar; Šarkoćević, Živče; Petković, Dalibor; Alizamir, Meysam
2016-09-01
Laser cutting is a popular manufacturing process utilized to cut various types of materials economically. The operating cost is affected by laser power, cutting speed, assist gas pressure, nozzle diameter and focus point position as well as the workpiece material. In this article, the process factors investigated were: laser power, cutting speed, air pressure and focal point position. The aim of this work is to relate the operating cost to the process parameters mentioned above. CO2 laser cutting of stainless steel of medical grade AISI316L has been investigated. The main goal was to analyze the operating cost through the laser power, cutting speed, air pressure, focal point position and material thickness. Since the laser operating cost is a complex, non-linear task, soft computing optimization algorithms can be used. Intelligent soft computing scheme support vector regression (SVR) was implemented. The performance of the proposed estimator was confirmed with the simulation results. The SVR results are then compared with artificial neural network and genetic programing. According to the results, a greater improvement in estimation accuracy can be achieved through the SVR compared to other soft computing methodologies. The new optimization methods benefit from the soft computing capabilities of global optimization and multiobjective optimization rather than choosing a starting point by trial and error and combining multiple criteria into a single criterion.
Kessner, A; Burnett, R W; Bowers, G N
1981-07-01
The Beckman ASTRA is a microprocessor-controlled multichannel chemistry analyzer. The output of each module is available to the operator as analog-to-digital conversion (ADC) numbers, which we record during each calibration (Response Monitoring). After so studying three instruments for a total of 33 months, we have established limits for Calibrator ADC numbers that indicate possible operator action (Action Limits). These Action Limits are tighter than the microprocessor's programmed limits, and alert the operator to short- and long-term drift. These tighter limits warn of (a) impending failure of the instrument to calibrate or (b) possible inaccuracies in results for patients. We have instituted changes in preventive maintenance based on our studies of each module's operational characteristics, and have replaced electrodes that failed to meet our Response Monitoring specifications. Response Monitoring and Action Limits based upon ADC numbers have significantly enhanced our understanding of the ASTRA system and thus improved its operational efficiency and analytical reliability. Estimates of precision and accuracy (true value) were satisfactory in comparison to our prior single-channel continuous-flow and flame photometry analytical measurement systems.
Estimates of geothermal reservoir fluid characteristics: GeoSys.Chem and WATCH
Ignacio Salvador Torres-Alvarado; Mahendra P. Verma; Kizito Opondo; David Nieva; Füsun Tut Haklidir; Edgar Santoyo; Rosa María Barragán; Víctor Arellano
2012-01-01
A comparative study of the reservoir fluid characteristics calculation of ten production wells of Los Azufres, Los Humeros and Cerro Prieto geothermal fields using two computer codes GeoChem (GeoSys.Chem) and WATCH is presented. GeoSys.Chem estimates the reservoir temperature and vapor fraction through quartz geothermometry and assuming enthalpy conservation, while the average temperature of quartz and Na/K geothermometers is employed in WATCH and vapor fraction is also calculated through ent...
Differential Characteristics and Methods of Operation Underlying CAI/CMI Drill and Practice Systems.
Hativa, Nira
1988-01-01
Describes computer systems that combine drill and practice instruction with computer-managed instruction (CMI) and identifies system characteristics in four categories: (1) hardware, (2) software, (3) management systems, and (4) methods of daily operation. Topics discussed include microcomputer networks, graphics, feedback, degree of learner…
Employing the therapeutic operating characteristic (TOC) graph for individualised dose prescription
Hoffmann, A.L.; Huizenga, H.; Kaanders, J.H.A.M.
2013-01-01
BACKGROUND: In current practice, patients scheduled for radiotherapy are treated according to 'rigid' protocols with predefined dose prescriptions that do not consider risk-taking preferences of individuals. The therapeutic operating characteristic (TOC) graph is applied as a decision-aid to assess
Receiver operating characteristics of perceptrons : Influence of sample size and prevalence
Freking, Ansgar; Biehl, Michael; Braun, Christian; Kinzel, Wolfgang; Meesmann, Malte
1999-01-01
In many practical classification problems it is important to distinguish false positive from false negative results when evaluating the performance of the classifier. This is of particular importance for medical diagnostic tests. In this context, receiver operating characteristic (ROC) curves have b
Energy efficiency estimation of a steam powered LNG tanker using normal operating data
Directory of Open Access Journals (Sweden)
Sinha Rajendra Prasad
2016-01-01
Full Text Available A ship’s energy efficiency performance is generally estimated by conducting special sea trials of few hours under very controlled environmental conditions of calm sea, standard draft and optimum trim. This indicator is then used as the benchmark for future reference of the ship’s Energy Efficiency Performance (EEP. In practice, however, for greater part of operating life the ship operates in conditions which are far removed from original sea trial conditions and therefore comparing energy performance with benchmark performance indicator is not truly valid. In such situations a higher fuel consumption reading from the ship fuel meter may not be a true indicator of poor machinery performance or dirty underwater hull. Most likely, the reasons for higher fuel consumption may lie in factors other than the condition of hull and machinery, such as head wind, current, low load operations or incorrect trim [1]. Thus a better and more accurate approach to determine energy efficiency of the ship attributable only to main machinery and underwater hull condition will be to filter out the influence of all spurious and non-standard operating conditions from the ship’s fuel consumption [2]. The author in this paper identifies parameters of a suitable filter to be used on the daily report data of a typical LNG tanker of 33000 kW shaft power to remove effects of spurious and non-standard ship operations on its fuel consumption. The filtered daily report data has been then used to estimate actual fuel efficiency of the ship and compared with the sea trials benchmark performance. Results obtained using data filter show closer agreement with the benchmark EEP than obtained from the monthly mini trials . The data filtering method proposed in this paper has the advantage of using the actual operational data of the ship and thus saving cost of conducting special sea trials to estimate ship EEP. The agreement between estimated results and special sea trials EEP is
Gladshteyn, V. I.; Troitskiy, A. I.
2017-01-01
Research of a metal of the stop valve case (SVC) of the K-300-23.5 LMZ turbine (steel grade 15Kh1M1FL), destroyed after operation for 331000 hours, is performed. It's chemical composition and properties are determined as follows: a short-term mechanical tensile stress at 20°C and at elevated temperature, critical temperature, fragility, critical crack opening at elevated temperature, and long-term strength. Furthermore, nature of the microstructure, packing density of carbide particles and their size, and chemical composition of carbide sediment are estimated. A manifestation of metal properties for the main case components by comparison with a forecast of the respective characteristics made for the operating time of 331000 hours is tested. Property-time relationships are built for the forecast using statistical treatment of the test results for the samples cut out from more than 300 parts. Representativeness of the research results is proved: the statistical treatment of their differences are within the range of ±5%. It has been found that, after 150000 hours of operation, only the tensile strength insignificantly depends on the operating time at 20°C, whereas indicators of strength at elevated temperature significantly reduce, depending on the operating time. A brittle-to-ductile transition temperature (BDTT) raises, a critical notch opening changes in a complicated way, a long-term strength reduces. It has been found empirically that the limit of a long-term strength of the SVC metal at 540°C and the operating time of 105 hours is almost 1.6 times less than the required value in the as-delivered state. It is possible to evaluate a service life of the operating valves with the operating time of more than 330000 hours with respect to the long-term strength of the metal taking into account the actual temperature and stress. Guidelines for the control of similar parts are provided.
Estimating small area health-related characteristics of populations: a methodological review
Directory of Open Access Journals (Sweden)
Azizur Rahman
2017-05-01
Full Text Available Estimation of health-related characteristics at a fine local geographic level is vital for effective health promotion programmes, provision of better health services and population-specific health planning and management. Lack of a micro-dataset readily available for attributes of individuals at small areas negatively impacts the ability of local and national agencies to manage serious health issues and related risks in the community. A solution to this challenge would be to develop a method that simulates reliable small-area statistics. This paper provides a significant appraisal of the methodologies for estimating health-related characteristics of populations at geographical limited areas. Findings reveal that a range of methodologies are in use, which can be classified as three distinct set of approaches: i indirect standardisation and individual level modelling; ii multilevel statistical modelling; and iii micro-simulation modelling. Although each approach has its own strengths and weaknesses, it appears that microsimulation- based spatial models have significant robustness over the other methods and also represent a more precise means of estimating health-related population characteristics over small areas.
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
Soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics fromparticle-size distribution data. Predictive capabilities of three fractal models, i.e, Tyler-Wheatcraft model,Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental datafrom an international database and literature. Particle-size distribution data were firstly interpolated into20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the poresurface were then calculated from the detailed particle-size distribution and incorporated as a parameter infractal water retention models. Comparisons between measured and model-estimated water retention cha-racteristics indicated that these three models were applicable to relatively different soil textures and pressurehead ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- andmedium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of watercontents at low pressure heads than at high pressure heads.
Estimation of Soil-Water Characteristic Curves in Multiple-Cycles Using Membrane and TDR System
Directory of Open Access Journals (Sweden)
Won-Taek Hong
2016-12-01
Full Text Available The objective of this study is to estimate multiple-cycles of the soil-water characteristic curve (SWCC using an innovative volumetric pressure plate extractor (VPPE, which is incorporated with a membrane and time domain reflectometry (TDR. The pressure cell includes the membrane to reduce the experimental time and the TDR probe to automatically estimate the volumetric water content. For the estimation of SWCC using the VPPE system, four specimens with different grain size and void ratio are prepared. The volumetric water contents of the specimens according to the matric suction are measured by the burette system and are estimated in the TDR system during five cycles of SWCC tests. The volumetric water contents estimated by the TDR system are almost identical to those determined by the burette system. The experimental time significantly decreases with the new VPPE. The hysteresis in the SWCC is largest in the first cycle and is nearly identical after 1.5 cycles. As the initial void ratio decreases, the air entry value increases. This study suggests that the new VPPE may effectively estimate multiple-cycles of the SWCC of unsaturated soils.
Variability of exposure and estimation of cumulative exposure in a manually operated coal mine
Energy Technology Data Exchange (ETDEWEB)
Mamuya, S.H.D.; Bratveit, M.; Mwaiselage, J.; Moen, B.E. [University of Bergen, Bergen (Norway). Center for International Health
2006-10-15
This study aims at estimating variability in exposure to respirable dust and assessing whether the a priori grouping by job team is appropriate for an exposure-response study on respiratory effects among workers in a manually operated coal mine in Tanzania. Furthermore, estimated exposure levels were used to calculate cumulative exposure. Full-shift personal respirable dust samples (n = 204) were collected from 141 randomly chosen workers at underground and surface work sites. The geometric mean exposure for respirable dust varied from 0.07 mg m{sup -3} for office workers to 1.96 mg m{sup -3} for the development team. The analogous range of respirable quartz exposure was 0.006-0.073 mg m{sup -3}. Variance components were estimated using random effect models. For most job teams the within-worker variance component was considerably higher than the between-worker variance component. For respirable dust the estimated attenuation of the linear exposure-response relationship was low (5.9%) when grouping by job team. Grouping by job team was considered appropriate for studying the association between current dust exposure and respiratory effects. Based on the estimated worker-specific mean exposure in the job teams, the arithmetic mean cumulative exposure for the 299 workers who participated in the epidemiological part of the study was 38.1 mg. yr m{sup -3} for respirable dust and 2.0 mg. yr m{sup -3} for quartz.
The Estimation of Snow Damages considering the Topographical Characteristics in South Korea
Chung, G.; Kwon, S. H.; Kim, J.; Yeongrock, O.
2016-12-01
The property damages and loss of lives caused by the natural disasters has been increased. The global warming and climate change are considered as one of the most accelerating factors. In South Korea, the most severe damages have been caused by heavy rainfall and/or typhoon. However, the heavy snow damages are also increased recently. From 1993 and 2002, 7.6% of the property damage caused by natural disasters was induced by snow. For example, in March 2004, the substantial property damages were occurred by heavy snow in Chungcheong province. And, gymnastic building was collapsed by heavy snow and 10 people were died in 2014. In the future, more severe damage could be happened under the climate change scenarios. Therefore, it is very important to prepare snow disaster and mitigate damages. However, it is difficult to estimate accurate damage due to the complexity of snow physics and the lack of data. Therefore, more reliable damage estimation technique is required for the more effective disaster response and management. In this study, the topographical characteristics of South Korea were analyzed with respect to the design code for the greenhouses, animal farm, and fish farm that are the most vulnerable buildings under the heavy snow condition. The property damage caused by snow was estimated using multiple regression analysis using the historical damage data and the topographical characteristics. The developed model could be applied to estimate the snow damage as early as the amount of snow is forecasted in a region to prepare the disaster response.
Lagroix, Hayley E P; Yanko, Matthew R; Spalek, Thomas M
2012-07-01
Many cognitive and perceptual phenomena, such as iconic memory and temporal integration, require brief displays. A critical requirement is that the image not remain visible after its offset. It is commonly believed that liquid crystal displays (LCD) are unsuitable because of their poor temporal response characteristics relative to cathode-ray-tube (CRT) screens. Remarkably, no psychophysical estimates of visible persistence are available to verify this belief. A series of experiments in which white stimuli on a black background produced discernible persistence on CRT but not on LCD screens, during both dark- and light-adapted viewing, falsified this belief. Similar estimates using black stimuli on a white background produced no visible persistence on either screen. That said, photometric measurements are available that seem to confirm the poor temporal characteristics of LCD screens, but they were obtained before recent advances in LCD technology. Using current LCD screens, we obtained photometric estimates of rise time far shorter (1-6 ms) than earlier estimates (20-150 ms), and approaching those of CRTs (<1 ms). We conclude that LCDs are preferable to CRTs when visible persistence is a concern, except when black-on-white displays are used.
Pose estimation quality assessment for intra-operative image guidance systems
Egli, Adrian; Kleinszig, Gerhard; John, Adrian; Fernandez, Alberto; Cardelino, Juan
2013-03-01
In trauma and orthopedic surgery screw assessment and trajectory prediction using two-dimensional X-ray images is very difficult due to projected 3D information. However screw assessment can be done with multiple X-ray images. If the X-ray image contains the projected implant geometry it can be used as global coordinate reference. Thereby multiple independent X-ray images can be synchronized by estimating the implant pose in each single image. Consequently high accuracy pose estimation is fundamental. To measure the outcome quality an evaluation process has been designed. The evaluation process investigates in its first step several clinical intra-operative anterior-posterior (AP) and medio-lateral (ML) X-ray images which have been analyzed using a manual pose estimation method. With the manual method the six 3D parameters of the implant pose are estimated. These parameters define as well the camera pose relative to the implant. Based on the pose parameters of all clinical cases the capturing range for typical AP and ML images is statistically defined. The implant was attached to a phantom with 16 steel balls which allows to calculate the ground truth pose. Afterwards several X-ray images of the phantom are taken within the statistically defined capturing range. With the known ground truth different pose estimation methods can be compared. For each method the estimation quality can be calculated. In addition this error calculation can be used to adjust the initial manually determined capturing range. This paper explains the error evaluation process and describes how to validate pose estimation methods for clinical applications.
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-09-01
The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. This volume represents the total estimated costs for the W113 facility. Operating Contractor Management costs have been incorporated as received from WHC. The W113 Facility TEC is $19.7 million. This includes an overall project contingency of 14.4% and escalation of 17.4%. A January 2001 construction contract procurement start date is assumed.
Knudsen, Elisabet; Maltese, Giovanni; Tarnow, Peter; Tovetjärn, Robert; Kölby, Lars
2012-09-01
Impaired psychological development in children with single suture craniosynostosis is often described in the literature. The authors' own experience was that these children appeared to have normal psychological development during their first years of life. The aim of the present study was, therefore, to evaluate if parental estimation would reveal any shortcomings in psychological development. All consecutive patients operated on for non-syndromal single suture synostosis between October 2002 and June 2006 were included (n = 66). A questionnaire was filled out by the parents when the child was 3 years old. The questions concerned development of speech, motor control, personal abilities, and emotional development. The results were compared with randomly selected controls of the same age (n = 180) whose parents answered the same questionnaire. The results showed that children operated on for single suture synostosis did not show any signs of lasting disadvantages due to craniofacial surgery. The children did not in any respect suffer from a hampered psychological development up to 3 years of age. In summary the psychological development of patients operated on for single suture synostosis seems to be normal up to 3 years of age as far as parental estimation can reveal.
A study on operators' cognitive response characteristics to the computerized working environment
Energy Technology Data Exchange (ETDEWEB)
Lee, Yong Hee; Lee, Jang Soo; Suh, Sang Moon; Lee, Hyun Cheol; Jung, Kwang Tae; Lee, Dhong Ha
1998-12-01
Although the introduction of computerized working environment to the nuclear facilities, the study on the human factors impacts of computers and automation has not been enough like the other industries. It is necessary to prepare the way to cope with the negative aspects in spite of many positive aspects of computerization in nuclear. This study is an empirical study including the survey of the human factor concerning, especially to the cognitive response of operators' and the experiments on the error proneness. At first, we survey the design and its changes of operator interface and interaction in nuclear power plants, and conclude five human factor issues. We discuss situation awareness issues as one of the major human factor concerning, and the assessment method. Secondly, a questionnaire and interviews survey to the operator's response characteristics are performed for possible criterion measures to the in-depth study on the cognitive characteristics. Finally, several experiments are conducted to test the error proneness. The issues and findings of this study could be utilized to any further study on the cognitive characteristic of operators to the computerized work environment.
Estimation of intra-operative brain shift based on constrained Kalman filter.
Shakarami, M; Suratgar, A A; Talebi, H A
2015-03-01
In this study, the problem of estimation of brain shift is addressed by which the accuracy of neuronavigation systems can be improved. To this end, the actual brain shift is considered as a Gaussian random vector with a known mean and an unknown covariance. Then, brain surface imaging is employed together with solutions of linear elastic model and the best estimation is found using constrained Kalman filter (CKF). Moreover, a recursive method (RCKF) is presented, the computational cost of which in the operating room is significantly lower than CKF, because it is not required to compute inverse of any large matrix. Finally, the theory is verified by the simulation results, which show the superiority of the proposed method as compared to one existing method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.
Projected metastable Markov processes and their estimation with observable operator models
Energy Technology Data Exchange (ETDEWEB)
Wu, Hao, E-mail: hao.wu@fu-berlin.de; Prinz, Jan-Hendrik, E-mail: jan-hendrik.prinz@fu-berlin.de; Noé, Frank, E-mail: frank.noe@fu-berlin.de [DFG Research Center Matheon, Free University Berlin, Arnimallee 6, 14195 Berlin (Germany)
2015-10-14
The determination of kinetics of high-dimensional dynamical systems, such as macromolecules, polymers, or spin systems, is a difficult and generally unsolved problem — both in simulation, where the optimal reaction coordinate(s) are generally unknown and are difficult to compute, and in experimental measurements, where only specific coordinates are observable. Markov models, or Markov state models, are widely used but suffer from the fact that the dynamics on a coarsely discretized state spaced are no longer Markovian, even if the dynamics in the full phase space are. The recently proposed projected Markov models (PMMs) are a formulation that provides a description of the kinetics on a low-dimensional projection without making the Markovianity assumption. However, as yet no general way of estimating PMMs from data has been available. Here, we show that the observed dynamics of a PMM can be exactly described by an observable operator model (OOM) and derive a PMM estimator based on the OOM learning.
Sundaram, Meenakshi
2005-01-01
NASA and the aerospace industry are extremely serious about reducing the cost and improving the performance of launch vehicles both manned or unmanned. In the aerospace industry, sharing infrastructure for manufacturing more than one type spacecraft is becoming a trend to achieve economy of scale. An example is the Boeing Decatur facility where both Delta II and Delta IV launch vehicles are made. The author is not sure how Boeing estimates the costs of each spacecraft made in the same facility. Regardless of how a contractor estimates the cost, NASA in its popular cost estimating tool, NASA Air force Cost Modeling (NAFCOM) has to have a method built in to account for the effect of infrastructure sharing. Since there is no provision in the most recent version of NAFCOM2002 to take care of this, it has been found by the Engineering Cost Community at MSFC that the tool overestimates the manufacturing cost by as much as 30%. Therefore, the objective of this study is to develop a methodology to assess the impact of infrastructure sharing so that better operations cost estimates may be made.
Crampton, Lisa H.; Brinck, Kevin W.; Pias, Kyle E.; Heindl, Barbara A. P.; Savre, Thomas; Diegmann, Julia S.; Paxton, Eben
2017-01-01
Accurate estimates of the distribution and abundance of endangered species are crucial to determine their status and plan recovery options, but such estimates are often difficult to obtain for species with low detection probabilities or that occur in inaccessible habitats. The Puaiohi (Myadestes palmeri) is a cryptic species endemic to Kauaʻi, Hawai‘i, and restricted to high elevation ravines that are largely inaccessible. To improve current population estimates, we developed an approach to model distribution and abundance of Puaiohi across their range by linking occupancy surveys to habitat characteristics, territory density, and landscape attributes. Occupancy per station ranged from 0.17 to 0.82, and was best predicted by the number and vertical extent of cliffs, cliff slope, stream width, and elevation. To link occupancy estimates with abundance, we used territory mapping data to estimate the average number of territories per survey station (0.44 and 0.66 territories per station in low and high occupancy streams, respectively), and the average number of individuals per territory (1.9). We then modeled Puaiohi occupancy as a function of two remote-sensed measures of habitat (stream sinuosity and elevation) to predict occupancy across its entire range. We combined predicted occupancy with estimates of birds per station to produce a global population estimate of 494 (95% CI 414–580) individuals. Our approach is a model for using multiple independent sources of information to accurately track population trends, and we discuss future directions for modeling abundance of this, and other, rare species.
1999-01-01
This paper describes a pre-flight estimation method for aerodynamic characteristics and investigates the accuracy of the estimated aerodynamic characteristics of the scaled supersonic experimental airplane, using IMU (Inertial Measurement Unit) data obtained in a flight simulation. The results demonstrate that the required accuracy is not achieved and that the main sources of error are in the estimation of dynamic pressure, misalignment between the body axis and IMU chassis axis, and IMU disc...
E2CAV, Pavement layer thickness estimation system based on image texture operators
Directory of Open Access Journals (Sweden)
Brayan Barrios Arcila
2017-01-01
Full Text Available Context: Public roads are an essential part of economic progress in any country; they are fundamental for increasing the efficiency on transportation of goods and are a remarkable source of employment. For its part, Colombia has few statistics on the condition of its roads; according with INVIAS the state of the roads in Colombia can be classified as “Very Good” (21.1%, “Good” (34.7%, and “Regular” or “Bad” (43.46%. Thus, from the point of view of pavement rehabilitation, it is worth securing the quality of those roads classified as “Regular” or “Bad”. Objective: In this paper we propose a system to estimate the thickness of the pavement layer using image segmentation methods. The pavement thickness is currently estimated using radars of terrestrial penetration, extraction of cores or making pips; and it is part of structural parameters in the systems of evaluation of pavement. Method: The proposed system is composed of a vertical movement control unit, which introduces a video scope into a small hole in the pavement, then the images are obtained and unified in a laptop. Finally, this mosaic is processed through texture operators to estimate the thickness of the pavement. Users can select between the Otsu method and Gabor filters to process the image data. Results: The results include laboratory and field tests; these tests show errors of 5.03% and 11.3%, respectively, in the thickness of the pavement. Conclusion: The proposed system is an attractive option for local estimation of pavement thickness, with minimal structural damage and less impact on mobility and number of operators.
Mekhaimr, Sayed A.
2017-06-01
The study of the prevailing atmospheric conditions is an essential part of any site testing for a new telescope establishment. In this article, the meteorological parameters that affect the astronomical seeing at St. Catherine region, where a two candidate sites are located, are studied based on the available climate data. The complex topographical features of the region cause some differences between the weather at the nearest meteorological station and that at the candidate sites. This issue is illustrated through high resolution atmospheric modeling for short period (six days) as a case study. Finally, a preliminary estimation of operational hours for the telescope at the candidate sites is calculated.
Fleet size estimation for spreading operation considering road geometry, weather and traffic
Directory of Open Access Journals (Sweden)
Steven I-Jy Chien
2014-02-01
Full Text Available Extreme weather conditions(i.e. snow storm in winter time have caused significant travel disruptions and increased delay and traffic accidents. Snow plowing and salt spreading are the most common counter-measures for making our roads safer for motorists. To assist highway maintenance authorities with better planning and allocation of winter maintenance resources, this study introduces an analytical model to estimate the required number of trucks for spreading operation subjective to pre-specified service time constraints considering road geometry, weather and traffic. The complexity of the research problem lies in dealing with heterogeneous road geometry of road sections, truck capacities, spreading patterns, and traffic speeds under different weather conditions and time periods of an event. The proposed model is applied to two maintenance yards with seven road sections in New Jersey (USA, which demonstrates itself fairly practical to be implemented, considering diverse operational conditions.
Nonlinear analysis of gravity signals based on estimating attractor topological characteristics
Minervina, H.
2003-04-01
The nonlinear dynamical systems (NDSs) and processes with self-organization named as complex systems[1] are investi- gated with great activity in last decades.The gravity phe- nomenon can be also interpreted from the point of view of the self-organization theory first of all as primary irre- versible process [1].The NDS behavior are described on the basis of reconstruction of its attractor in m-dimensional Euclidean state-space and estimation of attractor topolo- gical characteristics(including minimal embedding dimension, scaling factors etc). With this aim it is necessary to select the state-space with the minimal dimension m* as the value m* is an upper limit of the degrees of freedom for a system. The determing m* on the basis of various correlative topological methods requires large computer expenditures [2]. Such methods have essential computational complexity and demand long time series (N is approximatly equal to 10000 - 100000 points) for their implementation. The method proposed in [3]-[5] allows to reduce the compu- tational complexity. However,the proposed locally topolo- gical method has especially heuristic character.This paper gives the theoretical ground of a local-topological method for defining minimal attractor embedding dimension on the basis of proposed matrix series into the state-space [6]. This method requires much less experimental data and is stable to changing m* [3],[5].The investigation of digital gravity signals using local-topological analysis of chaotic attractor trajectories is carried out. For this case we use the geodynamic ground of monotoring for observing variations of gravity field of the Earth on the base of quartz gravi- meters as GNU-KS. The computer confirmation of the theore- tical results is presented. References [1] G.Nicolis and I.Prigogine. Exploring Complexity. W.H.Freeman and Co., New York, 1989. [2] P.Grassberger and I. Procaccia,Characterization of strange attractors, Phys. Rev.Lett. vol.50, 346-349,1983. [3] V
Directory of Open Access Journals (Sweden)
Ćalasan Martin P.
2013-01-01
Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.
Directory of Open Access Journals (Sweden)
Bin Deng
2013-01-01
Full Text Available Parabolic-reflector antennas (PRAs, usually possessing rotation, are a particular type of targets of potential interest to the synthetic aperture radar (SAR community. This paper is aimed to investigate PRA’s scattering characteristics and then to extract PRA’s parameters from SAR returns, for supporting image interpretation and target recognition. We at first obtain both closed-form and numeric solutions to PRA’s backscattering by geometrical optics (GO, physical optics, and graphical electromagnetic computation, respectively. Based on the GO solution, a migratory scattering center model is at first presented for representing the movement of the specular point with aspect angle, and then a hybrid model, named the migratory/micromotion scattering center (MMSC model, is proposed for characterizing a rotating PRA in the SAR geometry, which incorporates PRA’s rotation into its migratory scattering center model. Additionally, we in detail analyze PRA’s radar characteristics on radar cross-section, high-resolution range profiles, time-frequency distribution, and 2D images, which also confirm the models proposed. A maximal likelihood estimator is developed for jointly solving the MMSC model for PRA’s multiple parameters by optimization. By exploiting the aforementioned characteristics, the coarse parameter estimation guarantees convergency upon global minima. The signatures recovered can be favorably utilized for SAR image interpretation and target recognition.
Christensen, R.C.; Johnson, E.B.; Plantz, G.G.
1986-01-01
Methods are presented for estimating 10 streamflow characteristics at three types of sites on natural flow streams in the Colorado River Basin in Utah. The streamflow characteristics include average discharge and annual maximum 1-, 7-, and 15-day mean discharges for recurrence intervals of 10, 50 and 100 years. At or near gaged sites, two methods weight gaging station data with regression equation values to estimate streamflow characteristics. At sites on ungaged streams, a method estimates streamflow characteristics using regression equations. The regression equations relate the streamflow characteristics to the following basin and climatic characteristics: contributing drainage area, mean basin elevation, mean annual precipitation, main channel slope, and forested area. Separate regression equations were developed for four hydrologically distinct regions in the study area. The standard error of estimate for the 10 streamflow characteristics ranges from 13% to 87%. Basin, climatic, and streamflow characteristics, available as of September 30, 1981, are presented for 135 gaging stations in Utah, Arizona, Colorado, and Wyoming. In addition, weighted estimates of the streamflow characteristics based on station data and the regression equation estimates are provided for most gaging stations. (Author 's abstract)
RELATIONS OF DERIVATIVE ALGEBRA AND RING OF DIFFERENTIAL OPERATORS IN CHARACTERISTIC p>0
Institute of Scientific and Technical Information of China (English)
张江峰
2002-01-01
Let K be a field of characteristic p>0. We prove that the derivative algebra of K[x1,…,xn] is a proer subring of the ring of differential operators of K[x1,…,xn]. A concrete example is given to show that there is a differential operator of order p that does not belong to the derivative algebra. By these results, is follows that the derivative algebra is Morita equivalent to K[xp1,…,xpn], and hence its global homological dimension, Krull dimension, K0 group and some other properties are got.
IMPROVEMENT OF OPERATIONAL CHARACTERISTICS OF THE AIRCRAFT WITH A DEFORMABLE COMBINED WING
Zinchenko, Dmytro; Ortamevzi, Gurkan
2015-01-01
In this article studied the characteristics of the experimental and numerical models, as well as a comparative analysis of performance of flying machines with different types of bearing surfaces with equal specific wing loading G / S.Development of experimental aircrafts with soft wings due to the need to increase the operation of aircrafts.The results of wind tunnel test has performed using a general purpose classical scheme for models plane (Aeroprakt A-20) and are provided with two differ...
Characteristics of operations at fish-landing sites managed by private owners in Thailand
Yoshimura, Mika; Okamoto, Junichiro; Yasuma, Hiroki; Kimura, Nobuo
2016-01-01
This study presents the results of a survey on the operation characteristics of landing sites managed by private owners in Thailand. The survey was conducted by interviewing private landing site owners, managers of fishery cooperatives, middlemen, and fishers. The results of interviews were summarized with respect to scale of business, fisheries, transaction, types of people associated with landing sites, location, and daily schedule. Landing sites were located along canals in coastal provinc...
Application of the Characteristic Time Expansion Method for Estimating Nonlinear Restoring Forces
Directory of Open Access Journals (Sweden)
Yung-Wei Chen
2013-01-01
Full Text Available This paper proposes a characteristic time expansion method (CTEM for estimating nonlinear restoring forces. Because noisy data and numerical instability are the main causes of numerical developing problems in an inverse field, a polynomial to identify restoring forces is usually adopted to eliminate these problems. However, results of the way doing are undesirable for a high order of polynomial. To overcome this difficulty, the characteristic length (CL is introduced into the power series, and a natural regularization technique is applied to ensure numerical stability and determine the existence of a solution. As compared to previous solutions presented in other researches, the proposed method is a desirable and accurate solver for the problem of restoring the force in the inverse vibration problems.
The application of interval calculus in estimation of dynamic characteristics of structures
Directory of Open Access Journals (Sweden)
Đorđević Đorđe
2012-01-01
Full Text Available The paper analyzed application of interval calculus in estimation of dynamic characteristics of linear systems. The eigen periods of oscillation of structures are affected by several parameters: geometrical characteristics of cross sections of members, magnitude of the mass concentrated in the floors and modulus of elasticity of materials. As a numerical example, the frame reinforced concrete structure was taken, for which the mentioned parameters are given in the form interval. The result is also obtained in the form of interval so it is possible to observe the direct effects on the value of the structural oscillation periods by changing one or several parameters. [Projekat Ministarstva nauke Republike Srbije, br. TR36016: Experimental and theoretical investigation of frames and plates with semi-rigid connections from the view of the second order theory and stability analysis i br. TR36028: Development and improvement of methods for analyses of soil-structure interaction based on theoretical and experimental research
Directory of Open Access Journals (Sweden)
Mohammad H. Radfar
2006-11-01
Full Text Available We present a new technique for separating two speech signals from a single recording. The proposed method bridges the gap between underdetermined blind source separation techniques and those techniques that model the human auditory system, that is, computational auditory scene analysis (CASA. For this purpose, we decompose the speech signal into the excitation signal and the vocal-tract-related filter and then estimate the components from the mixed speech using a hybrid model. We first express the probability density function (PDF of the mixed speech's log spectral vectors in terms of the PDFs of the underlying speech signal's vocal-tract-related filters. Then, the mean vectors of PDFs of the vocal-tract-related filters are obtained using a maximum likelihood estimator given the mixed signal. Finally, the estimated vocal-tract-related filters along with the extracted fundamental frequencies are used to reconstruct estimates of the individual speech signals. The proposed technique effectively adds vocal-tract-related filter characteristics as a new cue to CASA models using a new grouping technique based on an underdetermined blind source separation. We compare our model with both an underdetermined blind source separation and a CASA method. The experimental results show that our model outperforms both techniques in terms of SNR improvement and the percentage of crosstalk suppression.
Directory of Open Access Journals (Sweden)
Dansereau Richard M
2007-01-01
Full Text Available We present a new technique for separating two speech signals from a single recording. The proposed method bridges the gap between underdetermined blind source separation techniques and those techniques that model the human auditory system, that is, computational auditory scene analysis (CASA. For this purpose, we decompose the speech signal into the excitation signal and the vocal-tract-related filter and then estimate the components from the mixed speech using a hybrid model. We first express the probability density function (PDF of the mixed speech's log spectral vectors in terms of the PDFs of the underlying speech signal's vocal-tract-related filters. Then, the mean vectors of PDFs of the vocal-tract-related filters are obtained using a maximum likelihood estimator given the mixed signal. Finally, the estimated vocal-tract-related filters along with the extracted fundamental frequencies are used to reconstruct estimates of the individual speech signals. The proposed technique effectively adds vocal-tract-related filter characteristics as a new cue to CASA models using a new grouping technique based on an underdetermined blind source separation. We compare our model with both an underdetermined blind source separation and a CASA method. The experimental results show that our model outperforms both techniques in terms of SNR improvement and the percentage of crosstalk suppression.
Time-Delay Estimation using the Characteristic Roots of Delay Differential Equations
Directory of Open Access Journals (Sweden)
Sun Yi
2012-01-01
Full Text Available Problem statement: For ordinary dynamic systems (i.e., non-delayed, various methods such as linear least-squares, gradient-weighted least-squares, Kalman filtering and other robust techniques have been widely used in signal processing, robotics, civil engineering. On the other hand, time-delay estimation of systems with unknown time-delay is still a challenging problem due to difficulty in formulation caused. Approach: The presented method makes use of the Lambert W function and analytical solutions of scalar first-order Delay Differential Equations (DDEs. The Lambert W function has been known to be useful in solving delay differential equations. From the solutions in terms of the Lambert W function, the dominant characteristic roots can be obtained and used to estimate time-delays. The function is already embedded in various software packages (e.g., MATLAB and thus, the presented method can be readily used for time-delay systems. Results: The presented method and the provided examples show ease of formulation and accuracy of time-delay estimation. Conclusion: Estimation of time-delays can be conducted in an analytical way. The presented method will be extended to general systems of DDEs and application to physical systems.
3D global estimation and augmented reality visualization of intra-operative X-ray dose.
Rodas, Nicolas Loy; Padoy, Nicolas
2014-01-01
The growing use of image-guided minimally-invasive surgical procedures is confronting clinicians and surgical staff with new radiation exposure risks from X-ray imaging devices. The accurate estimation of intra-operative radiation exposure can increase staff awareness of radiation exposure risks and enable the implementation of well-adapted safety measures. The current surgical practice of wearing a single dosimeter at chest level to measure radiation exposure does not provide a sufficiently accurate estimation of radiation absorption throughout the body. In this paper, we propose an approach that combines data from wireless dosimeters with the simulation of radiation propagation in order to provide a global radiation risk map in the area near the X-ray device. We use a multi-camera RGBD system to obtain a 3D point cloud reconstruction of the room. The positions of the table, C-arm and clinician are then used 1) to simulate the propagation of radiation in a real-world setup and 2) to overlay the resulting 3D risk-map onto the scene in an augmented reality manner. By using real-time wireless dosimeters in our system, we can both calibrate the simulation and validate its accuracy at specific locations in real-time. We demonstrate our system in an operating room equipped with a robotised X-ray imaging device and validate the radiation simulation on several X-ray acquisition setups.
Hellander, Andreas; Lawson, Michael J.; Drawert, Brian; Petzold, Linda
2014-06-01
The efficiency of exact simulation methods for the reaction-diffusion master equation (RDME) is severely limited by the large number of diffusion events if the mesh is fine or if diffusion constants are large. Furthermore, inherent properties of exact kinetic-Monte Carlo simulation methods limit the efficiency of parallel implementations. Several approximate and hybrid methods have appeared that enable more efficient simulation of the RDME. A common feature to most of them is that they rely on splitting the system into its reaction and diffusion parts and updating them sequentially over a discrete timestep. This use of operator splitting enables more efficient simulation but it comes at the price of a temporal discretization error that depends on the size of the timestep. So far, existing methods have not attempted to estimate or control this error in a systematic manner. This makes the solvers hard to use for practitioners since they must guess an appropriate timestep. It also makes the solvers potentially less efficient than if the timesteps were adapted to control the error. Here, we derive estimates of the local error and propose a strategy to adaptively select the timestep when the RDME is simulated via a first order operator splitting. While the strategy is general and applicable to a wide range of approximate and hybrid methods, we exemplify it here by extending a previously published approximate method, the diffusive finite-state projection (DFSP) method, to incorporate temporal adaptivity.
Hellander, Andreas; Lawson, Michael J; Drawert, Brian; Petzold, Linda
2015-01-01
The efficiency of exact simulation methods for the reaction-diffusion master equation (RDME) is severely limited by the large number of diffusion events if the mesh is fine or if diffusion constants are large. Furthermore, inherent properties of exact kinetic-Monte Carlo simulation methods limit the efficiency of parallel implementations. Several approximate and hybrid methods have appeared that enable more efficient simulation of the RDME. A common feature to most of them is that they rely on splitting the system into its reaction and diffusion parts and updating them sequentially over a discrete timestep. This use of operator splitting enables more efficient simulation but it comes at the price of a temporal discretization error that depends on the size of the timestep. So far, existing methods have not attempted to estimate or control this error in a systematic manner. This makes the solvers hard to use for practitioners since they must guess an appropriate timestep. It also makes the solvers potentially less efficient than if the timesteps are adapted to control the error. Here, we derive estimates of the local error and propose a strategy to adaptively select the timestep when the RDME is simulated via a first order operator splitting. While the strategy is general and applicable to a wide range of approximate and hybrid methods, we exemplify it here by extending a previously published approximate method, the Diffusive Finite-State Projection (DFSP) method, to incorporate temporal adaptivity. PMID:26865735
Sepp Neves, Antonio Augusto; Pinardi, Nadia; martins, Flavio
2016-04-01
Every year, 270,000 tonnes of oil are estimated to be spilled in the ocean by vessel operations (e.g. tank washing, leakage of lubricants) and the so called operational spills are typically associated with small volumes and high occurrence rate. Vessel-related accidental spills (e.g. collisions, explosions) seldom occur and usually involve high volumes of oil, accounting for about 100,000 tonnes/year. The occurrence of accidental spills and their impacts have been well documented in the available literature. On the other hand, occurrence rates of operational spills and the effects they have on the marine and coastal environments remain very uncertain due to insufficient sampling effort and methodological limitations. Trying to foresee when and where an oil spill will occur in a certain area, its characteristics and impacts is, at present, impossible. Oil spill risk assessments (OSRAs) have been employed in several parts of the globe in order to deal with such uncertainties and protect the marine environment. In the present work, we computed the oil spill risk applying ensemble oil spill simulations following an ISO-31000 compliant OSRA methodology (Sepp Neves et al. , 2015). The ensemble experiment was carried out for the Algarve coast (southern Portugal) generating a unique data set of 51,200 numerical oil spill simulations covering the main sources of uncertainties (i.e. where and when the spill will happen and oil spill model configuration). From the generated data set, the risk due to accidental and operational spills was mapped for the Algarve municipalities based on the frequency and magnitude (i.e. concentrations) of beaching events and the main sources of risk were identified. The socioeconomic and environmental dimensions of the risk were treated separately. Seasonal changes in the risk index proposed due to the variability of meteo-oceanographic variables (i.e. currents and waves) were also quantified.
S∧4 Reactor: Operating Lifetime and Estimates of Temperature and Burnup Reactivity Coefficients
King, Jeffrey C.; El-Genk, Mohamed S.
2006-01-01
The S∧4 reactor has a sectored, Mo-14%Re solid core for avoidance of single point failures in reactor cooling and Closed Brayton Cycle (CBC) energy conversion. The reactor is loaded with UN fuel, cooled with a He-Xe gas mixture at ~1200 K and operates at steady thermal power of 550 kW. Following a launch abort accident, the axial and radial BeO reflectors easily disassemble upon impact so that the bare reactor is subcriticial when submerged in wet sand or seawater and the core voids are filled with seawater. Spectral Shift Absorber (SSA) additives have been shown to increase the UN fuel enrichment and significantly reduce the total mass of the reactor. This paper investigates the effects of SSA additions on the temperature and burnup reactivity coefficients and the operational lifetime of the S∧4 reactor. SSAs slightly decrease the temperature reactivity feedback coefficient, but significantly increase the operating lifetime by decreasing the burnup reactivity coefficient. With no SSAs, fuel enrichment is only 58.5 wt% and the estimated operating lifetime is the shortest (7.6 years) with the highest temperature and burnup reactivity feedback coefficients (-0.2709 ¢/K and -1.3470 $/atom%). With europium-151 and gadolinium-155 additions, the enrichment (91.5 and 94 wt%) and operating lifetime (9.9 and 9.8 years) of the S∧4 reactor are the highest while the temperature and burnup reactivity coefficients (-0.2382 and -0.2447 ¢/K -0.9073 and 0.8502 $/atom%) are the lowest.
The TileCal Online Energy Estimation for the Next LHC Operation Period
Peralva, B S; The ATLAS collaboration
2014-01-01
The ATLAS Tile Calorimeter (TileCal) is the detector used in the reconstruction of hadrons, jets, muons and missing transverse energy from the proton-proton collisions at the Large Hadron Collider (LHC). It covers the central part of the ATLAS detector (|η|<1.6). The energy deposited by the particles is read out by approximately 5,000 cells, with double readout channels. The signal provided by the readout electronics for each channel is digitized at 40 MHz and its amplitude is estimated by an optimal filtering algorithm, which expects a single signal with a well-defined shape. However, the LHC luminosity is expected to increase leading to signal pile-up that deforms the signal of interest. Due to limited resources, the current DSP-based hardware setup does not allow the implementation of sophisticated energy estimation methods that deal with the pile-up. Therefore, the technique to be employed for online energy estimation in TileCal for next LHC operation period must be based on fast filters such as the M...
The TileCal Online Energy Estimation for the Next LHC Operation Period
Peralva, B S; The ATLAS collaboration; Cerqueira, A S; Seixas, J M
2014-01-01
This work presents a study on the TileCal online energy estimation for the next LHC operation period (Run2). Due to hardware limitation, the algorithm that performs the online energy estimation must remain based on the linear and fast Optimal Filter (OF) technique, which envisages the use of the background covariance matrix in its design. During Run1, TileCal made use of an identity matrix to describe and the background covariance matrix, which showed to be a reasonable approximation for the low luminosity scenario. Under such conditions, the background for most of its cells comprised mainly electronic noise which can be approximated as a uncorrelated Gaussian process. However, as the pile-up introduces a non-Gaussian component to the background, the OF method presents larger variance and it becomes biased. The use of the background covariance matrix in the design of the OF weights is expected to improve the energy estimation performance. The results for the scenario considered show that for high occupancy ce...
Estimates of emergency operating capacity in U.S. manufacturing industries: 1994--2005
Energy Technology Data Exchange (ETDEWEB)
Belzer, D.B.
1997-02-01
To develop integrated policies for mobilization preparedness, planners require estimates and projections of available productive capacity during national emergency conditions. This report develops projections of national emergency operating capacity (EOC) for 458 US manufacturing industries at the 4-digit Standard Industrial Classification (SIC) level. These measures are intended for use in planning models that are designed to predict the demands for detailed industry sectors that would occur under conditions such as a military mobilization or a major national disaster. This report is part of an ongoing series of studies prepared by the Pacific Northwest National Laboratory to support mobilization planning studies of the Federal Emergency Planning Agency/US Department of Defense (FEMA/DOD). Earlier sets of EOC estimates were developed in 1985 and 1991. This study presents estimates of EOC through 2005. As in the 1991 study, projections of capacity were based upon extrapolations of equipment capital stocks. The methodology uses time series regression models based on industry data to obtain a response function of industry capital stock to levels of industrial output. The distributed lag coefficients of these response function are then used with projected outputs to extrapolate the 1994 level of EOC. Projections of industrial outputs were taken from the intermediate-term forecast of the US economy prepared by INFORUM (Interindustry Forecasting Model, University of Maryland) in the spring of 1996.
FARE device operational characteristics of remote controlled fuelling machine at Wolsong NPP
Energy Technology Data Exchange (ETDEWEB)
Namgung, I. [Korea Power Engineering Co., Taejon (Korea, Republic of); Kim, Y. B.; Lee, S. K. [Korea Electric Power Research Institute, Taejon (Korea, Republic of)
2002-10-01
There are 4 CANDU6 type reactors operating at Wolsong site. For fuelling operation of certain fuel channels (with flow less than 21.5 kg/s) a FARE (flow Assist Ram Extension) device is used. During the refuelling operation, two remote controlled F/Ms (Fuelling Machines) are attached to a designated fuel channel and carry out refuelling job. The upstream F/M inserts new fuel bundles into the fuel channel while the downstream F/M discharges spent fuel bundles. In order to assist fuelling operation of channels that has lower coolant flow rate, the FARE device is used instead of F/M C-ram to push the fuel bundle string. The FARE device is essentially a flow restricting element that produces enough drag force to push the fuel bundle string toward downstream F/M. Channels that require the use of FARE device for refuelling are located along the outside perimeter of reactor. This paper presents the FARE device design feature, steady state hydraulic and operational characteristics and behavior of the device when coupled with fuel bundle string during fuelling operation. The study showed that the steady state performance of Fare device meets the design objective that was confirmed by downstream F/M C-ram force to be positive.
Operational evapotranspiration estimates from SEVIRI in support of sustainable water management
Petropoulos, George P.; Ireland, Gareth; Lamine, Salim; Griffiths, Hywel M.; Ghilain, Nicolas; Anagnostopoulos, Vasileios; North, Matthew R.; Srivastava, Prashant K.; Georgopoulou, Hro
2016-07-01
This study aimed at evaluating the accuracy of the evapotranspiration (ET) operational estimates from the Meteosat Second Generation (MSG) Spinning Enhanced Visible Infra-Red Imager (SEVIRI) at a range of selected ecosystems in Europe. For this purpose in-situ eddy covariance measurements were used, acquired from 7 selected experimental sites belonging to the CarboEurope ground observational network over 2 full years of observations (2010-2011). Appraisal of ET accuracy was also investigated with respect to land cover, season and each site(s) degree of heterogeneity, the latter being expressed by the fractional vegetation cover (FVC) operational product of SEVIRI. Results indicated a close agreement between the operational product's ET estimates and the tower based in-situ ET measurements for all days of comparison, showing a satisfactory correlation (r of 0.709) with accuracies often comparable to previous analogous studies. For all land cover types, the grassland and cropland sites exhibited the closest agreement (r from 0.705 to 0.759). In terms of seasons the strongest correlations were observed during the summer and autumn (r of 0.714 & 0.685 respectively), and with FVC the highest correlation of 0.735 was observed for the class FVC 0.75-1 when compared against the observed values for the complete monitoring period. Our findings support the potential value of the SEVIRI ET product for regional to mesoscale studies and corroborate its credibility for usage in many practical applications. The latter is of particular importance for water limiting environments, such as those found in the Mediterranean basin, as accurate information on ET rates can provide tremendous support in sustainable water resource management as well as policy and decision making in those areas.
Flow and containment characteristics of an air-curtain fume hood operated at high temperatures.
Chen, Jia-Kun; Huang, Rong Fung; Hsin, Pei-Yi; Hsu, Ching Min; Chen, Chun-Wann
2012-01-01
The flow and leakage characteristics of the air-curtain fume hood under high temperature operation (between 100°C and 250°C) were studied. Laser-assisted flow visualization technique was used to reveal the hot plume movements in the cabinet and the critical conditions for the hood-top leakage. The sulfur hexafluoride tracer-gas concentration test method was employed to examine the containment spillages from the sash opening and the hood top. It was found that the primary parameters dominating the behavior of the flow field and hood performance are the sash height and the suction velocity as an air-curtain hood is operated at high temperatures. At large sash height and low suction velocity, the air curtain broke down and accompanied with three-dimensional flow in the cabinet. Since the suction velocity was low and the sash opening was large, the makeup air drawn down from the hood top became insufficient to counter act the rising hot plume. Under this situation, containment leakage from the sash opening and the hood top was observed. At small sash opening and high suction velocity, the air curtain presented robust characteristics and the makeup air flow from the hood top was sufficiently large. Therefore the containment leakages from the sash opening and the hood top were not observed. According to the results of experiments, quantitative operation sash height and suction velocity corresponding to the operation temperatures were suggested.
Operational Definitions of Sexual Orientation and Estimates of Adolescent Health Risk Behaviors.
Matthews, Derrick D; Blosnich, John R; Farmer, Grant W; Adams, Brian J
2014-03-01
Increasing attention to the health of lesbian, gay, and bisexual (LGB) populations comes with requisite circumspection about measuring sexual orientation in surveys. However, operationalizing these variables also requires considerable thought. This research sought to document the consequences of different operational definitions of sexual orientation by examining variation in health risk behaviors. Using Massachusetts Youth Risk Behavior Survey data, we examined how operational definitions of sexual behavior and sexual identity influenced differences among three health behaviors known to disparately affect LGB populations: smoking, suicide risk, and methamphetamine use. Sexual behavior and sexual identity were also examined together to explore if they captured unique sources of variability in behavior. Estimates of health disparities changed as a result of using either sexual behavior or sexual identity. Youth who reported their sexual identity as "not sure" also had increased odds of health risk behavior. Disaggregating bisexual identity and behavior from same-sex identity and behavior frequently resulted in the attenuation or elimination of health disparities that would have otherwise been attributable to exclusively same-sex sexual minorities. Finally, sexual behavior and sexual identity explained unique and significant sources of variability in all three health behaviors. Researchers using different operational definitions of sexual orientation could draw different conclusions, even when analyzing the same data, depending upon how they chose to represent sexual orientation in analyses. We discuss implications that these manipulations have on data interpretation and provide specific recommendations for best-practices when analyzing sexual orientation data collected from adolescent populations.
Can a snow structure model estimate snow characteristics relevant to reindeer husbandry?
Directory of Open Access Journals (Sweden)
Sirpa Rasmus
2014-02-01
Full Text Available Snow affects foraging conditions of reindeer e.g. by increasing the energy expenditures for moving and digging work or, in contrast, by making access of arboreal lichen easier. Still the studies concentrating on the role of the snow pack structure on reindeer population dynamics and reindeer management are few. We aim to find out which of the snow characteristics are relevant for reindeer in the northern boreal zone according to the experiences of reindeer herders and is this relevance seen also in reproduction rate of reindeer in this area. We also aim to validate the ability of the snow model SNOWPACK to reliably estimate the relevant snow structure characteristics. We combined meteorological observations, snow structure simulations by the model SNOWPACK and annual reports by reindeer herders during winters 1972-2010 in the Muonio reindeer herding district, northern Finland. Deep snow cover and late snow melt were the most common unfavorable conditions reported. Problematic conditions related to snow structure were icy snow and ground ice or unfrozen ground below the snow, leading to mold growth on ground vegetation. Calf production percentage was negatively correlated to the measured annual snow depth and length of the snow cover time and to the simulated snow density. Winters with icy snow could be distinguished in three out of four reported cases by SNOWPACK simulations and we could detect reliably winters with conditions favorable for mold growth. Both snow amount and also quality affects the reindeer herding and reindeer reproduction rate in northern Finland. Model SNOWPACK can relatively reliably estimate the relevant structural properties of snow. Use of snow structure models could give valuable information about grazing conditions, especially when estimating the possible effects of warming winters on reindeer populations and reindeer husbandry. Similar effects will be experienced also by other arctic and boreal species.
Institute of Scientific and Technical Information of China (English)
Amin Manouchehrian; Mostafa Sharifzadeh; Rasoul Hamidzadeh Moghadam
2012-01-01
Before any rock engineering project,mechanical parameters of rocks such as uniaxial compressive strength and young modulus of intact rock get measured using laboratory or in-situ tests,but in some situations preparing the required specimens is impossible.By this time,several models have been established to evaluate UCS and E from rock substantial properties.Artificial neural networks are powerful tools which are employed to establish predictive models and results have shown the priority of this technique compared to classic statistical techniques.In this paper,ANN and multivariate statistical models considering rock textural characteristics have been established to estimate UCS of rock and to validate the responses of the established models,they were compared with laboratory results.For this purpose a data set for 44 samples of sandstone was prepared and for each sample some textural characteristics such as void,mineral content and grain size as well as UCS were determined.To select the best predictors as inputs of the UCS models,this data set was subjected to statistical analyses comprising basic descriptive statistics,bivariate correlation,curve fitting and principal component analyses.Results of such analyses have shown that void,ferroan calcitic cement,argillaceous cement and mica percentage have the most effect on USC Two predictive models for UCS were developed using these variables by ANN and linear multivariate regression.Results have shown that by using simple textural characteristics such as mineral content,cement type and void,strength of studied sandstone can be estimated with acceptable accuracy.ANN and multivariate statistical UCS models,revealed responses with 0.87 and 0.76 regressions,respectively which proves higher potential of ANN model for predicting UCS compared to classic statistical models.
Wanigaratne, S; Holowaty, E; Jiang, H; Norwood, T A; Pietrusiak, M A; Brown, P
2013-09-01
Evidence suggests that current levels of tritium emissions from CANDU reactors in Canada are not related to adverse health effects. However, these studies lack tritium-specific dose data and have small numbers of cases. The purpose of our study was to determine whether tritium emitted from a nuclear-generating station during routine operation is associated with risk of cancer in Pickering, Ontario. A retrospective cohort was formed through linkage of Pickering and north Oshawa residents (1985) to incident cancer cases (1985-2005). We examined all sites combined, leukemia, lung, thyroid and childhood cancers (6-19 years) for males and females as well as female breast cancer. Tritium estimates were based on an atmospheric dispersion model, incorporating characteristics of annual tritium emissions and meteorology. Tritium concentration estimates were assigned to each cohort member based on exact location of residence. Person-years analysis was used to determine whether observed cancer cases were higher than expected. Cox proportional hazards regression was used to determine whether tritium was associated with radiation-sensitive cancers in Pickering. Person-years analysis showed female childhood cancer cases to be significantly higher than expected (standardized incidence ratio [SIR] = 1.99, 95% confidence interval [CI]: 1.08-3.38). The issue of multiple comparisons is the most likely explanation for this finding. Cox models revealed that female lung cancer was significantly higher in Pickering versus north Oshawa (HR = 2.34, 95% CI: 1.23-4.46) and that tritium was not associated with increased risk. The improved methodology used in this study adds to our understanding of cancer risks associated with low-dose tritium exposure. Tritium estimates were not associated with increased risk of radiationsensitive cancers in Pickering.
Eun, Yeonju; Jeon, Daekeun; Lee, Hanbong; Zhu, Zhifan; Jung, Yoon C.; Jeong, Myeongsook; Kim, Hyounkyong; Oh, Eunmi; Hong, Sungkwon; Lee, Junwon
2016-01-01
integrated into NASA's Airspace Technology Demonstration-2 (ATD-2) project for technology demonstration of Integrated Arrival-Departure-Surface (IADS) operations at CLT. This study is a part of the international research collaboration between KAIA (Korea Agency for Infrastructure Technology Advancement), KARI (Korea Aerospace Research Institute) and NASA, which is being conducted to validate the effectiveness of SARDA concept as a controller decision support tool for departure and surface management of ICN. This paper presents the preliminary results of the collaboration effort. It includes investigation of the operational environment of ICN, data analysis for identification of the operational characteristics of the airport, construction and verification of airport simulation model using Surface Operations Simulator and Scheduler (SOSS), NASA's fast-time simulation tool.
Beam Size Estimation from Luminosity Scans at the LHC During 2015 Proton Physics Operation
Hostettler, Michael
2016-01-01
As a complementary method for measuring the beam size for high-intensity beams at 6.5 TeV flat-top energy, beam separation scans were done regularly at the CERN Large Hadron Collider (LHC) during 2015 proton physics operation. The luminosities measured by the CMS experiment during the scans were used to derive the convoluted beam size and orbit offset bunch-by-bunch. This contribution will elaborate on the method used to derive plane-by-plane, bunch-by-bunch emittances from the scan data, including uncertainties and corrections. The measurements are then compared to beam size estimations from absolute luminosity, synchrotron light telescopes, and wire scanners. In particular, the evolution of the emittance over the course of several hours in collisions is studied and bunch-by-bunch differences are highlighted.
Schauder estimates for parabolic nondivergence operators of Hörmander type
Bramanti, Marco; Brandolini, Luca
Let X,X,…,X be a system of real smooth vector fields satisfying Hörmander's rank condition in a bounded domain Ω of R. Let A={a(t,x)}i,j=1q be a symmetric, uniformly positive definite matrix of real functions defined in a domain U⊂R×Ω. For operators of kind H=∂-∑i,j=1qa(t,x)XX-∑i=1qb(t,x)X-c(t,x) we prove local a-priori estimates of Schauder-type, in the natural (parabolic) C(U) spaces defined by the vector fields X and the distance induced by them. Namely, for a, b, c∈C(U) and U⋐U, we prove ‖u‖⩽c{‖Hu‖+‖u‖}.
Energy Technology Data Exchange (ETDEWEB)
Ikeda, Mitsuru; Mizoguchi, Riichirou [Inst. of Scientific and Industrial Research, Osaka Univ., Ibaraki (Japan); Yoshikawa, Shinji; Ozawa, Kenji
1997-03-01
This report describes a technical survey of acquisition method of an operator`s understanding for functions and structures of his target nuclear plant. This method is to play a key role in the information processing framework to support on-training operators in forming their knowledge of the nuclear plants. This kind of technical framework is aiming at enhancing human operator`s ability to cope with anomaly plant situations which are difficult to expect from preceding experiences or engineering surveillance. In these cases, cause identifications and responding operation selections are desired to made not only empirically but also based on thoughts about possible phenomena to take place within the nuclear plant. This report focuses on a particular element technique, defined as `explanation-based knowledge acquisition`, as the candidate technique to potentially be extended to meet the requirement written above, and discusses about applicability to the learning support system and about necessary improvements, to identify future technical developments. (author)
Long-term operating characteristics of Japan’s first in-grid HTS power cable
Energy Technology Data Exchange (ETDEWEB)
Nakano, Tetsutaro, E-mail: nakano.tetsutaro@tepco.co.jp [Tokyo Electric Power Company, 4-1 Egasaki-cho, Tsurumi-ku, Yokohama 230-8510 (Japan); Maruyama, Osamu; Honjo, Shoichi [Tokyo Electric Power Company, 4-1 Egasaki-cho, Tsurumi-ku, Yokohama 230-8510 (Japan); Watanabe, Michihiko; Masuda, Takato; Hirose, Masayuki [Sumitomo Electric Industries, Ltd., 1-1-3 Shimaya, Konohana-ku, Osaka 554-004 (Japan); Shimoda, Masahiro; Nakamura, Naoko; Yaguchi, Hiroharu; Machida, Akito [Mayekawa Mfg. Co., Ltd., 2000 Tatsuzawa, Moriya-shi, Ibaraki 302-0018 (Japan)
2015-11-15
Highlights: • The in-grid operation had continued for more than one year without serious troubles. • The LN{sub 2} temperature and pressure were controlled stably within the preset range. • No degradation of I{sub c} occurred against the designed value after in-grid operation. • The degradation rate of cooling power differed among the refrigerators. - Abstract: Tokyo Electric Power Company, Sumitomo Electric Industries, Ltd and Mayekawa Mfg. Co., Ltd have jointly conducted the first in-grid demonstration test of a high-temperature superconducting (HTS) cable in Japan, from FY2007 to FY2013. The objective of this project is to evaluate the reliability, stability and other characteristics of the system. The cable structure used in this project is the type of three-in-one cable. As a coolant, sub-cooled liquid nitrogen flows through the gap between the corrugated cryostat and the three cable cores. This structure can realize compactness and reduce heat invasion compared with three single-core HTS cables housed in separate cryostats. The cooling system consists of six refrigerators, two circulation pumps and a reservoir tank. Each refrigerator has a cooling power of 1.0 kW at 77 K, 0.8 kW at 67 K. The number of operating refrigerators is controlled so that the coolant temperature at the cable inlet is kept to preset value. The HTS cable was connected to the live electricity grid from October 29, 2012 to December 25, 2013. In-grid operation continued for more than one year without any accidental interruption of operation or other operating issues. During this time, we studied the operating performance of the HTS cable in dependence on the sub-cooled LN{sub 2} temperature.
Directory of Open Access Journals (Sweden)
Tatyana P. Levchenko
2011-01-01
Full Text Available The article considers methods of estimation of qualitative and quantitative characteristics interrelation, having impact on amount of tourists in hospitality industry, offers the latest technologies of the given indicators calculation.
Tian, Zhang; Yanfeng, Gong
2017-05-01
In order to solve the contradiction between demand and distribution range of primary energy resource, Ultra High Voltage (UHV) power grids should be developed rapidly to meet development of energy bases and accessing of large-scale renewable energy. This paper reviewed the latest research processes of AC/DC transmission technologies, summarized the characteristics of AC/DC power grids, concluded that China’s power grids certainly enter a new period of large -scale hybrid UHV AC/DC power grids and characteristics of “strong DC and weak AC” becomes increasingly pro minent; possible problems in operation of AC/DC power grids was discussed, and interaction or effect between AC/DC power grids was made an intensive study of; according to above problems in operation of power grids, preliminary scheme is summarized as fo llows: strengthening backbone structures, enhancing AC/DC transmission technologies, promoting protection measures of clean energ y accessing grids, and taking actions to solve stability problems of voltage and frequency etc. It’s valuable for making hybrid UHV AC/DC power grids adapt to operating mode of large power grids, thus guaranteeing security and stability of power system.
Zietzschmann, Frederik; Altmann, Johannes; Ruhl, Aki Sebastian; Dünnbier, Uwe; Dommisch, Ingvild; Sperlich, Alexander; Meinel, Felix; Jekel, Martin
2014-06-01
Eight commercially available powdered activated carbons (PAC) were examined regarding organic micro-pollutant (OMP) removal efficiencies in wastewater treatment plant (WWTP) effluent. PAC characteristic numbers such as B.E.T. surface, iodine number and nitrobenzene number were checked for their potential to predict the OMP removal of the PAC products. Furthermore, the PAC-induced removal of UV254 nm absorption (UVA254) in WWTP effluent was determined and also correlated with OMP removal. None of the PAC characteristic numbers can satisfactorily describe OMP removal and accordingly, these characteristics have little informative value on the reduction of OMP concentrations in WWTP effluent. In contrast, UVA254 removal and OMP removal correlate well for carbamazepine, diclofenac, and several iodinated x-ray contrast media. Also, UVA254 removal can roughly describe the average OMP removal of all measured OMP, and can accordingly predict PAC performance in OMP removal. We therefore suggest UVA254 as a handy indicator for the approximation of OMP removal in practical applications where direct OMP concentration quantification is not always available. In continuous operation of large-scale plants, this approach allows for the efficient adjustment of PAC dosing to UVA254, in order to ensure reliable OMP removal whilst minimizing PAC consumption. Copyright © 2014 Elsevier Ltd. All rights reserved.
Sampling characteristics and calibration of snorkel counts to estimate stream fish populations
Weaver, D.; Kwak, Thomas J.; Pollock, Kenneth
2014-01-01
Snorkeling is a versatile technique for estimating lotic fish population characteristics; however, few investigators have evaluated its accuracy at population or assemblage levels. We evaluated the accuracy of snorkeling using prepositioned areal electrofishing (PAE) for estimating fish populations in a medium-sized Appalachian Mountain river during fall 2008 and summer 2009. Strip-transect snorkel counts were calibrated with PAE counts in identical locations among macrohabitats, fish species or taxa, and seasons. Mean snorkeling efficiency (i.e., the proportion of individuals counted from the true population) among all taxa and seasons was 14.7% (SE, 2.5%), and the highest efficiencies were for River Chub Nocomis micropogon at 21.1% (SE, 5.9%), Central Stoneroller Campostoma anomalum at 20.3% (SE, 9.6%), and darters (Percidae) at 17.1% (SE, 3.7%), whereas efficiencies were lower for shiners (Notropis spp., Cyprinella spp., Luxilus spp.) at 8.2% (SE, 2.2%) and suckers (Catostomidae) at 6.6% (SE, 3.2%). Macrohabitat type, fish taxon, or sampling season did not significantly explain variance in snorkeling efficiency. Mean snorkeling detection probability (i.e., probability of detecting at least one individual of a taxon) among fish taxa and seasons was 58.4% (SE, 6.1%). We applied the efficiencies from our calibration study to adjust snorkel counts from an intensive snorkeling survey conducted in a nearby reach. Total fish density estimates from strip-transect counts adjusted for snorkeling efficiency were 7,288 fish/ha (SE, 1,564) during summer and 15,805 fish/ha (SE, 4,947) during fall. Precision of fish density estimates is influenced by variation in snorkeling efficiency and sample size and may be increased with additional sampling effort. These results demonstrate the sampling properties and utility of snorkeling to characterize lotic fish assemblages with acceptable efficiency and detection probability, less effort, and no mortality, compared with traditional
Waste Estimates for a Future Recycling Plant in the US Based Upon AREVA Operating Experience - 13206
Energy Technology Data Exchange (ETDEWEB)
Foare, Genevieve; Meze, Florian [AREVA E and P, SGN - 1, rue des Herons, 78182 Montigny-le-Bretonneux (France); Bader, Sven; McGee, Don; Murray, Paul [AREVA Federal Services LLC, 7207 IBM Drive, Mail Code CLT- 1D, Charlotte NC 28262 (United States); Prud' homme, Pascal [AREVA NC SA - 1, place Jean Millier, 92084 Paris La Defense CEDEX (France)
2013-07-01
Estimates of process and secondary wastes produced by a recycling plant built in the U.S., which is composed of a used nuclear fuel (UNF) reprocessing facility and a mixed oxide (MOX) fuel fabrication facility, are performed as part of a U.S. Department of Energy (DOE) sponsored study [1]. In this study, a set of common inputs, assumptions, and constraints were identified to allow for comparison of these wastes between different industrial teams. AREVA produced a model of a reprocessing facility, an associated fuel fabrication facility, and waste treatment facilities to develop the results for this study. These facilities were divided into a number of discrete functional areas for which inlet and outlet flow streams were clearly identified to allow for an accurate determination of the radionuclide balance throughout the facility and the waste streams. AREVA relied primarily on its decades of experience and feedback from its La Hague (reprocessing) and MELOX (MOX fuel fabrication) commercial operating facilities in France to support this assessment. However, to perform these estimates for a U.S. facility with different regulatory requirements and to take advantage of some technological advancements, such as in the potential treatment of off-gases, some deviations from this experience were necessary. A summary of AREVA's approach and results for the recycling of 800 metric tonnes of initial heavy metal (MTIHM) of LWR UNF per year into MOX fuel under the assumptions and constraints identified for this DOE study are presented. (authors)
An Operational System for Estimating Road Traffic Information from Aerial Images
Directory of Open Access Journals (Sweden)
Jens Leitloff
2014-11-01
Full Text Available Given that ground stationary infrastructures for traffic monitoring are barely able to handle everyday traffic volumes, there is a risk that they could fail altogether in situations arising from mass events or disasters. In this work, we present an alternative approach for traffic monitoring during disaster and mass events, which is based on an airborne optical sensor system. With this system, optical image sequences are automatically examined on board an aircraft to estimate road traffic information, such as vehicle positions, velocities and driving directions. The traffic information, estimated in real time on board, is immediately downlinked to a ground station. The airborne sensor system consists of a three-head camera system, a real-time-capable GPS/INS unit, five industrial PCs and a downlink unit. The processing chain for automatic extraction of traffic information contains modules for the synchronization of image and navigation data streams, orthorectification and vehicle detection and tracking modules. The vehicle detector is based on a combination of AdaBoost and support vector machine classifiers. Vehicle tracking relies on shape-based matching operators. The processing chain is evaluated on a large number of image sequences recorded during several campaigns, and the data quality is compared to that obtained from induction loops. In summary, we can conclude that the achieved overall quality of the traffic data extracted by the airborne system is in the range of 68% and 81%. Thus, it is comparable to data obtained from stationary ground sensor networks.
Smith, S J; Perry, R I; Fanning, L P
1991-01-01
The Canadian Department of Fisheries and Oceans conducts annual bottom trawl surveys to monitor changes in the abundance of the major commercially important groundfish populations. Some of these surveys have been in operation for almost 20 yr. The estimates from these surveys often indicate rapid changes in abundance over time beyond that expected from the population dynamics of the fish. Much of this interannual change has been interpreted as variation, the magnitude of which has often made it difficult to measure anything but the most severe effects of fishing, pollution or any other intervention on the population. Recent studies have shown that some of this variation may be attributed to changes in catchability of fish due to the effects of environmental variables on fish distribution. Annual changes in abundance as estimated from such field surveys may be confounded by changes in catchability due to annual changes in environmental conditions. In this study, trawl catches of age 4 Atlantic cod (Gadus morhua) from surveys conducted during March 1979-1988 were compared with concurrent measurements of bottom salinity, temperature and depth. Large catches of age 4 cod are more likely to occur in water characterized as the intermediate cold layer defined by salinities of 32-33.5 and temperatures<5°C. This relationship also appears to be modified by depth. We further show that internnual changes in the estimated abundance from the surveys were, in a number of cases, coincident with changes in the proportion of the bottom water composed of the intermediate cold water layer. The implications that these patterns may have on interpreting trends in the estimates of abundance from trawl surveys are discussed.
Skafte, Anders; Aenlle, Manuel L.; Brincker, Rune
2016-02-01
Measurement systems are being installed in more and more civil structures with the purpose of monitoring the general dynamic behavior of the structure. The instrumentation is typically done with accelerometers, where experimental frequencies and mode shapes can be identified using modal analysis and used in health monitoring algorithms. But the use of accelerometers is not suitable for all structures. Structures like wind turbine blades and wings on airplanes can be exposed to lightning, which can cause the measurement systems to fail. Structures like these are often equipped with fiber sensors measuring the in-plane deformation. This paper proposes a method in which the displacement mode shapes and responses can be predicted using only strain measurements. The method relies on the newly discovered principle of local correspondence, which states that each experimental mode can be expressed as a unique subset of finite element modes. In this paper the technique is further developed to predict the mode shapes in different states of the structure. Once an estimate of the modes is found, responses can be predicted using the superposition of the modal coordinates weighted by the mode shapes. The method is validated with experimental tests on a scaled model of a two-span bridge installed with strain gauges. Random load was applied to simulate a civil structure under operating condition, and strain mode shapes were identified using operational modal analysis.
Directory of Open Access Journals (Sweden)
Ashis De
2014-01-01
Full Text Available In this paper a detailed comparison between the estimation results of unknown inputs of a linear time invariant system using projection operator approach and using the method of generalized matrix inverse have been discussed. The full order observer constructed using projection operator approach has been extended and implemented for this purpose.
Energy Technology Data Exchange (ETDEWEB)
Jang, C. M.; Kim, D. W. [Korea Institute of Construction Technology, Goyang (Korea, Republic of); Lee, S. Y. [ANST, Seoul (Korea, Republic of)
2008-10-15
A simulator for a refuse collecting system is designed to investigate the performance characteristics of a turbo blower operating at different rotational frequencies. The simulator consists of an air intake, a waste chute, circular duct, waste collector and turbo blower. Experimental measurements and numerical simulation with three-dimensional Navier- Stokes equations have been performed to analyze the performance of the turbo blower. Throughout numerical simulation of the simulator, it is found that the input energy of the blower can be reduced by controlling the rotational frequency of impeller while the efficiency of the blower keeps constant. The required outlet pressure and flow rate of the blower can be also adjusted along the system resistance of the refuse collecting system. Detailed flow characteristics inside the blower are analyzed for different rotational frequencies
[Comparative characteristic of methods for operative treatment of patients suffering varicocele].
Boĭko, M I; Pasiechnikov, S P; Boĭko, O M
2014-04-01
Efficacy and security of treatment of varicocele constitute a complex issues in urology, necessitating the additional investigations conduction. The results of surgical treatment of 280 patients, suffering left-sided varicocele and operated using three different methods--retroperitoneal varicocelectomy, laparoscopic varicocelectomy and subinguinal microsurgical varicocelectomy (SMV)--were analyzed. The advantages and faults of these methods were estimated, basing on the recurrence rate, complications by hidrocele occurrence and changes in the patients quality of life. SMV was determined as most effective and secure method of varicocele correction. The data obtained may be useful for choice of tactics for the disease treatment.
Energy Technology Data Exchange (ETDEWEB)
Vilkov, N.Ya.; Krjukov, Yu.V.; Blinov, S.V. [Alexandrov Research Inst. of Technology (Russian Federation); Fedoseev, M.V. [VNIIAES (Russian Federation)
2002-07-01
Based on actual data obtained from operative chemical monitoring in operating NPPs, the authors show the use of some probability diagnosis methods in practical applications such as identification of anomalies of the water chemistry condition, specifically, in the following: detecting violation of control limits a priori determined for the water chemistry parameters, using the control card method; construction of detectors for identifying probably (statistically) significant stepwise changes in the current arithmetical mean of the water chemistry parametric values; identifying successive changes in the behavior of robust estimators of the monitored parameters values; construction of robust linear regression prognostic models for dynamic changes in the monitored parameters values; correlation analysis of time series formed from the measured data on the water chemistry connected parameters (which are lumped (concentrated at one control point) and/or distributed along the coolant path). (author)
Dugger, A. L.; Gochis, D. J.; Yu, W.; McCreight, J. L.; Barlage, M. J.
2015-12-01
The "next generation" of hydrologic prediction systems - targeting unified, process-based, real-time prediction of the total water cycle - bring with them an increased need for real-time land surface characterization. Climatologically-derived estimates may perform well under stationary conditions, however disturbance can significantly alter hydrologic behavior and may be poorly represented by mean historical conditions. Fortunately, remote sensing and on-the-ground observation networks are collecting snapshots of these land characteristics over an increasing fraction of the globe. Given the computing constraints of operating a large-domain, real-time prediction system, to take advantage of these data streams we need a way to prioritize which landscape characteristics are most important to hydrologic prediction post-disturbance. To address this need, we setup a model experiment over the contiguous US using the community WRF-Hydro system with the NoahMP land surface model to assess the value of incorporating various aspects of disturbed landscapes into a real-time streamflow prediction model. WRF-Hydro will serve as the initial operational model for the US National Weather Service's new national water prediction effort, so use of WRF-Hydro allows us to leverage both an existing CONUS-scale model implementation and a short research-to-operations path. We first identify USGS GAGES-II basins that experienced more than 25% forest loss between 2000 and 2013. Based on basin disturbance type, geophysical setting, and climate regime, we formulate a conceptual model of which "disturbed" landscape characteristics we expect to dominate streamflow response. We test our conceptual model using WRF-Hydro by modeling a baseline (no disturbance) case, and then bringing in empirically-derived model state shifts representing key disturbance characteristics (e.g., leaf area index, rooting depth, overland roughness, surface detention). For each state update and each basin, we quantify
Musielak-Orlicz-Hardy Spaces Associated with Operators Satisfying Reinforced Off-Diagonal Estimates
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Bui The Anh
2013-02-01
Full Text Available Let X be a metric space with doubling measure and L a one-to-one operator of type ω having a bounded H∞ -functional calculus in L2(X satisfying the reinforced (pL; qL off-diagonal estimates on balls, where pL ∊ [1; 2 and qL ∊ (2;∞]. Let φ : X × [0;∞ → [0;∞ be a function such that φ (x;· is an Orlicz function, φ(·;t ∊ A∞(X (the class of uniformly Muckenhoupt weights, its uniformly critical upper type index l(φ ∊ (0;1] and φ(·; t satisfies the uniformly reverse Hölder inequality of order (qL/l(φ′, where (qL/l(φ′ denotes the conjugate exponent of qL/l(φ. In this paper, the authors introduce a Musielak-Orlicz-Hardy space Hφ;L(X, via the Lusin-area function associated with L, and establish its molecular characterization. In particular, when L is nonnegative self-adjoint and satisfies the Davies-Gaffney estimates, the atomic characterization of Hφ,L(X is also obtained. Furthermore, a sufficient condition for the equivalence between Hφ,L(ℝn and the classical Musielak-Orlicz-Hardy space Hv(ℝn is given. Moreover, for the Musielak-Orlicz-Hardy space Hφ,L(ℝn associated with the second order elliptic operator in divergence form on ℝn or the Schrödinger operator L := −Δ + V with 0 ≤ V ∊ L1loc(ℝn, the authors further obtain its several equivalent characterizations in terms of various non-tangential and radial maximal functions; finally, the authors show that the Riesz transform ∇L−1/2 is bounded from Hφ,L(ℝn to the Musielak-Orlicz space Lφ(ℝn when i(φ ∊ (0; 1], from Hφ,L(ℝn to Hφ(ℝn when i(φ ∊ (; 1], and from Hφ,L(ℝn to the weak Musielak-Orlicz-Hardy space WHφ(ℝn when i(φ=is attainable and φ(·; t ∊ A1(X, where i(φ denotes the uniformly critical lower type index of φ
Operation characteristics of AMS-02 loop heat pipe with bypass valve
Wang, N H; Xin, G M; Song, J W; Cui, Z; Burger, J; Du, W J; Luo, F; Cheng, L
2011-01-01
Loop heat pipes (LHPs) were designed for the alpha magnetic spectrometer (AMS-02) to dissipate heat from the cryocoolers. A bypass valve is applied to the LHP to keep the cryocooler temperature above its limit (-20A degrees C) in cold environment. Extensive experiments were performed on operation characteristics of LHPs with the bypass valve for AMS-02 during thermal vacuum and thermal balance (TVTB) test. We found that the bypass valve can start up successfully in cold environment. With the bypass valve, the evaporator temperature is stable and can meet the requirement of the cryocooler. We analyzed three operating modes of the bypass valve. Set point temperature and regulation temperature shifts were observed and their relations with the bypass valve temperature were given.
Miyagi, Katsunori; Oe, Etsuo; Yamagata, Naoki; Miyahara, Hideyuki
A sudden capacity increase in demand during the summer peak, or in contingencies such as malfunctioning transformers, may cause overload for normal transformers. In this paper, on the basis of examples of overloaded transformer operation in distributing substations, thermal aging testing in oil was carried out under various overload patterns, such as short time overload and long time overload, but with the winding insulation paper's life loss kept constant. From the results, various characteristics such as mean degree of polymerization and productions of furfural and (CO2+CO), and their effects on the life loss of the insulation paper were obtained.
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
The organic static induction transistors (OSITs) are fabricated by the method of evaporating and plating in a vacuum with copper phthalocyanine (CuPc) dye, and has a five layered structure of Au/CuPc/AL/CuPc/Au. The experiment reveals that OSITs have obtained a low driving voltage, high current density and high switch speed such as IDs = 1.2 × 10-6A/mm2 , and the degree of 1 000 Hz. The OSITs have excellent operation characteristics of typical static induction transistors.
Batzias, D. F.; Pollalis, Y. A.
2007-12-01
This work deals with the determination of capital cost in wastewater treatment installations operating under inflow characteristics uncertainty. For this purpose, a methodological framework, under the form of an algorithmic procedure, has been designed/developed and successfully implemented in two cases of biological processing under steady state conditions. The results obtained are in satisfactory approximation with industrial data. Moreover, mathematical formulae have been derived for determining capital cost when processing takes place under unsteady state conditions; in this case, numerical approximation is necessary, since the expressions obtained have not analytic solution. Last, the influence of certain technical parameters on minimum capital cost is discussed.
Directory of Open Access Journals (Sweden)
Orlov A. I.
2015-05-01
Full Text Available Estimates of the errors of the characteristics of financial flows of investment projects are needed to make adequate management decisions, particularly in the rocket and the space industry. Organizational-economic approaches to the estimations of the feasibility of innovation-investment projects to create rocket and space technologies require intensive use of numerical characteristics of the financial flows of long-term projects of this type. In organizational-economic support for control problems in the aerospace industry we must provide the need to obtain the estimates of the errors of the characteristics of financial flows. Such estimates are an integral part of the organizational-economic support of innovation activity in the aerospace industry. They can be compared with the predictions interval, i.e. confidence estimation of predictive values. Half the length of the confidence interval is the prediction error estimate. In this article we give the new method for estimating the errors of the main characteristics of the investment projects. We focus on the net present value called NPV. Our method of estimation of errors is based on the results of statistics interval data, which is an integral part of the system fuzzy interval mathematics. We construct asymptotic theory which corresponds to small deviations of discount coefficients. The error of NPV has been found as the asymptotic notna. With up to infinitesimals of higher orders the error of NPV is a linear function of the maximum possible error of discount coefficients
Analysis on Biomechanical Characteristics of Post-operational Vertebral C5-C6 Segments
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Heqiang Tian
2016-03-01
Full Text Available Both anterior cervical decompression and fusion (ACDF and artificial cervical disc replacement (ACDR have obvious advantages in the treatment of cervical spondylosis. To analyze the operation results, it is absolutely necessary to study the biomechanics of the movement range of post-operational vertebral C5-C6 segments, especially the biomechanical characteristics in cervical tissues in actual movements. In this study, using the human vertebral 3D graph gained by imaging diagnosis (CT, a vertebral solid model is established by the 3D reconstruction algorithm and reverse engineering technology. After that, with cervical soft tissue structure added to the solid model and set with a joint contact mechanism, a finite element model with a complete, accurate cervical C5-C6 kinematic unit is constructed, based on relevant physiological anatomical knowledge. This model includes vertebral segments, an intervertebral disc, ligament and zygopophysis in the cervical C5-C6 kinematic unit. In the created vertebral finite element model, the model is amended, referring to ACDF and ACDR, and the load and constraint are applied to a normal group, a fusion group and a displacement group, so as to analyze the biomechanical characteristics of the cervical vertebra after ACDF and ACDR. By comparing the finite element simulation results of different surgeries, this paper is intended to evaluate the functions and biomechanical behaviors of the post-operational vertebra, and explore the influence of the operation on the biomechanical stability of the cervical vertebra. This will provide theoretical guidance for implementation and optimization of ACDF and ACDR.
Energy Technology Data Exchange (ETDEWEB)
Kongpiboolkid, Watcharapon; Mongkolnavin, Rattachat [Department of Physics, Facuty of Science, Chulalongkorn University, Bangkok (Thailand); Plasma Technology and Nuclear Fusion Research Unit, Chulalongkorn University, Bangkok (Thailand)
2015-04-24
Non-thermal properties of Argon glow discharge operating with various operating pressures were measured and presented in this work. The Argon plasma is produced by a parallel conducting electrodes coupling with a high voltage AC power supply. The power supply can generate high AC voltage at various frequencies. The frequencies for the operation are in the range of a few kHz. The system is capable of generating electric field between the two metal electrodes discharge system. The characteristics of plasma produced were measured by optical emission spectroscopy (OES) technique where electron temperature (T{sub e}) and electron number density (n{sub e}) can be determined by line intensity ratio method. The value of electron number density was then determined from the Saha-Eggert equation. Our results show that the electron number density of the discharge obtained is of the order of 10{sup −17} − 10{sup −18} m{sup −3} where the electron temperature is between 1.00−2.00 eV for various operating frequencies used which are in good agreement with similar results published earlier.
Nair, T R Gopalakrishnan
2011-01-01
The continued existence of any software industry depends on its capability to develop nearly zero-defect product, which is achievable through effective defect management. Inspection has proven to be one of the promising techniques of defect management. Introductions of metrics like, Depth of Inspection (DI, a process metric) and Inspection Performance Metric (IPM, a people metric) enable one to have an appropriate measurement of inspection technique. This article elucidates a mathematical approach to estimate the IPM value without depending on shop floor defect count at every time. By applying multiple linear regression models, a set of characteristic coefficients of the team is evaluated. These coefficients are calculated from the empirical projects that are sampled from the teams of product-based and service-based IT industries. A sample of three verification projects indicates a close match between the IPM values obtained from the defect count (IPMdc) and IPM values obtained using the team coefficients usi...
Estimation of the RF Characteristics of Absorbing Materials in Broad RF Frequency Ranges
Fandos, R
2008-01-01
Absorbing materials are very often used in RF applications. Their electromagnetic characteristics (relative permittivity Îµr, loss tangent tan Î´ and conductivity Ï) are needed in order to obtain a high-quality design of the absorbing pieces in the frequency range of interest. Unfortunately, suppliers often do not provide these quantities. A simple technique to determine them, based on the RF measurement of the disturbance created by the insertion of a piece of absorber in a waveguide, is presented in this note. Results for samples of two different materials, silicon carbide and aluminum nitride are presented. While the former has a negligible conductivity at the working frequencies, the conductivity of the latter has to be taken into account in order to obtain a meaningful estimation of Îµr and tan Î´. The equations of Kramers & Kronig have been applied to the data as a cross check, confirming the results.
Hoell, Simon; Omenzetter, Piotr
2016-04-01
Fueled by increasing demand for carbon neutral energy, erections of ever larger wind turbines (WTs), with WT blades (WTBs) with higher flexibilities and lower buckling capacities lead to increasing operation and maintenance costs. This can be counteracted with efficient structural health monitoring (SHM), which allows scheduling maintenance actions according to the structural state and preventing dramatic failures. The present study proposes a novel multi-step approach for vibration-based structural damage localization and severity estimation for application in operating WTs. First, partial autocorrelation coefficients (PACCs) are estimated from vibrational responses. Second, principal component analysis is applied to PACCs from the healthy structure in order to calculate scores. Then, the scores are ranked with respect to their ability to differentiate different damage scenarios. This ranking information is used for constructing hierarchical adaptive neuro-fuzzy inference systems (HANFISs), where cross-validation is used to identify optimal numbers of hierarchy levels. Different HANFISs are created for the purposes of structural damage localization and severity estimation. For demonstrating the applicability of the approach, experimental data are superimposed with signals from numerical simulations to account for characteristics of operational noise. For the physical experiments, a small scale WTB is excited with a domestic fan and damage scenarios are introduced non-destructively by attaching small masses. Numerical simulations are also performed for a representative fully functional small WT operating in turbulent wind. The obtained results are promising for future applications of vibration-based SHM to facilitate improved safety and reliability of WTs at lower costs.
Directory of Open Access Journals (Sweden)
Satoshi Suzuki
2013-01-01
Full Text Available For an establishment of a skill evaluation method for human support systems, development of an estimating equation of the machine operational skill is presented. Factors of the eye movement such as frequency, velocity, and moving distance of saccade were computed using the developed eye gaze measurement system, and the eye movement features were determined from these factors. The estimating equation was derived through an outlier test (to eliminate nonstandard data and a principal component analysis (to find dominant components. Using a cooperative carrying task (cc-task simulator, the eye movement and operational data of the machine operators were recorded, and effectiveness of the derived estimating equation was investigated. As a result, it was confirmed that the estimating equation was effective strongly against actual simple skill levels (r=0.56–0.84. In addition, effects of internal condition such as fatigue and stress on the estimating equation were analyzed. Using heart rate (HR and coefficient of variation of R-R interval (Cvrri. Correlation analysis between these biosignal indexes and the estimating equation of operational skill found that the equation reflected effects of stress and fatigue, although the equation could estimate the skill level adequately.
Mueller, Astrid; Mitchell, James E; Crosby, Ross D; Gefeller, Olaf; Faber, Ronald J; Martin, Alexandra; Bleich, Stefan; Glaesmer, Heide; Exner, Cornelia; de Zwaan, Martina
2010-12-30
The aim of this study was to estimate the prevalence of compulsive buying and its association with sociodemographic characteristics and depressive symptoms in a nationally representative sample of the German population using the validated German version of the Compulsive Buying Scale (CBS; Faber and O'Guinn, 1992) in order to have a direct comparison with U.S. findings. The point prevalence of compulsive buying in the weighted representative sample (N=2,350) was estimated to be 6.9%. This was somewhat higher than the percentage in the American sample assessed in 2004 (5.8%). No significant difference was found between women and men (6.9% and 6.8%, respectively). Age was inversely related to the prevalence of compulsive buying. Individuals with compulsive buying reported more depressive symptoms assessed via the German version of the Brief Patient Health Questionnaire Mood Scale (PHQ-9). Further research on this topic is needed to establish a clearer delineation of when excessive buying is clinically significant and should be treated and how it could be prevented. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.
IDENTIFICATIONS OF CARCASS CHARACTERISTIC FOR ESTIMATING THE COMPOSITION OF BEEF CARCASS
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H. Hafid
2014-10-01
Full Text Available The research aimed to identify carcass characteristic that can be used for estimating composition ofbeef carcass. It was used 165 Brahman crossbred cattle in this research. Carcass characteristics wereweight of a half cold carcass (WC ranged from 96 to 151 kg, loin eye area (LEA ranged from 22.09 to304.8 mm2, 12th rib fat thickness (FT12 ranged from 0.80 to 2.90 mm, meat ranged from 53.55 to 90.10kg and carcass fat ranged from 5.54 to 39.72 kg. Result showed that a half weight cold carcass as asingle indicator major may be used to predict meat weight and carcass fat with regression linearequation: Meat (kg = 10.64 + 0.49 WC (R2=0.728 and SE=3.58, and Fat (kg = -21.70 + 0.36 WC**(R2=0.582 and SE=3.65. Multiple regression to predict meat weight based on fat percentage of kidney,pelvic and heart (KPH was Meat (kg = 7.99 + 0.58 WC** - 4.41 KPH** (R2=0.751 and SE=3.43.
Institute of Scientific and Technical Information of China (English)
Yang Jiongming; Qin Shuren; Ji Zhong; Guo Yu
2004-01-01
Based on the recently quick-developing time-frequency analysis (TFA) technique and virtual instrument (VI) technique, a virtual instrument in characteristic analysis of rotating machinery is researched and developed successfully. By utilizing instantaneous frequency estimation (IFE) theoretics of TFA technique, and based on IFE of peak searching on the time-frequency spectrum, order analysis (OA) functions is put forward and implemented, such as order spectrum, order spectrum matrix, order tracking, order tracking filtering, and order component extraction, etc. Unlike the home and abroad existing popular characteristic analyzers, which need key phasing devices such as shaft encoder, phase-locked loop (PLL), phase-locked multiple frequency, tachometer, etc, to implement constant angle sampling directly or indirectly, whereas this instrument only uses the vibration signal of rotating machinery to carry out OA. This instrument makes up the shortage of these traditional instruments in analyzing the non-stationary signal of run-up and run-down process of rotating machinery. Therefore, it is a great breakthrough for the existing order analyzers.
Riggio, Valentina; Pesce, Lorenzo L; Morreale, Salvatore; Portolano, Baldassare
2013-06-01
Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would optimally discriminate between healthy and infected udders. Milk samples (n=1357) were collected from 684 sheep in four flocks. The prevalence of infection, as determined by positive bacterial culture was 0.36, 87.7% of which were minor and 12.3% major pathogens. Of the culture negative samples, 83.7% had an SCCCMT results were evaluated, the estimated area under the ROC curve was greater for glands infected with major compared to minor pathogens (0.88 vs. 0.73), whereas the area under the curve considering all pathogens was similar to the one for minor pathogens (0.75). The estimated optimal thresholds were 3.00 (CMT), 2.81 (SCS for the whole sample), 2.81 (SCS for minor pathogens), and 3.33 (SCS for major pathogens). These correctly classified, respectively, 69.0%, 73.5%, 72.6% and 91.0% of infected udders in the samples. The CMT appeared only to discriminate udders infected with major pathogens. In this population, SCS appeared to be the best indirect test of the bacteriological status of the udder. Copyright © 2012 Elsevier Ltd. All rights reserved.
Magaril, Elena
2016-04-01
The environmental and operational characteristics of motor transport, one of the main consumers of motor fuel and source of toxic emissions, soot, and greenhouse gases, are determined to a large extent by the fuel quality which is characterized by many parameters. Fuel density is one of these parameters and it can serve as an indicator of fuel quality. It has been theoretically substantiated that an increased density of motor fuel has a negative impact both on the environmental and operational characteristics of motor transport. The use of fuels with a high density leads to an increase in carbonization within the engine, adversely affecting the vehicle performance and increasing environmental pollution. A program of technological measures targeted at reducing the density of the fuel used was offered. It includes a solution to the problem posed by changes in the refining capacities ratio and the temperature range of gasoline and diesel fuel boiling, by introducing fuel additives and adding butanes to the gasoline. An environmental tax has been developed which allows oil refineries to have a direct impact on the production of fuels with improved environmental performance, taking into account the need to minimize the density of the fuel within a given category of quality.
Barrett, Harrison H; Wilson, Donald W; Kupinski, Matthew A; Aguwa, Kasarachi; Ewell, Lars; Hunter, Robert; Müller, Stefan
2010-01-01
This paper presents a general framework for assessing imaging systems and image-analysis methods on the basis of therapeutic rather than diagnostic efficacy. By analogy to receiver operating characteristic (ROC) curves, it utilizes the Therapy Operating Characteristic or TOC curve, which is a plot of the probability of tumor control vs. the probability of normal-tissue complications as the overall level of a radiotherapy treatment beam is varied. The proposed figure of merit is the area under the TOC, denoted AUTOC. If the treatment planning algorithm is held constant, AUTOC is a metric for the imaging and image-analysis components, and in particular for segmentation algorithms that are used to delineate tumors and normal tissues. On the other hand, for a given set of segmented images, AUTOC can also be used as a metric for the treatment plan itself. A general mathematical theory of TOC and AUTOC is presented and then specialized to segmentation problems. Practical approaches to implementation of the theory in both simulation and clinical studies are presented. The method is illustrated with a a brief study of segmentation methods for prostate cancer.
Investigation on Operational Unsteady Characteristics of CPL：The Effects of Evaporator and Reservoir
Institute of Scientific and Technical Information of China (English)
QuWei; HouZengqi; 等
1999-01-01
Capillary Pumped Loop(CPL) is a two phase closed system.The two main components of CPL,both evaporator and reservoir are generally believed to play significant roles in its unsteady operation.In this paper,experimental and theoretical investigations are carried out on the influences of unsteady characteristics of both of them,The previous analytical results show that there is a pressure oscillation source in the evaporator and the internal oscillation frequency can be obtained .The reservoir also has an unsteady characteristics,when the reservoir line has a smaller damping value,there will be a self-oscillation of pressure in the reservoir ,and its analytical frequencies are normally one or two quantities bigger than the inherent frequencies of the evaporator.In order to keep CPL operate steadily,on one hand,the structure of evaporator must be increased to make the coninuous generated vapor flow out the wick easily,on the other hand,the return liquid ought to be subcooled enough to the reservoir temperature set value.
Preliminary estimates of Gulf Stream characteristics from TOPEX data and a precise gravimetric geoid
Rapp, Richard H.; Smith, Dru A.
1994-01-01
TOPEX sea surface height data has been used, with a gravimetric geoid, to calculate sea surface topography across the Gulf Stream. This topography was initially computed for nine tracks on cycles 21 to 29. Due to inaccurate geoid undulations on one track, results for eight tracks are reported. The sea surface topography estimates were used to calculate parameters that describe Gulf Stream characteristics from two models of the Gulf Stream. One model was based on a Gaussian representation of the velocity while the other was a hyperbolic representation of velocity or the sea surface topography. The parameters of the Gaussian velocity model fit were a width parameter, a maximum velocity value, and the location of the maximum velocity. The parameters of the hyperbolic sea surface topography model were the width, the height jump, position, and sea surface topography at the center of the stream. Both models were used for the eight tracks and nine cycles studied. Comparisons were made between the width parameters, the maximum velocities, and the height jumps. Some of the parameter estimates were found to be highly (0.9) correlated when the hyperbolic sea surface topography fit was carried out, but such correlations were reduced for either the Gaussian velocity fits or the hyperbolic velocity model fit. A comparison of the parameters derived from 1-year TOPEX data showed good agreement with values derived by Kelly (1991) using 2.5 years of Geosat data near 38 deg N, 66 deg W longitude. Accuracy of the geoid undulations used in the calculations was of order of +/- 16 cm with the accuracy of a geoid undulation difference equal to +/- 15 cm over a 100-km line in areas with good terrestrial data coverage. This paper demonstrates that our knowledge or geoid undulations and undulation differences, in a portion of the Gulf Stream region, is sufficiently accurate to determine characteristics of the jet when used with TOPEX altimeter data. The method used here has not been shown to
Preliminary estimates of Gulf Stream characteristics from TOPEX data and a precise gravimetric geoid
Rapp, Richard H.; Smith, Dru A.
1994-01-01
TOPEX sea surface height data has been used, with a gravimetric geoid, to calculate sea surface topography across the Gulf Stream. This topography was initially computed for nine tracks on cycles 21 to 29. Due to inaccurate geoid undulations on one track, results for eight tracks are reported. The sea surface topography estimates were used to calculate parameters that describe Gulf Stream characteristics from two models of the Gulf Stream. One model was based on a Gaussian representation of the velocity while the other was a hyperbolic representation of velocity or the sea surface topography. The parameters of the Gaussian velocity model fit were a width parameter, a maximum velocity value, and the location of the maximum velocity. The parameters of the hyperbolic sea surface topography model were the width, the height jump, position, and sea surface topography at the center of the stream. Both models were used for the eight tracks and nine cycles studied. Comparisons were made between the width parameters, the maximum velocities, and the height jumps. Some of the parameter estimates were found to be highly (0.9) correlated when the hyperbolic sea surface topography fit was carried out, but such correlations were reduced for either the Gaussian velocity fits or the hyperbolic velocity model fit. A comparison of the parameters derived from 1-year TOPEX data showed good agreement with values derived by Kelly (1991) using 2.5 years of Geosat data near 38 deg N, 66 deg W longitude. Accuracy of the geoid undulations used in the calculations was of order of +/- 16 cm with the accuracy of a geoid undulation difference equal to +/- 15 cm over a 100-km line in areas with good terrestrial data coverage. This paper demonstrates that our knowledge or geoid undulations and undulation differences, in a portion of the Gulf Stream region, is sufficiently accurate to determine characteristics of the jet when used with TOPEX altimeter data. The method used here has not been shown to
Using operational data to estimate the reliable yields of water-supply wells
Misstear, Bruce D. R.; Beeson, Sarah
The reliable yield of a water-supply well depends on many different factors, including the properties of the well and the aquifer; the capacities of the pumps, raw-water mains, and treatment works; the interference effects from other wells; and the constraints imposed by ion licences, water quality, and environmental issues. A relatively simple methodology for estimating reliable yields has been developed that takes into account all of these factors. The methodology is based mainly on an analysis of water-level and source-output data, where such data are available. Good operational data are especially important when dealing with wells in shallow, unconfined, fissure-flow aquifers, where actual well performance may vary considerably from that predicted using a more analytical approach. Key issues in the yield-assessment process are the identification of a deepest advisable pumping water level, and the collection of the appropriate well, aquifer, and operational data. Although developed for water-supply operators in the United Kingdom, this approach to estimating the reliable yields of water-supply wells using operational data should be applicable to a wide range of hydrogeological conditions elsewhere. Résumé La productivité d'un puits capté pour l'adduction d'eau potable dépend de différents facteurs, parmi lesquels les propriétés du puits et de l'aquifère, la puissance des pompes, le traitement des eaux brutes, les effets d'interférences avec d'autres puits et les contraintes imposées par les autorisations d'exploitation, par la qualité des eaux et par les conditions environnementales. Une méthodologie relativement simple d'estimation de la productivité qui prenne en compte tous ces facteurs a été mise au point. Cette méthodologie est basée surtout sur une analyse des données concernant le niveau piézométrique et le débit de prélèvement, quand ces données sont disponibles. De bonnes données opérationnelles sont particuli
Hallock, Ashley K.; Polzin, Kurt A.; Kimberlin, Adam C.; Perdue, Kevin A.
2012-01-01
Operational characteristics of two separate inductive thrusters with conical theta pinch coils of different cone angles are explored through thrust stand measurements and time- integrated, unfiltered photography. Trends in impulse bit measurements indicate that, in the present experimental configuration, the thruster with the inductive coil possessing a smaller cone angle produced larger values of thrust, in apparent contradiction to results of a previous thruster acceleration model. Areas of greater light intensity in photographs of thruster operation are assumed to qualitatively represent locations of increased current density. Light intensity is generally greater in images of the thruster with the smaller cone angle when compared to those of the thruster with the larger half cone angle for the same operating conditions. The intensity generally decreases in both thrusters for decreasing mass flow rate and capacitor voltage. The location of brightest light intensity shifts upstream for decreasing mass flow rate of propellant and downstream for decreasing applied voltage. Recognizing that there typically exists an optimum ratio of applied electric field to gas pressure with respect to breakdown efficiency, this result may indicate that the optimum ratio was not achieved uniformly over the coil face, leading to non-uniform and incomplete current sheet formation in violation of the model assumption of immediate formation where all the injected propellant is contained in a magnetically-impermeable current sheet.
Hallock, Ashley K.; Polzin, Kurt A.; Kimberlin, Adam C.
2012-01-01
Operational characteristics of two separate inductive thrusters with coils of different cone angles are explored through thrust stand measurements and time-integrated, un- filtered photography. Trends in impulse bit measurements indicate that, in the present experimental configuration, the thruster with the inductive coil possessing a smaller cone angle produced larger values of thrust, in apparent contradiction to results of a previous thruster acceleration model. Areas of greater light intensity in photographs of thruster operation are assumed to qualitatively represent locations of increased current density. Light intensity is generally greater in images of the thruster with the smaller cone angle when compared to those of the thruster with the larger half cone angle for the same operating conditions. The intensity generally decreases in both thrusters for decreasing mass ow rate and capacitor voltage. The location of brightest light intensity shifts upstream for decreasing mass ow rate of propellant and downstream for decreasing applied voltage. Recognizing that there typically exists an optimum ratio of applied electric field to gas pressure with respect to breakdown efficiency, this result may indicate that the optimum ratio was not achieved uniformly over the coil face, leading to non-uniform and incomplete current sheet formation in violation of the model assumption of immediate formation where all the injected propellant is contained in a magnetically-impermeable current sheet.
Characteristics and Neurological Manifestations of Patients with Operated Lumbar Disc Herniation
Directory of Open Access Journals (Sweden)
Amir Mohammad Bazzazi
2014-01-01
Full Text Available Background and aim: Lumbar disk herniation is one of the most common causes of surgery in the spine with a variety of signs and symptoms. Sensory and motor deficits, as well as reflex and autonomic abnormalities may be seen. This study aimed to investigate characteristics and neurological manifestations in a series of operated cases with lumbar disc herniation. Methods: In a retrospective setting, profiles of 163 operated cases with lumbar disc herniation were reviewed. Demographics as well as preoperational sign and symptoms were extracted and evaluated. Results: There were 86 females and 77 males with a mean age of 44.85±0.91 (range: 23-78 years in the studied population. The most common involved levels were L4-L5 and L5-S1, respectively. Low back pain, radicular pain, and positive Lasegue test were documented in 98.2%, 96.9% and 77.3% of the patients, respectively. Sensory, motor and reflexive abnormalities were documented in 66.3%, 51.5% and 19.6% of the cases, respectively. Sphincter and sexual dysfunction was presented in 4.9% and 1.2%, respectively. Conclusion: Clinical and neurological signs of operated patients with lumbar disc herniation in the studied center are not far different from available reports in this regard. Keywords: Lumbar disk herniation; Signs and symptoms; Surgery
Energy Technology Data Exchange (ETDEWEB)
Holden, Helge; Karlsen, Kenneth H.; Lie, Knut-Andreas
1999-10-01
We present and analyze a numerical method for the solution of a class of scalar, multi-dimensional, nonlinear degenerate convection-diffusion equations. The method is based on operator splitting to separate the convective and the diffusive terms in the governing equation. The nonlinear, convective part is solved using front tracking and dimensional splitting, while the nonlinear diffusion equation is solved by a suitable difference scheme. We verify L{sup 1} compactness of the corresponding set of approximate solutions and derive precise entropy estimates. In particular, these results allow us to pass to the limit in our approximations and recover an entropy solution of the problem in question. The theory presented covers a large class of equations. Important subclasses are hyperbolic conservation laws, porous medium type equations, two-phase reservoir flow equations, and strongly degenerate equations coming from the recent theory of sedimentation-consolidation processes. A thorough numerical investigation of the method analyzed in this paper (and similar methods) is presented in a companion paper. (author)
Energy Technology Data Exchange (ETDEWEB)
Seaver, D.A.; Stillwell, W.G.
1983-03-01
This report describes and evaluates several procedures for using expert judgment to estimate human-error probabilities (HEPs) in nuclear power plant operations. These HEPs are currently needed for several purposes, particularly for probabilistic risk assessments. Data do not exist for estimating these HEPs, so expert judgment can provide these estimates in a timely manner. Five judgmental procedures are described here: paired comparisons, ranking and rating, direct numerical estimation, indirect numerical estimation and multiattribute utility measurement. These procedures are evaluated in terms of several criteria: quality of judgments, difficulty of data collection, empirical support, acceptability, theoretical justification, and data processing. Situational constraints such as the number of experts available, the number of HEPs to be estimated, the time available, the location of the experts, and the resources available are discussed in regard to their implications for selecting a procedure for use.
Xiang, Hong; Lü, Xi-Wu; Yang, Fei; Yin, Li-Hong; Zhu, Guang-Can
2011-04-01
In order to explore characteristics of microbial community and operation efficiency in biofilter (biologically-enhanced active filter and biological activated carbon filter) process for drinking water purification, Biolog and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) techniques were applied to analyze the metabolic function and structure of microbial community developing in biofilters. Water quality parameters, such as NH; -N, NO; -N, permanganate index, UV254 and BDOC etc, were determined in inflow and outflow of biofilters for investigation of operation efficiency of the biofilters. The results show that metabolic capacity of microbial community of the raw water is reduced after the biofilters, which reflect that metabolically active microbial communities in the raw water can be intercepted by biofilters. After 6 months operation of biofilters, the metabolic profiles of microbial communities are similar between two kinds of biologically-enhanced active filters, and utilization of carbon sources of microbial communities in the two filters are 73.4% and 75.5%, respectively. The metabolic profiles of microbial communities in two biological activated carbon filters showed significant difference. The carbon source utilization rate of microbial community in granule-activated carbon filter is 79.6%, which is obviously higher than 53.8% of the rate in the columnar activated carbon filter (p water purification efficiency was not significant (p > 0.05). However, in biological activated carbon filters, granule-activated carbon is conducive to microbial growth and reproduction, and the microbial communities in the biofilter present high metabolic activities, and the removal efficiency for NH4(+)-N, permanganate index and BDOC is better than the columnar activated carbon filter(p < 0.05). The results also suggest that operation efficiency of biofilter is related to the metabolic capacity of microbial community in biofilter.
Operational characteristics and analysis of the immersed-Bz diode on RITS-3.
Energy Technology Data Exchange (ETDEWEB)
Bruner, Nichelle " Nicki"
2006-02-01
The immersed-B{sub z} diode is being developed as a high-brightness, flash x-ray radiography source. This diode is a foil-less electron-beam diode with a long, thin, needle-like cathode inserted into the bore of a solenoid. The solenoidal magnetic field guides the electron beam emitted from the cathode to the anode while maintaining a small beam radius. The electron beam strikes a thin, high-atomic-number anode and produces bremsstrahlung. We report on an extensive series of experiments where an immersed-B{sub z} diode was fielded on the RITS-3 pulsed power accelerator, a 3-cell inductive voltage generator that produced peak voltages between 4 and 5 MV, {approx}140 kA of total current, and power pulse widths of {approx}50 ns. The diode is a high impedance device that, for these parameters, nominally conducts {approx}30 kA of electron beam current. Diode operating characteristics are presented and two broadly characterized operating regimes are identified: a nominal operating regime where the total diode current is characterized as classically bipolar and an anomalous impedance collapse regime where the total diode current is in excess of the bipolar limit and up to the full accelerator current. The operating regimes are approximately separated by cathode diameters greater than {approx}3 mm for the nominal regime and less than {approx} 3 mm for the anomalous impedance collapse regime. This report represents a compilation of data taken on RITS-3. Results from key parameter variations are presented in the main body of the report and include cathode diameter, anode-cathode gap, and anode material. Results from supporting parameter variations are presented in the appendices and include magnetic field strength, prepulse, pressure and accelerator variations.
Directory of Open Access Journals (Sweden)
N. Vedachalam
2016-04-01
Full Text Available This paper presents a quantitative approach to operational risk modeling and estimation of safety integrity levels, required for the deep water electric work class remotely operated vehicle with reference to ROSUB6000 developed by the National Institute of Ocean Technology, India. ROSUB6000 is used for carrying out bathymetric surveys, gas hydrate surveys, poly-metallic nodule exploration, salvage operations, and meeting emergency response situations. The system is expected to be in operation for a period of 300h per year, and has to be extremely safe and reliable. Methods and models for the quantitative assessment of operational safety and estimation of safety integrity levels for ROV are seldom available in the deep water intervention industry. The safety instrumented functions implemented in the ROV should be able to meet the SIL requirements of specific mission. This study indicates that the required safety factors are implemented into the design of the state-of-the-art ROV ROSUB 6000, considering IEC 61508/61511 recommendations on Health, Safety and Environment and it is found that the system is able to meet the required SIL for seven identified functions. This paper gives the design and safety engineers in the ROV industry, an overview of the numerical operational risk assessment methods and safety-centered ROV engineering.
Institute of Scientific and Technical Information of China (English)
Li Qi; Gao Zhanbao; Tang Diyin; Li Baoan
2016-01-01
Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL) for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically moni-tored degradation processes with dynamic time-varying operational conditions and condition-specific failure zones. The method assumes that the degradation rate is influenced by specific oper-ational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditions are assumed to evolve as a discrete-time Markov chain (DTMC). The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUL estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with exist-ing methods for the same dataset.
The estimation of analysis error characteristics using an observation systems simulation experiment
Energy Technology Data Exchange (ETDEWEB)
Errico, R.M. [Goddard Earth Sciences and Technology Center, Univ. of Maryland, Baltimore County (United States); Global Modeling and Assimilation Office, Goddard Space Flight Center, Greenbelt, MD (United States); Yang, R. [Science Systems and Applications Inc., Lanham, MD (United States); Global Modeling and Assimilation Office, Goddard Space Flight Center, Greenbelt, MD (United States); Masutani, M.; Woollen, J.S. [National Centers for Environmental Prediction, Camp Springs, MD (United States)
2007-12-15
Observation system simulation experiments (OSSEs) have been performed at the National Centers for Environmental Prediction primarily for the purpose of evaluating the forecast improvement potential of proposed new observation instruments. The simulations have been validated primarily by comparing results from corresponding data denial experiments in both simulated and real data assimilation contexts. Additional validation is presented here using comparisons of some statistics of analysis increments determined from a baseline simulation using the entire suite of observations utilized during a reanalysis for February 1993. By exploiting the availability of a data set representing ''truth'' in the simulations, the background and analysis errors produced for the baseline simulation are computed. Several statistics of these errors are then determined, including time means and variances as functions of location or spherical harmonic wave number, vertical correlations, Kalman gains, and balance as measured by projections onto normal modes. Use of an OSSE in this way is one of the few means of estimating analysis error characteristics. Although these simulation experiments are among the best calibrated ones existing, the additional validation here indicates that some unrealism remains present. With this caveat, several interesting characteristics of analysis error have been revealed. Among these are that: longitudinal variations of error variances in the Northern Hemisphere have a similar range as latitudinal variations; corresponding background and analysis error variances are very similar in most regions so that the Kalman gains are generally small with the notable exception of regions and times well observed by rawindsondes; correlation lengths (both vertical and horizontal) are very similar for background and analysis errors; error variances at horizontal scales shorter than those corresponding to approximately spherical harmonic wavenumber 70 are
Directory of Open Access Journals (Sweden)
Yongfang Wang
2016-11-01
Full Text Available Drought has an important influence on the hydrological cycle, ecological system, industrial and agricultural production, and social life. Based on the different time scales of characteristics of drought variability, the standardized precipitation evapotranspiration index (SPEI, a multi-timescale index with consideration of evaporation, was used in this study to estimate the spatial and temporal variability characteristics of drought. Climatic data from 15 meteorological stations across Horqin Sandy Land during 1964–2013 were used to calculate the SPEI of 1, 3, 6, and 12 months. In order to examine the relationship between droughts and other variables, 10 extreme climate indices were calculated based on the daily precipitation and maximum/mean/minimum temperature data of 15 meteorological stations, and linkages between SPEI-12 and atmosphere indices were established using by the cross wavelet transform method. The results indicated that the climate of Horqin Sandy Land had a tendency towards drought conditions, which is particularly apparent from the year 2000 onwards. During the study period, drought events were frequent in the region. Mild drought occurred in a quarter of the month, with that of moderate, severe, and extreme drought accounting for 0.11, 0.05, and 0.02 of the total months. The spatial trend of multi-timescale drought revealed that there was an increase in the severity of drought throughout Horqin Sandy Land, among which the magnitude in southern parts was larger than that of northern parts. The results also showed that the short time scale drought negatively correlated with precipitation extremes and positively correlated with temperature extremes. Furthermore, the long time scale drought (SPEI-12 was associated with atmosphere indices. Significant resonance periods were found between El Nino southern oscillation (ENSO, the East Asian summer monsoon index (EASMI, and SPEI-12.
Tanenbaum, Sandra J
2012-08-01
Consumer-operated service organizations (COSOs) are independent organizations whose administrative and financial control resides with consumers. Based on a 2008 mail survey and followup interviews conducted in 2009, this study depicts the internal characteristics and external relationships, as well as some relationships between the two, of COSOs in one state. Profiles include on the one hand, governance structures, services provided, sources and levels of funding, etc. and on the other, relationships between COSOs and other actors in the mental health system and the local community. COSOs emerge as more self-governing and community-based than required by certification requirements and as developing internally and externally in tandem. COSOs are not only adjunct or alternative service providers, but also civic associations and loci for the expression of citizenship by mentally ill people.
Characteristic analysis of a water hydraulic pilot-operated pressure-reducing valve
Mao, Xuyao; Hu, Junhua; Wu, Chao; Liu, Yiou; Liu, Yinshui
2017-06-01
Comprehensive characteristics of a seawater hydraulic pilot-operated pressure-reducing valve with constant pressure output were analyzed. A rated pressure of 15MPa and a rated flowrate of 40L/min were offered in the numerical work. Static and dynamic analyses show good behaviors: The settling time is less than 0.2s, the output pressure variation is about 0.3MPa at the maximum when input pressure or flowrate is flucturing, and the steady external leakage is below 0.025L/min. The pilot spring regulates the output pressure and the main spring has an ability to adjust the output pressure variation faintly. The narrow hole diameter of the adjustable damping plugs is negatively related to the respond time. And appropriately raising the spring chamber volume can evidently reduce outlet pressure impact of the valve when input mutations happen.
Xu, Lili; Luo, Shuqian
2010-11-01
Microaneurysms (MAs) are the first manifestations of the diabetic retinopathy (DR) as well as an indicator for its progression. Their automatic detection plays a key role for both mass screening and monitoring and is therefore in the core of any system for computer-assisted diagnosis of DR. The algorithm basically comprises the following stages: candidate detection aiming at extracting the patterns possibly corresponding to MAs based on mathematical morphological black top hat, feature extraction to characterize these candidates, and classification based on support vector machine (SVM), to validate MAs. Feature vector and kernel function of SVM selection is very important to the algorithm. We use the receiver operating characteristic (ROC) curve to evaluate the distinguishing performance of different feature vectors and different kernel functions of SVM. The ROC analysis indicates the quadratic polynomial SVM with a combination of features as the input shows the best discriminating performance.
Karakaya, Jale; Karabulut, Erdem; Yucel, Recai M
Modern statistical methods using incomplete data have been increasingly applied in a wide variety of substantive problems. Similarly, receiver operating characteristic (ROC) analysis, a method used in evaluating diagnostic tests or biomarkers in medical research, has also been increasingly popular problem in both its development and application. While missing-data methods have been applied in ROC analysis, the impact of model mis-specification and/or assumptions (e.g. missing at random) underlying the missing data has not been thoroughly studied. In this work, we study the performance of multiple imputation (MI) inference in ROC analysis. Particularly, we investigate parametric and non-parametric techniques for MI inference under common missingness mechanisms. Depending on the coherency of the imputation model with the underlying data generation mechanism, our results show that MI generally leads to well-calibrated inferences under ignorable missingness mechanisms.
Dynamic estimator for determining operating conditions in an internal combustion engine
Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob
2016-01-05
Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.
Chen, Hao; Jia, Pu; Bao, Li; Feng, Fei; Yang, He; Li, Jin-Jun; Tang, Hai
2015-01-01
Background: The cross-section of thoracolumbar vertebral body is kidney-shaped with depressed posterior boundary. The anterior wall of the vertebral canal is separated from the posterior wall of the vertebral body on the lateral X-ray image. This study was designed to determine the sagittal distance between the anterior border of the vertebral canal and the posterior border of the vertebral body (DBCV) and to analyze the potential role of DBCV in the estimation of cement leakage during percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). Methods: We retrospectively recruited 233 patients who had osteoporotic vertebral compression fractures and were treated with PVP or PKP. Computed tomography images of T11–L2 normal vertebrae were measured to obtain DBCV. The distance from cement to the posterior wall of the vertebral body (DCPW) of thoracolumbar vertebrae was measured from C-arm images. The selected vertebrae were divided into two groups according to DCPW, with the fracture levels, fracture grades and leakage rates of the two groups compared. A relative operating characteristic (ROC) curve was applied to determine whether the DCPW difference can be used to estimate the degree of cement leakage. The data were processed by statistical software SPSS version 21.0 using independent sample t-test and Chi-square tests. Results: The maximum DBCV was 6.40 mm and the average DBCV was 3.74 ± 0.95 mm. DBCV appeared to be longer in males than in females, but the difference was not statistically significant. The average DCPW of type-B leakage vertebrae (2.59 ± 1.20 mm) was shorter than that of other vertebrae (7.83 ± 2.38 mm, P 6.40 mm for type-C and type-S, but much higher for type-B. ROC curve revealed that DCPW only has a predictive value for type-B leakage (area under the curve: 0.98, 95% confidence interval: 0.95–0.99, P < 0.001), and when the cut-off value was 4.05 mm, the diagnostic sensitivity and the specificity were 94.87% and 93
Directory of Open Access Journals (Sweden)
Islam M. Rafizul
2012-01-01
Full Text Available This study demonstrates the influence of lysimeter operational condition and tropical seasonal variation of leachate characteristics generated from municipal solid waste (MSW deposited in landfill lysimeter at KUET campus, Bangladesh. Three different situations of landfill were considered here as well as both the open dump lysimeter-A having a base liner and sanitary landfill lysimeter-B and C at two different types of cap liner were simulated. The leachate characteristics, leachate generation and climatic influence parameter had been continually monitored, from June 2008 to May 2010. This period covers both dry and rainy season. The leachate generation followed the rainfall pattern and the open dump lysimeter-A without top cover was recorded to have the highest leachate generation. Moreover, the open dump lysimeter-A had lower concentration and load of total kjeldahl nitrogen (TKN, ammonia nitrogen (NH4-N and dissolved organic carbon (DOC, while chemical oxygen demand (COD and biological oxygen demand (BOD5 concentration were higher compared with sanitary lysimeter-B and C. On the other hand, sanitary lysimeter-B, not only had lowest leachate generation, but also produced reasonably low COD and BOD5 concentration compared with open dump lysimeter-A. Based on evaluated results, it was also concluded that metal concentrations which were comparatively higher in leachate of open dump lysimeter were Ca and K, however, the heavy metal concentrations of Cd, Cu, Zn and Mn, and those apparently lower were metals of Na, Mg and Fe as well as heavy metals of Cr, Pb and Ni. However, significant release of heavy metals under open dump lysimeter was observed compared to sanitary lysimeter. Moreover, meaningful correlation between DOC and leaching of Cu and Pb was observed. Result reveals that lysimeter operational mode had direct effect on leachate quality. Finally, it can be concluded that the knowledge of leachate quality will be useful in planning and
Operational Characteristics and Plasma Measurements in a Low-Energy FARAD Thruster
Polzin, K. A.; Best, S.; Rose, M. F.; Miller, R.; Owens, T.
2008-01-01
Pulsed inductive plasma accelerators are spacecraft propulsion devices in which energy is stored in a capacitor and then discharged through an inductive coil. The device is electrodeless, inducing a plasma current sheet in propellant located near the face of the coil. The propellant is accelerated and expelled at a high exhaust velocity (order of 10 km/s) through the interaction of the plasma current with an induced magnetic field. The Faraday Accelerator with RF-Assisted Discharge (FARAD) thruster is a type of pulsed inductive plasma accelerator in which the plasma is preionized by a mechanism separate from that used to form the current sheet and accelerate the gas. Employing a separate preionization mechanism in this manner allows for the formation of an inductive current sheet at much lower discharge energies and voltages than those found in previous pulsed inductive accelerators like the Pulsed Inductive Thruster (PIT). In this paper, we present measurements aimed at quantifying the thruster's overall operational characteristics and providing additional insight into the nature of operation. Measurements of the terminal current and voltage characteristics during the pulse help quantify the output of the pulsed power train driving the acceleration coil. A fast ionization gauge is used to measure the evolution of the neutral gas distribution in the accelerator prior to a pulse. The preionization process is diagnosed by monitoring light emission from the gas using a photodiode, and a time-resolved global view of the evolving, accelerating current sheet is obtained using a fast-framing camera. Local plasma and field measurements are obtained using an array of intrusive probes. The local induced magnetic field and azimuthal current density are measured using B-dot probes and mini-Rogowski coils, respectively. Direct probing of the number density and electron temperature is performed using a triple probe.
Incidence of kala-azar in Nepal: estimating the effects of individual and household characteristics.
Adhikari, Shiva Raj; Supakankunti, Siripen; Khan, M Mahmud
2010-11-01
Kala-azar (KA) remains a major public health problem in Nepal. The disease is preventable, but various environmental, socioeconomic, health care and health behaviour related variables affect its transmission. Household or individual related factors determine the magnitude and direction of impacts of these factors. Data were collected from clinically diagnosed KA patients and non-KA patients from hospitals in Nepal. The hospitals are located in the highest KA incidence rate districts. Logistic regressions are used to identify individual and household characteristics affecting the probability of having KA by estimating models with and without the introduction of interaction terms. Poverty incidence, being a member of disadvantaged population group, size of family and literacy are important in explaining the likelihood of having KA. Poverty directly influences the likelihood of KA and modifies the magnitude and direction of the effects of other variables. The traditional approach of controlling KA at the community level should be complemented by poverty alleviation and other developmental activities to ensure rapid decline and eradication of KA. Poverty and illiteracy magnifies the problem of KA at the community level and simultaneous implementation of KA control interventions with effective poverty alleviation strategies is likely to be much more effective than the traditional disease control program alone. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
Ren, Nan-qi; Tang, Jing; Gong, Man-li
2006-06-01
A kind of granular activated carbon, whose granular size is no more than 2mm and specific gravity is 1.54g/cm3, was used as the support carrier to allow retention of activated sludge within a continuous stirred-tank reactor (CSTR) using molasses wastewater as substrate for bio-hydrogen production. Continuous operation characteristics and operational controlling strategy of the enhanced continuous bio-hydrogen production system were investigated. It was indicated that, support carriers could expand the activity scope of hydrogen production bacteria, make the system fairly stable in response to organic load impact and low pH value (pH reactor at low HRT. The reactor with ethanol-type fermentation achieved an optimal hydrogen production rate of 0.37L/(g x d), while the pH value ranged from 3.8 to 4.4, and the hydrogen content was approximately 40% approximately 57% of biogas. It is effective to inhibit the methanogens by reducing the pH value of the bio-hydrogen production system, consequently accelerate the start-up of the reactor.
Choi, Hyeok; Zhang, Kai; Dionysiou, Dionysios D; Oerther, Daniel B; Sorial, George A
2006-06-01
Biofouling control is considered to be a major challenge in operating membrane bioreactors (MBRs) for the treatment of wastewater. This study examined the impact of biological, chemical, and physical properties of activated sludge on membrane filtration performance in laboratory-scale MBRs. Sludges with different microbial communities were produced using pseudo-continuous stirred-tank reactors and pseudo-plug flow reactors treating a synthetic paper mill wastewater. Various filtration resistances were used to investigate membrane fouling characteristics, and molecular biology tools targeting 16S ribosomal DNA gene sequences were used to identify predominant bacterial populations in the sludges or attached to the fouled membranes. Filtration experiments using axenic cultures of Escherichia coli, Acinetobacter calcoaceticus, and Gordonia amarae were also performed to better understand the initiation and development of biofouling. The results showed that the tendency of membranes to biofoul depended upon membrane operating conditions as well as the properties of the activated sludge in the MBR systems. Specific bacterial populations, which were not dominant in the activated sludges, were selectively accumulated on the membrane surface leading to the development of irreversible biofouling.
Directory of Open Access Journals (Sweden)
Li Qi
2016-06-01
Full Text Available Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically monitored degradation processes with dynamic time-varying operational conditions and condition-specific failure zones. The method assumes that the degradation rate is influenced by specific operational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditions are assumed to evolve as a discrete-time Markov chain (DTMC. The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUL estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with existing methods for the same dataset.
Energy Technology Data Exchange (ETDEWEB)
Holttinen, Hannele; Kiviluoma, Juha; McCann, John; Clancy, Matthew; Millgan, Michael; Pineda, Ivan; Eriksen, Peter Borre; Orths, Antje; Wolfgang, Ove
2015-10-05
This paper presents ways of estimating CO2 reductions of wind power using different methodologies. Estimates based on historical data have more pitfalls in methodology than estimates based on dispatch simulations. Taking into account exchange of electricity with neighboring regions is challenging for all methods. Results for CO2 emission reductions are shown from several countries. Wind power will reduce emissions for about 0.3-0.4 MtCO2/MWh when replacing mainly gas and up to 0.7 MtCO2/MWh when replacing mainly coal powered generation. The paper focuses on CO2 emissions from power system operation phase, but long term impacts are shortly discussed.
Kroetz, P.; Ruehl, A.; Calendron, A.-L.; Chatterjee, G.; Cankaya, H.; Murari, K.; Kärtner, F. X.; Hartl, I.; Miller, R. J. D.
2017-04-01
We present a comprehensive study of laser pulse amplification of Ho:YLF regenerative amplifiers (RAs) with respect to operation regimes, gain dynamics, and output pulse stability. The findings are expected to be more generic than for this specific gain material. Operation regimes are distinguished with respect to pulse energy and the appearance of pulse instability, and are studied as a function of the repetition rate, seed energy, and pump intensity. The corresponding gain dynamics are presented, identifying highly stable operation points related to high-gain build-up during pumping and high-gain depletion during pulse amplification. Such operation points are studied numerically and experimentally as a function of several parameters, thereby achieving, for our Ho:YLF RA, highly stable output pulses with measured fluctuations of only 0.19% (standard deviation).
Interior Lp-estimates for elliptic and parabolic Schr\\"odinger type operators and local Ap-weights
Cardoso, Isolda; Viola, Pablo; Viviani, Beatriz
2015-01-01
Let Omega be a non-empty open proper and connected subset of R^n. Consider p elliptic Schr\\"odinger type operator L_{E}u=A_{E}u+V in Omega, and the linear parabolic operator L_{P}u=A_{P}u+Vu in Omega x (0,T), where the coefficients of A_{E} and A_{P} are in VMO and the potential V satisfies a reverse-H\\"older condition. The aim of this paper is to obtain a priori estimates for the operators L_{E} and L_{P} in weighted Sobolev spaces involving the distance to the boundary and weights in a loca...
Santillana, Mauricio; Zhang, Lin; Yantosca, Robert
2016-01-01
We present upper bounds for the numerical errors introduced when using operator splitting methods to integrate transport and non-linear chemistry processes in global chemical transport models (CTM). We show that (a) operator splitting strategies that evaluate the stiff non-linear chemistry operator at the end of the time step are more accurate, and (b) the results of numerical simulations that use different operator splitting strategies differ by at most 10%, in a prototype one-dimensional non-linear chemistry-transport model. We find similar upper bounds in operator splitting numerical errors in global CTM simulations.
Bordoni, M.; Bittelli, M.; Valentino, R.; Chersich, S.; Meisina, C.
2017-09-01
In this work, Soil Water Characteristic Curves (SWCCs) were reconstructed through simultaneous field measurements of soil pore water pressure and water content. The objective was to evaluate whether field-based monitoring can allow for the improvement of the accuracy in SWCCs estimation with respect to the use of laboratory techniques. Moreover, field assessment of SWCCs allowed to: a) quantify the hydrological hysteresis affecting SWCCs through field data; b) analyze the effect of different temporal resolution of field measures; c) highlight the differences in SWCCs reconstructed for a particular soil during different hydrological years; d) evaluate the reliability of field reconstructed SWCCs, by the comparison between assessed and measured trends of a component of the soil water balance. These aspects were fundamental for assessing the reliability of the field reconstructed SWCCs. Field data at two Italian test-sites were measured. These test-sites were used to evaluate the goodness of field reconstructed SWCCs for soils characterized by different geomorphological, geological, physical and pedological features. Field measured or laboratory measured SWCCs data of 5 soil horizons (3 in a predominantly silty soil, 2 in a predominantly clayey one) were fitted by Van Genuchten model. Different field drying and wetting periods were identified, based on monthly meteorological conditions, in terms of rainfall and evapotranspiration amounts, of different cycles. This method allowed for a correct discrimination of the main drying and the main wetting paths from field data related and for a more reliable quantification of soil hydrological properties with respect to laboratory methodologies. Particular patterns of changes in SWCCs forms along depth could be also identified. Field SWCCs estimation is not affected by the temporal resolution of the acquisition (hours or days), as testified by similar values of Van Genuchten equation fitting parameters. Instead, hourly data
Characteristics and Diurnal Cycle of GPM Rainfall Estimates over the Central Amazon Region
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Rômulo Oliveira
2016-06-01
Full Text Available Studies that investigate and evaluate the quality, limitations and uncertainties of satellite rainfall estimates are fundamental to assure the correct and successful use of these products in applications, such as climate studies, hydrological modeling and natural hazard monitoring. Over regions of the globe that lack in situ observations, such studies are only possible through intensive field measurement campaigns, which provide a range of high quality ground measurements, e.g., CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GlobAl Precipitation Measurement and GoAmazon (Observations and Modeling of the Green Ocean Amazon over the Brazilian Amazon during 2014/2015. This study aims to assess the characteristics of Global Precipitation Measurement (GPM satellite-based precipitation estimates in representing the diurnal cycle over the Brazilian Amazon. The Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG and the Goddard Profiling Algorithm—Version 2014 (GPROF2014 algorithms are evaluated against ground-based radar observations. Specifically, the S-band weather radar from the Amazon Protection National System (SIPAM, is first validated against the X-band CHUVA radar and then used as a reference to evaluate GPM precipitation. Results showed satisfactory agreement between S-band SIPAM radar and both IMERG and GPROF2014 algorithms. However, during the wet season, IMERG, which uses the GPROF2014 rainfall retrieval from the GPM Microwave Imager (GMI sensor, significantly overestimates the frequency of heavy rainfall volumes around 00:00–04:00 UTC and 15:00–18:00 UTC. This overestimation is particularly evident over the Negro, Solimões and Amazon rivers due to the poorly-calibrated algorithm over water surfaces. On the other hand, during the dry season, the IMERG product underestimates mean precipitation in comparison to the S-band SIPAM
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E. V. Kalentionok
2015-01-01
Full Text Available Most techniques of the fault location based on the one-side measurement of the emergency mode characteristics use the short-circuit steady-regime parameters in the fundamental mode frequency. This approach compels to seek additional devices for tuning out the loadings of transformer-substations. Besides, it is susceptible to the nonlinearity effect of closed-circuit arc in the fault location which significantly reduces the accuracy of the remote location of the failure.For estimating the distance to the location of interphase failure on the aerial distributive transmission lines the article proposes a new technique employing the harmonic components of the operating emergency parameters. The algorithm of the present method realization includes: taking down oscillograms of the emergency-mode parameter values (e. g. in doublephase failure – the short-circuit current, the linear voltage between the faulty phases with necessary discretization interval; expansion of the operating emergency parameters in a Fourier series (realized with a quick Fourier expansion algorithm; estimating the distance to the fault location by the analytical expression; performing the statistical analysis of a row of distance values and finding the most probable distance to the fault location.For effectiveness investigation of the proposed method of trapping harmonic components the paper considers a 10 kV distributive electrical grid feeding nine transformer substations. The authors performed calculation of normal and emergency modes utilizing computer program MatLab in dynamic simulating environment Simulink. The arc is represented by a block describing the linearized dynamic volt-ampere characteristic of the arc. The built characteristic curves demonstrate dependence of the fault-location distance value from the frequency at which this value is obtained and the number if its reiterations. Based on the calculations, the authors establish that the accuracy of the distance
Directory of Open Access Journals (Sweden)
Roman Urban
2003-08-01
Full Text Available We consider the Green functions for second order non-coercive differential operators on homogeneous manifolds of negative curvature, being a semi-direct product of a nilpotent Lie group $N$ and $A=mathbb{R}^+$. We obtain estimates for the mixed derivatives of the Green functions that complements a previous work by the same author [17].
McEnery, J. A.; Jitkajornwanich, K.
2012-12-01
This presentation will describe the methodology and overall system development by which a benchmark dataset of precipitation information has been used to characterize the depth-area-duration relations in heavy rain storms occurring over regions of Texas. Over the past two years project investigators along with the National Weather Service (NWS) West Gulf River Forecast Center (WGRFC) have developed and operated a gateway data system to ingest, store, and disseminate NWS multi-sensor precipitation estimates (MPE). As a pilot project of the Integrated Water Resources Science and Services (IWRSS) initiative, this testbed uses a Standard Query Language (SQL) server to maintain a full archive of current and historic MPE values within the WGRFC service area. These time series values are made available for public access as web services in the standard WaterML format. Having this volume of information maintained in a comprehensive database now allows the use of relational analysis capabilities within SQL to leverage these multi-sensor precipitation values and produce a valuable derivative product. The area of focus for this study is North Texas and will utilize values that originated from the West Gulf River Forecast Center (WGRFC); one of three River Forecast Centers currently represented in the holdings of this data system. Over the past two decades, NEXRAD radar has dramatically improved the ability to record rainfall. The resulting hourly MPE values, distributed over an approximate 4 km by 4 km grid, are considered by the NWS to be the "best estimate" of rainfall. The data server provides an accepted standard interface for internet access to the largest time-series dataset of NEXRAD based MPE values ever assembled. An automated script has been written to search and extract storms over the 18 year period of record from the contents of this massive historical precipitation database. Not only can it extract site-specific storms, but also duration-specific storms and
Su, Chiu-Wen; Ming-Fang Yen, Amy; Lai, Hongmin; Chen, Hsiu-Hsi; Chen, Sam Li-Sheng
2017-07-28
Background The accuracy of a prediction model for periodontal disease using the community periodontal index (CPI) has been undertaken by using an area receiver operating characteristics (AUROC) curve, but how the uncalibrated CPI, as measured by general dentists trained by periodontists in a large epidemiological study, required for constructing a prediction model that affects its performance has not been researched yet. Methods We conducted a two-stage design by first proposing a validation study to calibrate the CPI between a senior periodontal specialist and trained general dentists who measured CPIs in the main study of a nationwide survey. A Bayesian hierarchical logistic regression model was applied to estimate the non-updated and updated clinical weights used for building up risk scores. How the calibrated CPI affected the performance of the updated prediction model was quantified by comparing the AUROC curves between the original and the updated model. Results The estimates regarding the calibration of CPI obtained from the validation study were 66% and 85% for sensitivity and specificity, respectively. After updating, the clinical weights of each predictor were inflated, and the risk score for the highest risk category was elevated from 434 to 630. Such an update improved the AUROC performance of the two corresponding prediction models from 62.6% (95% CI: 61.7%-63.6%) for the non-updated model to 68.9% (95% CI: 68.0%-69.6%) for the updated one, reaching a statistically significant difference (P periodontal disease as measured by the calibrated CPI derived from a large epidemiological survey.
Toft, Nils; Nielsen, Søren S
2009-11-15
Critical, systematic reviews of available diagnostic test evaluations are a meticulous approach to synthesize evidence about a diagnostic test. However, often the review finds that data quality is poor due to deficiencies in design and reporting of the test evaluations and formal statistical comparisons are discouraged. Even when only simple summary measures are appropriate, the strong correlation between sensitivity and specificity and their dependence on differences in diagnostic threshold across studies, creates the need for tools to summarise properties of the diagnostic test under investigation. This study presents summary receiver operating characteristics (SROC) analysis as a means to synthesize information from diagnostic test evaluation studies. Using data from a review of diagnostic tests for ante mortem diagnosis of paratuberculosis as an illustration, SROC and hierarchical SROC (HSROC) analysis were used to estimate overall diagnostic accuracies of antibody ELISAs for bovine paratuberculosis while accounting for covariates: the target condition (infectious or infected) used in the test evaluation (one for the evaluation of Se and one for Sp); and the type of test (serum vs. milk). The methods gave comparable results (regarding the estimated diagnostic log odds ratio), considering the small sample size and the quality of data. The SROC analysis found a difference in the performance of tests when the target condition for evaluation of Se was infected rather than infectious, suggesting that ELISAs are not suitable for detecting infected cattle. However, the SROC model does not take differences in sample size between study units into account, whereas the HSROC allows for both between and within study variation. Considering the small sample size, more credibility should be given to the results of the HSROC. For both methods the area under the (H)SROC curve was calculated and results were comparable. The conclusion is that while the SROC is simpler and easier
Bera, K.; Farouk, B.; Lee, Y. H.
2001-05-01
A self-consistent two-dimensional radio frequency capacitively coupled glow discharge model has been developed in cylindrical coordinates for a methane discharge using a fluid model. The objective of the study is to identify the effects of design and operating variables of the reactor on the process characteristics such as the deposition rate, uniformity and the quality of the diamond-like-carbon film. The simulations provide insights to charged species dynamics and investigate their effects on the plasma process for a depositing methane discharge. The model includes continuity equations for electrons and positive and negative ions, and energy equation for electrons. Swarm data as a function of electron energy are provided as input to the model. The model predicts the electron density, ion density, and their fluxes and energies to the cathode. The roles of electrons, dominating ions and radicals in a capacitively coupled discharge are investigated. The radical and neutral densities in the discharge are calculated using a gas phase chemistry model. The diamond-like-carbon thin-film deposition rate is predicted using surface chemistry model. The gas phase chemistry model considers diffusion of radicals and neutrals along with creation and loss terms. The surface deposition/etching process involves adsorption-desorption, adsorption layer reaction, ion stitching, direct ion incorporation, etching and carbon sputtering. A systematic parametric study of plasma processing has been performed to identify process parameters to obtain better film deposition/etching on a wafer. The present work shows how plasma equipment simulation can be used for the practical investigation and optimization of a plasma-assisted chemical vapour deposition process. The simultaneous treatment of plasma dynamics and surface processes enables a very precise prediction of the process characteristics in terms of the film deposition rate, uniformity and the quality as functions of discharge control
COMBUSTION CHARACTERISTICS OF DIESEL ENGINE OPERATING ON JATROPHA OIL METHYL ESTER
Directory of Open Access Journals (Sweden)
Doddayaraganalu Amasegoda Dhananjaya
2010-01-01
Full Text Available Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.
Junction temperature estimation method for a 600 V, 30A IGBT module during converter operation
DEFF Research Database (Denmark)
Choi, U. M.; Blaabjerg, F.; Iannuzzo, F.
2015-01-01
This paper proposes an accurate method to estimate the junction temperature using the on-state collector-emitter voltage at high current. By means of the proposed method, the estimation error which comes from the different temperatures of the interconnection materials in the module is compensated...
A New Estimate on the Rate of Convergence of Durrmeyer-Bézier Operators
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Pinghua Wang
2009-01-01
Full Text Available We obtain an estimate on the rate of convergence of Durrmeyer-Bézier operaters for functions of bounded variation by means of some probabilistic methods and inequality techniques. Our estimate improves the result of Zeng and Chen (2000.
Promraksa, Siwarak; Sangaroon, Kiat; Inprasitha, Maitree
2014-01-01
The objectives of this research were to study and analyze the characteristics of computational thinking about the estimation of the students in mathematics classroom applying lesson study and open approach. Members of target group included 4th grade students of 2011 academic year of Choomchon Banchonnabot School. The Lesson plan used for data…
Estimating the ROI on an ERP for Naval aviation operations using market comparables
Jackson, David W.
2006-01-01
U.S. Navy aviation squadrons conduct a variety of flight operations in peace and wartime environments. At the heart of these operations is the flight scheduling that occurs to command and control the squadron's assets to ensure the actors and processes carry out the squadron's operations seamlessly and meet the squadron's mission requirements. This research and case study demonstrates how the Knowledge Value Added Methodology (KVA) and Business Process Reengineering (BPR) can be applied to t...
Hydroclimatic Characteristics of the 2012–2015 California Drought from an Operational Perspective
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Minxue He
2017-01-01
Full Text Available California experienced an extraordinary drought from 2012–2015 (which continues into 2016. This study, from an operational perspective, reviewed the development of this drought in a hydroclimatic framework and examined its characteristics at different temporal and spatial scales. Observed and reconstructed operational hydrologic indices and variables widely used in water resources planning and management at statewide and (hydrologic regional scales were employed for this purpose. Parsimonious metrics typically applied in drought assessment and management practices including the drought monitor category, percent of average, and rank were utilized to facilitate the analysis. The results indicated that the drought was characterized by record low snowpack (statewide four-year accumulated deficit: 280%-of-average, exceptionally low April-July runoff (220%-of-average deficit, and significantly below average reservoir storage (93%-of-average deficit. During the period from 2012–2015, in general, water year 2015 stood out as the driest single year; 2014–2015 was the driest two-year period; and 2013–2015 tended to be the driest three-year period. Contrary to prior studies stating that the 2012–2015 drought was unprecedented, this study illustrated that based on eight out of 28 variables, the 2012–2015 drought was not without precedent in the record period. Spatially, on average, the South Coast Region, the Central Coast Region, the Tulare Region, and the San Joaquin Region generally had the most severe drought conditions. Overall, these findings are highly meaningful for water managers in terms of making better informed adaptive management plans.
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V. V. Mikhailau
2016-01-01
Full Text Available Semi-natural tests for active pneumatic suspension of a 18-tonne tourist bus with the system of automatic body stabilization of the mobile machine and feed-back coupling according to kinematics parameter. The test have been executed in the cases when the bus is stocked with an automatic hydro-mechanical transmission in the process of speed picking up, gear-changing or road braking which is assigned by accidental road humps. A computer simulation of dynamic structures in combination with virtual devices and real objects (HIL – Hardware-in-the-Loop Simulation has been carried in the paper. Personal computers, software, programmed logic controller, frequency generator, solenoid-operated valve have been used for the investigation process. The paper proposes an unconventional method for improvement operational characteristics which is based on integrated control of a suspension and automatic hydro-mechanical transmission. A mathematical model includes systems of automatic transmission, suspension and module for generation of accidental road humps. The model has been considered as a basis for semi-natural laboratory bench with industrially-manufactured controller, other components of automatic systems and standard control organs. The most efficient method for body stabilization is control of the suspension according to the parameter of angular rate during vertical turn of an automobile’s center line with a turning point in the center of mass. The developed algorithm and stabilization system according to angular rate of body’s center line turning have made it possible to improve dynamics of the bus while making gear-changing and to reduce fuel consumption during starting-up and speed picking-up processes. During the braking process such system simultaneously decreases oscillation amplitude of some parameters more than two-fold.
Energy Technology Data Exchange (ETDEWEB)
Inoue, M.; Kiss, T.; Kuga, T.; Ishimaru, M.; Takeo, M.; Matsushita, T.; Iijima, Y.; Kakimoto, K.; Saitoh, T.; Awaji, S.; Watanabe, K.; Shiohara, Y
2003-10-15
E-J characteristics in a YBCO coated conductor at low temperature and very high magnetic field up to 27 T have been estimated using experimental E-J characteristics below 12 T along with a scaling analysis based on the percolation model. 1 mm thick YBCO films was deposited on a biaxially aligned Y{sub 2}O{sub 3}/YSZ/Hastelloy substrate fabricated by the IBAD technique. The critical current I{sub c} for the 1 cm wide tape was 85 A at 77 K in self-field. We measured E-J characteristics in perpendicular field up to 12 T using 100 {mu}m wide and 1 mm long bridge patterned in the tape. Statistic J{sub c} distribution and pinning properties were analyzed from the E-J characteristics. Using the pinning parameters determined by the scaling analysis, we can calculate the critical current properties as a function of temperature and magnetic field. E-J characteristics at low temperature and very high magnetic field up to 27 T were estimated analytically and compared with the experimental data. Estimated value of J{sub c} and n-value, and their error analysis were also discussed.
Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion
Energy Technology Data Exchange (ETDEWEB)
Choudhuri, Ahsan [Univ. Of Texas, El Paso, TX (United States)
2013-09-30
Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO_{2} from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H_{2} concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO_{2} and H_{2}O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient g_{F}) values for CH_{4}-O_{2}-CO_{2} flames. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH_{4}/21%O_{2}/79%N_{2} and CH_{4}/38%O_{2}/72%CO_{2} mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of
Sharp Weighted Estimates for a Class of n-dimensional Hardy-Steklov Operators
Institute of Scientific and Technical Information of China (English)
ZHENG QING-YU; SHI SHAO-GUANG; Ji You-qing
2011-01-01
In this paper,we study one class of n-dimensional Hardy-Steklov operators which has important applications in the technical analysis in equity markets.We establish their weighted boundedness and the corresponding operator norms on both Lp(Rn) and BMO(Rn).
Operating characteristics of a 0.87 kW-hr flywheel energy storage module
Loewenthal, S. H.; Scibbe, H. W.; Parker, R. D.; Zaretsky, E. V.
1985-01-01
Discussion is given of the design and loss characteristics of 0.87 kW-hr (peak) flywheel energy storage module suitable for aerospace and automotive applications. The maraging steel flywheel rotor, a 46-cm- (18-in-) diameter, 58-kg (128-lb) tapered disk, delivers 0.65 kW-hr of usable energy between operating speeds of 10,000 and 20,000 rpm. The rotor is supported by 20- and 25-mm bore diameter, deep-groove ball bearings, lubricated by a self-replenishing wick type lubrication system. To reduce aerodynamic losses, the rotor housing was evacuated to vacuum levels from 40 to 200 millitorr. Dynamic rotor instabilities uncovered during testing necessitated the use of an elastometric-bearing damper to limit shaft excursions. Spindown losses from bearing, seal, and aerodynamic drag at 50 millitorr typically ranged from 64 to 193 W at 10,000 and 20,000 rpm, respectively. Discharge efficiency of the flywheel system exceeded 96 percent at torque levels greater than 21 percent of rated torque.
Farsi, Davood; Pishbin, Elham; Abbasi, Saeed; Hafezimoghadam, Peyman; Fathi, Marzieh; Zare, Mohammad Amin
2013-04-01
The troponin I serum level is widely used in acute coronary syndrome patients for their classification. The qualitative assay is faster and more available than the quantitative assay. The objective was to determine the operating characteristics of a qualitative troponin I assay compared with a quantitative method. This is a prospective observational study and patients suspected to have acute coronary syndrome were enrolled. A rapid troponin I test and a quantitative assay were carried out for each patient on arrival and 6 h after admission. A total of 262 patients were enrolled. The degree of agreement between the second rapid qualitative and quantitative troponin I was excellent (κ=0.946; 95% confidence interval, 0.903-0.989). The sensitivity, specificity, negative predictive value, and positive predictive value of the rapid qualitative troponin I test were 92.6, 100, 96.8, and 100%, respectively. In conclusion, this study reveals an excellent agreement between quantitative and qualitative bedside assays 6 h after admission in a sample of Iranian patients in the emergency department.
Directory of Open Access Journals (Sweden)
Mimy Young
2013-12-01
Full Text Available Reported for the first time are receiver operating characteristic (ROC curves constructed to describe the performance of a sorbent-coated disk, planar solid phase microextraction (PSPME unit for non-contact sampling of a variety of volatiles. The PSPME is coupled to ion mobility spectrometers (IMSs for the detection of volatile chemical markers associated with the presence of smokeless powders, model systems of explosives containing diphenylamine (DPA, 2,4-dinitrotoluene (2,4-DNT and nitroglycerin (NG as the target analytes. The performance of the PSPME-IMS was compared with the widely accepted solid-phase microextraction (SPME, coupled to a GC-MS. A set of optimized sampling conditions for different volume containers (1–45 L with various sample amounts of explosives, were studied in replicates (n = 30 to determine the true positive rates (TPR and false positive detection rates (FPR for the different scenarios. These studies were obtained in order to construct the ROC curves for two IMS instruments (a bench-top and field-portable system and a bench top GC-MS system in low and high clutter environments. Both static and dynamic PSPME sampling were studied in which 10–500 mg quantities of smokeless powders were detected within 10 min of static sampling and 1 min of dynamic sampling.
Energy Technology Data Exchange (ETDEWEB)
Takahashi, Yasuyuki; Murase, Kenya [Osaka Medical Coll., Takatsuki (Japan). Graduate School; Higashino, Hiroshi; Sogabe, Ichiro; Sakamoto, Kana
2001-12-01
The quality of images reconstructed by means of the maximum likelihood-expectation maximization (ML-EM) and ordered subset (OS)-EM algorithms, was examined with parameters such as the number of iterations and subsets, then compared with the quality of images reconstructed by the filtered back projection method. Phantoms showing signals inside signals, which mimicked single-photon emission computed tomography (SPECT) images of cerebral blood flow and myocardial perfusion, and phantoms showing signals around the signals obtained by SPECT of bone and tumor were used for experiments. To determine signals for recognition, SPECT images in which the signals could be appropriately recognized with a combination of fewer iterations and subsets of different sizes and densities were evaluated by receiver operating characteristic (ROC) analysis. The results of ROC analysis were applied to myocardial phantom experiments and scintigraphy of myocardial perfusion. Taking the image processing time into consideration, good SPECT images were obtained by OS-EM at iteration No. 10 and subset 5. This study will be helpful for selection of parameters such as the number of iterations and subsets when using the ML-EM or OS-EM algorithms. (author)
Slotnick, Scott D; Jeye, Brittany M; Dodson, Chad S
2016-01-01
Is recollection a continuous/graded process or a threshold/all-or-none process? Receiver operating characteristic (ROC) analysis can answer this question as the continuous model and the threshold model predict curved and linear recollection ROCs, respectively. As memory for plurality, an item's previous singular or plural form, is assumed to rely on recollection, the nature of recollection can be investigated by evaluating plurality memory ROCs. The present study consisted of four experiments. During encoding, words (singular or plural) or objects (single/singular or duplicate/plural) were presented. During retrieval, old items with the same plurality or different plurality were presented. For each item, participants made a confidence rating ranging from "very sure old", which was correct for same plurality items, to "very sure new", which was correct for different plurality items. Each plurality memory ROC was the proportion of same versus different plurality items classified as "old" (i.e., hits versus false alarms). Chi-squared analysis revealed that all of the plurality memory ROCs were adequately fit by the continuous unequal variance model, whereas none of the ROCs were adequately fit by the two-high threshold model. These plurality memory ROC results indicate recollection is a continuous process, which complements previous source memory and associative memory ROC findings.
Directory of Open Access Journals (Sweden)
Heidi L. Weiss
2004-01-01
Full Text Available The role of biomarkers in disease prognosis continues to be an important investigation in many cancer studies. In order for these biomarkers to have practical application in clinical decision making regarding patient treatment and follow-up, it is common to dichotomize patients into those with low vs. high expression levels. In this study, receiver operating characteristic (ROC curves, area under the curve (AUC of the ROC, sensitivity, specificity, as well as likelihood ratios were calculated to determine levels of growth factor biomarkers that best differentiate lung cancer cases versus control subjects. Selected cut-off points for p185erbB-2 and EGFR membrane appear to have good discriminating power to differentiate control tissues versus uninvolved tissues from patients with lung cancer (AUC = 89% and 90%, respectively; while AUC increased to at least 90% for selected cut-off points for p185erbB-2 membrane, EGFR membrane, and FASE when comparing between control versus carcinoma tissues from lung cancer cases. Using data from control subjects compared to patients with lung cancer, we presented a simple and intuitive approach to determine dichotomized levels of biomarkers and validated the value of these biomarkers as surrogate endpoints for cancer outcome.
Linden, Ariel
2006-04-01
Diagnostic or predictive accuracy concerns are common in all phases of a disease management (DM) programme, and ultimately play an influential role in the assessment of programme effectiveness. Areas, such as the identification of diseased patients, predictive modelling of future health status and costs and risk stratification, are just a few of the domains in which assessment of accuracy is beneficial, if not critical. The most commonly used analytical model for this purpose is the standard 2 x 2 table method in which sensitivity and specificity are calculated. However, there are several limitations to this approach, including the reliance on a single defined criterion or cut-off for determining a true-positive result, use of non-standardized measurement instruments and sensitivity to outcome prevalence. This paper introduces the receiver operator characteristic (ROC) analysis as a more appropriate and useful technique for assessing diagnostic and predictive accuracy in DM. Its advantages include; testing accuracy across the entire range of scores and thereby not requiring a predetermined cut-off point, easily examined visual and statistical comparisons across tests or scores, and independence from outcome prevalence. Therefore the implementation of ROC as an evaluation tool should be strongly considered in the various phases of a DM programme.
Tanenbaum, Sandra J
2011-01-01
This research compares two types of consumer organizations in one state in order to explore the significance of organizational independence for internal structure/operations and external relationships. The first type, consumeroperated service organizations (COSOs), are independent and fully self-governing; the second are peer-support service organizations (PSSOs), which are part of larger non-consumer entities. Mail surveys were completed by COSO and PSSO directors of a geographically representative sample of organizations; telephone interviews were conducted with a sub-sample. Owing to small sample size, matched COSO-PSSO pairs were analyzed using non-parametric statistics. COSOs and PSSOs are similar in some ways, e.g., types of services provided, but significantly different on internal variables, such as budget size, and external variables, such as number of relationships with community groups. Organizational independence appears to be a significant characteristic for consumer service organizations and should be encouraged by funders and among participants. Funders might establish administrative and/or programmatic measures to support consumer organizations that are independent or moving toward independence; their participants would also benefit from the provision, by authorities or advocates, of materials to guide organizations toward, for example, 501(c)3 status.
Design of a receiver operating characteristic (ROC) study of 10:1 lossy image compression
Collins, Cary A.; Lane, David; Frank, Mark S.; Hardy, Michael E.; Haynor, David R.; Smith, Donald V.; Parker, James E.; Bender, Gregory N.; Kim, Yongmin
1994-04-01
The digital archiving system at Madigan Army Medical Center (MAMC) uses a 10:1 lossy data compression algorithm for most forms of computed radiography. A systematic study on the potential effect of lossy image compression on patient care has been initiated with a series of studies focused on specific diagnostic tasks. The studies are based upon the receiver operating characteristic (ROC) method of analysis for diagnostic systems. The null hypothesis is that observer performance with approximately 10:1 compressed and decompressed images is not different from using original, uncompressed images for detecting subtle pathologic findings seen on computed radiographs of bone, chest, or abdomen, when viewed on a high-resolution monitor. Our design involves collecting cases from eight pathologic categories. Truth is determined by committee using confirmatory studies performed during routine clinical practice whenever possible. Software has been developed to aid in case collection and to allow reading of the cases for the study using stand-alone Siemens Litebox workstations. Data analysis uses two methods, ROC analysis and free-response ROC (FROC) methods. This study will be one of the largest ROC/FROC studies of its kind and could benefit clinical radiology practice using PACS technology. The study design and results from a pilot FROC study are presented.
The effect of maximum open height on operating characteristics of polymer injected pump poppet valve
Zhang, S. C.; Chen, X. D.; Deng, H. Y.
2012-11-01
Reciprocating polymer injected pump is the key injection equipment of tertiary oil recovery, the poppet valve in it exists the problem of large vibration noise, low efficiency and short life when transportation high viscosity medium. So the CFD technique is adopted to simulate and analyze the inner flow fields of fluid end poppet valve. According to the practical structure of the poppet valve, a simplified 2D axis-symmetry geometry model of the flow field is established. Combined with pump speed, plunger stroke and plunger diameter, given the boundary condition of the inlet valve, then the numerical simulation of flow field under six different maximum open heights is done depending on software Fluent. The relationship between open height to valve gap flow velocity, hydraulic loss and lag angle is obtained. The results indicate that, with the increase of open height, the valve gap flow velocity decreases, inlet outlet pressure differential decreases and hydraulic loss decreases. But the lag angle is continuously increasing with the increase of maximum open height, the valve has a good work performance when the open height is 1, 1.5, 2, 2.5, 3mm, but when it reaches 3.5mm, the valve performance becomes poor. The study can offer certain reference to understand operating characteristics of poppet valve, help to reduce the hydraulic losses and raise volume efficiency of the pump.
Directory of Open Access Journals (Sweden)
Zhenke Luo
2014-12-01
Full Text Available Mixed traffic flow composed of autos and non-autos widely exists in developing countries and areas. To investigate the operational characteristics of the mixed traffic flow consisting of vehicles in different types (large vehicles, cas, and bicycles, we develop a cellular automaton model to replicate the travel behaviors on a bi-directional road segment with respect to the physical and mechanic ftures of différent vehicle types. By implementing the eesential parameters calibrated through the field data collection, a numerical study is carried out considering the variation in volume, density, and velocity with different compositions of mixed traffic flows. The primary findings include: the average velocity of traffic flow and total volume decrease 60% and 30% after incorporating 10% bicycles, respectively; the phenomenon of double-summit in terms of the total volume appears when the proportion of bicycle is beyond 60%; the maximal total volume starts to recover when the proportion of bicycle is higher than 10 %.
Characteristic parameters and operational curves of γ-Al2O3 nanofiltration membranes
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
The γ-Al2O3 nanofiltration membranes were manufactured by the sol-gel technique. The result of N2 adsorption and desorption test indicates that the characteristic parameters of the membranes: BJH desorption average pore diameter, BJH desorption cumulative volume of pores and BET surface area are about 3.9 nm, 0.33 cm3/g and 245 m2/g respectively, and the pore size distribution is very narrow. The operational curves of γ-Al2O3 nanofiltration membranes of the Ca2+ retention rate vs the trans-membrane pressure, feed concentration of solution treated and pH of solution treated were studied for the first time. It is found that the retention rate for Ca2+ increases with the transmembrane pressure increasing and decreases with the feed concentration of CaCl2 solution increasing. The retention of Ca2+ is very much dependent on the pH of the solution. Minimal Ca2+ retention rate is found at the isoelectric point (pH = 7.5).
Parrett, Charles; Johnson, D.R.; Hull, J.A.
1989-01-01
Estimates of streamflow characteristics (monthly mean flow that is exceeded 90, 80, 50, and 20 percent of the time for all years of record and mean monthly flow) were made and are presented in tabular form for 312 sites in the Missouri River basin in Montana. Short-term gaged records were extended to the base period of water years 1937-86, and were used to estimate monthly streamflow characteristics at 100 sites. Data from 47 gaged sites were used in regression analysis relating the streamflow characteristics to basin characteristics and to active-channel width. The basin-characteristics equations, with standard errors of 35% to 97%, were used to estimate streamflow characteristics at 179 ungaged sites. The channel-width equations, with standard errors of 36% to 103%, were used to estimate characteristics at 138 ungaged sites. Streamflow measurements were correlated with concurrent streamflows at nearby gaged sites to estimate streamflow characteristics at 139 ungaged sites. In a test using 20 pairs of gages, the standard errors ranged from 31% to 111%. At 139 ungaged sites, the estimates from two or more of the methods were weighted and combined in accordance with the variance of individual methods. When estimates from three methods were combined the standard errors ranged from 24% to 63 %. A drainage-area-ratio adjustment method was used to estimate monthly streamflow characteristics at seven ungaged sites. The reliability of the drainage-area-ratio adjustment method was estimated to be about equal to that of the basin-characteristics method. The estimate were checked for reliability. Estimates of monthly streamflow characteristics from gaged records were considered to be most reliable, and estimates at sites with actual flow record from 1937-86 were considered to be completely reliable (zero error). Weighted-average estimates were considered to be the most reliable estimates made at ungaged sites. (USGS)
Outer measures and weak type estimates of Hardy-Littlewood maximal operators
Directory of Open Access Journals (Sweden)
Terasawa Yutaka
2006-01-01
Full Text Available We will introduce the times modified centered and uncentered Hardy-Littlewood maximal operators on nonhomogeneous spaces for . We will prove that the times modified centered Hardy-Littlewood maximal operator is weak type bounded with constant when if the Radon measure of the space has "continuity" in some sense. In the proof, we will use the outer measure associated with the Radon measure. We will also prove other results of Hardy-Littlewood maximal operators on homogeneous spaces and on the real line by using outer measures.
Estimating the number of eigenvalues of linear operators on Banach spaces
Demuth, Michael; Hanauska, Franz; Hansmann, Marcel; Katriel, Guy
2014-01-01
Let $L_0$ be a bounded operator on a Banach space, and consider a perturbation $L=L_0+K$, where $K$ is compact. This work is concerned with obtaining bounds on the number of eigenvalues of $L$ in subsets of the complement of the essential spectrum of $L_0$, in terms of the approximation numbers of the perturbing operator $K$. Our results can be considered as wide generalizations of classical results on the distribution of eigenvalues of compact operators, which correspond to the case $L_0=0$....
Operational characteristics analysis of a 8 mH class HTS DC reactor for an LCC type HVDC system
Energy Technology Data Exchange (ETDEWEB)
Kim, S. K.; Go, B. S.; Dinh, M. C.; Park, M.; Yu, I. K. [Changwon National University, Changwon (Korea, Republic of); Kim, J. H. [Daejeon University, Daejeon (Korea, Republic of)
2015-03-15
Many kinds of high temperature superconducting (HTS) devices are being developed due to its several advantages. In particular, the advantages of HTS devices are maximized under the DC condition. A line commutated converter (LCC) type high voltage direct current (HVDC) transmission system requires large capacity of DC reactors to protect the converters from faults. However, conventional DC reactor made of copper causes a lot of electrical losses. Thus, it is being attempted to apply the HTS DC reactor to an HVDC transmission system. The authors have developed a 8 mH class HTS DC reactor and a model-sized LCC type HVDC system. The HTS DC reactor was operated to analyze its operational characteristics in connection with the HVDC system. The voltage at both ends of the HTS DC reactor was measured to investigate the stability of the reactor. The voltages and currents at the AC and DC side of the system were measured to confirm the influence of the HTS DC reactor on the system. Two 5 mH copper DC reactors were connected to the HVDC system and investigated to compare the operational characteristics. In this paper, the operational characteristics of the HVDC system with the HTS DC reactor according to firing angle are described. The voltage and current characteristics of the system according to the types of DC reactors and harmonic characteristics are analyzed. Through the results, the applicability of an HTS DC reactor in an HVDC system is confirmed.
Energy Technology Data Exchange (ETDEWEB)
Lee, Gi Hwa [Seoul National Univ., Seoul (Korea, Republic of)
1997-11-15
The purpose of the present study is to develop predictive equations from simulated motions which are adequate for the Korean Peninsula and analyze and utilize the computer programs for the probabilistic estimation of design earthquakes. In part I of the report, computer programs for the probabilistic estimation of design earthquake are analyzed and applied to the seismic hazard characterizations in the Korean Peninsula. In part II of the report, available instrumental earthquake records are analyzed to estimate earthquake source characteristics and medium properties, which are incorporated into simulation process. And earthquake records are simulated by using the estimated parameters. Finally, predictive equations constructed from the simulation are given in terms of magnitude and hypocentral distances.
Rosso, Sonia M; Donker Kaat, Laura; Baks, Timo; Joosse, Marijke; de Koning, Inge; Pijnenburg, Yolande; de Jong, Daniëlle; Dooijes, Dennis; Kamphorst, Wouter; Ravid, Rivka; Niermeijer, Martinus F; Verheij, Frans; Kremer, H P; Scheltens, Philip; van Duijn, Cornelia M; Heutink, Peter; van Swieten, John C
Since 1994, a population-based study of frontotemporal dementia (FTD) in The Netherlands has aimed to ascertain all patients with FTD, and first prevalence estimates based on 74 patients were reported in 1998. Here, we present new prevalence estimates after expansion of our FTD population to 245
S.M. Rosso (Sonia); L. Donker Kaat (Laura); T. Baks (Timo); M. Joosse (Marijke); I. de Koning (Inge); Y. Pijnenburg (Yolande); D. de Jong (Danielle); D. Dooijes (Dennis); W. Kamphorst (Wouter); R. Ravid (Rivka); M.F. Niermeijer (Martinus); F. Verheij (Fop); H.P. Kremer; P. Scheltens (Philip); C.M. van Duijn (Cock); P. Heutink (Peter); J.C. van Swieten (John)
2003-01-01
textabstractSince 1994, a population-based study of frontotemporal dementia (FTD) in The Netherlands has aimed to ascertain all patients with FTD, and first prevalence estimates based on 74 patients were reported in 1998. Here, we present new prevalence estimates after expansion of our FTD populatio
Estimation of intra-operative brain shift using a tracked laser range scanner.
Ding, Siyi; Miga, Michael I; Thompson, Reid C; Dumpuri, Prashanth; Cao, Aize; Dawant, Benoit M
2007-01-01
Intra-operative brain shift limits the usefulness of image-guided neurosurgery systems (IGNS), which are based on pre-operative images. Methods that are being developed to address this problem need intra-operative measurements as input. In this work, we present an intra-operative surface shift measurement technique that relies on a tracked 3D laser range scanner. This scanner acquires both 3D range data and 2D images, which are co-registered. We compare two methods to derive displacements at every point in the field of view. The first one relies on the registration of the 2D images; the second relies on the direct 3D registration of the 3D range data. Our results, based on five data sets, show that the 2D method is preferable.
Indian Academy of Sciences (India)
M El Hamma; R Daher
2014-05-01
Using a generalized spherical mean operator, we define generalized modulus of smoothness in the space $L^2_k(\\mathbb{R}^d)$. Based on the Dunkl operator we define Sobolev-type space and -functionals. The main result of the paper is the proof of the equivalence theorem for a -functional and a modulus of smoothness for the Dunkl transform on $\\mathbb{R}^d$.
Hansmann, Marcel
2015-01-01
In the first part of this paper we provide a self-contained introduction to (regularized) perturbation determinants for operators in Banach spaces. In the second part, we use these determinants to derive new bounds on the discrete eigenvalues of compactly perturbed operators, broadly extending some recent results by Demuth et al. In addition, we also establish new bounds on the discrete eigenvalues of generators of $C_0$-semigroups.
Fichtner, Thomas; Vanzella de Melo, Julio Augusto; Stefan, Catalin
2016-04-01
The main focus during operation of managed aquifer recharge (MAR) is on clogging processes, specifically on the changes of infiltration capacities and degradation of infiltrated organic substances including vadose zone oxygen dynamics. Lab scale experiments are one opportunity to understand and characterize these processes under different drying and wetting cycles and infiltration rates. However, the multitude of assumptions and scale-related limitations of downscale investigations often lead to over- or underestimations, rendering their results useless when translated to field-like conditions. Therefore, the specific objective of this investigation is to compare the results obtained from two different experimental set-ups with different scales: a 3D, rectangular shaped, stainless steel lysimeter (1.5 x 1.0 x 1.0 m) with an infiltration basin installed in the centre of its surface and a 1D soil column (1m, ᴓ 0.15 m) with the infiltration over the complete column surface. The study focuses on the influence of the experimental setup conditions on the soil clogging, water flow pattern, oxygen dynamics and degradation of organic substances. The results should allow making statements about the suitability of these lab experiments for the investigation of processes taking place in the unsaturated soil zone during operation of MAR. Both experimental units were packed with the same soil and equipped with tensiometers, TDR-probes, oxygen probes and suction cups in two depths for the estimation of spatial and temporal distribution of soil moisture, oxygen and infiltrated substances. The lysimeter and the column were placed inside of a fully automatic climate tent, which facilitates the exact control of air temperature and humidity. The first results confirm that both infiltration units are suitable to simulate the clogging and the oxidation of easily degradable organic substances. However, the velocity of water transport is higher in the column compared with the lysimeter
Energy Technology Data Exchange (ETDEWEB)
Baskakov, A G [Voronezh State University (Russian Federation)
2015-08-31
By applying Lyapunov's equation, the method of similar operators, and the methods of harmonic analysis, we obtain estimates for the parameters of exponential dichotomy and for the Green's function constructed for a hyperbolic operator semigroup and a hyperbolic linear relation. Estimates are obtained using quantities which are determined by the resolvent of the infinitesimal operator of the operator semigroup and of the linear relation. Bibliography: 51 titles.
DEFF Research Database (Denmark)
Petersen, Lars Norbert; Jørgensen, John Bagterp; Rawlings, James B.
2015-01-01
In this paper, we develop an economically optimizing Nonlinear Model Predictive Controller (E-NMPC) for a complete spray drying plant with multiple stages. In the E-NMPC the initial state is estimated by an extended Kalman Filter (EKF) with noise covariances estimated by an autocovariance least...... squares method (ALS). We present a model for the spray drying plant and use this model for simulation as well as for prediction in the E-NMPC. The open-loop optimal control problem in the E-NMPC is solved using the single-shooting method combined with a quasi-Newton Sequential Quadratic programming (SQP...
1986-01-01
TUPS) SAMPLE VOLUME 50rril NUMBER OF AVERAGE BIOMA ~SS CELLS/L CELL SIZE ESTIMATE DIATOMS m 3 xl ~ m 3 x162 Bacteriastrum delicatulurr Chaetoceros...DATE 5/09/85 :long 70 27.64W TIME 1209 GMT VOLUME FILTERED 0.5L DEPTH 2m SAMPLE VOLUME 50mI NUMBER OF AVERAGE BIOMA ~SS CELLS/L CELL SIZE ESTIMATE...Directorate PROGRAM PROJECT TASK WORK UNIT NSTL, MS 39529-5004 ELEMENT NO, NO. NO. No. 61153NI ll.TITtAteaWSc@CaaCA"OdnhOcear. rona Areas hytoplankton
Hanford, K J; Van Vleck, L D; Snowder, G D
2003-03-01
Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight, and wool traits were estimated using REML with animal models for Targhee sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station, Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated with the parameters estimated from the single-trait and bivariate analyses were compared across years of birth with respect to genetic trends. The numbers of observations were 38,625 for litter size at birth and litter size at weaning, 33,994 for birth weight, 32,715 for weaning weight, 36,807 for fleece weight and fleece grade, and 3,341 for staple length. Direct heritability estimates from single-trait analyses were 0.10 for litter size at birth, 0.07 for litter size at weaning, 0.25 for birth weight, 0.22 for weaning weight, 0.54 for fleece weight, 0.41 for fleece grade, and 0.65 for staple length. Estimate of direct genetic correlation between litter size at birth and weaning was 0.77 and between birth and weaning weights was 0.52. The estimate of genetic correlation between fleece weight and staple length was positive (0.54), but was negative between fleece weight and fleece grade (-0.47) and between staple length and fleece grade (-0.69). Estimates of genetic correlations were near zero between birth weight and litter size traits and small and positive between weaning weight and litter size traits. Fleece weight was slightly and negatively correlated with both litter size traits. Fleece grade was slightly and positively correlated with both litter size traits. Estimates of correlations between staple length and litter size at birth (-0.14) and litter size at weaning (0.05) were small. Estimates of correlations between weight traits and fleece weight were positive and low to moderate. Estimates of correlations between weight traits and fleece grade were negative and small, whereas estimates between weight traits and staple length were
Brewick, P. T.; Smyth, A. W.
2013-12-01
Simulations of estimating the modal damping on a bridge from hour-long records of traffic loading were conducted by combining physics-based finite element modeling and signal processing. The finite element method was used to model a bridge consisting of a series of stringer beams resting atop a larger girder. The traffic loads were separated into trains and cars, with the trains modeled as partially distributed moving masses traveling along the girder and the cars modeled as point loads moving along the stringers. From the acceleration time histories, different operational modal analysis (OMA) techniques were used to find estimates for the modal coefficients of damping. The results demonstrated that a quasi-periodic component in the traffic loading introduces significant error to the damping estimates. This error could be observed in the distortion of the peaks for the power spectral densities (PSD) generated from the responses to the traffic simulations. The main OMA technique explored for the damping estimates was Enhanced Frequency Domain Decomposition (EFDD), but it could not compensate or correct for any alterations to the PSD. Other techniques such as the Stochastic Subspace Identification (SSID) method and curve-fitting frequency domain analysis were evaluated, but they produced comparable damping ratio estimates to EFDD and similarly resulted in large errors for the distorted modes. The influence of quasi-periodic loads was perceptible, which means that for certain cases, the nature of traffic loads may result in damping estimates that are considerably inaccurate no matter what OMA technique is chosen.
Directory of Open Access Journals (Sweden)
Ana-Maria Budai
2015-09-01
Full Text Available In this paper are presented a graphic - analytic method that can be used to estimate the fatigue lifetime duration for an operating mechanism lever pin to a Kaplan turbine. The presented calculus algorithm is adapted from the one used by Fuji Electric to made strength calculus in order to refurbish a Romanian hydropower plant, equipped with a Kaplan turbine. The graphic part includes a 3D fatigue diagram for rotating bending stress designed by Fuji Electric specialists.
Estimation of Energy Consumption in COREX Process Using a Modified Rist Operating Diagram
Institute of Scientific and Technical Information of China (English)
Wen-long ZHAN; Keng WU; Zhi-jun HE; Qi-hang LIU; Xiao-juan WU
2015-01-01
Fuel consumption in the COREX-3000 process run in Baosteel is currently higher than the design index. Therefore,mass and heat balance equations for the COREX process were established using the basic principles in-cluded in the Rist operating diagram for blast furnace (BF)as a reference.Thermodynamic calculations were then used to modify the Rist operating diagram so that it was suitable for the COREX process.The modified Rist operating dia-gram was then applied for the evaluation of metallization rate (MR)and fuel structure to reduce the energy consump-tion in the COREX process.The modified Rist operating diagram for the shaft furnace (SF)provided a nearly ideal value for the restriction point W when the metallization rate was increased,while the point P on the operating line for the melter gasifier (MG)moved upward due to reduction in the heat required in hearth.The feasibility of reduc-ing the energy consumption during the COREX process by changing the fuel structure was also demonstrated.
Operational space synchronization of two robot manipulators through a virtual velocity estimate
Directory of Open Access Journals (Sweden)
Erik Kyrkjebø
2008-04-01
Full Text Available Two robot manipulators are synchronized in a leader-follower scheme where only joint position measurements of the leader are available. A virtual manipulator is designed to provide a velocity estimate of the unknown leader velocity to the control law of the follower. The closed-loop errors are shown to be uniformly globally practically asymptotically stable.
A dispersive estimate for the Schr\\"odinger operator in star-shaped networks
Mehmeti, Felix Ali; Nicaise, Serge
2012-01-01
We prove time decay $L^1 ({\\cal R}) \\rightarrow L^\\infty ({\\cal R}),$ where ${\\cal R}$ is an infinite star-shaped network, estimates for the Schr\\"odinger group $e^{it(- \\frac{d^2}{dx^2} + V)}$ for real-valued potentials $V$ satisfy some regularity and decay assumptions.
Hanford, K J; Van Vleck, L D; Snowder, G D
2002-12-01
Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and bivariate analyses were compared with respect to genetic trends. Number of observations were 31,401 for litter size at birth and litter size at weaning, 24,741 for birth weight, 23,903 for weaning weight, 29,572 for fleece weight and fleece grade, and 2,449 for staple length. Direct heritability estimates from single-trait analyses were 0.09 for litter size at birth, 0.06 for litter size at weaning, 0.27 for birth weight, 0.16 for weaning weight, 0.53 for fleece weight, 0.41 for fleece grade, and 0.55 for staple length. Estimate of direct genetic correlation between littersize at birth and weaning was 0.84 and between birth and weaning weights was 0.56. Estimate of genetic correlation between fleece weight and staple length was positive (0.55) but negative between fleece weight and fleece grade (-0.47) and between staple length and fleece grade (-0.70). Estimates of genetic correlations were positive but small between birth weight and litter size traits and moderate and positive between weaning weight and litter size traits. Fleece weight was lowly and negatively correlated with both litter size traits. Fleece grade was lowly and positively correlated with both litter size traits, while staple length was lowly and negatively correlated with the litter size traits. Estimates of correlations between weight traits and fleece weight were positive and low to moderate. Estimates of correlations between weight traits and fleece grade were negative and small. Estimates of correlations between staple length and birth weight (0.05) and weaning weight were small (-0.04). Estimated
DEFF Research Database (Denmark)
Skafte, Anders; Aenlle, Manuel L.; Brincker, Rune
2016-01-01
measuring the in-plane deformation. This paper proposes a method in which the displacement mode shapes and responses can be predicted using only strain measurements. The method relies on the newly discovered principle of local correspondence, which states that each experimental mode can be expressed....... The method is validated with experimental tests on a scaled model of a two-span bridge installed with strain gauges. Random load was applied to simulate a civil structure under operating condition, and strain mode shapes were identified using operational modal analysis....
DEFF Research Database (Denmark)
Savović, J; Jones, He; Altman, Dg
2012-01-01
The design of randomised controlled trials (RCTs) should incorporate characteristics (such as concealment of randomised allocation and blinding of participants and personnel) that avoid biases resulting from lack of comparability of the intervention and control groups. Empirical evidence suggests...
Riggio, V.; Pesce, L.L.; Morreale, S.; Portolano, B.
2013-01-01
Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would optimal
Riggio, V.; Pesce, L.L.; Morreale, S.; Portolano, B.
2013-01-01
Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would
DEFF Research Database (Denmark)
Ozenne, Brice; Subtil, Fabien; Maucort-Boulch, Delphine
2015-01-01
OBJECTIVES: Compare the area under the receiver operating characteristic curve (AUC) vs. the area under the precision-recall curve (AUPRC) in summarizing the performance of a diagnostic biomarker according to the disease prevalence. STUDY DESIGN AND SETTING: A simulation study was performed...
Laracy, Seth D.; Hojnoski, Robin L.; Dever, Bridget V.
2016-01-01
Receiver operating characteristic curve (ROC) analysis was used to investigate the ability of early numeracy curriculum-based measures (EN-CBM) administered in preschool to predict performance below the 25th and 40th percentiles on a quantity discrimination measure in kindergarten. Areas under the curve derived from a sample of 279 students ranged…
Blinov, N N; Zelikman, M I; Kruchinin, S A
2007-01-01
The results of testing of hardware and software for monitoring parameters (mean number of CT units, noise, field uniformity, high-contrast spatial resolution, layer width, dose) and characteristics (modulation transfer function) of X-ray computer tomographs are presented. The developed hardware and software are used to monitor the stability of X-ray computer tomograph parameters under operation conditions.
2006-01-01
METHOD 2.1 Building the model Using existing task analyses of navy sonar systems (Matthews, Greenley and Webb, 1991) and with the assistance of...Critical Operator Tasks. DRDC Toronto Report # CR-2003-131 Matthews, M.L., Greenley , M. and Webb, R.D.G (1991). Presentation of Information from Towed
Operational Implementation of Sea Ice Concentration Estimates from the AMSR2 Sensor
Meier, Walter N.; Stewart, J. Scott; Liu, Yinghui; Key, Jeffrey; Miller, Jeffrey A.
2017-01-01
An operation implementation of a passive microwave sea ice concentration algorithm to support NOAA's operational mission is presented. The NASA team 2 algorithm, previously developed for the NASA advanced microwave scanning radiometer for the Earth observing system (AMSR-E) product suite, is adapted for operational use with the JAXA AMSR2 sensor through several enhancements. First, the algorithm is modified to process individual swaths and provide concentration from the most recent swaths instead of a 24-hour average. A latency (time since observation) field and a 24-hour concentration range (maximum-minimum) are included to provide indications of data timeliness and variability. Concentration from the Bootstrap algorithm is a secondary field to provide complementary sea ice information. A quality flag is implemented to provide information on interpolation, filtering, and other quality control steps. The AMSR2 concentration fields are compared with a different AMSR2 passive microwave product, and then validated via comparison with sea ice concentration from the Suomi visible and infrared imaging radiometer suite. This validation indicates the AMSR2 concentrations have a bias of 3.9% and an RMSE of 11.0% in the Arctic, and a bias of 4.45% and RMSE of 8.8% in the Antarctic. In most cases, the NOAA operational requirements for accuracy are met. However, in low-concentration regimes, such as during melt and near the ice edge, errors are higher because of the limitations of passive microwave sensors and the algorithm retrieval.
C. Ogbonna Emerole; K. Charles Osondu; O. Chidozie Anyiro; O. Alexan Orji
2013-01-01
This study on trade enhancement Characteristics of sweet (dessert) banana fruit and estimation of transaction costs was conducted in Okigwe Metropolis of Imo State, Nigeria. Stratified random sampling technique was adopted in selecting 80 respondents comprising 40 dessert banana traders (panelists) and 40 dessert banana consumers. Monthly trade data was collected from the respondents using pretested semi-structured questionnaire during dry season (November-April) and rain season (May-October)...
Tanohata, Naoki; Seki, Hirokazu
This paper describes a novel drive control scheme of electric power assisted wheelchairs based on neural network learning of human wheelchair operation characteristics. “Electric power assisted wheelchair” which enhances the drive force of the operator by employing electric motors is expected to be widely used as a mobility support system for elderly and disabled people. However, some handicapped people with paralysis of the muscles of one side of the body cannot maneuver the wheelchair as desired because of the difference in the right and left input force. Therefore, this study proposes a neural network learning system of such human wheelchair operation characteristics and a drive control scheme with variable distribution and assistance ratios. Some driving experiments will be performed to confirm the effectiveness of the proposed control system.
Optimal heat kernel estimates for Schroedinger operators with magnetic fields in two dimensions
Energy Technology Data Exchange (ETDEWEB)
Loss, M. [Georgia Inst. of Tech., Atlanta (United States). School of Mathematics; Thaller, B. [Institut fuer Mathematik, Universitaet Graz, A-8010 Graz (Austria)
1997-06-01
Sharp smoothing estimates are proven for magnetic Schroedinger semigroups in two dimensions under the assumption that the magnetic field is bounded below by some positive constant B{sub 0}. As a consequence the L{sup {infinity}} norm of the associated integral kernel is bounded by the L{sup {infinity}} norm of the Mehler kernel of the Schroedinger semigroup with the constant magnetic field B{sub 0}. (orig.)
APPROACH TO ESTIMATION OF THE MARKET VOLUME FOR COMPANIES OPERATING IN THE B2B SEGMENT
Directory of Open Access Journals (Sweden)
Alla B. Kochergina
2014-01-01
Full Text Available This article shows the approach for estimating amount of alive enterprises inRussia. The main focus is on the way of detecting an business-active companiesusing the formal signs. The author proposes some signs for indicating of thebusiness activity. The developed model allows to clarify the amount of active enterprises in stages using those signs. The author provides the approach how to applythis model for different markets.
A Monocular SLAM Method to Estimate Relative Pose During Satellite Proximity Operations
2015-03-26
HOMER video sequence in Figure 17) provides the relative rotation and translation required from the perspective of the camera for successful...shows the SLAM results, with the camera models representing the relative pose estimates of the camera on the arm. Figure 40 shows another perspective of...ensures initialization is performed with adequate relative motion. If no additional perspective information is obtained in an initialization attempt, a
Estimating for Sediment Yield During Storm Based on Soil and Watershed Geomorphology Characteristics
Lee, K.; Yang, C.
2008-05-01
Concentrated rainfall usually results in serious soil erosion on steep hillslopes. Since the itinerary of the eroded sediment is complicated and measure for temporal sediment concentration is a laborious work, estimating for watershed erosion during storm is considered as difficulty in practice. In this study, a simple method for estimating sediment yield during storm was derived. By using soil data and watershed geomorphologic information, analytical solutions for sediment travel times and delivery ratios for different orders of overland areas and channels were derived to form an instantaneous unit sedimentgraph. Consequently, sediment yield during storm can be estimated by convoluting the rainfall intensities with the proposed instantaneous unit sedimentgraph. In this study, the proposed model has been verified using the data from Goodwin Experimental Watershed located in Mississippi of the United States. A digital elevation model was adopted to obtain the watershed geomorphologic factors for subsequent runoff routing and sediment concentration estimations. The simulated and the measured sediment yields were in good agreement for the test storms. It is therefore promising for the proposed model to be used for sediment yield estimation in gauged and ungauged watersheds for water resources design work.
Main components and characteristics of landslide early warning systems operational worldwide
Piciullo, Luca; Cepeda, José
2017-04-01
During the last decades the number of victims and economic losses due to natural hazards are dramatically increased worldwide. The reason can be mainly ascribed to climate changes and urbanization in areas exposed at high level of risk. Among the many mitigation measures available for reducing the risk to life related to natural hazards, early warning systems certainly constitute a significant cost-effective option available to the authorities in charge of risk management and governance. The aim is to help and protect populations exposed to natural hazards, reducing fatalities when major events occur. Landslide is one of the natural hazards addressed by early warning systems. Landslide early warning systems (LEWSs) are mainly composed by the following four components: set-up, correlation laws, decisional algorithm and warning management. Within this framework, the set-up includes all the preliminary actions and choices necessary for designing a LEWS, such as: the area covered by the system, the types of landslides and the monitoring instruments. The monitoring phase provides a series of important information on different variables, considered as triggering factors for landslides, in order to define correlation laws and thresholds. Then, a decisional algorithm is necessary for defining the: number of warning levels to be employed in the system, decision making procedures, and everything else system managers may need for issuing warnings in different warning zones. Finally the warning management is composed by: monitoring and warning strategy; communication strategy; emergency plan and, everything connected to the social sphere. Among LEWSs operational worldwide, two categories can be defined as a function of the scale of analysis: "local" and "territorial" systems. The scale of analysis influences several actions and aspects connected to the design and employment of the system, such as: the actors involved, the monitoring systems, type of landslide phenomena
Estimation Methods for Determination of Drag Characteristics of Fly-by-Wire Aircraft
Directory of Open Access Journals (Sweden)
G. Girija
2001-01-01
Full Text Available "In this paper, several parameter/state estimation approaches for the determination of drag polars from flight data are described and evaluated for a fly-by-wire (FBW aircraft. Both model-based approaches (MBAs and non-model-based approaches (NMBAs are considered. Dynamic response data from roller coaster and wind- up-turn manoeuvres are generated in a FBW aircraft flight simulator at different flight conditions and the typical performance results are presented. A novel approach to estimate the drag polar has been evaluated. It has been found that the NMBAs perform better than the MBAs. Classically, the MBAs have been used for the determination of drag polars. The merits of an NMBA are that it does not require specification of the detailed model of the aerodynamic coefficients and it can be suitably used for online estimation of drag polars from the flight data of aerospace vehicles
An estimation of load characteristics of an ultrasonic motor by measuring transient responses.
Nakamura, K; Kurosawa, M; Kurebayashi, H; Ueha, S
1991-01-01
To measure the characteristics of ultrasonic motors, such as the maximum torque, torque-speed relationship and the frictional coefficient at the contact surface, a method in which the torque is calculated from the transient responses is proposed. The rise curve that is the transitional change in the rotor speed soon after turning on the motor gives the load characteristics, while the fall curve that is the decay of the rotor speed after turning off the motor yields the frictional coefficient of the contact surface. This method requires only a short time (the transient time of the motor) to complete the measurement. The relations between the transient responses, the load characteristics and the frictional force are analyzed, and the method is applied to a hybrid transducer type rotary motor and a traveling wave type linear motor.
Chu, Ya; Liu, Songyu; Wang, Fei; Cai, Guojun; Bian, Hanliang
2017-05-01
Under the process of urbanization in China, more and more attention has been paid to the reuse of heavy metal-contaminated sites. The shear characteristics of heavy metal-contaminated soils are investigated by electrical detection in this paper. Three metal ions (Zn(2+), Cd(2+), and Pb(2+)) were used, the metal concentrations of which are 50, 166.67, 500, 1666.67, and 5000 mg/kg, respectively. Direct shear tests were used to investigate the influence of heavy metal ions on the shear characters of soil samples. It is found that with the addition of heavy metal ions, the shear strength, cohesion, and friction angle of contaminated soils are higher than the control samples. The higher concentration of heavy metal ions penetrated in soils, the higher these engineering characteristics of contaminated soils observed. In addition, an electrical resistivity detection machine is used to evaluate the shear characteristics of contaminated soils. The electrical resistivity test results show that there is a decreasing tendency of resistivity with the increase of heavy metal ion concentrations in soils. Compared with the electrical resistivity and the shear characteristics of metal-contaminated soils, it is found that, under fixed compactness and saturation, shear strength of metal-contaminated soils decreased with the increase of resistivity. A basic linear relationship between C/log(N + 10) and resistivity can be observed, and there is a basic linear relationship between φ/log(N + 10) and resistivity. Besides, a comparison of the measured and predicted shear characteristics shows a high accuracy, indicating that the resistivity can be used to evaluate the shear characteristics of heavy metal contaminated soils.
Energy Technology Data Exchange (ETDEWEB)
Cuerva, A.
1996-12-01
The main need of the EWTS-II Sub-project IV group is to have a suitable data-base which allows it to reach proper conclusions on the characteristics of power performance of wind turbines in complex terrain. With this aim, this document presents an analysis on the power output of the MADE AE-30 Wind turbine operating at Tarifa (also data from flat terrain are enclosed as a reference). An application of the bin method and AEP estimation for energy production method, in the two last issues a directional analysis and an study for two different turbulence intensity ranges are enclosed. Finally the Stepwise multirregression method is applied on the measurements to identify the stored parameters that have influence on the power output. A brief description of multi stall effect is enclosed. (Author)
Yuan, Xiangjuan; Gao, Dawen; Liang, Hong
2012-06-01
Aerobic granules after 6 months storage were employed in identical sequencing batch reactors (SBRs) using synthetic wastewater to investigate the impacts of different operational strategies on granules' reactivation process. The SBRs were operated under three operational strategies for reactivation of (a) different organic loading rate (OLR); (b) different ammonia concentration; and (c) different shear force (a superficial upflow air velocity). The results indicated that granules after long-term storage could be successfully recovered after 7 days of operation, and the excellent granule reactivation performance was closely related to the operational strategies, since inappropriate operational strategies could cause the outgrowth of filamentous bacteria and granule disintegration. Based on comprehensive comparison of reactivation performance under different operational strategies, the optimal operation strategy for granule reactivation was suggested at OLR of 0.8 kg COD/m(3)/day, ammonia concentration of 15-20 mg/L, and a superficial upflow air velocity of 2.6 cm/s. After 7 days operation under the optimal strategy, the dark brown granules (12 months storage) restored their bioactivities to previous state, in terms of COD removal efficiency (97.44%) and specific oxygen uptake rate (40.63 mg O(2)/g SS h(-1)). The results shed light on the future practical application of stored aerobic granules as bioseed for reactor fast start-up.
Dose estimate for personal music players including earphone sensitivity and characteristic
DEFF Research Database (Denmark)
Hammershøi, Dorte; Ordoñez Pizarro, Rodrigo Eduardo; Christensen, Anders Tornvig
2016-01-01
Personal music players can expose their listeners to high sound pressure levels over prolonged periods of time. The risk associated with prolonged listening is not readily available to the listener, and efforts are made to standardize dose estimates that may be displayed for the user...
Mishra, C.; Samantaray, A. K.; Chakraborty, G.
2016-05-01
Rolling element bearings are widely used in rotating machines and their faults can lead to excessive vibration levels and/or complete seizure of the machine. Under special operating conditions such as non-uniform or low speed shaft rotation, the available fault diagnosis methods cannot be applied for bearing fault diagnosis with full confidence. Fault symptoms in such operating conditions cannot be easily extracted through usual measurement and signal processing techniques. A typical example is a bearing in heavy rolling mill with variable load and disturbance from other sources. In extremely slow speed operation, variation in speed due to speed controller transients or external disturbances (e.g., varying load) can be relatively high. To account for speed variation, instantaneous angular position instead of time is used as the base variable of signals for signal processing purposes. Even with time synchronous averaging (TSA) and well-established methods like envelope order analysis, rolling element faults in rolling element bearings cannot be easily identified during such operating conditions. In this article we propose to use order tracking on the envelope of the wavelet de-noised estimate of the short-duration angle synchronous averaged signal to diagnose faults in rolling element bearing operating under the stated special conditions. The proposed four-stage sequential signal processing method eliminates uncorrelated content, avoids signal smearing and exposes only the fault frequencies and its harmonics in the spectrum. We use experimental data1
Estimated wind speed feed forward control for wind turbine operation optimisation
Energy Technology Data Exchange (ETDEWEB)
Van der Hooft, E.L.; Van Engelen, T.G. [ECN Wind Energy, Petten (Netherlands)
2004-11-01
For a pitch controlled variable speed wind turbine, a feed forward control structure based on the estimation of rotor averaged wind speed has been developed and analyzed. The additional control action will accelerate ordinary rotor speed feedback control to resist disturbances of wind speed turbulence and wind gusts. Wind speed estimation is based on reconstruction of aerodynamic torque from measurements and a priori knowledge of rotor behaviour. The theoretical base arises from the energy balance between captured aerodynamic energy from wind on the one hand and extracted electric energy (generator), stored kinetic energy (rotor inertia) and losses on the other hand. A tabular implementation for use in real-time control has been derived and evaluated by time domain simulations, stability analysis and parametric uncertainty studies. Without stability drawbacks, the proposed method has shown to be a powerful for reduction of rotor speed variations (30-40%) and wind gust suppression. Energy yield increase is feasible (0.9%) if temporarily torque excesses are not allowed.
Fundamental tone estimates for elliptic operators in divergence form and geometric applications
Directory of Open Access Journals (Sweden)
Gregório P. Bessa
2006-09-01
Full Text Available We establish a method for giving lower bounds for the fundamental tone of elliptic operators in divergence form in terms of the divergence of vector fields. We then apply this method to the Lr operator associated to immersed hypersurfaces with locally bounded (r + 1-th mean curvature Hr + 1 of the space forms Nn+ 1(c of constant sectional curvature c. As a corollary we give lower bounds for the extrinsic radius of closed hypersurfaces of Nn+ 1(c with Hr + 1 > 0 in terms of the r-th and (r + 1-th mean curvatures. Finally we observe that bounds for the Laplace eigenvalues essentially bound the eigenvalues of a self-adjoint elliptic differential operator in divergence form. This allows us to show that Cheeger's constant gives a lower bounds for the first nonzero Lr-eigenvalue of a closed hypersurface of Nn+ 1(c.Estabelecemos um método para obter limites inferiores para o tom fundamental de operadores elípticos em forma divergente em termos do divergente de campos de vetores. Aplicamos esse método para os operadores Lr associados a hipersuperfícies imersas nas formas espaciais Nn(c de curvatura seccional constante c com (r + 1-curvatura média Hr + 1 localmente limitada. Obtemos como corolário limites inferiores para o raio extrínseco de hipersuperfícies compactas das formas espaciais Nn(c com Hr + 1 > 0 em termos das r-ésima e r + 1-ésima curvatura médias. Finalmente, observamos que limites para os autovalores do Laplaciano essencialmente limitam os autovalores dos operadores elípticos em forma divergente. Isso permite mostrar que a constante de Cheeger limita inferiormente o primeiro autovalor não-nulo dos operadores Lr em hypersuperfícies compactas de Nn(c.
Green's function estimates for lattice Schrodinger operators and applications (AM-158)
Bourgain, Jean
2004-01-01
This book presents an overview of recent developments in the area of localization for quasi-periodic lattice Schrödinger operators and the theory of quasi-periodicity in Hamiltonian evolution equations. The physical motivation of these models extends back to the works of Rudolph Peierls and Douglas R. Hofstadter, and the models themselves have been a focus of mathematical research for two decades. Jean Bourgain here sets forth the results and techniques that have been discovered in the last few years. He puts special emphasis on so-called ""non-perturbative"" methods and the important role of
Directory of Open Access Journals (Sweden)
Bart Peeters
2007-01-01
Full Text Available During a football game, the ambient vibrations at the roof of a football stadium were recorded. A very large data set consisting of 4 hours of data, sampled at 80 Hz, is available. By a data reduction procedure, the complete data set could be analysed at once in a very short time. The data set was also split in shorter segments corresponding to certain events before, during and after the game to investigate the influence of varying operational conditions on the dynamic properties.
Semiclassical resolvent estimates for Schrödinger matrix operators with eigenvalues crossing.
Jecko, T
2001-01-01
For semiclassical Schrödinger matrix operators, we investigate the semiclassical Mourre theory to derive semiclassical bounds for the boundary values of the resolvent. We concentrate on the case where the eigenvalues of the symbol cross. Under the non-trapping condition on the eigenvalues of the symbol and under a condition on its matricial structure, we obtain the desired bounds for codimension one crossings. For codimension two crossings, we show that a geometrical condition at the crossing must hold to get the existence of a global escape function, required by the usual semiclassical Mourre theory.
Barriot, J. P.; Balmino, G.
1992-09-01
A novel method is presented for mapping line-of-sight gravity data (LOSGD) joining planetary probes and observers during Doppler tracking operations, with a view to geodetic and geophysical applications. LOSGD are in this case mapped as gravity anomalies along a radial direction, at constant altitude, using an inversion procedure in conjunction with a Tikhonov-Arsenine regularization method. The application of different regularization-parameter choices to a synthetic case is followed by application to the real case of Pioneer-Venus orbiter data for Venus' Gula Mons.
Bramanti, Marco
2011-01-01
We consider linear second order nonvariational partial differential operators of the kind a_{ij}X_{i}X_{j}+X_{0}, on a bounded domain of R^{n}, where the X_{i}'s (i=0,1,2,...,q, n>q+1) are real smooth vector fields satisfying H\\"ormander's condition and a_{ij} (i,j=1,2,...,q) are real valued, bounded measurable functions, such that the matrix {a_{ij}} is symmetric and uniformly positive. We prove that if the coefficients a_{ij} are H\\"older continuous with respect to the distance induced by the vector fields, then local Schauder estimates on X_{i}X_{j}u, X_{0}u hold; if the coefficients belong to the space VMO with respect to the distance induced by the vector fields, then local L^{p} estimates on X_{i}_{j}u, X_{0}u hold. The main novelty of the result is the presence of the drift term X_{0}, so that our class of operators covers, for instance, Kolmogorov-Fokker-Planck operators.
Directory of Open Access Journals (Sweden)
Tatenda C. Mbara
2016-01-01
Full Text Available The three-wheeler tuk-tuk, popular in Asian cities is now a common feature in many cities worldwide, across all five continents. Their growth has been attributed to their distinctive flexibility, stylistic simplicity and modest operational costs. In Johannesburg, the tuk-tuk represents a relatively new mode of public transport which stemmed from suggestions made by the local area residents association and other stakeholders to revamp the neighbourhood. The objective of the paper is to determine the operational and user travel characteristics of tuk-tuks as well as assessing their impacts. In Johannesburg, where competition from private transport operators can result in serious confrontation, the paper ascertains whether tuktuks pose a threat to other operators. Data was collected through telephonic interviews and electronic questionnaires. The results reveal that the tuk-tuk has filled a public transport gap by providing a much needed ‘first mile’/‘last mile’ service to community members.
Directory of Open Access Journals (Sweden)
Al-Hetari H.M. Abdulaziz
2016-01-01
Full Text Available The article presents the analysis of the main stages of professional activity of the operator of a management system by a production line of food products. Studied the question of the serious consequences of human error as the cause of the marriage in the manufacture of food products on automated lines. The nature of the error automated systems operators as a result of the deterioration of psychophysical state of the working person. The importance of modeling the signal generating emergency alarm, can significantly reduce the probability of release of potentially dangerous products. The optimality of the psychophysical state of the control system operator line of food production is highlighted as one of the main criteria for the rational organization of work. The problem of assessing changes in the human condition is also studied, participating in professional activities. The classification of types of functional states control over employee -depending on its purpose. Special attention in work is paid to an example of change of a psychophysical state, expressed in exhaustion of the worker of production. It gives a detailed description of the external signs of exhaustion in the comparative analysis of manual and mental work. The article shows the main tariff and qualification characteristics of activities of operators of lines in production of food products depending on their categories are specified. Describes a group of workers, depending on the operator's activity, indicating the brief description of each group. Based on the analysis of tariff and qualifying characteristics of lines of the operators in the production of food products of different categories, it shows that the range of qualifying categories covers almost al l groups of workers with the exception of the head of the operator. Highlight the desired differentiated approach to the assessment of psychophysiological state operators.
Practical method for estimating wind characteristics at potential wind-energy-conversion sites
Energy Technology Data Exchange (ETDEWEB)
Endlich, R. M.; Ludwig, F. L.; Bhumralkar, C. M.; Estoque, M. A.
1980-08-01
Terrain features and variations in the depth of the atmospheric boundary layer produce local variations in wind, and these variations are not depicted well by standard weather reports. A method is developed to compute local winds for use in estimating the wind energy available at any potential site for a wind turbine. The method uses the terrain heights for an area surrounding the site and a series of wind and pressure reports from the nearest four or five national Weather Service stations. An initial estimate of the winds in the atmospheric boundary layer is made, then these winds are adjusted to satisfy the continuity equation. In this manner the flow is made to reflect the influences of the terrain and the shape of the boundary-layer top. This report describes in detail the methodology and results, and provides descriptions of the computer programs, instructions for using them, and complete program listings.
Directory of Open Access Journals (Sweden)
B. Bayram
2006-01-01
Full Text Available Data concerning body measurements, milk yield and body weights data were analysed on 101 of Holstein Friesian cows. Phenotypic correlations indicated positive significant relations between estimated feed efficiency (EFE and milk yield as well as 4 % fat corrected milk yield, and between body measurements and milk yield. However, negative correlations were found between the EFE and body measurements indicating that the taller, longer, deeper and especially heavier cows were not to be efficient as smaller cows
On the Aleksandrov-Bakel'man-Pucci Estimate for Some Elliptic and Parabolic Nonlinear Operators
Argiolas, Roberto; Charro, Fernando; Peral, Ireneo
2011-12-01
In this work we prove the Aleksandrov-Bakel'man-Pucci estimate for (possibly degenerate) nonlinear elliptic and parabolic equations of the form -div left( Fleft( nabla u(x)right) right) =fleft(xright) quad in Ω subset mathbb{R}n and ut(x,t)-div left( Fleft( nabla u(x,t)right) right) =fleft( x,tright) quad in Qsubset mathbb{R}^{n+1} for F a {fancyscript{C}^1} monotone field under some suitable conditions. Examples of applications such as the p-Laplacian and the Mean Curvature Flow are considered, as well as extensions of the general results to equations that are not in divergence form, such as the m-curvature flow.
Energy Technology Data Exchange (ETDEWEB)
A. Unger; S. Finsterle; G. Bodvarsson
2003-06-06
Radon gas concentrations have been monitored as part of the operation of a tunnel (the Exploratory Studies Facility-ESF) at Yucca Mountain to ensure worker safety. The objective of this study was to examine the potential use of the radon data to estimate large-scale formation properties of fractured tuffs. This objective was examined by developing a numerical model, based upon the characteristics of the ESF and the Topopah Spring welded (TSw) tuff unit, capable of predicting radon concentrations for prescribed ventilation conditions. The model was used to address two specific issues. First, it was used to estimate the permeability and porosity of the fractures in the TSw at the length scale of the ESF and extending tens of meters into the TSw, which surrounds the ESF. Second, the model was used to understand the mechanism leading to radon concentrations exceeding a specified level within the ESF. The mechanism controlling radon concentrations in the ESF is a function of atmospheric barometric fluctuations being propagated down the ESF along with ventilated air flow and the slight suction induced by the ventilation exhaust fans at the South Portal of the ESF. These pressure fluctuations are dampened in the TSw fracture continuum according to its permeability and porosity. Consequently, as the barometric pressure in the ESF drops rapidly, formation gases from the TSw are pulled into the ESF, resulting in an increase in radon concentrations. Model calibration to both radon concentrations measured in the ESF and gas-phase pressure fluctuations in the TSw yielded concurrent estimates of TSw fracture permeability and porosity of l x 10{sup -11} m{sup 2} and 0.00034, respectively. The calibrated model was then used as a design tool to predict the effect of adjusting the current ventilation-system operation strategy for reducing the probability of radon gas concentrations exceeding a specified level.
Todorov, Emanuel
2005-05-01
Optimality principles of biological movement are conceptually appealing and straightforward to formulate. Testing them empirically, however, requires the solution to stochastic optimal control and estimation problems for reasonably realistic models of the motor task and the sensorimotor periphery. Recent studies have highlighted the importance of incorporating biologically plausible noise into such models. Here we extend the linear-quadratic-gaussian framework--currently the only framework where such problems can be solved efficiently--to include control-dependent, state-dependent, and internal noise. Under this extended noise model, we derive a coordinate-descent algorithm guaranteed to converge to a feedback control law and a nonadaptive linear estimator optimal with respect to each other. Numerical simulations indicate that convergence is exponential, local minima do not exist, and the restriction to nonadaptive linear estimators has negligible effects in the control problems of interest. The application of the algorithm is illustrated in the context of reaching movements. A Matlab implementation is available at www.cogsci.ucsd.edu/~todorov.
Estimation of sediment yield during storms based on soil and watershed geomorphology characteristics
Lee, Kwan Tun; Yang, Chi-Cheng
2010-03-01
SummaryConcentrated rainfall usually results in serious soil erosion on steep hillslopes. Since the itinerary of the eroded sediment is complicated, estimating watershed erosion during storms is practically difficult. A physically-based approach for sediment yield estimation during storms was proposed in this study. By using soil and watershed geomorphologic information, analytical solutions for sediment travel time in different orders of overland areas and channels were derived to develop a geomorphologic instantaneous unit sedimentgraph (GIUS) which showed the temporal distribution of sediment discharge resulting from an instantaneous rainfall excess input. The resultant GIUS was a function of the rainfall excess intensity and sediment delivery ratio. The linearity restriction of the unit hydrograph theory was relaxed. Sediment yields during storm events were calculated by convoluting rainfall intensities with the proposed GIUS, which had been verified by using data from the Goodwin Creek Experimental Watershed in Mississippi, the United States. The simulated and the measured sediment yields were in good agreement for the test storms. Sensitivity of the sedimentgraph to the model parameters was also investigated. The proposed model was considered a promising application for sediment yield estimation in the field of water resources design.
Johnson, Nathan H.
This dissertation is concerned with several problems of instrumentation and data analysis encountered by the Apache Point Observatory Lunar Laser-ranging Operation. Chapter 2 considers crosstalk between elements of a single-photon avalanche photodiode detector. Experimental and analytic methods were developed to determine crosstalk rates, and empirical findings are presented. Chapter 3 details electronics developments that have improved the quality of data collected by detectors of the same type. Chapter 4 explores the challenges of estimating gravitational parameters on the basis of ranging data collected by this and other experiments and presents resampling techniques for the derivation of standard errors for estimates of such parameters determined by the Planetary Ephemeris Program (PEP), a solar-system model and data-fitting code. Possible directions for future work are discussed in Chapter 5. A manual of instructions for working with PEP is presented as an appendix.
Energy Technology Data Exchange (ETDEWEB)
Johnsen, Boel [Haukeland University Hospital, Centre for Nuclear Medicine and PET, Department of Radiology, P.O. Box 1400, Bergen (Norway); Fasmer, Kristine Eldevik [Haukeland University Hospital, Department of Oncology, Medical Physics Section, Bergen (Norway); Boye, Kjetil [Norwegian Radium Hospital, Oslo University Hospital, Department of Oncology, Oslo (Norway); Rosendahl, Karen; Aukland, Stein Magnus [Haukeland University Hospital, Department of Radiology, Paediatric Section, Bergen (Norway); University of Bergen, Department of Clinical Medicine, Bergen (Norway); Trovik, Clement [University of Bergen, Department of Clinical Medicine, Bergen (Norway); Haukeland University Hospital, Department of Surgery, Orthopaedic Section, Bergen (Norway); Biermann, Martin [Haukeland University Hospital, Centre for Nuclear Medicine and PET, Department of Radiology, P.O. Box 1400, Bergen (Norway); University of Bergen, Department of Clinical Medicine, Bergen (Norway)
2017-01-15
Patients with Ewing sarcoma are subject to various diagnostic procedures that incur exposure to ionising radiation. To estimate the radiation doses received from all radiologic and nuclear imaging episodes during diagnosis and treatment, and to determine whether {sup 18}F-fluorodeoxyglucose positron emission tomography - computed tomography ({sup 18}F-FDG PET-CT) is a major contributor of radiation. Twenty Ewing sarcoma patients diagnosed in Norway in 2005-2012 met the inclusion criteria (age <30 years, operable disease, uncomplicated chemotherapy and surgery, no metastasis or residual disease within a year of diagnosis). Radiation doses from all imaging during the first year were calculated for each patient. The mean estimated cumulative radiation dose for all patients was 34 mSv (range: 6-70), radiography accounting for 3 mSv (range: 0.2-12), CT for 13 mSv (range: 2-28) and nuclear medicine for 18 mSv (range: 2-47). For the patients examined with PET-CT, the mean estimated cumulative effective dose was 38 mSv, of which PET-CT accounted for 14 mSv (37%). There was large variation in number and type of examinations performed and also in estimated cumulative radiation dose. The mean radiation dose for patients examined with PET-CT was 23% higher than for patients not examined with PET-CT. (orig.)
A new scenario-based approach to damage detection using operational modal parameter estimates
Hansen, J. B.; Brincker, R.; López-Aenlle, M.; Overgaard, C. F.; Kloborg, K.
2017-09-01
In this paper a vibration-based damage localization and quantification method, based on natural frequencies and mode shapes, is presented. The proposed technique is inspired by a damage assessment methodology based solely on the sensitivity of mass-normalized experimental determined mode shapes. The present method differs by being based on modal data extracted by means of Operational Modal Analysis (OMA) combined with a reasonable Finite Element (FE) representation of the test structure and implemented in a scenario-based framework. Besides a review of the basic methodology this paper addresses fundamental theoretical as well as practical considerations which are crucial to the applicability of a given vibration-based damage assessment configuration. Lastly, the technique is demonstrated on an experimental test case using automated OMA. Both the numerical study as well as the experimental test case presented in this paper are restricted to perturbations concerning mass change.
Olivera-Guerra, L.; Mattar, C.; Merlin, O.; Durán-Alarcón, C.; Santamaría-Artigas, A.; Fuster, R.
2017-06-01
Monitoring evapotranspiration in arid and semi-arid environments plays a key role in water irrigation scheduling for water use efficiency. This work presents an operational method for evapotranspiration retrievals based on disaggregated Land Surface Temperature (LST). The retrieved LSTs from Landsat-8 and MODIS data were merged in order to provide an 8-day composite LST product at 100 × 100 m resolution. The method was tested in the arid region of Copiapó, Chile using data from years 2013-2014 and validated using data from years 2015-2016. In-situ measurements from agrometeorological stations such as air temperature and potential evapotranspiration (ET0) estimated at the location were used in the ET estimation method. The disaggregation method was developed by taking into account (1) the spatial relationship between Landsat-8 and MODIS LST, (2) the spatial relationship between LST and the Normalized Difference Vegetation Index (NDVI) at high spatial resolution (Landsat-8), and (3) the temporal variations along the year of both relationships aforementioned. The comparison between disaggregated LST at 100 m resolution and in situ LST measurements presents a coefficient of determination (r2), in average, equal to 0.70 and a RMSE equal to 3.6 K. The disaggregated LST was used in an operational model to estimate the actual evapotranspiration (ETa). The ETa shows good results in terms of seasonal variations and in comparison to the evapotranspiration estimated by using crop coefficients (kc). The comparison between remotely sensed and in situ ETa presents an overall r2 close to 0.67 and a RMSE equal to 0.6 mm day-1 for both crops. These results are important for further improvements in water use sustainability in the Copiapó valley, which is currently affected by high water demand.
Tsui, Po-Hsiang; Wang, Shyh-Hau
2004-10-01
The effect of transducer characteristics on the sensitivity of the Nakagami parameter to detect the variation of scatterer concentrations was studied. The rationale for this study stems from our pilot results which showed that the Nakagami parameters, estimated using a nonfocused transducer were not as sensitive as those of measurements using a commercial ultrasonic scanner in previous reports. This discrepancy may be attributed to the effects of transducer characteristics relative to the size of the resolution cell as verified by measurements of phantoms and 2-D computer simulations. The Nakagami parameter as a function of scatterer concentration was calculated using backscattered signals acquired from the scattering medium of different scatterer concentrations ranging from 2 to 32 scatterers/mm(3) using both 5 MHz nonfocused and focused transducers. Experimental and simulation results obtained from the nonfocused transducer represent that their respective Nakagami parameters increased from 1.17 to 1.31 and from 0.82 to 1.01 corresponding to the increase of scatterer concentrations. For the results obtained from the focused transducer, their average Nakagami parameters increased from 0.27 to 0.72 and from 0.33 to 0.81. These consistent results demonstrated that Nakagami parameter estimated using a focused transducer tends to be more sensitive than that by a nonfocused transducer to detect the variation of low scatterer concentration. This difference is fully due to the effect of transducer characteristics associated with the effective number of scatterers in the resolution cell.
Directory of Open Access Journals (Sweden)
Pešić Milan P.
2012-01-01
Full Text Available A numerical simulation of the radiological consequences of the RB reactor reactivity excursion accident, which occurred on October 15, 1958, and an estimation of the total doses received by the operators were run by the MCNP5 computer code. The simulation was carried out under the same assumptions as those used in the 1960 IAEA-organized experimental simulation of the accident: total fission energy of 80 MJ released in the accident and the frozen positions of the operators. The time interval of exposure to high doses received by the operators has been estimated. Data on the RB1/1958 reactor core relevant to the accident are given. A short summary of the accident scenario has been updated. A 3-D model of the reactor room and the RB reactor tank, with all the details of the core, created. For dose determination, 3-D simplified, homogenised, sexless and faceless phantoms, placed inside the reactor room, have been developed. The code was run for a number of neutron histories which have given a dose rate uncertainty of less than 2%. For the determination of radiation spectra escaping the reactor core and radiation interaction in the tissue of the phantoms, the MCNP5 code was run (in the KCODE option and “mode n p e”, with a 55-group neutron spectra, 35-group gamma ray spectra and a 10-group electron spectra. The doses were determined by using the conversion of flux density (obtained by the F4 tally in the phantoms to doses using factors taken from ICRP-74 and from the deposited energy of neutrons and gamma rays (obtained by the F6 tally in the phantoms’ tissue. A rough estimation of the time moment when the odour of ozone was sensed by the operators is estimated for the first time and given in Appendix A.1. Calculated total absorbed and equivalent doses are compared to the previously reported ones and an attempt to understand and explain the reasons for the obtained differences has been made. A Root Cause Analysis of the accident was done and
García-Rigo, Alberto; Núñez, Marlon; Qahwaji, Rami; Ashamari, Omar; Jiggens, Piers; Pérez, Gustau; Hernández-Pajares, Manuel; Hilgers, Alain
2016-07-01
A web-based prototype system for predicting solar energetic particle (SEP) events and solar flares for use by space launch operators is presented. The system has been developed as a result of the European Space Agency (ESA) project SEPsFLAREs (Solar Events Prediction system For space LAunch Risk Estimation). The system consists of several modules covering the prediction of solar flares and early SEP Warnings (labeled Warning tool), the prediction of SEP event occurrence and onset, and the prediction of SEP event peak and duration. In addition, the system acquires data for solar flare nowcasting from Global Navigation Satellite Systems (GNSS)-based techniques (GNSS Solar Flare Detector, GSFLAD and the Sunlit Ionosphere Sudden Total Electron Content Enhancement Detector, SISTED) as additional independent products that may also prove useful for space launch operators.
Singha, Suman; Vespe, Michele; Trieschmann, Olaf
2013-08-15
Today the health of ocean is in danger as it was never before mainly due to man-made pollutions. Operational activities show regular occurrence of accidental and deliberate oil spill in European waters. Since the areas covered by oil spills are usually large, satellite remote sensing particularly Synthetic Aperture Radar represents an effective option for operational oil spill detection. This paper describes the development of a fully automated approach for oil spill detection from SAR. Total of 41 feature parameters extracted from each segmented dark spot for oil spill and 'look-alike' classification and ranked according to their importance. The classification algorithm is based on a two-stage processing that combines classification tree analysis and fuzzy logic. An initial evaluation of this methodology on a large dataset has been carried out and degree of agreement between results from proposed algorithm and human analyst was estimated between 85% and 93% respectively for ENVISAT and RADARSAT.
Institute of Scientific and Technical Information of China (English)
Wanjiang; WANG
2015-01-01
First of all,this paper discusses the scale agricultural operation of China from the aspects of practical exploration and rational thinking. Later,it puts forward the concept of further promoting scale agricultural operation according to the present conditions of China,which includes encouraging large household pattern and scale breeding,developing various forms of socialized agricultural services,promoting agriculture industrialization,accelerating regional distribution of advantageous agricultural products and promoting the progress in agricultural science and technology comprehensively.
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XU, F.
2013-05-01
Full Text Available Orbital Friction Vibration Actuator (OFVA is a core component of Orbital Friction Welding (OFW, which is a novel apertureless welding technology utilizing friction heat to implement solid-state joining. In this paper, topology and operational principle of OFVA are introduced, the analytical formulas of the electromagnetic force for the x and y directions, which can drive the mover to generate a circular motion trajectory, are derived, and the characteristic of static electromagnetic force is predicted by analytical method and 2-D (two-dimensional FEM (finite element method, 3-D and measurement. The coupled magnetic field-circuit-motion simulation models which are driven by current and voltage source are established, respectively, and some of its operational characteristics are analyzed. Simulation and experiment validate theoretical analysis and the feasibility of the fabricated prototype, demonstrate the good performance of the OFVA, and provide valuable reference for engineering applications.
Energy Technology Data Exchange (ETDEWEB)
Buczko, U.; Gerke, H.H. [Brandenburg University of Technology, Cottbus (Germany)
2005-07-01
Mine soil materials may be viewed as man-made systems that consist of spatially disordered soil and sediment components, which are in an initial stage of soil development. A question is whether methods and approaches developed for natural soils, may also be used for such artificially created soil materials. The applicability of the Arya and Paris pedotransfer function to obtain hydraulic properties from the particle size distribution and bulk density was tested for lignitic mine soil material of the Lusatian Lignite Mining District in eastern Germany. The scaling factor a in this model was evaluated by (I) fitting of the water retention curves estimated with the Arya-Paris model (APM) to measured water retention data and (ii) interpretation of a as a fractal dimension of the pore channels and derivation of this fractal dimension from the fractal dimension of the particle size distribution. The two tested fractal approaches resulted in relatively inaccurate predictions of the water content. The use of a single fitted a value for each depth yielded a values between 1.05 and 1.47. Because of the inability of the APM to account for residual water contents in this sandy soil material, a correction was applied. The cumulative mass fraction fractal method did not improve the estimation in comparison with the retention curves calculated with a constant a value of 1.38. The closest fits with the data were obtained by using a variable a value that depended on the particle size. The accuracy of the predictions of the APM in the higher suction range could be improved (lower mean deviations and root mean square deviations of water content) by using a linear water content-dependent correction factor. Better estimates of water retention in the relatively dry range may be significant for simulation of water budgets of mine spoil sites in the Lusatian Mining District.
Non-linear parameter estimation for the LTP experiment: analysis of an operational exercise
Congedo, G; Ferraioli, L; Hueller, M; Vitale, S; Hewitson, M; Nofrarias, M; Monsky, A; Armano, M; Grynagier, A; Diaz-Aguilo, M; Plagnol, E; Rais, B
2011-01-01
The precursor ESA mission LISA-Pathfinder, to be flown in 2013, aims at demonstrating the feasibility of the free-fall, necessary for LISA, the upcoming space-born gravitational wave observatory. LISA Technology Package (LTP) is planned to carry out a number of experiments, whose main targets are to identify and measure the disturbances on each test-mass, in order to reach an unprecedented low-level residual force noise. To fulfill this plan, it is then necessary to correctly design, set-up and optimize the experiments to be performed on-flight and do a full system parameter estimation. Here we describe the progress on the non-linear analysis using the methods developed in the framework of the \\textit{LTPDA Toolbox}, an object-oriented MATLAB Data Analysis environment: the effort is to identify the critical parameters and remove the degeneracy by properly combining the results of different experiments coming from a closed-loop system like LTP.
Estimation of f-validity of Geometrical Objects with OWA Operator Weights
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Abdul Rahman
2014-01-01
Full Text Available In the age of sophisticated crimes and terrorism, there is a requirement to develop a perception based multi criteria decision making system that can reveal the hidden clues in the environment of uncertainty. The crime has no fixed dimension to be carried out in. But, still there remain some imprecise clues for the crime site investigation team and precise interpretation of these clues is impossible. That is the place where role of proposed extended fuzzy logic (FLe comes into play. Moreover, for decision making, crime site investigation team has to consider multi criteria with different weights under the uncertainty. So, Extended Fuzzy Logic and Ordered weighted Averaging (OWA may be taken together as a double folded milestone in revealing the uncertainty in the world of computational forensic. The concept of unprecisiated fuzzy logic (Flu was introduced by Zadeh. When a perfect solution cannot be given or process falls excessively costly then the role of concept of Flu comes into play. This novel concept provides the basis for FLe. In order to have a better understanding of Flu, the concept of fuzzy geometry (f-geometry is introduced. The proposed work is based on Sketching with Word technique. We have introduced some fuzzy theorems (f-theorems in proposed work. These f-theorems can be used for estimating the membership value of fuzzy objects in f-geometry. These f-objects may play vital role for identifying clues in computational forensic.
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Sri Legowo
2009-11-01
Full Text Available Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP.The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir.Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008.
Distance estimate and progenitor characteristics of SN 2005cs in M51
Takats, K; Takats, Katalin; Vinko, Jozsef
2006-01-01
Distance to the Whirlpool Galaxy (M51, NGC 5194) is estimated using published photometry and spectroscopy of the Type II-P supernova SN 2005cs. Both the Expanding Photosphere Method (EPM) and the Standard Candle Method (SCM), suitable for SNe II-P, were applied. The average distance (7.1 \\pm 1.2 Mpc) is in good agreement with earlier SBF- and PNLF-based distances, but slightly longer than the distance obtained by Baron et al. for SN 1994I via the Spectral Fitting Expanding Atmosphere Method (SEAM). Since SN 2005cs exhibited low expansion velocity during the plateau phase, similarly to SN 1999br, the constants of SCM were re-calibrated including the data of SN 2005cs as well. The new relation is better constrained in the low velocity regime (v_{ph}(50) ~ 1500 - 2000$ km/s), that may result in better distance estimates for such SNe. The physical parameters of SN 2005cs and its progenitor are re-evaluated based on the updated distance. All the available data support the low-mass (~ 9 M_\\odot) progenitor scenario...
DEM Resolution Impact on the Estimation of the Physical Characteristics of Watersheds by Using SWAT
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Waranyu Buakhao
2016-01-01
Full Text Available A digital elevation model (DEM is an important spatial input for automatic extraction of topographic parameters for the soil and water assessment tool (SWAT. The objective of this study was to investigate the impact of DEM resolution (from 5 to 90 m on the delineation process of a SWAT model with two types of watershed characteristics (flat area and mountain area and three sizes of watershed area (about 20,000, 200,000, and 1,500,000 hectares. The results showed that the total lengths of the streamline, main channel slope, watershed area, and area slope were significantly different when using the DEM datasets to delineate. Delineation using the SRTM DEM (90 m, ASTER DEM (30 m, and LDD DEM (5 m for all watershed characteristics showed that the watershed sizes and shapes obtained were only slightly different, whereas the area slopes obtained were significantly different. The total lengths of the generated streams increased when the resolution of the DEM used was higher. The stream slopes obtained using the small area sizes were insignificant, whereas the slopes obtained using the large area sizes were significantly different. This suggests that water resource model users should use the ASTER DEM as opposed to a finer resolution DEM for model input to save time for the model calibration and validation.
DEFF Research Database (Denmark)
Andersen, Lars Vabbersgaard; Sørensen, John Dalsgaard; Kim, Sun-Bin;
2015-01-01
, and pile–soil interaction is modelled by the Winkler approach with nonlinear p–y curves for the soil resistance. The 5MW NREL reference wind turbine is employed for load estimation, utilizing the aeroelastic code FAST. The study includes comparison of monopile capacities based on a single CPT as well......Different approaches to estimation of the characteristic undrained shear strength of soil are discussed, based on 12 cone penetration tests (CPTs) carried out within a soil volume representative of an offshore monopile foundation. The paper is focused on the statistical treatment of the data...... as multiple CPTs. Comparisons are made between results obtained from a single CPT and those from all the CPTs at the site. The influence of assuming few or many layers in the deterministic soil model is assessed, and different assumptions regarding the statistical distribution of the data are compared...
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E. de Coning
2010-11-01
Full Text Available Extreme weather related to heavy or more frequent precipitation events seem to be a likely possibility for the future of our planet. While precipitation measurements can be done by means of rain gauges, the obvious disadvantages of point measurements are driving meteorologists towards remotely sensed precipitation methods. In South Africa more sophisticated and expensive nowcasting technology such as radar and lightning networks are available, supported by a fairly dense rain gauge network of about 1500 gauges. In the rest of southern Africa rainfall measurements are more difficult to obtain. The availability of the local version of the Unified Model and the Meteosat Second Generation satellite data make these products ideal components of precipitation measurement in data sparse regions such as Africa. In this article the local version of the Hydroestimator (originally from NOAA/NESDIS is discussed as well as its applications for precipitation measurement in this region. Hourly accumulations of the Hydroestimator are currently used as a satellite based precipitation estimator for the South African Flash Flood Guidance system. However, the Hydroestimator is by no means a perfect representation of the real rainfall. In this study the Hydroestimator and the stratiform rainfall field from the Unified Model are both bias corrected and then combined into a new precipitation field which can feed into the South African Flash Flood Guidance system. This new product should provide a more accurate and comprehensive input to the Flash Flood Guidance systems in South Africa as well as southern Africa. In this way the southern African region where data is sparse and very few radars are available can have access to more accurate flash flood guidance.
Silk, Aaron; Lenton, Gavin; Savage, Robbie; Aisbett, Brad
2017-07-28
Search and rescue operations are necessary in locating, assisting and recovering individuals lost or in distress. In Australia, land-based search and rescue roles require a range of physically demanding tasks undertaken in dynamic and challenging environments. The aim of the current research was to identify and characterise the physically demanding tasks inherent to search and rescue operation personnel within Australia. These aims were met through a subjective job task analysis approach. In total, 11 criterion tasks were identified by personnel. These tasks were the most physically demanding, frequently occurring and operationally important tasks to these specialist roles. Muscular strength was the dominant fitness component for 7 of the 11 tasks. In addition to the discrete criterion tasks, an operational scenario was established. With the tasks and operational scenario identified, objective task analysis procedures can be undertaken so that practitioners can implement evidence-based strategies, such as physical selection procedures and task-based physical training programs, commensurate with the physical demands of search and rescue job roles. Practitioner Summary: The identification of physically demanding tasks amongst specialist emergency service roles predicates health and safety strategies which can be incorporated into organisations. Knowledge of physical task parameters allows employers to mitigate injury risk through the implementation of strategies modelled on the precise physical demands of the role.
Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors
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VLAD, I.
2014-02-01
Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.
Dynamic Performance Characteristics of a Curved Slider Bearing Operating with Ferrofluids
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Udaya P. Singh
2012-01-01
Full Text Available In the present theoretical investigation, the effect of ferrofluid on the dynamic characteristics of curved slider bearings is presented using Shliomis model which accounts for the rotation of magnetic particles, their magnetic moments, and the volume concentration in the fluid. The modified Reynolds equation for the dynamic state of the bearing is obtained. The results of dynamic stiffness and damping characteristics are presented. It is observed that the effect of rotation of magnetic particles improves the stiffness and damping capacities of the bearings.
The characteristics of the combustion process occurring under real operating conditions of traction
Longwic, R.; Sander, P.
2016-09-01
The authors deal with the issues of the Diesel engine under dynamic conditions. The conditions of the dynamic operation of the engine have most frequently been mapped by the method of free acceleration of the engine caused by the change of the position of the fuel dose lever. The article presents the results of indication of the traction Diesel engine under real operating conditions. This allows for the use of a mobile system to indicate the AVL engine built in the vehicle in research. We analysed a number of thermodynamic parameters of the combustion process in various dynamic states, typical for the process of actual operation of the engine, such as working in start-up conditions and immediately after, working in conditions of acceleration and coasting. Formulated conclusions significantly expand the area of knowledge concerning the functioning of the internal combustion engine in dynamic conditions.
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Juan PuigdefÃƒÂ¡bregas
2007-06-01
Full Text Available Three operative models with minimum input data requirements for estimatingthe partition of available surface energy into sensible and latent heat flux using ASTERdata have been evaluated in a semiarid area in SE Spain. The non-evaporative fraction(NEF is proposed as an indicator of the surface water deficit. The best results wereachieved with NEF estimated using the Ã¢Â€ÂœSimplified relationshipÃ¢Â€Â for unstable conditions(NEFSeguin and with the S-SEBI (Simplified Surface Energy Balance Index modelcorrected for atmospheric conditions (NEFS-SEBIt, which both produced equivalent results.However, results with a third model, NEFCarlson, that estimates the exchange coefficient forsensible heat transfer from NDVI, were unrealistic for sites with scarce vegetation cover.These results are very promising for an operative monitoring of the surface water deficit,as validation with field data shows reasonable errors, within those reported in the literature(RMSE were 0.18 and 0.11 for the NEF, and 29.12 Wm-2 and 25.97 Wm-2 for sensible heatflux, with the Seguin and S-SEBIt models, respectively.
Operational characteristics of tractors driven by children on farms in the United States and Canada.
Marlenga, B; Pickett, W; Berg, R L; Murphy, D
2004-01-01
Farm tractors are an important source of traumatic injury for children on farms. There is, however, no documentation about the age and size of tractors that children are operating and little information about the frequency with which rollover protective structures (ROPS) are used. This study described tractors that children on farms in the U.S. and Canada were operating by age, horsepower, and the presence of ROPS, according to the age and gender of the farm children involved. As a sub-analysis of data compiled during a randomized controlled trial, a descriptive analysis was completed on work exposure data collected by telephone interview. Of the 1,113 children involved in the trial, 522 (47%) were reported to perform at least one job that involved the operation of a farm tractor, and 408 (36.7%) were operating tractors of at least 20 horsepower. The majority of these children were male. There was a wide range of ages and sizes of tractors operated. However, the majority of tractors were between 20 and 70 horsepower and manufactured after 1970. Nearly one-half of the tractors were equipped with ROPS, and these tended to be newer and larger tractors. This analysis provides new data about the broad range of tractors driven by farm children in the U.S. and Canada. The findings point to a need to re-examine the reliance on a single voluntary standard to mitigate the hazard of tractor rollovers and the need for an enhanced safety policy requiring all tractors operated by children be equipped with ROPS.
Amako, Eri; Enjoji, Takaharu; Uchida, Satoshi; Tochikubo, Fumiyoshi
Constant monitoring and immediate control of fermentation processes have been required for advanced quality preservation in food industry. In the present work, simple estimation of metabolic states for heat-injured Escherichia coli (E. coli) in a micro-cell was investigated using dielectrophoretic impedance measurement (DEPIM) method. Temporal change in the conductance between micro-gap (ΔG) was measured for various heat treatment temperatures. In addition, the dependence of enzyme activity, growth capacity and membrane situation for E. coli on heat treatment temperature was also analyzed with conventional biological methods. Consequently, a correlation between ΔG and those biological properties was obtained quantitatively. This result suggests that DEPIM method will be available for an effective monitoring technique for complex change in various biological states of microorganisms.
Nole, Gabriele; Scorza, Francesco; Lanorte, Antonio; Manzi, Teresa; Lasaponara, Rosa
2015-04-01
This paper aims to present the development of a tool to integrate time series from active and passive satellite sensors (such as of MODIS, Vegetation, Landsat, ASTER, COSMO, Sentinel) into a virtual laboratory to support studies on landscape and archaeological landscape, investigation on environmental changes, estimation and monitoring of natural and anthropogenic risks. The virtual laboratory is composed by both data and open source tools specifically developed for the above mentioned applications. Results obtained for investigations carried out using the implemented tools for monitoring land degradation issues and subtle changes ongoing on forestry and natural areas are herein presented. In detail MODIS, SPOT Vegetation and Landsat time series were analyzed comparing results of different statistical analyses and the results integrated with ancillary data and evaluated with field survey. The comparison of the outputs we obtained for the Basilicata Region from satellite data analyses and independent data sets clearly pointed out the reliability for the diverse change analyses we performed, at the pixel level, using MODIS, SPOT Vegetation and Landsat TM data. Next steps are going to be implemented to further advance the current Virtual Laboratory tools, by extending current facilities adding new computational algorithms and applying to other geographic regions. Acknowledgement This research was performed within the framework of the project PO FESR Basilicata 2007/2013 - Progetto di cooperazione internazionale MITRA "Remote Sensing tecnologies for Natural and Cultural heritage Degradation Monitoring for Preservation and valorization" funded by Basilicata Region Reference 1. A. Lanorte, R Lasaponara, M Lovallo, L Telesca 2014 Fisher-Shannon information plane analysis of SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series to characterize vegetation recovery after fire disturbance International Journal of Applied Earth Observation and
Bak, S.; Smith, J. M.; Hesser, T.; Bryant, M. A.
2016-12-01
Near-coast wave models are generally validated with relatively small data sets that focus on analytical solutions, specialized experiments, or intense storms. Prior studies have compiled testbeds that include a few dozen experiments or storms to validate models (e.g., Ris et al. 2002), but few examples exist that allow for continued model evaluation in the nearshore and surf-zone in near-realtime. The limited nature of these validation sets is driven by a lack of high spatial and temporal resolution in-situ wave measurements and the difficulty in maintaining these instruments on the active profile over long periods of time. The US Army Corps of Engineers Field Research Facility (FRF) has initiated a Coastal Model Test-Bed (CMTB), which is an automated system that continually validates wave models (with morphological and circulation models to follow) utilizing the rich data set of oceanographic and bathymetric measurements collected at the FRF. The FRF's cross-shore wave array provides wave measurements along a cross-shore profile from 26 m of water depth to the shoreline, utilizing various instruments including wave-rider buoys, AWACs, aquadopps, pressure gauges, and a dune-mounted lidar (Brodie et al. 2015). This work uses the CMTB to evaluate the performance of a phase-averaged numerical wave model, STWAVE (Smith 2007, Massey et al. 2011) over the course of a year at the FRF in Duck, NC. Additionally, from the BathyDuck Experiment in October 2015, the CMTB was used to determine the impact of applying the depth boundary condition for the model from monthly acoustic bathymetric surveys in comparison to hourly estimates using a video-based inversion method (e.g., cBathy, Holman et al. 2013). The modeled wave parameters using both bathymetric boundary conditions are evaluated using the FRF's cross-shore wave array and two additional cross-shore arrays of wave measurements in 2 to 4 m water depth from BathyDuck in Fall, 2015.
Leitao, R.C.; Santaellla, S.T.; Haandel, van A.C.; Zeeman, G.; Lettinga, G.
2011-01-01
This work aims to evaluate the hydrodynamic properties of the sludge bed of Upflow Anaerobic Sludge Blanket (UASB) reactors based on its settleability and expansion characteristics. The methodologies used for the evaluation of the settleability of aerobic activated sludge, and for the expansibility
7 CFR 42.140 - Operating Characteristic (OC) curves for on-line sampling and inspection.
2010-01-01
... defects in the sample. (e) The next plan that is listed in the column headed 6 for an AQL of 0.25 is a... total sample, the lot will be rejected. The other double sampling plans operate in a similar manner with... AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF...
Prediction of Operating Characteristics of Electrotechnical Devices using Artificial Neural Networks
Directory of Open Access Journals (Sweden)
PASCA Alexandra
2014-05-01
Full Text Available The paper purpose is to emphasize the possibilities and the advantages to use the artificial intelligence techniques for operating mode prediction of electrotechnical devices. The considered application consists of the analysis of behavior of an inductive proximity sensor at variation of design parameters.
Detector evaluation for improved situational awareness: Receiver operator characteristic curve based
Wuijckhuijse, A.L. van; Nieuwenhuizen, M.S.
2016-01-01
In military and civilian operations good situational awareness is a prerequisite to make proper decisions. The situational awareness is among others based upon intelligence, threat analysis and detection, altogether element of the so-called DIM (detection, identification, monitoring) system. In case
Prediction of Operating Characteristics of Electrotechnical Devices using Artificial Neural Networks
PASCA Alexandra; MICU Dan Doru; Czumbil, Levente
2014-01-01
The paper purpose is to emphasize the possibilities and the advantages to use the artificial intelligence techniques for operating mode prediction of electrotechnical devices. The considered application consists of the analysis of behavior of an inductive proximity sensor at variation of design parameters.
Institute of Scientific and Technical Information of China (English)
GUO Xiaoyan; ZHANG Zhenjia; FANG Lin; SU Liguo
2006-01-01
A pilot plant study on a polyvinylchloride hollow fiber ultrafiltration membrane process was conducted for treating surface water.The membrane system was operated in the dead-end filtration mode under different constant permeate fluxes.The results show that the optimized operation ( transmembrane pressure≤0.1 Mpa,filtration time≤30 min) with a hydraulic cleaning (30 s) and a chemical cleaning (30 min,the chemical cleaning was performed after 16 cycles of filtration ) en ures a quite steady flux (1 100 L/(m2·h · Mpa)) and good permeate quality (turbidity ＜0.1NTU ).A full-scale plant can be suggested to operate with a mixed strategy of constant permeate flux mode (transmembrane pressure ≤0.1 Mpa) and constant transmembrane pressure mode.When the temperature of raw water becomes below 5 ℃,a constant transmembrane pressure mode should be used; otherwise a constant permeate flux mode (transmembrane pressure ≤ 0.1 Mpa) can be operated.In this way,irreversible fouling of ultrafiltration membrane can be minimized to keep a stable flux and make the life of membrane longer.
Detector evaluation for improved situational awareness: Receiver operator characteristic curve based
Wuijckhuijse, A.L. van; Nieuwenhuizen, M.S.
2016-01-01
In military and civilian operations good situational awareness is a prerequisite to make proper decisions. The situational awareness is among others based upon intelligence, threat analysis and detection, altogether element of the so-called DIM (detection, identification, monitoring) system. In case
Zavyalov, Vladimir V.; Bingham, Gail E.; Wojcik, Michael; Hatfield, Jerry L.; Wilkerson, Thomas D.; Martin, Randal S.; Marchant, Christian; Moore, Kori; Bradford, Bill
2010-10-01
Agriculture, through wind erosion, tillage and harvest operations, burning, diesel-powered machinery and animal production operations, is a source of particulate matter emissions. Agricultural sources vary both temporally and spatially due to daily and seasonal activities and inhomogeneous area sources. Conventional point sampling methods originally designed for regional, well mixed aerosols are challenged by the disrupted wind flow and by the small mobile source of the emission encountered in this study. Atmospheric lidar (LIght Detection And Ranging) technology provides a means to derive quantitative information of particulate spatial and temporal distribution. In situ point measurements of particulate physical and chemical properties are used to characterize aerosol physical parameters and calibrate lidar data for unambiguous lidar data processing. Atmospheric profiling with scanning lidar allows estimation of temporal and 2D/3D spatial variations of mass concentration fields for different particulate fractions (PM1, PM2.5, PM10, and TSP) applicable for USEPA regulations. This study used this advanced measurement technology to map PM emissions at high spatial and temporal resolutions, allowing for accurate comparisons of the Conservation Management Practice (CMP) under test. The purpose of this field study was to determine whether and how much particulate emission differs from the conventional method of agricultural fall tillage and combined CMP operations.
Kucherenko, I S; Soldatkin, Capital O Cyrillic О; Soy, E; Kirdeciler, K; Öztürk, S; Akata, B; Jaffrezic-Renault, N; Soldatkin, A P; Dzyadevych, S V
2012-08-01
Effect of different modifications of zeolite Na(+)-BEA on working characteristics of urease-based conductometric biosensor was studied. As the biosensor sensitive elements were used bioselective membranes based on urease and various zeolites immobilised with bovine serum albumin on the surface of conductometric transducers. Influence of zeolites on sensitivity of urea biosensor was investigated as well as reproducibility of biosensor signal and reproducibility of activity of the bioselective element after different variants of urease immobilisation on the surface of conductometric transducer. The biosensors based on zeolites (NH4(+)-BEA 30 and H(+)-BEA 30) were shown to be the most sensitive. Concentration of these zeolites in the bioselective membrane was optimized. Use of zeolites modified with methyl viologen and silver was ascertained to be of no prospect for urea conductometric biosensors. It was demonstrated that characteristics of urea biosensors can be regulated, varying zeolites modifications and their concentrations in bioselective membranes.
Estimation of active force-length characteristics of human vastus lateralis muscle.
Ichinose, Y; Kawakami, Y; Ito, M; Fukunaga, T
1997-01-01
The length and angles of fascicles were determined for the vastus lateralis muscle (VL) using ultrasonography in 6 subjects performing ramp isometric knee extension. The subject increased torque from zero (relax) to maximum (MVC) with the knee positioned every 15 degrees, from 10 degrees to 100 degrees flexion (0 degrees = full extension). As the knee was positioned closer to extension, fascicle length was shorter [116 +/- 4.7 (mean +/- SEM) mm at 100 degrees vs. 88 +/- 4.1 mm at 10 degrees (relax)]. The fascicle length of the VL decreased with increasing torque at each knee position [116 +/- 4.7 (relax) to 92 +/- 4.3 mm (MVC) at 100 degrees]. On the other hand, fascicle angles increased with an increase in torque. These changes reflected the compliance of the muscle-tendon complex which increased as the knee reached a straight position. The estimated muscle force of the VL was maximal (2,052 +/- 125 N) for a fascicle length of 78 +/- 2.7 mm (i.e. optimum length) with the knee positioned at 70 degrees of flexion. The relationship between muscle force and fascicle length indicated that the VL uses the ascending (knee 70 degrees) of the force-length curve.
Directory of Open Access Journals (Sweden)
C. Ogbonna Emerole
2013-07-01
Full Text Available This study on trade enhancement Characteristics of sweet (dessert banana fruit and estimation of transaction costs was conducted in Okigwe Metropolis of Imo State, Nigeria. Stratified random sampling technique was adopted in selecting 80 respondents comprising 40 dessert banana traders (panelists and 40 dessert banana consumers. Monthly trade data was collected from the respondents using pretested semi-structured questionnaire during dry season (November-April and rain season (May-October for the year 2012. Data collected were subjected to descriptive statistical analysis; with transaction costs estimated as ex ante and ex post components. Hedonic pricing regression model was used in determining buyer socioeconomic/banana attributes that influenced willingness to pay price. Fruit characteristics that significantly enhanced trade of sweet banana in descending order were taste (3.83, fruit variety (3.57, and fruit skin colour (3.50. Other significant factors were level of ripeness (3.49, availability in off-season (3.46, fruit size (3.20 and cleanliness (3.20. Mean ex-ante transaction costs for sweet banana was N77, 800.00/trader and its mean ex-post transaction cost was N25,080.00/trader. We recommended that traders should take advantage of Global Mobile System (GSM to overcome information barriers on banana trading. Government and health institutions should intensify consumer safety education, and encourage horticultural unions to heighten postharvest monitoring of stored and displayed dessert banana fruits to enforce observance of ripening standards.
Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime
Schneider, Matthieu; Berthe, Laurent; Fabbro, Rémy; Muller, Maryse
2008-01-01
International audience; Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm−2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this ...
Abu Abeeleh, Mahmoud; Saleh, Suhayl; Alhaddad, Emad; Alsmady, Moaath; Alshehabat, Musa; Bani Ismail, Zuhair; Massad, Islam; Bani Hani, Amjad; Abu Halaweh, Sami
2017-07-01
The objectives of this retrospective study were to characterize the clinical presentation, diagnostic findings, surgical approaches, intra-operative challenges and complications following the surgical treatment of cardiac myxoma in two of the largest referral hospitals in Jordan. Medical records of all patients presented to the cardiology department during the period between 1984 and 2016 were reviewed. Criteria for inclusion in the study were: (1) patients who were presented for cardiac evaluation due to symptoms suggestive of a primary cardiac problem, (2) completed medical records, including results of echocardiography suggestive of intra-cardiac occupying mass, (3) the surgical operation was undertaken and intra-operative data was available, (4) a histological diagnosis of myxoma was available and (5) the discharge status and follow-up data were available for at least 2 years after initial surgery. A total of 27 patients fulfilled the criteria for inclusion in the study. The average age was 42 years. Thirteen of the patients were females and 14 patients were males. The most common clinical presentations were dyspnea (29.6%) and murmurs (22.2%). Non-specific signs, such as weight loss, fever, fatigue, arthralgia and anemia, were reported in 10 (37%) patients. Signs related to systemic embolization were reported in 9 (33.3%) of the patients, involving the upper and lower extremities (55.6%), brain ischemia and vision loss (54.4%). Tumors in all patients were successfully resected under cardiopulmonary bypass support. The tumor was pedunculated in 17 (62.9%) of the patients and the size of the tumors varied from 1 to 7 centimeters in diameter. The tumor was located in the left atrium in 21 patients (77.7%), in the right atrium in 4 patients (14.8%), in the right ventricular side of the septum in 1 patient (3.7%) and involving the tricuspid valve in 1 patient (3.7%). The left atrial approach was used in 3 patients, a right atrial approach in 4 patients and a bi
Use of Airborne LiDAR To Estimate Forest Stand Characteristics
Li, Qi; Zhou, Wei; Li, Chang
2014-03-01
Small-Footprint Airborne LiDAR(light detection and ranging) remote sensing is a breakthrough technology for deriving forest canopy structural characteristics. Because the technique is relatively new as applied to canopy measurement in China, there is a tremendous need for experiments that integrate field work, LiDAR remote sensing and subsequent analyses for retrieving the full complement of structural measures critical for forestry applications. Data storage capacity and high processing speed available today have made it possible to digitally sample and store the entire reflected waveform, instead of only extracting the discrete coordinates which form the so-called point clouds. Return waveforms can give more detailed insights into the vertical structure of surface objects, surface slope, roughness and reflectivity than the conventional echoes. In this paper, an improved Expectation Maximum (EM) algorithm is adopted to decompose raw waveform data. Derived forest biophysical parameters, such as vegetation height, subcanopy topography, crown volume, ground reflectivity, vegetation reflectivity and canopy closure, are able to describe the horizontal and vertical forest canopy structure.
Hayashi, Yoshihiro; Miura, Takahiro; Shimada, Takuya; Onuki, Yoshinori; Obata, Yasuko; Takayama, Kozo
2013-10-01
Tablet characteristics of tensile strength and disintegration time were predicted using residual stress distribution, simulated by the finite element method (FEM). The Drucker-Prager Cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders composed of lactose (LAC), cornstarch (CS), and microcrystalline cellulose (MCC). The DPC model was calibrated using a direct shear test and analysis of the hardening law of the powder. The constructed DPC model was fed into the analysis using the FEM, and the mechanical behavior of pharmaceutical powders during compaction was analyzed using the FEM. The results revealed that the residual stress distribution of the tablets was uniform when the compression force increased. In particular, the residual stress distribution of tablets composed of equal amounts of LAC, CS, and MCC was more uniform than the tablets composed of 67% LAC and 33% CS, with no MCC. The tensile strength and disintegration time were predicted accurately from the residual stress distribution of tablets using multiple linear regression analysis and partial least squares regression analysis. This suggests that the residual stress distribution of tablets is related closely to the tensile strength and disintegration time.
Energy Technology Data Exchange (ETDEWEB)
Kudariyawar, J.Y. [Homi Bhabha National Institue, Mumbai (India); Vaidya, A.M.; Maheshwari, K.K.; Srivastava, A.K. [Reactor Engineering Division, Bhabha Atomic Research Center, Mumbai (India); Satyamurthy, P. [ATDS, Bhabha Atomic Research Center, Mumbai (India)
2015-03-15
The steady state and transient characteristics of a molten salt natural circulation loop (NCL) are obtained by 3D CFD simulations. The working fluid is a mixture of NaNO{sub 3} and KNO{sub 3} in 60:40 ratio. Simulation is performed using PHOENICS CFD software. The computational domain is discretized by a body fitted grid generated using in-built mesh generator. The CFD model includes primary side. Primary side fluid is subjected to heat addition in heater section, heat loss to ambient (in piping connecting heater and cooler) and to secondary side (in cooler section). Reynolds Averaged Navier Stokes equations are solved along with the standard k-ε turbulence model. Validation of the model is done by comparing the computed steady state Reynolds number with that predicted by various correlations proposed previously. Transient simulations were carried out to study the flow initiations transients for different heater powers and different configurations. Similarly the ''power raising'' transient is computed and compared with in-house experimental data. It is found that, using detailed information obtained from 3D transient CFD simulations, it is possible to understand the physics of oscillatory flow patterns obtained in the loop under certain conditions.
Protective clothing for pesticide operators: part II--data analysis of fabric characteristics.
Shaw, Anugrah; Schiffelbein, Paul
2016-01-01
Development of objective measurements is an important requirement for establishing performance-based standards for protective clothing used while handling pesticide. This study, the second in a two-part series, reports on the work completed to evaluate the performance of approximately 100 fabrics that are either used or have the potential to be used for garments worn by operators while applying pesticides. Part I, published separately, provides an overview of these issues and describes research undertaken to select a test chemical for use in subsequent studies. The goals of this study were first to develop a comprehensive approach to evaluate the performance of garments currently being used by pesticide operators, and second, to use the laboratory and field data in the development of performance specifications.
Zacharias, Jaime
2016-01-01
Ultrasound activation of phacoemulsification (phaco) tips can create considerable thermal energy that may increase the risk of tissue damage during cataract surgery. The purpose of this study was to define the thermal profiles of three phaco tip designs in simulated surgical conditions. In this laboratory investigation, sleeved phaco tips (mini-flared Kelman(®) tip with aspiration bypass port and Intrepid(®) Balanced Tip with aspiration bypass port, and MST A1 bent-mini phaco tip (without aspiration bypass) were tested using an ultrasonic phaco device operated in torsional mode at power levels of 50%, 75%, and 100% amplitude. An automated fixture applied a 30 g load to simulate compression against the incision site, leading to friction between the silicone sleeve and the titanium tip. Temperature was recorded by high rate infrared imaging under conditions of free flow and occlusion, which was simulated by clamping the aspiration line. Data were summarized using descriptive statistics. Baseline temperatures of ~26°C were observed for all tips. During ultrasonic operation at 50%, 75%, and 100% amplitude, temperatures were lower for the mini-flared and balanced tips versus the bent-mini tip, both when load was applied and during occlusion. The bent-mini tip reached temperatures as high as 70°C during occlusion with load when operated at 100% amplitude, whereas the mini-flared tip remained tip remained tips, temperature increases during operation were not markedly different from free flow and no-load conditions when occlusion or frictional events were simulated. In all experiments for each tip design, increasing ultrasound power was associated with greater increases in tip temperature. Tip temperatures increased with applied load, but marked temperature increases during occlusion were observed only with the bent-mini tip. The balanced tip produced minimal thermal peaks in all tests.
Performance and Operating Characteristics of a Novel Positive-Displacement Oil-Free CO2 Compressor
Kurtulus, Orkan; YANG Bin; Lumpkin, Dominique; Eckhard A. Groll; Jestings, Lee; Conde, Ricardo
2014-01-01
Research activities towards developing CO2 compressors have increased drastically during the last couple years. Since the transcritical CO2 cycle operates at much higher absolute pressures as compared to the conventional vapor compression cycles, it is necessary to develop new compressors or modify existing ones. In this paper, a novel positive-displacement oil-free CO2 compressor will be introduced. The compressor’s mechanical linkage system will be described. In addition, preliminary compre...
Parallel Operation Characteristics Analysis of Sewage Source Heat Pump Units in Winter
Institute of Scientific and Technical Information of China (English)
庄兆意; 张承虎; 王海燕; 孙德兴
2010-01-01
Sewage source heat pump unit operates under partial load most of the time, and study on the law of coefficient of performance (COP) of the unit varying with load ratio can provide basis for the heat pump units running in high efficiency. A mathematical model determining COP, evaporation temperature and condensation temperature of a single unit was proposed. Under the condition of uniform load distribution, the model was established according to different ways of bearing partial load with the same type multi...
CIACCIO, EDWARD J.; BIVIANO, ANGELO B.; GAMBHIR, ALOK; EINSTEIN, ANDREW J.; GARAN, HASAN
2014-01-01
Background When atrial fibrillation (AF) is incessant, imaging during a prolonged ventricular RR interval may improve image quality. It was hypothesized that long RR intervals could be predicted from preceding RR values. Methods From the PhysioNet database, electrocardiogram RR intervals were obtained from 74 persistent AF patients. An RR interval lengthened by at least 250 ms beyond the immediately preceding RR interval (termed T0 and T1, respectively) was considered prolonged. A two-parameter scatterplot was used to predict the occurrence of a prolonged interval T0. The scatterplot parameters were: (1) RR variability (RRv) estimated as the average second derivative from 10 previous pairs of RR differences, T13–T2, and (2) Tm–T1, the difference between Tm, the mean from T13 to T2, and T1. For each patient, scatterplots were constructed using preliminary data from the first hour. The ranges of parameters 1 and 2 were adjusted to maximize the proportion of prolonged RR intervals within range. These constraints were used for prediction of prolonged RR in test data collected during the second hour. Results The mean prolonged event was 1.0 seconds in duration. Actual prolonged events were identified with a mean positive predictive value (PPV) of 80% in the test set. PPV was >80% in 36 of 74 patients. An average of 10.8 prolonged RR intervals per 60 minutes was correctly identified. Conclusions A method was developed to predict prolonged RR intervals using two parameters and prior statistical sampling for each patient. This or similar methodology may help improve cardiac imaging in many longstanding persistent AF patients. PMID:23998759
Institute of Scientific and Technical Information of China (English)
Jun; XU; Jianjun; JIANG
2013-01-01
With the portable Fourier Transform Infrared Spectroscopy (FTIR), the reflectance spectra of soil samples with different moisture content are measured in laboratory for expounding the characteristic of radiation in the thermal infrared part of the spectrum with different soil moisture content. A model of estimating the moisture content in soil is attempted to make based on Moisture Diagnostic Index (MDI). In general,the spectral characteristic of soil emissivity in laboratory includes the following aspects.Firstly,in the region of 8.0-9.5 μm,along with the increase of soil moisture content,the emissivity of soil increases to varying degrees. The spectral curves are parallel relatively and have a tendency to become horizontal and the absorbed characteristic of reststrahlen is also weakened relatively with the increase of soil moisture in this region.Secondly,in the region of 11.0-14.0 μm,the emissivity of soil has a tendency of increasing.There is an absorption value near about 12.7 μm. As the soil moisture content increases,the depth of absorption also increases. This phenomenon may be caused by soil moisture absorption. Methods as derivative, difference and standardized ratio transformation may weaken the background noise effectively to the spectrum data. Especially using the ratio of the emissivity to the average of 8-14 μm may obviously enhance the correlation between soil moisture and soil emissivity. According to the result of correlation analysis, the 8.237 μm is regarded as the best detecting band for soil moisture content. Moreover,based on the Moisture Diagnostic Index ( MDI) in the 8.194-8.279 μm, the logarithmic model of estimating soil moisture is made.
Song; Bolton
2000-03-01
A method for evaluating the acoustical properties of homogeneous and isotropic porous materials that may be modeled as fluids having complex properties is described here. To implement the procedure, a conventional, two-microphone standing wave tube was modified to include: a new sample holder; a section downstream of the sample holder that accommodated a second pair of microphone holders and an approximately anechoic termination. Sound-pressure measurements at two upstream and two downstream locations were then used to estimate the two-by-two transfer matrix of porous material samples. The experimental transfer matrix method has been most widely used in the past to measure the acoustical properties of silencer system components. That procedure was made more efficient here by taking advantage of the reciprocal nature of sound transmission through homogeneous and isotropic porous layers. The transfer matrix of a homogeneous and isotropic, rigid or limp porous layer can easily be used to identify the material's characteristic impedance and wave number, from which other acoustical quantities of interest can be calculated. The procedure has been used to estimate the acoustical properties of a glass fiber material: good agreement was found between the estimated acoustical properties and those predicted by using the formulas of Delany and Bazley.
Cho, Y. S.; Choi, H. S.; Jung, B. I.
2011-11-01
In a transformer-type superconducting fault current limiter (SFCL) with a neutral line, which is connected between the superconducting elements and secondary windings, we verified that the SFCL has excellent characteristics that induce the perfect simultaneous quench of the superconducting elements in the previous study. The application of the SFCL to the power networks requires its coordination with the reclosing operation duty, which protects a circuit. In this study, the fault current limiting and recovery characteristics of superconducting elements in the three-phase transformer-type SFCL with the neutral line were analyzed. The limiting rate of the fault current in the transformer-type SFCL could increased by an iron core, which allows quenching of the superconducting elements in a sound phase as well as in a faulted phase. In addition, the simultaneous quench led to uniform burdens on superconducting elements, all of which recovered their superconducting state within an opening cycle of a circuit breaker. Thus, the transformer-type SFCL with the neutral line could reliably conduct the fault current limiting and recovery operations of superconducting elements according to the reclosing operation duty and fault types.
[Simulation of air pollution characteristics and estimates of environmental capacity in Zibo City].
Xue, Wen-Bo; Wang, Jin-Nan; Yang, Jin-Tian; Lei, Yu; Yan, Li; He, Jin-Yu; Han, Bao-Ping
2013-04-01
To develop a new pattern of air pollution control that is based on the integration of "concentration control, total amount control, and quality control", and in the context of developing national (2011-2015 air pollution control plan for key areas) and (Environmental protection plan of Zibo municipality for the "12th Five-Year Plan" period), a simulation of atmospheric dispersion of air pollutants in Zibo City and its peripheral areas is carried out by employing CALPUFF model, and the atmospheric environmental capacity of SO2, NO(x) and PM10 is estimated based on the results of model simulation and using multi-objective linear programming optimization. The results indicates that the air pollution in Zibo City is significantly related to the pollution sources outside of Zibo City, which contributes to the annual average concentration of SO2, NO2 and PM10 in Zibo City by 26.34%, 21.23%, and 14.58% respectively. There is a notable interaction between districts and counties of Zibo municipality, in which the contribution of SO2, NO(x) and PM10 emissions in surrounding counties and districts to the annual average concentrations of SO2, NO2 and PM10 in downtown area are 35.96%, 43.17%, and 17.69% respectively. There is a great variation in spatial sensitivity of air pollutant emission, and the environmental impact of unit pollutant emissions from Zhoucun, Huantai, Zhangdian and Zichuan is greater than that released from other districts/counties. To meet the requirement of (Ambient air quality standard) (GB 3095-2012), the environmental capacities of SO2, NO(x) and PM10 of Zibo City are only 8.03 x 10(4) t, 19.16 x 10(4) t and 3.21 x 10(4) t, respectively. Therefore, it is imperative to implement regional air pollution joint control in Shandong peninsula in order to ensure the achievement of air quality standard in Zibo City.
Kennen, J.G.; Kauffman, L.J.; Ayers, M.A.; Wolock, D.M.; Colarullo, S.J.
2008-01-01
hydrologic instability and other anthropogenic disturbance become much less prevalent. We also found strong relations between an index of invertebrate-assemblage impairment, its component metrics, and the primary disturbance gradient. The process-oriented watershed modeling approach used in this study provides a means to evaluate how natural landscape features interact with anthropogenic factors and assess their effects on flow characteristics and stream ecology. By combining watershed modeling and indirect ordination techniques, we were able to identify components of the hydrologic regime that have a considerable effect on aquatic-assemblage structure and help in developing short- and long-term management measures that mitigate the effects of anthropogenic disturbance in stream systems.
Operational characteristics and non-inductive plasmas on NSTX-U
Mueller, Dennis
2016-10-01
Start-up and ramp-up of NSTX-U plasmas with nearly full solenoid pre-charge required higher loop voltage than on NSTX in agreement with modeling. NSTX-U has operated with a plasma current (Ip) of 0.65 MA at a toroidal field (BT) of 0.63 T for 2s in L-Mode. These plasmas allowed for the initial investigation of error field correction which found a difference between correction during Ip flattop and during ramp-up. Plasma control using feedback on the X-Point locations or the X-point height and outer strike point locations is routinely used. Because an ST does not have a single coil set that controls the inner gap, it was challenging to control the time at which the plasma diverted. A novel approach was used to trade off accuracy on the outer plasma shape to achieve a reproducible inner gap. These control tools allowed study of ELMy H-mode operation at Ip = 1 MA with boronized walls. A major long-term goal for NSTX-U is totally non-inductive operation. The plan calls for initiating the plasma with coaxial helicity injection (CHI) heatied by ECH, then current drive and heating by HHFW and NBI. CHI will be used in the new geometry to demonstrate results comparable to NSTX and provide information to inform plans to upgrade the available voltage from 1.65 to 2 kV next year. Low Ip plasmas will be used to study the dependence of current drive on neutral beam voltage and injection angle. Work Supported by U.S.D.O.E. Contract No. DE-AC02-09CH11466.
Kirillov, V F; Mironov, A I; Gadakchan, K A; Mekhova, M M; Spiridonova, V S
2010-01-01
It was shown that workers performing high-precision manufacturing operations in microelectronic industry undergo severe visual, nervous and emotional stress combined with significant locomotor load, air deionization and deozonation, bacterial contamination, and UV deficit at their workplaces. These working conditions promote development of negative changes in the visual analyzer, nervous and emotional disorders, disturbances of systemic and regional hemodynamics. Also impaired is the functional state of the upper limb neuromuscular apparatus, central nervous and cardiovascular systems. The proposed certified complex of organizational, sanitary, hygienic, physiological, ergonomic, therapeutic and preventive measures has positive influence on the working capacity of employees in microelectronic industry.
Directory of Open Access Journals (Sweden)
Zacharias J
2016-06-01
Full Text Available Jaime Zacharias Phacodynamics Laboratory, Pasteur Ophthalmic Clinic, Santiago, Chile Purpose: Ultrasound activation of phacoemulsification (phaco tips can create considerable thermal energy that may increase the risk of tissue damage during cataract surgery. The purpose of this study was to define the thermal profiles of three phaco tip designs in simulated surgical conditions. Methods: In this laboratory investigation, sleeved phaco tips (mini-flared Kelman® tip with aspiration bypass port and Intrepid® Balanced Tip with aspiration bypass port, and MST A1 bent-mini phaco tip (without aspiration bypass were tested using an ultrasonic phaco device operated in torsional mode at power levels of 50%, 75%, and 100% amplitude. An automated fixture applied a 30 g load to simulate compression against the incision site, leading to friction between the silicone sleeve and the titanium tip. Temperature was recorded by high rate infrared imaging under conditions of free flow and occlusion, which was simulated by clamping the aspiration line. Data were summarized using descriptive statistics. Results: Baseline temperatures of ~26°C were observed for all tips. During ultrasonic operation at 50%, 75%, and 100% amplitude, temperatures were lower for the mini-flared and balanced tips versus the bent-mini tip, both when load was applied and during occlusion. The bent-mini tip reached temperatures as high as 70°C during occlusion with load when operated at 100% amplitude, whereas the mini-flared tip remained <50°C, and the balanced tip remained <36°C in all test conditions. For the mini-flared and balanced tips, temperature increases during operation were not markedly different from free flow and no-load conditions when occlusion or frictional events were simulated. Conclusion: In all experiments for each tip design, increasing ultrasound power was associated with greater increases in tip temperature. Tip temperatures increased with applied load, but marked
Baidak, Y.; Smyk, V.
2017-08-01
Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.
Institute of Scientific and Technical Information of China (English)
ZHANG; Renhua; SUN; Xiaomin; WANG; Weimin; XU; Jinping; ZH
2005-01-01
Based on the improved interaction mechanism of two-layer model, this paper proposed Pixel Component Arranging and Comparing Algorithm (PCACA) and theoretically positioning algorithm, estimated the true temperature of mixed pixel in four extreme points in combination with the measurements of dry and wet points in calibration fields and improved the reliability of positioning dry and wet line. A new two-layer energy-separation algorithm was proposed,which was simple and direct without resistance network parameters for each pixel. We also proposed a new thought about the effect of advection. The albedo of mixed pixel was also separated with PCACA. In combination with two-layer energy-separation algorithm, the net radiation of mixed pixel was separated to overcome the uncertainty of conventional energy-separation algorithm using Beer's Law. Through the validation of retrieval result, this method is proved to be feasible and operational. At the same time, the uncertainty of this algorithm was objectively analyzed.
Developing a Ballistic Software Kit to Estimate Vehicle Characteristics at the Draft Design Stage
Directory of Open Access Journals (Sweden)
V. I. Maiorova
2015-01-01
similar situations happen also when using other software of the kit. So there are special logical and mathematical tricks to overcome these difficulties.The free accessible software available for the trajectory calculation is either inappropriate for solving the regarded tasks, in principle, or is functionally limited. The real analogues are available either at the rocket and space enterprises, or in research institutes, and a high cost disables their licensing use, especially, in state educational institutions. Besides, such software often falls within the restrictions on double-purpose technology circulation. In spite of the existing non-commercial analogues the developed software kit allows the transformation of the program while dealing with various tasks in new projects. This kit holds an intermediate niche between approximate estimations of vehicle’s ballistic properties at the stage of technical proposal and accurate calculations to be performed, usually, only for final version of the flying vehicle.
Hou, Xiaolin; Liu, Sitong; Feng, Ying
2017-01-01
Anammox is a cost-effective process to treat nitrogenous wastewater. In this work, excitation–emission matrix (EEM) fluorescence spectroscopy was used to characterize the intracellular and extracellular substances of anammox sludge during reactor operation of 276 days. Four main fluorophores were identified from the intracellular substances. Two main protein-like fluorophores were identified from the extracellular substances. Correlation analysis revealed that intracellular 420 peak and humic-like peak had strong correlation with nitrogen removal rate. The two intracellular protein-like peaks had high correlation with MLVSS and MLVSS growth rate. Correlation analysis between different fluorophores discovered that the two peaks in each of these three groups—two intracellular protein-like peaks, two humic acid-like peaks and the two extracellular protein-like peaks had strong intercorrelation, which gave evidence of their homology. A specific method for fluorescence monitoring of anammox reactor were put forward, which included typical fluorescence indexes and their possible values for different operation phases. PMID:28091530
Khobragade, P.; Fan, Jiahua; Rupcich, Franco; Crotty, Dominic J.; Gilat Schmidt, Taly
2016-03-01
This study quantitatively evaluated the performance of the exponential transformation of the free-response operating characteristic curve (EFROC) metric, with the Channelized Hotelling Observer (CHO) as a reference. The CHO has been used for image quality assessment of reconstruction algorithms and imaging systems and often it is applied to study the signal-location-known cases. The CHO also requires a large set of images to estimate the covariance matrix. In terms of clinical applications, this assumption and requirement may be unrealistic. The newly developed location-unknown EFROC detectability metric is estimated from the confidence scores reported by a model observer. Unlike the CHO, EFROC does not require a channelization step and is a non-parametric detectability metric. There are few quantitative studies available on application of the EFROC metric, most of which are based on simulation data. This study investigated the EFROC metric using experimental CT data. A phantom with four low contrast objects: 3mm (14 HU), 5mm (7HU), 7mm (5 HU) and 10 mm (3 HU) was scanned at dose levels ranging from 25 mAs to 270 mAs and reconstructed using filtered backprojection. The area under the curve values for CHO (AUC) and EFROC (AFE) were plotted with respect to different dose levels. The number of images required to estimate the non-parametric AFE metric was calculated for varying tasks and found to be less than the number of images required for parametric CHO estimation. The AFE metric was found to be more sensitive to changes in dose than the CHO metric. This increased sensitivity and the assumption of unknown signal location may be useful for investigating and optimizing CT imaging methods. Future work is required to validate the AFE metric against human observers.
Sepp Neves, Antonio Augusto; Pinardi, Nadia; Martins, Flavio
2016-08-01
Oil Spill Risk Assessments (OSRAs) are widely employed to support decision making regarding oil spill risks. This article adapts the ISO-compliant OSRA framework developed by Sepp Neves et al. (J Environ Manag 159:158-168, 2015) to estimate risks in a complex scenario where uncertainties related to the meteo-oceanographic conditions, where and how a spill could happen exist and the risk computation methodology is not yet well established (ensemble oil spill modeling). The improved method was applied to the Algarve coast, Portugal. Over 50,000 simulations were performed in 2 ensemble experiments to estimate the risks due to operational and accidental spill scenarios associated with maritime traffic. The level of risk was found to be important for both types of scenarios, with significant seasonal variations due to the the currents and waves variability. Higher frequency variability in the meteo-oceanographic variables were also found to contribute to the level of risk. The ensemble results show that the distribution of oil concentrations found on the coast is not Gaussian, opening up new fields of research on how to deal with oil spill risks and related uncertainties.
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Jiangong Zhu
2017-01-01
Full Text Available An impedance-based temperature estimation method is investigated considering the electrochemical non-equilibrium with short-term relaxation time for facilitating the vehicular application. Generally, sufficient relaxation time is required for battery electrochemical equilibrium before the impedance measurement. A detailed experiment is performed to investigate the regularity of the battery impedance in short-term relaxation time after switch-off current excitation, which indicates that the impedance can be measured and also has systematical decrement with the relaxation time growth. Based on the discussion of impedance variation in electrochemical perspective, as well as the monotonic relationship between impedance phase shift and battery internal temperature in the electrochemical equilibrium state, an exponential equation that accounts for both measured phase shift and relaxation time is established to correct the measuring deviation caused by electrochemical non-equilibrium. Then, a multivariate linear equation coupled with ambient temperature is derived considering the temperature gradients between the active part and battery surface. Equations stated above are all identified with the embedded thermocouple experimentally. In conclusion, the temperature estimation method can be a valuable alternative for temperature monitoring during cell operating, and serve the functionality as an efficient implementation in battery thermal management system for electric vehicles (EVs and hybrid electric vehicles (HEVs.
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Senthil Ramalingam
2014-09-01
Full Text Available This study aims to find the optimum performance and emission characteristics of single cylinder variable compression ratio (VCR engine with different blends of Annona methyl ester (AME as fuel. The performance parameters such as specific fuel consumption (SFC, brake thermal efficiency (BTE, and emission levels of HC, CO, Smoke, and NOx were compared with the diesel fuel. It is found that, at compression ratio of 17: 1 for A20 blended fuel (20% AME + 80% Diesel shows better performance and lower emission level which is very close to neat diesel fuel. The engine was operated with different values of compression ratio (15, 16, and 17 to find out best possible combination for operating engine with blends of AME. It is also found that the increase of compression ratio increases the BTE and reduces SFC and has lower emission without any engine in design modifications.
Enzymatic AND logic gates operated under conditions characteristic of biomedical applications.
Melnikov, Dmitriy; Strack, Guinevere; Zhou, Jian; Windmiller, Joshua Ray; Halámek, Jan; Bocharova, Vera; Chuang, Min-Chieh; Santhosh, Padmanabhan; Privman, Vladimir; Wang, Joseph; Katz, Evgeny
2010-09-23
Experimental and theoretical analyses of the lactate dehydrogenase and glutathione reductase based enzymatic AND logic gates in which the enzymes and their substrates serve as logic inputs are performed. These two systems are examples of the novel, previously unexplored class of biochemical logic gates that illustrate potential biomedical applications of biochemical logic. They are characterized by input concentrations at logic 0 and 1 states corresponding to normal and pathophysiological conditions. Our analysis shows that the logic gates under investigation have similar noise characteristics. Both significantly amplify random noise present in inputs; however, we establish that for realistic widths of the input noise distributions, it is still possible to differentiate between the logic 0 and 1 states of the output. This indicates that reliable detection of pathophysiological conditions is indeed possible with such enzyme logic systems.
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Alfonso Duran Heras
2008-12-01
Full Text Available The aim of this article is to establish the main characteristics of the organizations that have successfully implemented information systems based on Service Oriented Architecture (SOA. Their environmental circumstances have also been studied. To achieve this objective, a SOA bibliographic review has been carried out, encompassing an analysis of 25 real cases in which different SOA applications were successfully implemented. All these cases were published between 2.001 and 2.007. The conclusions of this article can be briefly summarized as follows: SOA is well suited for organizations that rely on important legacy systems, whose performance is hindered by the lack of integration and flexibility of their computer architectures. These organizations therefore need to improve such architectures rather than replace them by new systems; SOA is being used by organizations that need to integrate their systems with those of their supply chain partners; SOA solutions provide support for the use of Web technologies.
Sun, Wen-Ting; Li, Guo; Li, He-Ping; Bao, Cheng-Yu; Wang, Hua-Bo; Zeng, Shi; Gao, Xing; Luo, Hui-Ying
2007-06-01
Rf, atmospheric-pressure glow discharge (APGD) plasmas with bare metal electrodes have promising prospects in the fields of plasma-aided etching, thin film deposition, disinfection and sterilization, etc. In this paper, the discharge characteristics are presented for the rf APGD plasmas generated with pure argon or argon-ethanol mixture as the plasma-forming gas and using water-cooled, bare copper electrodes. The experimental results show that the breakdown voltage can be reduced significantly when a small amount of ethanol is added into argon, probably due to the fact that the Penning ionization process is involved, and a pure α-mode discharge can be produced more easily with the help of ethanol. The uniformity of the rf APGDs of pure argon or argon-ethanol mixtures using bare metallic electrodes is identified with the aid of the intensified charge coupled device images.
Finkenbiner, C. E.; Avery, W. A.; Kuzila, M.; Munoz-Arriola, F.; Franz, T. E.
2015-12-01
Currently, global trends in consumptive water-use indicate an increasing and unsustainable reliance on groundwater resources. Each year approximately 60% of water used for agriculture is wasted through inadequate water conservation, losses in distribution, and inappropriate times and rates of irrigation. Therefore, in order to coordinate a strategy to accomplish the agricultural demands of our global community we must maintain a stable global food and water trade while increasing crop yield and efficiency. This research aims to improve the operability of the recently developed and promising cosmic-ray neutron method for estimating field scale soil moisture. The sensor works by passively counting above ground low-energy neutrons which correlate to the total water in the sensor measurement volume (a sphere with radius of ~300 m and vertical soil depth of ~30 cm). Because the sensor responds to different forms of water (sources of hydrogen), estimates of background water in the mineral soil need to be accounted for in order to minimize measurement error. Here we compared field-scale estimates of soil mineral water with readily available global datasets. Using the newly compiled 1km resolution Global Soil Dataset (GSDE), we were able to investigate the correlation between soil mineral water and clay content for various soil taxonomic orders. Preliminary results suggest statistically significant linear relationships for Aridisol, Mollisol and Ultisol soil orders. Incorporation of this dataset will allow for real-time soil moisture mapping of hundreds of center-pivots using the mobile cosmic-ray probe without the need for time-consuming in-situ soil sampling. Integrating this technique into soil moisture management has the potential to increase the efficiency of irrigation water used in agriculture.
Finkenbiner, C. E.; Avery, W. A.; Franz, T. E.; Munoz-Arriola, F.; Rosolem, R.
2014-12-01
Despite its critical importance to global food security, approximately 60% of water used for agriculture is wasted each year through inadequate water conservation, losses in distribution, and inefficient irrigation. Therefore, in order to coordinate a strategy to accomplish the agricultural demands in the future we must maintain a stable global food and water trade while increasing crop yield and efficiency. This research aims to improve the operability of the novel cosmic-ray neutron method used for estimating field scale soil moisture. The sensor works by passively counting the above ground low-energy neutrons which correlates to the amount of water in the measurement volume (a circle with radius of ~300 m and vertical depth of ~30 cm). Because the sensor responds to different forms of water (sources of hydrogen), estimates of background water in the mineral soil and soil organic matter must be accounted in order to minimize measurement error. Here we compared field-scale estimates of soil mineral water and soil organic matter with readily available global datasets. Using the newly compiled 1 km resolution Global Soil Dataset (GSDE), we investigate the correlation between (1) soil mineral water and clay content and (2) in-situ soil organic material. Preliminary results of in-situ samples from forty study sites around the globe suggest the GSDE dataset has sufficiently low bias and uncertainty (~ within 0.01 g/g of water equivalent) to better isolate the soil moisture signal from the neutron count information. Incorporation of this dataset will allow for real-time soil moisture mapping of hundreds of center-pivots using the mobile cosmic-ray sensor without the need of time-consuming in-situ soil sampling. The incorporation of this novel technique for soil moisture management has the potential to increase the efficiency of irrigation water use.
Vibration and Operational Characteristics of a Composite-Steel (Hybrid) Gear
Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan
2014-01-01
Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.
Pal, P. S.; Saha, Arnab; Jayannavar, A. M.
2016-09-01
We have studied the single-particle heat engine and refrigerator driven by time-asymmetric protocol of finite duration. Our system consists of a particle in a harmonic trap with time-periodic strength that drives the particle cyclically between two baths. Each cycle consists of two isothermal steps at different temperatures and two adiabatic steps connecting them. The system works in irreversible mode of operation even in the quasistatic regime. This is indicated by finite entropy production even in the large cycle time limit. Consequently, Carnot efficiency for heat engine or Carnot coefficient of performance (COP) for refrigerators is not achievable. We further analyzed the phase diagram of heat engines and refrigerators. They are sensitive to time-asymmetry of the protocol. Phase diagram shows several interesting features, often counterintuitive. The distribution of stochastic efficiency and COP is broad and exhibits power-law tails.
Niedzielski, Tomasz; Skjøth, Carsten; Werner, Małgorzata; Spallek, Waldemar; Witek, Matylda; Sawiński, Tymoteusz; Drzeniecka-Osiadacz, Anetta; Korzystka-Muskała, Magdalena; Muskała, Piotr; Modzel, Piotr; Guzikowski, Jakub; Kryza, Maciej
2017-09-01
The objective of this paper is to empirically show that estimates of wind speed and wind direction based on measurements carried out using the Pitot tubes and GNSS receivers, mounted on consumer-grade unmanned aerial vehicles (UAVs), may accurately approximate true wind parameters. The motivation for the study is that a growing number of commercial and scientific UAV operations may soon become a new source of data on wind speed and wind direction, with unprecedented spatial and temporal resolution. The feasibility study was carried out within an isolated mountain meadow of Polana Izerska located in the Izera Mountains (SW Poland) during an experiment which aimed to compare wind characteristics measured by several instruments: three UAVs (swinglet CAM, eBee, Maja) equipped with the Pitot tubes and GNSS receivers, wind speed and direction meters mounted at 2.5 and 10 m (mast), conventional weather station and vertical sodar. The three UAVs performed seven missions along spiral-like trajectories, most reaching 130 m above take-off location. The estimates of wind speed and wind direction were found to agree between UAVs. The time series of wind speed measured at 10 m were extrapolated to flight altitudes recorded at a given time so that a comparison was made feasible. It was found that the wind speed estimates provided by the UAVs on a basis of the Pitot tube/GNSS data are in agreement with measurements carried out using dedicated meteorological instruments. The discrepancies were recorded in the first and last phases of UAV flights.
Nagasawa, Sh
2017-02-01
Paperboards are recognized to be important raw materials for packaging industry due to their advantages such as high strength-to-weight ratio, recyclability. Regarding the development of advanced packaging materials and the requirement of smart formed products, a study of sheet’s response behaviour is necessary for expanding the advanced converting industry. After introducing a couple of past research works concerned crease technologies, a fundamental mechanisms of crease deformation is reviewed using the scoring depth and the folding angle of a paperboard. Since one of important forming characteristics is a time-dependent stress relaxation or time-delayed strain during a fold/unfold process, the author’s experimental approaches for estimating a short term (less than 10 seconds) dynamic deformation behaviour of creased paperboard are discussed.
Energy Technology Data Exchange (ETDEWEB)
Ye, Hong; Wang, Kai; Zhao, Xiaofeng; Chen, Feng; Li, Xuanqi; Pan, Lingyang [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, Fujian 361021 (China)
2011-01-15
Carbon emitted from urban metabolism constitutes a substantial proportion of the anthropogenic greenhouse gas emission, which is at least partially responsible for the recent global warming. Part of the urban carbon emission comes from residential energy consumption. Given the ongoing rapid urbanization and strict emission-reduction requirement, understanding the urban home energy usage carbon emission (UHEUCE) is of great importance to optimize the sustainability of social and economic developments in China. For this reason, a survey has been conducted to exam the condition of home energy usage in Xiamen Island, SE China. This study was based on 340 valid responses and a general linear model for univariate method. The analysis showed (1) among the residential building characteristics, window thermal insulation has the greatest effect on UHEUCE. (2) Construction age and wall thermal insulation could also influence UHEUCE in areas where summer is hot and winter is warm. The better heat prohibiting effect of external wall and window, as well as the newer construction, the more UHEUCE can be generated. The survey provided helpful first-hand data for design and planning on urban energy saving, emission reduction, and for relevant scientific researches. (author)
Directory of Open Access Journals (Sweden)
K. Rajagopal
2011-12-01
Full Text Available An experimental analysis was done using a four-stroke, single cylinder, constant speed, water-cooled diesel engine, which was interfaced with Engine software. Performance and emission characteristics were evaluated for three non-edible vegetable oils, i.e. thumba, jojoba, neem oil, as well as jojoba methyl ester, to study the effect of injection pressure at 205, 220, 240 and 260 bar with a variation in injection timing at 23°bTDC and 28°bTDC. The performance of jojoba methyl ester improved with an increase in injection pressure. A maximum brake thermal efficiency of 29.72% was obtained with lower emissions compared to the other vegetable oils; this might be explained by low viscosity and better combustion. Further investigations were carried out with a new lubricant, SAE 5W-30, which improved the performance of the CI engine by 1.59%. All of the abovementioned investigations were fruitful and these results are expected to lead to substantial contributions in the development of a viable vegetable oil engine.
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Mustafa Atakan Akar
2016-02-01
Full Text Available In this study, fuel properties, engine performance, and emission characteristics of diesel fuel, false flax biodiesel, and their blends with butanol have been evaluated. Blend ratios used in this study were diesel–biodiesel–butanol (70% diesel–20% biodiesel–10% butanol and 60% diesel–20% biodiesel–20% butanol by volume and biodiesel–diesel (20% biodiesel–80% diesel and 100% biodiesel by volume. Experiments showed that 10% alcohol addition to diesel and biodiesel fuels caused a decrease in torque value up to 8.57%. When butanol ratio raised to 20%, torque value decreased to an average of 12.7% and power values decreased to an average of 13.57%. Specific fuel consumption increased to an average of 10.63% and 12.80% with 10% and 20% butanol addition, respectively. Alcohol addiction into conventional diesel and biodiesel fuel slightly increased NOX emissions. Supplement of alcohol decreased CO and CO2 emissions when it was entrained to diesel and increased it when it was added to biodiesel. It means that addition of alcohol to diesel changed CO and CO2 emissions.
Energy Technology Data Exchange (ETDEWEB)
Cho, Yong-Hun [School of Advanced Materials Engineering, Kookmin University, 861-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Yoo, Sung Jong [Fuel Cell Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Park, In-Su; Jeon, Tae-Yeol; Cho, Yoon-Hwan; Lim, Ju Wan [World Class University (WCU) program of Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, College of Engineering, Seoul National University (SNU), Seoul (Korea, Republic of); Kwon, Oh Joong [Department of Energy and Chemical Engineering, University of Incheon, 12-1 Songdo-dong, Yeonsu-gu, Incheon 406-772 (Korea, Republic of); Yoon, Won-Sub [School of Advanced Materials Engineering, Kookmin University, 861-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Sung, Yung-Eun, E-mail: ysung@snu.ac.k [World Class University (WCU) program of Chemical Convergence for Energy and Environment, School of Chemical and Biological Engineering, College of Engineering, Seoul National University (SNU), Seoul (Korea, Republic of)
2010-12-30
The degradation behavior of a membrane-electrode assembly (MEA) was investigated in accelerated degradation tests under constant voltage (0.8 V and 0.7 V) and load cycling (from open circuit voltage to 0.35 V) conditions. Changes in the structural and electrochemical characteristics of MEA after the durability tests give information as to the degradation mechanism of MEAs. The results of cyclic voltammogram and postmortem analysis by X-ray diffraction and high resolution-transmission electron microscopy indicate that the cathode catalyst layers of the MEAs showed no extreme degradation under constant voltage mode, whereas MEAs under repetition of load cycling mode showed very severe degradation after 280 h. However, the single cell performance of the MEA under repetition of load cycling mode was higher than under constant voltage mode. In addition, although the Pt band in the membrane of the MEA under repetition of load cycling mode was observed by field emission scanning electron microscopy, it did not affect the ohmic resistance.
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Miroslav Kališnik
2011-05-01
Full Text Available In the introduction the evolution of methods for numerical density estimation of particles is presented shortly. Three pairs of methods have been analysed and compared: (1 classical methods for particles counting in thin and thick sections, (2 original and modified differential counting methods and (3 physical and optical disector methods. Metric characteristics such as accuracy, efficiency, robustness, and feasibility of methods have been estimated and compared. Logical, geometrical and mathematical analysis as well as computer simulations have been applied. In computer simulations a model of randomly distributed equal spheres with maximal contrast against surroundings has been used. According to our computer simulation all methods give accurate results provided that the sample is representative and sufficiently large. However, there are differences in their efficiency, robustness and feasibility. Efficiency and robustness increase with increasing slice thickness in all three pairs of methods. Robustness is superior in both differential and both disector methods compared to both classical methods. Feasibility can be judged according to the additional equipment as well as to the histotechnical and counting procedures necessary for performing individual counting methods. However, it is evident that not all practical problems can efficiently be solved with models.
Shi, Lei; Liu, Xiaowei; He, Guoqiang; Qin, Fei; Wei, Xianggeng; Yang, Bin; Liu, Jie
2016-10-01
A ready-made central strut-based rocket-based combined-cycle (RBCC) engine was numerically investigated in the ejector mode. The flow features in the RBCC inlet and the matching characteristics between the inlet and the embedded rocket during different flight regimes were examined in detail. It was necessary to perform integrated numerical simulations in the ejector mode within considerable pressure far fields around the inlet/exhaust system. The observed flow features and operation characteristics in the RBCC inlet were strongly correlated with the flight conditions, inlet configuration, and operation of the embedded rocket. It was further found that the integrated function status of multiple factors significantly influenced the performance of the RBCC engine in the ejector mode. The two parameters that macroscopically affected the performance most were the air entrainment mass and the drag of the RBCC inlet. To improve these parameters, it is vital to employ an appropriate design of the RBCC inlet and establish the optimal flight trajectory of the flight vehicle.
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G. Paterakis
2013-01-01
Full Text Available The work presents comparisons of the flame stabilization characteristics of axisymmetric disk and 2D slender bluff-body burner configurations, operating with inlet mixture stratification, under ultralean conditions. A double cavity propane air premixer formed along three concentric disks, supplied with a radial equivalence ratio gradient the afterbody disk recirculation, where the first flame configuration is stabilized. Planar fuel injection along the center plane of the leading face of a slender square cylinder against the approach cross-flow results in a stratified flame configuration stabilized alongside the wake formation region in the second setup. Measurements of velocities, temperatures, OH∗ and CH∗ chemiluminescence, local extinction criteria, and large-eddy simulations are employed to examine a range of ultralean and close to extinction flame conditions. The variations of the reacting front disposition within these diverse reacting wake topologies, the effect of the successive suppression of heat release on the near flame region characteristics, and the reemergence of large-scale vortical activity on approach to lean blowoff (LBO are investigated. The cross-correlation of the performance of these two popular flame holders that are at the opposite ends of current applications might offer helpful insights into more effective control measures for expanding the operational margin of a wider range of stabilization configurations.
Characteristics and quality of intra-operative cell salvage in paediatric scoliosis surgery.
Perez-Ferrer, A; Gredilla-Díaz, E; de Vicente-Sánchez, J; Navarro-Suay, R; Gilsanz-Rodríguez, F
2016-02-01
To determine the haematological and microbiological characteristics of blood recovered by using a cell saver with a rigid centrifuge bowl (100ml) in paediatric scoliosis surgery and to determine whether it conforms to the standard expected in adult patients. A cross-sectional, descriptive cohort study was performed on 24 consecutive red blood cell (RBC) units recovered from the surgical field and processed by a Haemolite® 2+ (Haemonetics Corp., Braintree, MA, EE. UU.) cell saver. Data were collected regarding age, weight, surgical approach (anterior or posterior), processed shed volume and volume of autologous RBC recovered, full blood count, and blood culture obtained from the RBC concentrate, and incidence of fever after reinfusion. The processed shed volume was very low (939±569ml) with high variability (coefficient of variation=0.6), unlike the recovered volume 129±50ml (coefficient of variation=0.38). A statistically significant correlation between the processed shed volume and recovered RBC concentrate haematocrit was found (Pearson, r=.659, P=.001). Haematological parameters in the recovered concentrate were: Hb 11±5.3g dl(-1); haematocrit: 32.1±15.4% (lower than expected); white cells 5.34±4.22×103 ul(-)1; platelets 37.88±23.5×103 ul(-1) (mean±SD). Blood culture was positive in the RBC concentrate recovered in 13 cases (54.2%) in which Staphylococcus coagulase (-) was isolated. Cell salvage machines with rigid centrifuge bowls (including paediatric small volume) do not obtain the expected haematocrit if low volumes are processed, and therefore they are not the best choice in paediatric surgery. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.
Shiraishi, Junji; Pesce, Lorenzo L.; Metz, Charles E.; Doi, Kunio
2009-01-01
Purpose: To provide a broad perspective concerning the recent use of receiver operating characteristic (ROC) analysis in medical imaging by reviewing ROC studies published in Radiology between 1997 and 2006 for experimental design, imaging modality, medical condition, and ROC paradigm. Materials and Methods: Two hundred ninety-five studies were obtained by conducting a literature search with PubMed with two criteria: publication in Radiology between 1997 and 2006 and occurrence of the phrase “receiver operating characteristic.” Studies returned by the query that were not diagnostic imaging procedure performance evaluations were excluded. Characteristics of the remaining studies were tabulated. Results: Two hundred thirty-three (79.0%) of the 295 studies reported findings based on observers' diagnostic judgments or objective measurements. Forty-three (14.6%) did not include human observers, with most of these reporting an evaluation of a computer-aided diagnosis system or functional data obtained with computed tomography (CT) or magnetic resonance (MR) imaging. The remaining 19 (6.4%) studies were classified as reviews or meta-analyses and were excluded from our subsequent analysis. Among the various imaging modalities, MR imaging (46.0%) and CT (25.7%) were investigated most frequently. Approximately 60% (144 of 233) of ROC studies with human observers published in Radiology included three or fewer observers. Conclusion: ROC analysis is widely used in radiologic research, confirming its fundamental role in assessing diagnostic performance. However, the ROC studies reported in Radiology were not always adequate to support clear and clinically relevant conclusions. © RSNA, 2009 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2533081632/-/DC1 PMID:19864510
Aljbour, Salah H; Kawamoto, Katsuya
2013-01-01
The present study was conducted within the framework of R&D activities on the development of gasification and reforming technologies for energy and chemical recovery from biomass resources. Gasification of the Japanese cedar wood has been investigated under various operating conditions in a bench-scale externally heated updraft gasifier; this was followed by thermal reforming. Parametric tests by varying the residence times, gasification temperatures, equivalence ratios (ERs) and steam-to-carbon (S/C) ratios were performed to determine their effects on the product gas characteristics. Thermodynamic equilibrium calculations were preformed to predict the equilibrium gas composition and compared with the experimental value. We found that the product gas characteristics in terms of the H(2)/CO ratio, CO(2)/CO ratio, and CH(4) and lighter hydrocarbons concentrations are significantly affected by the operating conditions used. Increasing the residence time decreased the CO(2)/CO ratio; however, a nominal effect was noticed on H(2) concentration as a function of the residence time. At sufficient residence time, increasing the temperature led to higher H(2) yields, CO efficiency and higher heating value (HHV) of the product gas. The presence of steam during gasification effectively enhanced the proportion of H(2) in the product gas. However, higher S/C ratio reduced the HHV of the product gas. Increasing the ER from 0 to 0.3 increased the H(2) yields and CO efficiency and decreased the HHV of the product gas. The evolution of CH(4) and lighter hydrocarbons at low gasification temperatures was relatively higher than that at high temperature gasification. The evolution of CH(4) and lighter hydrocarbons at high gasification temperatures hardly varied over the investigated operating conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.
Operating characteristics of a 60 cm and a 10 cm electric arc-driven shock-tube
Sharma, Surendra P.; Park, Chul; Dannenberg, Robert E.
1988-01-01
This paper describes the current status of the operating characteristics of the electric arc-driven shock-tube facility at Ames Research Center, focusing on its potential usefulness in the current and anticipated future applications. The paper specifically addresses the questions as to: (1) how well the behavior of the arc driver is understood and controlled, (2) how well the facility is equipped to test low-density, very-high-velocity nonequilibrium flow regimes, and (3) how closely the facility is expected to produce an equilibrium hypersonic flow when operated in shock-tunnel modes. For these issues, it is shown that: (1) a plasma kinetics model of the exploding wire closely describes the arc behavior in the driver, (2) the facility can produce a spectroscopically-clean flow in a low density regime with a shock velocity of 13 km/sec in air when used with an aluminum driven tube, and (3) when operated as a shock-tunnel, the high enthalpy flow in the test section is expected to deviate only slightly from the perfect equilibrium flow conditions at enthalpies corresponding to flight speeds of 5 km/sec or less.
Energy Technology Data Exchange (ETDEWEB)
Banapurmath, N.R.; Tewari, P.G. [Department of Mechanical Engineering, B.V.B. College of Engineering and Technology, Vidyanagar, Poona-Bangalore Road, Hubli 580031 (India); Hosmath, R.S. [Department of Mechanical Engineering, K.L.E' s C.E.T., Belgaum (India)
2008-09-15
The high viscosity of vegetable oils leads to problem in pumping and spray characteristics. The inefficient mixing of vegetable oils with air contributes to incomplete combustion. The best way to use vegetable oils as fuel in compression ignition (CI) engines is to convert it into biodiesel. Biodiesel is a methyl or ethyl ester of fatty acids made from vegetable oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Pongamia pinnata (Honge oil), Jatropha curcas (Ratanjyot), Hevea brasiliensis (Rubber) and Calophyllum inophyllum (Nagchampa). Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in CI engines with very little or no engine modifications. This is because it has properties similar to mineral diesel. This paper presents the results of investigations carried out on a single-cylinder, four-stroke, direct-injection, CI engine operated with methyl esters of Honge oil, Jatropha oil and sesame oil. Comparative measures of brake thermal efficiency, smoke opacity, HC, CO, NO{sub X}, ignition delay, combustion duration and heat release rates have been presented and discussed. Engine performance in terms of higher brake thermal efficiency and lower emissions (HC, CO, NO{sub X}) with sesame oil methyl ester operation was observed compared to methyl esters of Honge and Jatropha oil operation. (author)
Energy Technology Data Exchange (ETDEWEB)
Miller, C.W.; Sjoreen, A.L.; Begovich, C.L.; Hermann, O.W.
1986-11-01
This code estimates concentrations in air and ground deposition rates for Atmospheric Nuclides Emitted from Multiple Operating Sources. ANEMOS is one component of an integrated Computerized Radiological Risk Investigation System (CRRIS) developed for the US Environmental Protection Agency (EPA) for use in performing radiological assessments and in developing radiation standards. The concentrations and deposition rates calculated by ANEMOS are used in subsequent portions of the CRRIS for estimating doses and risks to man. The calculations made in ANEMOS are based on the use of a straight-line Gaussian plume atmospheric dispersion model with both dry and wet deposition parameter options. The code will accommodate a ground-level or elevated point and area source or windblown source. Adjustments may be made during the calculations for surface roughness, building wake effects, terrain height, wind speed at the height of release, the variation in plume rise as a function of downwind distance, and the in-growth and decay of daughter products in the plume as it travels downwind. ANEMOS can also accommodate multiple particle sizes and clearance classes, and it may be used to calculate the dose from a finite plume of gamma-ray-emitting radionuclides passing overhead. The output of this code is presented for 16 sectors of a circular grid. ANEMOS can calculate both the sector-average concentrations and deposition rates at a given set of downwind distances in each sector and the average of these quantities over an area within each sector bounded by two successive downwind distances. ANEMOS is designed to be used primarily for continuous, long-term radionuclide releases. This report describes the models used in the code, their computer implementation, the uncertainty associated with their use, and the use of ANEMOS in conjunction with other codes in the CRRIS. A listing of the code is included in Appendix C.
O'Neill, Liam; Dexter, Franklin
2007-02-01
Data envelopment analysis (DEA) is an established technique that hospitals and anesthesia groups can use to understand their potential to grow different specialties of inpatient surgery. Often related decisions such as recruitment of new physicians are made promptly. A practical challenge in using DEA in practice for this application has been the time to obtain access to and preprocess discharge data from states. A case study is presented to show how results of DEA are linked to financial analysis for purposes of deciding which surgical specialties should be provided more resources and institutional support, including the allocation of additional operating room (OR) block time on a tactical (1 yr) time course. State discharge abstract databases were used to study how to perform and present the DEA using data from websites of the United States' (US) Healthcare Cost and Utilization Project (HCUPNet) and Census Bureau (American FactFinder). DEA was performed without state discharge data by using census data with federal surgical rates adjusted for age and gender. Validity was assessed based on multiple criteria, including: satisfaction of statistical assumptions, face validity of results for hospitals, differentiation between efficient and inefficient hospitals on other measures of how much surgery is done, and correlation of estimates of each hospital's potential to grow the workload of each of eight specialties with estimates obtained using unrelated statistical methods. A hospital can choose specialties to target for expanded OR capacity based on its financial data, its caseloads for specific specialties, the caseloads from hospitals previously examined, and surgical rates from federal census data.
Estimation of hysteretic losses for MgB2 tapes under the operating conditions of a generator
Vargas-Llanos, Carlos Roberto; Zermeño, Víctor M. R.; Sanz, Santiago; Trillaud, Frederic; Grilli, Francesco
2016-03-01
Hysteretic losses in the MgB2 wound superconducting coils of a 550 kW synchronous hybrid scaled generator were estimated as part of the European project SUPRAPOWER led by the Spanish Fundación Tecnalia Research & Innovation. Particular interest was given to the losses caused by the magnetic flux ripples in the rotor coils originating from the conventional stator during nominal operation. To compute these losses, a 2D finite element analysis was conducted and Maxwell’s equations written in the H-formulation were solved considering the nonlinear material properties of the conductor materials. The modeled tapes are made of multiple MgB2 filaments embedded in a Ni matrix and soldered to a high purity copper strip and insulated with Dacron braid. Three geometrical models of single tape cross sections of decreasing complexity were studied: (1) the first model reproduced closely the actual cross section obtained from tape micrographs. (2) The second model was obtained from the computed elasto-plastic deformation of a round Ni wire. (3) The third model was based on a simplified cross section with the superconducting filaments bundled in a single elliptical bulky structure. The last geometry allowed the validation of the modeling technique by comparing numerical losses with results from well-established analytical expressions. Additionally, the following cases of filament transpositions of the multi-filamentary tape were studied: no transposition, partial and full transposition; thereby improving understanding of the relevance of the tape fabrication process on the magnitude of the determination of ac losses. Finally, choosing the right level of geometrical detail, the following operational regimes of the machine and its impact on individual superconducting tape losses in the rotor were studied: bias-dc current, ramping current under ramping background field and magnetic flux ripples under dc background current and field.
Herman, Daniel A.; Soulas, George C.; Patterson, Michael J.
2009-01-01
The NASA s Evolutionary Xenon Thruster (NEXT) program is developing the next-generation ion propulsion system with significant enhancements beyond the state-of-the-art. The NEXT ion propulsion system provides improved mission capabilities for future NASA science missions to enhance and enable Discovery, New Frontiers, and Flagship-type NASA missions. As part of a comprehensive thruster service life assessment utilizing both testing and analyses, a Long-Duration Test (LDT) was initiated to validate and qualify the NEXT propellant throughput capability to a qualification-level of 450 kg, 1.5 times the mission-derived throughput requirement of 300 kg. This wear test is being conducted with a modified, flight-representative NEXT engineering model ion thruster, designated EM3. As of June 25, 2008, the thruster has accumulated 16,550 h of operation: the first 13,042 h at the thruster full-input-power of 6.9 kW with 3.52 A beam current and 1800 V beam power supply voltage. Operation since 13,042 h, i.e., the most recent 3,508 h, has been at an input power of 4.7 kW with 3.52 A beam current and 1180 V beam power supply voltage. The thruster has processed 337 kg of xenon (Xe) surpassing the NSTAR propellant throughput demonstrated during the extended life testing of the Deep Space 1 flight spare. The NEXT LDT has demonstrated a total impulse of 13.3 106 N s; the highest total impulse ever demonstrated by an ion thruster. Thruster plume diagnostics and erosion measurements are obtained periodically over the entire NEXT throttle table with input power ranging 0.5 to 6.9 kW. Observed thruster component erosion rates are consistent with predictions and the thruster service life assessment. There have not been any observed anomalous erosion and all erosion estimates indicate a thruster throughput capability that exceeds 750 kg of Xe, an equivalent of 36,500 h of continuous operation at the full-power operating condition. This paper presents the erosion measurements and plume
Directory of Open Access Journals (Sweden)
Darci Alberto Gatto
2010-12-01
Full Text Available Knowledge of the demarcation of juvenile and mature wood is essential both for wood technology and forest management. Thinning, in most cases, must take into account this parameter, as the juvenile wood has inferior characteristics compared to mature wood, and different proportions of each type of wood will affect the quality and the use of the wood. Thus, this study aimed to determine the age of maturation of the wood using anatomical characteristics of Carya illinoinensis (Wangenh K. Koch wood, through the segregation of juvenile and mature wood. Three adult trees, of good trunk, with diameter greater than 30 cm DBH, were chosen from the region Encosta Superior do Nordeste in the State of the Rio Grande do Sul. From each tree, one disc was removed, with approximately 2 cm in thickness, at 0.10 m in height of the trunk. From each disc was removed a central portion of 2 cm in width, well oriented in the radial direction, including the pith in the center, and this central portion was divided into samples “A” and “B”. One of these two samples was selected for separation of the initial wood of each growth ring for maceration (Jeffrey method . First, the length, width and diameter of the lumen of one hundred fibers were measured in the first ring (next to the bark and later, thirty fibers were defined per growth ring as statistically sufficient for the assay. The thickness of the walls of the fiber was taken as the half of the difference of the diameter of the fiber and the lumen. The segregation of the two types of wood was defined by the radial variation (pith-bark of the anatomical characteristics (length, diameter, width of the lumen and thickness of the wall of fibers, through two simple linear regressions. The results indicate that the fiber length is the best characteristic for the definition of the year of segregation. The age of segregation of juvenile-mature wood was defined as 16 years. In their turn, the anatomical parameters
Taylor, Thomas E.; L'Ecuyer, Tristan; Slusser, James; Stephens, Graeme; Krotkov, Nick; Davis, John; Goering, Christian
2005-08-01
Extensive sensitivity and error characteristics of a recently developed optimal estimation retrieval algorithm which simultaneously determines aerosol optical depth (AOD), aerosol single scatter albedo (SSA) and total ozone column (TOC) from ultra-violet irradiances are described. The algorithm inverts measured diffuse and direct irradiances at 7 channels in the UV spectral range obtained from the United States Department of Agriculture's (USDA) UV-B Monitoring and Research Program's (UVMRP) network of 33 ground-based UV-MFRSR instruments to produce aerosol optical properties and TOC at all seven wavelengths. Sensitivity studies of the Tropospheric Ultra-violet/Visible (TUV) radiative transfer model performed for various operating modes (Delta-Eddington versus n-stream Discrete Ordinate) over domains of AOD, SSA, TOC, asymmetry parameter and surface albedo show that the solutions are well constrained. Realistic input error budgets and diagnostic and error outputs from the retrieval are analyzed to demonstrate the atmospheric conditions under which the retrieval provides useful and significant results. After optimizing the algorithm for the USDA site in Panther Junction, Texas the retrieval algorithm was run on a cloud screened set of irradiance measurements for the month of May 2003. Comparisons to independently derived AOD's are favorable with root mean square (RMS) differences of about 3% to 7% at 300nm and less than 1% at 368nm, on May 12 and 22, 2003. This retrieval method will be used to build an aerosol climatology and provide ground-truthing of satellite measurements by running it operationally on the USDA UV network database.
Barthélémy, S.; Ricci, S.; Rochoux, M. C.; Le Pape, E.; Thual, O.
2017-09-01
This study presents the implementation and the merits of an Ensemble Kalman Filter (EnKF) algorithm with an inflation procedure on the 1D shallow water model MASCARET in the framework of operational flood forecasting on the ;Adour Maritime; river (South West France). In situ water level observations are sequentially assimilated to correct both water level and discharge. The stochastic estimation of the background error statistics is achieved over an ensemble of MASCARET integrations with perturbed hydrological boundary conditions. It is shown that the geometric characteristics of the network as well as the hydrological forcings and their temporal variability have a significant impact on the shape of the univariate (water level) and multivariate (water level and discharge) background error covariance functions and thus on the EnKF analysis. The performance of the EnKF algorithm is examined for observing system simulation experiments as well as for a set of eight real flood events (2009-2014). The quality of the ensemble is deemed satisfactory as long as the forecast lead time remains under the transfer time of the network, when perfect hydrological forcings are considered. Results demonstrate that the simulated hydraulic state variables can be improved over the entire network, even where no data are available, with a limited ensemble size and thus a computational cost compatible with operational constraints. The improvement in the water level Root-Mean-Square Error obtained with the EnKF reaches up to 88% at the analysis time and 40% at a 4-h forecast lead time compared to the standalone model.
Proposal to extend the compliance date for the Toxicity Characteristic until January 25, 1993 for produced groundwater from free phase hydrocarbon recovery operations at certain petroleum industry sites-namely, refineries, marketing terminals, bulk plants.
Directory of Open Access Journals (Sweden)
Susie Brown
Full Text Available Fisheries bycatch is a key threat to cetacean species globally. Managing the impact requires an understanding of the conditions under which animals are caught and the sections of the population affected. We used observer data collected on an albacore tuna gillnet fishery in the northeast Atlantic, to assess operational and environmental factors contributing to bycatch of common and striped dolphins, using generalised linear models and model averaging. Life history demographics of the captured animals were also investigated. In both species, young males dominated the catch. The age ratio of common dolphins was significantly different from that estimated for the population in the region, based on life tables (G = 17.1, d.f. = 2, p = 0.002. Skewed age and sex ratios may reflect varying vulnerability to capture, through differences in behaviour or segregation in populations. Adult females constituted the second largest portion of the bycatch for both species, with potential consequences for population sustainability. Depth was the most important parameter influencing bycatch of both species and reflected what is known about common and striped dolphin habitat use in the region as the probability of catching common dolphins decreased, and striped dolphins increased, with increasing depth. Striped dolphin capture was similarly influenced by the extent to which operations were conducted in daylight, with the probability of capture increasing with increased operations in the pre-sunset and post-sunrise period, potentially driven by increased ability of observers to record animals during daylight operations, or by diurnal movements increasing contact with the fishery. Effort, based on net length and soak time, had little influence on the probability of capturing either species. Our results illustrate the importance of assessing the demographic of the animals captured during observer programmes and, perhaps more importantly, suggest that effort
Directory of Open Access Journals (Sweden)
Mohamed Heikal
2013-12-01
Full Text Available The aim of the present work is to evaluate the effect of nano-silica (NS on physico-chemical, compressive and flexural strengths of OPC-granulated slag blended cement pastes and mortars. Different mixes were made with various amounts of NS, OPC and granulated blast-furnace slag (GBFS and hydrated for 3, 7, 28 and 90 days. The hydration behavior was followed by estimation of free lime (FL and combined water content at different curing ages. The required water for standard consistency, setting times and compressive strength was also determined. The results obtained were confirmed by XRD, DTA, IR and SEM techniques. The required water for standard consistency and setting times increases with NS content due to the presence of 1% of superplasticizer. As the NS content increases the values of both FL and pH decrease. The compressive and flexural strengths of cement mortars containing NS are higher than those of control OPC–GBFS mix (M3. As the NS content increases above 4 mass% NS, compressive and flexural strengths of OPC–GBFS–NS blends decrease but still more than those of the control samples (M3. The results of XRD, DSC, IR and SEM examinations are in good harmony with each other and with chemical analyses. The composite OPC–GBFS–NS cements containing 45 mass% of GBFS and 3–4 mass% of NS possess the highest improvement of mechanical properties, hydration kinetics and microstructure of hardened cement pastes and mortars.
Abdol-Hamid, Khaled S.; Ghaffari, Farhad
2011-01-01
Numerical predictions of the longitudinal aerodynamic characteristics for the Ares I class of vehicles, along with the associated error estimate derived from an iterative convergence grid refinement, are presented. Computational results are based on the unstructured grid, Reynolds-averaged Navier-Stokes flow solver USM3D, with an assumption that the flow is fully turbulent over the entire vehicle. This effort was designed to complement the prior computational activities conducted over the past five years in support of the Ares I Project with the emphasis on the vehicle s last design cycle designated as the A106 configuration. Due to a lack of flight data for this particular design s outer mold line, the initial vehicle s aerodynamic predictions and the associated error estimates were first assessed and validated against the available experimental data at representative wind tunnel flow conditions pertinent to the ascent phase of the trajectory without including any propulsion effects. Subsequently, the established procedures were then applied to obtain the longitudinal aerodynamic predictions at the selected flight flow conditions. Sample computed results and the correlations with the experimental measurements are presented. In addition, the present analysis includes the relevant data to highlight the balance between the prediction accuracy against the grid size and, thus, the corresponding computer resource requirements for the computations at both wind tunnel and flight flow conditions. NOTE: Some details have been removed from selected plots and figures in compliance with the sensitive but unclassified (SBU) restrictions. However, the content still conveys the merits of the technical approach and the relevant results.
Directory of Open Access Journals (Sweden)
P. T. Ghazvinei
2015-10-01
Full Text Available Soil erosion is undesirable natural event that causes land degradation and desertification. Identify the erosion-prone areas is a major component of preventive measures. Recent landslide damages at different regions lead us to develop a model of the erosion susceptibility map using empirical method (RUSLE. A landslide-location map was established by interpreting satellite image. Field observation data was used to validate the intensity of soil erosion. Further, a correlation analysis was conducted to investigate the "Receiver Operating Characteristic" and frequency ratio. Results showed a satisfactory correlation between the prepared RUSLE-based soil erosion map and actual landslide distribution. The proposed model can effectively predict the landslide events in soil-erosion area. Such a reliable predictive model is an effective management facility for the regional landslide forecasting system.
Vránová, J; Horák, J; Krátká, K; Hendrichová, M; Kovaírková, K
2009-01-01
An overview of the use of Receiver Operating Characteristic (ROC) analysis within medicine is provided. A survey of the theory behind the analysis is offered together with a presentation on how to create a ROC curve and how to use Cost--Benefit analysis to determine the optimal cut-off point or threshold. The use of ROC analysis is exemplified in the "Cost--Benefit analysis" section of the paper. In these examples, it can be seen that the determination of the optimal cut-off point is mainly influenced by the prevalence and the severity of the disease, by the risks and adverse events of treatment or the diagnostic testing, by the overall costs of treating true and false positives (TP and FP), and by the risk of deficient or non-treatment of false negative (FN) cases.
Sokolova, Z. N.; Pikhtin, N. A.; Tarasov, I. S.; Asryan, L. V.
2016-08-01
A model for calculating the operating characteristics of semiconductor quantum well (QW) lasers is presented. The model exploits the condition of global electroneutrality, which includes the charge carriers both in the two-dimensional (2D) active region (QW) and bulk waveguide region (optical confinement layer - OCL). The charge of each sign in the OCL is shown to be significantly larger than that in the QW. As a result of this, (i) the global electroneutrality condition reduces to the condition of electroneutrality in the OCL and (ii) the local electroneutrality in the QW can be strongly violated, i.e., the 2D electron and hole densities in the QW can significantly differ from each other.
Thurner, S; Lowen, S B; Teich, M C; Thurner, Stefan; Feurstein, Markus C.; Lowen, Steven B.; Teich, Malvin C.
1998-01-01
Receiver-operating-characteristic (ROC) analysis was used to assess the suitability of various heart rate variability (HRV) measures for correctly classifying electrocardiogram records of varying lengths as normal or revealing the presence of heart failure. Scale-dependent HRV measures were found to be substantially superior to scale-independent measures (scaling exponents) for discriminating the two classes of data over a broad range of record lengths. The wavelet-coefficient standard deviation at a scale near 32 heartbeat intervals, and its spectral counterpart near 1/32 cycles per interval, provide reliable results using record lengths just minutes long. A jittered integrate-and-fire model built around a fractal Gaussian-noise kernel provides a realistic, though not perfect, simulation of heartbeat sequences.
Pope, D.; Ramesh, H.; Gennari, R.; Corsini, G.; Maffezzini, M.; Hoekstra, H. J.; Mobarak, D.; Sunouchi, K.; Stotter, A.; West, C.; Audisio, R. A.
2006-01-01
Background: Cancer is a disease that particularly affects the elderly and, although surgery is the first treatment choice, many elderly cancer patients do not receive standard surgery because they are considered unfit for treatment due to an inaccurate estimation of operative risk. Pre-operative Ass
Energy Technology Data Exchange (ETDEWEB)
1994-09-01
The Department of Energy`s (DOE`s) planning for the disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of the waste. This report estimates volumes, radionuclide activities, and waste forms of GTCC LLW to the year 2035. It groups the waste into four categories, representative of the type of generator or holder of the waste: Nuclear Utilities, Sealed Sources, DOE-Held, and Other Generator. GTCC LLW includes activated metals (activation hardware from reactor operation and decommissioning), process wastes (i.e., resins, filters, etc.), sealed sources, and other wastes routinely generated by users of radioactive material. Estimates reflect the possible effect that packaging and concentration averaging may have on the total volume of GTCC LLW. Possible GTCC mixed LLW is also addressed. Nuclear utilities will probably generate the largest future volume of GTCC LLW with 65--83% of the total volume. The other generators will generate 17--23% of the waste volume, while GTCC sealed sources are expected to contribute 1--12%. A legal review of DOE`s obligations indicates that the current DOE-Held wastes described in this report will not require management as GTCC LLW because of the contractual circumstances under which they were accepted for storage. This report concludes that the volume of GTCC LLW should not pose a significant management problem from a scientific or technical standpoint. The projected volume is small enough to indicate that a dedicated GTCC LLW disposal facility may not be justified. Instead, co-disposal with other waste types is being considered as an option.
Alotaibi, Badriah M; Yezli, Saber; Bin Saeed, Abdul-Aziz A; Turkestani, Abdulhafeez; Alawam, Amnah H; Bieh, Kingsley L
2017-05-01
Hajj is one of the largest and the most ethnically and culturally diverse mass gatherings worldwide. The use of appropriate surveillance systems ensures timely information management for effective planning and response to infectious diseases threats during the pilgrimage. The literature describes infectious diseases prevention and control strategies for Hajj but with limited information on the operations and characteristics of the existing Hajj infectious diseases surveillance systems. We reviewed documents, including guidelines and reports from the Saudi Ministry of Health's database, to describe the characteristics of the infectious diseases surveillance systems that were operational during the 2015 Hajj, highlighting best practices and gaps and proposing strategies for strengthening and improvement. Using Pubmed and Embase online search engines and a combination of search terms including, 'mass gatherings' 'Olympics' 'surveillance' 'Hajj' 'health security', we explored the existing literature and highlighted some lessons learnt from other international mass gatherings. A regular indicator-based infectious disease surveillance system generates routine reports from health facilities within the Kingdom to the regional and central public health directorates all year round. During Hajj, enhanced indicator-based notifiable diseases surveillance systems complement the existing surveillance tool to ensure timely reporting of event information for appropriate action by public health officials. There is need to integrate the existing Hajj surveillance data management systems and to implement syndromic surveillance as an early warning system for infectious disease control during Hajj. International engagement is important to strengthen Hajj infectious diseases surveillance and to prevent disease transmission and globalization of infectious agents which could undermine global health security.
Sadeghifar, Hamidreza
2015-10-01
Developing general methods that rely on column data for the efficiency estimation of operating (existing) distillation columns has been overlooked in the literature. Most of the available methods are based on empirical mass transfer and hydraulic relations correlated to laboratory data. Therefore, these methods may not be sufficiently accurate when applied to industrial columns. In this paper, an applicable and accurate method was developed for the efficiency estimation of distillation columns filled with trays. This method can calculate efficiency as well as mass and heat transfer coefficients without using any empirical mass transfer or hydraulic correlations and without the need to estimate operational or hydraulic parameters of the column. E.g., the method does not need to estimate tray interfacial area, which can be its most important advantage over all the available methods. The method can be used for the efficiency prediction of any trays in distillation columns. For the efficiency calculation, the method employs the column data and uses the true rates of the mass and heat transfers occurring inside the operating column. It is highly emphasized that estimating efficiency of an operating column has to be distinguished from that of a column being designed.
Chen, Han-Taw; Lu, Chih-Han; Huang, Yao-Sheng; Liu, Kuo-Chi
2016-05-01
This study applies a three-dimensional computational fluid dynamics commercial software in conjunction with various flow models to estimate the heat transfer and fluid flow characteristics of the two-row plate-finned tube heat exchanger in staggered arrangement. The effect of air speed and fin spacing on the results obtained is investigated. Temperature and velocity distributions of air between the two fins and heat transfer coefficient on the fins are determined using the laminar flow and RNG k-ɛ turbulence models. More accurate results can be obtained, if the heat transfer coefficient obtained is close to the inverse results and matches existing correlations. Furthermore, the fin temperature measured at the selected locations also coincides with the experimental temperature data. The results obtained using the RNG k-ɛ turbulence model are more accurate than those using the laminar flow model. An interesting finding is the number of grid points may also need to change with fin spacing and air speed.
Scheiner, Stefan; Hellmich, Christian; Müller, Christoph; Bonitz, Lars; Kober, Cornelia
2015-10-01
In dentistry, clinical radiographs (also called X-ray images) reflect the intensity loss of an X-ray when being transmitted through the mandibular objects, and this loss is quantified in terms of grey values. While such images are standardly used for pathology detection by the experienced dentist, we here present a new method for getting more quantitative information out of such 2D radiographs, "extending" them into the third dimension. This "extension" requires consistent combination of X-ray physics (namely, X-ray intensity loss quantification along paths orthogonal to the panoramic clinical image and X-ray attenuation averaging for composite materials) with anatomically known upper and lower limits of vascular porosities in cortical and trabecular bone compartments. Correspondingly computed ranges of overall organ thicknesses are extremely narrow, suggesting adequate estimation of thickness characteristics from 2D radiographic panoramas used clinically, while predicted cortical and trabecular thickness ranges vary by ±8.47% and ±16.13%, respectively. The proposed method also identifies variations between thicknesses at similar anatomical locations left and right of the face's symmetry axis, and molar regions turn out to be thicker than those close to incisors. This paves the way to more detailed diagnostic activities, e.g. in combination with Finite Element simulations.
Mercado-Borrayo, B M; Schouwenaars, R; González-Chávez, J L; Ramírez-Zamora, R M
2013-01-01
A multi-analytical approach was used to develop a mathematical regression model to calculate the residual concentration of borate ions in water present at high initial content, as a function of the main physicochemical, mineralogical and electrokinetic characteristics after adsorption on five different types of iron and steel slag. The analytical techniques applied and slag properties obtained in this work were: X-ray Fluorescence for the identification of the main chemical compounds, X-ray Diffraction to determine crystalline phases, physical adsorption of nitrogen for the quantification of textural properties and zeta-potential for electrokinetic measurements of slag particles. Adsorption tests were carried out using the bottle-point technique and a highly concentrated borate solution (700 mg B/L) at pH 10, with a slag dose of 10 g/L. An excellent correlation between the residual concentration of boron and three independent variables (content of magnesium oxide, zeta potential and specific surface area) was established for the five types of slag tested in this work. This shows that the methodology based on a multi-analytical approach is a very strong and useful tool to estimate the performance of iron and steel slag as adsorbent of metalloids.
Li, Jia Wen; Chen, Xi Mei; Pun, Sio Hang; Mak, Peng Un; Gao, Yue Ming; Vai, Mang I; Du, Min
2013-01-01
Bit error rate (BER), which indicates the reliability of communicate channel, is one of the most important values in all kinds of communication system, including intra-body communication (IBC). In order to know more about IBC channel, this paper presents a new method of BER estimation for galvanic-type IBC using experimental eye-diagram and jitter characteristics. To lay the foundation for our methodology, the fundamental relationships between eye-diagram, jitter and BER are first reviewed. Then experiments based on human lower arm IBC are carried out using quadrature phase shift keying (QPSK) modulation scheme and 500 KHz carries frequency. In our IBC experiments, the symbol rate is from 10 Ksps to 100 Ksps, with two transmitted power settings, 0 dBm and -5 dBm. Finally, the BER results were obtained after calculation by experimental data through the relationships among eye-diagram, jitter and BER. These results are then compared with theoretical values and they show good agreement, especially when SNR is between 6 dB to 11 dB. Additionally, these results demonstrate assuming the noise of galvanic-type IBC channel as Additive White Gaussian Noise (AWGN) in previous study is applicable.
Directory of Open Access Journals (Sweden)
Aneri Choksi
2014-07-01
Full Text Available Criminal investigation always involves the identification of individuals involved in any incidence that is under question. Identification of individual is based on the available physical evidences. The most conventional method of identification of individuals is based on the fingerprints. There are certain instances wherein the identity of individual would be done based on certain anthropometric data such as measurements of various body parts although the complete identification is possible with fingerprints, DNA and patterns still the primary characteristic of identification such as stature and sex can be determined. In this study, an attempt has been made to establish the possible correlation between the palm length with the stature of individual. To get scrupulous results, the study has been done on the young adult population in the age range of 21-25 years. A total number of 500 subjects were considered for the study that includes 200 boys and 300 girls. Significant results were obtained. It was possible to deduce the correlation coefficient and multiplication factor for estimation of stature from palm length. The multiplication factor so deduced has been applied and regression analysis was done and was found to be significant and reliable .
Directory of Open Access Journals (Sweden)
Matt Nitzken
2016-03-01
Full Text Available To improve the tagged cardiac magnetic resonance (CMR image analysis, we propose a 3D (2D space + 1D time energy minimization framework, based on learning first- and second-order visual appearance models from voxel intensities. The former model approximates the marginal empirical distribution of intensities with two linear combinations of discrete Gaussians (LCDG. The second-order model considers an image of a sample from a translation–rotation invariant 3D Markov–Gibbs random field (MGRF with multiple pairwise spatiotemporal interactions within and between adjacent temporal frames. Abilities of the framework to accurately recover noise-corrupted strain slopes were experimentally evaluated and validated on 3D geometric phantoms and independently on in vivo data. In multiple noise and motion conditions, the proposed method outperformed comparative image filtering in restoring strain curves and reliably improved HARP strain tracking during the entirety of the cardiac cycle. According to these results, our framework can augment popular spectral domain techniques, such as HARP, by optimizing the spectral domain characteristics and thereby providing more reliable estimates of strain parameters.
Zheng, Jun; Ma, Xin-Tang; Zhou, Lan; Zhou, Qing-Yuan; Wang, Zhong-Qiong; Wang, Wei-Dong; Yin, Cheng-Qing
2011-08-01
The development characteristics and improvement measures of aquatic plants were studied in Shijiuyang Constructed Wetland (SCW) at its initial operation stage. SCW was a large-scale wetland aiming to help relieve the source water pollution in Jiaxing City. A checklist of vascular plants in SCW was built, and species composition, life forms, biomass and association distributions were examined. Our objectives were to examine the diversity and community structure of aquatic plants in SCW at its initial operation stage, and to find out the possible hydrophyte improvement measures. The survey results showed that there were 49 vascular plant species belonging to 41 genera, 25 families in SCW, which greatly exceeded the artificially transplanted 13 species. The life forms of present aquatic plants in SCW were dominated by hygrophilous plants (20 species) and emerged plants (17 species), which accounted for 75.5% of the total number of aquatic plants. The aquatic plants transplanted artificially were dominated by emerged plants (accounted for 69.2%), while those naturally developed were predominated by hygrophilous plants (accounted for 47.2%). The horizontal distribution of aquatic plant community in SCW was mixed in the form of mosaics, which made up typical association complex. Except association Aeschynomene indica L., the dominant species of other associations were all those transplanted artificially. The naturally grown species scattered throughout the SCW and only occupied a small percentage. A marked difference was detected on the species and species richness of aquatic plants in different regions of SCW. Biomass of aquatic plant associations in SCW was 167.7 t. SCW has shown a trend of succession heading for quick increase of plant diversity at the primary operation stage. This trend provides a good material base for the future stable community of aquatic plants in SCW. According to the current status of aquatic plants, some suggestions were put forward on the
McCarthy, Peter M.; Sando, Roy; Sando, Steven K.; Dutton, DeAnn M.
2016-04-05
The U.S. Geological Survey, in cooperation with the Montana Department of Environmental Quality and the Montana Department of Natural Resources and Conservation, developed regional regression equations based on basin and streamflow characteristics for streamflow-gaging stations through water year 2009 that can be used to estimate streamflow characteristics for ungaged sites in western Montana. The regression equations allow estimation of low-flow frequencies; mean annual and mean monthly streamflows; and the 20-, 50-, and 80-percent durations for annual and monthly duration streamflows for ungaged sites in western Montana that are unaffected by regulation.
Zhou, Si-Da; Heylen, Ward; Sas, Paul; Liu, Li
2014-05-01
This paper investigates the problem of modal parameter estimation of time-varying structures under unknown excitation. A time-frequency-domain maximum likelihood estimator of modal parameters for linear time-varying structures is presented by adapting the frequency-domain maximum likelihood estimator to the time-frequency domain. The proposed estimator is parametric, that is, the linear time-varying structures are represented by a time-dependent common-denominator model. To adapt the existing frequency-domain estimator for time-invariant structures to the time-frequency methods for time-varying cases, an orthogonal polynomial and z-domain mapping hybrid basis function is presented, which has the advantageous numerical condition and with which it is convenient to calculate the modal parameters. A series of numerical examples have evaluated and illustrated the performance of the proposed maximum likelihood estimator, and a group of laboratory experiments has further validated the proposed estimator.