Measurement and Calculation Methods of a Stem Image Information
Institute of Scientific and Technical Information of China (English)
Yang Hua; Meng Xianyu; Liu Yan; Cheng Jun
2006-01-01
The paper shows a study on 2-D stem image information collected by a digital camera.Information on a single stem is obtained through calculations after the application of the direct linear transformation model of close-range photogrammetry and binocular stereo vision technology,so that the calculating problem between stem image information and its 2-D coordinate can be solved.Furthermore,the 2-D processing methodology for measuring tree image information simplifies calculating equations and increases calculating speed.Although computer stereo vision techniques for collecting parameters of a single stem shape are comparative,complicated,and expensive,research indicates the efficiently and feasibility of closerange photogrammetry for stem image information.
Methods for calculating phase angle from measured whole body bioimpedance modulus
Nordbotten, Bernt J.; Martinsen, Ørjan G.; Grimnes, Sverre
2010-04-01
Assuming the Cole equation we have developed a method to calculate the Cole parameters (R0, R∞, α, τZ) and the phase angle from four frequency measurements of impedance modulus values. The values obtained compare well with impedance measurements obtained using the Solatron 1294/1260 as obtained when making whole body measurements on five persons. We have also performed calculations using an algorithm based on the Kramers-Kronig approach. The results which are presented show that it is possible to obtain complete body impedance data combining relatively simple measurements with advanced calculation using a laptop. This extends the potential of portable equipment, since the measurements will require less instrumentation.
Institute of Scientific and Technical Information of China (English)
Ge Yu-Cheng
2008-01-01
This paper calculates quantum-mechanically the photoelectron energy spectra excited by attosecond x-rays in the presence of a few-cycle laser. A photoelectron laser phase determination method is used for precise measurements of the pulse natural properties of x-ray intensity and the instantaneous frequency profiles. As a direct procedure without any previous pulse profile assumptions and time-resolved measurements as well as data fitting analysis, this method can be used to improve the time resolutions of attosecond timing and measurements with metrological precision. The measurement range is half of a laser optical cycle.
Methods for measuring and calculating the external load of powered supports
Institute of Scientific and Technical Information of China (English)
Hua Zhu; Xiaoyan Yu; Shirong Ge; Shibo Wang
2003-01-01
Taking the chock shield supports as the object of study, methods for measuring and calculating the external load of powered supports were discussed. Selecting the angle parameters as variables, the simple formulae of interactive computation with respect to the work angles of a powered support were deduced and verified by an example. Furthermore, the formulae determining the magnitude, direction and action point of the external load were put forward. The investigation results have provided a sound basis for the software design of the intelligent instrument for load measuring of powered supports.
An optimised method for calculating the O+-O collision parameter from aeronomical measurements
Directory of Open Access Journals (Sweden)
A. Aruliah
Full Text Available A study has been made of the interaction between the thermosphere and the ionosphere at high latitudes, with particular regard to the value of the O+-O collision parameter. The European incoherent scatter radar (EISCAT was used to make tristatic measurements of plasma parameters at F-region altitudes while simultaneous measurements of the neutral wind were made by a Fabry-Perot interferometer (FPI. The radar data were used to derive the meridional neutral winds in a way similar to that used by previous authors. The accuracy of this technique at high latitudes is reduced by the dynamic nature of the auroral ionosphere and the presence of significant vertical winds. The derived winds were compared with the meridional winds measured by the FPI. For each night, the value of the O+-O collision parameter which produced the best agreement between the two data sets was found. The precision of the collision frequency found in this way depends on the accuracy of the data. The statistical method was critically examined in an attempt to account for the variability in the data sets. This study revealed that systematic errors in the data, if unaccounted for by the analysis, have a tendency to increase the value of the derived collision frequency. Previous analyses did not weight each data set in order to account for the quality of the data; an improved method of analysis is suggested.
Bianco, Federica B; Oh, Seung Man; Fierroz, David; Liu, Yuqian; Kewley, Lisa; Graur, Or
2015-01-01
We present the open-source Python code pyMCZ that determines oxygen abundance and its distribution from strong emission lines in the standard metallicity scales, based on the original IDL code of Kewley & Dopita (2002) with updates from Kewley & Ellison (2008), and expanded to include more recently developed scales. The standard strong-line diagnostics have been used to estimate the oxygen abundance in the interstellar medium through various emission line ratios in many areas of astrophysics, including galaxy evolution and supernova host galaxy studies. We introduce a Python implementation of these methods that, through Monte Carlo (MC) sampling, better characterizes the statistical reddening-corrected oxygen abundance confidence region. Given line flux measurements and their uncertainties, our code produces synthetic distributions for the oxygen abundance in up to 13 metallicity scales simultaneously, as well as for E(B-V), and estimates their median values and their 66% confidence regions. In additi...
Bianco, F. B.; Modjaz, M.; Oh, S. M.; Fierroz, D.; Liu, Y. Q.; Kewley, L.; Graur, O.
2016-07-01
We present the open-source Python code pyMCZ that determines oxygen abundance and its distribution from strong emission lines in the standard metallicity calibrators, based on the original IDL code of Kewley and Dopita (2002) with updates from Kewley and Ellison (2008), and expanded to include more recently developed calibrators. The standard strong-line diagnostics have been used to estimate the oxygen abundance in the interstellar medium through various emission line ratios (referred to as indicators) in many areas of astrophysics, including galaxy evolution and supernova host galaxy studies. We introduce a Python implementation of these methods that, through Monte Carlo sampling, better characterizes the statistical oxygen abundance confidence region including the effect due to the propagation of observational uncertainties. These uncertainties are likely to dominate the error budget in the case of distant galaxies, hosts of cosmic explosions. Given line flux measurements and their uncertainties, our code produces synthetic distributions for the oxygen abundance in up to 15 metallicity calibrators simultaneously, as well as for E(B- V) , and estimates their median values and their 68% confidence regions. We provide the option of outputting the full Monte Carlo distributions, and their Kernel Density estimates. We test our code on emission line measurements from a sample of nearby supernova host galaxies (z https://github.com/nyusngroup/pyMCZ.
Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.
2016-02-01
The accuracy, precision, and reliability of ultrasonic thickness structural health monitoring systems are discussed in-cluding the influence of systematic and environmental factors. To quantify some of these factors, a compression wave ultrasonic thickness structural health monitoring experiment is conducted on a flat calibration block at ambient temperature with forty four thin-film sol-gel transducers and various time-of-flight thickness calculation methods. As an initial calibration, the voltage response signals from each sensor are used to determine the common material velocity as well as the signal offset unique to each calculation method. Next, the measurement precision of the thickness error of each method is determined with a proposed weighted censored relative maximum likelihood analysis technique incorporating the propagation of asymmetric measurement uncertainty. The results are presented as upper and lower confidence limits analogous to the a90/95 terminology used in industry recognized Probability-of-Detection assessments. Future work is proposed to apply the statistical analysis technique to quantify measurement precision of various thickness calculation methods under different environmental conditions such as high temperature, rough back-wall surface, and system degradation with an intended application to monitor naphthenic acid corrosion in oil refineries.
DEFF Research Database (Denmark)
Barrera Figueroa, Salvador; Rasmussen, Knud; Jacobsen, Finn
2009-01-01
Typically, numerical calculations of the pressure, free-field, and random-incidence response of a condenser microphone are carried out on the basis of an assumed displacement distribution of the diaphragm of the microphone; the conventional assumption is that the displacement follows a Bessel fun...
International Nuclear Information System (INIS)
The predictions of the ARGOSY method of calculation are compared with buckling and reaction rate measurements on graphite lattices containing plutonium enriched oxide cluster fuels. Most of the measurements were obtained on one lattice pitch giving a graphite-to-fuel volume ratio similar to that in the Windscale A.G.R. Apart from a reduction of 10% in the values of the capture and fission resonance integrals (4eV to 10KeV) of all nuclides the method as coded in ARGOSY III uses basic nuclear data. It is shown in this report that the buckling predictions of ARGOSY III at room temperature are in agreement with the experimentally determined values within approximately the experimental error, i.e. equivalent to ±0.5% in reactivity. When systematic errors are removed, however, a linear trend with the fraction of fissions occurring in Pu 239 is evident; the calculated reactivity being (0.6 ± 0.3)% low for zero Pu239 content and (0.6 + 0.3)% high for fuel with 80% of fission occurring in Pu 239. The experimentally determined change of buckling between 20 and 390 deg C is predicted to within the experimental error, i,e. equivalent to ± 0.7 mn/deg C. Reaction rate ratios and radial power distributions at all temperatures are predicted well by ARGOSY III. (author)
Methods for Melting Temperature Calculation
Hong, Qi-Jun
the melting temperature is a design criterion. We present in detail two examples of refractory materials. First, we demonstrate how key material properties that provide guidance in the design of refractory materials can be accurately determined via ab initio thermodynamic calculations in conjunction with experimental techniques based on synchrotron X-ray diffraction and thermal analysis under laser-heated aerodynamic levitation. The properties considered include melting point, heat of fusion, heat capacity, thermal expansion coefficients, thermal stability, and sublattice disordering, as illustrated in a motivating example of lanthanum zirconate (La2Zr2O7). The close agreement with experiment in the known but structurally complex compound La2Zr 2O7 provides good indication that the computation methods described can be used within a computational screening framework to identify novel refractory materials. Second, we report an extensive investigation into the melting temperatures of the Hf-C and Hf-Ta-C systems using ab initio calculations. With melting points above 4000 K, hafnium carbide (HfC) and tantalum carbide (TaC) are among the most refractory binary compounds known to date. Their mixture, with a general formula TaxHf 1-xCy, is known to have a melting point of 4215 K at the composition Ta4HfC 5, which has long been considered as the highest melting temperature for any solid. Very few measurements of melting point in tantalum and hafnium carbides have been documented, because of the obvious experimental difficulties at extreme temperatures. The investigation lets us identify three major chemical factors that contribute to the high melting temperatures. Based on these three factors, we propose and explore a new class of materials, which, according to our ab initio calculations, may possess even higher melting temperatures than Ta-Hf-C. This example also demonstrates the feasibility of materials screening and discovery via ab initio calculations for the
Energy Technology Data Exchange (ETDEWEB)
Jacquet, X.; Casoli, P.; Authier, N.; Rousseau, G. [CEA, Centre de Valduc, 21120 Is-sur-Tille (France); Barsu, C. [Pl. de la fontaine, 25410 Corcelles-Ferrieres (France)
2011-07-01
Caliban is a cylindrical metallic core reactor mainly composed of uranium 235. It is operated by the Criticality and Neutron Science Research Laboratory located at the French Atomic Energy Commission research center in Valduc. As with other fast burst reactors, Caliban is used extensively for determining the responses of electronic parts or other objects and materials to neutron-induced displacements. Therefore, Caliban's irradiation characteristics, and especially its central cavity neutron spectrum, have to be very accurately evaluated. The foil activation method has been used in the past by the Criticality and Neutron Science Research Laboratory to evaluate the neutron spectrum of the different facilities it operated, and in particular to characterize the Caliban cavity spectrum. In order to strengthen and to improve our knowledge of the Caliban cavity neutron spectrum and to reduce the uncertainties associated with the available evaluations, new measurements have been performed on the reactor and interpreted by the foil activation method. A sensor set has been selected to sample adequately the studied spectrum. Experimental measured reaction rates have been compared to the results from UMG spectrum unfolding software and to values obtained with the activation code Fispact. Experimental and simulation results are overall in good agreement, although gaps exist for some sensors. UMG software has also been used to rebuild the Caliban cavity neutron spectrum from activation measurements. For this purpose, a default spectrum is needed, and one has been calculated with the Monte-Carlo transport code Tripoli 4 using the benchmarked Caliban description. (authors)
Vreede, F. A.
1981-05-01
The manual of instructions for the user of the CSIR triaxial rock stress measuring equipment is critically examined. It is shown that the values of the rock stresses can be obtained from the strain gauge records by means of explicit formulae, which makes the manual's computer program obsolete. Furthermore statistical methods are proposed to check for faulty data and inhomogeneity in rock properties and virgin stress. The possibility of non-elastic behavior of the rock during the test is also checked. A new computer program based on the explicit functions and including the check calculations is presented. It is much more efficient than the one in the manual since it does not require computer sub-routines, allowing it to be used directly on any modern computer. The output of the new program is in a format suitable for direct inclusion in the report of an investigation using strain cell results.
Deconstructing Calculation Methods: Part 1
Thompson, Ian
2007-01-01
The aim of this series of four articles is to look critically, and in some detail, at the primary strategy approach to written calculation, as set out on pages 5 to 16 of the "Guidance paper" "Calculation." The underlying principle of that approach is that children should use mental methods whenever they are appropriate, whereas for calculations…
Energy Technology Data Exchange (ETDEWEB)
Smith, L.A.; Gallmeier, F.X. [Oak Ridge Institute for Science and Energy, TN (United States); Gehin, J.C. [Oak Ridge National Lab., TN (United States)] [and others
1995-05-01
The FOEHN critical experiment was analyzed to validate the use of multigroup cross sections and Oak Ridge National Laboratory neutronics computer codes in the design of the Advanced Neutron Source. The ANSL-V 99-group master cross section library was used for all the calculations. Three different critical configurations were evaluated using the multigroup KENO Monte Carlo transport code, the multigroup DORT discrete ordinates transport code, and the multigroup diffusion theory code VENTURE. The simple configuration consists of only the fuel and control elements with the heavy water reflector. The intermediate configuration includes boron endplates at the upper and lower edges of the fuel element. The complex configuration includes both the boron endplates and components in the reflector. Cross sections were processed using modules from the AMPX system. Both 99-group and 20-group cross sections were created and used in two-dimensional models of the FOEHN experiment. KENO calculations were performed using both 99-group and 20-group cross sections. The DORT and VENTURE calculations were performed using 20-group cross sections. Because the simple and intermediate configurations are azimuthally symmetric, these configurations can be explicitly modeled in R-Z geometry. Since the reflector components cannot be modeled explicitly using the current versions of these codes, three reflector component homogenization schemes were developed and evaluated for the complex configuration. Power density distributions were calculated with KENO using 99-group cross sections and with DORT and VENTURE using 20-group cross sections. The average differences between the measured values and the values calculated with the different computer codes range from 2.45 to 5.74%. The maximum differences between the measured and calculated thermal flux values for the simple and intermediate configurations are {approx} 13%, while the average differences are < 8%.
Comparison of methods for calculating water erosion
Svobodová, Pavlína
2011-01-01
Bachelor thesis presents a comparison of methods for calculating water erosion. The aim is to summarize available evidence concerning the problems of water erosion. There are presented some methods how to calculate average annual erosion of soils, and selected models for calculating the erosion immediately. There are also listed possible erosion control measures through which we can at least slow the effects of erosion, rather than stop completely.
Directory of Open Access Journals (Sweden)
Мaryna O. Golofeyeva
2015-12-01
Full Text Available The effective use of heterogeneous non-metallic materials and structures needs measurement of reliable values of dissipation characteristics, as well as common factors of their change during the loading process. Aim: The aim of this study is to prepare the budget for measurement uncertainty of dissipative properties of composite materials. Materials and Methods: The method used to study the vibrational energy dissipation characteristics based on coupling of vibrations damping decrement and acoustic velocity in a non-metallic heterogeneous material is reviewed. The proposed method allows finding the dependence of damping on vibrations amplitude and frequency of strain-stress state of material. Results: Research of the accuracy of measurement method during the definition of decrement attenuation of fluctuations in synthegran was performed. The international approach for evaluation of measurements quality is used. It includes the common practice international rules for uncertainty expression and their summation. These rules are used as internationally acknowledged confidence measure to the measurement results, which includes testing. The uncertainties budgeting of acoustic method for measurement of dissipative properties of materials were compiled. Conclusions: It was defined that there are two groups of reasons resulting in errors during measurement of materials dissipative properties. The first group of errors contains of parameters changing of calibrated bump in tolerance limits, displacement of sensor in repeated placement to measurement point, layer thickness variation of contact agent because of irregular hold-down of resolvers to control surface, inaccuracy in reading and etc. The second group of errors is linked with density and Poisson’s ratio measurement errors, distance between sensors, time difference between signals of vibroacoustic sensors.
Friction and wear calculation methods
Kragelsky, I V; Kombalov, V S
1981-01-01
Friction and Wear: Calculation Methods provides an introduction to the main theories of a new branch of mechanics known as """"contact interaction of solids in relative motion."""" This branch is closely bound up with other sciences, especially physics and chemistry. The book analyzes the nature of friction and wear, and some theoretical relationships that link the characteristics of the processes and the properties of the contacting bodies essential for practical application of the theories in calculating friction forces and wear values. The effect of the environment on friction and wear is a
Schibbye, Peter; Ghaderi, Ata; Ljótsson, Brjánn; Hedman, Erik; Lindefors, Nils; Rück, Christian; Kaldo, Viktor
2014-01-01
Early change can predict outcome of psychological treatment, especially in cognitive behavior therapy. However, the optimal operationalization of "early change" for maximizing its predictive ability, and differences in predictive ability of disorder-specific versus general mental health measures has yet to be clarified. This study aimed to investigate how well early change predicted outcome depending on the week it was measured, the calculation method (regression slope or simple subtraction), the type of measures used, and the target disorder. During 10-15 weeks of internet-based cognitive behavior therapy for depression, social anxiety disorder, or panic disorder, weekly ratings were collected through both disorder-specific measures and general measures (Outcome Questionnaire-45 (OQ-45) and Clinical Outcomes in Routine Evaluation-10 (CORE-10)). With outcome defined as the disorder-specific measure, change at week four was the optimal predictor. Slope and subtraction methods performed equally well. The OQ-45 explained 18% of outcome for depression, 14% for social anxiety disorder, and 0% for panic disorder. Corresponding values for CORE-10 were 23%, 29%, and 25%. Specific measures explained 41%, 43%, and 34% respectively: this exceeded the ability of general measures also when they predicted themselves. We conclude that a simple calculation method with a disorder-specific measure at week four seems to provide a good choice for predicting outcome in time-limited cognitive behavior therapy. PMID:24959666
Directory of Open Access Journals (Sweden)
Peter Schibbye
Full Text Available Early change can predict outcome of psychological treatment, especially in cognitive behavior therapy. However, the optimal operationalization of "early change" for maximizing its predictive ability, and differences in predictive ability of disorder-specific versus general mental health measures has yet to be clarified. This study aimed to investigate how well early change predicted outcome depending on the week it was measured, the calculation method (regression slope or simple subtraction, the type of measures used, and the target disorder. During 10-15 weeks of internet-based cognitive behavior therapy for depression, social anxiety disorder, or panic disorder, weekly ratings were collected through both disorder-specific measures and general measures (Outcome Questionnaire-45 (OQ-45 and Clinical Outcomes in Routine Evaluation-10 (CORE-10. With outcome defined as the disorder-specific measure, change at week four was the optimal predictor. Slope and subtraction methods performed equally well. The OQ-45 explained 18% of outcome for depression, 14% for social anxiety disorder, and 0% for panic disorder. Corresponding values for CORE-10 were 23%, 29%, and 25%. Specific measures explained 41%, 43%, and 34% respectively: this exceeded the ability of general measures also when they predicted themselves. We conclude that a simple calculation method with a disorder-specific measure at week four seems to provide a good choice for predicting outcome in time-limited cognitive behavior therapy.
International Nuclear Information System (INIS)
Extensive neutron and gamma attenuation measurements have been performed in magnetite and ordinary concrete up to a depth of 2 metres in order to study the accuracy attainable by some shield calculation methods. The effect of thin, heavy layers (Pb) has also been studied. Experimental facilities and instrumentation, especially the foil detection methods used for thermal and epithermal neutrons, are described in some detail. Great weight is laid upon a thorough error analysis. The fluxes measured are compared to those calculated by an earlier version of the British 18-group removal method (RASH B3), by an improved removal method (NRN) developed at AB Atomenergi, and by numerical integration of the Boltzmann equation (NIOBE). The results show that shielding calculations with the newer methods give fluxes that are generally within a factor of 2-3 from the true values. A greater accuracy seems to be difficult to obtain in practice in spite of possible improvements in the mathematical solution of the transport problem. The greatest errors originate in the translation between the true and calculation geometries in the uncertainty of material properties in the case of concrete, and in approximations and inaccuracies of radiation sources
Jones, Thomas; Laughlin, Thomas
2009-01-01
Nothing could be more effective than a wilderness experience to demonstrate the importance of conserving biodiversity. When that is not possible, though, there are computer models with several features that are helpful in understanding how biodiversity is measured. These models are easily used when natural resources, transportation, and time…
超声波流量测量中流速计算方法的对比%Comparison of flow rate calculation method for ultrasonic flow measurement
Institute of Scientific and Technical Information of China (English)
于洋; 宗光华; 丁凤林
2013-01-01
超声波流量计(UFM,Ultrasonic Flow Meter)通过测量管路中顺流和逆流方向的超声波传播时间变化计算流速,因此超声波传播时间的准确测量对流量计的精度影响至关重要.对超声波流量计的测量方法进行研究,从环境温度的变化、时间测量的准确性、不确定度的计算3个方面,对比超声波传播时间差法和频率差法对流量测量精度的影响.通过超声波流量测量实验,验证了在流量计未校准的情况下,与频率差法相比,时间差法的测量精度更高,且其校准系数曲线的线性度更好,校准后可在全流量范围内获得更高的测量精度.%Ultrasonic flow meter ( UFM ) calculates the flow rate, by measuring the difference of ultrasound transit time between the upstream direction and downstream direction. For the purpose of accurate flow measurement, transit time difference method and frequency difference method were compared from three aspects; change of environment temperature, accuracy of time measurement, and uncertainty calculation. Ultrasonic flow measurement experiment shows, when the flow meter is not calibrated, compared with frequency difference method, transit time difference method can achieve better accuracy. The calibrated factor for the transit time difference method is more linear, so better accuracy is achieved for full flow range measurement.
Kurhan, D. N.; Lapsheva, N. M.
2013-01-01
One of the ways to increase safety and operation of seamless path is the determination of the stress-strain state rail lashes that enables you to warn and prevent failures continuous welded rail. It is known that significant longitudinal force are caused by limitations of the temperature regime of continuous welded rail and can lead to the release. For long-term development and improvement of the theory of thermal stress state of continuous welded rail have created several different methods f...
International Nuclear Information System (INIS)
This thesis presents the radiative corrections to the virtual compton scattering and the magnetic method adopted in the Hall A at Jefferson Laboratory, to measure the electrons beam energy with an accuracy of 104. The virtual compton scattering experiments allow the access to the generalised polarizabilities of the protons. The extraction of these polarizabilities is obtained by the experimental and theoretical cross sections comparison. That's why the systematic errors and the radiative effects of the experiments have to be controlled very seriously. In this scope, a whole calculation of the internal radiative corrections has been realised in the framework of the quantum electrodynamic. The method of the dimensional regularisation has been used to the treatment of the ultraviolet and infra-red divergences. The absolute measure method of the energy, takes into account the magnetic deviation, made up of eight identical dipoles. The energy is determined from the deviation angle calculation of the beam and the measure of the magnetic field integral along the deviation
Calculation Methods for Wallenius’ Noncentral Hypergeometric Distribution
DEFF Research Database (Denmark)
Fog, Agner
2008-01-01
conditional distribution of independent binomial variates given their sum. No reliable calculation method for Wallenius' noncentral hypergeometric distribution has hitherto been described in the literature. Several new methods for calculating probabilities from Wallenius' noncentral hypergeometric...
ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS
Directory of Open Access Journals (Sweden)
Jan Dostal
2015-12-01
Full Text Available This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.
American Society for Testing and Materials. Philadelphia
2005-01-01
1.1 This test method covers the calculation from heat transfer theory of the stagnation enthalpy from experimental measurements of the stagnation-point heat transfer and stagnation pressure. 1.2 Advantages 1.2.1 A value of stagnation enthalpy can be obtained at the location in the stream where the model is tested. This value gives a consistent set of data, along with heat transfer and stagnation pressure, for ablation computations. 1.2.2 This computation of stagnation enthalpy does not require the measurement of any arc heater parameters. 1.3 Limitations and ConsiderationsThere are many factors that may contribute to an error using this type of approach to calculate stagnation enthalpy, including: 1.3.1 TurbulenceThe turbulence generated by adding energy to the stream may cause deviation from the laminar equilibrium heat transfer theory. 1.3.2 Equilibrium, Nonequilibrium, or Frozen State of GasThe reaction rates and expansions may be such that the gas is far from thermodynamic equilibrium. 1.3.3 Noncat...
Methods in nuclear reactors calculations
International Nuclear Information System (INIS)
Studies are made of the neutron transport equation corresponding to the the real and virtual reactors, as well as the starting hypotheses. Methods are developed to solve the transport equation in slab geometry, and Pl; Bl; Ml; Sn and discrete ordinates approximations. (Author)
International Nuclear Information System (INIS)
Accurate and transparent measurement and monitoring of radiologist workload is highly desirable for management of daily workflow in a radiology department, and for informing decisions on department staffing needs. It offers the potential for benchmarking between departments and assessing future national workforce and training requirements. We describe a technique for quantifying, with minimum subjectivity, all the work carried out by radiologists in a tertiary department. Six broad categories of clinical activities contributing to radiologist workload were identified: reporting, procedures, trainee supervision, clinical conferences and teaching, informal case discussions, and administration related to referral forms. Time required for reporting was measured using data from the radiology information system. Other activities were measured by observation and timing by observers, and based on these results and extensive consultation, the time requirements and frequency of each activity was agreed on. An activity list was created to record this information and to calculate the total clinical hours required to meet the demand for radiologist services. Diagnostic reporting accounted for approximately 35% of radiologist clinical time; procedures, 23%; trainee supervision, 15%; conferences and tutorials, 14%; informal case discussions, 10%; and referral-related administration, 3%. The derived data have been proven reliable for workload planning over the past 3 years. A transparent and robust method of measuring radiologists' workload has been developed, with subjective assessments kept to a minimum. The technique has value for daily workload and longer term planning. It could be adapted for widespread use.
Pile Load Capacity – Calculation Methods
Directory of Open Access Journals (Sweden)
Wrana Bogumił
2015-12-01
Full Text Available The article is a review of the current problems of the foundation pile capacity calculations. The article considers the main principles of pile capacity calculations presented in Eurocode 7 and other methods with adequate explanations. Two main methods are presented: α – method used to calculate the short-term load capacity of piles in cohesive soils and β – method used to calculate the long-term load capacity of piles in both cohesive and cohesionless soils. Moreover, methods based on cone CPTu result are presented as well as the pile capacity problem based on static tests.
Approximate methods in gamma-ray skyshine calculations
International Nuclear Information System (INIS)
An approximate computational method for gamma-ray skyshine calculations is described. The method is suitable for a source collimated uniformly about the vertical and accounts for uniform overhead concrete shielding above the source. Results of calculations are compared to measurements as well as results of other calculations
New method for calculation of integral characteristics of thermal plumes
DEFF Research Database (Denmark)
Zukowska, Daria; Popiolek, Zbigniew; Melikov, Arsen Krikor
2008-01-01
A method for calculation of integral characteristics of thermal plumes is proposed. The method allows for determination of the integral parameters of plumes based on speed measurements performed with omnidirectional low velocity thermoanemometers. The method includes a procedure for calculation...... occupant. The improvement in calculation of the characteristics of the thermal plume achieved with the developed method, in comparison with methods used and reported in the literature, is demonstrated....
Measuring method and calculation of the evaporation rate for LNG storage tank%LNG储罐日蒸发率测量方法及计算
Institute of Scientific and Technical Information of China (English)
李晓明; 许燕; 姚淑婷; 王冰; 李国艳
2013-01-01
The evaporation rate is an important index of the insulation performance for LNG storage tank,and it is beneficial to better understand the evaporation rote for safe operation for LNG storage tank.Combined with the definition and standard of the evaporation rate of storage tank,and based on the actual operation situations,several measuring methods and calculation formulas of the evaporation rate for LNG storage tank were given in this paper,and the applicability and technological conditions of different measuring methods were also discussed.%日蒸发率是衡量LNG储罐绝热性能的重要指标,有效了解储罐日蒸发率,将有利于LNG储罐安全运行的维护.结合储罐日蒸发率的定义和标准,根据实际操作情况,给出了几种测量LNG储罐日蒸发率的方法及其计算公式,并论述了各种测量方法的适用性和工艺条件.
Glass dissolution rate measurement and calculation revisited
Fournier, Maxime; Ull, Aurélien; Nicoleau, Elodie; Inagaki, Yaohiro; Odorico, Michaël; Frugier, Pierre; Gin, Stéphane
2016-08-01
Aqueous dissolution rate measurements of nuclear glasses are a key step in the long-term behavior study of such waste forms. These rates are routinely normalized to the glass surface area in contact with solution, and experiments are very often carried out using crushed materials. Various methods have been implemented to determine the surface area of such glass powders, leading to differing values, with the notion of the reactive surface area of crushed glass remaining vague. In this study, around forty initial dissolution rate measurements were conducted following static and flow rate (SPFT, MCFT) measurement protocols at 90 °C, pH 10. The international reference glass (ISG), in the forms of powders with different particle sizes and polished monoliths, and soda-lime glass beads were examined. Although crushed glass grains clearly cannot be assimilated with spheres, it is when using the samples geometric surface (Sgeo) that the rates measured on powders are closest to those found for monoliths. Overestimation of the reactive surface when using the BET model (SBET) may be due to small physical features at the atomic scale-contributing to BET surface area but not to AFM surface area. Such features are very small compared with the thickness of water ingress in glass (a few hundred nanometers) and should not be considered in rate calculations. With a SBET/Sgeo ratio of 2.5 ± 0.2 for ISG powders, it is shown here that rates measured on powders and normalized to Sgeo should be divided by 1.3 and rates normalized to SBET should be multiplied by 1.9 in order to be compared with rates measured on a monolith. The use of glass beads indicates that the geometric surface gives a good estimation of glass reactive surface if sample geometry can be precisely described. Although data clearly shows the repeatability of measurements, results must be given with a high uncertainty of approximately ±25%.
Nonlinear calculating method of pile settlement
Institute of Scientific and Technical Information of China (English)
贺炜; 王桂尧; 王泓华
2008-01-01
To study calculating method of settlement on top of extra-long large-diameter pile, the relevant research results were summarized. The hyperbola model, a nonlinear load transfer function, was introduced to establish the basic differential equation with load transfer method. Assumed that the displacement of pile shaft was the high order power series of buried depth, through merging the same orthometric items and arranging the relevant coefficients, the solution which could take the nonlinear pile-soil interaction and stratum properties of soil into account was solved by power series. On the basis of the solution, by determining the load transfer depth with criterion of settlement on pile tip, the method by making boundary conditions compatible was advised to solve the load-settlement curve of pile. The relevant flow chart and mathematic expressions of boundary conditions were also listed. Lastly, the load transfer methods based on both two-broken-line model and hyperbola model were applied to analyzing a real project. The related coefficients of fitting curves by hyperbola were not less than 0.96, which shows that the hyperbola model is truthfulness, and is propitious to avoid personal error. The calculating value of load-settlement curve agrees well with the measured one, which indicates that it can be applied in engineering practice and making the theory that limits the design bearing capacity by settlement on pile top comes true.
Jiang, M.; Marr, L. C.; Dunlea, E.; Herndon, S.; Jayne, J.; Rogers, T.; Knighton, B.; Zavala, M.; Molina, L. T.; Molina, M. J.
2004-12-01
Aerosol black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs) are two products of carbonaceous fuel combustion that are of major concern for urban air quality and global climate change. As part of the Mexico City Metropolitan Area field campaign in April 2003 (MCMA-2003), a mobile laboratory drove throughout the city and chased vehicles to measure pollutants in their exhaust emissions. The laboratory is a van designed and built by Aerodyne Research, Inc. and is equipped with a suite of gas and particle analyzers, including an aethalometer that measures BC and a photoemission aerosol sensor that measures particle-bound PAHs. The main goal of this research is to determine fuel-based emission factors, or the mass of BC and PAH emitted per volume of fuel burned, for Mexico City¡_s vehicle fleet. We can then calculate the megacity¡_s emission inventory of these compounds, which is important on both the urban and global scales. In previous analyses, the mobile laboratory has been used to target emissions from specific vehicles. While chasing events can be analyzed to obtain emission factors for specific vehicles, data from the entire time period while the lab is driving through the streets, whether chasing individual vehicles or not, can also provide valuable information about mobile source emissions. The laboratory continuously samples ambient air from an inlet at the front of the van, and it is always ¡°seeing¡± exhaust plumes from the vehicles around it. This ¡°macroscopic¡± approach that considers all vehicles on the road, similar to tunnel and remote sensing studies, complements the ¡°microscopic¡± approach that focuses on individual vehicles. We have developed a method that automatically identifies exhaust plumes and quantifies emission factors from data collected by the mobile lab. While 200 individual chasing events were identified during the field campaign, over 40,000 exhaust plume points were identified using the macroscopic approach. The
Assessment of seismic margin calculation methods
Energy Technology Data Exchange (ETDEWEB)
Kennedy, R.P.; Murray, R.C.; Ravindra, M.K.; Reed, J.W.; Stevenson, J.D.
1989-03-01
Seismic margin review of nuclear power plants requires that the High Confidence of Low Probability of Failure (HCLPF) capacity be calculated for certain components. The candidate methods for calculating the HCLPF capacity as recommended by the Expert Panel on Quantification of Seismic Margins are the Conservative Deterministic Failure Margin (CDFM) method and the Fragility Analysis (FA) method. The present study evaluated these two methods using some representative components in order to provide further guidance in conducting seismic margin reviews. It is concluded that either of the two methods could be used for calculating HCLPF capacities. 21 refs., 9 figs., 6 tabs.
Assessment of seismic margin calculation methods
International Nuclear Information System (INIS)
Seismic margin review of nuclear power plants requires that the High Confidence of Low Probability of Failure (HCLPF) capacity be calculated for certain components. The candidate methods for calculating the HCLPF capacity as recommended by the Expert Panel on Quantification of Seismic Margins are the Conservative Deterministic Failure Margin (CDFM) method and the Fragility Analysis (FA) method. The present study evaluated these two methods using some representative components in order to provide further guidance in conducting seismic margin reviews. It is concluded that either of the two methods could be used for calculating HCLPF capacities. 21 refs., 9 figs., 6 tabs
Estrada, J
1994-01-01
Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of sup 2 sup 1 sup 0 Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measureme...
Methods for Calculation of Geogenetic Depth
Institute of Scientific and Technical Information of China (English)
Liu Ruixun; Lü Guxian; Wang Fangzheng; Wei Changshan; Guo Chusun
2004-01-01
Some current methods for the calculation of the geogenetic depth are based on the hydrostatic model, it is induced that the depth in certain underground place is equal to the pressure divided by the specific weight of rock, on the assumption that the rock is hydrostatic and overlain by no other force but gravity. However, most of rock is in a deformation environment and non-hydrostatic state, especially in an orogenic belt, so that the calculated depth may be exaggerated in comparison with the actual depth according to the hydrostatic formula. In the finite slight deformation and elastic model, the relative actual depth value from the 3-axis strain data was obtained with the measurement of strain including that of superimposed tectonic forces but excluding that of time factor for the strain. If some data on the strain speed are obtained, the depth would be more realistically calculated according to the rheological model because the geological body often experiences long-term creep strains.
Thermal Bridges in Building Construction - Measurements and Calculations
DEFF Research Database (Denmark)
Rose, Jørgen
The thesis investigates detailed calculation methods for evaluating heat loss through building envelope constructions, or more specific, thermal bridges. First a detailed description of the calculation methods, i.e. both calculation programs and guidelines, for calculating typical thermal bridges...... in building envelope constructions is given. After this a validation of both programs and guidelines is presented. The validation is performed by comparing calculated U-values with Guarded Hot Box measurements. The last part of the thesis discusses the possibilities of utilising the results of detailed...
Risk calculation method for complex engineering system
Directory of Open Access Journals (Sweden)
Li-ping WANG
2011-09-01
Full Text Available This paper presents a rapid and simple risk calculation method for large and complex engineering systems, the simulated maximum entropy method (SMEM, which is based on integration of the advantages of the Monte Carlo and maximum entropy methods, thus avoiding the shortcoming of the slow convergence rate of the Monte Carlo method in risk calculation. Application of SMEM in the calculation of reservoir flood discharge risk shows that this method can make full use of the known information under the same conditions and obtain the corresponding probability distribution and the risk value. It not only greatly improves the speed, compared with the Monte Carlo method, but also provides a new approach for the risk calculation in large and complex engineering systems.
International Nuclear Information System (INIS)
The aim of this work is to elaborate a Monte Carlo programme which calculate the photoelectric efficiency of a planar high purity Ge detector for low energy photons. This programme calculate the auto absorption, the absorption in different media crossed by the photon and the intrinsic and total efficiencies. The results of this programme were very satisfactory since they reproduce the measured values in the two different cases of punctual and volumic sources. The result of the photoelectric efficiency calculation with this programme has been applied to determine the cross section of the 166-Er (n,2 n) 165-Er reaction induced by 14 MeV neutron, where only the measurement by x spectrometry is possible. The value obtained is concordant with the data given by the literature. 119 figs., 39 tabs., 96 refs. (F.M.)
International Nuclear Information System (INIS)
Method for determination f residual welding stresses making it possible to reduce uncertainty in calculational conditions for heat exchange of welding details with the environment and equipment through application of shell wall actual temperatures, changing in the course of welding, is proposed.Tubes of 12Kh18N10T steel were chosen for the method experimental verification. 5 refs., 5 figs., 1 tab
Methods of bone marrow dose calculation
International Nuclear Information System (INIS)
Several methods of bone marrow dose calculation for photon irradiation were analised. After a critical analysis, the author proposes the adoption, by the Instituto de Radioprotecao e Dosimetria/CNEN, of Rosenstein's method for dose calculations in Radiodiagnostic examinations and Kramer's method in case of occupational irradiation. It was verified by Eckerman and Simpson that for monoenergetic gamma emitters uniformly distributed within the bone mineral of the skeleton the dose in the bone surface can be several times higher than dose in skeleton. In this way, is also proposed the Calculation of tissue-air ratios for bone surfaces in some irradiation geometries and photon energies to be included in the Rosenstein's method for organ dose calculation in Radiodiagnostic examinations. (Author)
Eigenvalue translation method for mode calculations.
Gerck, E; Cruz, C H
1979-05-01
A new method is described for the first few modes calculations in a interferometer that has several advantages over the Allmat subroutine, the Prony method, and the Fox and Li method. In the illustrative results shown for some cases it can be seen that the eigenvalue translation method is typically 100-fold times faster than the usual Fox and Li method and ten times faster than Allmat.
Relaxation Method For Calculating Quantum Entanglement
Tucci, R R
2001-01-01
In a previous paper, we showed how entanglement of formation can be defined as a minimum of the quantum conditional mutual information (a.k.a. quantum conditional information transmission). In classical information theory, the Arimoto-Blahut method is one of the preferred methods for calculating extrema of mutual information. We present a new method akin to the Arimoto-Blahut method for calculating entanglement of formation. We also present several examples computed with a computer program called Causa Comun that implements the ideas of this paper.
Calculating reliability measures for ordinal data.
Gamsu, C V
1986-11-01
Establishing the reliability of measures taken by judges is important in both clinical and research work. Calculating the statistic of choice, the kappa coefficient, unfortunately is not a particularly quick and simple procedure. Two much-needed practical tools have been developed to overcome these difficulties: a comprehensive and easily understood guide to the manual calculation of the most complex form of the kappa coefficient, weighted kappa for ordinal data, has been written; and a computer program to run under CP/M, PC-DOS and MS-DOS has been developed. With simple modification the program will also run on a Sinclair Spectrum home computer.
International Nuclear Information System (INIS)
Direct measurement of the absolved dose to lung tissue from inhalation of radon and its progeny is not possible and must be calculated using dosimetric models, taking into consideration the several parameters upon which the dose calculation depends. To asses the dose due to inhalation of radon and its progeny, it is necessary to estimate the cumulative exposure. Historically, this has been done using WLM values estimated with measurements of radon concentration in air. The radon concentration in air varies significantly, however, in space with time, and the exposed individual is also constantly moving around. This makes it almost impossible to obtain a precise estimate of an individual's inhalation exposure. This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of 210 Pb, in subjects exposed to above-average radon and its progeny concentrations in their home environments. The measurements were performed in a whole body counter. With this technique, the exposed individuals become, in affect, their own samplers and dosimeters and the estimate of cumulative exposure is not affected by the variation of the atmospheric concentration of radon and its progeny in time and space. Forty individuals identified as living in homes with radon levels ranging from about 740 Bq/m3 to 150.000 Bq/m3 were measured. Also, additional 34 measurements were made on personnel from NYUMC/NIEM who live in a residential area surrounding the laboratory in which the levels of radon have been shown to be at below average values. To realize these measurements a methodology was developed to determine the subject's background, using a head phantom made with a cubic plastic container containing known amounts of potassium and calcium dissolved in four liters of water. The effective doses calculated from the in vivo measurements are compared to effective doses estimated, for the same
Reactor perturbation calculations by Monte Carlo methods
International Nuclear Information System (INIS)
Whilst Monte Carlo methods are useful for reactor calculations involving complicated geometry, it is difficult to apply them to the calculation of perturbation worths because of the large amount of computing time needed to obtain good accuracy. Various ways of overcoming these difficulties are investigated in this report, with the problem of estimating absorbing control rod worths particularly in mind. As a basis for discussion a method of carrying out multigroup reactor calculations by Monte Carlo methods is described. Two methods of estimating a perturbation worth directly, without differencing two quantities of like magnitude, are examined closely but are passed over in favour of a third method based on a correlation technique. This correlation method is described, and demonstrated by a limited range of calculations for absorbing control rods in a fast reactor. In these calculations control rod worths of between 1% and 7% in reactivity are estimated to an accuracy better than 10% (3 standard errors) in about one hour's computing time on the English Electric KDF.9 digital computer. (author)
Calculation of skid resistance from texture measurements
Directory of Open Access Journals (Sweden)
Andreas Ueckermann
2015-02-01
Full Text Available There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature, measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components: measurement of the pavement texture by means of an optical measuring system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented. The concept is applied to a laboratory device called Wehner/Schulze (W/S machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.
Comparison between measured and calculated neutron spectra in FCA assemblies
International Nuclear Information System (INIS)
The neutron spectra measured in FCA Assembly VI-2, VI-1 and V-2 are discussed, and are compared with the results by calculation. The data were obtained by measurements of proton-recoil counter and double scintillator methods. Calculations were made with cell-program SP-2000 and fine-group cross section library AGRI/2, and the spectra with 1950 groups and broadened 64 and 26 group were derived. The measured spectra in the energy range of 5 keV to 6 MeV were effectively compared with the calculational results, by using C/E values. There are large differences between the measured and the calculated spectra near the 430 keV oxygen and 29 keV iron resonances. The experimental and the calculated central fission rate ratios were also compared. (author)
Willow growing - Methods of calculation and profitability
International Nuclear Information System (INIS)
The calculation method presented here makes it possible to conduct profitability comparisons between annual and perennial crops and in addition take the planning situation into account. The method applied is a modified total step calculation. The difference between a traditional total step calculation and the modified version is the way in which payments and disbursements are taken into account over a period of several years. This is achieved by combining the present value method and the annuity method. The choice of interest rate has great bearing on the result in perennial calculations. The various components influencing the interest rate are analysed and factors relating to the establishment of the interest rate in different situations are described. The risk factor can be an important variable component of the interest rate calculation. Risk is also addressed from an approach in accordance with portfolio theory. The application of the methods sheds light on the profitability of Salix cultivation from the viewpoint of business economics, and also how different factors influence the profitability of Salix cultivation. Aspects studied are harvesting intervals, the importance of yield level, the competitiveness of Salix versus grain cultivation, the influence of income taxes on profitability etc. Methods for evaluation of activities concerning cultivation of a perennial crop are described and also involve the application of nitrogen fertilization to Salix cultivation. Studies have been performed using these methods to look into nitrogen fertilizer profitability in Salix cultivation during the first rotation period. Nitrogen fertilizer profitability has been investigated involving both production functions and cost calculations, taking the year fertilization into consideration. 72 refs., 2 figs., 52 tabs
A method for tokamak neutronics calculations
International Nuclear Information System (INIS)
This paper presents a new method for neutron transport calculation in tokamak fusion reactors. The computational procedure is based on the solution of the even-parity transport equation in a toroidal geometry. The angular neutron distribution is treated by even-parity spherical harmonic expansion, while the spatial dependence is approximated by using R-function finite elements that are defined for regions of arbitrary geometric shape. In order to test the method, calculation of a simplified tokamak model is carried out. The results are compared with the results from the literature and for the same order of accuracy a reduction of the number of spatial unknowns is shown. (author)
Calculation methods for compressible turbulent boundary layers
Bushnell, D. M.; Cary, A. M., Jr.; Harris, J. E.
1976-01-01
Calculation procedures for non-reacting compressible two- and three-dimensional turbulent boundary layers were reviewed. Integral, transformation and correlation methods, as well as finite difference solutions of the complete boundary layer equations summarized. Alternative numerical solution procedures were examined, and both mean field and mean turbulence field closure models were considered. Physics and related calculation problems peculiar to compressible turbulent boundary layers are described. A catalog of available solution procedures of the finite difference, finite element, and method of weighted residuals genre is included. Influence of compressibility, low Reynolds number, wall blowing, and pressure gradient upon mean field closure constants are reported.
Pressure Profile Calculation with Mesh Ewald Methods.
Sega, Marcello; Fábián, Balázs; Jedlovszky, Pál
2016-09-13
The importance of calculating pressure profiles across liquid interfaces is increasingly gaining recognition, and efficient methods for the calculation of long-range contributions are fundamental in addressing systems with a large number of charges. Here, we show how to compute the local pressure contribution for mesh-based Ewald methods, retaining the typical N log N scaling as a function of the lattice nodes N. This is a considerable improvement on existing methods, which include approximating the electrostatic contribution using a large cutoff and the, much slower, Ewald calculation. As an application, we calculate the contribution to the pressure profile across the water/vapor interface, coming from different molecular layers, both including and removing the effect of thermal capillary waves. We compare the total pressure profile with the one obtained using the cutoff approximation for the calculation of the stresses, showing that the stress distributions obtained using the Harasima and Irving-Kirkwood path are quite similar and shifted with respect to each other at most 0.05 nm. PMID:27508458
Lee, S G; Bitter, M; Förster, E; Hill, K W; Hoelzer, G; Jung, Y S; Wehrhan, O
2003-01-01
This paper describes a new method for the simultaneous measurement of the integrated reflectivity of a crystal for multiple orders of reflection at a predefined Bragg angle. The technique is demonstrated with a mica crystal for Bragg angles of 43 sup o , 47 sup o , and 50 sup o. The measured integrated reflectivity for Bragg reflections up to the 24th order is compared with new theoretical predictions, which are also presented in this paper.
Covariant method for calculating helicity amplitudes
International Nuclear Information System (INIS)
We present an alternative approach for calculating helicity amplitudes for processes involving both massless and massive fermions. With this method one can easily obtain covariant expressions for the helicity amplitudes. The final expressions involve only four-vector products and are independent of the basis for γ matrices or specific form of the spinors. We use the method to obtain the helicity amplitudes for several processes involving top quark production. copyright 1996 The American Physical Society
Calculation of Expected Shortfall for Measuring Risk and Its Applications
Institute of Scientific and Technical Information of China (English)
阎春宁; 余鹏; 黄养新
2005-01-01
Expected shortfall(ES) is a new method to measure market risk. In this paper, an example was presented to illustrate that the ES is coherent but value-at-risk(VaR) is not coherent. Three formulas for calculating the ES based on historical simulation method, normal method and GARCH method were derived. Further, a numerical experiment on optimizing portfolio using ES was provided.
Energy Technology Data Exchange (ETDEWEB)
Henniger, Juergen; Jakobi, Christoph [Technische Univ. Dresden (Germany). Arbeitsgruppe Strahlungsphysik (ASP)
2015-07-01
From a mathematical point of view Monte Carlo methods are the numerical solution of certain integrals and integral equations using a random experiment. There are several advantages compared to the classical stepwise integration. The time required for computing increases for multi-dimensional problems only moderately with increasing dimension. The only requirements for the integral kernel are its capability of being integrated in the considered integration area and the possibility of an algorithmic representation. These are the important properties of Monte Carlo methods that allow the application in every scientific area. Besides that Monte Carlo algorithms are often more intuitive than conventional numerical integration methods. The contribution demonstrates these facts using the example of dead time corrections for counting measurements.
Acceleration methods and models in Sn calculations
International Nuclear Information System (INIS)
In some neutron transport problems solved by the discrete ordinate method, it is relatively common to observe some particularities as, for example, negative fluxes generation, slow and insecure convergences and solution instabilities. The commonly used models for neutron flux calculation and acceleration methods included in the most used codes were analyzed, in face of their use in problems characterized by a strong upscattering effect. Some special conclusions derived from this analysis are presented as well as a new method to perform the upscattering scaling for solving the before mentioned problems in this kind of cases. This method has been included in the DOT3.5 code (two dimensional discrete ordinates radiation transport code) generating a new version of wider application. (Author)
DEFF Research Database (Denmark)
Diamond, J. M.
1965-01-01
A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test.......A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test....
Methods for calculating radiation attenuation in shields
International Nuclear Information System (INIS)
In recent years the development of high-speed digital computers of large capacity has revolutionized the field of reactor shield design. For compact special-purpose reactor shields, Monte-Carlo codes in two- and three dimensional geometries are now available for the proper treatment of both the neutron and gamma- ray problems. Furthermore, techniques are being developed for the theoretical optimization of minimum-weight shield configurations for this type of reactor system. In the design of land-based power reactors, on the other hand, there is a strong incentive to reduce the capital cost of the plant, and economic considerations are also relevant to reactors designed for merchant ship propulsion. In this context simple methods are needed which are economic in their data input and computing time requirements and which, at the same time, are sufficiently accurate for design work. In general the computing time required for Monte-Carlo calculations in complex geometry is excessive for routine design calculations and the capacity of the present codes is inadequate for the proper treatment of large reactor shield systems in three dimensions. In these circumstances a wide range of simpler techniques are currently being employed for design calculations. The methods of calculation for neutrons in reactor shields fall naturally into four categories: Multigroup diffusion theory; Multigroup diffusion with removal sources; Transport codes; and Monte Carlo methods. In spite of the numerous Monte- Carlo techniques which are available for penetration and back scattering, serious problems are still encountered in practice with the scattering of gamma rays from walls of buildings which contain critical facilities and also concrete-lined discharge shafts containing irradiated fuel elements. The considerable volume of data in the unclassified literature on the solution of problems of this type in civil defence work appears not to have been evaluated for reactor shield design. In
Methods of Measuring Competitiveness
Podaºcã Raluca
2012-01-01
Any approach to measuring competitiveness and competitive advantages must take account of one hand of the covered analysis: microeconomic, mezoeconomic, macroeconomic, and on the other hand that they are the result of many variables that are interconditioned directly or indirectly. Measurement methods attempt to quantify the impact of competitiveness and the variables considered relevant. Among all methods of measuring global competitiveness stands Global Competitiveness Index and Economic Fr...
The matrix method to calculate page rank
Directory of Open Access Journals (Sweden)
H. Barboucha, M. Nasri
2014-06-01
Full Text Available Choosing the right keywords is relatively easy, whereas getting a high PageRank is more complicated. The index Page Rank is what defines the position in the result pages of search engines (for Google of course, but the other engines are now using more or less the same kind of algorithm. It is therefore very important to understand how this type of algorithm functions to hope to appear on the first page of results (the only page read in 95 % of cases or at least be among the first. We propose in this paper to clarify the operation of this algorithm using a matrix method and a JavaScript program enabling to experience this type of analysis. It is of course a simplified version, but it can add value to the website and achieve a high ranking in the search results and reach a larger customer base. The interest is to disclose an algorithm to calculate the relevance of each page. This is in fact a mathematical algorithm based on a web graph. This graph is formed of all the web pages that are modeled by nodes, and hyperlinks that are modeled by arcs.
Nuclear data and multigroup methods in fast reactor calculations
International Nuclear Information System (INIS)
The work deals with fast reactor multigroup calculations, and the efficient treatment of basic nuclear data, which serves as raw material for the calculations. Its purpose is twofold: to build a computer code system that handles a large, detailed library of basic neutron cross section data, (such as ENDF/B-III) and yields a compact set of multigroup cross sections for reactor calculations; to use the code system for comparative analysis of different libraries, in order to discover basic uncertainties that still exist in the measurement of neutron cross sections, and to determine their influence upon uncertainties in nuclear calculations. A program named NANICK which was written in two versions is presented. The first handles the American basic data library, ENDF/B-III, while the second handles the German basic data library, KEDAK. The mathematical algorithm is identical in both versions, and only the file management is different. This program calculates infinitely diluted multigroup cross sections and scattering matrices. It is complemented by the program NASIF that calculates shielding factors from resonance parameters. Different versions of NASIF were written to handle ENDF/B-III or KEDAK. New methods for evaluating in reactor calculations the long term behavior of the neutron flux as well as its fine structure are described and an efficient calculation of the shielding factors from resonance parameters is offered. (B.G.)
Calculation of skid resistance from texture measurements
Andreas Ueckermann; Dawei Wang; Markus Oeser; Bernhard Steinauer
2015-01-01
There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors li...
METHODS OF CALCULATING THE ELECTRONIC AND ATOMIC STRUCTURES OF INTERFACES
Sutton, A
1985-01-01
Methods of calculating the electronic and atomic structures of interfaces are described. An introduction to pseudopotentials and LCAO methods is given. Methods of calculating the electronic structure of an interface with a given atomic structure are considered. The feasibility of total energy calculations, in which the atomic and electronic structures are calculated simultaneously, is discussed.
Overview of multifluid-flow-calculation methods
International Nuclear Information System (INIS)
Two categories of numerical methods which may be useful in multiphase flow research are discussed. The first category includes methods which are specifically intended for accurate computation of discontinuities, such as the method of characteristics, particle-in-cell method, flux-corrected transport, and random choice methods. Methods in this category could be applied to research on rocket exhaust plumes and interior ballistics. The second category includes methods for smooth, subsonic flows, such as fractional step methods, semi-implicit method, and methods which treat convection implicitly. The subsonic flow methods could be of interest for ice flows
Deconstructing Calculation Methods, Part 3: Multiplication
Thompson, Ian
2008-01-01
In this third of a series of four articles, the author deconstructs the primary national strategy's approach to written multiplication. The approach to multiplication, as set out on pages 12 to 15 of the primary national strategy's "Guidance paper" "Calculation" (DfES, 2007), is divided into six stages: (1) mental multiplication using…
Methods for calculating anisotropic transfer cross sections
International Nuclear Information System (INIS)
The Legendre moments of the group transfer cross section, which are widely used in the numerical solution of the transport calculation can be efficiently and accurately constructed from low-order (K = 1--2) successive partial range moments. This is convenient for the generation of group constants. In addition, a technique to obtain group-angle correlation transfer cross section without Legendre expansion is presented. (author)
Monte Carlo method application to shielding calculations
International Nuclear Information System (INIS)
CANDU spent fuel discharged from the reactor core contains Pu, so it must be stressed in two directions: tracing for the fuel reactivity in order to prevent critical mass formation and personnel protection during the spent fuel manipulation. The basic tasks accomplished by the shielding calculations in a nuclear safety analysis consist in dose rates calculations in order to prevent any risks both for personnel protection and impact on the environment during the spent fuel manipulation, transport and storage. To perform photon dose rates calculations the Monte Carlo MORSE-SGC code incorporated in SAS4 sequence from SCALE system was used. The paper objective was to obtain the photon dose rates to the spent fuel transport cask wall, both in radial and axial directions. As source of radiation one spent CANDU fuel bundle was used. All the geometrical and material data related to the transport cask were considered according to the shipping cask type B model, whose prototype has been realized and tested in the Institute for Nuclear Research Pitesti. (authors)
Computational methods for probability of instability calculations
Wu, Y.-T.; Burnside, O. H.
1990-01-01
This paper summarizes the development of the methods and a computer program to compute the probability of instability of a dynamic system than can be represented by a system of second-order ordinary linear differential equations. Two instability criteria based upon the roots of the characteristics equation or Routh-Hurwitz test functions are investigated. Computational methods based on system reliability analysis methods and importance sampling concepts are proposed to perform efficient probabilistic analysis. Numerical examples are provided to demonstrate the methods.
Calculation Method for Normal Inducedlongitudinal Voltage on Pilot Cable
Directory of Open Access Journals (Sweden)
Abdelaziz B.M. Kamel,
2014-09-01
Full Text Available In this paper a full study and detailed calculations of the induced voltage in pilot cables are carried out. First an introduction showing the importance of the induced voltage and its effect in pilot cables. The first calculation method Flat Formation. The second calculation method Trefoil Formation. Then the results obtained for both methods and compared. Finally a conclusion is conduct.
Calculating isotopic fractionation from atmospheric measurements at various scales
International Nuclear Information System (INIS)
In this paper we describe some new approaches for calculating isotopic discrimination from atmospheric measurements of CO2 and 13C. We introduce a framework that is more flexible than the traditional 'Keeling plot' two end-member mixing model, because it allows for the explicit specification of the background values of both CO2 and 13C. This approach is necessary for evaluating time series for which one can be certain that the Keeling plot requirement of stable background is violated. We also discuss a robust method for curve fitting and for estimating uncertainty of the fitting parameters. In addition to accounting for the uncertainty associated with measurements, we also account for the uncertainty associated with the appropriateness of the analytical model to the data. Our analysis suggests that uncertainty in calculated source signatures is more strongly related to the appropriateness of the model to the data than to the analytical precision of CO2 and 13C measurements. Relative to our approach, other approaches tend to underestimate the uncertainty in the fitted parameters. There can be substantial uncertainty in slopes and intercepts (two per mil or more) even if R2 is greater than 0.98. In addition, we note that fitting methods not accounting for uncertainty in both x and y result in systematic biases in the fitted parameters. Finally, we discuss the interpretation of the apparent isotopic source signature when this is a composite of several sources
Calculated and measured fields in superferric wiggler magnets
Energy Technology Data Exchange (ETDEWEB)
Blum, E.B.; Solomon, L. [Brookhaven National Lab., Upton, NY (United States)
1995-02-01
Although Klaus Halbach is widely known and appreciated as the originator of the computer program POISSON for electromagnetic field calculation, Klaus has always believed that analytical methods can give much more insight into the performance of a magnet than numerical simulation. Analytical approximations readily show how the different aspects of a magnet`s design such as pole dimensions, current, and coil configuration contribute to the performance. These methods yield accuracies of better than 10%. Analytical methods should therefore be used when conceptualizing a magnet design. Computer analysis can then be used for refinement. A simple model is presented for the peak on-axis field of an electro-magnetic wiggler with iron poles and superconducting coils. The model is applied to the radiator section of the superconducting wiggler for the BNL Harmonic Generation Free Electron Laser. The predictions of the model are compared to the measured field and the results from POISSON.
Calculation of radon concentration in water by toluene extraction method
Energy Technology Data Exchange (ETDEWEB)
Saito, Masaaki [Tokyo Metropolitan Isotope Research Center (Japan)
1997-02-01
Noguchi method and Horiuchi method have been used as the calculation method of radon concentration in water. Both methods have two problems in the original, that is, the concentration calculated is changed by the extraction temperature depend on the incorrect solubility data and the concentration calculated are smaller than the correct values, because the radon calculation equation does not true to the gas-liquid equilibrium theory. However, the two problems are solved by improving the radon equation. I presented the Noguchi-Saito equation and the constant B of Horiuchi-Saito equation. The calculating results by the improved method showed about 10% of error. (S.Y.)
COSTS CALCULATION OF TARGET COSTING METHOD
Directory of Open Access Journals (Sweden)
Sebastian UNGUREANU
2014-06-01
Full Text Available Cost information system plays an important role in every organization in the decision making process. An important task of management is ensuring control of the operations, processes, sectors, and not ultimately on costs. Although in achieving the objectives of an organization compete more control systems (production control, quality control, etc., the cost information system is important because monitors results of the other. Detailed analysis of costs, production cost calculation, quantification of losses, estimate the work efficiency provides a solid basis for financial control. Knowledge of the costs is a decisive factor in taking decisions and planning future activities. Managers are concerned about the costs that will appear in the future, their level underpinning the supply and production decisions as well as price policy. An important factor is the efficiency of cost information system in such a way that the information provided by it may be useful for decisions and planning of the work.
49 CFR 531.6 - Measurement and calculation procedures.
2010-10-01
... the Act and set forth in 40 CFR part 600. (b) A manufacturer that is eligible to elect a model year in... 49 Transportation 6 2010-10-01 2010-10-01 false Measurement and calculation procedures. 531.6... STANDARDS § 531.6 Measurement and calculation procedures. (a) The average fuel economy of all...
49 CFR 533.6 - Measurement and calculation procedures.
2010-10-01
... 49 Transportation 6 2010-10-01 2010-10-01 false Measurement and calculation procedures. 533.6 Section 533.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... Measurement and calculation procedures. (a) Any reference to a class of light trucks manufactured by...
Fast variation method for elastic strip calculation.
Biryukov, Sergey V
2002-05-01
A new, fast, variation method (FVM) for determining an elastic strip response to stresses arbitrarily distributed on the flat side of the strip is proposed. The remaining surface of the strip may have an arbitrary form, and it is free of stresses. The FVM, as well as the well-known finite element method (FEM), starts with the variational principle. However, it does not use the meshing of the strip. A comparison of FVM results with the exact analytical solution in the special case of shear stresses and a rectangular strip demonstrates an excellent agreement.
Transportation channels calculation method in MATLAB
International Nuclear Information System (INIS)
Output devices and charged particles transport channels are necessary components of any modern particle accelerator. They differ both in sizes and in terms of focusing elements depending on particle accelerator type and its destination. A package of transport line designing codes for magnet optical channels in MATLAB environment is presented in this report. Charged particles dynamics in a focusing channel can be studied easily by means of the matrix technique. MATLAB usage is convenient because its information objects are matrixes. MATLAB allows the use the modular principle to build the software package. Program blocks are small in size and easy to use. They can be executed separately or commonly. A set of codes has a user-friendly interface. Transport channel construction consists of focusing lenses (doublets and triplets). The main of the magneto-optical channel parameters are total length and lens position and parameters of the output beam in the phase space (channel acceptance, beam emittance - beam transverse dimensions, particles divergence and image stigmaticity). Choice of the channel operation parameters is based on the conditions for satisfying mutually competing demands. And therefore the channel parameters calculation is carried out by using the search engine optimization techniques.
Deconstructing Calculation Methods, Part 4: Division
Thompson, Ian
2008-01-01
In the final article of a series of four, the author deconstructs the primary national strategy's approach to written division. The approach to division is divided into five stages: (1) mental division using partition; (2) short division of TU / U; (3) "expanded" method for HTU / U; (4) short division of HTU / U; and (5) long division. [For part…
Investigation of Calculation Techniques of Finite Difference Method
Directory of Open Access Journals (Sweden)
Audrius Krukonis
2011-03-01
Full Text Available Finite difference method used for microstrip transmission line analysis is considered in this article. Paper mainly deals with iterative and bound matrix calculation techniques of finite difference method. Mathematical model for microstrip transmission line electrical potential calculations using both techniques is described. Results of characteristic impedance calculation using iterative and bound matrix techniques are presented and analyzed.Article in Lithuanian
Calculation methods for neutron radiography spatial resolution
International Nuclear Information System (INIS)
Spatial resolution is an important parameter for neutron radiography facility. In this paper, different methods to define the spatial resolution,such as point spread function (PSF), line spread function (LSF), edge spread function (ESF) and modulation transfer function (MTF), are analyzed and compared. MTF turns out to be the best, as it is derived from the linear system theory in a given frequency domain, and gives the maximum amount of useful information on system signal modulation. (authors)
Progress and prospects of calculation methods for radiation shielding
International Nuclear Information System (INIS)
Progress in calculation methods for radiation shielding are reviewed based on the activities of research committees related to radiation shielding fields established in the Atomic Energy Society of Japan. A technological roadmap for the field of radiation shielding; progress and prospects for specific shielding calculation methods such as the Monte Carlo, discrete ordinate Sn transport, and simplified methods; and shielding experiments used to validate calculation methods are presented in this paper. (author)
MEASURING OF COMPLEX STRUCTURE TRANSFER FUNCTION AND CALCULATING OF INNER SOUND FIELD
Institute of Scientific and Technical Information of China (English)
Chen Yuan; Huang Qibai; Shi Hanmin
2005-01-01
In order to measure complex structure transfer function and calculate inner sound field, transfer function of integration is mentioned. By establishing virtual system, transfer function of integration can be measured and the inner sound field can also be calculated. In the experiment, automobile body transfer function of integration is measured and experimental method of establishing virtual system is very valid.
Nodal methods in numerical reactor calculations
International Nuclear Information System (INIS)
The present work describes the antecedents, developments and applications started in 1972 with Prof. Hennart who was invited to be part of the staff of the Nuclear Engineering Department at the School of Physics and Mathematics of the National Polytechnic Institute. Since that time and up to 1981, several master theses based on classical finite element methods were developed with applications in point kinetics and in the steady state as well as the time dependent multigroup diffusion equations. After this period the emphasis moved to nodal finite elements in 1, 2 and 3D cartesian geometries. All the thesis were devoted to the numerical solution of the neutron multigroup diffusion and transport equations, few of them including the time dependence, most of them related with steady state diffusion equations. The main contributions were as follows: high order nodal schemes for the primal and mixed forms of the diffusion equations, block-centered finite-differences methods, post-processing, composite nodal finite elements for hexagons, and weakly and strongly discontinuous schemes for the transport equation. Some of these are now being used by several researchers involved in nuclear fuel management. (Author)
A new method for calculation of an air quality index
Energy Technology Data Exchange (ETDEWEB)
Ilvessalo, P. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.
1995-12-31
Air quality measurement programs in Finnish towns have expanded during the last few years. As a result of this it is more and more difficult to make use of all the measured concentration data. Citizens of Finnish towns are nowadays taking more of an interest in the air quality of their surroundings. The need to describe air quality in a simplified form has increased. Air quality indices permit the presentation of air quality data in such a way that prevailing conditions are more easily understandable than when using concentration data as such. Using an air quality index always means that some of the information about concentrations of contaminants in the air will be lost. How much information is possible to extract from a single index number depends on the calculation method. A new method for the calculation of an air quality index has been developed. This index always indicates the overstepping of an air quality guideline level. The calculation of this air quality index is performed using the concentrations of all the contaminants measured. The index gives information both about the prevailing air quality and also the short-term trend. It can also warn about the expected exceeding of guidelines due to one or several contaminants. The new index is especially suitable for the real-time monitoring and notification of air quality values. The behaviour of the index was studied using material from a measurement period in the spring of 1994 in Kaepylae, Helsinki. Material from a pre-operational period in the town of Oulu was also available. (author)
Score Calculation in Informatics Contests Using Multiple Criteria Decision Methods
Directory of Open Access Journals (Sweden)
Jurate SKUPIENE
2011-04-01
Full Text Available The Lithuanian Informatics Olympiad is a problem solving contest for high school students. The work of each contestant is evaluated in terms of several criteria, where each criterion is measured according to its own scale (but the same scale for each contestant. Several jury members are involved in the evaluation. This paper analyses the problem how to calculate the aggregated score for whole submission in the above mentioned situation. The chosen methodology for solving this problem is Multiple Criteria Decision Analysis (MCDA. The outcome of this paper is the score aggregation method proposed to be applied in LitIO developed using MCDA approaches.
Simulation of FEL pulse length calculation with THz streaking method
Energy Technology Data Exchange (ETDEWEB)
Gorgisyan, I., E-mail: ishkhan.gorgisyan@psi.ch [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne (Switzerland); Ischebeck, R.; Prat, E.; Reiche, S. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Rivkin, L. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne (Switzerland); Juranić, P., E-mail: ishkhan.gorgisyan@psi.ch [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)
2016-04-02
Simulation of THz streaking of photoelectrons created by X-ray pulses from a free-electron laser and reconstruction of the free-electron laser pulse lengths. Having accurate and comprehensive photon diagnostics for the X-ray pulses delivered by free-electron laser (FEL) facilities is of utmost importance. Along with various parameters of the photon beam (such as photon energy, beam intensity, etc.), the pulse length measurements are particularly useful both for the machine operators to measure the beam parameters and monitor the stability of the machine performance, and for the users carrying out pump–probe experiments at such facilities to better understand their measurement results. One of the most promising pulse length measurement techniques used for photon diagnostics is the THz streak camera which is capable of simultaneously measuring the lengths of the photon pulses and their arrival times with respect to the pump laser. This work presents simulations of a THz streak camera performance. The simulation procedure utilizes FEL pulses with two different photon energies in hard and soft X-ray regions, respectively. It recreates the energy spectra of the photoelectrons produced by the photon pulses and streaks them by a single-cycle THz pulse. Following the pulse-retrieval procedure of the THz streak camera, the lengths were calculated from the streaked spectra. To validate the pulse length calculation procedure, the precision and the accuracy of the method were estimated for streaking configuration corresponding to previously performed experiments. The obtained results show that for the discussed setup the method is capable of measuring FEL pulses with about a femtosecond accuracy and precision.
Large-scale atomic calculations using variational methods
International Nuclear Information System (INIS)
Atomic properties, such as radiative lifetimes, hyperfine structures and isotope shift, have been studied both theoretically and experimentally. Computer programs which calculate these properties from multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) wave functions have been developed and tested. To study relativistic effects, a program which calculates hyperfine structures from multiconfiguration Dirac-Fock (MCDF) wave functions has also been written. A new method of dealing with radial non-orthogonalities in transition matrix elements has been investigated. This method allows two separate orbital sets to be used for the initial and final states, respectively. It is shown that, once the usual orthogonality restrictions have been overcome, systematic MCHF calculations are able to predict oscillator strengths in light atoms with high accuracy. In connection with recent high-power laser experiments, time-dependent calculations of the atomic response to intense laser fields have been performed. Using the frozen-core approximation, where the atom is modeled as an active electron moving in the average field of the core electrons and the nucleus, the active electron has been propagated in time under the influence of the laser field. Radiative lifetimes and hyperfine structures of excited states in sodium and silver have been experimentally determined using time-resolved laser spectroscopy. By recording the fluorescence light decay following laser excitation in the vacuum ultraviolet spectral region, the radiative lifetimes and hyperfine structures of the 7p2P states in silver have been measured. The delayed-coincidence technique has been used to make very accurate measurements of the radiative lifetimes and hyperfine structures of the lowest 2P states in sodium and silver. 77 refs, 2 figs, 14 tabs
Martian Radiation Environment: Model Calculations and Recent Measurements with "MARIE"
Saganti, P. B.; Cucinotta, F. A.; zeitlin, C. J.; Cleghorn, T. F.
2004-01-01
The Galactic Cosmic Ray spectra in Mars orbit were generated with the recently expanded HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations are compared with the first eighteen months of measured data from the MARIE (Martian Radiation Environment Experiment) instrument onboard the 2001 Mars Odyssey spacecraft that is currently in Martian orbit. The dose rates observed by the MARIE instrument are within 10% of the model calculated predictions. Model calculations are compared with the MARIE measurements of dose, dose-equivalent values, along with the available particle flux distribution. Model calculated particle flux includes GCR elemental composition of atomic number, Z = 1-28 and mass number, A = 1-58. Particle flux calculations specific for the current MARIE mapping period are reviewed and presented.
Measurements and Terminology of Different Measure Methods
Institute of Scientific and Technical Information of China (English)
FANG Fang; ZHANG Wei-yuan; ZHANG Wen-bin
2005-01-01
Body measuring is very important for garment sizing and pattern making. In this paper, we study the difference of the landmarks between the traditional method and 3D scanner and we also select the 19 circumference measurements,29 height and length measurements, 18 breadth and depth measurements and 3 other measurements, which are quite important in fashion body measuring, to compare the terminology of them in these two measuring method. 3D scanners seem better than the traditional method on these aspects, which are the number of measurements, speed,privacy and data accuracy, but they are limited on measuring posture. And there is no uniform standard for the scanners and the definitions of the measurements in the scanners are diversified.
Quantum Monte Carlo diagonalization method as a variational calculation
Energy Technology Data Exchange (ETDEWEB)
Mizusaki, Takahiro; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Honma, Michio
1997-05-01
A stochastic method for performing large-scale shell model calculations is presented, which utilizes the auxiliary field Monte Carlo technique and diagonalization method. This method overcomes the limitation of the conventional shell model diagonalization and can extremely widen the feasibility of shell model calculations with realistic interactions for spectroscopic study of nuclear structure. (author)
Institute of Scientific and Technical Information of China (English)
方秀成; 孙淑琴; 王应吉; 林君
2015-01-01
提出一种测量激发场垂直于地磁场分量的测量方法：应用固定线圈电磁感应法测量激发场，应用磁通门传感器测量地磁场，通过矢量运算求解激发场垂直于地磁场的分量。制作了激发场测量装置，通过对比激发场的径向分量和轴向分量的理论计算值和实测值，验证测量装置有效性。分析固定点处激发场垂直于地磁场的分量受线圈布设方向的影响，推导出固定点处激发场垂直于地磁场的分量取最大值时线圈布设角度求解方法，为实际探测线圈布设方向提供理论指导。%Magnetic field component values,which is vertical to the geomagnetic field is put forward:the fixed coils electromagnetic induction method is adopted to detect the magnetic field,flux-gate sensor method is adopted to detect geomagnetic field ,the magnetic field’s component values,which is vertical to the geomagnetic field,is calculated through the vector calculation. The magnetic field detection device is made. By comparing theoretical calculation with actual measurement of magnetic field’s radial component values and axial component values,the magnetic field detection device is proved to be effective. The influnence,which is caused by the excitation direction of coil changed,to a fixed point’s magnetic field component values,which is vertical to the geomagnetic field,is analyzed. The method to calculate the excitation coils’best direction is put forward. In this direction,a fixed point’s magnetic field component values,which is vertical to the geomagnetic field ,is the biggest. As a result,it gives a theory guidence in the specific detection.
The TAB method for numerical calculation of spray droplet breakup
Orourke, P. J.; Amsden, A. A.
A short history is given of the major milestones in the development of the stochastic particle method for calculating liquid fuel sprays. The most recent advance has been the discovery of the importance of drop breakup in engine sprays. A new method, called TAB, for calculating drop breakup is presented. Some theoretical properties of the method are derived; its numerical implementation in the computer program KIVA is described; and comparisons are presented between TAB-method calculations and experiments and calculations using another breakup model.
Study on increasing calculation precision and convergence speed of streamline strip element method
Institute of Scientific and Technical Information of China (English)
彭艳; 刘宏民
2004-01-01
The calculation precision and convergence speed of streamline strip element method are increased by using the method whose initial value of the exit lateral displacement is determined with strip element variation method, and the accurate tension lateral distribution model is adopted based on the original third power spline function streamline strip element method. The basic theory of the strip element method is developed. The calculated results by the improved streamline strip element method and the original streamline strip element method are compared with the measured results, showing that the calculated results of the improved method are in good agreement with the measured results.
The Impact of Harmonics Calculation Methods on Power Quality Assessment in Wind Farms
DEFF Research Database (Denmark)
Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth
2010-01-01
Different methods of calculating harmonics in measurements obtained from offshore wind farms are shown in this paper. Appropriate data processing methods are suggested for harmonics with different origin and nature. Enhancements of discrete Fourier transform application in order to reduce...... measurement data processing errors are proposed and compared with classical methods. Comparison of signal processing methods for harmonic studies is presented and application dependent on harmonics origin and nature recommended. Certain aspects related to magnitude and phase calculation in stationary...... measurement data are analysed and described. Qualitative indices of measurement data harmonic analysis in order to assess the calculation accuracy are suggested and used....
Methods of speed measurement. Geschwindigkeitsmessverfahren
Energy Technology Data Exchange (ETDEWEB)
Baeumer, K.; Rath, K.; Rogge, H.; Wiegand, H.
1990-09-27
In a method, i.e. the operation of a device for contactless measurement of speeds, speed-time curves and decay frequencies in liquid jets and flames two light beams emitted by strong light source are focussed in such a way in the measured volume of a fluid layer or flame layer that the light transmission in the measured volume can be measured at a focal distance
A Damping Characteristics Calculation Method of Metal Dry Friction Isolators
Institute of Scientific and Technical Information of China (English)
JIANG Hong-yuan; HAO De-gang; XIA Yu-hong; ULANOV A M; PONOMAREV Yu K
2008-01-01
The dry friction ring-type vibration isolator is considered as an isotropic continuous medium. A method of dry friction hysteresis loop calculation is proposed based on friction force analysis of contact beam. The friction force is modeled as an equivalent distributed moment to use the finite element method (FEM) to calculate the dry friction vibration isolator hysteresis loop, so the damping characteristics can be obtained. A comparison of the hysteresis loop calculation results and the experimental results shows the average relative error is 2.7%, it proves the calculation method is feasible.
Comments on Simplified Calculation Method for Fire Exposed Concrete Columns
DEFF Research Database (Denmark)
Hertz, Kristian Dahl
1998-01-01
The author has developed new simplified calculation methods for fire exposed columns. Methods, which are found In ENV 1992-1-2 chapter 4.3 and in proposal for Danish code of Practise DS411 chapter 9. In the present supporting document the methods are derived and 50 eccentrically loaded fire exposed...... columns are calculated and compared to results of full-scale tests. Furthermore 500 columns are calculated in order to present each test result related to a variation of the calculation in time of fire resistance....
Directory of Open Access Journals (Sweden)
Forkapić S.
2006-01-01
Full Text Available Several important international scientific organizations have designated radon as a carcinogenic and serious health problem. As a chemically inert gas, it is easily released from soil, building materials, and water, to emanate to the atmosphere. Since 1992, Laboratory for Nuclear Physics of the Department of Physics, Faculty of Sciences in Novi Sad has been involved in measurements of radon concentration in air, using several different techniques. Last year, systematic radon measurements in drinking waters began, too. The work presented here gives a survey and discussion of the results of the both series of measurements.
Method for calculating annual energy efficiency improvement of TV sets
Energy Technology Data Exchange (ETDEWEB)
Varman, M. [Department of Mechanical Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Mahlia, T.M.I. [Department of Mechanical Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)]. E-mail: indra@um.edu.my; Masjuki, H.H. [Department of Mechanical Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)
2006-10-15
The popularization of 24 h pay-TV, interactive video games, web-TV, VCD and DVD are poised to have a large impact on overall TV electricity consumption in the Malaysia. Following this increased consumption, energy efficiency standard present a highly effective measure for decreasing electricity consumption in the residential sector. The main problem in setting energy efficiency standard is identifying annual efficiency improvement, due to the lack of time series statistical data available in developing countries. This study attempts to present a method of calculating annual energy efficiency improvement for TV set, which can be used for implementing energy efficiency standard for TV sets in Malaysia and other developing countries. Although the presented result is only an approximation, definitely it is one of the ways of accomplishing energy standard. Furthermore, the method can be used for other appliances without any major modification.
Evolution of calculation methods taking into account severe accidents
International Nuclear Information System (INIS)
During the first decade of PWRs operation in France the calculation methods used for design and operation have improved very much. This paper gives a general analysis of the calculation methods evolution in parallel with the evolution of safety approach concerning PWRs. Then a comprehensive presentation of principal calculation tools is presented as applied during the past decade. An effort is done to predict the improvements in near future
Hotel Competitiveness Measurement Methods
Katalin Juhasz-Dora
2015-01-01
Competitiveness is becoming a very common expression used in business administration. The definition and its application still raises some questions due to the complexity of its meaning. The role of the measurement of competitiveness and its effect on performance and profitability is increasing in the field of hospitality and tourism as well. The measurement of hotel competitiveness is a current issue in business life due to globalization, sharing economy and the change in the consumber habit...
A method for calculating the productivity of cable communications networks
Shulikin, S. N.; Shulikina, M. S.; Maryin, S. S.; Vinogradova, D. V.; Zavgorodnyaya, M. E.
2016-04-01
A probabilistic-mathematical instrument was used to develop a method for calculating the productivity of a cable line. The effect of deviation of factors from data of recording devices was determined when identifying random stream characteristics. The developed method was used to perform predictive calculation of the productivity of the modern cable communication line.
Calculation methods for compressible turbulent boundary layers, 1976
Bushnell, D. M.; Cary, A. M., Jr.; Harris, J. E.
1977-01-01
Equations and closure methods for compressible turbulent boundary layers are discussed. Flow phenomena peculiar to calculation of these boundary layers were considered, along with calculations of three dimensional compressible turbulent boundary layers. Procedures for ascertaining nonsimilar two and three dimensional compressible turbulent boundary layers were appended, including finite difference, finite element, and mass-weighted residual methods.
A New Method for Calculating the Thermoelectric Efficiency
Institute of Scientific and Technical Information of China (English)
吴一东; 王志敏; 何元金
2004-01-01
We present an approximate method for calculating the thermoelectric effciency. The method has a high precision and is applicable to almost all of the thermoelectric devices. The expression for the thermoelectric efficiency we obtained does not involve the position variable, so the calculations are simplified greatly.
Calculation of transonic flows using an extended integral equation method
Nixon, D.
1976-01-01
An extended integral equation method for transonic flows is developed. In the extended integral equation method velocities in the flow field are calculated in addition to values on the aerofoil surface, in contrast with the less accurate 'standard' integral equation method in which only surface velocities are calculated. The results obtained for aerofoils in subcritical flow and in supercritical flow when shock waves are present compare satisfactorily with the results of recent finite difference methods.
Approximate design calculation methods for radiation streaming in shield irregularities
Energy Technology Data Exchange (ETDEWEB)
Miura, Toshimasa; Hirao, Yoshihiro [Ship Research Inst., Mitaka, Tokyo (Japan); Yoritsune, Tsutomu
1997-10-01
Investigation and assessment are made for approximate design calculation methods of radiation streaming in shield irregularities. Investigation is made for (1) source, (2) definition of streaming radiation components, (3) calculation methods of streaming radiation, (4) streaming formulas for each irregularity, (5) difficulties in application of streaming formulas, etc. Furthermore, investigation is made for simple calculation codes and albedo data. As a result, it is clarified that streaming calculation formulas are not enough to cover various irregularities and their accuracy or application limit is not sufficiently clear. Accurate treatment is not made in the formulas with respect to the radiation behavior for slant incidence, bend part, offset etc., that results in too much safety factors in the design calculation and distrust of the streaming calculation. To overcome the state and improve the accuracy of the design calculation for shield irregularities, it is emphasized to assess existing formulas and develop better formulas based on systematic experimental studies. (author)
Iterative acceleration methods for Monte Carlo and deterministic criticality calculations
International Nuclear Information System (INIS)
If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors
Iterative acceleration methods for Monte Carlo and deterministic criticality calculations
Energy Technology Data Exchange (ETDEWEB)
Urbatsch, T.J.
1995-11-01
If you have ever given up on a nuclear criticality calculation and terminated it because it took so long to converge, you might find this thesis of interest. The author develops three methods for improving the fission source convergence in nuclear criticality calculations for physical systems with high dominance ratios for which convergence is slow. The Fission Matrix Acceleration Method and the Fission Diffusion Synthetic Acceleration (FDSA) Method are acceleration methods that speed fission source convergence for both Monte Carlo and deterministic methods. The third method is a hybrid Monte Carlo method that also converges for difficult problems where the unaccelerated Monte Carlo method fails. The author tested the feasibility of all three methods in a test bed consisting of idealized problems. He has successfully accelerated fission source convergence in both deterministic and Monte Carlo criticality calculations. By filtering statistical noise, he has incorporated deterministic attributes into the Monte Carlo calculations in order to speed their source convergence. He has used both the fission matrix and a diffusion approximation to perform unbiased accelerations. The Fission Matrix Acceleration method has been implemented in the production code MCNP and successfully applied to a real problem. When the unaccelerated calculations are unable to converge to the correct solution, they cannot be accelerated in an unbiased fashion. A Hybrid Monte Carlo method weds Monte Carlo and a modified diffusion calculation to overcome these deficiencies. The Hybrid method additionally possesses reduced statistical errors.
Development and Analysis of Train Brake Curve Calculation Methods with Complex Simulation
Directory of Open Access Journals (Sweden)
Bela Vincze
2006-01-01
Full Text Available This paper describes an efficient method using simulation for developing and analyzing train brake curve calculation methods for the on-board computer of the ETCS system. An application example with actual measurements is also presented.
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The improved form of calculation formula for the activities of the components in binary liquids and solid alloys has been derived based on the free volume theory considering excess entropy and Miedema's model for calculating the formation heat of binary alloys. A calculation method of excess thermodynamic functions for binary alloys, the formulas of integral molar excess properties and partial molar excess properties for solid ordered or disordered binary alloys have been developed. The calculated results are in good agreement with the experimental values.
A finite element method for SSI time history calculation
International Nuclear Information System (INIS)
The method which is proposed is based on a finite element modelization for the soil and the structure and a time history calculation. It has been developed for plane and axisymmetric geometries. The principle of this method is presented, then applications are given, first to a linear calculation for which results will be compared to those obtained by standard methods. Then results for a non linear behavior are described
Directory of Open Access Journals (Sweden)
CarloAlberto Redi
2010-09-01
Full Text Available Rightly stressed by prof. Wolfgang Walz in the Preface to the series Neuromethods series, the “careful application of methods is probably the most important step in the process of scientific inquiry”. Thus, I strongly suggest to all those interested in calcium signaling and especially to the new-comers in the hot topic of neuroscience (which has so much space even in science-society debate for its implications in legal issues and in the judge-decision process to take profit from this so well edited book. I am saying this since prof. Verkhratsky and prof. Petersen......
Fluid-structure interaction calculations using a linear perturbation method
International Nuclear Information System (INIS)
Aim of the work is to present and validate FSI (Fluid-Structure Interaction) calculations by using a linear perturbation method and commercial Computational Fluid Dynamics (CFD) and structural analysis codes. Star-CD is used for CFD calculations and ABAQUS for structural analysis. The external MpCCI code is used for coupling the CFD and structural analysis codes
International Nuclear Information System (INIS)
This paper addresses the problem of calculating the bioimpedance phase angle from measurements of impedance modulus. A complete impedance measurement was performed on altogether 20 healthy persons using a Solatron 1260/1294 system. The obtained impedance modulus (absolute impedance value) values were used to calculate the Cole parameters and from them the phase angles. In addition, the phase angles were also calculated using a Kramers–Kronig approach. A correlation analysis for all subjects at each frequency (5, 50, 100 and 200 kHz) for both methods gave R2 values ranging from 0.7 to 0.96 for the Cole approach and from 0.83 to 0.96 for the Kramers–Kronig approach; thus, both methods gave good results compared with the complete measurement results. From further statistical significance testing of the absolute value of the difference between measured and calculated phase angles, it was found that the Cole equation method gave significantly better agreement for the 50 and 100 kHz frequencies. In addition, the Cole equation method gives the four Cole parameters (R0, R∞, τz and α) using measurements at frequencies up to 200 kHz while the Kramers–Kronig method used frequencies up to 500 kHz to reduce the effect of truncation on the calculated results. Both methods gave results that can be used for further bioimpedance calculations, thus improving the application potential of bioimpedance measurement results obtained using relatively inexpensive and portable measurement equipment
Seismic response based on transient calculations. Spectral and stochastic methods
International Nuclear Information System (INIS)
Further to the recent development in the ASTER code of functionalities enabling random dynamic responses to be calculated, notably a stochastic type seismic analysis, we propose a combination of three calculation methods to estimate a probabilistic seismic response on an N4 reactor building stick-model. Transient calculations involves time-and cost-consuming repetition. The conventional oscillator response spectrum calculation yields only the maximum response expectation. On the other hand, the stochastic approach in this context gives the response corresponding to selected probabilities. (authors). 12 figs., 3 tabs., 4 refs
Protein-protein binding affinities calculated using the LIE method
Andberg, Tor Arne Heim
2011-01-01
Absolute binding free energies for the third domain of the turkey ovomucoid inhibitor in complex with Streptomyces griseus proteinase B and porcine pancreatic elastase has been calculated using the linear interaction energy method.
A valid method of calculating virtual scene depth
Institute of Scientific and Technical Information of China (English)
QUAN Hong-yan; ZHANG Tian-wen; LIN Xiang-hong
2005-01-01
A valid method of virtual scene depth calculating is put forward. In this method cameras rotate in three different viewpoints in the plane and we calculate the depth of panorama using three stitching cylinder panoramas. In the investigation, the column of panorama is regarded as a slot image. Using the conic intersected by the epipolar plane and the cylinder, we can obtain the perpendicularity disparity. In order to obtain dense correspondence fast and accurately, a new method of obtaining horizontal disparity using depth continuity is also put forward. It converts the problem of panorama dense correspondence to the problem of searching points in the conic. The occlusion problem is dealt with using three cylinders in the depth calculation. It is verified that this method is convenient, useful and efficient in calculating the depth of a virtual scene.
Theoretical and methodical support of calculating expenses for quality
Пархоменко, Валерій Миколайович
2015-01-01
A hybrid models of calculating expenses for quality on the full life cycle in combination with types of expenses on purpose and model of goods costing considering expenses for quality by standard-functional method have been developed.
CALCULATION OF COMPANY COSTS THROUGH THE DIRECT-COSTING CALCULATION METHOD
Directory of Open Access Journals (Sweden)
Florin-Constantin DIMA
2013-06-01
Full Text Available The cost of production has as its starting point the purchase cost of raw materials and consumables, as well as their processing cost and the calculation of the production cost involves complex aspects. This article is based on the two major concepts of costs calculation, namely the concept of full costs and the concept of partial costs, and it analyses the direct-costing calculation method. Necessity of the Development of calculation methods to ensure rapid determination of the cost of production, and the establishment of indicators broad spectrum of information necessary for making decisions to streamline a business activity conducted by direct-costing method. Direct-costing method appeared in the U.S. for the first time in 1934 (applied by Jonathan Harris and G. Charter Harrison. Subsequently, this method was applied to European countries (England, France, Germany etc.. We stopped on this method because it is considered a modern method of costing. Therefore, we analyzed both advantages and limitations of the method in question
Comparison study on cell calculation method of fast reactor
International Nuclear Information System (INIS)
Effective cross sections obtained by cell calculations are used in core calculations in current deterministic methods. Therefore, it is important to calculate the effective cross sections accurately and several methods have been proposed. In this study, some of the methods are compared to each other using a continuous energy Monte Carlo method as a reference. The result shows that the table look-up method used in Japan Nuclear Cycle Development Institute (JNC) sometimes has a difference over 10% in effective microscopic cross sections and be inferior to the sub-group method. The problem was overcome by introducing a new nuclear constant system developed in JNC, in which the ultra free energy group library is used. The system can also deal with resonance interaction effects between nuclides which are not able to be considered by other methods. In addition, a new method was proposed to calculate effective cross section accurately for power reactor fuel subassembly where the new nuclear constant system cannot be applied. This method uses the sub-group method and the ultra fine energy group collision probability method. The microscopic effective cross sections obtained by this method agree with the reference values within 5% difference. (author)
Methods for tornado frequency calculation of nuclear power plant
International Nuclear Information System (INIS)
In order to take probabilistic safety assessment of nuclear power plant tornado attack event, a method to calculate tornado frequency of nuclear power plant is introduced based on HAD 101/10 and NUREG/CR-4839 references. This method can consider history tornado frequency of the plant area, construction dimension, intensity various along with tornado path and area distribution and so on and calculate the frequency of different scale tornado. (authors)
Measurement, calculation and evaluation of photon production cross-sections
International Nuclear Information System (INIS)
The meeting proceedings were divided into three sessions devoted to the following topics: Experimental measurement and techniques (3 papers), calculation of photon cross-sections (9 papers), and evaluation (2 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs
Institute of Scientific and Technical Information of China (English)
吴拥勋; 江岳文; 温步瀛
2014-01-01
This paper introduces measuring and calculation on each part value caused after grid connected with wind power. Wind power value was divided into positive value which included environmental value and social value and negative value which included changes of load adjustment cost,frequency adjustment cost and spinning reserve cost caused by uncertainty and peak shaving characteristic of wind power.Thereinto,the environmental value included emission benefit,water saving benefit and resource benefit while the social value indicated active impact on human health by environmental value of wind power.At last,by using improved equivalent electricity quantity frequency method (be called for short as strain equivalent electricity quantity frequency method),random production simulation was conducted for the example and each part value was analyzed according to simulation results.%测算了风电并网后引起的各部分价值，将风电的价值分为正面价值和负面价值，正面价值包括环境价值、社会价值，其中环境效益包括减排效益、节水效益、资源效益，社会价值指的是风电的环境效益对人类健康带来的积极影响；负面价值包括因风电的不确定性、反调峰特性而造成调峰成本、调频成本和旋转备用成本变化。最后利用改进后的等效电量频率法(简称应变型等效电量频率法)对算例进行随机生产模拟，根据模拟结果对各部分价值进行分析。
Calculation methods for SPF for heat pump systems for comparison, system choice and dimensioning
Energy Technology Data Exchange (ETDEWEB)
Nordman, Roger; Andersson, Kajsa; Axell, Monica; Lindahl, Markus
2010-09-15
In this project, results from field measurements of heat pumps have been collected and summarised. Also existing calculation methods have been compared and summarised. Analyses have been made on how the field measurements compare to existing calculation models for heat pumps Seasonal Performance Factor (SPF), and what deviations may depend on. Recommendations for new calculation models are proposed, which include combined systems (e.g. solar - HP), capacity controlled heat pumps and combined DHW and heating operation
Simplified hourly method to calculate summer temperatures in dwellings
DEFF Research Database (Denmark)
Mortensen, Lone Hedegaard; Aggerholm, Søren
2012-01-01
with further simplifications. The method is used for calculating room temperatures for all hours of a reference year. It is essential that the simplified method is able to predict the temperature in the room with the highest heat load. The heat load is influenced by the solar load, internal load...... and solar load. The developed method can calculate the number of hours above a given temperature limit. The limits are a prerequisite for the development of the simplified method, and a supplementary maximum temperature limit is suggested to ensure robustness. The setting of the ventilation rate is...
Methods for Measuring Aggregate Costs of Conflict
Gardeazabal, Javier
2010-01-01
This paper reviews the methods for measuring the economic cost of conflict. Estimating the economic costs of conflict requires a counterfactual calculation, which makes this a very difficult task. Social researchers have resorted to different estimation methods depending on the particular effect in question. The method used in each case depends on the units being analyzed (firms, sectors, regions or countries), the outcome variable under study (aggregate output, market valuation of firms, mar...
Calculated and measured emittance of sputter-type negative-ion source
International Nuclear Information System (INIS)
A method for calculating the beam current and emittance of a negative ion beam from a sputter-type source is described. Calculations are compared to measured emittance. The dependence of the emittance on ion source parameters such as cathode shape, exit aperture diameter, and cathode voltage is discussed
Automated methods of corrosion measurement
DEFF Research Database (Denmark)
Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch;
1997-01-01
Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...
Calculation method for gamma-dose rates from spherical puffs
International Nuclear Information System (INIS)
The Lagrangian puff-models are widely used for calculation of the dispersion of atmospheric releases. Basic output from such models are concentrations of material in the air and on the ground. The most simple method for calculation of the gamma dose from the concentration of airborne activity is based on semi-infinite cloud model. This method is however only applicable for points far away from the release point. The exact calculation of the cloud dose using the volume integral requires significant computer time. The volume integral for the gamma dose could be approximated by using the semi-infinite cloud model combined with correction factors. This type of calculation procedure is very fast, but usually the accuracy is poor due to the fact that the same correction factors are used for all isotopes. The authors describe a more elaborate correction method. This method uses precalculated values of the gamma-dose rate as a function of the puff dispersion parameter (δp) and the distance from the puff centre for four energy groups. The release of energy for each radionuclide in each energy group has been calculated and tabulated. Based on these tables and a suitable interpolation procedure the calculation of gamma doses takes very short time and is almost independent of the number of radionuclides. (au) (7 tabs., 7 ills., 12 refs.)
A SIMPLE CALCULATION METHOD FOR DEFINING CREDIT LIMITS OF ENTERPRISES
Directory of Open Access Journals (Sweden)
I TÚRÓCZI
2003-12-01
Full Text Available When setting up and operating a business, one of the most important tasks of the entrepreneur is to secure steady solvency. In order to achieve this and to increase production they often rely on the involvement of external capital. From the point of profitability it is critical to evaluate how these elements of capital will influence expenses and profits. Some of these sources bear no costs making a favourable effect. However, there are other capital sources, which result in a significant increase of expenses. Capital gearing (leverage also brings costs and expenses, which a business must be able to measure and evaluate. We must know the reasonable options to choose and the limits of expensive capital involvement. As part of my consultany work, I have researched this issue and, relying on business literature, I have designed a calculation method which helps to define this limit. In this paper the reader is presented with this method and is encouraged to comment on its effectiveness.
New methods for neutron response calculations with MCNP
Energy Technology Data Exchange (ETDEWEB)
Hendricks, J.S. [Los Alamos National Lab., NM (United States). Applied Theoretical and Computational Physics Div.
1997-05-01
MCNP4B was released for international distribution in February, 1997. The author summarized the new MCNP4B features since the release of MCNP4A over three years earlier and compare some results. Then he describes new methods being developed for future code releases. The focus is methods and applications of ex-core neutron response calculations.
Experimental verification of a recursive method to calculate evapotranspiration
Recently, a recursive combination method (RCM) to calculate potential and crop evapotranspiration (ET) was given by Lascano and Van Bavel (Agron. J. 2007, 99:585–590). The RCM differs from the Penman-Monteith (PM) method, the main difference being that the assumptions made regarding the temperature ...
A simple method for calculating Clebsch-Gordan coefficients
Energy Technology Data Exchange (ETDEWEB)
Klink, W H; Wickramasekara, S, E-mail: william-klink@uiowa.ed, E-mail: wickrama@grinnell.ed, E-mail: s-wickram@uiowa.ed [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States)
2010-09-15
This paper presents a simple method for calculating Clebsch-Gordan coefficients for the tensor product of two unitary irreducible representations (UIRs) of the rotation group. The method also works for multiplicity-free irreducible representations appearing in the tensor product of any number of UIRs of the rotation group. The generalization to representations with multiplicity is straightforward and briefly discussed.
New methods for neutron response calculations with MCNP
International Nuclear Information System (INIS)
MCNP4B was released for international distribution in February, 1997. The author summarized the new MCNP4B features since the release of MCNP4A over three years earlier and compare some results. Then he describes new methods being developed for future code releases. The focus is methods and applications of ex-core neutron response calculations
Efficient Calculation of Near Fields in the FDTD Method
DEFF Research Database (Denmark)
Franek, Ondrej
2011-01-01
When calculating frequency-domain near fields by the FDTD method, almost 50 % reduction in memory and CPU operations can be achieved if only E-fields are stored during the main time-stepping loop and H-fields computed later. An improved method of obtaining the H-fields from Faraday's Law is...
Calculating High Speed Centrifugal Compressor Performance from Averaged Measurements
Lou, Fangyuan; Fleming, Ryan; Key, Nicole L.
2012-12-01
To improve the understanding of high performance centrifugal compressors found in modern aircraft engines, the aerodynamics through these machines must be experimentally studied. To accurately capture the complex flow phenomena through these devices, research facilities that can accurately simulate these flows are necessary. One such facility has been recently developed, and it is used in this paper to explore the effects of averaging total pressure and total temperature measurements to calculate compressor performance. Different averaging techniques (including area averaging, mass averaging, and work averaging) have been applied to the data. Results show that there is a negligible difference in both the calculated total pressure ratio and efficiency for the different techniques employed. However, the uncertainty in the performance parameters calculated with the different averaging techniques is significantly different, with area averaging providing the least uncertainty.
Calculation and comparative measurement of a manipulator boom
International Nuclear Information System (INIS)
A manipulator system is fabricated for the use in a fusion reactor. The system allows to take in any arbitrary position in a plane. It consists of seven linked arms. During resting position, the manipulator boom is folded together in an antechamber. For the working position, the individual links are moved out through the opening to operate in a ring-shaped vacuum vessel. The stress analysis of the boom follows three steps: calculation of the global forces with a beam model dependent on the different working positions of the boom; calculation of the local stresses in the jointed arms with Finite-Element-Models for the worst load combination; and comparison of the calculations with strain gauge measurements
THE INTEGRAL FORMULA FOR CALCULATING THE HAUSDORFF MEASURE OF SOME FRACTAL SETS
Institute of Scientific and Technical Information of China (English)
Lu Shipan; Su Weiyi
2001-01-01
It is important to calculate the Hausdor ff dimen sion and the Hausdor ff mesare res pect to this dimension for some f ractal sets. By using the usual method of “Mass Distribution”, we can only calculate the Hausdor f f dimesion. In this paper , we will construct an integral farmla by using lower inverse s-density and then use it to calculate the Hausdor f f measures for some fractional dimensional sets.
On-line reactivity calculation using Lagrange method
International Nuclear Information System (INIS)
Highlights: • Lagrange method is proposed for on-line reactivity calculation in nuclear reactors. • The need for nuclear power history or the Laplace transform is vanished. • The three- and five-point formulas are presented and examined in different benchmark cases. • Computational time-steps of up to 1 s lead to highly reliable reactivity calculations. • The main advantage of the proposed approach is its stability and convergence in large time-step calculations. - Abstract: In this paper, a novel multi-step method is proposed for solving the inverse point kinetics problem using Lagrange polynomial method. By use of this approach, the need for nuclear power history or the Laplace transform is vanished. Furthermore, the accuracy of the method is of order hn for the (n + 1)-point formula, where h is the computational time-step. The three- and five-point formulas of the Lagrange method are used for on-line reactivity calculations and results are benchmarked against reference solutions for different nuclear power forms. Moreover, results for different computational time-steps are compared in each case. The results show the accuracy of the proposed method in all benchmarking cases. For slow transients (large reactor periods), it is shown that time-steps of up to 1 s lead to highly reliable reactivity calculations. However, the optimal time-step in almost all cases is shown to be 0.1 s. The main advantage of the proposed approach, in contrast with previous numerical methods, is its stability and convergence in large time-step calculations. The proposed method can be used as real time reactivity meter in all nuclear reactors without limitation of nuclear power form
Calculation of Solar Radiation by Using Regression Methods
Kızıltan, Ö.; Şahin, M.
2016-04-01
In this study, solar radiation was estimated at 53 location over Turkey with varying climatic conditions using the Linear, Ridge, Lasso, Smoother, Partial least, KNN and Gaussian process regression methods. The data of 2002 and 2003 years were used to obtain regression coefficients of relevant methods. The coefficients were obtained based on the input parameters. Input parameters were month, altitude, latitude, longitude and landsurface temperature (LST).The values for LST were obtained from the data of the National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer (NOAA-AVHRR) satellite. Solar radiation was calculated using obtained coefficients in regression methods for 2004 year. The results were compared statistically. The most successful method was Gaussian process regression method. The most unsuccessful method was lasso regression method. While means bias error (MBE) value of Gaussian process regression method was 0,274 MJ/m2, root mean square error (RMSE) value of method was calculated as 2,260 MJ/m2. The correlation coefficient of related method was calculated as 0,941. Statistical results are consistent with the literature. Used the Gaussian process regression method is recommended for other studies.
Calculating Method of Moments Uniform Bin Width Histograms
James S. Weber
2016-01-01
A clear articulation of Method of Moments (MOM) Histograms is instructive and has waited 121 years since 1895. Also of interest are enabling uniform bin width (UBW) shape level sets. Mean-variance MOM uniform bin width frequency and density histograms are not unique, however ranking them by histogram skewness compared to data skewness helps. Although theoretical issues rarely take second place to calculations, here calculations based on shape level sets are central and challenge uncritically ...
Refinement of thermal imager minimum resolvable temperature difference calculating method
Kolobrodov, V. G.; Mykytenko, V. I.
2015-11-01
Calculating methods, which accurately predict minimum resolvable temperature difference (MRTD), are of significant interest for many years. The article deals with improvement the accuracy of determining the thermal imaging system MRTD by elaboration the visual perception model. We suggest MRTD calculating algorithm, which is based on a reliable approximation of the human visual system modulation transfer function (MTF) proposed by N. Nill. There was obtained a new expression for the bandwidth evaluation, which is independent of angular size of the Foucault bar target.
The analytic method for calculating the control rod worth
International Nuclear Information System (INIS)
We calculated the control rod worth in this paper. To avoid complexity, we did not consider burnable poisons and soluble boron. The system was localized within one assembly. The control rod was treated as not an absorber but an another boundary. Thus all of the group constants were unchanged before and after control rod insertion. And we discussed the method for calculation of the reactivity of the whole core
A Method for Calculating Collision Probability Between Space Objects
Xu, Xiaoli; Xiong, Yongqing
2013-01-01
A method is developed to calculate collision probability in this paper. Based on the encounter geometric features of space objects, it is reasonable to separate the radial orbital motions from that in the cross section for most encounter events in near circular orbit. Therefore, the collision probability caused by orbit altitude difference in the radial direction and the collision probability caused by arrival time difference in the cross section are calculated respectively. The net collision...
Shape integral method for magnetospheric shapes. [boundary layer calculations
Michel, F. C.
1979-01-01
A method is developed for calculating the shape of any magnetopause to arbitrarily high precision. The method uses an integral equation which is evaluated for a trial shape. The resulting values of the integral equation as a function of auxiliary variables indicate how close one is to the desired solution. A variational method can then be used to improve the trial shape. Some potential applications are briefly mentioned.
Comparison of measured and calculated peripheral doses in patients undergoing radiation therapy
International Nuclear Information System (INIS)
Background and purpose: Many papers have been published on the measurement for specific treatment machines and/or techniques of the dose to points outside the primary beam, often called the peripheral dose (PD). Most papers concern measurements in phantoms. We report on the results of a comparison of estimates of the PD, based on these phantom measurements, with PDs measured on patients. Material and methods: A special holder with thermoluminescent dosimeters was placed against the perineum of patients referred to our institute for radiation therapy. The measured dose was then compared with the dose calculated on the basis of published PD data. Results: For all measurements together, the calculated values exceeded the measured PDs by about 9%, with a standard deviation of 35%. The correlation varied between specific subgroups but the difference between measurement and calculation did not exceed 50%. Conclusions: We conclude that published PD data can be used to accurately predict the peripheral dose in the clinical situation
Solar opacity calculations using the super-transition-array method
Krief, M; Gazit, D
2016-01-01
An opacity model based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of local thermodynamic equilibrium plasmas was developed. The model is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried throughout the solar radiative zone. The relative contributions of different chemical elements and photon-matter processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge state distributions were compared with the widely used Opacity-Project (OP) code, for several elements near the radiation-convection interface. STA Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code, throughout the radiation zone. Finally, an explicit STA calculation of the full AGSS09 photospheric mixture, including all heavy metals was performed. It was shown that due to their extremely low abundance, and despite being very go...
Composite electron propagator methods for calculating ionization energies
Díaz-Tinoco, Manuel; Dolgounitcheva, O.; Zakrzewski, V. G.; Ortiz, J. V.
2016-06-01
Accurate ionization energies of molecules may be determined efficiently with composite electron-propagator (CEP) techniques. These methods estimate the results of a calculation with an advanced correlation method and a large basis set by performing a series of more tractable calculations in which large basis sets are used with simpler approximations and small basis sets are paired with more demanding correlation techniques. The performance of several CEP methods, in which diagonal, second-order electron propagator results with large basis sets are combined with higher-order results obtained with smaller basis sets, has been tested for the ionization energies of closed-shell molecules from the G2 set. Useful compromises of accuracy and computational efficiency employ complete-basis-set extrapolation for second-order results and small basis sets in third-order, partial third-order, renormalized partial-third order, or outer valence Green's function calculations. Analysis of results for vertical as well as adiabatic ionization energies leads to specific recommendations on the best use of regular and composite methods. Results for 22 organic molecules of interest in the design of photovoltaic devices, benzo[a]pyrene, Mg-octaethylporphyrin, and C60 illustrate the capabilities of CEP methods for calculations on large molecules.
Composite electron propagator methods for calculating ionization energies.
Díaz-Tinoco, Manuel; Dolgounitcheva, O; Zakrzewski, V G; Ortiz, J V
2016-06-14
Accurate ionization energies of molecules may be determined efficiently with composite electron-propagator (CEP) techniques. These methods estimate the results of a calculation with an advanced correlation method and a large basis set by performing a series of more tractable calculations in which large basis sets are used with simpler approximations and small basis sets are paired with more demanding correlation techniques. The performance of several CEP methods, in which diagonal, second-order electron propagator results with large basis sets are combined with higher-order results obtained with smaller basis sets, has been tested for the ionization energies of closed-shell molecules from the G2 set. Useful compromises of accuracy and computational efficiency employ complete-basis-set extrapolation for second-order results and small basis sets in third-order, partial third-order, renormalized partial-third order, or outer valence Green's function calculations. Analysis of results for vertical as well as adiabatic ionization energies leads to specific recommendations on the best use of regular and composite methods. Results for 22 organic molecules of interest in the design of photovoltaic devices, benzo[a]pyrene, Mg-octaethylporphyrin, and C60 illustrate the capabilities of CEP methods for calculations on large molecules. PMID:27305999
A method to calculate displacement factors using SVM
Institute of Scientific and Technical Information of China (English)
Li Peixian; Tan Zhixiang; Yan Lili; Deng Kazhong
2011-01-01
In order to improve the precision of mining subsidence prediction,a mathematical model using Support Vector Machine (SVM) was established to calculate the displacement factor.The study is based on a comprehensive analysis of factors affecting the displacement factor,such as mechanical properties of the cover rock,the ratio of mining depth to seam thickness,dip angle of the coal seam and the thickness of loose layer.Data of 63 typical observation stations were used as a training and testing sample set.A SVM regression model of the displacement factor and the factors affecting it was established with a kernel function,an insensitive loss factor and a properly selected penalty factor.Given an accurate calculation algorithm for testing and analysis,the results show that an SVM regression model can calculate displacement factor precisely and reliable precision can be obtained which meets engineering requirements.The experimental results show that the method to calculation of the displacement factor,based on the SVM method,is feasible.The many factors affecting the displacement factor can be considered with this method.The research provides an efficient and accurate approach for the calculation of displacement in mining subsidence prediction.
Penning de Vries, M. J. M.; Tuinder, O. N. E.; Wagner, T.; Fromm, M.
2012-04-01
The Wallow wildfire of 2011 was one of the most devastating fires ever in Arizona, burning over 2,000 km2 in the states of Arizona and New Mexico. The fire originated in the Bear Wallow Wilderness area in June, 2011, and raged for more than a month. The intense heat of the fire caused the formation of a pyro-convective cloud. The resulting smoke plume, partially located above low-lying clouds, was detected by several satellite instruments, including GOME-2 on June 2. The UV Aerosol Index, indicative of aerosol absorption, reached a maximum of 12 on that day, pointing to an elevated plume with moderately absorbing aerosols. We have performed extensive model calculations assuming different aerosol optical properties to determine the total aerosol optical depth of the plume. The plume altitude, needed to constrain the aerosol optical depth, was obtained from independent satellite measurements. The model results were compared with UV Aerosol Index and UV reflectances measured by the GOME-2 polarization measurement devices, which have a spatial resolution of roughly 10x40 km2. Although neither the exact aerosol optical properties nor optical depth can be obtained with this method, the range in aerosol optical depth values that we calculate, combined with the assumed specific extinction mass factor of 5 m2/kg lead us to a rough estimate of the smoke plume mass that cannot, at present, be assessed in another way.
Radiation Environment Variations at Mars - Model Calculations and Measurements
Saganti, Premkumar; Cucinotta, Francis
Variations in the space radiation environment due to changes in the GCR (Galactic Cosmic Ray) from the past (#23) solar cycle to the current one (#24) has been intriguing in many ways, with an unprecedented long duration of the recent solar minimum condition and a very low peak activity of the current solar maximum. Model calculated radiation data and assessment of variations in the particle flux - protons, alpha particles, and heavy ions of the GCR environment is essential for understanding radiation risk and for any future intended long-duration human exploration missions. During the past solar cycle, we have had most active and higher solar maximum (2001-2003) condition. In the beginning of the current solar cycle (#24), we experienced a very long duration of solar minimum (2009-2011) condition with a lower peak activity (2013-2014). At Mars, radiation measurements in orbit were obtained (onboard the 2001 Mars Odyssey spacecraft) during the past (#23) solar maximum condition. Radiation measurements on the surface of Mars are being currently measured (onboard the Mars Science Laboratory, 2012 - Curiosity) during the current (#24) solar peak activity (August 2012 - present). We present our model calculated radiation environment at Mars during solar maxima for solar cycles #23 and #24. We compare our earlier model calculations (Cucinotta et al., J. Radiat. Res., 43, S35-S39, 2002; Saganti et al., J. Radiat. Res., 43, S119-S124, 2002; and Saganti et al., Space Science Reviews, 110, 143-156, 2004) with the most recent radiation measurements on the surface of Mars (2012 - present).
A Method for Calculating Collision Probability Between Space Objects
Xu, Xiaoli
2013-01-01
A method is developed to calculate collision probability in this paper. Based on the encounter geometric features of space objects, it is reasonable to separate the radial orbital motions from that in the cross section for most encounter events in near circular orbit. Therefore, the collision probability caused by orbit altitude difference in the radial direction and the collision probability caused by arrival time difference in the cross section are calculated respectively. The net collision probability is expressed as an explicit expression by multiplying the above two components. Numerical cases are applied to test this method by comparing the results with the general method. The results indicate that this method is valid for most near circular orbital encounter events.
Emergy Algebra: Improving Matrix Methods for Calculating Tranformities
Transformity is one of the core concepts in Energy Systems Theory and it is fundamental to the calculation of emergy. Accurate evaluation of transformities and other emergy per unit values is essential for the broad acceptance, application and further development of emergy method...
Investigation of methods used in calculations of solar cell parameters
Shvets, E. Ya.; Khrypko, S. L.; Zubko, E. I.
2009-01-01
Analytical expressions have been obtained for extracting the electrical parameters and characteristics of solar cells, including series and shunt resistances, and the saturation current. The method of Lagrange multipliers was used for computing the shape factor of the current–voltage characteristic (CVC) of solar cell. The calculation results demonstrated a satisfactory agreement with experimental data.
Calculation of statistical entropic measures in a model of solids
International Nuclear Information System (INIS)
In this work, a one-dimensional model of crystalline solids based on the Dirac comb limit of the Krönig–Penney model is considered. From the wave functions of the valence electrons, we calculate a statistical measure of complexity and the Fisher–Shannon information for the lower energy electronic bands appearing in the system. All these magnitudes present an extremal value for the case of solids having half-filled bands, a configuration where in general a high conductivity is attained in real solids, such as it happens with the monovalent metals. -- Highlights: ► A simplified model of solids is considered. Its electronic band structure is calculated. ► The statistical complexity and the Fisher–Shannon information are computed on this model. ► The extremal value for this indicators are taken on the configurations showing the highest conductivity.
Calculation of statistical entropic measures in a model of solids
Energy Technology Data Exchange (ETDEWEB)
Sañudo, Jaime, E-mail: jsr@unex.es [Departamento de Física, Facultad de Ciencias, Universidad de Extremadura, E-06071 Badajoz (Spain); BIFI, Universidad de Zaragoza, E-50009 Zaragoza (Spain); López-Ruiz, Ricardo, E-mail: rilopez@unizar.es [DIIS and BIFI, Facultad de Ciencias, Universidad de Zaragoza, E-50009 Zaragoza (Spain)
2012-07-09
In this work, a one-dimensional model of crystalline solids based on the Dirac comb limit of the Krönig–Penney model is considered. From the wave functions of the valence electrons, we calculate a statistical measure of complexity and the Fisher–Shannon information for the lower energy electronic bands appearing in the system. All these magnitudes present an extremal value for the case of solids having half-filled bands, a configuration where in general a high conductivity is attained in real solids, such as it happens with the monovalent metals. -- Highlights: ► A simplified model of solids is considered. Its electronic band structure is calculated. ► The statistical complexity and the Fisher–Shannon information are computed on this model. ► The extremal value for this indicators are taken on the configurations showing the highest conductivity.
Optimization method for quantitative calculation of clay minerals in soil
Indian Academy of Sciences (India)
Libo Hao; Qiaoqiao Wei; Yuyan Zhao; Zilong Lu; Xinyun Zhao
2015-04-01
Determination of types and amounts for clay minerals in soil are important in environmental, agricultural, and geological investigations. Many reliable methods have been established to identify clay mineral types. However, no reliable method for quantitative analysis of clay minerals has been established so far. In this study, an attempt was made to propose an optimization method for the quantitative determination of clay minerals in soil based on bulk chemical composition data. The fundamental principles and processes of the calculation are elucidated. Some samples were used for reliability verification of the method and the results prove the simplicity and efficacy of the approach.
STABILIZER BARS – CALCULATIONS, CONSTRUCTION AND PRODUCTION METHODS
Directory of Open Access Journals (Sweden)
Adam Marek WITTEK
2015-06-01
Full Text Available The article outlines the calculation and production methods for stabilizer bars. Modern technological and structural solutions in contemporary cars are reflected also in the construction and manufacturing of stabilizer bars. A proper construction and the selection of parameters influence the strength properties, the weight, durability and reliability as well as the selection of an appropriate production method. The selection of the manufacturing process has a fundamental impact on the quality and durability of the stabilizer bars.
Calculating resonance positions and widths using the Siegert approximation method
Rapedius, Kevin
2011-01-01
Here we present complex resonance states (or Siegert states), that describe the tunneling decay of a trapped quantum particle, from an intuitive point of view which naturally leads to the easily applicable Siegert approximation method that can be used for analytical and numerical calculations of complex resonances of both the linear and nonlinear Schr\\"odinger equation. Our approach thus complements other treatments of the subject that mostly focus on methods based on continuation in the complex plane or on semiclassical approximations.
Unstable optical resonator loss calculations using the prony method.
Siegman, A E; Miller, H Y
1970-12-01
The eigenvalues for all the significant low-order resonant modes of an unstable optical resonator with circular mirrors are computed using an eigenvalue method called the Prony method. A general equivalence relation is also given, by means of which one can obtain the design parameters for a single-ended unstable resonator of the type usually employed in practical lasers, from the calculated or tabulated values for an equivalent symmetric or double-ended unstable resonator.
Theories and calculation methods for regional objective ET (evapotranspiration): Applications
Institute of Scientific and Technical Information of China (English)
LIU diaHong; QIN DaYong; WANG MingNa; L(U) JinYan; SANG XueFeng; ZHANG RuiMei
2009-01-01
The regional objective ET (evapotranspiration) is defined as the quantity of water that could be con-sumed in a particular region. It varies with the water conditions and economic development stages in the region. It is also constrained by the requirement of benign environment cycle. At the same time, it must meet the demands of sustainable economic growth and the construction of harmony society.Objective ET based water resources distribution will replace the conventional method, which empha-sizes the balance between the water demand and the water supply. It puts focus on the reasonable water consumption instead of the forecasted water demand, which is usually greater than the actual one. In this paper, we calculated the objective ET of 2010 year level in Tianjin by an analysis-integra-tion-assessment method. Objective ET can be classified into two parts: controllable ET and uncontrol-lable ET. Controllable ET includes the ET from irrigation land and the ET from resident land, among which the former can be calculated with soil moisture model and evapotranspiration model, while the latter can be calculated by water use ration and water consumption rate. The uncontrollable ET can be calculated with the distributed hydrological model and the remote sensing monitoring model. The two models can be mutually calibrated. In this paper, eight schemes are put forward based on different portfolios of water resources. The objective ET of each scheme was calculated and the results were assessed and analyzed. Finally, an optimal scheme was recommended.
Calculation of free-fall trajectories using numerical optimization methods.
Hull, D. G.; Fowler, W. T.; Gottlieb, R. G.
1972-01-01
An important problem in space flight is the calculation of trajectories for nonthrusting vehicles between fixed points in a given time. A new procedure based on Hamilton's principle for solving such two-point boundary-value problems is presented. It employs numerical optimization methods to perform the extremization required by Hamilton's principle. This procedure is applied to the calculation of an Earth-Moon trajectory. The results show that the initial guesses required to obtain an iteration procedure which converges are not critical and that convergence can be obtained to any predetermined degree of accuracy.
A new method for the automatic calculation of prosody
International Nuclear Information System (INIS)
An algorithm is presented for the calculation of the prosodic parameters for speech synthesis. It uses the melodic patterns, composed of rising and falling slopes, suggested by G. CAELEN, and rests on: 1. An analysis into units of meaning to determine a melodic pattern 2. the calculation of the numeric values for the prosodic variations of each syllable; 3. The use of a table of vocalic values for the three parameters for each vowel according to the consonantal environment and of a table of standard duration for consonants. This method was applied in the 'SARA' program of synthesis with satisfactory results. (author)
Slab Storage Calculation Method for Continuous Casting-Hot Rolling
Institute of Scientific and Technical Information of China (English)
PENG Qi-chun; LIU Qing; TIAN Nai-yuan
2004-01-01
Based on load-oriented manufacturing control theory, different combining modes and slab storage calculation method for continuous casting and hot rolling were discussed. The buffer capacity index of continuous casting-rolling was introduced, and the reasonable slab storage under different combining modes was calculated with buffer capacity index of 120.00 h for CCR, 79.20 h for HCR, 19.68 h for DHCR and 3.84 h for DR. Thin slab is 1.20 h, and the strip is zero. Theory gist was provided for steel enterprise to decrease storage.
Calculation of statistical entropic measures in a model of solids
Sanudo, Jaime
2012-01-01
In this work, a one-dimensional model of crystalline solids based on the Dirac comb limit of the Kronig-Penney model is considered. From the wave functions of the valence electrons, we calculate a statistical measure of complexity and the Fisher-Shannon information for the lower energy electronic bands appearing in the system. All these magnitudes present an extremal value for the case of solids having half-filled bands, a configuration where in general a high conductivity is attained in real solids, such as it happens with the monovalent metals.
Field calculation of D0 toroids and comparison with measurement
Energy Technology Data Exchange (ETDEWEB)
Yamada, R.; Ostiguy, F.; Brzezniak, J.
1992-06-01
The magnetic structure of the D0 detector is described in an earlier report. The two-dimensional code POISSON was used for the initial design of the magnetic structures and the magnetic properties of the D0 toroids. During the construction, the two-dimensional code ANSYS was used to perform more detailed calculations. Full three-dimensional analysis was also performed using the code TOSCA. These new results are reported here and compared with measurements. In this study the magnetic flux in all toroids, CF, EF, and SAMUS is set in the same direction.
Load calculation methods for offshore wind turbine foundations
DEFF Research Database (Denmark)
Passon, Patrik; Branner, Kim
2014-01-01
Calculation of design loads for offshore wind turbine (OWT) foundations is typically performed in a joint effort between wind turbine manufactures and foundation designers (FDs). Ideally, both parties would apply the same fully integrated design tool and model for that purpose. However, such solu......Calculation of design loads for offshore wind turbine (OWT) foundations is typically performed in a joint effort between wind turbine manufactures and foundation designers (FDs). Ideally, both parties would apply the same fully integrated design tool and model for that purpose. However...... turbine manufacturer provides the FD with dynamic responses obtained from aeroelastic simulations at a predefined interface. These responses are subsequently expanded to the corresponding dynamic responses in all structural parts of the foundation. In this article, a novel load calculation method......, for the expansion to dynamic foundation responses based on an inverse dynamics algorithm, is introduced and described in detail. Furthermore, a summary of load calculation methods currently applied for the design of bottom-mounted OWTs foundations is provided and compared with the proposed method. While emphasis...
Comparison of analytical methods for calculation of wind loads
Minderman, Donald J.; Schultz, Larry L.
1989-01-01
The following analysis is a comparison of analytical methods for calculation of wind load pressures. The analytical methods specified in ASCE Paper No. 3269, ANSI A58.1-1982, the Standard Building Code, and the Uniform Building Code were analyzed using various hurricane speeds to determine the differences in the calculated results. The winds used for the analysis ranged from 100 mph to 125 mph and applied inland from the shoreline of a large open body of water (i.e., an enormous lake or the ocean) a distance of 1500 feet or ten times the height of the building or structure considered. For a building or structure less than or equal to 250 feet in height acted upon by a wind greater than or equal to 115 mph, it was determined that the method specified in ANSI A58.1-1982 calculates a larger wind load pressure than the other methods. For a building or structure between 250 feet and 500 feet tall acted upon by a wind rangind from 100 mph to 110 mph, there is no clear choice of which method to use; for these cases, factors that must be considered are the steady-state or peak wind velocity, the geographic location, the distance from a large open body of water, and the expected design life and its risk factor.
Accelerating molecular property calculations with nonorthonormal Krylov space methods
Furche, Filipp; Krull, Brandon T.; Nguyen, Brian D.; Kwon, Jake
2016-05-01
We formulate Krylov space methods for large eigenvalue problems and linear equation systems that take advantage of decreasing residual norms to reduce the cost of matrix-vector multiplication. The residuals are used as subspace basis without prior orthonormalization, which leads to generalized eigenvalue problems or linear equation systems on the Krylov space. These nonorthonormal Krylov space (nKs) algorithms are favorable for large matrices with irregular sparsity patterns whose elements are computed on the fly, because fewer operations are necessary as the residual norm decreases as compared to the conventional method, while errors in the desired eigenpairs and solution vectors remain small. We consider real symmetric and symplectic eigenvalue problems as well as linear equation systems and Sylvester equations as they appear in configuration interaction and response theory. The nKs method can be implemented in existing electronic structure codes with minor modifications and yields speed-ups of 1.2-1.8 in typical time-dependent Hartree-Fock and density functional applications without accuracy loss. The algorithm can compute entire linear subspaces simultaneously which benefits electronic spectra and force constant calculations requiring many eigenpairs or solution vectors. The nKs approach is related to difference density methods in electronic ground state calculations and particularly efficient for integral direct computations of exchange-type contractions. By combination with resolution-of-the-identity methods for Coulomb contractions, three- to fivefold speed-ups of hybrid time-dependent density functional excited state and response calculations are achieved.
Calculation of interface curvature with the level-set method
Lervåg, Karl Yngve
2014-01-01
The level-set method is a popular method for interface capturing. One of the advantages of the level-set method is that the curvature and the normal vector of the interface can be readily calculated from the level-set function. However, in cases where the level-set method is used to capture topological changes, the standard discretization techniques for the curvature and the normal vector do not work properly. This is because they are affected by the discontinuities of the signed-distance function half-way between two interfaces. This article addresses the calculation of normal vectors and curvatures with the level-set method for such cases. It presents a discretization scheme that is relatively easy to implement in to an existing code. The improved discretization scheme is compared with a standard discretization scheme, first for a case with no flow, then for a case where two drops collide in a shear flow. The results show that the improved discretization yields more robust calculations in areas where topolo...
International Nuclear Information System (INIS)
A new code was developed that calculates the spectrum, the state and the degree of polarization of the radiation emitted by any insertion device. It integrates along an arbitrary electron trajectory without any approximations. The trajectory can be derived either from a model undulator including random field errors or from a measured field distribution from a real undulator. The calculated one-electron pattern is convoluted with the electron beam emittance. Spectral calculations for the crossed field undulator U-2 at BESSY employing measured magnetic field data agree with absolute measurements of the spectra. (author) 18 refs.; 1 fig
Artificial Boundary Method for Calculating Ship Wave Resistance
Institute of Scientific and Technical Information of China (English)
文新; 韩厚德
2003-01-01
The calculation of wave resistance for a ship moving at constant speed near a free surface is considered. This wave resistance is calculated with a linearized steady potential model. To deal with the unboundedness of the physical domain in the potential flow problem, we introduce one vertical side as an artificial upstream boundary and two vertical sides as the artificial downstream boundaries. On the artificial boundaries, a sequence of high-order global artificial boundary conditions are given. Then the potential flow problem is reduced to a problem defined on a finite computational domain, which is equivalent to a variational problem. The solution of the variational problem by the finite element method gives the numerical approximation of the potential flow around the ship, which was used to calculate the wave resistance. The numerical examples show the accuracy and efficiency of the proposed numerical scheme.
Energy Technology Data Exchange (ETDEWEB)
Meireles, Ramiro Conceicao
2016-07-01
The shielding calculation methodology for radiotherapy services adopted in Brazil and in several countries is that described in publication 151 of the National Council on Radiation Protection and Measurements (NCRP 151). This methodology however, markedly employs several approaches that can impact both in the construction cost and in the radiological safety of the facility. Although this methodology is currently well established by the high level of use, some parameters employed in the calculation methodology did not undergo to a detailed assessment to evaluate the impact of the various approaches considered. In this work the MCNP5 Monte Carlo code was used with the purpose of evaluating the above mentioned approaches. TVLs values were obtained for photons in conventional concrete (2.35g / cm{sup 3}), considering the energies of 6, 10 and 25 MeV, respectively, first considering an isotropic radiation source impinging perpendicular to the barriers, and subsequently a lead head shielding emitting a shaped beam, in the format of a pyramid trunk. Primary barriers safety margins, taking in account the head shielding emitting photon beam pyramid-shaped in the energies of 6, 10, 15 and 18 MeV were assessed. A study was conducted considering the attenuation provided by the patient's body in the energies of 6,10, 15 and 18 MeV, leading to new attenuation factors. Experimental measurements were performed in a real radiotherapy room, in order to map the leakage radiation emitted by the accelerator head shielding and the results obtained were employed in the Monte Carlo simulation, as well as to validate the entire study. The study results indicate that the TVLs values provided by (NCRP, 2005) show discrepancies in comparison with the values obtained by simulation and that there may be some barriers that are calculated with insufficient thickness. Furthermore, the simulation results show that the additional safety margins considered when calculating the width of the
Calculation of Turbulent Boundary Layers Using the Dissipation Integral Method
Institute of Scientific and Technical Information of China (English)
MatthiasBuschmann
1999-01-01
This paper gives an introduction into the dissipation integral method.The general integral equations for the three-dimensional case are derved.It is found that for a practical calculation algorithm the integral monentum equation and the integral energy equation are msot useful.Using Two different sets of mean velocity profiles the hyperbolical character of a dissipation integral method is shown.Test cases for two-and three-dimensional boundary layers are analysed and discussed.The paper concludes with a discussion of the advantages and limits of dissipation integral methods.
Comparison between calculation methods of dose rates in gynecologic brachytherapy
International Nuclear Information System (INIS)
In treatments with radiations for gynecologic tumors is necessary to evaluate the quality of the results obtained by different calculation methods for the dose rates on the points of clinical interest (A, rectal, vesicle). The present work compares the results obtained by two methods. The Manual Calibration Method (MCM) tri dimensional (Vianello E., et.al. 1998), using orthogonal radiographs for each patient in treatment, and the Theraplan/T P-11 planning system (Thratonics International Limited 1990) this last one verified experimentally (Vianello et.al. 1996). The results show that MCM can be used in the physical-clinical practice with a percentile difference comparable at the computerized programs. (Author)
Experiences with leak rate calculations methods for LBB application
Energy Technology Data Exchange (ETDEWEB)
Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G. [and others
1997-04-01
In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations.
Laub, Wolfram U.; Bakai, Annemarie; Nüsslin, Fridtjof
2001-06-01
The present study investigates the application of compensators for the intensity modulated irradiation of a thorax phantom. Measurements are compared with Monte Carlo and standard pencil beam algorithm dose calculations. Compensators were manufactured to produce the intensity profiles that were generated from the scientific version of the KonRad IMRT treatment-planning system for a given treatment plan. The comparison of dose distributions calculated with a pencil beam algorithm, with the Monte Carlo code EGS4 and with measurements is presented. By measurements in a water phantom it is demonstrated that the method used to manufacture the compensators reproduces the intensity profiles in a suitable manner. Monte Carlo simulations in a water phantom show that the accelerator head model used for simulations is sufficient. No significant overestimations of dose values inside the target volume by the pencil beam algorithm are found in the thorax phantom. An overestimation of dose values in lung by the pencil beam algorithm is also not found. Expected dose calculation errors of the pencil beam algorithm are suppressed, because the dose to the low density region lung is reduced by the use of a non-coplanar beam arrangement and by intensity modulation.
Using A Particular Sampling Method for Impedance Measurement
Lentka Grzegorz
2014-01-01
The paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was then practically verified in a constructed simple impedance measu...
Sørensen, R.; Zinko, U.; Seibert, J.
2005-01-01
The topographic wetness index (TWI, ln(a/tanβ)), which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwa...
Methods and computer codes for nuclear systems calculations
Indian Academy of Sciences (India)
B P Kochurov; A P Knyazev; A Yu Kwaretzkheli
2007-02-01
Some numerical methods for reactor cell, sub-critical systems and 3D models of nuclear reactors are presented. The methods are developed for steady states and space–time calculations. Computer code TRIFON solves space-energy problem in (, ) systems of finite height and calculates heterogeneous few-group matrix parameters of reactor cells. These parameters are used as input data in the computer code SHERHAN solving the 3D heterogeneous reactor equation for steady states and 3D space–time neutron processes simulation. Modification of TRIFON was developed for the simulation of space–time processes in sub-critical systems with external sources. An option of SHERHAN code for the system with external sources is under development.
Implicit calculations of transonic flows using monotone methods
Goorjian, P. M.; van Buskirk, R.
1981-01-01
Implicit approximate-factorization algorithms have been developed that use monotone methods for the calculation of steady and unsteady transonic flows governed by the small-disturbance-potential equation. These algorithms use the new Engquist-Osher switch in the type-dependent differencing in place of the standard Murman-Cole switch. The resulting algorithms are more stable; hence, calculations can be done more efficiently. For steady flows, the convergence rate is about 35% faster, and for unsteady flows the allowable time step is about 10 times larger. These improvements are achieved with no increase in computer storage and with only minor modifications in codes that use the Murman-Cole switch. Also an implicit algorithm has been developed for the steady full-potential equation in one-dimension, which uses monotone methods.
Problems in radiation shielding calculations with Monte Carlo methods
International Nuclear Information System (INIS)
The Monte Carlo method is a very useful tool for solving a large class of radiation transport problem. In contrast with deterministic method, geometric complexity is a much less significant problem for Monte Carlo calculations. However, the accuracy of Monte Carlo calculations is of course, limited by statistical error of the quantities to be estimated. In this report, we point out some typical problems to solve a large shielding system including radiation streaming. The Monte Carlo coupling technique was developed to settle such a shielding problem accurately. However, the variance of the Monte Carlo results using the coupling technique of which detectors were located outside the radiation streaming, was still not enough. So as to bring on more accurate results for the detectors located outside the streaming and also for a multi-legged-duct streaming problem, a practicable way of ''Prism Scattering technique'' is proposed in the study. (author)
The application of advanced rotor (performance) methods for design calculations
Energy Technology Data Exchange (ETDEWEB)
Bussel, G.J.W. van [Delft Univ. of Technology, Inst. for Wind Energy, Delft (Netherlands)
1997-08-01
The calculation of loads and performance of wind turbine rotors has been a topic for research over the last century. The principles for the calculation of loads on rotor blades with a given specific geometry, as well as the development of optimal shaped rotor blades have been published in the decades that significant aircraft development took place. Nowadays advanced computer codes are used for specific problems regarding modern aircraft, and application to wind turbine rotors has also been performed occasionally. The engineers designing rotor blades for wind turbines still use methods based upon global principles developed in the beginning of the century. The question what to expect in terms of the type of methods to be applied in a design environment for the near future is addressed here. (EG) 14 refs.
Improved transfer matrix methods for calculating quantum transmission coefficient.
Biswas, Debabrata; Kumar, Vishal
2014-07-01
Methods for calculating the transmission coefficient are proposed, all of which arise from improved nonreflecting WKB boundary conditions at the edge of the computational domain in one-dimensional geometries. In the first, the Schrödinger equation is solved numerically, while the second is a transfer matrix (TM) algorithm where the potential is approximated by steps, but with the first and last matrix modified to reflect the new boundary condition. Both methods give excellent results with first-order WKB boundary conditions. The third uses the transfer matrix method with third-order WKB boundary conditions. For the parabolic potential, the average error for the modified third-order TM method reduces by factor of 4100 over the unmodified TM method.
Triangulation methods in engineering measurement
Kyle, S. A.
1988-01-01
Industrial surveying and photogrammetry are being increasingly applied to the measurement of engineering objects which have typical dimensions in the range 2-100 metres. Both techniques are examples of the principle of triangulation. By applying photocrammetric concepts to surveying methods and vice-versa, a general approach is established which has a number of advantages. In particular. alternative strategies for constructing and analysing measurement networks are dev...
Calculations of pair production by Monte Carlo methods
Energy Technology Data Exchange (ETDEWEB)
Bottcher, C.; Strayer, M.R.
1991-01-01
We describe some of the technical design issues associated with the production of particle-antiparticle pairs in very large accelerators. To answer these questions requires extensive calculation of Feynman diagrams, in effect multi-dimensional integrals, which we evaluate by Monte Carlo methods on a variety of supercomputers. We present some portable algorithms for generating random numbers on vector and parallel architecture machines. 12 refs., 14 figs.
Calculations of pair production by Monte Carlo methods
International Nuclear Information System (INIS)
We describe some of the technical design issues associated with the production of particle-antiparticle pairs in very large accelerators. To answer these questions requires extensive calculation of Feynman diagrams, in effect multi-dimensional integrals, which we evaluate by Monte Carlo methods on a variety of supercomputers. We present some portable algorithms for generating random numbers on vector and parallel architecture machines. 12 refs., 14 figs
Directory of Open Access Journals (Sweden)
R. Sørensen
2006-01-01
Full Text Available The topographic wetness index (TWI, ln(a/tanβ, which combines local upslope contributing area and slope, is commonly used to quantify topographic control on hydrological processes. Methods of computing this index differ primarily in the way the upslope contributing area is calculated. In this study we compared a number of calculation methods for TWI and evaluated them in terms of their correlation with the following measured variables: vascular plant species richness, soil pH, groundwater level, soil moisture, and a constructed wetness degree. The TWI was calculated by varying six parameters affecting the distribution of accumulated area among downslope cells and by varying the way the slope was calculated. All possible combinations of these parameters were calculated for two separate boreal forest sites in northern Sweden. We did not find a calculation method that performed best for all measured variables; rather the best methods seemed to be variable and site specific. However, we were able to identify some general characteristics of the best methods for different groups of measured variables. The results provide guiding principles for choosing the best method for estimating species richness, soil pH, groundwater level, and soil moisture by the TWI derived from digital elevation models.
Thoughts on the Measurement and Calculation of Geogenetic Depth
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
@@ The method of determining the depth of geological events is based on the geobarometer method. According to this method, a depth to a certain position is obtained in such a way that the pressure at that position is divided by the specific weight (density) of the overlying rock formations, called the "W/SW" method in this paper. This method follows the principle of hydrostatics, assuming that rocks in this case are in a static fluid state (standard state) rather than a solid state. If so, only pressure could be measured from the rocks because the latter does not exist in a hydrostatic state. Unfortunately, a great deal of data in practice show this is not true.
Radiation protection, measurements and methods
International Nuclear Information System (INIS)
The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP)
X-ray tube output based calculation of patient entrance surface dose: validation of the method
Energy Technology Data Exchange (ETDEWEB)
Harju, O.; Toivonen, M.; Tapiovaara, M.; Parviainen, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland)
2003-06-01
X-ray departments need methods to monitor the doses delivered to the patients in order to be able to compare their dose level to established reference levels. For this purpose, patient dose per radiograph is described in terms of the entrance surface dose (ESD) or dose-area product (DAP). The actual measurement is often made by using a DAP-meter or thermoluminescent dosimeters (TLD). The third possibility, the calculation of ESD from the examination technique factors, is likely to be a common method for x-ray departments that do not have the other methods at their disposal or for examinations where the dose may be too low to be measured by the other means (e.g. chest radiography). We have developed a program for the determination of ESD by the calculation method and analysed the accuracy that can be achieved by this indirect method. The program calculates the ESD from the current time product, x-ray tube voltage, beam filtration and focus- to-skin distance (FSD). Additionally, for calibrating the dose calculation method and thereby improving the accuracy of the calculation, the x-ray tube output should be measured for at least one x-ray tube voltage value in each x-ray unit. The aim of the present work is to point out the restrictions of the method and details of its practical application. The first experiences from the use of the method will be summarised. (orig.)
Comparison between ASHRAE and ISO thermal transmittance calculation methods
DEFF Research Database (Denmark)
Blanusa, Petar; Goss, William P.; Roth, Hartwig;
2007-01-01
, Ontario, Canada, 1995], THERM [LBNL. THERM 2: PC Program for Analyzing Two-Dimensional Heat Transfer Through Building Products, LBL-37371, Windows and Delighting Group, Lawrence Berkeley National Laboratory, Berkeley, CA, 1998], ASHRAE SPC 142P [ASHRAE. Standard Method for Determining and Expressing...... is proportional to the glazing/frame sightline distance that is also proportional to the total glazing spacer length. An example calculation of the overall heat transfer and thermal transmittance (U-value or U-factor) using the two methods for a thermally broken, aluminum framed slider window is presented...
Fast Stiffness Matrix Calculation for Nonlinear Finite Element Method
Directory of Open Access Journals (Sweden)
Emir Gülümser
2014-01-01
Full Text Available We propose a fast stiffness matrix calculation technique for nonlinear finite element method (FEM. Nonlinear stiffness matrices are constructed using Green-Lagrange strains, which are derived from infinitesimal strains by adding the nonlinear terms discarded from small deformations. We implemented a linear and a nonlinear finite element method with the same material properties to examine the differences between them. We verified our nonlinear formulation with different applications and achieved considerable speedups in solving the system of equations using our nonlinear FEM compared to a state-of-the-art nonlinear FEM.
Hagedorn, Linda Serra
1998-01-01
A study explored two distinct methods of calculating a precise measure of gender-based wage differentials among college faculty. The first estimation considered wage differences using a formula based on human capital; the second included compensation for past discriminatory practices. Both measures were used to predict three specific aspects of…
Measurements and calculations of doses from radioactive particles
International Nuclear Information System (INIS)
Three Mile Island (TMI) and Tchernobyl reactor accidents have revealed the importance of the skin exposure to beta radiation produced by small high activity sources, named 'hot particles'. In nuclear power reactors, they may arise as small fragments of irradiated fuel or material which have been neutron activated by passing through the reactor co. In recent years, skin exposure to hot particles has been subject to different limitation criteria, formulated by AIEA, ICRP, NCRP working groups. The present work is the contribution of CEA Grenoble to a contract of the Commission of the European communities in cooperation with several laboratories: University of Birmingham, University of Toulouse and University of Montpellier with the main goal to check experiments and calculations of tissue dose from 60Co radioactive particles. This report is split up into two parts: hot particle dosimetry close to a 60Co spherical sample with an approximately 200 μm diameter, using a PTW extrapolation chamber model 233991; dose calculations from two codes: the Varskin Mod 2 computer code and the Hot 25 S2 Monte Carlo algorithm. The two codes lead to similar results; nevertheless there is a large discrepancy (of about 2) between calculations and PTW measurements which are higher by a factor of 1.9. At a 70 μm skin depth and for 1 cm2 irradiated area, the total (β + γ) tissue dose rate delivered by a spherical ( φ = 200 μm) 60Co source, in contact with skin, is of the order of 6.1 10-2 nGy s-1 Bq-1. (author)
Comparison of dose calculation methods for brachytherapy of intraocular tumors
Energy Technology Data Exchange (ETDEWEB)
Rivard, Mark J.; Chiu-Tsao, Sou-Tung; Finger, Paul T.; Meigooni, Ali S.; Melhus, Christopher S.; Mourtada, Firas; Napolitano, Mary E.; Rogers, D. W. O.; Thomson, Rowan M.; Nath, Ravinder [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Quality MediPhys LLC, Denville, New Jersey 07834 (United States); New York Eye Cancer Center, New York, New York 10065 (United States); Department of Radiation Oncology, Comprehensive Cancer Center of Nevada, Las Vegas, Nevada 89169 (United States); Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Department of Radiation Physics, University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030 (United States) and Department of Experimental Diagnostic Imaging, University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Physics, Elekta Inc., Norcross, Georgia 30092 (United States); Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520 (United States)
2011-01-15
Purpose: To investigate dosimetric differences among several clinical treatment planning systems (TPS) and Monte Carlo (MC) codes for brachytherapy of intraocular tumors using {sup 125}I or {sup 103}Pd plaques, and to evaluate the impact on the prescription dose of the adoption of MC codes and certain versions of a TPS (Plaque Simulator with optional modules). Methods: Three clinical brachytherapy TPS capable of intraocular brachytherapy treatment planning and two MC codes were compared. The TPS investigated were Pinnacle v8.0dp1, BrachyVision v8.1, and Plaque Simulator v5.3.9, all of which use the AAPM TG-43 formalism in water. The Plaque Simulator software can also handle some correction factors from MC simulations. The MC codes used are MCNP5 v1.40 and BrachyDose/EGSnrc. Using these TPS and MC codes, three types of calculations were performed: homogeneous medium with point sources (for the TPS only, using the 1D TG-43 dose calculation formalism); homogeneous medium with line sources (TPS with 2D TG-43 dose calculation formalism and MC codes); and plaque heterogeneity-corrected line sources (Plaque Simulator with modified 2D TG-43 dose calculation formalism and MC codes). Comparisons were made of doses calculated at points-of-interest on the plaque central-axis and at off-axis points of clinical interest within a standardized model of the right eye. Results: For the homogeneous water medium case, agreement was within {approx}2% for the point- and line-source models when comparing between TPS and between TPS and MC codes, respectively. For the heterogeneous medium case, dose differences (as calculated using the MC codes and Plaque Simulator) differ by up to 37% on the central-axis in comparison to the homogeneous water calculations. A prescription dose of 85 Gy at 5 mm depth based on calculations in a homogeneous medium delivers 76 Gy and 67 Gy for specific {sup 125}I and {sup 103}Pd sources, respectively, when accounting for COMS-plaque heterogeneities. For off
SOLAR OPACITY CALCULATIONS USING THE SUPER-TRANSITION-ARRAY METHOD
Energy Technology Data Exchange (ETDEWEB)
Krief, M.; Feigel, A.; Gazit, D., E-mail: menahem.krief@mail.huji.ac.il [The Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)
2016-04-10
A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.
Solar Opacity Calculations Using the Super-transition-array Method
Krief, M.; Feigel, A.; Gazit, D.
2016-04-01
A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation-convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.
Process control and optimization with simple interval calculation method
DEFF Research Database (Denmark)
Pomerantsev, A.; Rodionova, O.; Høskuldsson, Agnar
2006-01-01
Methods of process control and optimization are presented and illustrated with a real world example. The optimization methods are based on the PLS block modeling as well as on the simple interval calculation methods of interval prediction and object status classification. It is proposed to employ...... the series of expanding PLS/SIC models in order to support the on-line process improvements. This method helps to predict the effect of planned actions on the product quality and thus enables passive quality control. We have also considered an optimization approach that proposes the correcting actions...... data as a basis for modeling. On the other hand, the presented concept aims more at the process optimization than at the process control. Therefore, it is proposed to call such an approach as multivariate statistical process optimization (MSPO)....
IMAGE PROFILE AREA CALCULATION BASED ON CIRCULAR SAMPLE MEASUREMENT CALIBRATION
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
A practical approach of measurement calibration is presented for obtaining the true area of the photographed objects projected in the 2-D image scene. The calibration is performed using three circular samples with given diameters. The process is first to obtain the ratio mm/pixel in two orthogonal directions, and then use the obtained ratios with the total number of pixels scanned within projected area of the object of interest to compute the desired area. Compared the optically measured areas with their corresponding true areas, the results show that the proposed method is quite encouraging and the relevant application also proves the approach adequately accurate.
A Novel TRM Calculation Method by Probabilistic Concept
Audomvongseree, Kulyos; Yokoyama, Akihiko; Verma, Suresh Chand; Nakachi, Yoshiki
In a new competitive environment, it becomes possible for the third party to access a transmission facility. From this structure, to efficiently manage the utilization of the transmission network, a new definition about Available Transfer Capability (ATC) has been proposed. According to the North American ElectricReliability Council (NERC)’s definition, ATC depends on several parameters, i. e. Total Transfer Capability (TTC), Transmission Reliability Margin (TRM), and Capacity Benefit Margin (CBM). This paper is focused on the calculation of TRM which is one of the security margin reserved for any uncertainty of system conditions. The TRM calculation by probabilistic method is proposed in this paper. Based on the modeling of load forecast error and error in transmission line limitation, various cases of transmission transfer capability and its related probabilistic nature can be calculated. By consideration of the proposed concept of risk analysis, the appropriate required amount of TRM can be obtained. The objective of this research is to provide realistic information on the actual ability of the network which may be an alternative choice for system operators to make an appropriate decision in the competitive market. The advantages of the proposed method are illustrated by application to the IEEJ-WEST10 model system.
The new performance calculation method of fouled axial flow compressor.
Yang, Huadong; Xu, Hong
2014-01-01
Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds' law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail. PMID:25197717
The New Performance Calculation Method of Fouled Axial Flow Compressor
Directory of Open Access Journals (Sweden)
Huadong Yang
2014-01-01
Full Text Available Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds’ law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail.
Convergence and accuracy of numerical methods for trajectory calculations
International Nuclear Information System (INIS)
Computation of trajectories by a kinematic method requires the numerical solution of the differential equation by which the trajectory is defined. A widely used method is the iterative scheme of Petterssen which has second-order accuracy. The convergence and accuracy of this scheme is investigated for some simple flow types where analytical solutions are available. The results are discussed in comparison to other methods, especially a method similar to the Patterssen scheme, which has been recommended for use in semi-Lagrangian advection schemes. The truncation error in trajectory calculations should be kept about one order of magnitude smaller than the total uncertainty, which is mainly due to analysis errors and limited resolution of the wind data. It is shown that for trajectory calculations based on the typical output of current numerical weather prediction models or comparable data, this requires a time step 15% of the time step necessary to achieve convergence. If a fixed time step is used, it should not exceed about 0.5 h. Flexible time steps, based on the estimate of the truncation error which is provided by the difference between the first and the second iteration, are an attractive alternative. 26 refs., 8 figs
Calculation of VPP basing on functional analyzing method
Institute of Scientific and Technical Information of China (English)
Bai Kaixiang; Wang Dexun; Han Jiurui
2007-01-01
The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper. Functional analyzing method is a theoretical model of the VPP calculation which can eliminate the influence of the sail and board's size skillfully, so it can be regarded as a brief standard of the sailboard's VPP results. As a brief watery dynamical model, resistance on board can be regarded as a direct proportion to the square of the boat-velocity. The boat-velocities at the state of six wind-velocities (3 m/s-8 m/s) with angles of 25°-180° are obtained by calculating, which provides an important gist of the sailing-route's selection in upwind-sailing.
Decoherence of Entangled States Calculated by a Systematic Approximate Method
Institute of Scientific and Technical Information of China (English)
LIU Tao; FAN Yun-Xia; HUANG Shu-Weng; WANG Ke-Lin; WANG Yi
2007-01-01
In this paper the coherent-state approximation (CA) method is used to deal with the problem of the decoherence of the entangled states of two two-state systems. As the base of the discussion, the dissipation of one two-state system has been investigated at first. The improved results calculated by CA are given in the paper. It is shown that the right approaching behavior and scaling law have been obtained when CA is applied to the problem of dissipation of two two-state systems coupled with environment. The whole evolution process and calculated results of the decoherence of the entangled states show also the scaling law, right approaching behavior, and rich phenomenon.
Comparison of calculation and measurements of reaction rates in the outer regions of superphenix
International Nuclear Information System (INIS)
This paper brings together the results of two analyses of the Superphenix start-up measurements in the radial shield. Two different methods of calculation have been used based on SN transport theory (the PROPANE DO formulaire with the BISTRO code) and adjusted diffusion coefficients (the code SNAPSH using ADC method D). The PROPANE DO formulaire was found to give good agreement with the measured thermal flux both in the prediction of radial attenuation and in the reproduction of the axial profile. The ADC method was found to underestimate the attenuation. There were difficulties in reproducing the flux and neutron spectrum at the breeder/shield interface with both methods. This detailed comparison with measured values will assist in the formulation of recommended calculational routes for analysis of fast reactor shielding problems, an example of which has been the proposal of revised uncertainties for the PROPANE DO formulaire
A unique manual method for emergency offsite dose calculations
International Nuclear Information System (INIS)
This paper describes a manual method developed for performance of emergency offsite dose calculations for PP and L's Susquehanna Steam Electric Station. The method is based on a three-part carbonless form. The front page guides the user through selection of the appropriate accident case and inclusion of meteorological and effluent data data. By circling the applicable accident descriptors, the user circles the dose factors on pages 2 and 3 which are then simply multiplied to yield the whole body and thyroid dose rates at the plant boundary, two, five, and ten miles. The process used to generate the worksheet is discussed, including the method used to incorporate the observed terrain effects on airflow patterns caused by the Susquehanna River Valley topography
Tensile force correction calculation method for prestressed construction of tension structures
Institute of Scientific and Technical Information of China (English)
Xin ZHUO; Guo-fa ZHANG; Koichiro ISHIKAWA; Dao-an LOU
2008-01-01
Factors such as errors during the fabrication or construction of structural components and errors of calculation assumption or calculation methods,are very likely to cause serious deviation of many strings'actual prestressing forces from the designed values during tension structure construction or service period,and further to threaten the safety and reliability of the structure.Aiming at relatively large errors of the prestressing force of strings in a tension structure construction or service period,this paper proposes a new finite element method(FEM),the"tensile force correction calculation method".Based on the measured prestressing forces of the strings,this new method applies the structure from the zero prestressing force status approach to the measured prestressing force status for the first phase,and from the measured prestressing force status approach to the designed prestressing force status for the second phase.The construction tensile force correction value for each string can be obtained by multi-iteration with FEM.Using the results of calculation,the strings'tensile force correction by group and in batch will be methodic,simple and accurate.This new calculation method Can be applied to the prestressed correction construction simulation analysis for tension structures.
On the Methods for Calculating Annual Allowable Cut
Directory of Open Access Journals (Sweden)
V. А. Sokolov
2014-10-01
Full Text Available Crisis in supplying regions and the country related to available forest resources and low profitability of forest sector, as a whole, is an indicator of failure of the existing model of forest management and forest use organization in Russia at the present time. Many Russian regions, which are traditionally considered as forest industrial territories, face the challenge of lack of economically accessible forests. The forests are decreasing against a background of under exploitation of the annual allowable cut. This situation occurs in Siberia as well. In many cases, using calculated allowable cut will result in unsustainable harvest levels and a future decrease of accessible forest resources. Thus, the statement that «a volume of wood resource utilization is determined by allowable cut represented the scientifically grounded norm of sustainable forest use» is considered as no more than the declarative proposition. Modeling the normal forest, and using a formula of allowable cut calculation estimated for some decades based on the modeling, is totally unreliable and unreal. The long-term forecast should use analog methods, but it will hardly be sufficiently accurate and adequate to set norms. In order to estimate ecological and economic accessibility of forest resources, an algorithm was made, and a method and model were developed. This model is based on GIS-database and makes it possible to estimate accessibility of forest resources and to map it as well. The conclusion on necessity to determine annual allowable cut in two varieties was drawn following the procedures for calculating annual allowable cut. The first variety is silvicultural (according the currently used methods and the other one is economically accessible allowable cut, which could provide economic effective use of tradable mature wood, taking in to account ecological and economic accessibility of forest resources.
Study on calculation methods for the effective delayed neutron fraction
International Nuclear Information System (INIS)
The effective delayed neutron fraction βeff is one of the important neutronic parameters from a view point of a reactor kinetics. Several Monte-Carlo-based methods to estimate βeff have been proposed to date. In order to quantify the accuracy of these methods, we study calculation methods for βeff by analyzing various fast neutron systems including the bare spherical systems (Godiva, Jezebel, Skidoo, Jezebel-240), the reflective spherical systems (Popsy, Topsy, Flattop-23), MASURCA-R2 and MASURCA-ZONA2, and FCA XIX-1, XIX-2 and XIX-3. These analyses are performed by using SLAROM-UF and CBG for the deterministic method and MVP-II for the Monte Carlo method. We calculate βeff with various definitions such as the fundamental value β0, the standard definition, Nauchi's definition and Meulekamp's definition, and compare these results with each other. Through the present study, we find the following: The largest difference among the standard definition of βeff , Nauchi's βeff and Meulekamp's βeff is approximately 10%. The fundamental value β0 is quite larger than the others in several cases. For all the cases, Meulekamp's βeff is always higher than Nauchi's βeff. This is because Nauchi's βeff considers the average neutron multiplicity value per fission which is large in the high energy range (1MeV-10MeV), while the definition of Meulekamp's βeff does not include this parameter. Furthermore, we evaluate the multi-generation effect on βeff values and demonstrate that this effect should be considered to obtain the standard definition values of βeff. (author)
An accurate δf method for neoclassical transport calculation
International Nuclear Information System (INIS)
A δf method, solving drift kinetic equation, for neoclassical transport calculation is presented in detail. It is demonstrated that valid results essentially rely on the correct evaluation of marker density g in weight calculation. A general and accurate weighting scheme is developed without using some assumed g in weight equation for advancing particle weights, unlike the previous schemes. This scheme employs an additional weight function to directly solve g from its kinetic equation using the idea of δf method. Therefore the severe constraint that the real marker distribution must be consistent with the initially assumed g during a simulation is relaxed. An improved like-particle collision scheme is presented. By performing compensation for momentum, energy and particle losses arising from numerical errors, the conservations of all the three quantities are greatly improved during collisions. Ion neoclassical transport due to self-collisions is examined under finite banana case as well as zero banana limit. A solution with zero particle and zero energy flux (in case of no temperature gradient) over whole poloidal section is obtained. With the improvement in both like-particle collision scheme and weighting scheme, the δf simulation shows a significantly upgraded performance for neoclassical transport study. (author)
An accurate {delta}f method for neoclassical transport calculation
Energy Technology Data Exchange (ETDEWEB)
Wang, W.X.; Nakajima, N.; Murakami, S.; Okamoto, M. [National Inst. for Fusion Science, Toki, Gifu (Japan)
1999-03-01
A {delta}f method, solving drift kinetic equation, for neoclassical transport calculation is presented in detail. It is demonstrated that valid results essentially rely on the correct evaluation of marker density g in weight calculation. A general and accurate weighting scheme is developed without using some assumed g in weight equation for advancing particle weights, unlike the previous schemes. This scheme employs an additional weight function to directly solve g from its kinetic equation using the idea of {delta}f method. Therefore the severe constraint that the real marker distribution must be consistent with the initially assumed g during a simulation is relaxed. An improved like-particle collision scheme is presented. By performing compensation for momentum, energy and particle losses arising from numerical errors, the conservations of all the three quantities are greatly improved during collisions. Ion neoclassical transport due to self-collisions is examined under finite banana case as well as zero banana limit. A solution with zero particle and zero energy flux (in case of no temperature gradient) over whole poloidal section is obtained. With the improvement in both like-particle collision scheme and weighting scheme, the {delta}f simulation shows a significantly upgraded performance for neoclassical transport study. (author)
A New Method for Calculating Counts in Cells
Szapudi, I
1997-01-01
In the near future a new generation of CCD based galaxy surveys will enable high precision determination of the N-point correlation functions. The resulting information will help to resolve the ambiguities associated with two-point correlation functions thus constraining theories of structure formation, biasing, and Gaussianity of initial conditions independently of the value of $\\Omega$. As one the most successful methods to extract the amplitude of higher order correlations is based on measuring the distribution of counts in cells, this work presents an advanced way of measuring it with unprecedented accuracy. Szapudi and Colombi (1996, hereafter \\cite{sc96}) identified the main sources of theoretical errors in extracting counts in cells from galaxy catalogs. One of these sources, termed as measurement error, stems from the fact that conventional methods use a finite number of sampling cells to estimate counts in cells. This effect can be circumvented by using an infinite number of cells. This paper present...
The PC index: method of calculation and physical sense
Janzhura, A.; Troshichev, O.
2012-04-01
The PC index has been introduced [Troshichev and Andrezen, 1985; Troshichev et al., 1988] to characterize magnetic activity in the polar caps generated by the solar wind coupling with the magnetosphere. The concept of the antisunward convection within the polar cap, controlled by the interplanetary electric field EKL determined by Kan and Lee (1979), served as a basis for the method of the index calculation. Value of disturbances in the polar cap geomagnetic H and D (or X and Y) components form the basis for derivation of the PC index. The technique of PC index derivation consists of two separate procedures: (1) derivation of the statistically justified regression coefficients determining relationship between the coupling function EKL and vector of polar cap magnetic disturbance δF, and (2) calculation of PC indices by data on current δF values with use of the regression coefficients established in course of the first procedure. To exclude from examination the geomagnetic field changes unrelated to the solar wind variations the value of geomagnetic disturbance is calculated in reference to the quiet daily variation. The regression coefficients α (slope) and β (intersection) describing a linear link between values δF and EKL are calculated in combination with the optimal angle φ providing the highest correlation between δF and EKL. Parameters α, β and φ are derived based on the statistically justified sets of data. As a result the PC index corresponding to the value of coupling function EKL, irrespective of UT time, season and point of observation is determined. Validation of the PC proper derivation has been testified by the following requirements imposed on the calculated PCN and PCS indices: PCN and PCS indices should be consistent with the interplanetary electric field EKL; PCN and PCS indices should be in close agreement with each other irrespective of season and UT time; indices should not demonstrate seasonal variation; indices should not
DEFF Research Database (Denmark)
Sørensen, Stefan; Nielsen, Hans Ove
2002-01-01
In this paper we present comparison of different line and cable series impedance calculation methods, where the correction of a discovered PSCAD/EMIDC v.3.0.8 calculation error of the cable series impedance results n deviation under 0.1% instead of the previous method which gave approximately 10......% deviation to other methods. The correction is done by adjusting he earth return path impedance for the cable model, and will thereby form the basis for a future comparison with measured data from a real full scale earth fault experiment on a mixed line and cable network....
Ratio method of measuring W boson mass
Energy Technology Data Exchange (ETDEWEB)
Guo, Feng [Stony Brook Univ., NY (United States)
2010-08-01
This dissertation describes an alternative method of measuring the W boson mass in DØ experiment. Instead of extracting M_{W} from the fitting of W → ev fast Monte Carlo simulations to W → ev data as in the standard method, we make the direct fit of transverse mass between W → ev data and Z → ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (M_{W}/M_{Z}). Given the precisely measured Z boson mass, W mass is directly fitted from W → ev and Z → ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb^{-1} DØ Run IIa dataset, ratio method gives M_{W} = 80435 ± 43(stat) ± 26(sys) MeV.
Output calculation of electron therapy at extended SSD using an improved LBR method
Energy Technology Data Exchange (ETDEWEB)
Alkhatib, Hassaan A.; Gebreamlak, Wondesen T., E-mail: wondtassew@gmail.com; Wright, Ben W.; Neglia, William J. [South Carolina Oncology Associates, Columbia, South Carolina 29210 (United States); Tedeschi, David J. [Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208 (United States); Mihailidis, Dimitris [CAMC Cancer Center and Alliance Oncology, Charleston, West Virginia 25304 (United States); Sobash, Philip T. [The Medical University of South Carolina, Charleston, South Carolina 29425 (United States); Fontenot, Jonas D. [Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana 70809 (United States)
2015-02-15
Purpose: To calculate the output factor (OPF) of any irregularly shaped electron beam at extended SSD. Methods: Circular cutouts were prepared from 2.0 cm diameter to the maximum possible size for 15 × 15 applicator cone. In addition, two irregular cutouts were prepared. For each cutout, percentage depth dose (PDD) at the standard SSD and doses at different SSD values were measured using 6, 9, 12, and 16 MeV electron beam energies on a Varian 2100C LINAC and the distance at which the central axis electron fluence becomes independent of cutout size was determined. The measurements were repeated with an ELEKTA Synergy LINAC using 14 × 14 applicator cone and electron beam energies of 6, 9, 12, and 15 MeV. The PDD measurements were performed using a scanning system and two diodes—one for the signal and the other a stationary reference outside the tank. The doses of the circular cutouts at different SSDs were measured using PTW 0.125 cm{sup 3} Semiflex ion-chamber and EDR2 films. The electron fluence was measured using EDR2 films. Results: For each circular cutout, the lateral buildup ratio (LBR) was calculated from the measured PDD curve using the open applicator cone as the reference field. The effective SSD (SSD{sub eff}) of each circular cutout was calculated from the measured doses at different SSD values. Using the LBR value and the radius of the circular cutout, the corresponding lateral spread parameter [σ{sub R}(z)] was calculated. Taking the cutout size dependence of σ{sub R}(z) into account, the PDD curves of the irregularly shaped cutouts at the standard SSD were calculated. Using the calculated PDD curve of the irregularly shaped cutout along with the LBR and SSD{sub eff} values of the circular cutouts, the output factor of the irregularly shaped cutout at extended SSD was calculated. Finally, both the calculated PDD curves and output factor values were compared with the measured values. Conclusions: The improved LBR method has been generalized to
Huang, Jianhua
2012-07-01
There are three methods for calculating thermal insulation of clothing measured with a thermal manikin, i.e. the global method, the serial method, and the parallel method. Under the condition of homogeneous clothing insulation, these three methods yield the same insulation values. If the local heat flux is uniform over the manikin body, the global and serial methods provide the same insulation value. In most cases, the serial method gives a higher insulation value than the global method. There is a possibility that the insulation value from the serial method is lower than the value from the global method. The serial method always gives higher insulation value than the parallel method. The insulation value from the parallel method is higher or lower than the value from the global method, depending on the relationship between the heat loss distribution and the surface temperatures. Under the circumstance of uniform surface temperature distribution over the manikin body, the global and parallel methods give the same insulation value. If the constant surface temperature mode is used in the manikin test, the parallel method can be used to calculate the thermal insulation of clothing. If the constant heat flux mode is used in the manikin test, the serial method can be used to calculate the thermal insulation of clothing. The global method should be used for calculating thermal insulation of clothing for all manikin control modes, especially for thermal comfort regulation mode. The global method should be chosen by clothing manufacturers for labelling their products. The serial and parallel methods provide more information with respect to the different parts of clothing.
International Nuclear Information System (INIS)
Food consumption may account for upwards of 15% of U.S. per capita greenhouse gas emissions. Online carbon calculators can help consumers prioritize among dietary behaviors to minimize personal 'carbon footprints', leveraging against emissions-intensive industry practices. We reviewed the fitness of selected carbon calculators for measuring and communicating indirect GHG emissions from food consumption. Calculators were evaluated based on the scope of user behaviors accounted for, data sources, transparency of methods, consistency with prior data and effectiveness of communication. We found food consumption was under-represented (25%) among general environmental impact calculators (n = 83). We identified eight carbon calculators that accounted for food consumption and included U.S. users among the target audience. Among these, meat and dairy consumption was appropriately highlighted as the primary diet-related contributor to emissions. Opportunities exist to improve upon these tools, including: expanding the scope of behaviors included under calculations; improving communication, in part by emphasizing the ecological and public health co-benefits of less emissions-intensive diets; and adopting more robust, transparent methodologies, particularly where calculators produce questionable emissions estimates. Further, all calculators could benefit from more comprehensive data on the U.S. food system. These advancements may better equip these tools for effectively guiding audiences toward ecologically responsible dietary choices. (author)
Gradient type optimization methods for electronic structure calculations
Zhang, Xin; Wen, Zaiwen; Zhou, Aihui
2013-01-01
The density functional theory (DFT) in electronic structure calculations can be formulated as either a nonlinear eigenvalue or direct minimization problem. The most widely used approach for solving the former is the so-called self-consistent field (SCF) iteration. A common observation is that the convergence of SCF is not clear theoretically while approaches with convergence guarantee for solving the latter are often not competitive to SCF numerically. In this paper, we study gradient type methods for solving the direct minimization problem by constructing new iterations along the gradient on the Stiefel manifold. Global convergence (i.e., convergence to a stationary point from any initial solution) as well as local convergence rate follows from the standard theory for optimization on manifold directly. A major computational advantage is that the computation of linear eigenvalue problems is no longer needed. The main costs of our approaches arise from the assembling of the total energy functional and its grad...
NEW METHOD FOR CALCULATION OF STATISTIC MISTAKE IN MARKETING INVESTIGATIONS
Directory of Open Access Journals (Sweden)
V. A. Koldachiov
2008-01-01
Full Text Available An idea of a new method is that while breaking-down analysis sample in some sub-samples there is a probability that an actual value for general body will be inside the interval between the highest and lowest average meaning of sub-sample is much higher of the probability that the given value will be beyond the limits of the indicated interval. In this case a size of the interval appears to be less than analogous parameter while making calculation with the help of the Stewdent formula.Thus, it is possible to reach high accuracy in results of marketing investigations while preserving analysis sample size or reducing the necessary size of analysis sample while preserving level of statistical mistake.
A new method of calculating electrical conductivity with applications to natural waters
McCleskey, R. Blaine; Nordstrom, D. Kirk; Ryan, Joseph N.; Ball, James W.
2012-01-01
A new method is presented for calculating the electrical conductivity of natural waters that is accurate over a large range of effective ionic strength (0.0004–0.7 mol kg-1), temperature (0–95 °C), pH (1–10), and conductivity (30–70,000 μS cm-1). The method incorporates a reliable set of equations to calculate the ionic molal conductivities of cations and anions (H+, Li+, Na+, K+, Cs+, NH4+, Mg2+, Ca2+, Sr2+, Ba2+, F-, Cl-, Br-, SO42-, HCO3-, CO32-, NO3-, and OH-), environmentally important trace metals (Al3+, Cu2+, Fe2+, Fe3+, Mn2+, and Zn2+), and ion pairs (HSO4-, NaSO4-, NaCO3-, and KSO4-). These equations are based on new electrical conductivity measurements for electrolytes found in a wide range of natural waters. In addition, the method is coupled to a geochemical speciation model that is used to calculate the speciated concentrations required for accurate conductivity calculations. The method was thoroughly tested by calculating the conductivities of 1593 natural water samples and the mean difference between the calculated and measured conductivities was -0.7 ± 5%. Many of the samples tested were selected to determine the limits of the method and include acid mine waters, geothermal waters, seawater, dilute mountain waters, and river water impacted by municipal waste water. Transport numbers were calculated and H+, Na+, Ca2+, Mg2+, NH4+, K+, Cl-, SO42-, HCO3-, CO32-, F-, Al3+, Fe2+, NO3-, and HSO4- substantially contributed (>10%) to the conductivity of at least one of the samples. Conductivity imbalance in conjunction with charge imbalance can be used to identify whether a cation or an anion measurement is likely in error, thereby providing an additional quality assurance/quality control constraint on water analyses.
Measurements and Monte Carlo calculations of photon energy distributions in MAYAK PA workplaces.
Smetanin, M; Vasilenko, E; Semenov, M; Xanthos, S; Takoudis, G; Clouvas, A; Silva, J; Potiriadis, C
2008-01-01
Photon energy distributions were measured in different workplaces of the Mayak Production Association (MPA), which was the first plutonium production plant in the former Soviet Union. In situ gamma spectrometry measurements were performed with a portable germanium detector. The spectral stripping method is used for the conversion of the in situ gamma-ray spectra to photon fluence rate energy distribution. This method requires the simulation of the portable germanium detector, which has been performed based on the MCNP code of Los Alamos. Measured photon fluence rate energy distributions were compared with calculated photon energy distributions (with the MCNP code) in two different workplaces: in the first workplace the geometry exposure was known. On the contrary, in the second workplace, as in most workplaces of MPA, the exposure geometry was unknown. The results obtained from the comparison between the experimental and calculated photon fluence rate energy distributions are presented and discussed. PMID:18682405
Implementation of a method for calculating output factors in air for irregular fields
Energy Technology Data Exchange (ETDEWEB)
Suero Rodrigo, M. A.; Marques Frguela, E.
2011-07-01
The concept of output factor in air (Sc) was introduced to characterize the variation of the incident photon fluence per unit monitor with different settings of the collimator. The objective of this work is the implementation of the method proposed by Zhu et al. (2004) to calculate both as FCSc Sc and verification with the measurements performed in mini-mannequin.
International Nuclear Information System (INIS)
The kerma heat production density, tritum production density, and dose in a lithium-fluoride pile with a deuterium-tritum neutron source were calculated with a data processing code, UFO, from the pulse height distribution of a miniature NE213 neutron spectrometer, and compared with the values calculated with a Monte Carlo code, MORSE-CV. Both the UFO and MORSE-CV values agreed with the statistical error (less than 6%) of the MORSE-CV calculations, except for the outer-most point in the pile. The MORSE-CV values were slightly smaller than the UFO values for almost all cases, and this tendency increased with increasing distance from the neutron source
Nanofibril Alignment in Flow Focusing: Measurements and Calculations.
Håkansson, Karl M O; Lundell, Fredrik; Prahl-Wittberg, Lisa; Söderberg, L Daniel
2016-07-14
Alignment of anisotropic supermolecular building blocks is crucial to control the properties of many novel materials. In this study, the alignment process of cellulose nanofibrils (CNFs) in a flow-focusing channel has been investigated using small-angle X-ray scattering (SAXS) and modeled using the Smoluchowski equation, which requires a known flow field as input. This flow field was investigated experimentally using microparticle-tracking velocimetry and by numerically applying the two-fluid level set method. A semidilute dispersion of CNFs was modeled as a continuous phase, with a higher viscosity as compared to that of water. Furthermore, implementation of the Smoluchowski equation also needed the rotational Brownian diffusion coefficient, which was experimentally determined in a shear viscosity measurement. The order of the nanofibrils was found to increase during extension in the flow-focusing channel, after which rotational diffusion acted on the orientation distribution, driving the orientation of the fibrils toward isotropy. The main features of the alignment and dealignment processes were well predicted by the numerical model, but the model overpredicted the alignment at higher rates of extension. The apparent rotational diffusion coefficient was seen to increase steeply as the degree of alignment increased. Thus, the combination of SAXS measurements and modeling provides the necessary framework for quantified studies of hydrodynamic alignment, followed by relaxation toward isotropy. PMID:27294285
Nanofibril Alignment in Flow Focusing: Measurements and Calculations.
Håkansson, Karl M O; Lundell, Fredrik; Prahl-Wittberg, Lisa; Söderberg, L Daniel
2016-07-14
Alignment of anisotropic supermolecular building blocks is crucial to control the properties of many novel materials. In this study, the alignment process of cellulose nanofibrils (CNFs) in a flow-focusing channel has been investigated using small-angle X-ray scattering (SAXS) and modeled using the Smoluchowski equation, which requires a known flow field as input. This flow field was investigated experimentally using microparticle-tracking velocimetry and by numerically applying the two-fluid level set method. A semidilute dispersion of CNFs was modeled as a continuous phase, with a higher viscosity as compared to that of water. Furthermore, implementation of the Smoluchowski equation also needed the rotational Brownian diffusion coefficient, which was experimentally determined in a shear viscosity measurement. The order of the nanofibrils was found to increase during extension in the flow-focusing channel, after which rotational diffusion acted on the orientation distribution, driving the orientation of the fibrils toward isotropy. The main features of the alignment and dealignment processes were well predicted by the numerical model, but the model overpredicted the alignment at higher rates of extension. The apparent rotational diffusion coefficient was seen to increase steeply as the degree of alignment increased. Thus, the combination of SAXS measurements and modeling provides the necessary framework for quantified studies of hydrodynamic alignment, followed by relaxation toward isotropy.
A Method of Calculating Motion Error in a Linear Motion Bearing Stage
Directory of Open Access Journals (Sweden)
Gyungho Khim
2015-01-01
Full Text Available We report a method of calculating the motion error of a linear motion bearing stage. The transfer function method, which exploits reaction forces of individual bearings, is effective for estimating motion errors; however, it requires the rail-form errors. This is not suitable for a linear motion bearing stage because obtaining the rail-form errors is not straightforward. In the method described here, we use the straightness errors of a bearing block to calculate the reaction forces on the bearing block. The reaction forces were compared with those of the transfer function method. Parallelism errors between two rails were considered, and the motion errors of the linear motion bearing stage were measured and compared with the results of the calculations, revealing good agreement.
Comparison of calculated and measured foliar O{sub 3} flux in crop and forest species
Energy Technology Data Exchange (ETDEWEB)
Grulke, N.E. [USDA Forest Service, 4955 Canyon Crest Drive, Riverside, CA 92507 (United States)]. E-mail: ngrulke@fs.fed.us; Paoletti, E. [IPP-CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Florence (Italy); Heath, R.L. [Botany and Plant Sciences Department, University of California, Riverside, CA 92521 (United States)
2007-04-15
We designed a new gas exchange system that concurrently measures foliar H{sub 2}O, O{sub 3}, and CO{sub 2} flux (HOC flux system) while delivering known O{sub 3} concentrations. Stomatal responses of three species were tested: snapbean, and seedlings of California black oak (deciduous broadleaf) and blue oak (evergreen broadleaf). Acute O{sub 3} exposure (120-250 ppb over an hour) was applied under moderate light and low vapor pressure deficits during near steady state conditions. The rate of stomatal closure was measured when the whole plant was placed in the dark. An adjacent leaf on each plant was also concurrently measured in an O{sub 3}-free cuvette. Under some conditions, direct measurements and calculated foliar O{sub 3} flux were within the same order of magnitude; however, endogenously low gs or O{sub 3} exposure-induced depression of gs resulted in an overestimation of calculated O{sub 3} fluxes compared with measured O{sub 3} fluxes. Sluggish stomata in response to light extinction with concurrent O{sub 3} exposure, and incomplete stomatal closure likewise underestimated measured O{sub 3} flux. - Using a new system to concurrently measure H{sub 2}O, O{sub 3}, and CO{sub 2} flux, the conventional method of calculating O{sub 3} flux generally overestimated direct measures by 25-50%.
Energy Technology Data Exchange (ETDEWEB)
Homb, Anders; Uvsloekk, Sivert
2012-11-01
SINTEF has carried out a project for Cultural Heritage and Enova to document specific qualities of energy-efficient and preservable windows. The work has been based on an older type two-rams window with simple frames and one glass divided into three squares of horizontal crossbars. There were produced two kinds of commodity window, respectively, with single glazing with Insulating. Measurements and calculations have been performed with two different distances from the outer glass to the last frame. The project had the following contents: Measurements of the U-value, Calculation of U-value of accurate and simplified method, Measurements of air density and drying ability, Measurement and evaluation of sound insulation, Estimation of the heat balance (eb)
Hamiltonian lattice field theory: Computer calculations using variational methods
International Nuclear Information System (INIS)
I develop a variational method for systematic numerical computation of physical quantities -- bound state energies and scattering amplitudes -- in quantum field theory. An infinite-volume, continuum theory is approximated by a theory on a finite spatial lattice, which is amenable to numerical computation. I present an algorithm for computing approximate energy eigenvalues and eigenstates in the lattice theory and for bounding the resulting errors. I also show how to select basis states and choose variational parameters in order to minimize errors. The algorithm is based on the Rayleigh-Ritz principle and Kato's generalizations of Temple's formula. The algorithm could be adapted to systems such as atoms and molecules. I show how to compute Green's functions from energy eigenvalues and eigenstates in the lattice theory, and relate these to physical (renormalized) coupling constants, bound state energies and Green's functions. Thus one can compute approximate physical quantities in a lattice theory that approximates a quantum field theory with specified physical coupling constants. I discuss the errors in both approximations. In principle, the errors can be made arbitrarily small by increasing the size of the lattice, decreasing the lattice spacing and computing sufficiently long. Unfortunately, I do not understand the infinite-volume and continuum limits well enough to quantify errors due to the lattice approximation. Thus the method is currently incomplete. I apply the method to real scalar field theories using a Fock basis of free particle states. All needed quantities can be calculated efficiently with this basis. The generalization to more complicated theories is straightforward. I describe a computer implementation of the method and present numerical results for simple quantum mechanical systems
Renewable energy: Method and measures
International Nuclear Information System (INIS)
The thesis presents various possibilities for renewable energy in Norway. The wind power would give a practical and economic alternative. The external costs for the wind power would be moderate. In chapter 3 the utility cost analysis for renewable alternatives are studied relative to the macroeconomic efficiency. Some methodical problems and how these analyses are used are reviewed. In the practical utility cost analyses wind power is studied relative to gas power which is the non-renewable alternative present in Norway today. A qualitative part is included. It is not possible to determine whether wind power is preferable to gas power in the macroeconomic perspective. Wind power would be the choice if high environmental and CO2 cleaning costs are expected. The first conclusion to be drawn is that it is difficult to decide whether wind power is the best solution based on cost benefit analysis. However, the alternative seems to be quite robust in the analysis. Due to the central position the energy supplies have in the society this business should be heavily regulated. The sector is also overtaxed as a reduction in consumption is desired. The analysis shows that the system does not function perfectly. The thesis surveys various measures for improving the renewable energy supply and focuses on the wind power. A model for and analysis of the measures are carried out and resulted in a second conclusion. The measures have various properties as to the influence on the market. A subsidy is a fine measure for stimulation production of green power while a tax reduces efficiently the production of black power. A system with green licenses in combination with a subsidy and a tax would be preferable as to increasing the part of renewable energy of the total production. It is therefore necessary to have clearly defined goals and use suitable measures for achieving them. The costs of wind power is falling and it would therefore soon be macroeconomic profitable. It is also
Integrating The Abc Method Of Costs Calculation And Cash Value Added
Marius Sorin DINCA; Gheorghita DINCA
2010-01-01
In our paper we intend to explore the possibility of integrating the ABC method of cost calcula-tion with cash based value measure, i.e. the Cash Value Added. Our purpose is to develop an instrument for the management of productive companies that will allow them to administrate the proc-ess of value creation at the level of individual products or services. The activity based costing (ABC) method of cost calculation can be extended to the way of allo-cating the capital costs to individual prod...
Measurement and Monte Carlo Calculation of Waste Drum Filled With Radioactive Aqueous Solution
Institute of Scientific and Technical Information of China (English)
XU; Li-jun; ZHANG; Wei-dong; YE; Hong-sheng; LIN; Min; CHEN; Xi-lin; GUO; Xiao-qing
2012-01-01
<正>Theoretically the best calibrating source of gamma scan system (SGS) is a waste drum filled with uniform distribution of medium and radioactive nuclides. However, in reality, waste drums usually full of solid substance, which are difficult to be prepared in a completely uniformly distributed state. To reduce measurement uncertainty of the radioactivity of waste drums prepared using the method of shell source, a waste drum filled with radioactive aqueous solution was prepared. Besides, its radioactivity was measured by a SGS device and calculated using Monte Carlo method to verify the exact geometric model, which
BNCT dose calculation in irregular fields using the sector integration method
Energy Technology Data Exchange (ETDEWEB)
Blaumann, H.R. E-mail: blaumann@cab.cnea.gov.ar; Sanz, D.E.; Longhino, J.M.; Larrieu, O.A. Calzetta
2004-11-01
Irregular fields for boron neutron capture therapy (BNCT) have been already proposed to spare normal tissue in the treatment of superficial tumors. This added dependence would require custom measurements and/or to have a secondary calculation system. As a first step, we implemented the sector-integration method for irregular field calculation in a homogeneous medium and on the central beam axis. The dosimetric responses (fast neutron and photon dose and thermal neutron flux), are calculated by sector integrating the measured responses of circular fields over the field boundary. The measurements were carried out at our BNCT facility, the RA-6 reactor (Argentina). The input data were dosimetric responses for circular fields measured at different depths in a water phantom using ionisation and activation techniques. Circular fields were formed by shielding the beam with two plates: borated polyethilene plus lead. As a test, the dosimetric responses of a 7x4 cm{sup 2} rectangular field, were measured and compared to calculations, yielding differences less than 3% in equivalent dose at any depth indicating that the tool is suitable for redundant calculations.
BNCT dose calculation in irregular fields using the sector integration method.
Blaumann, H R; Sanz, D E; Longhino, J M; Larrieu, O A Calzetta
2004-11-01
Irregular fields for boron neutron capture therapy (BNCT) have been already proposed to spare normal tissue in the treatment of superficial tumors. This added dependence would require custom measurements and/or to have a secondary calculation system. As a first step, we implemented the sector-integration method for irregular field calculation in a homogeneous medium and on the central beam axis. The dosimetric responses (fast neutron and photon dose and thermal neutron flux), are calculated by sector integrating the measured responses of circular fields over the field boundary. The measurements were carried out at our BNCT facility, the RA-6 reactor (Argentina). The input data were dosimetric responses for circular fields measured at different depths in a water phantom using ionisation and activation techniques. Circular fields were formed by shielding the beam with two plates: borated polyethilene plus lead. As a test, the dosimetric responses of a 7x4 cm(2) rectangular field, were measured and compared to calculations, yielding differences less than 3% in equivalent dose at any depth indicating that the tool is suitable for redundant calculations.
IPR CURVE CALCULATING FOR A WELL PRODUCING BY INTERMITTENT GAS-LIFT METHOD
Directory of Open Access Journals (Sweden)
Zoran Mršić
2009-12-01
Full Text Available Master degree thesis (Mršić Z., 2009 shows the detailed procedure of calculating inflow performance curve for intermittent gas lift, based entirely on the data measured at surface. This article explains the detailed approach of the mentioned research and the essence of the results and observations acquired during the study. To evaluate the proposed method of calculating the average bottom hole flowing pressure (BHFP as the key parameter of inflow performance calculation, downhole pressure surveys have been conducted in three producing wells at Šandrovac and Bilogora oil fields: Šandrovac-75α, Bilogora-52 and Šandrovac-34. Absolute difference between measured and calculated values of average BHFP for first two wells was Δp=0,64 bar and Δp=0,06 bar while calculated relative error was εr=0,072 and εr=0,0038 respectively. Due to gas-lift valve malfunction in well Šandrovac-34, noticed during downhole pressure survey, value of calculated BHFP cannot be considered correct to compare with measured value. Based on the measured data the information have been revealed about actual values of a certain intermittent gas lift parameters that are usually assumed based on experience gained values or are calculated using empirical equations given in literature. The significant difference has been noticed for a parameter t2. The length of a minimum pressure period for which the measured values were in range of 10,74 min up to 16 min, while empirical equation gives values in the range of 1,23 min up to 1,75 min. Based on measured values of above mentioned parameter a new empirical equation has been established (the paper is published in Croatian.
Calculating magnetic shielding effectiveness for high-power dc comparator by magnetic circuit method
Institute of Scientific and Technical Information of China (English)
WANG Xiao-wei; REN Shi-yan
2007-01-01
Magnetic shielding is very important in the design of a high-power dc comparator. This paper addressed the application of magnetic circuit method to calculate the magnetic shielding effectiveness of high-power dc comparators when an external radial magnetic field is added. The mathematical relationship between the magnetic shielding effectiveness and the parameters of the magnetic shielding body were obtained. To verify the validity of the calculation method, we developped a procedure to measure the magnetic shielding effectiveness of the magnetic body by measuring the induction voltage of the detection winding instead of the magnetic intensity at a point in the magnetic shielding body, making the manipulation much easier. The result calculated with the magnetic circuit method turns out to be closer to the measured one compared with that calculated with a conventional algorithm proposed by Ren, suggesting that the magnetic circuit method is an applicable tool for estimating the toroidal cavity magnetic shielding effectiveness of a heavy current comparator when a radial magnetic field is added.
A Simplified Method to Calculate the Wet Bulb Globe Temperature(WBGT)
Institute of Scientific and Technical Information of China (English)
ZHANG Lei; MENG Qing-lin; ZHAO Li-hua; ZHANG Yu-feng
2009-01-01
Wet bulb globe temperature(WBGT) is a comprehensive index obtained mainly from three pa-rameters:black globe temperature(Tg),wet bulb temperature(Tw),and dry bulb temperature(Ta).While in field observation and numerical simulation,black globe temperature and wet bulb temperature were not easy to obtain, so WBGT was difficult to measure and calculate directly.In order to solve this problem,air dry bulb temperature, wet bulb temperature,globe temperature,relative humidity,mean air velocity,solar radiation and wet bulb globe temperature were collected during the summer(July)in Guangzhou.Correlation analysis and regression analysis were used to get a simplified method to calculate WBGT.The results showed that dry bulb temperature,relative humidity,solar radiation and WBGT were interrelated to some extent.These three pa-rameters could be used in the simplified method to predict WBGT,and the linear correlation and precision of this model were high.In addition,we used the measured data to verify the simplified method,and the results showed that the error of the calculated value and the measured value was all below 5%,which means the simpli-fied calculating method is feasible and can be used in field observation and simulation research of urban thermal environment.
Effective method for calculation of the analytic QCD coupling constant
Alekseev, A Yu
2002-01-01
The analytic running coupling of strong interaction alpha sub a sub n for initial standard perturbative approximations up to three-loop order is studied. The nonperturbative contributions to alpha sub a sub n are obtained in an explicit form. They are shown to be represented in the form of the expansion in the inverse powers of Euclidean momentum squared. It is shown that two-loop and three-loop-order corrections result in partial compensation of one-loop-order leading in the ultraviolet region nonperturbative contribution of the form 1/q sup 2. On basis of the stated expansion the effective method for calculation of the analytic running coupling is developed for all q > LAMBDA. The comparative analysis of the perturbative and nonperturbative contributions is carried out in the momentum dependence of alpha sub a sub n and its perturbative component for one - three-loop cases leads to a conclusion on higher loop stability of the analytic running coupling and its low dependence on the n sub f -threshold matchin...
Automated Methods Of Corrosion Measurements
DEFF Research Database (Denmark)
Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch;
1997-01-01
The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....
CALCULATION OF MILL RIGIDITY BY THREE DIMENSION CONTACT BOUNDARY ELEMENT METHOD
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Vertical rigidity of the space self-adaptive 530 high rigidity mill is calculated by applying the boundary element method (BEM) of three-dimension elastic contact problem,which can update the existed deforming separation calculating theory and corresponding methods of material mechanics,elastic mechanics and finite element method.The method has less hypotheses and stronger synthesis in contact-type calculating model.The advantages of the method are high calculating rate,high calculating accuracy,etc..
Directory of Open Access Journals (Sweden)
Jie Yang
2011-09-01
Full Text Available We report a relatively precise method of conductivity measurement in a diamond anvil cell with axis symmetrical electrodes and finite difference calculation. The axis symmetrical electrodes are composed of two parts: one is a round thin-film electrode deposited on diamond facet and the other is the inside wall of metal gasket. Due to the asymmetrical configuration of the two electrodes, finite difference method can be applied to calculate the conductivity of sample, which can reduce the measurement error.
The mechanical measuring method of welding heat source efficiency
Institute of Scientific and Technical Information of China (English)
Zhang Jianqiang; Zhang Guodong; He Jie; Wang Chengquan; Chen Bingquan
2007-01-01
Based on the principle of residual deformation induced by superposition of the welding residual stress and working stress, the welding heat source efficiency has been determined by measuring displacement changes of specimens under loading and unloading in tensile tests, and combining with calculating welding parameters. Meanwhile, the welding heat source efficiencies obtained are compared with those of the measuring-calculating method. The research results show that the welding heat source efficiencies are almost the same as those obtained by the measuring-calculating method. Therefore, the welding heat source efficiency can be determined accurately by this method, and a new determining method of the heat source efficiency for the welding heat process calculating has been provided.
Intraocular lens power calculations using a Scheimpflug camera to measure corneal power.
Xu, K; Hao, Y; Qi, H
2014-07-01
We measured corneal power using an Oculus Pentacam(®) to assess its accuracy for calculating intraocular lens (IOL) power after myopic refractive surgery. A series of corneal power measurements were performed on 22 patients (43 eyes) who had undergone myopic refractive surgery. In 37 of the 43 eyes, phacoemulsification and IOL implantation subsequently were performed. Conventional keratometry and three corneal measurements (mean true net power, central true net power, and 4.5 mm equivalent K reading) obtained using a Pentacam were analyzed and compared to values derived from the clinical history method. Prediction errors of three Pentacam corneal power measurements inserted in third generation IOL formulas also were compared. Analysis of the variance showed that only two Pentacam corneal measurements, mean true net power and central true net power, were not significantly different from those of the clinical history method. Mean true net power was correlated more closely with the clinical history method corneal power than other corneal power values. The one-sample t-test showed that of three Pentacam corneal measurements combined with third-generation formulas, only the mean true net power inserted in the SRK/T implant power calculation formula was not significantly different from zero. The percentages of eyes within ± 0.50 D and ± 1.00 D of the refractive prediction error of this method were 67.6% and 86.5%, respectively. Mean true net power inserted in the SRK/T formula can be used to calculate directly IOL power after myopic refractive surgery.
Calculation method of quantum efficiency to TiO2 nanocrystal photocatalysis reaction
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The quantum yield is an important factor to evaluate the efficiency of photoreactor. This article gives an overall calculation method of the quantum efficiency(ф) and the apparent quantum efficiency(ф2) to the TiO2/UV photocatalysis system. Furthermore, for the immobility system (IS), the formulation of the faction of light absorbed by the TiO2 thin film is proposed so as to calculate the quantum efficiency by using the measured value and theoretic calculated value of transmissivity (T). For the suspension system(SS), due to the difficulty to obtain the absorption coefficient (α) of TiO2 particulates, the quantum efficiency is calculated by means of the relative photonic efficiency (ξr) and the standard quantum yield (фstandard).
Solar particle events observed at Mars: dosimetry measurements andmodel calculations
Energy Technology Data Exchange (ETDEWEB)
Cleghorn, Timothy F.; Saganti, Premkumar; Zeitlin, Cary J.; Cucinotta, Francis A.
2004-12-01
During the period from March 13, 2002 to mid-September, 2002, six solar particle events (SPE) were observed by the MARIE instrument onboard the Odyssey Spacecraft in Martian Orbit. These events were observed also by the GOES 8 satellite in Earth orbit, and thus represent the first time that the same SPE have been observed at these separate locations. The characteristics of these SPE are examined, given that the active regions of the solar disc from which the event originated can usually be identified. The dose rates at Martian orbit are calculated, both for the galactic and solar components of the ionizing particle radiation environment. The dose rates due to galactic cosmic rays (GCR) agree well with the HZETRN model calculations.
Zhong, Zhaopeng; Talamo, Alberto; Gohar, Yousry
2013-07-01
The effective delayed neutron fraction β plays an important role in kinetics and static analysis of the reactor physics experiments. It is used as reactivity unit referred to as "dollar". Usually, it is obtained by computer simulation due to the difficulty in measuring it experimentally. In 1965, Keepin proposed a method, widely used in the literature, for the calculation of the effective delayed neutron fraction β. This method requires calculation of the adjoint neutron flux as a weighting function of the phase space inner products and is easy to implement by deterministic codes. With Monte Carlo codes, the solution of the adjoint neutron transport equation is much more difficult because of the continuous-energy treatment of nuclear data. Consequently, alternative methods, which do not require the explicit calculation of the adjoint neutron flux, have been proposed. In 1997, Bretscher introduced the k-ratio method for calculating the effective delayed neutron fraction; this method is based on calculating the multiplication factor of a nuclear reactor core with and without the contribution of delayed neutrons. The multiplication factor set by the delayed neutrons (the delayed multiplication factor) is obtained as the difference between the total and the prompt multiplication factors. Using Monte Carlo calculation Bretscher evaluated the β as the ratio between the delayed and total multiplication factors (therefore the method is often referred to as the k-ratio method). In the present work, the k-ratio method is applied by Monte Carlo (MCNPX) and deterministic (PARTISN) codes. In the latter case, the ENDF/B nuclear data library of the fuel isotopes (235U and 238U) has been processed by the NJOY code with and without the delayed neutron data to prepare multi-group WIMSD neutron libraries for the lattice physics code DRAGON, which was used to generate the PARTISN macroscopic cross sections. In recent years Meulekamp and van der Marck in 2006 and Nauchi and Kameyama
Modified methods of stellar magnetic field measurements
Kholtygin, A F
2013-01-01
The standard methods of the magnetic field measurement, based on an analysis of the relation between the Stokes $V$-parameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operator $\\hat{L}$ to the both sides of this relation. As the operator $\\hat{L}$, the operator of the wavelet transform with DOG-wavelets is used. The key advantage of the proposed method is an effective suppression of the noise contribution to the line profile and the Stokes parameter $V$. The efficiency of the method has been studied using the model line profiles with various noise contributions. To test the proposed method, the spectropolarimetric observations of the A0-type star $\\alpha^2\\,$ CVn, young O-type star $\\theta^1$ Ori C and A0 supergiant HD 92207 were used. The longitudinal magnetic field strengths for these stars calculated by our method appeared to be in a good agreement with those determined by other methods.
Phonon Measurements and Model Calculations for Naphtalene-d8
DEFF Research Database (Denmark)
Mackenzie, Gordon A.; Pawley, G. S.; Dietrich, O. W.
1977-01-01
Measurements of the phonon dispersion curves in naphthalene-d8, (deuteration >99%), taken at 77K are presented. The experiments were done on two crystals, using the triple-axis neutron spectrometers at the medium flux reactor, DR3 at Riso. Most of the external or lattice modes have been measured ...
Dynamic Calculation Method of Beam System Under Low Velocity Impact
Institute of Scientific and Technical Information of China (English)
LI Wen-pei; WANG De-rong; SONG Chun-ming; WANG Ming-yang
2008-01-01
The beating beams and the supporting beams under low velocity impact may be in four different strain stages of deformation depending on the impact intensity and beam structure strength. Based on the different judging conditions of deformation stages, the corresponding calculation models are proposed, the calculation formulae for the determination of the impact force and the beam's lateral displacement are obtained. Calculation shows that the beam's total deflection is small when the flexibility of the supporting component is high and the effect of diminishing deflection disappears almost when the stiffness of the supporting component is high.
Calculation of Industrial Enterprise Ventilation System by Network Integral Method
Directory of Open Access Journals (Sweden)
Mihienkova Evgeniya I.
2016-01-01
Full Text Available This paper describe a ventilation system calculation of the technology building industrial enterprise. On the basis of the calculation model for the enterprise offered technical decision of ventilation systems, subject to a compliance exchange multiplicity, purification efficiency, decontamination from the work area; provided the required volume of gas extraction from process equipment according to the sanitary standards and environmental requirements. Produced selection of ventilation equipment parameters, solved the problem of the air exchange balancing between ventilation systems to prevent the emergence of parasitic flows between the rooms building. SigmaNet software package was used for the implement the calculation.
Analysis of shielding calculation methods for 16- and 64-slice computed tomography facilities
Energy Technology Data Exchange (ETDEWEB)
Moreno, C; Cenizo, E; Bodineau, C; Mateo, B; Ortega, E M, E-mail: c_morenosaiz@yahoo.e [Servicio de RadiofIsica Hospitalaria, Hospital Regional Universitario Carlos Haya, Malaga (Spain)
2010-09-15
The new multislice computed tomography (CT) machines require some new methods of shielding calculation, which need to be analysed. NCRP Report No. 147 proposes three shielding calculation methods based on the following dosimetric parameters: weighted CT dose index for the peripheral axis (CTDI{sub w,per}), dose-length product (DLP) and isodose maps. A survey of these three methods has been carried out. For this analysis, we have used measured values of the dosimetric quantities involved and also those provided by the manufacturer, making a comparison between the results obtained. The barrier thicknesses when setting up two different multislice CT instruments, a Philips Brilliance 16 or a Philips Brilliance 64, in the same room, are also compared. Shielding calculation from isodose maps provides more reliable results than the other two methods, since it is the only method that takes the actual scattered radiation distribution into account. It is concluded therefore that the most suitable method for calculating the barrier thicknesses of the CT facility is the one based on isodose maps. This study also shows that for different multislice CT machines the barrier thicknesses do not necessarily become bigger as the number of slices increases, because of the great dependence on technique used in CT protocols for different anatomical regions.
Directory of Open Access Journals (Sweden)
Seied R Mahdavi
2012-01-01
Full Text Available Aims: The objective of this study is to evaluate the accuracy of a treatment planning system (TPS for calculating the dose distribution parameters in conformal fields (CF. Dosimetric parameters of CF′s were compared between measurement, Monte Carlo simulation (MCNP4C and TPS calculation. Materials and Methods: Field analyzer water phantom was used for obtaining percentage depth dose (PDD curves and beam profiles (BP of different conformal fields. MCNP4C was used to model conformal fields dose specification factors and head of linear accelerator varian model 2100C/D. Results: Results showed that the distance to agreement (DTA and dose difference (DD of our findings were well within the acceptance criteria of 3 mm and 3%, respectively. Conclusions: According to this study it can be revealed that TPS using equivalent tissue air ratio calculation method is still convenient for dose prediction in non small conformal fields normally used in prostate radiotherapy. It was also showed that, since there is a close correlation with Monte Carlo simulation, measurements and TPS, Monte Carlo can be further confirmed for implementation and calculation dose distribution in non standard and complex conformal irradiation field for treatment planning systems.
Energy Labelling of Glazings and Windows in Denmark: Calculated and Measured Values
DEFF Research Database (Denmark)
Duer, Karsten; Svendsen, Svend; Mogensen, Morten Møller;
2002-01-01
The influence of windows on the energy consumption in buildings is well known and in order to encourage the development and the appropriate use of high performance glazings and windows in Denmark, an Energy Labelling and Rating system is being developed. During this work a need for establishing a...... common and well-defined method to characterise the performance of glazings and windows on the Danish market has been recognised. This paper gives a short description of the Danish Energy Labelling and Rating system for glazings and windows, which was put into operation during 2000. Furthermore the...... results of a comparison between measured and calculated thermal transmittance for five different window types are given. The calculations on the glazing part have been performed in five different programmes (WIS, WINDOW, VISION, CALUMEN and GLAD99). The calculations on the frame part have been performed...
A New Efficient Method for Calculating Similarity Between Web Services
Directory of Open Access Journals (Sweden)
T. RACHAD
2014-08-01
Full Text Available Web services allow communication between heterogeneous systems in a distributed environment. Their enormous success and their increased use led to the fact that thousands of Web services are present on the Internet. This significant number of Web services which not cease to increase has led to problems of the difficulty in locating and classifying web services, these problems are encountered mainly during the operations of web services discovery and substitution. Traditional ways of search based on keywords are not successful in this context, their results do not support the structure of Web services and they consider in their search only the identifiers of the web service description language (WSDL interface elements. The methods based on semantics (WSDLS, OWLS, SAWSDL… which increase the WSDL description of a Web service with a semantic description allow raising partially this problem, but their complexity and difficulty delays their adoption in real cases. Measuring the similarity between the web services interfaces is the most suitable solution for this kind of problems, it will classify available web services so as to know those that best match the searched profile and those that do not match. Thus, the main goal of this work is to study the degree of similarity between any two web services by offering a new method that is more effective than existing works.
Measurement and calculation of the neutron flux distribution in the RP-10 reactor
International Nuclear Information System (INIS)
In this work implementing experimental methods are implemented for easy reproduction for measuring the spatial distribution or thermal neutron flux in the RP-10 reactor core. Using two measuring methods: the passive and the active ones. In the passive method was used the activation technique using foils such as gold, manganese, and indium. These were irradiated in the reactor core and treated through the Westcott's formalism. In the active method was used the Self Powered Neutron Detectors (SPNs) for which was necessary to condition the detectors response for the data acquisition. The knowledge of the spatial distribution of RP-10 reactor neutrons flux will contribute in the understanding of other interesting parameters of reactor physics such as power density, reactivity, buckling, etc.. Wish knowledge is important for reactor operation. Fuel burnup calculations as well as others related to safety. (author)
A calculation method of plant similarity giving consideration to different plant features.
Ding, Wei-long; Wu, Shui-sheng; Max, Nelson; Wu, Fu-li; Xu, Li-feng
2015-12-21
A method to compute the similarity between different plants is proposed, using features of a plant׳s topological structure and peripheral contour, as well as its geometry. The topological structures are described using tree graphs, and their similarity can be calculated based on the edit distance of these graphs. The peripheral contour of a plant is abstracted by its three-dimensional convex hull, which is projected in several directions. The similarity of the different projections is calculated by an algorithm to compute the similarity of two-dimensional shapes. The similarity of the geometrical detail is computed by considering the geometrical properties of different level branches. Finally the overall similarity between different plants is calculated by combining these different similarity measures. The validity of proposed method is evaluated by detailed experiments. PMID:26408336
Method of Images for the Fast Calculation of Temperature Distributions in Packaged VLSI Chips
Hériz, Virginia Martín; Kemper, T; Kang, S -M; Shakouri, A
2008-01-01
Thermal aware routing and placement algorithms are important in industry. Currently, there are reasonably fast Green's function based algorithms that calculate the temperature distribution in a chip made from a stack of different materials. However, the layers are all assumed to have the same size, thus neglecting the important fact that the thermal mounts which are placed underneath the chip can be significantly larger than the chip itself. In an earlier publication, we showed that the image blurring technique can be used to calculate quickly temperature distribution in realistic packages. For this method to be effective, temperature distribution for several point heat sources at the center and at the corner and edges of the chip should be calculated using finite element analysis (FEA) or measured. In addition, more accurate results require correction by a weighting function that will need several FEA simulations. In this paper, we introduce the method of images that take the symmetry of the thermal boundary...
An automated Monte-Carlo based method for the calculation of cascade summing factors
Jackson, M. J.; Britton, R.; Davies, A. V.; McLarty, J. L.; Goodwin, M.
2016-10-01
A versatile method has been developed to calculate cascade summing factors for use in quantitative gamma-spectrometry analysis procedures. The proposed method is based solely on Evaluated Nuclear Structure Data File (ENSDF) nuclear data, an X-ray energy library, and accurate efficiency characterisations for single detector counting geometries. The algorithm, which accounts for γ-γ, γ-X, γ-511 and γ-e- coincidences, can be applied to any design of gamma spectrometer and can be expanded to incorporate any number of nuclides. Efficiency characterisations can be derived from measured or mathematically modelled functions, and can accommodate both point and volumetric source types. The calculated results are shown to be consistent with an industry standard gamma-spectrometry software package. Additional benefits including calculation of cascade summing factors for all gamma and X-ray emissions, not just the major emission lines, are also highlighted.
Estonian oil shale resources calculated by GIS method
International Nuclear Information System (INIS)
A digital map of Estonian oil shale mining was created for joining the data about technological, environmental, and social limitations in the deposit. For evaluating potential resource of oil shale, based on borehole database, its amount, tonnage and energy were calculated. Thereafter the quantity of economical oil shale for power plants and shale oil resource were calculated. Energy rating is the most important factor for determining oil shale reserves in the case of using it for electricity generation. In the case of oil production, data on oil yield and potential resources in oil shale are the most important figures to determine the value of the deposit. Basing on the models, oil resource has been calculated. Resource data can be used for composing master plans for the deposit considering both power generation and oil production. The data can be also used for composing development plans of mines and for logistics calculations. (author)
Comparison of Methods for Calculating Radiative Heat Transfer
Energy Technology Data Exchange (ETDEWEB)
Schock, Alfred; Abbate, M J
2012-01-19
Various approximations for calculating radioactive heat transfer between parallel surfaces are evaluated. This is done by applying the approximations based on total emissivities to a special case of known spectral emissivities, for which exact heat transfer calculations are possible. Comparison of results indicates that the best approximation is obtained by basing the emissivity of the receiving surface primarily on the temperature of the emitter. A specific model is shown to give excellent agreement over a very wide range of values.
An approximate method for calculating the deformation of rotating nuclei
International Nuclear Information System (INIS)
The author presents as a collective model where the potential surface at spin I=0 is calculated in the Nilsson-Strutinsky model, an analytical expression for the moment of inertia is used which depends on the deformation and the pairing gaps for protons and neutrons, and the energy is minimized with respect to these gaps. Calculations in this model are performed for 16Oyb. (HSI)
A mathematical method to calculate efficiency of BF3 detectors
Institute of Scientific and Technical Information of China (English)
SI Fenni; HU Qingyuan; PENG Taiping
2009-01-01
In order to calculate absolute efficiency of the BF3 detector, MCNP/4C code is applied to calculate rela-tive efficiency of the BF3 detector first, and then absolute efficiency is figured out through mathematical techniques. Finally an energy response curve of the BF3 detector for 1~20 MeV neutrons is derived. It turns out that efficiency of BF3 detector are relatively uniform for 2~16 MeV neutrons.
IMAGE PROCESSING METHOD TO MEASURE SUGARCANE LEAF AREA
Directory of Open Access Journals (Sweden)
Sanjay B. Patil
2011-08-01
Full Text Available In order to increase the average sugarcane yield per acres with minimum cost farmers are adapting precision farming technique. This paper includes the area measurement of sugarcane leaf based on image processing method which is useful for plants growth monitoring, to analyze fertilizer deficiency and environmental stress,to measure diseases severity. In image processing method leaf area is calculated through pixel number statistic. Unit pixel in the same digital images represent the same size hence from known reference area and pixel count, unit pixel size can calculate, so that it is easy to calculate leaf area by counting total pixel in leaf area region. The results are compared with the results of graphical area measurement method. The experimentally it is proved that image processing method for measuring sugarcane leaf area is accurate and strong practicabilitywith small relative error.
Calculation of phonon spectrum for noble metals by modified analytic embedded atom method (MAEAM)
Institute of Scientific and Technical Information of China (English)
Zhang Xiao-Jun; Zhang Jian-Min; Xu Ke-Wei
2006-01-01
In the harmonic approximation, the atomic force constants are derived and the phonon dispersion curves along four major symmetry directions [00ζ], [0ζζ], [ζζζ] and [0ζ1] (or △, ∑, A and Z in group-theory notation) are calculated for four noble metals Cu, Ag, Au and Pt by combining the modified analytic embedded atom method (MAEAM) with the theory of lattice dynamics. A good agreement between calculations and measurements, especially for lower frequencies,shows that the MAEAM provides a reasonable description of lattice dynamics in noble metals.
Energy Technology Data Exchange (ETDEWEB)
Rovni, István, E-mail: rovni@reak.bme.hu [Budapest University of Technology and Economics (BME), Institute of Nuclear Techniques, 1111. Budapest, Műegyetem rkp 3-9 (Hungary); Szieberth, Máté [Budapest University of Technology and Economics (BME), Institute of Nuclear Techniques, 1111. Budapest, Műegyetem rkp 3-9 (Hungary); Palcsu, László; Major, Zoltán [Hertelendi Laboratory of Environmental Studies, 4026 Debrecen, Bem tér 18/C (Hungary); Fehér, Sándor [Budapest University of Technology and Economics (BME), Institute of Nuclear Techniques, 1111. Budapest, Műegyetem rkp 3-9 (Hungary)
2013-06-21
This paper presents high accuracy tritium production rate measurement results compared with calculations using the MCNPX Monte Carlo particle transport code. The experimental results are regarded as reference values for a new passive technique based on the secondary charged particle activation method developed for measuring the tritium production rate in the test blanket modules of the ITER Tokamak. The {sup 16}O(t,n){sup 18}F reaction, which is one of the possible tritium monitor reactions, was also extensively investigated, and the experimentally determined reaction rates were compared with simulations. Li{sub 2}CO{sub 3} solution was filled and sealed into quartz ampoules which were irradiated in the Training Reactor of the Budapest University of Technology and Economics. The amount of {sup 18}F was determined using γ-spectroscopy. Then the precise tritium measurements were carried out in the Hertelendi Laboratory of Environmental Studies using the {sup 3}H–{sup 3}He ingrowth method, where the {sup 3}He produced during the storage time is measured by a static noble gas mass spectrometer (VG-5400). The HT/HTO ratio in the irradiated aqueous solutions was found to be 0.1323±0.0034. Based on the comparison of the measurements and the simulations it was pointed out that the model calculations underestimate the reaction rate of both the {sup 6}Li(n,t)α and the {sup 16}O(t,n){sup 18}F reactions by 5–10% and 15%, respectively. -- Highlights: ► Tritium measurements for verifying the {sup 6}Li6(n, t)α reaction rate calculated by MCNPX. ► The HT/HTO ratio was determined in the neutron irradiated aqueous solution of Li{sub 2}CO{sub 3}. ► The reaction rate of {sup 16}O(t,n){sup 18}F was measured in thermal neutron spectrum.
Comparison of Different Methods for Calculating Gyrotron Quasi-Optical Mode Converters
Gashturi, A. P.; Chirkov, A. V.; Denisov, G. G.; Paveliev, A. B.
2013-01-01
This paper presents the use of combination of three methods for calculation and synthesis of high-efficiency microwave mode converters, such as radiators of gyrotrons. The analytical method yields immediate estimates of mode converter dimensions, the Scalar Integral Equation (SIE) allows one to synthesize efficiently the optimal profile of the mode converter, and the most accurate Electric Field Integral Equation (EFIE) is used to check all transmission characteristics of the converter including calculations of reflection and cross-polarization. The combination of these three methods is an optimal for the mode converter design. Just so the launcher was designed for a quasi-optical mode converter used in the 60 GHz gyrotron in the TE7,3 operating mode. The simulation results agree well with the measured data. The paper also presents for the first time an accurate derivation of the SIE method.
Large subcriticality measurement by pulsed neutron method
International Nuclear Information System (INIS)
To establish the method determining large subcriticalities in the field of nuclear criticality safety, the authors performed pulsed neutron experiments using the Kyoto University Critical Assembly (KUCA) at Research Reactor Institute, Kyoto University and the Cockcroft-Walton type accelerator attached to the assembly. The area-ratio method proposed by Sjoestrand was employed to evaluate subcriticalities from neutron decay curves measured. This method has the shortcomings that the neutron component due to a decay of delayed neutrons remarkably decreases as the subcriticality of an objective increases. To overcome the shortcoming, the authors increased the frequency of pulsed neutron generation. The integral-version of the area-ratio method proposed by Kosaly and Fisher was employed in addition in order to remove a contamination of spatial higher modes from the decay curve. The latter becomes significant as subcriticality increases. The largest subcriticality determined in the present experiments was 125.4 dollars, which was equal to 0.5111 in a multiplication factor. The calculational values evaluated by the computer code KENO-IV with 137 energy groups based on the Monte Carlo method agreed well with those experimental values
Study on peak shape fitting method in radon progeny measurement.
Yang, Jinmin; Zhang, Lei; Abdumomin, Kadir; Tang, Yushi; Guo, Qiuju
2015-11-01
Alpha spectrum measurement is one of the most important methods to measure radon progeny concentration in environment. However, the accuracy of this method is affected by the peak tailing due to the energy losses of alpha particles. This article presents a peak shape fitting method that can overcome the peak tailing problem in most situations. On a typical measured alpha spectrum curve, consecutive peaks overlap even their energies are not close to each other, and it is difficult to calculate the exact count of each peak. The peak shape fitting method uses combination of Gaussian and exponential functions, which can depict features of those peaks, to fit the measured curve. It can provide net counts of each peak explicitly, which was used in the Kerr method of calculation procedure for radon progeny concentration measurement. The results show that the fitting curve fits well with the measured curve, and the influence of the peak tailing is reduced. The method was further validated by the agreement between radon equilibrium equivalent concentration based on this method and the measured values of some commercial radon monitors, such as EQF3220 and WLx. In addition, this method improves the accuracy of individual radon progeny concentration measurement. Especially for the (218)Po peak, after eliminating the peak tailing influence, the calculated result of (218)Po concentration has been reduced by 21 %. PMID:25920795
Methods for High Power EM Pulse Measurement
Fiala, P.; Drexler, P.
2006-01-01
There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday...
Institute of Scientific and Technical Information of China (English)
Hong Tang; Xiaogang Sun; Guibin Yuan
2007-01-01
In total light scattering particle sizing technique, the relationship among Sauter mean diameter D32, mean extinction efficiency Q, and particle size distribution function is studied in order to inverse the mean diameter and particle size distribution simply. We propose a method which utilizes the mean extinction efficiency ratio at only two selected wavelengths to solve D32 and then to inverse the particle size distribution associated with (Q) and D32. Numerical simulation results show that the particle size distribution is inversed accurately with this method, and the number of wavelengths used is reduced to the greatest extent in the measurement range. The calculation method has the advantages of simplicity and rapidness.
Pion-Induced Fission of 209Bi and 119Sn:. Measurements, Calculations, Analyses and Comparison
Rana, Mukhtar Ahmed; Sher, Gul; Manzoor, Shahid; Shehzad, M. I.
Cross-sections for the π--induced fission of 209Bi and 119Sn have been measured using the most sensitive CR-39 solid-state nuclear track detector. In experiments, target-detector stacks were exposed to negative pions of energy 500, 672, 1068, and 1665 MeV at the Brookhaven National Laboratory, USA. An important aspect of the present paper is the comparison of pion-induced fission fragment spectra of above mentioned nuclei with the spontaneous fission fragment spectra of 252Cf. This comparison is made in terms of fission fragment track lengths in the CR-39 detectors. Measurement results are compared with calculations of Monte Carlo and statistical weight functions methods using the computer code CEM95. Agreement between measurements and calculations is fairly good for 209Bi target nuclei whereas it is indigent for the case of 119Sn. The possibilities of the trustworthy calculations, using the computer code CEM95, comparable with measurements of pion-induced fission in intermediate and heavy nuclei are explored by employing various systematics available in the code. Energy dependence of pion-induced fission in 119Sn and 209Bi is analyzed employing a newly defined parameter geometric-size-normalized fission cross-section (χfg). It is found that the collective nuclear excitations, which may lead to fission, become more probable for both 209Bi and 119Sn nuclei with increasing energy of negative pions from 500 to 1665 MeV.
Calculation of VPP basing on functional analyzing method
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
VPP can be used to deter mine the maxi mumvelocities of a sailboard at various sailing-routes,byestablishing the forces and moments balance-equa-tions on the sail and board in accordance with theprinciple of the maxi mal drive-force.Selectingroute is the most i mportant issue in upwind-sailing,and VPP calculations could provide the basis for de-ter mining the opti mal routes.VPP calculation of the sailboard perfor mance isa complex and difficult research task,and there arefew projects in this research-field...
Dynamic Inertia Measurement Method Project
National Aeronautics and Space Administration — Critically important inertia measurements are complex and expensive to obtain due to the extensive fixturing and custom instrumentation of conventional...
Comparison of hardenability calculation methods of the heat-treatable constructional steels
International Nuclear Information System (INIS)
Evaluation has been made of the consistency of calculation of the hardenability curves of the selected heat-treatable alloyed constructional steels with the experimental data. The study has been conducted basing on the analysis of present state of knowledge on hardenability calculation employing the neural network methods. Several calculation examples and comparison of the consistency of calculation methods employed are included. (author)
Open Photoacoustic Cell for Blood Sugar Measurement: Numerical Calculation of Frequency Response
Baumann, Bernd; Teschner, Mark
2015-01-01
A new approach for continuous and non-invasive monitoring of the glucose concentration in human epidermis has been suggested recently. This method is based on photoacoustic (PA) analysis of human interstitial fluid. The measurement can be performed in vitro and in vivo and, therefore, may form the basis for a non-invasive monitoring of the blood sugar level for diabetes patients. It requires a windowless PA cell with an additional opening that is pressed onto the human skin. Since signals are weak, advantage is taken of acoustic resonances of the cell. Recently, a numerical approach based on the Finite Element (FE) Method has been successfully used for the calculation of the frequency response function of closed PA cells. This method has now been adapted to obtain the frequency response of the open cell. Despite the fact that loss due to sound radiation at the opening is not included, fairly good accordance with measurement is achieved.
A density gradient theory based method for surface tension calculations
DEFF Research Database (Denmark)
Liang, Xiaodong; Michelsen, Michael Locht; Kontogeorgis, Georgios
2016-01-01
The density gradient theory has been becoming a widely used framework for calculating surface tension, within which the same equation of state is used for the interface and bulk phases, because it is a theoretically sound, consistent and computationally affordable approach. Based on the observati...
Pose measurement method based on geometrical constraints
Institute of Scientific and Technical Information of China (English)
Zimiao Zhang; Changku Sun; Pengfei Sun; Peng Wang
2011-01-01
@@ The pose estimation method based on geometric constraints is studied.The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane; during the solution process,the scaling and orthography projection model is used to approximate the perspective projection model.%The pose estimation method based on geometric constraints is studied. The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane; during the solution process, the scaling and orthography projection model is used to approximate the perspective projection model. The initial values of the coordinates of the five feature points in the camera coordinate system are obtained to ensure the accuracy and convergence rate of the non-linear algorithm. In accordance with the perspective projection characteristics of the circular feature landmarks, we propose an approach that enables the iterative acquisition of accurate target poses through the correction of the perspective projection coordinates of the circular feature landmark centers. Experimental results show that the translation positioning accuracy reaches ±0.05 mm in the measurement range of 0-40 mm, and the rotation positioning accuracy reaches ±0.06° in the measurement range of 4°-60°.
A new configuration selection method for configuration interaction calculations
Visscher, L.; Raedt, H. De; Nieuwpoort, W.C.
1994-01-01
The recently proposed stochastic diagonalization method is applied to the ab initio quantum chemistry configuration interaction problem. In this context it can be viewed as a multi-reference CI method with dynamic selection of important configurations. The method is compared with other methods and t
WAVELET METHOD FOR CALCULATING THE DEFECT STATES OF TWO-DIMENSIONAL PHONONIC CRYSTALS
Institute of Scientific and Technical Information of China (English)
Zhizhong Yan; Yuesheng Wang; Chuanzeng Zhang
2008-01-01
Based on the variational theory, a wavelet-based numerical method is developed to calculate the defect states of acoustic waves in two-dimensional phononic crystals with point and line defects. The supercell technique is applied. By expanding the displacement field and the material constants (mass density and elastic stiffness) in periodic wavelets, the explicit formulations of an eigenvalue problem for the plane harmonic bulk waves in such a phononic structure are derived. The point and line defect states in solid-liquid and solid-solid systems are calculated. Comparisons of the present results with those measured experimentally or those from the plane wave expansion method show that the present method can yield accurate results with faster convergence and less computing time.
International Nuclear Information System (INIS)
The tip deflections of wind turbine blades should be monitored continuously to prevent catastrophic failures of wind turbine power plants caused by blades hitting the tower. In this paper, a calculation method for wind turbine blade tip deflection is proposed using a finite difference method based on arbitrary beam bending and moment theory using measured strains. The blade strains were measured using fiber optic Bragg grating sensors. In order to confirm this method, a 100 kW composite wind turbine blade was manufactured with epoxy molded fiber optic Bragg grating (FBG) sensors installed in the shear web of the blade. A number of these sensors, normal FBG probes, were fabricated to only measure strains and the other sensors, temperature compensated FBG probes, were prepared to also measure strain and temperature. Because the output signals of FBG sensors are dependent on strains as well as temperatures, the sensor output signals should be compensated by the temperatures to obtain accurate strains. These FBG sensors were attached on the lower and upper parts of the web at one meter intervals throughout the entire length of the blade. To evaluate the measurement accuracy of the FBG sensors, conventional electrical strain gauges were also bonded onto the surface of the web beside each FBG sensor. By performing a static load test of the blade, the calculated tip deflection of the blade was well determined within an average error of 2.25%. (paper)
International Nuclear Information System (INIS)
The measurement of cerebral blood flow (CBF) by the extracranial detection of the radioactivity of 133Xe injected into an internal carotid artery has proved to be of considerable value for the investigation of cerebral circulation in conscious rabbits. Methods are described for calculating CBF from the curves of clearance of 133Xe, and include exponential analysis (two-component model), initial slope, and stochastic method. The different methods of curve analysis were compared in order to evaluate the fitness with the theoretical model. The initial slope and stochastic methods, compared with the biexponential model, underestimate the CBF by 35% and 46% respectively. Furthermore, the validity of recording the clearance curve for 10 min was tested by comparing these CBF values with those obtained from the whole curve. CBF values calculated with the shortened procedure are overestimated by 17%. A correlation exists between the ''10 min'' CBF values and the CBF calculated from the whole curve; in spite of that, the values are not accurate for limited animal populations or for single animals. The extent of the two main compartments into which the CBF is divided was also measured. There is no correlation between CBF values and the extent of the relative compartment. This fact suggests that these two parameters correspond to different biological entities
Calculations of NMR chemical shifts with APW-based methods
Laskowski, Robert; Blaha, Peter
2012-01-01
We present a full potential, all electron augmented plane wave (APW) implementation of first-principles calculations of NMR chemical shifts. In order to obtain the induced current we follow a perturbation approach [Pickard and Mauri, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.63.245101 63, 245101 (2001)] and extended the common APW + local orbital (LO) basis by several LOs at higher energies. The calculated all-electron current is represented in traditional APW manner as Fourier series in the interstitial region and with a spherical harmonics representation inside the nonoverlapping atomic spheres. The current is integrated using a “pseudocharge” technique. The implementation is validated by comparison of the computed chemical shifts with some “exact” results for spherical atoms and for a set of solids and molecules with available published data.
Energy Technology Data Exchange (ETDEWEB)
NONE
2002-05-01
The CRE began the 22 october 2001 a public opinion on the avoided costs calculation methods, to determine the charges amount of the electric utilities. The main questions dealt with the general position of the actors towards the two calculation methods proposed by the CRE; the modalities of these methods implementing; the alternative and possible methods; the case of the non national distributors. The answers are detailed and analyzed. (A.L.B.)
Automated Methods of Corrosion Measurements
DEFF Research Database (Denmark)
Andersen, Jens Enevold Thaulov
1997-01-01
electrochemical measurements as well as elemental analysis look very promising for elucidating corrosion reaction mechanisms. The study of initial surface reactions at the atomic or submicron level is becoming an important field of research in the understanding of corrosion processes. At present, mainly two...... scanning microscope techniques are employed investigating corrosion processes, and usually in situ: in situ scanning tunneling microscopy (in situ STM) and in situ scanning force microscopy (in situ AFM). It is these techniques to which attention is directed here....
Calculation of power network reliability - a comparison of methods
Energy Technology Data Exchange (ETDEWEB)
Niehage, U.
1987-11-01
The execution of reliability analyses is one of the major working steps in the planning of network extension with so-called heuristic or deterministic methods being preferred. These methods have proved their value and are recognized both nationally and internationally. Along with these methods, probabilistic methods for the analysis of network reliability have been known from literature for some 20 years. Such methods have been developed and continuously upgraded in the German-speaking countries espec. for the examination of 110 kV networks till today.
Institute of Scientific and Technical Information of China (English)
赵晓刚
2012-01-01
Combined with production practice, calculating methods of mixed oil quantity in the batch transportation product pipeline were mainly introduced as well as theoretical formula, corrected theoretical formula and empirical formula. Through example calculation, different formulae were compared. Then, factors to influence mixed oil quantity were analyzed, and measures to reduce mixed oil quantity were put forward.%结合生产实际,重点介绍了成品油顺序输送管道混油量的计算方法,包括理论公式、修正的理论公式以及经验公式,并进行了相应的实例计算,对各种计算公式进行的比较,分析了混油量的影响因素,提出了减少混油量的措施.
Directory of Open Access Journals (Sweden)
A. Yu. Zhuravlev
2016-04-01
network coefficients. When building the FM reversal model in parallel magnetic fields, the most accurate methods are the approximation ones that take into account not only the changes in values and over time, but also their derivatives. The development of computer hardware and software makes real the mathematical methods for calculating TC with significant change in ferromagnetic inductance, including the saturation areas. Herewith, it is important to search for approximating analytical expression that describes the dynamic limit hysteresis loop (HL. Practical value. The changes in the electrical parameters of the same TC were analysed using the classical and the new calculation methods, the difference made less than 10%. The work introduced some measures to increase operational noise immunity of TC.
Flow measurement by ultrasonic method
International Nuclear Information System (INIS)
An Ultrasonic Flow Meter (USFM) wasdeveloped to measure flow velocity of high temperature fluid in a pipe. To protect ultrasonic transducers from high temperature, guide rods were used. From the study on mechanical structure and acoustic property, the guide rod and the electronic circuit were improved to have capabilities of temperature compensation, quick response, high accuracy and not to be easily disturbed by bubbles contained in the fluid flow. Using a water flow loop, the test results proved the accuracy of +-1.0 percent and response time of 10 m sec
Pennec, Fabienne; Alzina, Arnaud; Tessier-Doyen, Nicolas; Naitali, Benoit; Smith, David S.
2012-11-01
This work is about the calculation of thermal conductivity of insulating building materials made from plant particles. To determine the type of raw materials, the particle sizes or the volume fractions of plant and binder, a tool dedicated to calculate the thermal conductivity of heterogeneous materials has been developped, using the discrete element method to generate the volume element and the finite element method to calculate the homogenized properties. A 3D optical scanner has been used to capture plant particle shapes and convert them into a cluster of discret elements. These aggregates are initially randomly distributed but without any overlap, and then fall down in a container due to the gravity force and collide with neighbour particles according to a velocity Verlet algorithm. Once the RVE is built, the geometry is exported in the open-source Salome-Meca platform to be meshed. The calculation of the effective thermal conductivity of the heterogeneous volume is then performed using a homogenization technique, based on an energy method. To validate the numerical tool, thermal conductivity measurements have been performed on sunflower pith aggregates and on packed beds of the same particles. The experimental values have been compared satisfactorily with a batch of numerical simulations.
International Nuclear Information System (INIS)
This work is about the calculation of thermal conductivity of insulating building materials made from plant particles. To determine the type of raw materials, the particle sizes or the volume fractions of plant and binder, a tool dedicated to calculate the thermal conductivity of heterogeneous materials has been developped, using the discrete element method to generate the volume element and the finite element method to calculate the homogenized properties. A 3D optical scanner has been used to capture plant particle shapes and convert them into a cluster of discret elements. These aggregates are initially randomly distributed but without any overlap, and then fall down in a container due to the gravity force and collide with neighbour particles according to a velocity Verlet algorithm. Once the RVE is built, the geometry is exported in the open-source Salome-Meca platform to be meshed. The calculation of the effective thermal conductivity of the heterogeneous volume is then performed using a homogenization technique, based on an energy method. To validate the numerical tool, thermal conductivity measurements have been performed on sunflower pith aggregates and on packed beds of the same particles. The experimental values have been compared satisfactorily with a batch of numerical simulations.
Cost Accounting Methods and Calculation Agricultural Products` Cost
Directory of Open Access Journals (Sweden)
Saule B. Spatayeva
2015-04-01
Full Text Available In the condition of the current market the effective manage of expenses and calculation accountancy of cost production in agriculture must be aimed to control for resources usage at any level of technology process and getting the accountancy database needed for gaining the management targets.The improving the technologies and set up aspects of business entity activity, taken place for the last decades, which caused a significant influence on condition and structure expenses but could not provide the increase of economic effectiveness in agriculture.
Single-Sweep Methods for Free Energy Calculations
Maragliano, Luca; Vanden-Eijnden, Eric
2007-01-01
A simple, efficient, and accurate method is proposed to map multi-dimensional free energy landscapes. The method combines the temperature-accelerated molecular dynamics (TAMD) proposed in [Maragliano & Vanden-Eijnden, Chem. Phys. Lett. 426, 168 (2006)] with a variational reconstruction method using radial-basis functions for the representation of the free energy. TAMD is used to rapidly sweep through the important regions of the free energy landscape and compute the gradient of the free energ...
Calculating and measuring thermal neutrons exiting from neutron diffractometers collimators
Tafazolee, K
2000-01-01
process, effectiveness of them are studied for the enhancement of the available system. Final conclusion from the simulation process, indicates that the heavy water with the thickness of 50 to 60 cm. is the best moderator for gaining the better thermal neutrons flux for enhancement of P.N.D. in the T.R.R. Powder Neutron Diffractometer y (P.N.D.) is relatively good and practical way for identification of the 3 dimensional construction of materials. In order to exploit the capabilities of this method, in one of the neutron beam of the Tehran Research Reactor (T.R.R.), a collimator embedded inside the concrete wall, direct the neutrons produced in the core reactor towards a monochromator e. Neutrons having been monochromated by 2 nd collimator are then directed towards the sample. Then the pattern of diffracted neutrons from the sample are studied. In order to make the best out of it, neutrons coming to sit on the sample must be of the thermal type. That means the number/amount of thermal neutrons flux in compar...
Measurement and calculation of radon releases from uranium mill tailings
International Nuclear Information System (INIS)
The mining and milling of uranium ores produces large quantities of radioactive wastes. Although relatively small in magnitude compared to tailings from metal mining and extraction processes, the present worldwide production of such tailings exceeds 20 million tonnes annually. There is thus a need to ensure that the environmental and health risks from these materials are reduced to an acceptable level. This report has been written as a complement to another publication entitled Current Practices for the Management and Confinement of Uranium Mill Tailings, IAEA Technical Reports Series No. 335, which provides a general overview of all the important factors in the siting, design and construction of tailings impoundments, and in the overall management of tailings with due consideration give to questions of the release of pollutants from tailings piles. The present report provides a comprehensive overview of the release, control and monitoring of radon, including computational methods. The report was first drafted in 1989 and was then reviewed at an Advisory Group meeting in 1990. 42 refs, 9 figs, 3 tabs
Directory of Open Access Journals (Sweden)
Safarini Osama
2012-01-01
Full Text Available An important task of operational management in oil and gas production is the control of fluid flow and technological objects of engineering network (EN. This paper proposed a method for diagnosis of fluid flow measurement and calibration operations. The method is based on the relationship between various parameters of the flow of Engineering Network. To calculate the actual flow rate on other parameters of the flow, such as pressure, temperature, and the parameters that determine the composition of the liquid (oil, it is proposed to use a neural network.
Volume calculation of the spur gear billet for cold precision forging with average circle method
Institute of Scientific and Technical Information of China (English)
Wangjun Cheng; Chengzhong Chi; Yongzhen Wang; Peng Lin; Wei Liang; Chen Li
2014-01-01
Forging spur gears are widely used in the driving system of mining machinery and equipment due to their higher strength and dimensional accuracy. For the purpose of precisely calculating the volume of cylindrical spur gear billet in cold precision forging, a new theoretical method named average circle method was put forward. With this method, a series of gear billet volumes were calculated. Comparing with the accurate three-dimensional modeling method, the accuracy of average circle method by theoretical calculation was estimated and the maximum relative error of average circle method was less than 1.5%, which was in good agreement with the experimental results. Relative errors of the calculated and the experimental for obtaining the gear billet volumes with reference circle method are larger than those of the average circle method. It shows that average circle method possesses a higher calculation accuracy than reference circle method (traditional method), which should be worth popularizing widely in calculation of spur gear billet volume.
Verification and Calculation of Negative Refractive Indices of a Meta-Material by Numerical Method
Institute of Scientific and Technical Information of China (English)
SUI Qiang; LIU Ci-Xiang; LI Chao; LI Fang
2005-01-01
@@ The verification and calculation of the negative refractive index of a meta-material is carried out by the finite difference time-domain method. A slab and a prism of the meta-material are simulated. A genuine plane wave is generated by a two-direction periodic boundary condition (PBC) in the slab model Based on an advanced phase extraction technique, the negative refractive index of the meta-material is verified by phase velocity measurement in the slab and prism measurement. From our results, not only the phenomenon of backward phase propagation but also the negative refraction is clearly observed. The index is also calculated precisely. The results from the two models are consistent.
Energy Technology Data Exchange (ETDEWEB)
Zagar, T.; Ravnik, M.; Persic, A. (J.Stefan Institute, Ljubljana (Slovenia))
1999-12-15
Results of fuel element burn-up determination by measurement and calculation are given. Fuel element burn-up was calculated with two different programs TRIGLAV and TRIGAC using different models. New TRIGLAV code is based on cylindrical, two-dimensional geometry with four group diffusion approximation. TRIGAC program uses one-dimensional cylindrical geometry with twogroup diffusion approximation. Fuel element burn-up was measured with reactivity method. In this paper comparison and analysis of these three methods is presented. Results calculated with TRIGLAV show considerably better alignment with measured values than results calculated with TRIGAC. Some two-dimensional effects in fuel element burn-up can be observed, for instance smaller standard fuel element burn-up in mixed core rings and control rod influence on nearby fuel elements. (orig.)
Method for measuring anterior chamber volume by image analysis
Zhai, Gaoshou; Zhang, Junhong; Wang, Ruichang; Wang, Bingsong; Wang, Ningli
2007-12-01
Anterior chamber volume (ACV) is very important for an oculist to make rational pathological diagnosis as to patients who have some optic diseases such as glaucoma and etc., yet it is always difficult to be measured accurately. In this paper, a method is devised to measure anterior chamber volumes based on JPEG-formatted image files that have been transformed from medical images using the anterior-chamber optical coherence tomographer (AC-OCT) and corresponding image-processing software. The corresponding algorithms for image analysis and ACV calculation are implemented in VC++ and a series of anterior chamber images of typical patients are analyzed, while anterior chamber volumes are calculated and are verified that they are in accord with clinical observation. It shows that the measurement method is effective and feasible and it has potential to improve accuracy of ACV calculation. Meanwhile, some measures should be taken to simplify the handcraft preprocess working as to images.
Projection methods for the calculation of incompressible or dilatable flows
International Nuclear Information System (INIS)
This thesis treats of time resolution methods for the Navier-Stokes equations. Based on the well-known projection method of Chorin and Temam, an original pressure correction method, named 'projection-penalty' is developed. Its specificity concerns the addition of a penalty term in the prediction step, which constrains the predicted velocity to fit with the mass balance. The precision improvements added by this method are demonstrated by some analysis results and by some numerical experiments of incompressible or dilatable flows. Finally, the potentialities offered by the use of the joint finite elements method in this type of fractionary step scheme is studied. Two applications are presented, one for local refinement purpose, the other for the resolution of a multi-physics problem. (J.S.)
Nuclear data production, calculation and measurement: a global overview of the gamma heating issue
Directory of Open Access Journals (Sweden)
Gueton O.
2013-03-01
Full Text Available The gamma heating evaluation in different materials found in current and future generations of nuclear reactor (EPRTM, GENIV, MTR-JHR, is becoming an important issue especially for the design of many devices (control rod, heavy reflector, in-core & out-core experiments…. This paper deals with the works started since 2009 in the Reactor Studies Department of CEA Cadarache in ordre to answer to several problematic which have been identified as well for nuclear data production and calculation as for experimental measurement methods. The selected subjects are: Development of a Monte Carlo code (FIFRELIN to simulate the prompt fission gamma emission which represents the major part of the gamma heating production inside the core Production and qualification of new evaluations of nuclear data especially for radiative capture and inelastic neutron scattering which are the main sources of gamma heating out-core Development and qualification of a recommended method for the total gamma heating calculation using the Monte Carlo simulation code TRIPOLI-4 Development, test and qualification of new devices dedicated to the in-core gamma heating measurement as well in MTR-JHR as in zero power facilities (EOLE-MINERVE of CEA, Cadarache to increase the experimental measurement accuracy.
Measurement and Calculation of Frictional Loss in Large Two-Stroke Engines
DEFF Research Database (Denmark)
Vølund, Anders
2003-01-01
The total frictional loss in a large two-stroke marine diesel engine is rather well determined. However, the contribution (size and distribution) from the different machine elements are not well known. The aim of this study is to establish methods to measure and calculate friction in the piston......%. The rest of the mechanical loss is situated in the piston rod 2%, piston skirt 3% and main bearings and connecting rod bearing 12%. Information about the friction distribution can be used in future design of these machine elements. Theoretical models for determination of frictional losses for both...
Measurement and Calculation of Frictional Loss in Large Two-Stroke Engines
Vølund, Anders; Klit, Peder
2003-01-01
The total frictional loss in a large two-stroke marine diesel engine is rather well determined. However, the contribution (size and distribution) from the different machine elements are not well known. The aim of this study is to establish methods to measure and calculate friction in the piston assembly and guide shoe system for a large two-stroke marine diesel engine. These components are the two major contributors to the total friction in a two-stroke marine diesel engine. The piston pack r...
CALCULATION OF HELICOPTER ROTOR FLAPPING ANGLES AND COMPARISON WITH MEASURED DATA
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Helicopter rotor flapping angles from hover to low-speed forward flight are calculated and compared with the measured data in this paper. The analytical method is based on a second order lifting-line/full-span free wake model as well as a fully coupled rotor trim model. It is shown that, in order to accurately predict the lateral flapping angle at low advance ratio, it is necessary to use free wake analysis to account for the highly non-uniform inflow induced by the distorted wake geometry at rotor disc plane.
A row-by-row off-design performance calculation method for turbines
Schobeiri, T.; Abouelkheir, M.
1991-01-01
The turbine component of a gas turbine engine is frequently subjected to extreme operation conditions associated with significant changes in mass flow, turbine inlet temperature, pressure and rotational speed. These off-design operation conditions significantly affect the flow deflection within the turbine stage, which consists of individual stator and rotor rows. As a result, the stage parameters representing the velocity diagram will change and affect the efficiency and performance of the stage and, thus, the turbine. A row-by-row calculation method is presented for predicting the performance behavior of turbines under extreme off-design conditions. The method is applied to a multistage turbine for which the off-design performance is calculated and compared with the measurement.
A New Pseudospectral Method for Calculations of Hydrogen Atom in Arbitrary External Fields
Institute of Scientific and Technical Information of China (English)
QIAO Hao-Xue; LI Bai-Wen1
2002-01-01
A new pseudospectral method was introduced to calculate wavefunctions and energy levels of hydrogen atom in arbitrary potential. Some results of hydrogen atom in uniform magnetic fields were presented, high accuracy of results was obtained with simple calculations, and our calculations show very fast convergence. It suggests a new methodfor calculations of hydrogen atom in external fields.
A nonlinear analytic function expansion nodal method for transient calculations
Energy Technology Data Exchange (ETDEWEB)
Joo, Han Gyn; Park, Sang Yoon; Cho, Byung Oh; Zee, Sung Quun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1998-12-31
The nonlinear analytic function expansion nodal (AFEN) method is applied to the solution of the time-dependent neutron diffusion equation. Since the AFEN method requires both the particular solution and the homogeneous solution to the transient fixed source problem, the derivation of the solution method is focused on finding the particular solution efficiently. To avoid complicated particular solutions, the source distribution is approximated by quadratic polynomials and the transient source is constructed such that the error due to the quadratic approximation is minimized, In addition, this paper presents a new two-node solution scheme that is derived by imposing the constraint of current continuity at the interface corner points. The method is verified through a series of application to the NEACRP PWR rod ejection benchmark problems. 6 refs., 2 figs., 1 tab. (Author)
Godunov Method for Calculating Multicomponent Heterogeneous Medium Flows
Surov, V. S.
2014-03-01
The modified Godunov method intended for integrating the nondivergent systems that describe a multivelocity heterogeneous mixture flow is presented. The linearized Riemann solver has been used in solving the Riemann problems.
Hourly Calculation Method of Air Source Heat Pump Behavior
Ludovico Danza; Lorenzo Belussi; Italo Meroni; Michele Mililli; Francesco Salamone
2016-01-01
The paper describes an hourly simplified model for the evaluation of the energy performance of heat pumps in cooling mode maintaining a high accuracy and low computational cost. This approach differs from the methods used for the assessment of the overall energy consumption of the building, normally placed in the so-called white or black box models, where the transient conduction equation is deterministically and stochastically solved, respectively. The present method wants to be the expressi...
Development of a software package for solid-angle calculations using the Monte Carlo method
Zhang, Jie; Chen, Xiulian; Zhang, Changsheng; Li, Gang; Xu, Jiayun; Sun, Guangai
2014-02-01
Solid-angle calculations play an important role in the absolute calibration of radioactivity measurement systems and in the determination of the activity of radioactive sources, which are often complicated. In the present paper, a software package is developed to provide a convenient tool for solid-angle calculations in nuclear physics. The proposed software calculates solid angles using the Monte Carlo method, in which a new type of variance reduction technique was integrated. The package, developed under the environment of Microsoft Foundation Classes (MFC) in Microsoft Visual C++, has a graphical user interface, in which, the visualization function is integrated in conjunction with OpenGL. One advantage of the proposed software package is that it can calculate the solid angle subtended by a detector with different geometric shapes (e.g., cylinder, square prism, regular triangular prism or regular hexagonal prism) to a point, circular or cylindrical source without any difficulty. The results obtained from the proposed software package were compared with those obtained from previous studies and calculated using Geant4. It shows that the proposed software package can produce accurate solid-angle values with a greater computation speed than Geant4.
Institute of Scientific and Technical Information of China (English)
LUO Hong-E; TIAN Xiao-Jian; GAO Bo; LI Liang; WU Ge; CAO Liang
2007-01-01
@@ We suggest a novel method to calculate the initial phase difference between two fibre arms of a laser homodyne interferometer. Put the two fibre arms in a temperature controller, whose short term stability is 0.02 ℃ (measured in an hour), then measure the interference photocurrent and the photocurrents from the two fibre arms at a fixed temperature. With these three photocurrents we can calculate the value of the initial phase difference.
Score Calculation in Informatics Contests Using Multiple Criteria Decision Methods
Skupiene, Jurate
2011-01-01
The Lithuanian Informatics Olympiad is a problem solving contest for high school students. The work of each contestant is evaluated in terms of several criteria, where each criterion is measured according to its own scale (but the same scale for each contestant). Several jury members are involved in the evaluation. This paper analyses the problem…
Transmission line icing measurement on photogrammetry method
Huang, Huan; Ma, Xiaohong; Zhao, Lijin; Du, Hao; Luo, Hong; Mao, Xianyin; Tang, Min; Liu, Yawen
2015-12-01
Icing thickness parameter is the basic data for power sector to make decision for icing accident prevention. In this paper, a transmission line icing measurement method is proposed. It used the photogrammetry method to realize icing parameters measurement through the integration of high resolution camera, laser range finder and inertial measurement unit. Compared with traditional icing measurement method, this method is flexible and is the effective supplement of the fixed icing detection terminal. And its high accuracy measurement guarantees the reliability of the icing thickness parameters.
WAKE GEOMETRY CALCULATIONS FOR TILT-ROTOR USING VISCOUS VORTEX METHOD
Institute of Scientific and Technical Information of China (English)
魏鹏; 史勇杰; 徐国华
2013-01-01
A tilt-rotor unsteady flow analytical method has been developed based upon viscous vortex-particle meth-od .In this method ,the vorticity field is divided into small assembled vortex particles .Vortex motion and diffusion are obtained by solving the velocity-vorticity-formed incompressible Navier-Stokes equations using a grid-free La-grangian simulation method .Generation of the newly vortex particles is calculated by using the Weissinger-L lifting surface model .Furthermore ,in order to significantly improve computational efficiency ,a fast multiple method (FMM) is introduced into the calculation of induced velocity and its gradient .Finally ,the joint vertical experimen-tal (JVX) tilt-rotor is taken as numerical examples to analyze .The wake geometry and downwash are investigated for both hover and airplane modes .The proposed method for tilt-rotor flow analysis is verified by comparing its re-sults with those available measured data .Comparison indicates that the current method can accurately capture the complicated tilt-rotor wake variation and be suitable for aerodynamic interaction simulation in complex environ-ments .Additionally ,the aerodynamic interactional characteristics of dual-rotor wake are discussed in different ro-tor distance .Results show that there are significant differences on interactional characteristics between hover mode and airplane mode .
Comparison of measured and calculated temperatures for a Mach 8 hypersonic wing test structure
Quinn, R. D.; Fields, R. A.
1986-01-01
Structural temperatures were measured on a hypersonic wing test structure during a heating test that simulated a Mach 8 thermal environment. Measured data are compared to design calculations and temperature predictions obtained from a finite-difference thermal analysis.
Methods for High Power EM Pulse Measurement
Directory of Open Access Journals (Sweden)
P. Fiala
2006-12-01
Full Text Available There are some suitable methods for the measurement of ultra-short solitary electromagnetic pulses that can be generated by high power pulsed generators. The measurement methods properties have to correspond to the fact whether we want to measure pulses of voltage, current or free-space electromagnetic wave. The need for specific measurement methods occurred by the development of high power microwave pulse generator. Applicable methods are presented in this paper. The method utilizing Faraday's induction law allows the measurement of generated current. For the same purpose the magneto-optic method can be utilized, with its advantages. For measurement of output microwave pulse of the generator the calorimetric method was designed and realized.
Comparison of methods for numerical calculation of continuum damping
Bowden, George; Hole, Matthew; Gorelenkov, Nikolai; Dennis, Graham
2014-01-01
Continuum resonance damping is an important factor in determining the stability of certain global modes in fusion plasmas. A number of analytic and numerical approaches have been developed to compute this damping, particularly in the case of the toroidicity-induced shear Alfv\\'en eigenmode. This paper compares results obtained using an analytical perturbative approach with those found using resistive and complex contour numerical approaches. It is found that the perturbative method does not provide accurate agreement with reliable numerical methods for the range of parameters examined. This discrepancy exists even in the limit where damping approaches zero. When the perturbative technique is implemented using a standard finite element method, the damping estimate fails to converge with radial grid resolution. The finite elements used cannot accurately represent the eigenmode in the region of the continuum resonance, regardless of the number of radial grid points used.
A probabilistic method of calculating circulation-induced trends
Brox Nilsen, Irene; Stagge, James Howard; Merete Tallaksen, Lena
2015-04-01
The water cycle in Europe has changed substantially over the past three decades. Increasing runoff is observed during winter and at northern latitudes in particular. Spring and summer months, as well as southern latitudes, are facing drier conditions. To understand what is driving large-scale changes in runoff, we look into changes in precipitation and temperature and link these to changes in atmospheric circulation. Previous studies have used the method of trend ratios (Cahynová and Huth, 2009) to attribute precipitation and temperature trends to changes in the frequency of circulation types. A trend ratio is the ratio of hypothetical trend, i.e., the trend that would result due to changes in circulation type frequency only, to the observed trend. However, the method of trend ratios has two drawbacks. First, if the observed trend is small, division by a very low value results in a meaningless trend ratio and thus requires a cut-off value to keep the trend ratio within meaningful boundaries. Second, the method does not allow a comparison of the observed trend to the spread of possible outcomes, because the method of hypothetical trends is based on a deterministic model. We propose a new, more robust method for detecting the importance of circulation-induced changes in explaining the observed trends, which has the benefit of being a non-parametric statistical test that assesses the entire range of hypothetical trends. Instead of creating a hypothetical series by replacing the observation on a given day with the long-term climatic mean of a certain month and circulation type (as in the existing trend ratio method), the new approach replaces the observation on a given day with a random sample from the distribution of the variable for the given month and circulation type. The method introduces the possibility to assign a rejection rate, thus allowing statistical significance to be assessed. We apply the method on time series of precipitation and temperature from the
Pisaturo, O; Pachoud, M; Bochud, F O; Moeckli, R
2012-07-21
The quantity of interest for high-energy photon beam therapy recommended by most dosimetric protocols is the absorbed dose to water. Thus, ionization chambers are calibrated in absorbed dose to water, which is the same quantity as what is calculated by most treatment planning systems (TPS). However, when measurements are performed in a low-density medium, the presence of the ionization chamber generates a perturbation at the level of the secondary particle range. Therefore, the measured quantity is close to the absorbed dose to a volume of water equivalent to the chamber volume. This quantity is not equivalent to the dose calculated by a TPS, which is the absorbed dose to an infinitesimally small volume of water. This phenomenon can lead to an overestimation of the absorbed dose measured with an ionization chamber of up to 40% in extreme cases. In this paper, we propose a method to calculate correction factors based on the Monte Carlo simulations. These correction factors are obtained by the ratio of the absorbed dose to water in a low-density medium □D(w,Q,V1)(low) averaged over a scoring volume V₁ for a geometry where V₁ is filled with the low-density medium and the absorbed dose to water □D(w,QV2)(low) averaged over a volume V₂ for a geometry where V₂ is filled with water. In the Monte Carlo simulations, □D(w,QV2)(low) is obtained by replacing the volume of the ionization chamber by an equivalent volume of water, according to the definition of the absorbed dose to water. The method is validated in two different configurations which allowed us to study the behavior of this correction factor as a function of depth in phantom, photon beam energy, phantom density and field size.
Velocity Correction and Measurement Uncertainty Analysis of Light Screen Velocity Measuring Method
Institute of Scientific and Technical Information of China (English)
ZHENG Bin; ZUO Zhao-lu; HOU Wen
2012-01-01
Light screen velocity measuring method with unique advantages has been widely used in the velocity measurement of various moving bodies.For large air resistance and friction force which the big moving bodies are subjected to during the light screen velocity measuring,the principle of velocity correction was proposed and a velocity correction equation was derived.A light screen velocity measuring method was used to measure the velocity of big moving bodies which have complex velocity attenuation,and the better results were gained in practical tests.The measuring uncertainty after the velocity correction was calculated.
Methods in pharmacology: measurement of cardiac output
Geerts, Bart F; Aarts, Leon P; Jansen, Jos R.
2011-01-01
Many methods of cardiac output measurement have been developed, but the number of methods useful for human pharmacological studies is limited. The ‘holy grail’ for the measurement of cardiac output would be a method that is accurate, precise, operator independent, fast responding, non-invasive, continuous, easy to use, cheap and safe. This method does not exist today. In this review on cardiac output methods used in pharmacology, the Fick principle, indicator dilution techniques, arterial pul...
Hourly Calculation Method of Air Source Heat Pump Behavior
Directory of Open Access Journals (Sweden)
Ludovico Danza
2016-04-01
Full Text Available The paper describes an hourly simplified model for the evaluation of the energy performance of heat pumps in cooling mode maintaining a high accuracy and low computational cost. This approach differs from the methods used for the assessment of the overall energy consumption of the building, normally placed in the so-called white or black box models, where the transient conduction equation is deterministically and stochastically solved, respectively. The present method wants to be the expression of the grey box model, taking place between the previous approaches. The building envelope is defined using a building thermal model realized with a 3 Resistance 1 Capacitance (3R1C thermal network based on the solution of the lumped capacitance method. The simplified model evaluates the energy efficiency ratio (EER of a heat pump through the determination of the hourly second law efficiency of a reversed Carnot cycle. The results of the simplified method were finally compared with those provided by EnergyPlus, a dynamic building energy simulation program, and those collected from an outdoor test cell in real working conditions. The results are presented in temperatures and energy consumptions profiles and are validated using the Bland-Altman test.
Energy Technology Data Exchange (ETDEWEB)
Wemhoener, C.; Dott, R.; Afjei, Th. [University of Applied Sciences Northwestern Switzerland, Institute of Energy in Buildings, Muttenz (Switzerland); Huber, H.; Helfenfinger, D.; Keller, P.; Furter, R. [University of Applied Sciences Lucerne (HTA), Test center HLKS, Horw (Switzerland)
2007-02-15
This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at compact heat pump units that have been developed for the heating of low energy consumption houses built to MINERGIE or MINERGIE-P standards. These units, which combine the functions of space heating, domestic hot water preparation and ventilation in one unit are described. A testing procedure developed at the University of Applied Science in Lucerne, Switzerland, using a test rig for the measurement of the seasonal performance factor (SPF) is described. A calculation method based on temperature classes for the calculation of the SPF of combined heat pump systems for space heating and domestic hot water preparation that was developed by the Institute of Energy in Buildings at the University of Applied Sciences Northwestern Switzerland is examined. Two pilot plants allowing detailed field monitoring of two compact units are described. One pilot plant installed in a single-family house built to MINERGIE standard in Gelterkinden, Switzerland, provided data on a compact unit. These results of measurements made on this and a further installation in a MINERGIE-P ultra-low energy consumption house in Zeiningen, Switzerland, are presented and discussed. Calculation methods, including exergy considerations are reviewed and their validation is discussed.
Helaly, Hany A.; El-Hifnawy, Mohammad A. M.; Shaheen, Mohamed Shafik; Abou El-Kheir, Amr F.
2016-01-01
Purpose: To evaluate the accuracy of corneal power measurements for intraocular lens (IOL) power calculation after myopic laser in situ keratomileusis (LASIK). Methods: The study evaluated 45 eyes with a history of myopic LASIK. Corneal power was measured using manual keratometry, automated keratometry, optical biometry, and Scheimflug tomography. Different hypothetical IOL power calculation formulas were performed for each case. Results: The steepest mean K value was measured with manual keratometry (37.48 ± 2.86 D) followed by automated keratometry (37.31 ± 2.83 D) then optical biometry (37.06 ± 2.98 D) followed by Scheimflug tomography (36.55 ± 3.08). None of the K values generated by Scheimflug tomography were steeper than the measurements from the other 3 instruments. Using equivalent K reading (EKR) 4 mm with the Double-K SRK/T formula, the refractive outcome generated 97.8% of cases within ± 2 D, 80.0% of cases within ± 1 D, and 42.2% of cases within ± 0.5 D. The best combination of formulas was “Shammas-PL + Double-K SRK/T formula using EKR 4 mm.” Conclusion: Scheimflug tomography imaging using the Holladay EKR 4 mm improved the accuracy of IOL power calculation in post-LASIK eyes. The best option is a combination of formulas. We recommended the use the combined “Shammas-PL ± Double-K SRK/T formula using EKR 4 mm”h for optical outcomes. PMID:26957851
Cao, Yang-Bing; Feng, Xia-Ting; Yan, E.-Chuan; Chen, Gang; Lü, Fei-fei; Ji, Hui-bin; Song, Kuang-Yin
2016-05-01
Knowledge of the fracture hydraulic aperture and its relation to the mechanical aperture and normal stress is urgently needed in engineering construction and analytical research at the engineering field scale. A new method based on the in situ borehole camera measurement and borehole water-pressure test is proposed for the calculation of the fracture hydraulic aperture. This method comprises six steps. The first step is to obtain the equivalent hydraulic conductivity of the test section from borehole water-pressure tests. The second step is a tentative calculation to obtain the qualitative relation between the reduction coefficient and the mechanical aperture obtained from borehole camera measurements. The third step is to choose the preliminary reduction coefficient for obtaining the initial hydraulic aperture. The remaining three steps are to optimize, using the genetic algorithm, the hydraulic apertures of fractures with high uncertainty. The method is then applied to a fractured granite engineering area whose purpose is the construction of an underground water-sealed storage cavern for liquefied petroleum gas. The probability distribution characteristics of the hydraulic aperture, the relationship between the hydraulic aperture and the mechanical aperture, the hydraulic aperture and the normal stress, and the differences between altered fractures and fresh fractures are all analyzed. Based on the effects of the engineering applications, the method is proved to be feasible and reliable. More importantly, the results of the hydraulic aperture obtained in this paper are different from those results elicited from laboratory tests, and the reasons are discussed in the paper.
Free-energy calculation methods for collective phenomena in membranes
International Nuclear Information System (INIS)
Collective phenomena in membranes are those which involve the co-operative reorganization of many molecules. Examples of these are membrane fusion, pore formation, bending, adhesion or fission. The time and length scales, on which these processes occur, pose a challenge for atomistic simulations. Therefore, in order to solve the length scale problem it is popular to introduce a coarse-grained representation. To facilitate sampling of the relevant states additional computational techniques, which encourage the system to explore the free-energy landscape far from equilibrium and visit transition states, are needed. These computational techniques provide insights about the free-energy changes involved in collective transformations of membranes, yielding information about the rate limiting states, the transformation mechanism and the influence of architectural, compositional and interaction parameters. A common approach is to identify an order parameter (or reaction coordinate), which characterizes the pathway of membrane reorganization. However, no general strategy exists to define such an order parameter that can properly describe cooperative reorganizations in membranes. Recently developed methods can overcome this problem of the order-parameter choice and allow us to study collective phenomena in membranes. We will discuss such methods as thermodynamic integration, umbrella sampling, and the string method and results provided by their applications to particle-based simulations, particularly focusing on membrane fusion and pore formation. (topical review)
A Stochastic Method for Semileptonic Form Factor Calculations on the Lattice
Evans, Richard; Collins, Sara
2009-01-01
We investigate an alternative to the Sequential Propagator Method used in Lattice QCD calculations of semileptonic form factors. We replace the sequential propagator with a stochastic propagator so that, in principle, all momentum and sink smearing combinations are available with only a single spin-color inversion. Practically, the stochastic noise is significant and must be reduced at the cost of more inversions. We study the behavior of the stochastic noise and compare the computational costs of this stochastic technique and the Sequential Propagator Method. We also present preliminary semileptonic form factor results using the stochastic technique on N_f=2 configurations with a non-perturbatively improved Sheikoleslami-Wohlert action generated by the QCDSF collaboration. At a fixed cost, measured in terms of the number of heavy-quark inversions, the method provides more correlators for the extraction of the form factors at various q^2's than the Sequential Propagator Method. These additional correlators re...
The truth is out there: measured, calculated and modelled benthic fluxes.
Pakhomova, Svetlana; Protsenko, Elizaveta
2016-04-01
water. Values of benthic fluxes obtained by the BROM model are within the range of magnitudes measured by chamber experiments and calculated from porewater distributions (Jpw changing largely while in chamber experiments they are averaged. As a result, each of the methods has its disadvantages and the main facing us question is - which value should be taken for calculation the balance? This research is funded by VISTA - a basic research program and collaborative partnership between the Norwegian Academy of Science and Letters and Statoil.
A Comparison of Model Calculation and Measurement of Absorbed Dose for Proton Irradiation. Chapter 5
Zapp, N.; Semones, E.; Saganti, P.; Cucinotta, F.
2003-01-01
With the increase in the amount of time spent EVA that is necessary to complete the construction and subsequent maintenance of ISS, it will become increasingly important for ground support personnel to accurately characterize the radiation exposures incurred by EVA crewmembers. Since exposure measurements cannot be taken within the organs of interest, it is necessary to estimate these exposures by calculation. To validate the methods and tools used to develop these estimates, it is necessary to model experiments performed in a controlled environment. This work is such an effort. A human phantom was outfitted with detector equipment and then placed in American EMU and Orlan-M EVA space suits. The suited phantom was irradiated at the LLUPTF with proton beams of known energies. Absorbed dose measurements were made by the spaceflight operational dosimetrist from JSC at multiple sites in the skin, eye, brain, stomach, and small intestine locations in the phantom. These exposures are then modeled using the BRYNTRN radiation transport code developed at the NASA Langley Research Center, and the CAM (computerized anatomical male) human geometry model of Billings and Yucker. Comparisons of absorbed dose calculations with measurements show excellent agreement. This suggests that there is reason to be confident in the ability of both the transport code and the human body model to estimate proton exposure in ground-based laboratory experiments.
An improved filtered spherical harmonic method for transport calculations
Energy Technology Data Exchange (ETDEWEB)
Ahrens, C. [Department of Applied Mathematics and Statistics, Colorado School of Mines, Golden, CO 80401 (United States); Merton, S. [Computational Physics Group, AWE Aldermaston, Berkshire (United Kingdom)
2013-07-01
Motivated by the work of R. G. McClarren, C. D. Hauck, and R. B. Lowrie on a filtered spherical harmonic method, we present a new filter for such numerical approximations to the multi-dimensional transport equation. In several test problems, we demonstrate that the new filter produces results with significantly less Gibbs phenomena than the filter used by McClarren, Hauck and Lowrie. This reduction in Gibbs phenomena translates into propagation speeds that more closely match the correct propagation speed and solutions that have fewer regions where the scalar flux is negative. (authors)
Visual Method for Spectral Energy Distribution Calculation of Blazars
Indian Academy of Sciences (India)
Y. Huang; J. H. Fan
2014-09-01
In this work, we propose to use `The Geometer’s Sketchpad’ to the fitting of a spectral energy distribution of blazar based on three effective spectral indices, RO, OX, and RX and the flux density in the radio band. It can make us to see the fitting in detail with both the peak frequency and peak luminosity given immediately. We used our method to those sources whose peak frequency and peak luminosity are given and found that our results are consistent with those given in the work of Sambruna et al. (1996).
Rate Constant Calculation for Thermal Reactions Methods and Applications
DaCosta, Herbert
2011-01-01
Providing an overview of the latest computational approaches to estimate rate constants for thermal reactions, this book addresses the theories behind various first-principle and approximation methods that have emerged in the last twenty years with validation examples. It presents in-depth applications of those theories to a wide range of basic and applied research areas. When doing modeling and simulation of chemical reactions (as in many other cases), one often has to compromise between higher-accuracy/higher-precision approaches (which are usually time-consuming) and approximate/lower-preci
Lidar Measurements Supporting the Ocular Hazard Distance Calculation Using Atmospheric Attenuation
Gustafsson, K. Ove S.; Persson, Rolf; Gustafsson, Frank; Berglund, Folke; Hedborg, Julia; Malmquist, Jonas
2016-06-01
A series of lidar measurements has been performed at the Vidsel Test Range, Vidsel, situated in the inland of the very northern part of Sweden, as a part of an assessment of reducing the laser hazard distance using atmospheric attenuation within the calculations of nominal ocular hazard distance (NOHD). The question was "How low is the atmospheric attenuation as function of height in this area, using a wavelength of 1064 nm?" The work included building a ground based backscatter lidar, performing a series of measurements and analyzing the results. The measurements were performed during June to November, 2014, with the objective to measure at clear air and good weather situations. The lidar measurements at 1064 nm showed a very low atmospheric attenuation as a function of height to altitudes of at least 10 km at several occasions. The lowest limit of backscatter coefficient possible to measure with this instrument is 0.3·10-7 m-1 sr-1. Assuming a lidar ratio varying between 30 - 100 sr, this was leading to an extinction coefficient of about 0.9 - 3·10-6 m-1. The atmospheric attenuation reduces the laser hazard distance with about 50 - 56 % depending on the lidar ratio. A recommendation is to monitor the atmospheric attenuation at the occasions when the method to the reduced laser hazard distance using atmospheric attenuation is used.
Comparison of hardenability calculation methods of the heat-treatable constructional steels
Energy Technology Data Exchange (ETDEWEB)
Dobrzanski, L.A.; Sitek, W. [Division of Tool Materials and Computer Techniques in Metal Science, Silesian Technical University, Gliwice (Poland)
1995-12-31
Evaluation has been made of the consistency of calculation of the hardenability curves of the selected heat-treatable alloyed constructional steels with the experimental data. The study has been conducted basing on the analysis of present state of knowledge on hardenability calculation employing the neural network methods. Several calculation examples and comparison of the consistency of calculation methods employed are included. (author). 35 refs, 2 figs, 3 tabs.
Utilization of Software Tools for Uncertainty Calculation in Measurement Science Education
International Nuclear Information System (INIS)
Despite its importance, uncertainty is often neglected by practitioners in the design of system even in safety critical applications. Thus, problems arising from uncertainty may only be identified late in the design process and thus lead to additional costs. Although there exists numerous tools to support uncertainty calculation, reasons for limited usage in early design phases may be low awareness of the existence of the tools and insufficient training in the practical application. We present a teaching philosophy that addresses uncertainty from the very beginning of teaching measurement science, in particular with respect to the utilization of software tools. The developed teaching material is based on the GUM method and makes use of uncertainty toolboxes in the simulation environment. Based on examples in measurement science education we discuss advantages and disadvantages of the proposed teaching philosophy and include feedback from students
Institute of Scientific and Technical Information of China (English)
TANG Yi; FANG Yong-li; YANG Luo; SUN Yu-xin; YU Zheng-hua
2012-01-01
A new accurate calculation method of electric power harmonic parameters was presented.Based on the delay time theorem of Fourier transform,the frequency of the electric power was calculated,and then,suing interpolation in the frequency domain of the windows,the parameters (amplitude and phase) of each harmonic frequency signals were calculated accurately.In the paper,the effect of the delay time and the windows on the electric power harmonic calculation accuracy was analysed.The digital simulation and the physical measurement tests show that the proposed method is effective and has more advantages than other methods which are based on multipoint interpolation especially in calculation time cost; therefore,it is very suitable to be used in the single chip DSP micro-processor.
Method of measuring luminescence of a material
Miller, Steven D.
2015-12-15
A method of measuring luminescence of a material is disclosed. The method includes applying a light source to excite an exposed material. The method also includes amplifying an emission signal of the material. The method further includes measuring a luminescent emission at a fixed time window of about 10 picoseconds to about 10 nanoseconds. The luminescence may be radio photoluminescence (RPL) or optically stimulated luminescence (OSL).
Recommended environmental dose calculation methods and Hanford-specific parameters
Energy Technology Data Exchange (ETDEWEB)
Schreckhise, R.G.; Rhoads, K.; Napier, B.A.; Ramsdell, J.V. (Pacific Northwest Lab., Richland, WA (United States)); Davis, J.S. (Westinghouse Hanford Co., Richland, WA (United States))
1993-03-01
This document was developed to support the Hanford Environmental Dose overview Panel (HEDOP). The Panel is responsible for reviewing all assessments of potential doses received by humans and other biota resulting from the actual or possible environmental releases of radioactive and other hazardous materials from facilities and/or operations belonging to the US Department of Energy on the Hanford Site in south-central Washington. This document serves as a guide to be used for developing estimates of potential radiation doses, or other measures of risk or health impacts, to people and other biota in the environs on and around the Hanford Site. It provides information to develop technically sound estimates of exposure (i.e., potential or actual) to humans or other biotic receptors that could result from the environmental transport of potentially harmful materials that have been, or could be, released from Hanford operations or facilities. Parameter values and information that are specific to the Hanford environs as well as other supporting material are included in this document.
Control rod worth calculations using deterministic and stochastic methods
Energy Technology Data Exchange (ETDEWEB)
Varvayanni, M. [NCSR ' DEMOKRITOS' , PO Box 60228, 15310 Aghia Paraskevi (Greece); Savva, P., E-mail: melina@ipta.demokritos.g [NCSR ' DEMOKRITOS' , PO Box 60228, 15310 Aghia Paraskevi (Greece); Catsaros, N. [NCSR ' DEMOKRITOS' , PO Box 60228, 15310 Aghia Paraskevi (Greece)
2009-11-15
Knowledge of the efficiency of a control rod to absorb excess reactivity in a nuclear reactor, i.e. knowledge of its reactivity worth, is very important from many points of view. These include the analysis and the assessment of the shutdown margin of new core configurations (upgrade, conversion, refuelling, etc.) as well as several operational needs, such as calibration of the control rods, e.g. in case that reactivity insertion experiments are planned. The control rod worth can be assessed either experimentally or theoretically, mainly through the utilization of neutronic codes. In the present work two different theoretical approaches, i.e. a deterministic and a stochastic one are used for the estimation of the integral and the differential worth of two control rods utilized in the Greek Research Reactor (GRR-1). For the deterministic approach the neutronics code system SCALE (modules NITAWL/XSDRNPM) and CITATION is used, while the stochastic one is made using the Monte Carlo code TRIPOLI. Both approaches follow the procedure of reactivity insertion steps and their results are tested against measurements conducted in the reactor. The goal of this work is to examine the capability of a deterministic code system to reliably simulate the worth of a control rod, based also on comparisons with the detailed Monte Carlo simulation, while various options are tested with respect to the deterministic results' reliability.
Comparisons of Measured and Calculated Neutron Fluxes in Laminated iron and Heavy Water
International Nuclear Information System (INIS)
Measurements of neutron fluxes have been performed in configurations depicting the regions extending radially and axially outwards from the core of a PHWR reactor in order to test the accuracy of the available methods in shield design on thin alternating laminae of Fe and D2O. A 'dry' experimental set-up was constructed, i.e. the D2O was contained in flat tanks made of Al. The first set of measurements was performed through solid Fe and D2O layers, and only the results of these experiments are described in this report. The set-up allowed measurements also in a mock-up of a reactor top penetrated by D2O or air-filled channels (to be reported later). The results are compared to fluxes calculated by the British 18-group removal-diffusion method and by the NRN method developed at AE. The results show that the values predicted may be expected to be within a factor of 2 from the true values in most cases. The predicted relative flux distributions follow the observed ones with a very good accuracy in spite of the apparent misuse of diffusion theory for the thin regions in question. Finally, it is shown that the predicted change in the fast spectrum while penetrating these set-ups should be confirmable with certain threshold detectors
Theory and Method of Commercial Bank Credit Risk Measurement
Institute of Scientific and Technical Information of China (English)
BeimingXiao; JinlinLi
2004-01-01
Calculating and measuring credit risk is the key technique of commercial bank management. International relative achievements mainly include Z and ZETA modelof Altman, Standard&pool external rating system, Moody external rating system, KMV model, CreditMetrics model, CreditRisk model, McKinsey model and so on. Chinese relative achievements mainly includes: credit score method, comprehensive estimating method,discriminative analysis method, artificial neural network method etc. This paper analyzes the relative research achievements of credit risk measurement and the future research trend.
A comparison of measured and calculated organ doses from CT examinations
Energy Technology Data Exchange (ETDEWEB)
Calzado, A.; Ruiz Sanz, S.; Melchor, M.; Vano, E. [Universidad Complutense, Madrid (Spain). Facultad de Medicina
1995-12-31
Organ doses from a set of frequent CT examinations have been estimated from measurements in a physical anthropomorphic phantom (Remab system) by using thermoluminescence dosemeters. For the same examination techniques, organ dose coefficients (taken from the literature) obtained by Monte Carlo techniques and using mathematical phantoms. The results arrived at by the two methods are compared, trying to explain the most significant differences and their influence on the estimated values of effective dose. The experimental and calculated outcomes from such simulations are also compared to the mean dosimetric results on patients from a 1991 regional survey of CT practice in the area of Madrid. Some comments about the complementary use of information coming from both methods are made. (Author).
Beatriz Machado Fontes; Bruno Machado Fontes; Elaine Castro
2011-01-01
PURPOSE: To compare the achieved refractive outcomes of patients undergoing cataract surgery with intraocular lens (IOL) power calculation performed by conventional immersion ultrasound (US) or partial coherence interferometry (PCI). METHODS: Prospective, comparative case series. Patients undergoing cataract surgery were randomly divided in two groups with regard to the IOL power calculation method. Group 1 had calculations performed by PCI (IOL Master; Carl Zeiss Meditec), while US was used ...
Study on the Processing Method for Resonance Self-shielding Calculations
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
We investigate a new approach for resonance self-shielding calculations, based on a straightforward subgroup method, used in association with characteristics method. Subgroup method is actually the subdivision of cross section range for resonance energy range.
Directory of Open Access Journals (Sweden)
Odru P.
2006-11-01
Full Text Available Cet article présente une méthode de calcul des structures composites fibres-résine appliquée aux cas des tubes minces. Outre l'établissement des relations contraintes - déformations généralisées des tubes à partir des caractéristiques des matériaux de base et de leur orientation, on pose les relations permettant de calculer leur comportement et leur dimensionnement sous des charges axisymétriques combinées de traction, pression et flexion. Une méthode simplifiée applicable au cas des composites microfissurés est aussi présentée. On montre ensuite, à travers quelques exemples concrets d'applications, les propriétés intéressantes ou inhabituelles que le matériau permet de conférer aux structures. This article presents a method of calculation of composite structures applied to thin-walled tubes. Starting from the characteristics and orientation of the basic materials, the generalized stress-strain equations of the tubes are determined ; then the relationship allowing the calculation of their design and behavior under combined axisymmetrical loads of tension, pressure and bending are established. A simplified method applicable to microcracked composite materials is also described. Several complete examples of applications illustrate the interesting or unusual properties that this material can impart to structures
Gomez, Susan F.; Hood, Laura; Panneton, Robert J.; Saunders, Penny E.; Adkins, Antha; Hwu, Shian U.; Lu, Ba P.
1996-01-01
Two computational techniques are used to calculate differential phase errors on Global Positioning System (GPS) carrier war phase measurements due to certain multipath-producing objects. The two computational techniques are a rigorous computati electromagnetics technique called Geometric Theory of Diffraction (GTD) and the other is a simple ray tracing method. The GTD technique has been used successfully to predict microwave propagation characteristics by taking into account the dominant multipath components due to reflections and diffractions from scattering structures. The ray tracing technique only solves for reflected signals. The results from the two techniques are compared to GPS differential carrier phase ns taken on the ground using a GPS receiver in the presence of typical International Space Station (ISS) interference structures. The calculations produced using the GTD code compared to the measured results better than the ray tracing technique. The agreement was good, demonstrating that the phase errors due to multipath can be modeled and characterized using the GTD technique and characterized to a lesser fidelity using the DECAT technique. However, some discrepancies were observed. Most of the discrepancies occurred at lower devations and were either due to phase center deviations of the antenna, the background multipath environment, or the receiver itself. Selected measured and predicted differential carrier phase error results are presented and compared. Results indicate that reflections and diffractions caused by the multipath producers, located near the GPS antennas, can produce phase shifts of greater than 10 mm, and as high as 95 mm. It should be noted tl the field test configuration was meant to simulate typical ISS structures, but the two environments are not identical. The GZ and DECAT techniques have been used to calculate phase errors due to multipath o the ISS configuration to quantify the expected attitude determination errors.
Theories and calculation methods for regional objective ET
Institute of Scientific and Technical Information of China (English)
QIN DaYong; LO JinYan; LIU JiaHong; WANG MingNa
2009-01-01
The regional objective ET (Evapotranspiration) is a new concept in water resources research, which refers to the total amount of water that could be exhausted from a region in the form of vapor per year. The objective-ET based water resources management allocates water to different regions in terms of ET. It controls the water exhausted from a region to meet the objective ET. The regional objective ET must be adapted to fit the region's local available water resources. By improving the water utilization effi-ciency and reducing the unrecoverable water in the social water circle, it is saved so that water related production is maintained or even increased under the same water consumption conditions. Regional water balance is realized by rationally deploying the available water among different industries, adjusting industrial structures, and adopting new water-saving technologies, therefore to meeting the requirements for groundwater conservation, agricultural income stability, and avoiding environmental damages. Furthermore, water competition among various departments and industries (including envi-ronmental and ecological water use) may be avoided. This paper proposes an innovative definition of objective ET, and its principles, sub-index systems. Besides, a computational method for regional ob-jective ET is developed by combining the distributed hydrological model and the soil moisture model.
International Nuclear Information System (INIS)
The characteristics of the epithermal neutron beam at BMRR were measured, calculated, and reported by R.G. Fairchild. This beam has already been used for animal irradiations. The authors anticipate that it will be used for clinical trials. Thermal and epithermal neutron flux densities distributions, and dose rate distributions, as a function of depth were measured in a lucite dog-head phantom. Monte Carlo calculations were performed and compared with the measured values
Measured and Monte Carlo calculated k{sub Q} factors: Accuracy and comparison
Energy Technology Data Exchange (ETDEWEB)
Muir, B. R.; McEwen, M. R.; Rogers, D. W. O. [Ottawa Medical Physics Institute (OMPI), Ottawa Carleton Institute for Physics, Carleton University Campus, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada); Institute for National Measurement Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada); Ottawa Medical Physics Institute (OMPI), Ottawa Carleton Institute for Physics, Carleton University Campus, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 (Canada)
2011-08-15
Purpose: The journal Medical Physics recently published two papers that determine beam quality conversion factors, k{sub Q}, for large sets of ion chambers. In the first paper [McEwen Med. Phys. 37, 2179-2193 (2010)], k{sub Q} was determined experimentally, while the second paper [Muir and Rogers Med. Phys. 37, 5939-5950 (2010)] provides k{sub Q} factors calculated using Monte Carlo simulations. This work investigates a variety of additional consistency checks to verify the accuracy of the k{sub Q} factors determined in each publication and a comparison of the two data sets. Uncertainty introduced in calculated k{sub Q} factors by possible variation of W/e with beam energy is investigated further. Methods: The validity of the experimental set of k{sub Q} factors relies on the accuracy of the NE2571 reference chamber measurements to which k{sub Q} factors for all other ion chambers are correlated. The stability of NE2571 absorbed dose to water calibration coefficients is determined and comparison to other experimental k{sub Q} factors is analyzed. Reliability of Monte Carlo calculated k{sub Q} factors is assessed through comparison to other publications that provide Monte Carlo calculations of k{sub Q} as well as an analysis of the sleeve effect, the effect of cavity length and self-consistencies between graphite-walled Farmer-chambers. Comparison between the two data sets is given in terms of the percent difference between the k{sub Q} factors presented in both publications. Results: Monitoring of the absorbed dose calibration coefficients for the NE2571 chambers over a period of more than 15 yrs exhibit consistency at a level better than 0.1%. Agreement of the NE2571 k{sub Q} factors with a quadratic fit to all other experimental data from standards labs for the same chamber is observed within 0.3%. Monte Carlo calculated k{sub Q} factors are in good agreement with most other Monte Carlo calculated k{sub Q} factors. Expected results are observed for the sleeve
The truth is out there: measured, calculated and modelled benthic fluxes.
Pakhomova, Svetlana; Protsenko, Elizaveta
2016-04-01
.) are faster than diffusion and play an important role in the benthic flux formation for these elements. For the third group measured fluxes could be often overestimated, especially for coastal shallow stations, up to 50%, because of intensive decomposition of OM and/or organisms respiration in the isolated bottom water. Values of benthic fluxes obtained by the BROM model are within the range of magnitudes measured by chamber experiments and calculated from porewater distributions (Jpw < Jmd < Jch). Using the model it is possible estimate the influence of bioturbation on elements exchange at water-sediment interface. Model has a high resolution in the upper sediment (0.1 mm) that gives the advantage of a more accurate calculation of diffusive fluxes especially for redox dependent elements. Model results showed that in 50 cm above the sediment vertical fluxes are changing largely while in chamber experiments they are averaged. As a result, each of the methods has its disadvantages and the main facing us question is - which value should be taken for calculation the balance? This research is funded by VISTA - a basic research program and collaborative partnership between the Norwegian Academy of Science and Letters and Statoil.
A method to improve the precision of measuring focusing system
Xu, Xiaoliang; An, Tao; Chen, Ke
2015-10-01
Most of the telescope focusing systems adopt the measuring distance method to focus the quick-moving target because the imaging position of moving target is constantly changing. The focusing system calculates the focal position, controls the motor according to the distance of the target. This focusing method has a faster focusing and a better real-time performance compared to the image focusing method based on the image quality. But restricted by the external environment, the precision of instruments and technical level, Distance measuring focus system(DMFS) generally have low precision, higher dynamic adjusting delay problem. This paper mainly analyses the main error sources affecting the accuracy of DMFS, aiming at the existing defects of commonly used current speed compensation method, put forward a kind of solution path delay lag method predicted method measuring focusing system, and then simulate it, the result shows that this method can greatly improve the precision of DMFS.
Energy Technology Data Exchange (ETDEWEB)
Sin, M. W.; Kim, M. H. [Kyunghee Univ., Yongin (Korea, Republic of)
2002-10-01
To calculate total dose effect on semi-conductor devices in satellite for a period of space mission effectively, two approximate calculation models for a comic radiation shielding were proposed. They are a sectoring method and a chord-length distribution method. When an approximate method was applied in this study, complex structure of satellite was described into multiple 1-dimensional slabs, structural materials were converted to reference material(aluminum), and the pre-calculated dose-depth conversion function was introduced to simplify the calculation process. Verification calculation was performed for orbit location and structure geometry of KITSAT-1 and compared with detailed 3-dimensional calculation results and experimental values. The calculation results from approximate method were estimated conservatively with acceptable error. However, results for satellite mission simulation were underestimated in total dose rate compared with experimental values.
An efficient k.p method for calculation of total energy and electronic density of states
Iannuzzi, M; Iannuzzi, Marcella; Parrinello, Michele
2001-01-01
An efficient method for calculating the electronic structure in large systems with a fully converged BZ sampling is presented. The method is based on a k.p-like approximation developed in the framework of the density functional perturbation theory. The reliability and efficiency of the method are demostrated in test calculations on Ar and Si supercells.
Perturbation method for calculation of narrow-band impedance and trapped modes
International Nuclear Information System (INIS)
An iterative method for calculation of the narrow-band impedance is described for a system with a small variation in boundary conditions, so that the variation can be considered as a perturbation. The results are compared with numeric calculations. The method is used to relate the origin of the trapped modes with the degeneracy of the spectrum of an unperturbed system. The method also can be applied to transverse impedance calculations. 6 refs., 6 figs., 1 tab
Handbook of nuclear safeguards measurement methods
International Nuclear Information System (INIS)
This handbook is intended to be a guide to the selection of methods for meeting specific measurement requirements. The information was compiled from a survey of production facilities, the literature, and current exchange programs. The survey included bulk measurements, chemical assay, sampling techniques, isotopic measurements, passive NDA, and active NDA
Energy Technology Data Exchange (ETDEWEB)
Furnish, M.D.; Boslough, M.B. [Sandia National Labs., Albuquerque, NM (United States); Gray, G.T. III [Los Alamos National Lab., NM (United States); Remo, J.L. [Quantametrics, Inc., St. James, NY (United States)
1994-07-01
We describe methods for measuring dynamical properties for two material categories of interest in understanding large-scale extraterrestrial impacts: iron-nickel and underdense materials (e.g. snow). Particular material properties measured by the present methods include Hugoniot release paths and constitutive properties (stress vs. strain). The iron-nickel materials lend themselves well to conventional shock and quasi-static experiments. As examples, a suite of experiments is described including six impact tests (wave profile compression/release) over the stress range 2--20 GPa, metallography, quasi-static and split Hopkinson pressure bar (SHPB) mechanical testing, and ultrasonic mapping and sound velocity measurements. Temperature sensitivity of the dynamic behavior was measured at high and low strain rates. Among the iron-nickel materials tested, an octahedrite was found to have behavior close to that of Armco iron under shock and quasi-static conditions, while an ataxite exhibited a significantly larger quasi-static yield strength than did the octahedrite or a hexahedrite. The underdense materials pose three primary experimental difficulties. First, the samples are friable; they can melt or sublimate during storage, preparation and testing. Second, they are brittle and crushable; they cannot withstand such treatment as traditional machining or launch in a gun system. Third, with increasing porosity the calculated Hugoniot density becomes rapidly more sensitive to errors in wave time-of-arrival measurements. Carefully chosen simulants eliminate preservation (friability) difficulties, but the other difficulties remain. A family of 36 impact tests was conducted on snow and snow simulants at Sandia, yielding reliable Hugoniot and reshock states, but limited release property information. Other methods for characterizing these materials are discussed.
Contemporary methods of body composition measurement
DEFF Research Database (Denmark)
Fosbøl, Marie Ø; Zerahn, Bo
2015-01-01
Reliable and valid body composition assessment is important in both clinical and research settings. A multitude of methods and techniques for body composition measurement exist, all with inherent problems, whether in measurement methodology or in the assumptions upon which they are based....... This review is focused on currently applied methods for in vivo measurement of body composition, including densitometry, bioimpedance analysis, dual-energy X-ray absorptiometry, computed tomography (CT), magnetic resonance techniques and anthropometry. Multicompartment models including quantification of trace...
Directory of Open Access Journals (Sweden)
Mikulović Jovan Č.
2014-01-01
Full Text Available A methodology for calculation of overvoltages in transformer windings, based on a numerical method of inverse Laplace transform, is presented. Mathematical model of transformer windings is described by partial differential equations corresponding to distributed parameters electrical circuits. The procedure of calculating overvoltages is applied to windings having either isolated neutral point, or grounded neutral point, or neutral point grounded through impedance. A comparative analysis of the calculation results obtained by the proposed numerical method and by analytical method of calculation of overvoltages in transformer windings is presented. The results computed by the proposed method and measured voltage distributions, when a voltage surge is applied to a three-phase 30 kVA power transformer, are compared. [Projekat Ministartsva nauke Republike Srbije, br. TR-33037 i br. TR-33020
Measured and calculated effective delayed neutron fraction of the IPR-R1 Triga reactor
Energy Technology Data Exchange (ETDEWEB)
Souza, Rose Mary G.P.; Dalle, Hugo M.; Campolina, Daniel A.M., E-mail: souzarm@cdtn.b, E-mail: dallehm@cdtn.b, E-mail: campolina@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)
2011-07-01
The effective delayed neutron fraction, {beta}{sub eff}, one of the most important parameter in reactor kinetics, was measured for the 100 kW IPR-R1 TRIGA Mark I research reactor, located at the Nuclear Technology Development Center - CDTN, Belo Horizonte, Brazil. The current reactor core has 63 fuel elements, containing about 8.5% and 8% by weight of uranium enriched to 20% in U{sup 235}. The core has cylindrical configuration with an annular graphite reflector. Since the first criticality of the reactor in November 1960, the core configuration and the number of fuel elements have been changed several times. At that time, the reactor power was 30 kW, there were 56 fuel elements in the core, and the {beta}{sub eff} value for the reactor recommended by General Atomic (manufacturer of TRIGA) was 790 pcm. The current {beta}{sub eff} parameter was determined from experimental methods based on inhour equation and on the control rod drops. The estimated values obtained were (774 {+-} 38) pcm and (744 {+-} 20) pcm, respectively. The {beta}{sub eff} was calculated by Monte Carlo transport code MCNP5 and it was obtained 747 pcm. The calculated and measured values are in good agreement, and the relative percentage error is -3.6% for the first case, and 0.4% for the second one. (author)
Hybrid analytic-numeric calculation method for light through a bounded planar dielectric
Nicolau, J.B.; Groesen, van E.
2005-01-01
We present a hybrid analytic-numeric method to calculate the transmission and reflection of light that is fluxed into a bounded complicated optical structure surrounded by air. The solution is obtained by numerical calculations inside a square containing the structure and by analytical calculations
Field methods for measuring concentrated flow erosion
Castillo, C.; Pérez, R.; James, M. R.; Quinton, J. N.; Taguas, E. V.; Gómez, J. A.
2012-04-01
Many studies have stressed the importance of gully erosion in the overall soil loss and sediment yield of agricultural catchments, for instance in recent years (Vandaele and Poesen, 1995; De Santisteban et al., 2006; Wu el al, 2008). Several techniques have been used for determining gully erosion in field studies. The conventional techniques involved the use of different devices (i.e. ruler, pole, tape, micro-topographic profilers, total station) to calculate rill and gully volumes through the determination of cross sectional areas and length of reaches (Casalí et al, 1999; Hessel and van Asch, 2003). Optical devices (i.e. laser profilemeters) have also been designed for the purpose of rapid and detailed assessment of cross sectional areas in gully networks (Giménez et al., 2009). These conventional 2d methods provide a simple and un-expensive approach for erosion evaluation, but are time consuming to carry out if a good accuracy is required. On the other hand, remote sensing techniques are being increasingly applied to gully erosion investigation such as aerial photography used for big-scale, long-term, investigations (e.g. Martínez-Casasnovas et al., 2004; Ionita, 2006), airborne and terrestrial LiDAR datasets for gully volume evaluation (James et al., 2007; Evans and Lindsay, 2010) and recently, major advances in 3D photo-reconstruction techniques (Welty et al. 2010, James et al., 2011). Despite its interest, few studies simultaneously compare the accuracies of the range of conventional and remote sensing techniques used, or define the most suitable method for a particular scale, given and time and cost constraints. That was the reason behind the International Workshop Innovations in the evaluation and measurement of rill and gully erosion, held in Cordoba in May 2011 and from which derive part of the materials presented in this abstract. The main aim of this work was to compare the accuracy and time requirements of traditional (2D) and recently developed
Method for Measuring Changes in Surface Tension on Agar
Weisberg, David S.; Dworkin, Martin
1983-01-01
The surface tension of agar surfaces was determined by measuring the contact angles formed by drops of various hydrophobic liquids on the surface and then calculating the composite surface free energy function by solving a series of simultaneous equations derived from these data. This method was used to measure the change in the surface tension of agar produced by the addition of various concentrations of albumin. The resulting curve was typical of the effect of increasing concentrations of s...
A new method for calculating the activity of stable compound from binary phase diagram
Institute of Scientific and Technical Information of China (English)
CHEN Dengfu; DONG Lingyan; BAI Chenguang; LIU Qingcai; WANG Chuanjun
2006-01-01
A new method to calculate the activity of a stable compound in a binary phase diagram was presented and dis cussed. According to the formula for calculating activity from the binary phase diagram, the equilibrium constant can be calculated through the mass action principle after the activities of two pure components were computed respectively. Based on that, the activity of a stable compound can be easily obtained at last. The activity of the stable compound InSb is calculated in the In-Sb binary system by using this method. The result is well consistent with another calculation value.
THE PARTICULARITIES OF THE COST CALCULATION METHOD ON COMMANDS IN FURNITURE INDUSTRY
Felicia Sabou
2014-01-01
The paper present the importance of the method on commands in cost calculation and the particularities of the cost calculation method on commands in the furniture industry. This paper presents a hypotetical study on the method on commands, considering the observations made during 2013-2014, on how it is organized and managed accounts management using method on commands.By presenting this hypothetical model about the accounting in management accounting using the method on commands, the pape...
Institute of Scientific and Technical Information of China (English)
李春娟; 刘毅娜; 张伟华; 王志强
2014-01-01
The manganese bath method for measuring the neutron emission rate of radio-nuclide sources requires corrections to be made for emitted neutrons w hich are not cap-tured by manganese nuclei .The Monte Carlo particle transport code MCNP was used to simulate the manganese bath system of the standards for the measurement of neutron source intensity .The correction factors were calculated and the reliability of the model was demonstrated through the key comparison for the radionuclide neutron source emis-sion rate measurements organized by BIPM .The uncertainties in the calculated values were evaluated by considering the sensitivities to the solution density ,the density of the radioactive material ,the positioning of the source ,the radius of the bath ,and the inter-action cross-sections .A new method for the evaluation of the uncertainties in Monte Carlo calculation was given .%在采用锰浴法对放射性同位素中子源的发射率进行测量时，M nSO4溶液中55 M n仅俘获部分源中子，故需考虑对未被55 Mn俘获部分的修正。用蒙特卡罗粒子输运程序MCNP对中子源强标准装置的锰浴系统进行模拟计算，对实验测量结果进行修正，并通过由国际计量局（BIPM ）组织的中子源强度国际比对，验证了计算所建立模型的可靠性。利用MCNP程序的微扰计算功能，通过考虑MnSO4溶液的密度、源及其承托物材料的密度、源的位置、锰浴半径以及反应截面的改变对计算结果的影响，对模拟计算结果的不确定度进行了详细评定，提供了一种蒙特卡罗模拟计算结果不确定度的评定方法。
Shan Yang; Xiangqian Tong
2016-01-01
Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverte...
Zhang, Zhiqiang; Geng, Dalong; Wang, Xudong
2016-04-01
A simple and effective decoupled finite element analysis method was developed for simulating both the piezoelectric and flexoelectric effects of zinc oxide (ZnO) and barium titanate (BTO) nanowires (NWs). The piezoelectric potential distribution on a ZnO NW was calculated under three deformation conditions (cantilever, three-point, and four-point bending) and compared to the conventional fully coupled method. The discrepancies of the electric potential maximums from these two methods were found very small, validating the accuracy and effectiveness of the decoupled method. Both ZnO and BTO NWs yielded very similar potential distributions. Comparing the potential distributions induced by the piezoelectric and flexoelectric effects, we identified that the middle segment of a four-point bending NW beam is the ideal place for measuring the flexoelectric coefficient, because the uniform parallel plate capacitor-like potential distribution in this region is exclusively induced by the flexoelectric effect. This decoupled method could provide a valuable guideline for experimental measurements of the piezoelectric effects and flexoelectric effects in the nanometer scale.
Method effects and the meaning of measurement
Directory of Open Access Journals (Sweden)
Andrew eMaul
2013-04-01
Full Text Available Although the idea of a method effect in psychological measurement seems intuitively straightforward—that is, it is said to occur when any characteristic of a measurement procedure contributes variance to scores beyond what is attributable to variance in the attribute of interest—much of the surrounding conceptual vocabulary remains confused. In part, these confusions can be traced to deeper confusion in the human science literature regarding the meaning of measurement. In particular, the thinking of human scientists about method effects has been shaped by (a received wisdom regarding why method effects are problematic to begin with, and, therefore, what corrective measures are appropriate, (b the formal and implied semantics of psychometric techniques that have been developed to model method effects, and (c general philosophical undercurrents that have contributed to the collective understanding of psychological measurement. Notably, tensions between lines of thought that can be broadly characterized as empiricist and realist have contributed to uneven thinking surrounding the concept of a method effect. In this paper, it is argued that it may be possible to formulate an account of what method effects are that is coherent not only across different research traditions in the human sciences, but also with thinking found in other scientific disciplines; however, doing so requires a more explicit commitment to a realist position on measurement than is generally forthcoming from human scientists. By examining these issues, this paper hopes to contribute to semantic clarity regarding not just method effects, but also the meaning of measurement in psychology.
Validity of hearing impairment calculation methods for prediction of self-reported hearing handicap
Directory of Open Access Journals (Sweden)
Andrew B John
2012-01-01
Full Text Available Worker′s compensation for hearing loss caused by occupational noise exposure is calculated by varying methods, from state to state within the United States (US, with many employing arithmetic formulas based on the pure-tone audiogram, to quantify hearing loss. Several assumptions unsupported or weakly supported by empirical data underlie these formulas. The present study evaluated the ability of various arithmetic hearing impairment calculations to predict a self-reported hearing handicap in a sample of presenting with sensorineural hearing loss. 204 adults (127 male, 77 female ranging in age from 18 to 94 served as participants. The sample was selected to exclude patients who had been referred for hearing testing for a medicolegal examination or a hearing conservation appointment. A hearing handicap was measured by the Hearing Handicap Inventory for Adults/for the Elderly (HHIA/E. The covariance analysis of linear structural equations was used to assess the relative strength of correlation with the HHIA/E score among the six formulas and various forms of pure-tone average. The results revealed that all the hearing impairment calculations examined were significantly, but weakly, correlated with the self-reported hearing impairment scores. No significant differences among the predictive abilities of the impairment calculations were evident; however, the average binaural impairment assigned differed significantly among the six calculations examined. Individuals who demonstrated 0% impairment had significantly lower (i.e., better HHIA/E scores compared to those with non-zero impairment for each formula. These results supported the idea that audiometric data provided an insufficient explanation for real-world hearing difficulties.
NEW METHOD TO MEASURE PISTON SKIRT DIMENSIONS
Institute of Scientific and Technical Information of China (English)
Qin Yuexia; Hu Dejin
2004-01-01
The measurement of the middle-convex and varying ellipse profile of a piston skirt is a key technology because of its complex profile and high precision. Generally, a piston is measured on special device after it is machined. High accuracy can be achieved through this off-line measurement, but the result diverges from the actual dimension. Therefore, a no-contact in-site measurement system is proposed. A laser displacement meter is used to measure the profile of the piston skirt. A computer connected to the meter is used to process the measured data. A regression analysis method is used to process the ellipse section data. The method of moving average is used to process the middle-convex curve data. By using the given system, high measurement accuracy can be gained, and the production requirement is met.
CALCULATION OF THE UNSTEADY WATER LINE IN THE KRASNODAR SUBURBAN CHANNEL FOR WATER MEASUREMENT
Directory of Open Access Journals (Sweden)
Ivanenko Y. G.
2015-12-01
Full Text Available Low level of water accounting and poor control in water distribution in the irrigation system are the main negative factors of industrial influence on irrigated natural complexes. Complex ecosystem way to control water resources involves qualitative improvement and optimization of all parts and elements of irrigation system, from the headwater pool, main channels to local water distribution channels. In this regard, when engineering, constructing, using some new and reconstructed old irrigated systems, the most important problems are the optimization of water use from natural water resources, development and use of highly efficient water-saving and energy-saving technologies of water distribution and water use in the irrigation system. The problem of economical and efficient consumption of water resources on the studied water complex cannot be solved successfully without any related consideration of water accounting and water consumption questions based on system principles. System principles are supposed to collect, analyze and use the information, with the help of complex technical means, which are used for water measurement in conditions of water charges, and for the purpose to control the technological processes of water supply and water drainage, when the needs of water users are satisfied and the environment get less damage. In the work, we study the mathematical calculation of the unsteady water line in the Krasnodar suburban channel for water measurement. The imitated research of hydraulic processes were carried out on the mathematical model of water measurement, based on the characteristic methods, with the use of analytical solution of ordinary differential equations of the initial characteristics. The use of the considered method of water measurement in irrigation channels with the use of analytical solution of ordinary differential equations of initial characteristics will allow to optimize the processes of water measurement and to
A method to measure the axion mass
Carboni, G.
1981-05-01
We have calculated the decay rate of the triplet state of positronium into axion + gamma, under the hypothesis that the axion mass is less than 1 MeV. The branching ratio is found to be ~3 × 10-8. We describe a possible experiment that could detect the axion and measure its mass. On leave from Istituto Nazionale di Fisica Nuclear, Sezione di Pisa, Pisa, Italy.
Alhassid, Y; Liu, S; Mukherjee, A; Nakada, H
2014-01-01
The shell model Monte Carlo (SMMC) method enables calculations in model spaces that are many orders of magnitude larger than those that can be treated by conventional methods, and is particularly suitable for the calculation of level densities in the presence of correlations. We review recent advances and applications of SMMC for the microscopic calculation of level densities. Recent developments include (i) a method to calculate accurately the ground-state energy of an odd-mass nucleus, circumventing a sign problem that originates in the projection on an odd number of particles, and (ii) a method to calculate directly level densities, which, unlike state densities, do not include the spin degeneracy of the levels. We calculated the level densities of a family of nickel isotopes $^{59-64}$Ni and of a heavy deformed rare-earth nucleus $^{162}$Dy and found them to be in close agreement with various experimental data sets.
Contemporary methods of body composition measurement.
Fosbøl, Marie Ø; Zerahn, Bo
2015-03-01
Reliable and valid body composition assessment is important in both clinical and research settings. A multitude of methods and techniques for body composition measurement exist, all with inherent problems, whether in measurement methodology or in the assumptions upon which they are based. This review is focused on currently applied methods for in vivo measurement of body composition, including densitometry, bioimpedance analysis, dual-energy X-ray absorptiometry, computed tomography (CT), magnetic resonance techniques and anthropometry. Multicompartment models including quantification of trace elements by in vivo neutron activation analysis, which are regarded as gold standard methods, are also summarized. The choice of a specific method or combination of methods for a particular study depends on various considerations including accuracy, precision, subject acceptability, convenience, cost and radiation exposure. The relative advantages and disadvantages of each method are discussed with these considerations in mind. PMID:24735332
A NUMERICAL CALCULATION METHOD FOR EIGENVALUE PROBLEMS OF NONLINEAR INTERNAL WAVES
Institute of Scientific and Technical Information of China (English)
SHI Xin-gang; FAN Zhi-song; LIU Hai-long
2009-01-01
Generally speaking, the background shear current U(z)must be taken into account in eigenvalue problems of nonlinear internal waves in ocean, as is different from those of linear internal waves. A numerical calculation method for eigenvalue problems of nonlinear internal waves is presented in this paper on the basis of the Thompson-Haskell's calculation method. As an application of this method, at a station (21°N, 117°15′E) in the South China Sea, a modal structure and parameters of nonlinear internal waves are calculated, and the results closely agree with the calculated results based on observation by Yang et al..
Ebru Ermis, Elif; Celiktas, Cuneyt
2015-07-01
Calculations of gamma-ray mass attenuation coefficients of various detector materials (crystals) were carried out by means of FLUKA Monte Carlo (MC) method at different gamma-ray energies. NaI, PVT, GSO, GaAs and CdWO4 detector materials were chosen in the calculations. Calculated coefficients were also compared with the National Institute of Standards and Technology (NIST) values. Obtained results through this method were highly in accordance with those of the NIST values. It was concluded from the study that FLUKA MC method can be an alternative way to calculate the gamma-ray mass attenuation coefficients of the detector materials.
Calculation of renal depth by conjugate-view method using dual-head gamma camera
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyun Mi; Suh, Tae Suk; Choe, Bo Young; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo; Lee, Hyoung Koo [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of)
2001-12-01
In this study, we developed a new method for the determination of renal depth with anterior and posterior renal scintigrams in a dual-head gamma camera, considering the attenuation factor e{sup -{mu}}{sup x} of the conjugate-view method. We developed abdomen and kidney phantoms to perform experiments using Technetium-99m dimercaptosuccinic acid ({sup 99m}Tc-DMSA). The phantom images were obtained by dual-head gamma camera equipped with low-energy, high-resolution, parallel-hole collimators (ICONf, Siemens). The equation was derived from the linear integration of emission {gamma}-ray considering attenuation from the posterior abdomen to the anterior abdomen phantom surface. The program for measurement was developed by Microsoft Visual C++ 6.0. Renal depths of the phantoms were derived from the derived equations and compared with the exact geometrical values. Differences between the measured and the calculated values were the range of 0.1 to 0.7 cm (0.029{+-} 0.15 cm, mean {+-}S. D.). The present study showed that the use of the derived equations for renal depth measurement, combined with quantitative planar imaging using duel-head gamma camera, could provide more accurate results for individual variation than the conventional method.
A New Method for Setting Calculation Sequence of Directional Relay Protection in Multi-Loop Networks
Haijun, Xiong; Qi, Zhang
2016-08-01
Workload of relay protection setting calculation in multi-loop networks may be reduced effectively by optimization setting calculation sequences. A new method of setting calculation sequences of directional distance relay protection in multi-loop networks based on minimum broken nodes cost vector (MBNCV) was proposed to solve the problem experienced in current methods. Existing methods based on minimum breakpoint set (MBPS) lead to more break edges when untying the loops in dependent relationships of relays leading to possibly more iterative calculation workloads in setting calculations. A model driven approach based on behavior trees (BT) was presented to improve adaptability of similar problems. After extending the BT model by adding real-time system characters, timed BT was derived and the dependency relationship in multi-loop networks was then modeled. The model was translated into communication sequence process (CSP) models and an optimization setting calculation sequence in multi-loop networks was finally calculated by tools. A 5-nodes multi-loop network was applied as an example to demonstrate effectiveness of the modeling and calculation method. Several examples were then calculated with results indicating the method effectively reduces the number of forced broken edges for protection setting calculation in multi-loop networks.
International Nuclear Information System (INIS)
This report summarizes the procedure used to calculate the uncertainties associated to environmental radioactivity measurements, focusing on those obtained by radiochemical separation in which tracers have been added. Uncertainties linked to activity concentration calculations, isotopic rat iso, inventories, sequential leaching data, chronology dating by using C.R.S. model and duplicate analysis are described in detail. The objective of this article is to serve as a guide to people not familiarized with this kind of calculations, showing clear practical examples. The input of the formulas and all the data needed to achieve these calculations into the Lotus 1, 2, 3 WTN is outlined as well. (Author) 13 refs
International Nuclear Information System (INIS)
This report summarizes the procedure used to calculate the uncertainties associated to environmental radioactivity measurements. focusing on those obtained by radiochemical separation in which tracers have been added. Uncertainties linked to activity concentration calculations, isotopic ratio, inventories, sequential leaching data, chronology dating by using C.R.S model and duplicate analysis are described in detail. The objective of this article is to serve as a guide to people not familiarized with this kind of calculations, showing clear practical examples. The input of the formulas and all the data needed to achieve these calculations into the Lotus 1,2,3, WIN is outlined as well. (Author)
Institute of Scientific and Technical Information of China (English)
张顺
2012-01-01
VaR自上个世纪90年代起,已经成为了主流的度量风险的方式,但是,VaR模型的计算方式有十多种,哪一种VaR模型是最优模型,甚至于构建什么样的比较框架才能选择出最优模型,仍然没有一个统一的标准。采取比较主流的方式对VaR在股票中的计算以及对VaR模型的回测,是呈现VaR作为现阶段最为流行的风险度量工具的计算和回测检验的方式。%since the 1990s of the last century,VaR has become a mainstream way to measure risk,but there are dozens of calculation methods of VaR model.There is no unified standard as for what kind of VaR model is the best one and what comparative framework can help to select the best model.To take a more mainstream way to calculate the VaR in stock and backtest VaR model is very useful.
A New Optimization Method for Centrifugal Compressors Based on 1D Calculations and Analyses
Pei-Yuan Li; Chu-Wei Gu; Yin Song
2015-01-01
This paper presents an optimization design method for centrifugal compressors based on one-dimensional calculations and analyses. It consists of two parts: (1) centrifugal compressor geometry optimization based on one-dimensional calculations and (2) matching optimization of the vaned diffuser with an impeller based on the required throat area. A low pressure stage centrifugal compressor in a MW level gas turbine is optimized by this method. One-dimensional calculation results show that D3/D...
An effective method to accurately calculate the phase space factors for $\\beta^- \\beta^-$ decay
Neacsu, Andrei
2015-01-01
Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates, and for the analysis of the associated electron angular and energy distributions. We present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.
Logarithmic derivative method and system for capacitance measurement
Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao
2015-08-01
A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10-8 s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes.
Energy Technology Data Exchange (ETDEWEB)
Maita, S.; Nakashima, A.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan)
1998-09-04
Based on a simple surface panel method named SQCM, we develop a method to calculate nonlinear cavity on 2-D wing by introducing the four kinds of cavity models, i.e. closed model, semi-closed model, open model and supercavitating model. This method gives pressure distribution, lift and drag of the wing. Then, by combining the QCM program, the concept of the equivalent 2-D wing and the present cavity calculation method, we obtain the characteristics of two cavitating propellers. Comparisons between calculated results and experimental ones confirm the usefulness of our method. 11 refs., 15 figs., 1 tab.
A quantitative measurement method for comparison of seated postures.
Hillman, Susan J; Hollington, James
2016-05-01
This technical note proposes a method to measure and compare seated postures. The three-dimensional locations of palpable anatomical landmarks corresponding to the anterior superior iliac spines, clavicular notch, head, shoulders and knees are measured in terms of x, y and z co-ordinates in the reference system of the measuring apparatus. These co-ordinates are then transformed onto a body-based axis system which allows comparison within-subject. The method was tested on eleven unimpaired adult participants and the resulting data used to calculate a Least Significant Difference (LSD) for the measure, which is used to determine whether two postures are significantly different from one another. The method was found to be sensitive to the four following standardised static postural perturbations: posterior pelvic tilt, pelvic obliquity, pelvic rotation, and abduction of the thighs. The resulting data could be used as an outcome measure for the postural alignment aspect of seating interventions in wheelchairs. PMID:26920073
Hubbell rectangular source integral calculation using a fast Chebyshev wavelets method.
Manai, K; Belkadhi, K
2016-07-01
An integration method based on Chebyshev wavelets is presented and used to calculate the Hubbell rectangular source integral. A study of the convergence and the accuracy of the method was carried out by comparing it to previous studies. PMID:27152913
Survey of emissivity measurement by radiometric methods.
Honner, M; Honnerová, P
2015-02-01
A survey of the state of the art in the field of spectral directional emissivity measurements by using radiometric methods is presented. Individual quantity types such as spectral, band, or total emissivity are defined. Principles of emissivity measurement by various methods (direct and indirect, and calorimetric and radiometric) are discussed. The paper is focused on direct radiometric methods. An overview of experimental setups is provided, including the design of individual parts such as the applied reference sources of radiation, systems of sample clamping and heating, detection systems, methods for the determination of surface temperature, and procedures for emissivity evaluation.
Survey of emissivity measurement by radiometric methods.
Honner, M; Honnerová, P
2015-02-01
A survey of the state of the art in the field of spectral directional emissivity measurements by using radiometric methods is presented. Individual quantity types such as spectral, band, or total emissivity are defined. Principles of emissivity measurement by various methods (direct and indirect, and calorimetric and radiometric) are discussed. The paper is focused on direct radiometric methods. An overview of experimental setups is provided, including the design of individual parts such as the applied reference sources of radiation, systems of sample clamping and heating, detection systems, methods for the determination of surface temperature, and procedures for emissivity evaluation. PMID:25967774
A hybrid Monte Carlo and response matrix Monte Carlo method in criticality calculation
International Nuclear Information System (INIS)
Full core calculations are very useful and important in reactor physics analysis, especially in computing the full core power distributions, optimizing the refueling strategies and analyzing the depletion of fuels. To reduce the computing time and accelerate the convergence, a method named Response Matrix Monte Carlo (RMMC) method based on analog Monte Carlo simulation was used to calculate the fixed source neutron transport problems in repeated structures. To make more accurate calculations, we put forward the RMMC method based on non-analog Monte Carlo simulation and investigate the way to use RMMC method in criticality calculations. Then a new hybrid RMMC and MC (RMMC+MC) method is put forward to solve the criticality problems with combined repeated and flexible geometries. This new RMMC+MC method, having the advantages of both MC method and RMMC method, can not only increase the efficiency of calculations, also simulate more complex geometries rather than repeated structures. Several 1-D numerical problems are constructed to test the new RMMC and RMMC+MC method. The results show that RMMC method and RMMC+MC method can efficiently reduce the computing time and variations in the calculations. Finally, the future research directions are mentioned and discussed at the end of this paper to make RMMC method and RMMC+MC method more powerful. (authors)
THE COST CALCULATION AND ANALYSIS BY MEANS OF THE STANDARD COST METHOD
Directory of Open Access Journals (Sweden)
ADRIANA MONICAŢEGLEDI
2014-05-01
Full Text Available Originally known as the Estimated Cost System, it has evolved, nowadays being called Standard Cost Accounting. Standard cost calculation method is based on scheduled cost, pre-calculated, set before the start of the manufacturing process itself. This method allows the determination of the elements that influence the amount of costs and their deviations from the predetermined costs.
Method of Time-Delay Calculating and Correcting to Control Spin-Stabilized Satellite Synchronously
Institute of Scientific and Technical Information of China (English)
YangTianshe; LiJisheng; HuangYongxuan
2005-01-01
The key to control Spin-Stabilized Satellites Synchronously is to determine the models for calculating and correcting of time-delay at the different situations. Based on the principle of Synchronous-Control mode, the methods of determining the models of calculating and correcting of time-delay are proposed. The methods have been proved to be effective in real satellite control engineering.
Smit, W.M.A.; Bode, J.H.G.; Straten, A.J. van
1979-01-01
A general method for the calculation of absolute rotational corrections for the dipole moment derivatives is given based on the definition of pure geometrical distortions. The method is generally valid and allows the rotational contributions to be calculated for all modes of any molecule. The relati
International Nuclear Information System (INIS)
Due to secondary cosmic radiation (SCR), pilots and flight attendants receive elevated effective doses at flight altitudes. For this reason, since 2003 aircrew members are considered as occupationally exposed, in Germany. This work deals with the calculation of dose conversion coefficients (DCC) for protons, neutrons, electrons, positrons, photons and myons, which are crucial for estimation of effective dose from SCR. For the first time, calculations were performed combining Geant4 - a Monte Carlo code developed at CERN - with the voxel phantoms for the reference female and male published in 2008 by ICRP and ICRU. Furthermore, measurements of neutron fluence spectra - which contribute the major part to the effective dose of SCR - were carried out at the Environmental Research Station Schneefernerhaus (UFS) located at 2650 m above sea level nearby the Zugspitze mountain, Germany. These measured neutron spectra, and additionally available calculated spectra, were then folded with the DCC calculated in this work, and effective dose rates for different heights were calculated.
Radioactivity calculation and measurement of spent fuel elements of SPRR-300
International Nuclear Information System (INIS)
As one of the original preparation works of SPRR-300 decommissioning, radioactivity of spent fuel elements in the reactor should be estimated by both calculation and experiment. ORIGEN2 is chosen to do the calculation. The ACCESS database of reactor operation history is built, whose tables is connected by load ID. The needed input history data is obtained using inquiries. Assistant programs, such as Operation Data Processing Program, Composition Data Processing Program, etc. are developed to change the original data into ORIGEN2 input file. In the output file, there are nuclides data, gamma activity data, and so on. Gamma spectrum of three elements in three distances is measured. radioactivity of three nuclides measured is compared to that calculated. The two kinds of data are at the same order. So the data calculated are believable. The comparison shows that the data calculated are reliable. (authors)
Jackin, Boaz Jessie; Miyata, Hiroaki; Ohkawa, Takeshi; Ootsu, Kanemitsu; Yokota, Takashi; Hayasaki, Yoshio; Yatagai, Toyohiko; Baba, Takanobu
2014-12-15
A method has been proposed to reduce the communication overhead in computer-generated hologram (CGH) calculations on parallel and distributed computing devices. The method uses the shifting property of Fourier transform to decompose calculations, thereby avoiding data dependency and communication. This enables the full potential of parallel and distributed computing devices. The proposed method is verified by simulation and optical experiments and can achieve a 20 times speed improvement compared to conventional methods, while using large data sizes.
Stiffeners in variational-difference method for calculating shells with complex geometry
Ivanov Vyacheslav Nikolaevich; Kushnarenko Ivan Valer'evich
2014-01-01
We have already considered an introduction of reinforcements in the variational-difference method (VDM) of shells analysis with complex shape. At the moment only ribbed shells of revolution and shallow shells can be calculated with the help of developed analytical and finite-difference methods. Ribbed shells of arbitrary shape can be calculated only using the finite element method (FEM). However there are problems, when using FEM, which are absent in finite- and variational-difference methods...
DEFF Research Database (Denmark)
Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug
2014-01-01
Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed.......Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed....
A Simple Method for Measuring Tensile Force with Piezoelectric Patch
Institute of Scientific and Technical Information of China (English)
ZHANG Zhi-Wen; JIANG Zhong-Wei; Testuya Morisaki
2007-01-01
@@ We propose a simple method for monitoring the axial tensile and compressive force in a structure by using a piezoelectric patch with the piezoelectric impedance based measurement. A simple approximate equation for estimating the tensile force in two different conditions, which can be calculated easily if the natural frequencies in two different states are measured, is explained in detail. On another front, the natural frequency can be very easily measured by a piezoelectric element by bonding it on the measuring subject structure, because its electric impedance of piezoelement is related to the structural mechanical impedance. Furthermore, an experiment for measuring a tensile force in a simple supported beam is carried out for validating the proposed method. The results show a good accuracy in estimating the tensile force variation by the natural frequency change measured from the piezoelement.
International Nuclear Information System (INIS)
As an effort to achieve efficient yet accurate transport transient calculations for power reactors, the conditional transport update scheme in method of characteristics (MOC) based coarse mesh finite difference (CMFD) transient calculation is developed. In this scheme, the transport calculations serves as an online group constant generator for the 3-D CMFD transient calculation and the solution of 3-D transient problem is mainly obtained from the 3-D CMFD transient calculation. In order to reduce the computational burden of the intensive transport calculation, the transport updates is conditionally performed by monitoring change of composition and core condition. This efficient transient transport method is applied to 3x3 assembly rod ejection problem to examine the effectiveness and accuracy of the conditional transport calculation scheme. (author)
Stathopoulos, N A; Savaidis, S P; Botsialas, A; Ioannidis, Z C; Georgiadou, D G; Vasilopoulou, M; Pagiatakis, G
2015-02-20
A generalized transmission line method (TLM) that provides reflection and transmission calculations for a multilayer dielectric structure with coherent, partial coherent, and incoherent layers is presented. The method is deployed on two different application fields. The first application of the method concerns the thickness measurement of the individual layers of an organic light-emitting diode. By using a fitting approach between experimental spectral reflectance measurements and the corresponding TLM calculations, it is shown that the thickness of the films can be estimated. The second application of the TLM concerns the calculation of the external quantum efficiency of an organic photovoltaic with partially coherent rough interfaces between the layers. Numerical results regarding the short circuit photocurrent for different layer thicknesses and rough interfaces are provided and the performance impact of the rough interface is discussed in detail. PMID:25968218
Efficient calculation method for realistic deep 3D scene hologram using orthographic projection
Igarashi, Shunsuke; Nakamura, Tomoya; Matsushima, Kyoji; Yamaguchi, Masahiro
2016-03-01
We propose a fast calculation method to synthesize a computer-generated hologram (CGH) of realistic deep three-dimensional (3D) scene. In our previous study, we have proposed a calculation method of CGH for reproducing such scene called ray-sampling-plane (RSP) method, in which light-ray information of a scene is converted to wavefront, and the wavefront is numerically propagated based on diffraction theory. In this paper, we introduce orthographic projection to the RSP method for accelerating calculation time. By numerical experiments, we verified the accelerated calculation with the ratio of 28-times compared to the conventional RSP method. The calculated CGH was fabricated by the printing system using laser lithography and demonstrated deep 3D image reconstruction in 52mm×52mm with realistic appearance effect such as gloss and translucent effect.
Institute of Scientific and Technical Information of China (English)
张文娟; 黄守道; 高剑; CHEN; Zhe
2013-01-01
An analytic electromagnetic calculation method for doubly fed induction generator(DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed. The electromagnetic calculation of DFIG was divided into three steps: the magnetic flux calculation, parameters derivation and performance checks. For each step, the detailed numeric calculation formulas were all derived. Combining the calculation formulas, the whole electromagnetic calculation procedure was established, which consisted of three iterative calculation loops, including magnetic saturation coefficient, electromotive force and total output power. All of the electromagnetic and performance data of DIFG can be calculated conveniently by the established calculation procedure, which can be used to evaluate the new designed machine. A 1.5 MW DFIG designed by the proposed procedure was built, for which the whole type tests including no-load test, load test and temperature rising test were carried out. The test results have shown that the DFIG satisfies technical requirements and the test data fit well with the calculation results which prove the correctness of the presented calculation method.
Energy Technology Data Exchange (ETDEWEB)
NONE
2002-05-01
A working group driven by Electricite de France (EdF), Chauffage Fioul and Gaz de France (GdF) companies has been built with the sustain of several building engineering companies in order to clarify the use of the method of calculation of the global energy cost of buildings. This global cost is an economical decision help criterion among others. This press kit presents, first, the content of the method (input data, calculation of annual expenses, calculation of the global energy cost, display of results and limitations of the method). Then it fully describes the method and its appendixes necessary for its implementation: economical and financial context, general data of the project in progress, environmental data, occupation and comfort level, variants, investment cost of energy systems, investment cost for the structure linked with the energy system, investment cost for other invariant elements of the structure, calculation of consumptions (space heating, hot water, ventilation), maintenance costs (energy systems, structure), operation and exploitation costs, tariffs and consumption costs and taxes, actualized global cost, annualized global cost, comparison between variants. The method is applied to a council building of 23 flats taken as an example. (J.S.)
New ITF measure method based on fringes
Fang, Qiaoran; Liu, Shijie; Gao, Wanrong; Zhou, You; Liu, HuanHuan
2016-01-01
With the unprecedented developments of the intense laser and aerospace projects', the interferometer is widely used in detecting middle frequency indicators of the optical elements, which put forward very high request towards the interferometer system transfer function (ITF). Conventionally, the ITF is measured by comparing the power spectra of known phase objects such as high-quality phase step. However, the fabrication of phase step is complex and high-cost, especially in the measurement of large-aperture interferometer. In this paper, a new fringe method is proposed to measure the ITF without additional objects. The frequency was changed by adjusting the number of fringes, and the normalized transfer function value was measured at different frequencies. The ITF value measured by fringe method was consistent with the traditional phase step method, which confirms the feasibility of proposed method. Moreover, the measurement error caused by defocus was analyzed. The proposed method does not require the preparation of a step artifact, which greatly reduces the test cost, and is of great significance to the ITF measurement of large aperture interferometer.
A new method for angular displacement measurement
Institute of Scientific and Technical Information of China (English)
Caini Zhang(张彩妮); Xiangzhao Wang(王向朝)
2003-01-01
We describe a new method for angular displacement measurements that is based on a Fabry-Perot inter-ferometer. A measurement accuracy of 10-s rad is obtained by use of the sinusoidal phase modulatinginterferometry. Another Fabry-Perot interferometer is used to obtain the key initial angle of incidence.
A Discussion about Reducing the Amount of Calculation of Direct Method
Institute of Scientific and Technical Information of China (English)
DUTai-sheng; XIAOZe-chang
2003-01-01
The general interpolation mentioned in this article provides an effective way for reducing the amount of calculation of direct optimal exploration. It has been testified by real case calculations that the interpolation is not only reliable but also can save the amount of calculation by nearly 36 %. Large amount of calculation and lacking strict theoretical basis has been the two disadvantage of direct method by new. If this defect is not overcome, they will not only seriously affect the application of this meth-od, but also hinder its further research. Based on sufficient calculation practice, this article has made a primary discussion about the theory and method of reducing the amount of calculation, and has achieved some satisfactory results.
Novotný, O; Bernhardt, D; Grieser, M; Hahn, M; Krantz, C; Lestinsky, M; Müller, A; Repnow, R; Schippers, S; Wolf, A; Savin, D W
2012-01-01
We have measured electron-ion recombination for Fe XII forming Fe XI using a merged beams configuration at the heavy-ion storage ring TSR located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The measured merged beams recombination rate coefficient (MBRRC) for collision energies from 0 to 1500 eV is presented. This work uses a new method for determining the absolute MBRRC based on a comparison of the ion beam decay rate with and without the electron beam on. For energies below 75 eV, the spectrum is dominated by dielectronic recombination (DR) resonances associated with 3s-3p and 3p-3d core excitations. At higher energies we observe contributions from 3-N' and 2-N' core excitations DR. We compare our experimental results to state-of-the-art multi-configuration Breit-Pauli (MCBP) calculations and find significant differences, both in resonance energies and strengths. We have extracted the DR contributions from the measured MBRRC data and transformed them into a plasma recombination ra...
Energy Technology Data Exchange (ETDEWEB)
Zakrzewski, K. [Technical Univ. of Lodz (Poland). Inst. of Electrical Machines and Transformers; Tomczuk, B. [Technical Univ. of Opole (Poland). Dept. of Electrical Engineering and Automatic Control
1996-05-01
This paper presents 3-D integral approach to the magnetic field and inductance calculations. A minimization of the kernel norm has been carried out for the integral equation governing the field. The software package TRACAL3, based on the integral methods for field and inductance calculations, has been developed and implemented for personal computers. The application of the 3-D mathematical models has been made for the leakage field in a current transformer. The results of calculations were compared with the measured ones. The comparison yields good agreement. Thus, the worked out software package seems to be one of the CAD tools.
Monte Carlo simulation in the reaction rate's calculation with neutron-activation method
International Nuclear Information System (INIS)
With MCNP/4B code, the influence of cut-off energy, flux tallies, nuclear databases and perturbation on the reaction rate's calculation with neutron-activation method are analysed. When the effective reaction threshold is chosen as the cut-off energy, calculation time is considerably reduced and yet the results are not changed. Comparing calculations with cell tallies (F4) with those performed with detector tallies (F5), the counting efficiency of cell tallies is higher and the results are slightly higher, but still credible. With different nuclear databases, calculated results can be different. The perturbation among the detectors doesn't effect on the calculated results. (authors)
Zhao, Yu; Piao, Mei-lan; Li, Gang; Kim, Nam
2015-07-01
Fast calculation method for a computer-generated cylindrical hologram (CGCH) is proposed. The method consists of two steps: the first step is a calculation of a virtual wave-front recording surface (WRS), which is located between the 3D object and CGCH. In the second step, in order to obtain a CGCH, we execute the diffraction calculation based on the fast Fourier transform (FFT) from the WRS to the CGCH, which are in the same concentric arrangement. The computational complexity is dramatically reduced in comparison with direct integration method. The simulation results confirm that our proposed method is able to improve the computational speed of CGCH.
Volumic activities measurements and equivalent doses calculation of indoor 222Rn in Morocco
Directory of Open Access Journals (Sweden)
Abdelmajid Choukri
2015-09-01
Full Text Available Purpose: As a way of prevention, we have measured the volumic activities of indoor 222Rn and we have calculated the corresponding effective dose in some dwellings and enclosed areas in Morocco. Seasonal variation of Radon activities and Relationships between variation of these activities and some parameters such height, depth and type of construction were also established in this work.Methods: The passive time-integrated method of using a solid state nuclear track detector (LR-115 type II was employed. These films, cut in pieces of 3.4 ´ 2.5 cm2, were placed in detector holders and enclosed in heat-scaled polyethylene bags.Results: The measured volumic activities of radon vary in houses, between 31 and 136 Bq/m3 (0.55 and 2.39 mSv/year with an average value of 80 Bq/m3 (1.41 mSv/year. In enclosed work area, they vary between 60 Bq/m3 (0.38 mSv/year in an ordinary area to 1884 Bq/m3 (11.9 mSv/year at not airy underground level of 12 m. the relatively higher volumic activities of 222Rn in houses were measured in Youssoufia and khouribga towns situated in regions rich in phosphate deposits. Measurements at the geophysical observatory of Berchid show that the volumic activity of radon increases with depth, this is most probably due to decreased ventilation. Conclusion: The obtained results show that the effective dose calculated for indoor dwellings are comparable to those obtained in other regions in the word. The risks related to the volumic activities of indoor radon could be avoided by simple precautions such the continuous ventilation. The reached high value of above 1884 Bq/m3 don't present any risk for workers health in the geophysical observatory of Berchid because workers spend only a few minutes by day in the cellar to control and reregister data.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Constructing a weighting soil layer at the downstream toe of dike on layered ground is an effective measure to prevent the foundation from blowout failures. In this paper, a series of differential equations describing the seepage flow in layered dike foundation were established, and a united method combining analytic method with one-dimensional finite difference method was proposed for solving the equations. The case study shows that the results calculated by the united method are considerably identical to the computational results of Finite Element Method (FEM), and the united method is very simple and easy compared to the FEM.
MEASUREMENT OF ADHESION FORCES IN AIR WITH THE VIBRATION METHOD
Institute of Scientific and Technical Information of China (English)
Siegfried; Ripperger; Konrad; Hein
2005-01-01
The vibration method represents a practical method for the measurement of adhesion forces and adhesion force distributions. This method causes sinusoidally altemating stresses and yields detachment and contact forces between particles and substrate of the same order of magnitude. Alternating contact forces of the vibration method can cause an adhesion force intensification through flattening of asperities. The measuring principle of the vibration method and the analysis of experimental results are described in the article. Normal adhesion forces (pull-off forces) are measured using the vibration method and the colloidal probe technique. The results of both methods show good agreement for small particle sizes. The influence of the detachment force direction is shown by comparing tangential and normal adhesion forces measured using particle reentrainment in a turbulent air flow and the vibration method, respectively. The surface roughness of the substrate and the relative humidity are shown to significantly influence the measured adhesion forces. For the calculation of the adhesion forces, an approach by Rabinovich was combined with approximations of plastic micro asperity flattening. The Rabinovich approach accounts for roughness effects on the van der Waals force by incorporating the rms roughness of the interacting surfaces. rms-values of the particles and substrates were measured with atomic force microscopy at different scanning areas.
COMPANY PERFORMANCE MEASUREMENT AND REPORTING METHODS
Directory of Open Access Journals (Sweden)
Nicu Ioana Elena
2012-12-01
Full Text Available One of the priorities of economic research has been and remains the re-evaluation of the notion of performance and especially exploring and finding some indicators that would reflect as accurately as possible the subtleties of the economic entity. The main purpose of this paper is to highlight the main company performance measurement and reporting methods. Performance is a concept that raises many question marks concerning the most accurate or the best method of reporting the performance at the company level. The research methodology has aimed at studying the Romanian and foreign specialized literature dealing with the analyzed field, studying magazines specialized on company performance measurement. If the financial performance measurement indicators are considered to offer an accurate image of the situation of the company, the modern approach through non-financial indicators offers a new perspective upon performance measurement, which is based on simplicity. In conclusion, after the theoretical study, I have noticed that the methods of performance measurement, reporting and interpretation are various, the opinions regarding the best performance measurement methods are contradictive and the companies prefer resorting to financial indicators that still play a more important role in the consolidation of the company performance measurement than the non-financial indicators do.
Calculation of the detection limit in radiation measurements with systematic uncertainties
Energy Technology Data Exchange (ETDEWEB)
Kirkpatrick, J.M., E-mail: john.kirkpatrick@canberra.com; Russ, W.; Venkataraman, R.; Young, B.M.
2015-06-01
The detection limit (L{sub D}) or Minimum Detectable Activity (MDA) is an a priori evaluation of assay sensitivity intended to quantify the suitability of an instrument or measurement arrangement for the needs of a given application. Traditional approaches as pioneered by Currie rely on Gaussian approximations to yield simple, closed-form solutions, and neglect the effects of systematic uncertainties in the instrument calibration. These approximations are applicable over a wide range of applications, but are of limited use in low-count applications, when high confidence values are required, or when systematic uncertainties are significant. One proposed modification to the Currie formulation attempts account for systematic uncertainties within a Gaussian framework. We have previously shown that this approach results in an approximation formula that works best only for small values of the relative systematic uncertainty, for which the modification of Currie's method is the least necessary, and that it significantly overestimates the detection limit or gives infinite or otherwise non-physical results for larger systematic uncertainties where such a correction would be the most useful. We have developed an alternative approach for calculating detection limits based on realistic statistical modeling of the counting distributions which accurately represents statistical and systematic uncertainties. Instead of a closed form solution, numerical and iterative methods are used to evaluate the result. Accurate detection limits can be obtained by this method for the general case.
Apparatus and method for measuring viscosity
Murphy, Jr., Robert J.
1986-01-01
The present invention is directed to an apparatus and method for measuring the viscosity of a fluid. This apparatus and method is particularly useful for the measurement of the viscosity of a liquid in a harsh environment characterized by high temperature and the presence of corrosive or deleterious gases and vapors which adversely affect conventional ball or roller bearings. The apparatus and method of the present invention employ one or more flexural or torsional bearings to suspend a bob capable of limited angular motion within a rotatable sleeve suspended from a stationary frame.
Data Fusion Method for Manufacturing Measurement
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
A data fusion method of online multisensors is prop os ed in this paper based on artificial neuron. First, the dynamic data fusion mode l on artificial neuron is built. Then the calibration of data fusion is discusse d with self-adaptive weighing technique. Finally performance of the method is d emonstrated by an online vibration measurement case. The results show that the f used data are more stable, sensitive, accurate, reliable than that of single sen sor data.Data Fusion Method for Manufacturing Measure...
A new method of constructing measure
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
By using a well known result in combinatorics, named K(o)nig Lemma, this paper generalized the method of constructing measure by repeated subdivision, which was a basic tool for fractal geometry. A more general method was presented to construct measure, which was an essential improvement to the existing result. The proof employed a skill similar to that for K(o)nig Lemma, which helped to avoid using the compactness in Euclidean space. Two conditions of the existing method were found not necessary.
Torsion method for measuring piezooptic coefficients
Energy Technology Data Exchange (ETDEWEB)
Skab, I.; Smaga, I.; Savaryn, V.; Vasylkiv, Yu.; Vlokh, R. [Institute of Physical Optics, Lviv (Ukraine)
2011-01-15
We develop and describe analytically a torsion method for measuring piezooptic coefficients associated with shear stresses. It is shown that the method enables to increase significantly the accuracy of determination of piezooptic coefficients. The method and the appropriate apparatus are verified experimentally on the example of LiNbO{sub 3} crystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
New methods of measuring normal acoustic impedance
Wayman, James L.
1984-01-01
In recent years new methods based on signal processing technical have been developed to measure the normal acoustic impedance of materials. These methods proved to be considerably faster easier to implement than the SRW method rhey replace. Mathematical, hardware and software aspects of these techniques are discussed and results obtained over a frequency range of 200-4000 Hz for several architectural materials are presented. NPS Foundation Research Program http://archive....
Mendizabal, A.; González-Díaz, J. B.; San Sebastián, M.; Echeverría, A.
2016-07-01
This paper describes the implementation of a simple strategy adopted for the inherent shrinkage method (ISM) to predict welding-induced distortion. This strategy not only makes it possible for the ISM to reach accuracy levels similar to the detailed transient analysis method (considered the most reliable technique for calculating welding distortion) but also significantly reduces the time required for these types of calculations. This strategy is based on the sequential activation of welding blocks to account for welding direction and transient movement of the heat source. As a result, a significant improvement in distortion prediction is achieved. This is demonstrated by experimentally measuring and numerically analyzing distortions in two case studies: a vane segment subassembly of an aero-engine, represented with 3D-solid elements, and a car body component, represented with 3D-shell elements. The proposed strategy proves to be a good alternative for quickly estimating the correct behaviors of large welded components and may have important practical applications in the manufacturing industry.
Xie, Hang; Sha, Wei E I
2015-01-01
Numerical methods are developed in the quantum transport calculations for electron in the waveguides with spin-orbital (Rashba) interaction. The methods are based on a hybrid mode-matching scheme in which the wavefunctions are expressed as the superposition of eigenmodes in the lead regions and in the device region the wavefunction is expressed on the discrete basis. Two versions are presented for the lead without and with the Rashba interaction. In the latter case the eigenmodes are obtained from a quadratic eigenproblem calculation. These methods are suitable for the systems with variable geometries or arbitrary potential profiles. The computation can be effectively accelerated by the sparse matrix technique. We also investigate the Fano-Rashba bound states in the Rashba waveguides by some nonlinear eigenstate calculation. This calculation is based on a mode-matching method and self-consistent results are obtained in our calculations.
Directory of Open Access Journals (Sweden)
Starishko Ivan Nikolaevich
2014-03-01
Full Text Available The proposed calculation method is specific in terms of determining the carrying capacity of eccentrically compressed concrete elements, in contrast to the calculation by error method, as in the existing regulations, where in the result of the calculation is not known what is the limit load the eccentric compression element can withstand. The proposed calculation method, the publication of which is expected in the next issue of the "Vestnik MGSU" the above mentioned shortcomings of the existing calculation methods, as well as the shortcomings listed in this article are eliminated, which results in the higher convergence of theoretical and experimental results of eccentrically compressed concrete elements strength and hence a high reliability of their operation.
Simple energy-calculation method for solar industrial-process-heat steam systems
Gee, R. C.
1983-01-01
Designing a solar industrial process heat (IPH) system, sizing its components and predicting its annual energy delivery requires a method for calculating solar system performance. A calculation method that is accurate, easy to use, accounts for the impact of all important system parameters, and does not require use of a computer is described. Only simple graphs and a hand calculator are required to predict annual collector field performance and annual system losses. The energy calculation method is applicable to a variety of solar system configurations. The calculation method applied only to parabolic trough steam generation systems that do not employ thermal storage is described. Both flash tank and unfired boiler steam systems are covered.
Maskew, B.
1976-01-01
A discrete singularity method has been developed for calculating the potential flow around two-dimensional airfoils. The objective was to calculate velocities at any arbitrary point in the flow field, including points that approach the airfoil surface. That objective was achieved and is demonstrated here on a Joukowski airfoil. The method used combined vortices and sources ''submerged'' a small distance below the airfoil surface and incorporated a near-field subvortex technique developed earlier. When a velocity calculation point approached the airfoil surface, the number of discrete singularities effectively increased (but only locally) to keep the point just outside the error region of the submerged singularity discretization. The method could be extended to three dimensions, and should improve nonlinear methods, which calculate interference effects between multiple wings, and which include the effects of force-free trailing vortex sheets. The capability demonstrated here would extend the scope of such calculations to allow the close approach of wings and vortex sheets (or vortices).
Combination of measurements and the BLUE method
Lista, Luca
2016-01-01
The most accurate method to combine measurement from different experiments is to build a combined likelihood function and use it to perform the desired inference. This is not always possible for various reasons, hence approximate methods are often convenient. Among those, the best linear unbiased estimator (BLUE) is the most popular, allowing to take into account individual uncertainties and their correlations. The method is unbiased by construction if the true uncertainties and their correlations are known, but it may exhibit a bias if uncertainty estimates are used in place of the true ones, in particular if those estimated uncertainties depend on measured values. In those cases, an iterative application of the BLUE method may reduce the bias of the combined measurement.
Hamming method for solving the delayed neutron precursor concentration for reactivity calculation
International Nuclear Information System (INIS)
Highlights: ► We present a new formulation to calculate the reactivity using the Hamming method. ► This method shows better accuracy than existing methods for reactivity calculation. ► The reactivity is calculated without limitation of the nuclear power form. ► The method can be implemented in reactivity meters with time step of up to 0.1 s. - Abstract: We propose a new method for numerically solving the inverse point kinetic equation for a nuclear reactor using the Hamming method, without requiring the nuclear power history and without using the Laplace transform. This new method converges with accuracy of order h5, where h is the step in the computation time. The procedure is validated for different forms of the nuclear power and with different time steps. The results indicate that this method has a better accuracy and lower computational effort compared with other conventional methods that use the nuclear power history.
COMET-PE: an incident fluence response expansion transport method for radiotherapy calculations
Hayward, Robert M.; Rahnema, Farzad
2013-05-01
Accurate dose calculation is a central component of radiotherapy treatment planning. A new method of dose calculation has been developed based on transport theory and validated by comparison to Monte Carlo methods. The coarse mesh transport method has been extended to allow coupled photon-electron transport in 3D. The method combines stochastic pre-computation with a deterministic solver to achieve high accuracy and precision. To enhance the method for radiotherapy calculations, a new angular basis was derived, and an analytical source treatment was developed. Validation was performed by comparison to DOSXYZnrc using a heterogeneous interface phantom composed of water, aluminum, and lung. Calculations of both kinetic energy released per unit mass and dose were compared. Good agreement was found with a maximum error and root mean square relative error of less than 1.5% for all cases. The results show that the new method achieves an accuracy comparable to Monte Carlo.
Lahti, G. P.; Mueller, R. A.
1973-01-01
Measurements of MeV neutron were made at the surface of a lithium hydride and depleted uranium shielded reactor. Four shield configurations were considered: these were assembled progressively with cylindrical shells of 5-centimeter-thick depleted uranium, 13-centimeter-thick lithium hydride, 5-centimeter-thick depleted uranium, 13-centimeter-thick lithium hydride, 5-centimeter-thick depleted uranium, and 3-centimeter-thick depleted uranium. Measurements were made with a NE-218 scintillation spectrometer; proton pulse height distributions were differentiated to obtain neutron spectra. Calculations were made using the two-dimensional discrete ordinates code DOT and ENDF/B (version 3) cross sections. Good agreement between measured and calculated spectral shape was observed. Absolute measured and calculated fluxes were within 50 percent of one another; observed discrepancies in absolute flux may be due to cross section errors.
Calculation of transmutation in copper and comparison with measured electrical properties
International Nuclear Information System (INIS)
Calculations of the transmutation of pure cooper have been performed for the Fast Flux Test Facility/Materials Open Test Assembly (FFTF/MOTA) and for the STARFIRE first-wall fusion reactor. The principal transmutation products in decreasing order of importance are nickel, zinc, and cobalt. Contrary to previously published calculations, nickel and zinc are produced at nearly equal rates in FFTF, but cobalt is insignificant. The fusion reactor case shows much higher transmutation rates and produces about twice as much nickel as zinc. Transmutation rates for FFTF were determined using adjusted neutron energy spectra based on dosimetry measurements at various positions in the MOTA. The predicted transmutation rates were compared directly with nickel concentrations measured by Energy Dispersive X-Ray Spectrometry (EDS) microchemistry and with measurements of the electrical conductivity of copper and two copper alloys irradiated in the MOTA. Measurements and calculations agree within ±15%
Integration of optical measurement methods with flight parameter measurement systems
Kopecki, Grzegorz; Rzucidlo, Pawel
2016-05-01
During the AIM (advanced in-flight measurement techniques) and AIM2 projects, innovative modern techniques were developed. The purpose of the AIM project was to develop optical measurement techniques dedicated for flight tests. Such methods give information about aircraft elements deformation, thermal loads or pressure distribution, etc. In AIM2 the development of optical methods for flight testing was continued. In particular, this project aimed at the development of methods that could be easily applied in flight tests in an industrial setting. Another equally important task was to guarantee the synchronization of the classical measuring system with cameras. The PW-6U glider used in flight tests was provided by the Rzeszów University of Technology. The glider had all the equipment necessary for testing the IPCT (image pattern correlation technique) and IRT (infrared thermometry) methods. Additionally, equipment adequate for the measurement of typical flight parameters, registration and analysis has been developed. This article describes the designed system, as well as presenting the system’s application during flight tests. Additionally, the results obtained in flight tests show certain limitations of the IRT method as applied.
Measurement error models, methods, and applications
Buonaccorsi, John P
2010-01-01
Over the last 20 years, comprehensive strategies for treating measurement error in complex models and accounting for the use of extra data to estimate measurement error parameters have emerged. Focusing on both established and novel approaches, ""Measurement Error: Models, Methods, and Applications"" provides an overview of the main techniques and illustrates their application in various models. It describes the impacts of measurement errors on naive analyses that ignore them and presents ways to correct for them across a variety of statistical models, from simple one-sample problems to regres
Track detection methods of radium measurements
International Nuclear Information System (INIS)
The principles of tack formation and processing including the description of etching and etch-track evaluation for the preferably used plastic track detectors are discussed. Measuring methods to determine 226Ra activity based either on the mapping of alpha-decaying elements in the complete U-Ra series by alpha-radiography, or on the measurement of uranium alone by neutron induced fissionography, or on the alpha-decay measurement of 222Rn, the first daughter element of radium, and finally on the measurement of alpha-tracks originating from radium itself, which is separated from its parent nuclides are described in detail. (V.N.)
A new method for calculating the average period of current assets turnover in the analyzed period
Kulakova Julija Nikolaevna; Kulakov Andrej Borisovich
2015-01-01
The aim of this study is to develop a new method for calculating the average period of current assets turnover during the analyzed period without using of financial results (revenue, cost, etc.). To prove the advantages of the proposed method in comparison with the traditional method of calculating turnover the example of estimating the mean residence time in the analyzed period of working capital in the form of receivables is developed.
A new method for calculating the average period of current assets turnover in the analyzed period
Directory of Open Access Journals (Sweden)
Kulakova Julija Nikolaevna
2015-05-01
Full Text Available The aim of this study is to develop a new method for calculating the average period of current assets turnover during the analyzed period without using of financial results (revenue, cost, etc.. To prove the advantages of the proposed method in comparison with the traditional method of calculating turnover the example of estimating the mean residence time in the analyzed period of working capital in the form of receivables is developed.
Methods of Cost Accounting and Production Costs Calculation: Merits and Demerits
Alla Pohosova; Olena Yarmolyuk
2012-01-01
The methods of cost accounting and calculation of production costs, including standard-cost, direct-costing, re-distribution and customized ones, their advantages and disadvantages have been analyzed. The proposals on the implementation of methods of cost accounting and production cost calculation in agricultural enterprises have been given. In addition, the application of the combined method of cost accounting of dairy cattle-breeding output has been accentuated
Sklerov, Jason H; Couper, Fiona J
2011-09-01
An estimate was made of the measurement uncertainty for blood ethanol testing by headspace gas chromatography. While uncertainty often focuses on compliance to a single threshold level (0.08 g/100 mL), the existence of multiple thresholds, related to enhanced sentencing, subject age, or commercial vehicle licensure, necessitate the use of an estimate with validity across multiple specification levels. The uncertainty sources, in order of decreasing magnitude, were method reproducibility, linear calibration, recovery, calibrator preparation, reference material, and sample preparation. A large set of reproducibility data was evaluated (n = 15,433) in order to encompass measurement variability across multiple conditions, operators, instruments, concentrations and timeframes. The relative, combined standard uncertainty was calculated as ±2.7%, with an expanded uncertainty of ±8.2% (99.7% level of confidence, k = 3). Bias was separately evaluated through a recovery study using standard reference material from a national metrology institute. The uncertainty estimate was verified through the use of proficiency test (PT) results. Assigned values for PT results and their associated uncertainties were calculated as robust means (x*) and standard deviations (s*) of participant values. Performance scores demonstrated that the uncertainty estimate was appropriate across the full range of PT concentrations (0.010-0.370 g/100 mL). The use of PT data as an empirical estimate of uncertainty was not examined. Until providers of blood ethanol PT samples include details on how an assigned value is obtained along with its uncertainty and traceability, the use of PT data should be restricted to the role of verification of uncertainty estimates.
A new finite cloud method for calculating external exposure dose in a nuclear emergency
International Nuclear Information System (INIS)
A new finite cloud method (5/μ method) for calculating external exposure dose in a nuclear emergency is presented in this paper. The method calculates external exposure dose over a specially constructed three-dimensional columned space, whose underside center is the location of the receptor and underside radius and height are both five times mean free path of a gamma-photon. Then, the space is divided into many grid cells for integral to calculate external exposure dose (or dose rate). The calculation values of air external exposure dose rate conversion factors and air-absorbed dose rate conversion factors by the 5/μ method are accordant with the values presented in related references. Comparing with the discrete point approximation method (DPA) [USNRC, The MESORAD Dose Assessment Model. NUREG/CR-4000 Vol. 1, 1986] and the Nomogram method [USNRC, Nomogram for Evaluation of Doses from Finite Noble Gas Clouds, NUREG-0851, 1983], which are two traditional finite cloud methods for calculating external exposure dose, the 5/μ method has a distinct advantage of more fast calculation speed, which is very important in a nuclear emergency. What is more, the 5/μ method can be applied together with three-dimensional atmospheric dispersion models
A new finite cloud method for calculating external exposure dose in a nuclear emergency
Energy Technology Data Exchange (ETDEWEB)
Wang, X.Y.; Ling, Y.S. E-mail: lingyongsheng00@mails.tsinghua.edu.cn; Shi, Z.Q
2004-06-01
A new finite cloud method (5/{mu} method) for calculating external exposure dose in a nuclear emergency is presented in this paper. The method calculates external exposure dose over a specially constructed three-dimensional columned space, whose underside center is the location of the receptor and underside radius and height are both five times mean free path of a gamma-photon. Then, the space is divided into many grid cells for integral to calculate external exposure dose (or dose rate). The calculation values of air external exposure dose rate conversion factors and air-absorbed dose rate conversion factors by the 5/{mu} method are accordant with the values presented in related references. Comparing with the discrete point approximation method (DPA) [USNRC, The MESORAD Dose Assessment Model. NUREG/CR-4000 Vol. 1, 1986] and the Nomogram method [USNRC, Nomogram for Evaluation of Doses from Finite Noble Gas Clouds, NUREG-0851, 1983], which are two traditional finite cloud methods for calculating external exposure dose, the 5/{mu} method has a distinct advantage of more fast calculation speed, which is very important in a nuclear emergency. What is more, the 5/{mu} method can be applied together with three-dimensional atmospheric dispersion models.
Transmutation of technetium in the Petten HFR. A comparison of measurements and calculations
Energy Technology Data Exchange (ETDEWEB)
Kloosterman, J.L.; Hendriks, J.A.; Konings, R.J.M.
1996-10-01
Within the framework of the EFTTRA cooperation between CEA, ECN, EDF, FZK, IAM and ITU, six metallic {sup 99}Tc rods have been irradiated in the Petten HFR for 193 effective full power days. During this irradiation, more than 6% of the {sup 99}Tc has been transmuted to the stable {sup 100}Ru. At ECN, one of the six rods has been examined in the hot cell laboratory. The ruthenium concentration in the rod measured by Isotope Dilution Mass Spectrometry reaches 6.4% at 5 mm from the bottom of the rod and 6.0% at 5 mm from the top. Also the axial and radial distributions of the ruthenium have been measured by Electron Probe Micro Analysis. The ruthenium concentrations calculated by the three-dimensional Monte Carlo code KENO reach 6.1% at 5 mm from the bottom of the rod and 5.7% at 5 mm from the top. These values are in reasonable agreement with the measured ones. However, the calculated radial distribution of the ruthenium concentration is not in agreement with the measurements. The radial profile calculated by the Monte Carlo code MCNP, which uses a point-wise cross-section library, agrees much better with the measurements. To solve the remaining small differences between the measured and calculated ruthenium concentrations in the rod, the thermal absorption cross section of {sup 99}Tc will be measured in the Petten HFR in the course of this year. (orig.).
International Nuclear Information System (INIS)
The programme CARE (calculation of the annual radiation exposure) calculates the annual environmental exposure of complex nuclear installations. In the diffusion calculation of pollutants, the real weather conditions of the year concerned are taken into account on an hourly basis together with the associated release rates measured for the various nuclides of individual emitters. According to their location in the plant, the contributions of the time-integrated pollutant concentrations of the individual emitters are superimposed at predefinable receiving points in the vicinity or on the boundary of an installation (plant fencing). In the conception of models for calculating the resultant 50-year dose commitments care was taken to ensure that the programme CARE is capable of treating both individual emissions limited in time and quasi-continuous emissions. The programme CARE can therefore be used also for a subsequent calculation of radiation exposure in the event of accidents. (orig.)
Directory of Open Access Journals (Sweden)
M. Malík
2014-01-01
Full Text Available This paper deals with the effects surrounding phenomenon of a mechanical force generated on a high voltage asymmetrical capacitor (the so called Biefeld-Brown effect. A method to measure this force is described and a formula to calculate its value is also given. Based on this the authors derive a formula characterising the neutral air flow velocity impacting an asymmetrical capacitor connected to high voltage. This air flow under normal circumstances lessens the generated force. In the following part this velocity is measured using Particle Image Velocimetry measuring technique and the results of the theoretically calculated velocity and the experimentally measured value are compared. The authors found a good agreement between the results of both approaches.
Entanglement as Measure of Electron-Electron Correlation in Quantum Chemistry Calculations
Huang, Zhen; Kais, Sabre
2005-01-01
In quantum chemistry calculations, the correlation energy is defined as the difference between the Hartree-Fock limit energy and the exact solution of the nonrelativistic Schrodinger equation. With this definition, the electron correlation effects are not directly observable. In this report, we show that the entanglement can be used as an alternative measure of the electron correlation in quantum chemistry calculations. Entanglement is directly observable and it is one of the most striking pr...
Simple and fast cosine approximation method for computer-generated hologram calculation.
Nishitsuji, Takashi; Shimobaba, Tomoyoshi; Kakue, Takashi; Arai, Daisuke; Ito, Tomoyoshi
2015-12-14
The cosine function is a heavy computational operation in computer-generated hologram (CGH) calculation; therefore, it is implemented by substitution methods such as a look-up table. However, the computational load and required memory space of such methods are still large. In this study, we propose a simple and fast cosine function approximation method for CGH calculation. As a result, we succeeded in creating CGH with sufficient quality and made the calculation time 1.6 times as fast at maximum compared to using the look-up table of the cosine function on CPU implementation.
A New Power Calculation Method for Single-Phase Grid-Connected Systems
DEFF Research Database (Denmark)
Yang, Yongheng; Blaabjerg, Frede
2013-01-01
A new method to calculate average active power and reactive power for single-phase systems is proposed in this paper. It can be used in different applications where the output active power and reactive power need to be calculated accurately and fast. For example, a grid-connected photovoltaic...... system in low voltage ride through operation mode requires a power feedback for the power control loop. Commonly, a Discrete Fourier Transform (DFT) based power calculation method can be adopted in such systems. However, the DFT method introduces at least a one-cycle time delay. The new power calculation...... method, which is based on the adaptive filtering technique, can achieve a faster response. The performance of the proposed method is verified by experiments and demonstrated in a 1 kW single-phase grid-connected system operating under different conditions.Experimental results show the effectiveness of...
Thermal conductivity of anisotropic snow measured by three independent methods
Directory of Open Access Journals (Sweden)
F. Riche
2012-05-01
Full Text Available The thermal conductivity of snow determines the temperature gradient, and by this the rate of snow metamorphism. It is therefore a key property of snow. However, parameterizations of thermal conductivity measured with the transient needle probe and the steady-state heat-flux plate show a bias. In addition, it is not clear to which degree thermal anisotropy is relevant. Until now, no physically convincing argument for the existence of this bias could be found. In this study, we investigated three independent methods to measure snow thermal conductivity and its anisotropy: a needle probe with a long heating time, a guarded heat flux plate, and direct numerical simulation at the level of the pore and ice structure. The three methods were applied to identical snow samples, apart from the different measurement volumes of each methods. We analyzed the consistency and the difference between these methods. We found a distinct change from horizontal thermal anisotropy in small rounded grains and vertical anisotropy in depth hoar. The anisotropy between vertical and horizontal conductivity ranges between 0.5–2. This anisotropy can cause a difference of up to −25 % to + 25 % if the thermal conductivity is calculated only from a horizontally inserted needle probe. Based on these measurements, the direct numerical simulation is the most reliable method as the tensorial components of the thermal conductivity can be calculated, the corresponding microstructure is precisely known and the homogeneity of the sample can be determined.
A method for numerical calculation of propeller hydrodynamics in unsteady inflow
Institute of Scientific and Technical Information of China (English)
HUANG Sheng; WANG Pei-sheng; HU Jian
2007-01-01
The hydrodynamic performance of a propeller in unsteady inflow was calculated using the surface panel method. The surfaces of blades and hub were discreted by a number of hyperboloidal quadrilateral panels with constant source and doublet distribution. Each panel's comer coordinates were calculated by spline interpolation between the main parameter and the blade geometry of the propeller.The integral equation was derived using the Green Formula.The influence coefficient of the matrix was calculated by the Morino analytic formula. The tangential velocity distribution was calculated with the Yanagizawa method, and the pressure coefficient was calculated using the Bonuli equation. The pressure Kutta condition was satisfied at the trailing edge of the propeller blade using the Newton-Raphson iterative procedure, so as to make the pressure coefficients of the suction and pressure faces of the blade equal at the trailing edge. Calculated results for the propeller in steady inflow were taken as initialization values for the unsteady inflow calculation process. Calculations were carried out from the moment the propeller achieved steady rotation. At each time interval, a linear algebraic equation combined with Kutta condition was established on a key blade and solved numerically. Comparison between calculated results and experimental results indicates that this method is correct and effective.
Directory of Open Access Journals (Sweden)
Shan Yang
2016-01-01
Full Text Available Power flow calculation and short circuit calculation are the basis of theoretical research for distribution network with inverter based distributed generation. The similarity of equivalent model for inverter based distributed generation during normal and fault conditions of distribution network and the differences between power flow and short circuit calculation are analyzed in this paper. Then an integrated power flow and short circuit calculation method for distribution network with inverter based distributed generation is proposed. The proposed method let the inverter based distributed generation be equivalent to Iθ bus, which makes it suitable to calculate the power flow of distribution network with a current limited inverter based distributed generation. And the low voltage ride through capability of inverter based distributed generation can be considered as well in this paper. Finally, some tests of power flow and short circuit current calculation are performed on a 33-bus distribution network. The calculated results from the proposed method in this paper are contrasted with those by the traditional method and the simulation method, whose results have verified the effectiveness of the integrated method suggested in this paper.
Human performance assessment: methods and measures
International Nuclear Information System (INIS)
The Human Error Analysis Project (HEAP) was initiated in 1994. The aim of the project was to acquire insights on how and why cognitive errors occur when operators are engaged in problem solving in advanced integrated control rooms. Since human error had not been studied in the HAlden Man-Machine LABoratory (HAMMLAB) before, it was also necessary to carry out research in methodology. In retrospect, it is clear that much of the methodological work is relevant to human-machine research in general, and not only to research on human error. The purpose of this report is, therefore, to give practitioners and researchers an overview of the methodological parts of HEAP. The scope of the report is limited to methods used throughout the data acquisition process, i.e., data-collection methods, data-refinement methods, and measurement methods. The data-collection methods include various types of verbal protocols, simulator logs, questionnaires, and interviews. Data-refinement methods involve different applications of the Eyecon system, a flexible data-refinement tool, and small computer programs used for rearranging, reformatting, and aggregating raw-data. Measurement methods involve assessment of diagnostic behaviour, erroneous actions, complexity, task/system performance, situation awareness, and workload. The report concludes that the data-collection methods are generally both reliable and efficient. The data-refinement methods, however, should be easier to use in order to facilitate explorative analyses. Although the series of experiments provided an opportunity for measurement validation, there are still uncertainties connected to several measures, due to their reliability still being unknown. (Author). 58 refs.,7 tabs
Methods of viscosity measurements in sealed ampoules
Mazuruk, Konstantin
1999-07-01
Viscosity of semiconductors and metallic melts is usually measured by oscillating cup method. This method utilizes the melts contained in vacuum sealed silica ampoules, thus the problems related to volatility, contamination, and high temperature and pressure can be alleviate. In a typical design, the time required for a single measurement is of the order of one hour. In order to reduce this time to a minute range, a high resolution angular detection system is implemented in our design of the viscometer. Furthermore, an electromagnet generating a rotational magnetic field (RMF) is incorporated into the apparatus. This magnetic field can be used to remotely and nonintrusively measure the electrical conductivity of the melt. It can also be used to induce a well controlled rotational flow in the system. The transient behavior of this flow can potentially yield of the fluid. Based on RMF implementation, two novel viscometry methods are proposed in this work: a) the transient torque method, b) the resonance method. A unified theoretical approach to the three methods is presented along with the initial test result of the constructed apparatus. Advantages of each of the method are discussed.
Calculation of electrostatic fields in ionic crystals by a Bertaut method
Weenk, J.W.; Harwig, H.A.
1975-01-01
A method to calculate the electrostatic field strength in ionic crystals is evaluated according to a model by Bertaut. Formulae for the self potential and the field strength at an ion site are derived. The practical use is demonstrated by calculations of field vectors in TiO2 (rutile, anatase, brook
The ion exchange and its connection the industry II.- Calculation methods for installations
International Nuclear Information System (INIS)
An exposure is made of calculation methods for ion exchange installations based on kinetic considerations and similarity with other unitary operations. Factors to be experimentally obtained as well as difficulties which may occur in its determination are also given. Calculation procedures most commonly used in industry are enclosed and explained with numerical resolution of a problem of water demineralization. (Author) 22 refs
Measurement and calculations of laminar flow in a ninety degree bifurcation.
Liepsch, D; Moravec, S; Rastogi, A K; Vlachos, N S
1982-01-01
Measurements and numericaL calculations of laminar flow in a plane 90 degrees bifurcation are presented. The corresponding two-dimensional steady flow Navier-Stokes equations solved by a finite-difference procedure employing pressure and velocity as dependent variables. The influence of Reynolds number and mass flow ratio on the velocity field, streamlines, local shear stress and pressure drop are quantified and shown to be substantial. The circulation patterns and shear stresses are examined in view of available data regarding the formation of atherotic plaques in the human circulatory system. The calculated velocity profiles are compared with measurements obtained with laser Doppler anemometry and the agreement is shown to be satisfactory. Calculations outside the range of measurements which are of value to biomechanics are also presented.
Two-temperature method for measuring emissivity
Watson, K.
1992-01-01
Spectral emissivity can be uniquely determined from radiance measurements if the object can be observed at two different temperatures. The advantage of this approach is that the spectral emissivity is determined without a priori assumptions about spectral shape. Because the different temperatures are obtained by observing the scene at two times in the diurnal cycle (optimally after midday and midnight), the method assumes that emissivity is temporally invariant. This is valid for rocks and dry soils, not well established for vegetation, and not true when changes in soil moisture occur between the measurements. Accurate image registration and satisfactory signal:noise are critical factors that limit extensive use of this method. ?? 1992.
Penetration depth time history measurement method
Liu, C; Ahrens, T. J.
2000-01-01
A new method for measuring the depth time history of rigid body penetration into brittle materials under a deceleration of ~10^5 g. The method includes: sabot-projectile, sabot-projectile separation and penetration depth detection systems. Relatively small intrinsic time error (3%) and depth error (0.3–0.7 mm) results. Penetration depth time history in a series of 4140 steel projectile penetrations into a mortar are measured at velocities of 100 to 500 m/sec with sufficient accuracy such that...
THE USE OF REPEAD MEASUREMENTS METHOD FOR
Directory of Open Access Journals (Sweden)
Gürol ZIRHLIOĞLU
2009-08-01
Full Text Available The repeated measurements method is used to get information about one or more than one effects of factors by means of repeated experiments in different place, time and materials. In this study, mixed model method related tok repeated measurement is used for the analysis of the Turkish Women’s National Volleyball Team players who participated World Championship which organizated in Japan in 2006 and investigated players perfomance whether changed according to mathces and won points scored. According to the results, it is concluded that significant differences between players’ match performance might be obtained.
Applying Activity Based Costing (ABC Method to Calculate Cost Price in Hospital and Remedy Services
Directory of Open Access Journals (Sweden)
A Dabiri
2012-04-01
Full Text Available Background: Activity Based Costing (ABC is one of the new methods began appearing as a costing methodology in the 1990. It calculates cost price by determining the usage of resources. In this study, ABC method was used for calculating cost price of remedial services in hospitals.Methods: To apply ABC method, Shahid Faghihi Hospital was selected. First, hospital units were divided into three main departments: administrative, diagnostic, and hospitalized. Second, activity centers were defined by the activity analysis method. Third, costs of administrative activity centers were allocated into diagnostic and operational departments based on the cost driver. Finally, with regard to the usage of cost objectives from services of activity centers, the cost price of medical services was calculated.Results: The cost price from ABC method significantly differs from tariff method. In addition, high amount of indirect costs in the hospital indicates that capacities of resources are not used properly.Conclusion: Cost price of remedial services with tariff method is not properly calculated when compared with ABC method. ABC calculates cost price by applying suitable mechanisms but tariff method is based on the fixed price. In addition, ABC represents useful information about the amount and combination of cost price services.
Four Methods for Calculating Blood-loss after Total Knee Arthroplasty
Institute of Scientific and Technical Information of China (English)
Fu-Qiang Gao; Zi-Jian Li; Ke Zhang; Wei Sun; Hong Zhang
2015-01-01
Background:Currently,various calculation methods for evaluating blood-loss in patients with total knee arthroplasty (TKA) are applied in clinical practice.However,different methods may yield different results.The purpose of this study was to determine the most reliable method for calculating blood-loss after primary TKA.Methods:We compared blood-loss in 245 patients who underwent primary unilateral TKA from February 2010 to August 2011.We calculated blood-loss using four methods:Gross equation,hemoglobin (Hb) balance,the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula,and Hb-dilution.We determined Pearson's correlation coefficients for the four methods.Results:There were large differences in the calculated blood-loss obtained by the four methods.In descending order of combined correlation coefficient based on calculated blood-loss,the methods were Hb-balance,OSTHEO formula,Hb-dilution,and Gross equation.Conclusions:The Hb-balance method may be the most reliable method of estimating blood-loss after TKA.
Efficiency measurement of hydro machine by thermodynamic method
Energy Technology Data Exchange (ETDEWEB)
Patil, Shantaram S.; Kumar, Arun [Indian Institute of Technology Roorkee, Uttarakhand (India). Alternate Hydro Energy Centre], E-mails: patiliitr@gmail.com, aheciitr@gmail.com; Verma, H.K. [Indian Institute of Technology Roorkee, Uttarakhand (India). Dept. of Electrical Engineering], E-mail: hkvfee@gmail.com
2011-10-15
The thermodynamic method is an absolute method of measuring hydraulic efficiency of hydraulic machines based on the principle of conservation of energy, i.e. first law of thermodynamics. The efficiency is calculated directly from the specific hydraulic energy and specific mechanical energy equations. The temperature difference between the inlet and outlet of the machine is very small, typically of the order of a few milli-Kelvins. Hence it is a very difficult and critical task to measure the temperature rise accurately. High-resolution high-accuracy data acquisition system along with precision type temperature sensors are essential for temperature measurements. Efficiency measurement using thermodynamic method has been carried out by the authors in laboratory, both on a turbine and a pump, using stable temperature sensors, electronic pressure transmitters and high-precision high-resolution data acquisition system. Thermo-wells are formed at inlet and outlet of the machine under test for simultaneous temperature measurement at both the points. High-precision RTDs of Pt-100 type (class 1/10 DIN, 0.03 deg C accuracy) are used for the measurement of temperatures. The results of efficiency measurement of turbine and pump in laboratory using thermodynamic method have been found to be very satisfactory. The same instrumentation with suitable adaptation can be used for the efficiency measurement on site. (author)
Energy Technology Data Exchange (ETDEWEB)
Perfetti, C.; Martin, W. [Univ. of Michigan, Dept. of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104 (United States); Rearden, B.; Williams, M. [Oak Ridge National Laboratory, Reactor and Nuclear Systems Div., Bldg. 5700, P.O. Box 2008, Oak Ridge, TN 37831-6170 (United States)
2012-07-01
Three methods for calculating continuous-energy eigenvalue sensitivity coefficients were developed and implemented into the Shift Monte Carlo code within the SCALE code package. The methods were used for two small-scale test problems and were evaluated in terms of speed, accuracy, efficiency, and memory requirements. A promising new method for calculating eigenvalue sensitivity coefficients, known as the CLUTCH method, was developed and produced accurate sensitivity coefficients with figures of merit that were several orders of magnitude larger than those from existing methods. (authors)
Fast calculation of spherical computer generated hologram using spherical wave spectrum method.
Jackin, Boaz Jessie; Yatagai, Toyohiko
2013-01-14
A fast calculation method for computer generation of spherical holograms in proposed. This method is based on wave propagation defined in spectral domain and in spherical coordinates. The spherical wave spectrum and transfer function were derived from boundary value solutions to the scalar wave equation. It is a spectral propagation formula analogous to angular spectrum formula in cartesian coordinates. A numerical method to evaluate the derived formula is suggested, which uses only N(logN)2 operations for calculations on N sampling points. Simulation results are presented to verify the correctness of the proposed method. A spherical hologram for a spherical object was generated and reconstructed successfully using the proposed method.
Integral method for the calculation of three-dimensional, laminar and turbulent boundary layers
Stock, H. W.
1978-01-01
The method for turbulent flows is a further development of an existing method; profile families with two parameters and a lag entrainment method replace the simple entrainment method and power profiles with one parameter. The method for laminar flows is a new development. Moment of momentum equations were used for the solution of the problem, the profile families were derived from similar solutions of boundary layer equations. Laminar and turbulent flows at the wings were calculated. The influence of wing tapering on the boundary layer development was shown. The turbulent boundary layer for a revolution ellipsoid is calculated for 0 deg and 10 deg incidence angles.
Methods of equipment depreciation calculating%设备折旧计算方法
Institute of Scientific and Technical Information of China (English)
杨晓雁
2011-01-01
For equipment management system equipment depreciation of computational problems, this paper puts forward several calculation method of equipment depreciation, and expounded the workload method, average life method and sum-of-years method, declining - balance, calculation methods.%针对仪器设备管理系统中设备折旧的计算问题,提出了设备折旧的几种计算方法,详细阐述了工作量法、平均年限法、年数总和法、双倍余额递减法的计算方法.
Calculating Methods of Inertia Moment of Turbo-Generator Rotor Using Load Rejection Test
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Calculated results of inertia moment of turbo-generator rotor can be quite different by methods used in load rejection tests. In view of fluctuation features of rotor speed rise curve during load rejection tests, the measurement principle of rotor inertia moment was expounded. Based on the measured data in load rejection tests for an imported type of domestic 300-MW generating unit, the rotor speed rise curve was fitted with three kinds of functions to get initial runup rate, but the obtained results differed a lot from each other. According to analysis on the mechanism of rotor speed rise, m=2 consecutive points averaging or FFT (Fast Fourier Transform) smoothing technology was introduced to process test data, and then the initial runup rate was determined by the method of linear fitting of rotor speed in the range of governing valve closing time. Although the obtained curves had a fluctuating shape, the results of rotor inertia moment for 50% and 100% load rejection tests were of good consistency.
Sediment load calculations from point measurements in sand-bed rivers
Institute of Scientific and Technical Information of China (English)
Seema C SHAH-FAIRBANK; Pierre Y JULIEN
2015-01-01
Point velocity and suspended sediment concentration measurements are used to calculate the total sediment discharge in sand-bed rivers. Calculations with the Series Expansion of the Modified Einstein Point Procedure (SEMEPP) depend on grain diameterds and settling velocityω, flow depthh, shear velocityu*, and sampling depthhp. This procedure extends the applicability of the Modified Einstein Procedure (MEP) by using point sediment concentration and velocity measurements. This procedure is tested using the laboratory data from Coleman, and field measurements from the Enoree, Middle Rio Grande and Mississippi Rivers. Based on 801 point measurements over 124 verticals at flow depths ranging from 0.17 m to 33.5 m and sediment concentrations less than 0.1 kg L-1, the accuracy of the calculations depends onu*/ω andhp/ds. Point measurement techniques like SEMEPP are well-suited whenu*/ω > 5 where at least 60% of the total sediment load is measured when 90% of the flow depth is sampled. The determination of sediment discharge from point measurements is most accurate in deep rivers whenhp/ds > 10,000, andu*/ω > 10. Point measurements are not well-suited for shallow rivers and laboratory flumes whereh< 0.5 m and whenu*/ω < 2.
Energy Technology Data Exchange (ETDEWEB)
Lee, C.E.
1976-08-01
The Volterra method of the multiplicative integral is used to determine the isotopic density, mass, and energy production in linear systems. The solution method, assumptions, and limitations are discussed. The method allows a rapid accurate calculation of the change in isotopic density, mass, and energy production independent of the magnitude of the time steps, production or decay rates, or flux levels.
Monte-Carlo Method Python Library for dose distribution Calculation in Brachytherapy
International Nuclear Information System (INIS)
The Cs-137 Brachytherapy treatment is performed in Madagascar since 2005. Time treatment calculation for prescribed dose is made manually. Monte-Carlo Method Python library written at Madagascar INSTN is experimentally used to calculate the dose distribution on the tumour and around it. The first validation of the code was done by comparing the library curves with the Nucletron company curves. To reduce the duration of the calculation, a Grid of PC's is set up with listner patch run on each PC. The library will be used to modelize the dose distribution in the CT scan patient picture for individual and better accuracy time calculation for a prescribed dose.
Energy Technology Data Exchange (ETDEWEB)
Dickerson, M.H.
1980-08-01
ARAC was on-line calculating hourly concentration values during the TMI-2 venting of /sup 85/Kr gas from June 28 to July 11, 1980. During this time hourly isopleths of normalized instantaneous concentration were calculated and transmitted to EPA in Middletown, PA. These isopleths were used to help locate the EPA and Penn State mobile air samplers and they were used for comparison to the EPA fixed 24 hr sampler measurements and the DOE helicopter measurements. This report summarizes preliminary comparisons for the EPA fixed samplers and the DOE helicopters.
The adaptation of methods in multilayer optics for the calculation of specular neutron reflection
International Nuclear Information System (INIS)
The adaptation of standard methods in multilayer optics to the calculation of specular neutron reflection is described. Their application is illustrated with examples which include a glass optical flat and a deuterated Langmuir-Blodgett film. (author)
Universal method of strictly calculating self-consistent fields of realistic plasma particles
H. Lin
2010-01-01
A universal method of strictly calculating self-consistent fields of realistic plasma particles could be strictly derived from three basic tools in theoretical plasma physics: particle simulation, Vlasov-Maxwell theory and fluid theory.
Improved method of generating bit reversed numbers for calculating fast fourier transform
Digital Repository Service at National Institute of Oceanography (India)
Suresh, T.
Fast Fourier Transform (FFT) is an important tool required for signal processing in defence applications. This paper reports an improved method for generating bit reversed numbers needed in calculating FFT using radix-2. The refined algorithm takes...
Energy Technology Data Exchange (ETDEWEB)
Sigg, K. C.; Coffield, R. D.
2002-09-01
High Reynolds number test data has recently been reported for both single and multiple piping elbow design configurations at earlier ASME Fluid Engineering Division conferences. The data of these studies ranged up to a Reynolds number of 42 x 10[sup]6 which is significantly greater than that used to establish design correlations before the data was available. Many of the accepted design correlations, based on the lower Reynolds number data, date back as much as fifty years. The new data shows that these earlier correlations are extremely conservative for high Reynolds number applications. Based on the recent high Reynolds number information a new recommended method has been developed for calculating irrecoverable pressure loses in piping systems for design considerations such as establishing pump sizing requirements. This paper describes the recommended design approach and additional testing that has been performed as part of the qualification of the method. This qualification testing determined the irrecoverable pressure loss of a piping configuration that would typify a limiting piping section in a complicated piping network, i.e., multiple, tightly coupled, out-of-plane elbows in series under high Reynolds number flow conditions. The overall pressure loss measurements were then compared to predictions, which used the new methodology to assure that conservative estimates for the pressure loss (of the type used for pump sizing) were obtained. The recommended design methodology, the qualification testing and the comparison between the predictions and the test data are presented. A major conclusion of this study is that the recommended method for calculating irrecoverable pressure loss in piping systems is conservative yet significantly lower than predicted by early design correlations that were based on the extrapolation of low Reynolds number test data.
Skrzyński, Witold
2014-11-01
The aim of this work was to create a model of a wide-bore Siemens Somatom Sensation Open CT scanner for use with GMCTdospp, which is an EGSnrc-based software tool dedicated for Monte Carlo calculations of dose in CT examinations. The method was based on matching spectrum and filtration to half value layer and dose profile, and thus was similar to the method of Turner et al. (Med. Phys. 36, pp. 2154-2164). Input data on unfiltered beam spectra were taken from two sources: the TASMIP model and IPEM Report 78. Two sources of HVL data were also used, namely measurements and documentation. Dose profile along the fan-beam was measured with Gafchromic RTQA-1010 (QA+) film. Two-component model of filtration was assumed: bow-tie filter made of aluminum with 0.5 mm thickness on central axis, and flat filter made of one of four materials: aluminum, graphite, lead, or titanium. Good agreement between calculations and measurements was obtained for models based on the measured values of HVL. Doses calculated with GMCTdospp differed from the doses measured with pencil ion chamber placed in PMMA phantom by less than 5%, and root mean square difference for four tube potentials and three positions in the phantom did not exceed 2.5%. The differences for models based on HVL values from documentation exceeded 10%. Models based on TASMIP spectra and IPEM78 spectra performed equally well. PMID:25028213
Calculation of Liquidus Temperature for Aluminum and Magnesium Alloys Applying Method of Equivalency
Directory of Open Access Journals (Sweden)
Mile B. Djurdjević
2013-01-01
Full Text Available The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influence of any alloying element on the liquidus temperature of an aluminum and/or magnesium alloy can be translated into the equivalent influence of a reference element. Silicon as a reference element has been chosen for aluminum alloys and aluminum for magnesium alloys. The sum of the equivalent concentrations for other elements, when added to the influence of the actual reference element is used to calculate the liquidus temperature of the alloy. The calculated liquidus temperatures for wide ranges of alloy chemical compositions show a good correlation with corresponding measured liquidus temperatures.
Numerical Methods for the Stray-Field Calculation: A Comparison of recently developed Algorithms
Abert, Claas; Selke, Gunnar; Drews, André; Schrefl, Thomas
2012-01-01
Different numerical approaches for the stray-field calculation in the context of micromagnetic simulations are investigated. We compare finite difference based fast Fourier transform methods, tensor grid methods and the finite-element method with shell transformation in terms of computational complexity, storage requirements and accuracy tested on several benchmark problems. These methods can be subdivided into integral methods (fast Fourier transform methods, tensor-grid method) which solve the stray field directly and in differential equation methods (finite-element method), which compute the stray field as the solution of a partial differential equation. It turns out that for cuboid structures the integral methods, which work on cuboid grids (fast Fourier transform methods and tensor grid methods) outperform the finite-element method in terms of the ratio of computational effort to accuracy. Among these three methods the tensor grid method is the fastest. However, the use of the tensor grid method in the c...
The effective atomic numbers of some biomolecules calculated by two methods: A comparative study
DEFF Research Database (Denmark)
Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif
2009-01-01
The effective atomic numbers Z(eff) of some fatty acids and amino acids have been calculated by two numerical methods, a direct method and an interpolation method, in the energy range of 1 keV-20 MeV. The notion of Z(eff) is given a new meaning by using a modern database of photon interaction cross...
A FINITE-DIFFERENCE, DISCRETE-WAVENUMBER METHOD FOR CALCULATING RADAR TRACES
A hybrid of the finite-difference method and the discrete-wavenumber method is developed to calculate radar traces. The method is based on a three-dimensional model defined in the Cartesian coordinate system; the electromagnetic properties of the model are symmetric with respect ...
Calculation of isotopic mass and energy production by a matrix operator method
International Nuclear Information System (INIS)
The Volterra method of the multiplicative integral is used to determine the isotopic density, mass, and energy production in linear systems. The solution method, assumptions, and limitations are discussed. The method allows a rapid accurate calculation of the change in isotopic density, mass, and energy production independent of the magnitude of the time steps, production or decay rates, or flux levels
COMPLEX INNER PRODUCT AVERAGING METHOD FOR CALCULATING NORMAL FORM OF ODE
Institute of Scientific and Technical Information of China (English)
陈予恕; 孙洪军
2001-01-01
This paper puts forward a complex inner product averaging method for calculating normal form of ODE. Compared with conventional averaging method, the theoretic analytical process has such simple forms as to realize computer program easily.Results can be applied in both autonomous and non-autonomous systems. At last, an example is resolved to verify the method.
Large uncertainty in soil carbon modelling related to carbon input calculation method
Keel, Sonja G.; Leifeld, Jens; Taghizadeh-Toosi, Arezoo; Oleson, Jørgen E.
2016-04-01
A model-based inventory for carbon (C) sinks and sources in agricultural soils is being established for Switzerland. As part of this project, five frequently used allometric equations that estimate soil C inputs based on measured yields are compared. To evaluate the different methods, we calculate soil C inputs for a long-term field trial in Switzerland. This DOK experiment (bio-Dynamic, bio-Organic, and conventional (German: Konventionell)) compares five different management systems, that are applied to identical crop rotations. Average calculated soil C inputs vary largely between allometric equations and range from 1.6 t C ha-1 yr-1 to 2.6 t C ha-1 yr-1. Among the most important crops in Switzerland, the uncertainty is largest for barley (difference between highest and lowest estimate: 3.0 t C ha-1 yr-1). For the unfertilized control treatment, the estimated soil C inputs vary less between allometric equations than for the treatment that received mineral fertilizer and farmyard manure. Most likely, this is due to the higher yields in the latter treatment, i.e. the difference between methods might be amplified because yields differ more. To evaluate the influence of these allometric equations on soil C dynamics we simulate the DOK trial for the years 1977-2004 using the model C-TOOL (Taghizadeh-Toosi et al. 2014) and the five different soil C input calculation methods. Across all treatments, C-TOOL simulates a decrease in soil C in line with the experimental data. This decline, however, varies between allometric equations (-2.4 t C ha-1 to -6.3 t C ha-1 for the years 1977-2004) and has the same order of magnitude as the difference between treatments. In summary, the method to estimate soil C inputs is identified as a significant source of uncertainty in soil C modelling. Choosing an appropriate allometric equation to derive the input data is thus a critical step when setting up a model-based national soil C inventory. References Taghizadeh-Toosi A et al. (2014) C
Assessment of formulas for calculating critical concentration by the agar diffusion method.
Drugeon, H.B.; Juvin, M E; Caillon, J.; Courtieu, A L
1987-01-01
The critical concentration of antibiotic was calculated by using the agar diffusion method with disks containing different charges of antibiotic. It is currently possible to use different calculation formulas (based on Fick's law) devised by Cooper and Woodman (the best known) and by Vesterdal. The results obtained with the formulas were compared with the MIC results (obtained by the agar dilution method). A total of 91 strains and two cephalosporins (cefotaxime and ceftriaxone) were studied....
New method for calculation of the Vander-Walls interaction constants
International Nuclear Information System (INIS)
A new method is proposed for calculating dispersion coefficients. The method is based on a qualitative idea of quasiclassic system of N particles within the limit of large d-dimensions of space. Pade-approximation enables to sum up efficiently the series of 1/d-decomposition and derive expressions for Van-der-Walls coefficients. Corrections related to nuclear mass finiteness are also calculated
Excited States Calculated by Means of the Linear Muffin-Tin Orbital Method
Alouani, M.; Wills, J M
1999-01-01
The most popular electronic structure method, the linear muffin-tin orbital method (LMTO), in its full-potential (FP) and relativistic forms has been extended to calculate the spectroscopic properties of materials form first principles, i.e, optical spectra, x-ray magnetic circular dichroism (XMCD) and magneto-optical kerr effect (MOKE). The paper describes an overview of the FP-LMTO basis set and the calculation of the momentum matrix elements. Some applications concerning the computation of...
Different methods of measuring ADC values in normal human brain
International Nuclear Information System (INIS)
Objective: To investigate better method of measuring ADC values of normal brain, and provide reference for further research. Methods: Twenty healthy people's MR imaging were reviewed. All of them underwent routine MRI scans and echo-planar diffusion-weighted imaging (DWI), and ADC maps were reconstructed on work station. Six regions of interest (ROI) were selected for each object, the mean ADC values were obtained for each position on DWI and ADC maps respectively. Results: On the anisotropic DWI map calculated in the hypothalamus, ADCM, ADCP, ADCS values were no significant difference (P>0.05), in the frontal white matter and internal capsule hindlimb, there was a significant difference (Pave value exist significant difference to direct measurement on the anisotropic (isotropic) ADC map (P<0.001). Conclusion: Diffusion of water in the frontal white matter and internal capsule are anisotropic, but it is isotropic in the hypothalamus; different quantitative methods of diffusion measurement of 4ADC values have significant difference, but ADC values calculated through the DWI map is more accurate, quantitative diffusion study of brain tissue should also consider the diffusion measurement method. (authors)
A new method for modeling rough membrane surface and calculation of interfacial interactions.
Zhao, Leihong; Zhang, Meijia; He, Yiming; Chen, Jianrong; Hong, Huachang; Liao, Bao-Qiang; Lin, Hongjun
2016-01-01
Membrane fouling control necessitates the establishment of an effective method to assess interfacial interactions between foulants and rough surface membrane. This study proposed a new method which includes a rigorous mathematical equation for modeling membrane surface morphology, and combination of surface element integration (SEI) method and the composite Simpson's approach for assessment of interfacial interactions. The new method provides a complete solution to quantitatively calculate interfacial interactions between foulants and rough surface membrane. Application of this method in a membrane bioreactor (MBR) showed that, high calculation accuracy could be achieved by setting high segment number, and moreover, the strength of three energy components and energy barrier was remarkably impaired by the existence of roughness on the membrane surface, indicating that membrane surface morphology exerted profound effects on membrane fouling in the MBR. Good agreement between calculation prediction and fouling phenomena was found, suggesting the feasibility of this method.
Calculation reduction method for color computer-generated hologram using color space conversion
Shimobaba, Tomoyoshi; Oikawa, Minoru; Takada, Naoki; Okada, Naohisa; Endo, Yutaka; Hirayama, Ryuji; Ito, Tomoyoshi
2013-01-01
We report a calculation reduction method for color computer-generated holograms (CGHs) using color space conversion. Color CGHs are generally calculated on RGB space. In this paper, we calculate color CGHs in other color spaces: for example, YCbCr color space. In YCbCr color space, a RGB image is converted to the luminance component (Y), blue-difference chroma (Cb) and red-difference chroma (Cr) components. In terms of the human eye, although the negligible difference of the luminance component is well-recognized, the difference of the other components is not. In this method, the luminance component is normal sampled and the chroma components are down-sampled. The down-sampling allows us to accelerate the calculation of the color CGHs. We compute diffraction calculations from the components, and then we convert the diffracted results in YCbCr color space to RGB color space.
Bending Moment Calculations for Piles Based on the Finite Element Method
Directory of Open Access Journals (Sweden)
Yu-xin Jie
2013-01-01
Full Text Available Using the finite element analysis program ABAQUS, a series of calculations on a cantilever beam, pile, and sheet pile wall were made to investigate the bending moment computational methods. The analyses demonstrated that the shear locking is not significant for the passive pile embedded in soil. Therefore, higher-order elements are not always necessary in the computation. The number of grids across the pile section is important for bending moment calculated with stress and less significant for that calculated with displacement. Although computing bending moment with displacement requires fewer grid numbers across the pile section, it sometimes results in variation of the results. For displacement calculation, a pile row can be suitably represented by an equivalent sheet pile wall, whereas the resulting bending moments may be different. Calculated results of bending moment may differ greatly with different grid partitions and computational methods. Therefore, a comparison of results is necessary when performing the analysis.
A Novel Technique to Calculate UV Opacity at Gale Crater from MSL/REMS Measurements
Vicente-Retortillo, Álvaro; Martínez, Germán M.; Renno, Nilton O.; Lemmon, Mark T.; Mason, Emily L.; de la Torre-Juárez, Manuel
2016-04-01
The Rover Environmental Monitoring Station (REMS) on board the Mars Science Laboratory (MSL) mission carries a UV sensor that for the first time is measuring the solar radiation at the surface of Mars in six bands between 200 and 380 nm [1]. Here we present a novel methodology to calculate the atmospheric opacity by using the UV photodiode output currents measured by this sensor (TELRDR products) and ancillary (ADR) data. We estimate the diffuse and total radiation signals by analyzing the events in which the direct solar beam was temporarily blocked by the masthead or by the mast of the rover. Then we use a radiative transfer model with updated radiative properties of the Martian aerosols ([2], [3]) based on the Monte-Carlo method to retrieve the UV opacity from those measurements. Therefore, this methodology is not sensitive to the degradation of the sensor due to the deposition of dust on it. In addition, by using TELRDR and ADR data, inconsistencies in the processed reduced data (ENVRDR and MODRDR products, in units of W/m2) found when the solar zenith angle relative to REMS rover frame is above 30° are avoided. In order to validate our technique, we compare the UV opacities with those derived from Mastcam observations at 880 nm. We find that both opacities show a good agreement and follow a similar seasonal trend, with the UV opacity showing values generally lower than at 880 nm. The difference between both opacities varies over the year, with the minimum difference occurring during the first half of the winter, when both opacities show their annual lowest values. The temporal variation of this difference may be used to analyze changes in the dust size distribution. [1] Gómez-Elvira, J., Armiens, C., Castañer, L., Domínguez, M., Genzer, M. et al. REMS: the environmental sensor suite for the Mars Science Laboratory rover. Space Sci. Rev., 170 (1-4), 583-640, 2012. [2] Vicente-Retortillo, A., Valero, F., Vázquez, L. and Martínez, G. M. A model to calculate
Calculation of brain atrophy using computed tomography and a new atrophy measurement tool
Bin Zahid, Abdullah; Mikheev, Artem; Yang, Andrew Il; Samadani, Uzma; Rusinek, Henry
2015-03-01
Purpose: To determine if brain atrophy can be calculated by performing volumetric analysis on conventional computed tomography (CT) scans in spite of relatively low contrast for this modality. Materials & Method: CTs for 73 patients from the local Veteran Affairs database were selected. Exclusion criteria: AD, NPH, tumor, and alcohol abuse. Protocol: conventional clinical acquisition (Toshiba; helical, 120 kVp, X-ray tube current 300mA, slice thickness 3-5mm). Locally developed, automatic algorithm was used to segment intracranial cavity (ICC) using (a) white matter seed (b) constrained growth, limited by inner skull layer and (c) topological connectivity. ICC was further segmented into CSF and brain parenchyma using a threshold of 16 Hu. Results: Age distribution: 25-95yrs; (Mean 67+/-17.5yrs.). Significant correlation was found between age and CSF/ICC(r=0.695, p<0.01 2-tailed). A quadratic model (y=0.06-0.001x+2.56x10-5x2 ; where y=CSF/ICC and x=age) was a better fit to data (r=0.716, p < 0.01). This is in agreement with MRI literature. For example, Smith et al. found annual CSF/ICC increase in 58 - 94.5 y.o. individuals to be 0.2%/year, whereas our data, restricted to the same age group yield 0.3%/year(0.2-0.4%/yrs. 95%C.I.). Slightly increased atrophy among elderly VA patients is attributable to the presence of other comorbidities. Conclusion: Brain atrophy can be reliably calculated using automated software and conventional CT. Compared to MRI, CT is more widely available, cheaper, and less affected by head motion due to ~100 times shorter scan time. Work is in progress to improve the precision of the measurements, possibly leading to assessment of longitudinal changes within the patient.