We suggest and use a test for evaluation of the accuracy of the harmonic coefficients in the Earth gravity field models (EMs), in which just the harmonics of the order mmin ≤ mm ≤ mmax and degree m ≤ 1 ≤ 1max are selected from the whole EMs. These parts will be called "frequency window(s)" (FWs). We treat the FWs of various recent EMs. One FW has been constructed solely from the resonant results for 12 ≤ m ≤ 15; we call it RFW. This RFW is used as a standard, sometimes independent, for comparing and testing other FWs. By means of the FWs, radius-vectors of the relevant parts of gecid are determined and compared to those of RFW. We intend to evaluate the differences between the EMs and to distinguish the models, FWs differ significantly from the RWF. and Celý článek bude publikován v Bull. Astron. Instit., sv..1985
Problems related to accuracy of tilt measurements realized during experimental studies of miniature tilt sensors (including MEMS devices) are minutely discussed. The measurements are performed by means of a custom computer controlled test rig, over the full range of pitch and roll. Accuracy of the test rig is determined in terms of uncertainty of the measurements involved. Ways of improving performance of the test rig are briefly introduced. Exemplary results of experimental works are presented. and Obsahuje seznam literatury
Precise relative gravimeters achieve the internal precision about a few μGal 1, even in field conditions. Nevertheless this precision is in fact concerned with the instant of measurement and can not be confused with the accuracy of the gravity at the gravity station, which is influenced by other effects. The best approach of these two values is question of high-quality elimination of instrumental errors and time-variable disturbing effects affecting the relative gravity measurements., Martin Lederer., and Obsahuje bibliografii
An analytical method od determination of luni-solat perturbations of the satellite motion is described here. The motion of perturbing body is described by trigonometrical series with the necessary accuracy. The determination of perturbations is made by numerous analytical transformations of the series by means of computer. As a result of these transformations the original accuracy is lost because of the limitation of the number of terms in series. The loss of accuracy is subjected to analysis by means of numerical tests and intotal accuracy of original series is estimated for fixed required accuracy of the calcualtion of satellite coordinates.
Software measurements provide developers and software managers with information on various aspects of software systems, such as effectiveness, functionality, maintainability, or the effort and cost needed to develop a software system. Based on collected data, models capturing some aspects of software development process can be constructed. A good model should allow software professionals to not only evaluate current or completed projects but also predict future projects with an acceptable degree of accuracy.
Artificial neural networks employ a parallel distributed processing paradigm for learning of system and data behavior. Some network models, such as multilayer perceptrons, can be used to build models with universal approximation capabilities. This paper describes an application in which neural networks are used to capture the behavior of several sets of software development related data. The goal of the experiment is to gain an insight into the modeling of software data, and to evaluate the quality of available data sets and some existing conventional models.
Clays (2005) and the Handbook of Clay Science (2006) are new textbooks. Clays, written by Alain Meunier, is for those studying earth sciences. The Handbook of Clay Science, edited by Faїza Bergaya, Benny Theng and Gerhard Lagaly, is concerned particularly with the industrial application of clay mineral science. Both books ar e timely and could fill important gaps in the library of mineral science. Their quality as textbooks is discussed. Critical an alysis of editorial accuracy, indexes and user-friendliness indic ate that both books fall short of the high standards that should be the hallmark of academic publication. Their shortcomings seem to be related to widespread problems that may beset commercial publica tion of scientific books., Christopher V. Jeans., and Obsahuje bibliografické odkazy
We investigated how the sampling process of microhistological faeces analysis could be optimised for an accurate estimation. Spring diet composition of European hare (Lepus europaeus Pallas, 1778) was determined in a juniper shrubland at Bugac, Hungary. Both inter and intraobserver reliability was high permitting us to separate the components of variance due to the methodological steps in the faeces analysis. Estimates varied depending on the number of independent droppings, pellets/individual, subsamples/pellet and epidermis/subsample. The variance was much higher among than within the independent pellet groups. The cumulative frequency estimate stabilised at around 100 epidermis fragments per pellet. We conclude that the most critical steps of the sampling procedure are the collection of independent droppings and the identification of a sufficient number of epidermis fragments. We propose to collect at least 10 independent droppings, one pellet/individual, and analyse 100 epidermis fragments as an optimum for estimating the relative frequency of forage classes reliably. The importance of the individual variability in the diet should be emphasised.
Digitization of periosteal and endosteal contours of bone cross section is one of several methods used for calculating long bone cross-sectional geometry (CSG). In this study, invasively obtained bone histological samples were used to calculate intra-observer measurement error for CSG parameters. Intra-observer error was measured based upon repeated measurements of cross-sectional areas (total area [TA], cortical area [CA]) and moments of area (Imax, Imin, Imax/Imin, J) in B6CBA mice (n = 17). Cross sections were cut at 50 % of the biomechanical length of the left tibia and the samples were further processed for CSG and histological analysis. Intra-observer error was measured to estimate the accuracy of the digitization method. Accuracy of the tested digitization method was expressed by mean difference (MD), mean absolute difference (MAD), and limits of agreement (LA). The results confirm our assumption that intra-observer error decreases with the number of repeated measurement events. Thus, the error can be minimized by acquiring experience in the section digitizing. Our results also show that TA, CA and polar moment of area (J) are more susceptible to intra-observer error than are Imax, Imin and Imax/Imin.
This project deals with calibration of experimental texturemetre at tensile and compressive loading. We have used the samples of European walnuts for the etalon calibration. We tested compressive loading and on the walnut. Measurements was realised on Stentor Andilog 1000 and on the developed texturemetre. These equipment recorded force and displacement. We could use those data, which were gathered to create dependencies of every device. We created correlations for each measurement. Also we could determine the accuracy of the equipments with apply of the coefficient of correlation. We could determine the linearity of the equipment with the help of the regression method. and Táto práca sa zaoberá kalibráciou vývojového textúrometra pri zaťažení materiálu tlakom. Pre dosiahnutie kalibrácie boli merané vzorky orecha vlašského zaťažené na tlak. Merania boli realizované na zariadení Stentor Andilog 1000 a na vývojovej trhačke. Prístroje zaznamenávali silu a premiestnenie. Z týchto údajov potom boli zostrojené grafické závislosti. Boli vytvorené korelačné tabuľky pre jednotlivé merania. Pomocou koeficientu korelácie sme zistili, že meracie zariadenia sú s vysokou pravdepodobnosťou zhodné. Pomocou regresnej metódy bolo dokázané, že existuje nelinearita pri vyššom zaťažení.
The definition of the performance parameters, especially accuracy, reliability, dependability are presented. Their estimations are developed by using results from the theory of statistical tolerance intervals in the case of random sample from a normal distribution. The proposed approach is illustrated on two examples.