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The use of oscillometric methods to determine brachial blood pressure (bBP) can lead to a systematic underestimation of the invasively measured systolic (bSBP) and pulse (bPP) pressure levels, together with a significant overestimation of diastolic pressure (bDBP). Similarly, the agreement between brachial mean blood pressure (bMBP), invasively and non-invasively measured, can be affected by inaccurate estimations/assumptions. Despite several methodologies that can be applied to estimate bMBP non-invasively, there is no consensus on which approach leads to the most accurate estimation. Aims: to evaluate the association and agreement between: (1) non-invasive (oscillometry) and invasive bBP; (2) invasive bMBP, and bMBP (i) measured by oscillometry and (ii) calculated using six different equations; and (3) bSBP and bPP invasively and non-invasively obtained by applanation tonometry and employing different calibration methods. To this end, invasive aortic blood pressure and bBP (catheterization), and non-invasive bBP (oscillometry [Mobil-O-Graph] and brachial artery applanation tonometry [SphygmoCor]) were simultaneously obtained (34 subjects, 193 records). bMBP was calculated using different approaches. Results: (i) the agreement between invasive bBP and their respective non-invasive measurements (oscillometry) showed dependence on bBP levels (proportional error); (ii) among the different approaches used to obtain bMBP, the equation that includes a form factor equal to 33% (bMBP = bDBP + bPP/3) showed the best association with the invasive bMBP; (iii) the best approach to estimate invasive bSBP and bPP from tonometry recordings is based on the calibration scheme that employs oscillometric bMBP. On the contrary, the worst association between invasive and applanation tonometry-derived bBP levels was observed when the brachial pulse waveform was calibrated to bMBP quantified as bMBP = bDBP + bPP/3. Our study strongly emphasizes the need for methodological transparency and consensus for non-invasive bMBP assessment.

This paper presents a mechatronic platform consists of a stimulator and a prosthesis hand holder, which aims at extrinsic flexible tactile sensor calibration and performance test for prosthesis hand application. The former is driven by a linear motor and the latter is driven by the combination of one 3 dimensions of freedom (DoF) motion stage and two rotation stages. A procedure is developed to calibrate flexible tactile sensors attached on the anthropomorphic prosthetic hand, whose surface is curved. Although the flexible tactile sensors can be easily integrated on to the mentioned curved surface due to its flexibility and compliance, they are usually flat fabricated and characterized under the working of flat situation. Curved surface sensor characterization is not directly available from the manufacturer. Furthermore, when tactile sensors are applied, there would be an elastic layer covered on top for protection and improvement of grasping ability. This elastic material essentially deteriorates the characteristics of the sensor under it, which is another important reason for establishing a platform to re-calibrate tactile sensor mounted on prosthetic hand. In this paper, two kinds of commercial tactile sensors are involved which are force sensing resistor (FSR) representing static measurement sensor and polyvinylidene fluoride (PVDF) sensor representing dynamic measurement sensor where a rigid rod with polydimethylsiloxane (PDMS) covered imitates prosthetic finger. The methodology of calibration compares the measured data obtained from tactile sensor with the one from a load cell fixed on the stimulator. The procedure of receptive-field measurement for tactile sensor on the prosthetic hand is shown and the equation for estimating the position and amplitude of surface load on top of elastic cover is established. Different combinations of tactile sensors are implemented on the rigid substance and two motion patterns of stimulator are performed on them, which are indentation and sliding. The performance of developed platform is also analyzed and it shows the ability of testing flexible tactile sensor for prosthesis hand. [ABSTRACT FROM AUTHOR]

The paper proposes a method for reliable energy diagnoses, aimed at integrated design of energy refurbishment of existing buildings, with reference to historical architectures. The approach is structured according to three main phases: (a) the building performance assessment, by combining in situ monitoring and documental information; (b) the numerical studies by hourly energy simulations with a deepening about the calibration methodology; (c) the investigation of potential energy savings, environmental benefits and economical profitability of selected energy efficiency measures. The case study is an educational building of the University of Sannio, located in the ancient center of Benevento (Southern Italian city). The knowledge of the historical energy requests, combined with several measurements (e.g., schedules of indoor temperatures, activation of HVAC system) and with in situ investigation (e.g., infrared thermography and heat flow measures) allowed the calibration of the numerical model. Moreover, several actions for the energy rehabilitation have been implemented, by taking into account the historical value of the building and of its context. The achieved results show that the selection of the energy efficiency measures is a multi-objective optimization problem and – even if heritage buildings require respect of several constraints – however satisfactory energy savings are available. [ABSTRACT FROM AUTHOR]

A reliable and simple-to-use algorithm was developed for the energy-calibration of double-sided silicon strip detectors (DSSSDs). It works by enforcing mutual consistency of p-side and n-side information for every detected event. The procedure does not rely on a dedicated data set for calibration and is robust enough to work fully automated without human supervision. The method was developed and applied to data from a DSSSD of the Lund-York-Cologne CAlorimeter (LYCCA) for the HISPEC experiment at FAIR. It has been tested on ions in the A ≈ 90 mass range at energies of E kin ≈ 300 MeV / u . [ABSTRACT FROM AUTHOR]

A method and circuit for determination of the ratio error of an inductive autotransformer voltage divider having a 1:2 nominal ratio are shown in this paper. The circuit is used for measurement of a differential voltage between corresponding taps of the divider investigated and reference inductive divider based on which ratio error is determined. The distinguishing feature of the measuring method developed is the possibility of virtual reconstruction of the rated ratio value of a standard divider. Thus, during the measurement process, there is no need to use the standard divider; instead, a divider having the constant, unknown error is used. The proposed circuit can also measure the leakage impedance of divider windings when using the developed three-stage procedure of measurement. In this paper, the obtained measurement results of the ratio errors and winding leakage impedance for different divider load and in a wide frequency range are presented. [ABSTRACT FROM PUBLISHER]

Nowadays, studies related to the distribution of metallic elements in biological samples are one of the most important issues. There are many articles dedicated to specific analytical atomic spectrometry techniques used for mapping/(bio)imaging the metallic elements in various kinds of biological samples. However, in such literature, there is a lack of articles dedicated to reviewing calibration strategies, and their problems, nomenclature, definitions, ways and methods used to obtain quantitative distribution maps. The aim of this article was to characterize the analytical calibration in the (bio)imaging/mapping of the metallic elements in biological samples including (1) nomenclature; (2) definitions, and (3) selected and sophisticated, examples of calibration strategies with analytical calibration procedures applied in the different analytical methods currently used to study an element׳s distribution in biological samples/materials such as LA ICP-MS, SIMS, EDS, XRF and others. The main emphasis was placed on the procedures and methodology of the analytical calibration strategy. Additionally, the aim of this work is to systematize the nomenclature for the calibration terms: analytical calibration , analytical calibration method, analytical calibration procedure and analytical calibration strategy . The authors also want to popularize the division of calibration methods that are different than those hitherto used. This article is the first work in literature that refers to and emphasizes many different and complex aspects of analytical calibration problems in studies related to (bio)imaging/mapping metallic elements in different kinds of biological samples. [ABSTRACT FROM AUTHOR]

A particle-based numerical simulation procedure is presented for the generation and calibration of geogrid-stabilised soil on the basis of experimental data. The paper describes how to simulate a biaxial geogrid depending on a specific particle and parallel bond model. Numerical and experimental pull-out tests have been performed to reproduce the pull-out force-strain behaviour of a biaxial geogrid specimen embedded in granular material under special consideration of the grain-size distribution, initial relative density, normal stress state as well as sample installation. Model analysis of soil mobilisation and geogrid deformation is presented to understand the significance of the interlocking effect as key mechanism for soil stabilisation. The procedure can be used for further investigations of the influence and effects of soil stabilisation depending on the significant properties of the interacting components (soils and geogrids). [ABSTRACT FROM AUTHOR]

The International Temperature Scale of 1990 (ITS-90) defines exact values for all fixed-point temperatures. For example, for the standard platinum resistance thermometers (SPRT), at each fixed point, the measured SPRT resistance and the temperature defined in the ITS-90 are used as input data into the correction equations of the ITS-90. Starting from 2006, formal equations were added to the Technical Annex for the ITS-90 for computing the fixed-point temperatures of the substances of different isotopic compositions, presently the $$e\hbox {-H}_{2}$$ triple and vapor-pressure points, Ne triple point, and $$\hbox {H}_{2}\hbox {O}$$ triple point. This paper addresses the issue of the method required to apply the procedure defined in the ITS-90 for the calibration of a SPRT, according to the new requirements. The required procedure does not involve a 'correction' of the fixed-point temperatures, since they are defined exactly by the ITS-90, but requires instead, the re-computing of the measured resistances at the relevant fixed points. In those cases where resistance ratios with respect to the triple point of water are required, the re-computation must be first applied separately to the specific fixed points and to the triple point of water. In case the re-computation is not possible because of insufficient information on the isotopic composition of the sample used, an additional component must be added to the total uncertainty budget. [ABSTRACT FROM AUTHOR]

A computational and theoretical evaluation of the potential for calibration (verification) of critical micronozzles by the comparison method is performed by means of a micronozzle comparator. The operations of the technique of performing measurements with the use of this comparator are noted, the first results of studies are set forth, and a dependence for computational estimation of the error of measurements performed by means of this method are presented. [ABSTRACT FROM AUTHOR]

Abstract: Working in the low cost 3D scanner design domain, it would be very interesting to employ the inertial technologies because they could provide objects’ surface spatial data, recording their movements, and asking a very low cost in term of sensor investment. Unfortunately these technologies are characterized by distortion problems that normally do not allow to obtain satisfying measures for being employed for 3D scanning applications. This situation happens when working with Magnetic Angular Rate Gravity (MARG) sensor, on which many reports have been written to describe the methods used to suitably manage the data provided by the sensors in order to obtain an accurate orientation estimation; but only a few address the problem of calibration and distortion compensation. Furthermore, the proposed approaches usually involve both complex sensors models and accurate calibration facilities expensive from the workload, the computational and the economic points of view which compromise their possible employment in low-cost 3D scanning applications. In this paper, a novel approach for MARG sensors heading alignment and distortion compensation is proposed in order to increase the reliability of the information provided by the sensors and improve the process of attitude estimation, in order to get measurement quality level sufficient to be employable in 3D scanning applications. Both the effectivity and the reliability of the proposed approach are validated by some experimental results and the performances are evaluated considering the quality of the outcome provided by the same attitude estimation algorithm processing raw data and compensated data. [Copyright &y& Elsevier]

NOx reduction over an Fe–zeolite catalyst is simulated for highly transient conditions representative of automotive diesel engine operation. A transient 1D convection + 1D diffusion (1D + 1D) model for a single channel of a catalytic converter is developed, including a set of the most recently proposed kinetics for Fe–zeolite catalysts. The parameters specifying the characteristics of the selective catalytic reduction system are introduced, and an efficient calibration procedure is proposed that exploits the specific structure of the experimental dataset, consisting of a total of 90 operating conditions with varying space velocities, temperatures and inlet concentrations.Parameterization of the system is carried out by studying the system response to single step feeds in the inlet ammonia up to steady state (slow transient). Experimental data for highly dynamic ammonia dosing is subsequently employed to assess the model performance at highly transient conditions typical of diesel engine operation. Excellent agreement is reported for a total of 90 operating conditions; differences between the predictions and the experimental data in cumulative converted NOx after 20,000 s of operation are less than 2%. [ABSTRACT FROM AUTHOR]

Abstract: The limit of quantitation (LOQ) is a crucial parameter in quantitative analysis. Besides the classical “10 s B approach”, other concepts have been previously described based on the limitation resulting from the calibration procedure, namely from the prediction bands and the uncertainty calibration. Because of the difficulty of obtaining a reliable value of the blank standard deviation, this approach was replaced by the study of the %RSD of the net signal as a function of the concentration. Recently described, the so-called accuracy profile method, accuracy being the contribution of both the trueness and the precision, allows the analyst to define a validity domain, the lowest point acting as a limit of quantitation. The aim of this work was to determine these various limits of quantitation, including that from the accuracy profile, to compare them, and to study the parameters that can influence their values. It was concluded that the LOQ deduced from the accuracy profile is a realistic one. Its value is mainly influenced by the calibration procedure, particularly when a weighting procedure is used. A 1/y weighting factor, y being the analyte line intensity, seems to be an efficient compromise for calibration. [Copyright &y& Elsevier]

Abstract: In this paper a novel calibration procedure for the parameter determination of ion-selective electrodes used in an array is described. Commonly used procedures require a large number of standards to determine the parameters based on the Nicolsky–Eisenman model. The elaborated procedure reduces the number of standards to a minimum by using a standard containing a mixture of ions instead of a couple of pure standards. This paper presents a complete calibration procedure, which consists of designing the composition of the standards, parameter determination and verification of the calibration results. Comparison of the results obtained by the procedure presented with results obtained by the Two-Point Calibration and Separate Solution methods proves that the accuracies of both procedures are comparable. The outlined procedure can be applied in multicomponent analysers. [Copyright &y& Elsevier]

This work suggests a procedure to correctly calibrate the parameters of a one-dimensional MBBR dynamic model in nitrification treatment. The study deals with the MBBR configuration with two reactors in series, one for carbon treatment and the other for nitrogen treatment. Because of the influence of the first reactor on the second one, the approach needs a specific calibration strategy. Firstly, a comparison between measured values and simulated ones obtained with default parameters has been carried out. Simulated values of filtered COD, NH4-N and dissolved oxygen are underestimated and nitrates are overestimated compared with observed data. Thus, nitrifying rate and oxygen transfer into the biofilm are overvalued. Secondly, a sensitivity analysis was carried out for parameters and for COD fractionation. It revealed three classes of sensitive parameters: physical, diffusional and kinetic. Then a calibration protocol of the MBBR dynamic model was proposed. It was successfully tested on data recorded at a pilot-scale plant and a calibrated set of values was obtained for four parameters: the maximum biofilm thickness, the detachment rate, the maximum autotrophic growth rate and the oxygen transfer rate. [ABSTRACT FROM AUTHOR]

Calibration laboratories and national metrology institutes are commonly calibrating thermal imagers with equipment and procedures that were primarily developed for the calibration of optical radiation thermometers. This approach provides direct calibration results only for a small percentage of the detector elements, which are in view of a blackbody aperture. For the remaining detector elements of the thermal imager under calibration, it is assumed that they have the same characteristics. This inference may not be always true, so a new calibration procedure is presented, which evaluates not only the correction and uncertainty of the selected detector elements, but also the uniformity of all detector elements of the thermal imager. Uniformity evaluation is based on two different approaches for the evaluation of the entire field-of-view (FOV) of the thermal imager. The first approach consists of dividing the imager FOV into partial FOVs according to the available size of the blackbody aperture. Each of the partial FOVs is successively positioned in front of a blackbody aperture, and it is automatically assembled into a single result image. The idea of the second approach is to position all detector elements (entire FOV) at the same time in front of a large blackbody aperture. Experimental work and analysis of both approaches for the calibration procedure of thermal imagers are presented. [ABSTRACT FROM AUTHOR]

Abstract: Parameter estimation is an important preliminary step before using a crop model to evaluate the effect of different management strategies. This study compared three procedures for estimating parameters of the STICS soil–crop model. Two procedures estimate parameters using information on both dynamic and end-of-season variables. One of those procedures estimates parameters in successive estimation steps, whereas the other estimates many parameters simultaneously in a single step. The third procedure uses only information on end-of-season variables. In all cases, the parameter values were constrained to lie within the same bounds, which represent physiologically reasonable values. Data from 235 and 138 experimental plots were used for parameter estimation and independent model evaluation, respectively. Mean squared error of adjustment and of prediction were analysed to evaluate the performance of the different procedures. An agronomic analysis was conducted to evaluate the capacity of the model to respond to varying fertilisation strategies. The results indicate that using information from dynamic variables is not useful if the only objective is to improve model prediction of end-of season variables. However, to improve model prediction of both dynamic and end-of-season variables, all information should be used. In this case, better results were obtained when all dynamic variables were used in a single estimation step. This study provides some methodological guidelines on running parameter estimation for complex crop models. Our results also indicate that parameter estimation can highlight problems of process representation in a crop model. [Copyright &y& Elsevier]

particle based numerical simulation procedure is presented, which allows the reproduction of the stress-strain characteristics of stiff granular material (ballast or gravel) under quite different loading conditions. If grain-shape, grain-size and relative density is considered in a proper manner, a relatively simple constitutive law with only three constants (friction coefficient, shear and normal stiffness) is sufficient for the reproduction of the observed stress-deformation behaviour. The paper describes the procedures, how to get information about grain-shape and size and how to generate samples with realistic grain-shape, size and relative density under the pre-requisite to optimize the computational effort. The procedure was successfully tested using five different lab test: soil-dump test, soil-pouring test, oedometer test, triaxial test and multi-stage shear test, also under consideration of different initial densities. [ABSTRACT FROM AUTHOR]

method of estimating the uncertainty of the measurement of temperature in the working range of a platinum resistance thermometer, taking into account the correlation of the uncertainties of a check of the thermometer at fixed points, is considered. It is shown that, in the case when the overall correlation uncertainties exceed the uncorrelated uncertainties, one can use linear interpolation to calculate the measurement uncertainty. A method of reducing the uncertainty of the measurement of temperature difference using two thermometers, calibrated using the same apparatus, taking the correlation of the input quantities in account, is proposed. [ABSTRACT FROM AUTHOR]

A technique for using a receive signal strength indicator to measure the total isotropic sensitivity of a wireless handset is proposed in this paper. This technique separates the measurements of the mobile station radiated sensitivity and its receive antenna gain. A single measurement of the mobile station radiated sensitivity is performed while the mobile station antenna gain is obtained through the receive signal strength indicator. Hence, a significant reduction in measurement time can be achieved. The fundamental theory for the method is described. Techniques for reducing the ±2 dB error in the receive signal strength indicator reporting system and the improvement of the measurement resolution are developed. Overall, this technique can reduce measurement time by a significant factor and also improve measurement accuracy over the conventional measurement approach. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, the experimental thermodynamic characterization of solvents in an extended range of temperatures and pressures is essential for the development of a wide variety of industrial applications (refrigeration, reactors, pumping, etc.). Moreover, accurate experimental data are also the key for the successful development and subsequent benchmarking of thermodynamic theoretical models. In the particular case of isobaric heat capacities, there are quite a lot of reported experimental high temperature data but, on the other hand, low temperature data are practically inexistent for most compounds. Bearing this limitation in mind, the present work is focused on the development of a new calibration methodology for calorimetric determination of isobaric heat capacities in liquid state at low temperatures. For this purpose, a Calvet calorimeter, SETARAM BT 2.15 has been used. By means of the calibration procedure explained below, this calorimeter allows to determine phase transitions and thermodynamic properties in a wide range of temperature (233.15–473.15K) and pressure (0.1–100MPa). [ABSTRACT FROM AUTHOR]

Electric energy meters have always been designed to account energy under sinusoidal conditions, and therefore, the uncertainty specification outside these conditions was of little interest. This was considered acceptable when the voltage and current distortion level was low and the old well-known induction meters were used. In fact, under these conditions, the measurement errors caused by distortion did not generally penalize the customers. The present situation is, however, quite different: Distortion is not any longer negligible, particularly in low-voltage systems, and the modern electronic energy meters can be much more sensitive to distortion than the induction meters, depending on the implemented measurement algorithm. This paper briefly discusses the calibration problems raised by the electronic energy meters and proposes a new calibration procedure, fully compliant with the recent Directive of the European Parliament on the measuring instruments, and based on a synthesizer of randomly distorted signals, capable of evaluating the measurement uncertainty of the energy meters under the distorted conditions that are likely to be met in their normal operating conditions. [ABSTRACT FROM AUTHOR]

When using spherical elements within the Discrete Element Method, computational costs can be kept low even for large numbers of elements. However, this oversimplification of the granular geometry has drawbacks when quantitatively assessing the model even for frictional geomaterials. To overcome this limitation, the local constitutive law must at least take into account the transfer of a moment between elements. This moment, which is added to normal and shear local interaction forces, increases the number of local parameters. Moreover, when local plastic thresholds are considered, the calibration of the model becomes tricky. With such a set of local parameters, a calibration procedure is proposed, which attempts to define the respective role of each parameter in the macroscopic behavior. A series of numerical simulations of triaxial compression tests has been performed to check the capability of this model to get good quantitative results and the incremental behavior of the numerical medium is studied by performing a series of axisymmetric stress probes with varying directions. The corresponding strain responses are measured. From different initial stress states, the results indicate that the incremental response is well described by elastoplasticity with a single mechanism, and a non-associative flow rule. [ABSTRACT FROM AUTHOR]

• Uncertainty budget of a high precision telescopic instrument for simultaneous multilateration • Novel high precision instrument calibration model for simultaneous multilateration • Uncertainty of the simultaneous multilateration process in workshop conditions • Quality requirements definition from Monte Carlo method The precision manufacturing industry depends on precision measurement instruments capable of tracing the measurement results to national and international standards. This paper presents a calibration model for a high precision telescopic instrument (HPTI) for machine tool verification together with its estimated uncertainty budget. The instrument tracks autonomously a target using an interferometric sensor to measure distances and allows the simultaneous use of three HPTIs for multilateration, decreasing data capture time and improving measurement accuracy. A calibrating ball beam artefact, previously calibrated with a coordinate measurement machine, is used to trace the calibration results. The uncertainty of the HPTI is estimated in laboratory conditions. The uncertainty budget of the HPTI, as well as the uncertainty of simultaneous multilateration, in workshop conditions are analysed and estimated with Monte Carlo. The calibration model defined gives traceability to the measurement results obtained with the HPTI allowing its use in machine tool verification processes. [ABSTRACT FROM AUTHOR]

Abstract: A new calibration method for process analyzers, which requires a chemometric model, is presented. Instead of a huge amount of calibration data, which are usually necessary to calculate a chemometric model, just a single off-line sample is necessary for the proposed procedure. The further required information to calculate the chemometric model is made available in a form of a theoretical process model, whose parameter values will be estimated inherently during the calibration procedure. The functioning of the new procedure is demonstrated by its application to 2D-fluorescence data for the monitoring of a biotransformation process. In the process acetophenone is converted to (S)-1-phenylethanol. Using the new calibration method the relative errors of prediction of the substrate and product concentrations are 4.9% and 4.6%, respectively. [Copyright &y& Elsevier]

A methodology has been developed for indirect, noncontact, and dynamic sensing of angles for robotic applications. Two accelerometers are placed on the adjacent links close to the joint axis, and their outputs are processed to estimate the joint angle. In the proposed technique, the joint angles are obtained without integrating the accelerometer outputs. To ensure accuracy of accelerometer readings, two calibration procedures for the accelerometers are presented, which can easily be implemented in place. Both these methods solve a nonlinear least squares problem to adjust the offset parameters of the accelerometers. The accelerometer-based angle sensor is particularly suitable for the harsh working environment of heavy-duty manipulators, where conventional contact-type angle sensors cannot be deployed or problems are associated with their use. The performance of the new sensor is studied and compared with the performance of digital resolvers in two applications, involving the position control and dynamic payload measurement of a miniexcavator. The experimental results attest to the efficiency and accuracy of the new angle-sensing mechanism. [ABSTRACT FROM PUBLISHER]

This work deals with the methodology put in place to fit and validate the parameters of a biofiltration model (BAF) in tertiary nitrification treatment and dynamic conditions. For an average loading rate of 0.65 kg NH4-N/m³ media/d, different time loading rates are applied inside a filtration-backwash run using a semi-industrial pilot. Comparisons between predicted and observed values on the NH4-N, NO3-N and TSS in treated water and the total head loss ΔP are carried out firstly using default values of BAF parameters. Model predictions overestimate values measured but trends are well reproduced. A sensitivity analysis is carried out and the hierarchy of BAF parameters has been set up classifying them into strong and low influence on the effluent concentrations. Among parameters revealing the strongest influence are those of the filtration module and the mean density of biofilm for the TSS effluent and the total ΔP, the specific autotrophic growth rate, the maximum biofilm thickness and the reduction coefficient of diffusivity in the biofilm for the NH4-N, NO3-N effluent. Finally, this classification leads to setting a calibration procedure, thanks to specific experimental tests directly measuring some BAF parameters. [ABSTRACT FROM AUTHOR]

The static characteristics of platinum resistance thermometers with different platinum purities were measured. It is shown that in the 0–420°C range the ITS-90 method gives an error of less than 0.01°C, while in the 0–230°C range the error is less than 0.006°C. [ABSTRACT FROM AUTHOR]

Different systems of motion analysis have been described. They usually associate several cameras with a force platform. They can analyze very sophisticated human movements. They are, however, expensive and require significant technical formation from users. A new system is proposed for simple and standard clinical applications. It uses only two cameras and a coupled force plate delivering only the vertical component of the patient weight and the location of his center of mass. It is inexpensive, simple to use and delivers accurate results. This is obtained through a strict experimental protocol, and a new method of data treatment which allows the control of errors at each step of the successive calculations. This paper describes the new system, the new calibration procedure and the control of errors. [ABSTRACT FROM AUTHOR]

The structure of the 3-PG model is outlined indicating the input data and parameter values required to run it and the changes introduced since the model description was originally published. Calibration procedures are described and the capacity of 3-PG to fit a wide range of forest growth data sets, from experimental and commercial plantings, is evaluated. The data came from the environmental range from sub-tropical Africa and Australia (Kwa-Zulu Natal 28°S and Queensland) to northern Europe (Flakaliden, 64°N, in Sweden). In all cases it was possible to simulate the observed data with useful accuracy. Values of the key parameters, and the way they vary are provided. To test whether the model can predict stand growth when it has not been fitted to the data we used independent sets of measurements, providing tests of model performance at three levels of severity: a test against data from the same site, where different treatments were applied; a test on data from a different location, where a similar experiment had been carried out; and a test against data from a spacing and thinning experiment. The results of the tests are assessed in terms of simple statistics (r2 and bias). In the first and second tests, the r2 values were all >0.9 (with one exception, where r2=0.85), although the bias in some of the results for the first test was relatively high (>20% in above-ground and >50% in below-ground variables). The second test produced unbiased results; r2 values in the third test were lower, but the results were also essentially unbiased. The results presented show that the 3-PG model is robust and reliable and can be used with confidence to predict growth in areas where trees have not been grown, i.e. the model can be used to estimate site productivity. The model can also be used to explore the effects of environmental conditions on tree growth and productivity. Parameters in 3-PG that allow the model to account for species differences, and the problem of determining the appropriate values for the fertility rating used in the model are discussed. [Copyright &y& Elsevier]

We explore the breakdown of universal mobility behavior in sub-100-nm Si MOSFETs, using a novel three-dimensional (3-D) statistical simulation approach. In this approach, carrier trajectories in the bulk are treated via 3-D Brownian dynamics, while the carrier-interface roughness scattering is treated using a novel empirical model. Owing to the high efficiency of the transport kernel, effective mobility in 3-D MOSFETs with realistic Si-SiO2 interfaces reconstructed from a Gaussian or exponential correlation function can be simulated in a statistical manner. We first demonstrate a practical calibration procedure for the interface mobility and affirm the universal behavior in the long channel limit. Next, effective mobility in ensembles of MOSFETs with a gate length down to 10 nm is investigated. It is found that the random-discrete nature of the Si-SiO2 interface leads to a distribution of carrier mobility below the interface, which can deviate considerably from universal mobility curves when Lgate<6Λ, where Λ is the correlation length for the SiO2 interface. [ABSTRACT FROM PUBLISHER]