According to spatial models of political competition, parties strategically adjust their ideological positions to movements made by rival parties. Spatial econometric techniques have been proposed to empirically model such interdependencies and to closely convert theoretical expectations into statistical models. Yet, these models often ignore that the parties’ ideological positions are latent variables and, as such, accompanied by a quantifiable amount of uncertainty. As a result, the implausible assumption of perfectly measured covariates impedes a proper evaluation of theoretical propositions. In order to bridge this gap between theory and empirics, the present work combines a spatial econometric model and a Bayesian dynamic item response model. The proposed model accurately accounts for measurement uncertainty and simultaneously estimates the parties’ ideological positions and their spatial interdependencies. To verify the model’s utility, I apply it to recorded votes from the sixteen German state legislatures in the period from 1988 to 2016. While exhibiting a notable degree of ideological mobility, the results indicate only moderate spatial dependencies among parties of the same party family. More importantly, the analysis illustrates how measurement uncertainty can lead to substantively different results which stresses the importance of appropriately incorporating theoretical expectations into statistical models.

Laser triangulation is widely used to measure three-dimensional structure of surfaces. The technique is suitable for macroscopic and microscopic surface measurements. In this paper, the measurement uncertainty of laser triangulation is investigated on technical surfaces for microscopic measurement applications. Properties of technical surfaces are, for example, reflectivity, surface roughness, and the presence of scratches and pores. These properties are more influential in the microscopic laser triangulation than in the macroscopic one. In the Introduction section of this paper, the measurement uncertainty of laser triangulation is experimentally investigated for 13 different specimens. The measurements were carried out with and without a laser speckle reducer. In the Materials and Methods section of this paper, the surfaces of the 13 specimens are characterized in order to be able to find correlations between the surface properties and the measurement uncertainty. The last section of this paper describes simulations of the measurement uncertainty, which allow for the calculation of the measurement uncertainty with only one source of uncertainty present. The considerations in this paper allow for the assessment of the measurement uncertainty of laser triangulation on any technical surface when some surface properties, such as roughness, are known.

The development of evaluation methods for precision measurement and inter-verificationinterval measurement for measurement devices based on the concept of the uncertainty ofmeasurement is needed in order to establish the timing of the next scheduled orunscheduled verification of the correspondence of metrological characteristics to theirstandardised values. The definition of the timing (periodicity) of the metrologicalverification of measurement devices as used in business or health care, while monitoringenvironmental conditions and proving health and safety at work, is an urgent issue inscientific research, upon which depends the quality of goods and services. A method ofevaluating the accuracy of measurements and the inter-verification interval formeasurement devices is proposed, based on using international standards guidelines forquality measurement. The calibration method for evaluating the inter-verification intervalof measurement devices was tested during the metrological certification of the measurementdevice for the moment of inertia of electric motors.

A free-space transmission method has been used for reliable shielding effectivenessmeasurement of the easily available textile materials. Textiles with three different yarndensities were studied for their shielding effectiveness with the help of a vector networkanalyzer and laboratory calibrated two X-band horn antennas. The expressions ofuncertainty estimation have been derived in accordance with the present free-spacemeasurement setup for the calculated SE values. The measurements have shown that anelectromagnetic energy can be maximum shielded up to 16.24 dB with measurement uncertaintyless than 0.21 dB in 8.2 to 12.4 GHz range by a 160.85 μm textile. Thus,a thin textile with a high density can have higher shielding and this property mainlydepends on its intrinsic structure, frequency range and thickness. This study promises thepotential applications of such materials as a very cost effective shielding material atmicrowave frequencies with some modifications.

Civil engineering is a branch of science that covers a broad range of areas where experimental procedures often plays an important role. The research in this field is usually supported by experimental structures able to test physical and mathematical models and to provide measurement results with acceptable accuracy. To assure measurement quality, a metrology probabilistic approach can provide valuable mathematical and computational tools especially suited to the study, evaluation and improvement of measurement processes in its different components (modeling, instrumentation performance, data processing, data validation and traceability), emphasizing measurement uncertainty evaluation as a tool to the analysis of results and to promote the quality and capacity associated with decision-making. This paper presents some of the research held by the metrology division of the Portuguese civil engineering research institutes, focused on the contribution of measurement uncertainty studies to a variety of frameworks, such as testing for metrological characterization and physical and mathematical modeling. Experimental data will be used to illustrate practical cases.

Evaluation of geometric deviations for the purpose of determining compliance with specified form tolerances requires the acquisition of numerous measured data points and extensive computation to accurately characterize the inspected part’s geometry. If there are not enough data points measured or when the measured points are not distributed properly on the measured surface a high level of uncertainty in characterizing the inspected part’s geometry can be expected. However, increasing the number of data point also significantly increases the computational time and also increases computational uncertainty by adding to instability of the optimization process required to find the minimum deviation zone. Selections of number and location of the measured date points need to be performed by understanding the significance of these two sources of uncertainties. This paper discussed the effect of sampling procedure on uncertainty and precision of flatness inspection.

Nine european national metrology institutes (NMIs) are collaborating in a new project funded by the european metrology research programme (EMRP) to establish traceable dynamic measurement of the mechanical quantities force, pressure, and torque. The aim of this joint research project (JRP) is to develop appropriate calibration methods, mathematical models, and uncertainty evaluation. The duration of the project is 3 years for a global amount of €3.6 million. It began in September 2011.

The Guide to the expression of measurement uncertainty, (GUM, JCGM 100)and its Supplement 1: propagation of distributions by a Monte Carlomethod, (GUMS1, JCGM 101) are two of the most widely used documents concerningmeasurement uncertainty evaluation in metrology. Both documents describe three phases (a)the construction of a measurement model, (b) the assignment of probability distributionsto quantities, and (c) a computational phase that specifies the distribution for thequantity of interest, the measurand. The two approaches described in these two documentsagree in the first two phases but employ different computational approaches, with the GUMusing linearisations to simplify the calculations. Recent years have seen an increasinginterest in using Bayesian approaches to evaluating measurement uncertainty. The Bayesianapproach in general differs in the assignment of the probability distributions and itscomputational phase usually requires Markov chain Monte Carlo (MCMC) approaches. In thispaper, we summarise the three approaches to evaluating measurement uncertainty and showhow we can regard the GUM and GUMS1 as providing approximate solutions to the Bayesianapproach. These approximations can be used to design effective MCMC algorithms.

Today’s global economy obliges manufacturers to produce their products in high quality with cheaper cost. Thus, manufacturers must develop their products applying tests to get better performance and higher quality before distributing them to the competitive market. In order to produce long working life of transformer reactors without losing their performance, different tests including axial and flexural testing are applied on the cellulose based laminated board material used in production. During development of laminated board material, test results should be known very well and the measurement uncertainty of tensile tests should be calculated taking into account all parameters. In this study, effective parameters on the quality of tensile testing causing an increase on the measurement uncertainty are investigated. Tensile strength and elongation test of laminated board material were carried out according to IEC 60641-2 and the uncertainty contributions based on experimental results were calculated. The results and impact of the uncertainty parameters are presented in detail.

Computed tomography has entered the industrial world in 1980’s as a technique fornon-destructive testing and has nowadays become a revolutionary tool for dimensionalmetrology, suitable for actual/nominal comparison and verification of geometrical anddimensional tolerances. This paper evaluates measurement results using different measuringstrategies applied in different inspection software packages for volume and surface dataanalysis. The strategy influence is determined by calculating the measurement uncertainty.This investigation includes measurements of two industrial items, an aluminium pipeconnector and a plastic toggle, a hearing aid component. These are measured using acommercial CT scanner. Traceability is transferred using tactile and optical coordinatemeasuring machines, which are used to produce reference measurements. Results show thatmeasurements of diameter for both parts resulted in smaller systematic errors compared todistance and height measurements. It was found that uncertainties of all measurandsevaluated on surface data were generally greater compared to measurements performed onvolume data.

This paper proposes a bootstrap approach to determine the measurement uncertainty of measurement devices with unknown measurement equation (in this work, a structured light projection system is applied for the measurement of pull broaches) by use of workpieces that are calibrated by a coordinate measuring machine (CMM). The obtained uncertainty is used to perform a conformance assessment of the initial measurement process according to ISO 14253-1 and VDA 5.

We propose an image-based framework to evaluate the uncertainty in the estimation of the volume fraction of specific microstructures based on the observation of a single section. These microstructures consist of cubes organized on a cubic mesh, such as monocrystalline nickel base superalloys. The framework is twofold: a model-based stereological analysis allows relating two-dimensional image observations to three-dimensional microstructure features, and a spatial statistical analysis allows computing approximate confidence bounds while assessing the representativeness of the image. The reliability of the method is assessed on synthetic models. Volume fraction estimation variances and approximate confidence intervals are computed on real superalloy images in the context of material characterization.