Relevant bibliographies by topics / Accuracy problems; Geometric errors

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Accuracy problems; Geometric errors'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Accuracy problems; Geometric errors"

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Базров, Борис, and Boris Bazrov. "Problems in estimate of parts geometrical accuracy." Science intensive technologies in mechanical engineering 2018, no. 4 (2018): 8–12. http://dx.doi.org/10.12737/article_5aacd85793bdc2.44830790.

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The paper reports the analysis of the method for parts geometrical accuracy definition which includes the following stages: part surfaces measurement, a representation of measurement results and their relative position, a definition without errors count and a definition of surface errors. There are shown drawbacks of stages enumerated such as a neglect of measurement base surface errors, an ambiguity of measurement base positions regarding surfaces under control, use of bases of error account and criteria for errors estimate irrespective of surface operation functions.
 A multi-gradation
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Yang, Hongtao, Mei Shen, Li Li, Yu Zhang, Qun Ma, and Mengyao Zhang. "New identification method for computer numerical control geometric errors." Measurement and Control 54, no. 5-6 (2021): 1055–67. http://dx.doi.org/10.1177/00202940211010835.

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To address the problems of the low accuracy of geometric error identification and incomplete identification results of the linear axis detection of computer numerical control (CNC) machine tools, a new 21-item geometric error identification method based on double ball-bar measurement was proposed. The model between the double ball-bar reading and the geometric error term in each plane was obtained according to the three-plane arc trajectory measurement. The mathematical model of geometric error components of CNC machine tools is established, and the error fitting coefficients are solved throug
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Mikó, Balázs, Bálint Varga, and Wojciech Zębala. "The Effect of the Feed Direction on the Micro- and Macro Accuracy of 3D Ball-end Milling of Chromium-Molybdenum Alloy Steel." Materials 12, no. 24 (2019): 4038. http://dx.doi.org/10.3390/ma12244038.

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The machining of free form surfaces is one of the most challenging problems in the field of metal cutting technology. The produced part and machining process should satisfy the working, accuracy, and financial requirements. The accuracy can describe dimensional, geometrical, and surface roughness parameters. In the current article, three of them are investigated in the case of the ball-end milling of a convex and concave cylindrical surface form 42CrMo4 steel alloy. The effect of the tool path direction is investigated and the other cutting parameters are constant. The surface roughness and th
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Zhao, Wu, and Guo Ji Wang. "Analysis Geometric Precision of Workpiece and Geometric Errors Model of 5-Axis Machining Center for Processing Turbo Molecular Pump Rotor." Advanced Materials Research 305 (July 2011): 423–27. http://dx.doi.org/10.4028/www.scientific.net/amr.305.423.

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The research investigates two kinds basic problems during the precision processing about turbo molecular pump rotor using 5-axis machining center. The one is to study the geometric and dimensional precision of turbo molecular pump rotor. The other one is to study the accuracy evaluative factors of 5-axis turbo molecular pump rotor machining center. For improving the processing precision to ensure the dynamic symmetry and geometric symmetry of the turbo molecular pump rotor, it focus on analyzing the allowable deviations from the turbo molecular pump rotor’s nominal geometry and dimensions spec
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Петрунин, В., V. Petrunin, О. Казакова, O. Kazakova, А. Казаков, and A. Kazakov. "Improving of accuracy at billet processing in CNC machines." Science intensive technologies in mechanical engineering 1, no. 2 (2016): 44–48. http://dx.doi.org/10.12737/17809.

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The problems of accuracy improvement at billet processing withemphasison the influence degree of errors in tool holder geometric forms on the accuracy of the in-line arrangement and tangent stiffness atfixing in a machine spindle are considered. The most frequent cases of form errors, occurring at the tool holders production, are considered: circular deviation (particularly occurrence of out-of-roundness in cross-sectional view), deviations of straightness of cone generatrix (bulge, incurvature), angular errors. To evaluate the accuracy of the in-line arrangement and rigidity of corners of the
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Anikeeva, Olesya, Alexander Ivakhnenko, and Oleg Erenkov. "Approaches to nonlinear theory creation for machine tools geometric accuracy." MATEC Web of Conferences 224 (2018): 01037. http://dx.doi.org/10.1051/matecconf/201822401037.

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The justification of the nonlinear theory creation in machines geometrical accuracy field is given in the work. The problems accountings of which don’t allow providing the consecutive linearization method adequacy at geometrical accuracy calculating of metal-cutting machines are considered. The potential sources of not linearities at calculating of metal-cutting systems accuracy and the sources of the nonlinear members appearance are revealed. At the same time the nonlinear members are considering the machines geometrical errors at a shaping function variation. The full variation of shaping fu
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Jha, Navnit, R. K. Mohanty, and Vinod Chauhan. "The Convergence of Geometric Mesh Cubic Spline Finite Difference Scheme for Nonlinear Higher Order Two-Point Boundary Value Problems." International Journal of Computational Mathematics 2014 (July 23, 2014): 1–12. http://dx.doi.org/10.1155/2014/527924.

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An efficient algorithm for the numerical solution of higher (even) orders two-point nonlinear boundary value problems has been developed. The method is third order accurate and applicable to both singular and nonsingular cases. We have used cubic spline polynomial basis and geometric mesh finite difference technique for the generation of this new scheme. The irreducibility and monotone property of the iteration matrix have been established and the convergence analysis of the proposed method has been discussed. Some numerical experiments have been carried out to demonstrate the computational ef
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LUO, YUNHUA, and ARVIND SHAH. "A GENETIC ALGORITHM BASED PROCEDURE FOR AUTOMATIC CRACK PROFILE IDENTIFICATION." International Journal of Computational Methods 02, no. 03 (2005): 401–17. http://dx.doi.org/10.1142/s0219876205000557.

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This paper presents a genetic algorithm based procedure for automatic identification of crack profiles. In the procedure geometric modeling technique is applied to incorporate crack(s) into the structure under evaluation and a geometric model is generated. The geometric model is then used to generate finite element mesh. In solving forward problems, finite element meshes are adapted based on error estimation to improve accuracy in computed structural responses. Numerical results show that error from solving forward problems can largely slow down GA convergence and significantly affect the accu
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Zhao, Dongzhuo, Zhan Wang, Jianrong Pan, and Peng Wang. "Error Analysis Method of Geometrically Incomplete Similarity of End-Plate Connection Based on Linear Regression." Applied Sciences 10, no. 14 (2020): 4812. http://dx.doi.org/10.3390/app10144812.

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Due to the limitations of processing errors, test conditions and other factors, geometric similarity errors in scale tests of steel structure joints are difficult to avoid, but the research on this error is little known. Based on the similarity theory and the basic idea of the component method, this paper deduces the similar macro conditions of beam–column end-plate connections and derives the main influencing factors of geometric similarity of these types of structures. Aiming at the factor of the thickness of the end-plate, the formation mechanism of the geometrically incomplete similarity e
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Neelov, V. V., and S. E. Shaldaev. "Influence of accuracy estimation of frequency characteristics of radar targets on the results of identifying the geometric shape of local reflectors." Izmeritel`naya Tekhnika, no. 7 (2020): 56–61. http://dx.doi.org/10.32446/0368-1025it.2020-7-56-61.

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The issues of introducing broadband technologies in civil and special purpose radar systems are considered. The popularity of these technologies for solving a number of practical problems determines the relevance of research related to a detailed analysis of long-range portraits of observed objects at a new qualitative level. The influence of the systematic error of the measuring channel on the reliability of the identification of the geometric shape of the local reflectors of the observation object using the results of broadband radar sounding is studied. The created broadband radar measuring
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Dissertations / Theses on the topic "Accuracy problems; Geometric errors"

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Fletcher, Simon. "Computer aided system for intelligent implementation of machine tool error reduction methodologies." Thesis, University of Huddersfield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368312.

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Pokorný, Zdeněk. "Zpracování dat z měření na obráběcích strojích." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382195.

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The Master’s thesis deals with the precision of machine tools, especially with the three-axis vertical milling machine. It is structurally divided into a theoretical and practical part. While the theoretical part focuses on problems of geometric errors and measuring devices, the practical one is devoted to the machine tool being tested. In this case, the data processing and the proposed statistical analysis are essential, and at the end of the thesis another possible way of developing the data processing is outlined.
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Hsu, Yung-Yuan, and 徐永源. "ACCURACY TEST AND GEOMETRIC ERRORS COMPENSATION." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/35181353818611982928.

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博士<br>國立清華大學<br>動力機械工程學系<br>90<br>This paper is devoted to enhance the accuracy of five-axis machine tools. Although five-axis CNC machine tools are widely used in mold and die industry, relevant works in the field of the enhancement of accuracy of five-axis machine tools are sparse. The reason is on one hand the interaction of linear and rotary axes complicates the relationship between the sources of errors and the final errors at the tooltip and makes it difficult to find a suitable compensation method. On the other hand, the increasing kinematical complexity makes it very difficult to measu
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Books on the topic "Accuracy problems; Geometric errors"

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Accurate trisection and other "impossible" subdivisions of angles for practical people: Geometric constructions for the division of arbitrary angles by natural numbers to any required degree of accuracy. [J W Cahill], 2011.

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M, Mulholland Joyce, ed. Drug calculations: Ratio and proportion problems for clinical practice. 9th ed. Elsevier/Mosby, 2012.

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Chuvikov, Dmitriy. Models and algorithms for reconstruction and examination of emergency events of road accidents based on logical artificial intelligence. 2nd ed. INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1220729.

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The purpose of the monograph is to create a methodology, combined expert and simulation models, as well as algorithms and software-modeling tools for reconstruction and examination of accident events for automating decision-making by an expert center employee.&#x0D; The methodology of combining and algorithms of joint work of an expert system based on logical artificial intelligence (mivar approach) and a simulation system for solving problems of reconstruction and examination of road accidents are developed; model reconstruction and examination of the accident in the formalism of the knowledg
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Boudreau, Joseph F., and Eric S. Swanson. Continuum dynamics. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198708636.003.0019.

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The theory and application of a variety of methods to solve partial differential equations are introduced in this chapter. These methods rely on representing continuous quantities with discrete approximations. The resulting finite difference equations are solved using algorithms that stress different traits, such as stability or accuracy. The Crank-Nicolson method is described and extended to multidimensional partial differential equations via the technique of operator splitting. An application to the time-dependent Schrödinger equation, via scattering from a barrier, follows. Methods for solv
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Book chapters on the topic "Accuracy problems; Geometric errors"

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Drouet, P., S. Dubowsky, and C. Mavroidis. "Compensation of Geometric and Elastic Deflection Errors in Large Manipulators Based on Experimental Measurements: Application to a High Accuracy Medical Manipulator." In Advances in Robot Kinematics: Analysis and Control. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-015-9064-8_52.

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Tanwar, Sonam. "A Meshfree-Based Lattice Boltzmann Approach for Simulation of Fluid Flows Within Complex Geometries." In Advances in Computer and Electrical Engineering. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-4760-0.ch006.

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This chapter develops a meshless formulation of lattice Boltzmann method for simulation of fluid flows within complex and irregular geometries. The meshless feature of proposed technique will improve the accuracy of standard lattice Boltzmann method within complicated fluid domains. Discretization of such domains itself may introduce significant numerical errors into the solution. Specifically, in phase transition or moving boundary problems, discretization of the domain is a time-consuming and complex process. In these problems, at each time step, the computational domain may change its shape and need to be re-meshed accordingly for the purpose of accuracy and stability of the solution. The author proposes to combine lattice Boltzmann method with a Galerkin meshfree technique popularly known as element-free Galerkin method in this chapter to remove the difficulties associated with traditional grid-based methods.
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Pathak, Vimal Kumar, and Amit Kumar Singh. "A Particle Swarm Optimization Approach for Minimizing GD&T Error in Additive Manufactured Parts." In Additive Manufacturing. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9624-0.ch008.

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This paper presents a particle swarm optimization (PSO) approach to improve the geometrical accuracy of additive manufacturing (AM) parts by minimizing geometrical dimensioning and tolerancing (GD&amp;T) error. Four AM process parameters viz. Bed temperature, nozzle temperature, Infill, layer thickness are taken as input while circularity and flatness error in ABS part are taken as response. A mathematical model is developed for circularity and flatness error individually using regression technique in terms of process parameters as design variables. For the optimum search of the AM process parameter values, minimization of circularity and flatness are formulated as multi-objective, multi-variable optimization problem which is optimized using particle swarm optimization (PSO) algorithm and hence improving the geometrical accuracy of the ABS part.
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"Non-linear Problems of Machine Accuracy." In Mechanics of Accuracy in Engineering Design of Machines and Robots Volume I: Nominal Functioning and Geometric Accuracy. ASME Press, 2018. http://dx.doi.org/10.1115/1.861615_ch12.

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Sohor, Andrii, and Markiian Sohor. "APPLICATION OF SVD METHOD IN SOLVING INCORRECT GEODESIC PROBLEMS." In Priority areas for development of scientific research: domestic and foreign experience. Publishing House “Baltija Publishing”, 2021. http://dx.doi.org/10.30525/978-9934-26-049-0-36.

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The most reliable method for calculating linear equations of the least squares principle, which can be used to solve incorrect geodetic problems, is based on matrix factorization, which is called a singular expansion. There are other methods that require less machine time and memory. But they are less effective in taking into account the errors of the source information, rounding errors and linear dependence. The methodology of such research is that for any matrix A and any two orthogonal matrices U and V there is a matrix Σ, which is determined from the ratio. The idea of a singular decomposition is that by choosing the right matrices U and V, you can convert most elements of the matrix to zero and make it diagonal with non-negative elements. The novelty and relevance of scientific solutions lies in the feasibility of using a singular decomposition of the matrix to obtain linear equations of the least squares method, which can be used to solve incorrect geodetic problems. The purpose of scientific research is to obtain a stable solution of parametric equations of corrections to the results of measurements in incorrect geodetic problems. Based on the performed research on the application of the singular decomposition method in solving incorrect geodetic problems, we can summarize the following. A singular expansion of a real matrix is any factorization of a matrix with orthogonal columns , an orthogonal matrix and a diagonal matrix , the elements of which are called singular numbers of the matrix , and the columns of matrices and left and right singular vectors. If the matrix has a full rank, then its solution will be unique and stable, which can be obtained by different methods. But the method of singular decomposition, in contrast to other methods, makes it possible to solve problems with incomplete rank. Research shows that the method of solving normal equations by sequential exclusion of unknowns (Gaussian method), which is quite common in geodesy, does not provide stable solutions for poorly conditioned or incorrect geodetic problems. Therefore, in the case of unstable systems of equations, it is proposed to use the method of singular matrix decomposition, which in computational mathematics is called SVD. The SVD singular decomposition method makes it possible to obtain stable solutions of both stable and unstable problems by nature. This possibility to solve incorrect geodetic problems is associated with the application of some limit τ, the choice of which can be made by the relative errors of the matrix of coefficients of parametric equations of corrections and the vector of results of geodetic measurements . Moreover, the solution of the system of normal equations obtained by the SVD method will have the shortest length. Thus, applying the apparatus of the singular decomposition of the matrix of coefficients of parametric equations of corrections to the results of geodetic measurements, we obtained new formulas for estimating the accuracy of the least squares method in solving incorrect geodetic problems. The derived formulas have a compact form and make it possible to easily calculate the elements and estimates of accuracy, almost ignoring the complex procedure of rotation of the matrix of coefficients of normal equations.
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Mishra, Anjana, Bighnaraj Naik, and Suresh Kumar Srichandan. "Missing Value Imputation Using ANN Optimized by Genetic Algorithm." In Research Anthology on Multi-Industry Uses of Genetic Programming and Algorithms. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-8048-6.ch002.

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Missing value arises in almost all serious statistical analyses and creates numerous problems in processing data in databases. In real world applications, information may be missing due to instrumental errors, optional fields and non-response to some questions in surveys, data entry errors, etc. Most of the data mining techniques need analysis of complete data without any missing information and this induces researchers to develop efficient methods to handle them. It is one of the most important areas where research is being carried out for a long time in various domains. The objective of this article is to handle missing data, using an evolutionary (genetic) algorithm including some relatively simple methodologies that can often yield reasonable results. The proposed method uses genetic algorithm and multi-layer perceptron (MLP) for accurately predicting missing data with higher accuracy.
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Kowalski, Marek A., Krzystof A. Sikorski, and Frank Stenger. "Splines." In Selected Topics in Approximation and Computation. Oxford University Press, 1995. http://dx.doi.org/10.1093/oso/9780195080599.003.0005.

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Spline functions are important approximation tools in numerous applications for which high degree polynomial methods perform poorly, such as in computer graphics and geometric modelling, as well as for various engineering problems—especially those involving graphing of numerical solutions and noisy data. Algorithms based on spline functions enjoy minimal approximation errors in wide classes of problems and minimal complexity bounds. In this Chapter we provide a brief introduction to basic classes of polynomial splines, B-Splines, and abstract splines. Further study of spline algorithms as applied to linear problems is outlined in Chapter 7. In this section we define polynomial spline functions, exhibit their interpolatory properties, and construct algorithms to compute them. It turns out that these splines provide interpolating curves that do not exhibit the large oscillations associated with high degree interpolatory polynomials. This is why they find applications in univariate curve matching in computer graphics.
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Charry, Edgar, and Daniel T. H. Lai. "Methods for Improving Foot Displacement Measurements Calculated from Inertial Sensors." In Biomedical Engineering and Information Systems. IGI Global, 2011. http://dx.doi.org/10.4018/978-1-61692-004-3.ch005.

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The use of inertial sensors to measure human movement has recently gained momentum with the advent of low cost micro-electro-mechanical systems (MEMS) technology. These sensors comprise accelerometer and gyroscopes which measure accelerations and angular velocities respectively. Secondary quantities such as displacement can be obtained by integration of these quantities, a method which presents challenging issues due to the problem of accumulative sensor errors. This chapter investigates the spectral evaluation of individual sensor errors and looks at the effectiveness of minimizing these errors using static digital filters. The primary focus is on the derivation of foot displacement data from inertial sensor measurements. The importance of foot, in particular toe displacement measurements is evident in the context of tripping and falling which are serious health concerns for the elderly. The Minimum Toe Clearance (MTC) as an important gait variable for falls-risk prediction and assessment, and therefore the measurement variable of interest. A brief sketch of the current devices employing accelerometers and gyroscopes is presented, highlighting the problems and difficulties reported in literature to achieve good precision. These have been mainly due to the presence of sensor errors and the error accumulative process employed in obtaining displacement measurements. The investigation first proceeds to identify the location of these sensor errors in the frequency domain using the Fast Fourier Transform (FFT) on raw inertial sensor data. The frequency content of velocity and displacement measurements obtained from integrating the inertial data using a well known strap-down method is then explored. These investigations revealed that large sensor errors occurred mainly in the low frequency spectrum while white noise exists in all frequency spectra. The efficacy of employing a band-pass filter to remove a large portion of these errors and their effect on the derived displacements is elaborated on. The cross-correlation of the FFT power spectra from a highly accurate optical measurement system and processed sensor data is used as a metric to evaluate the performance of the band-pass filter at several stages of the processing stage. The motivation is that a more fundamental method would require less computational demand and could lead to more efficient implementations in low-power and systems with limited resources, so that portable sensor based motion measurement system would provide a good degree of measurement accuracy.
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Dodson, Alan, and Terry Moore. "Geodetic Techniques." In Continental Shelf Limits. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195117820.003.0011.

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Establishing a claim to the continental shelf is very much dependent on being able to establish base lines, locations, distances and water depth with a high degree of accuracy. Although this has always been the case, it has become much more significant with the increasing accuracy of measurement instrumentation, the introduction of global (satellite) positioning systems, and the need for international collaboration and agreement. This chapter outlines the measurements or calculations relating to position on the surface of the Earth, the geodetic principles underlying the concepts of coordinates and their reference systems, and the level of accuracy with which positions can be determined. Until the advent of satellite positioning and navigation systems, and in particular the Global Positioning System (GPS), geodetic coordinate systems were of little interest to many of the users of coordinate position information. Indeed, many of today's problems stem from historical misunderstanding of the true complexity of systems of coordinates (Ashkenazi, 1986). The first section of this chapter describes a number of common types of coordinate representation, their implementation in the definition of coordinate systems, and the interpretation of these systems with reference data. Examples of typical local, regional, and geocentric data are outlined as illustration of the general principles. In order to combine coordinates based on differing systems, be it the combination of different national systems or of a national and a geocentric system, it is also necessary to understand the methods of transforming coordinates from one system to another. Details of these methods are presented. Coordinate values within the described systems will usually have been obtained through geodetic observation of national (or international) control networks, with subsequent measurement of detail referenced to those network stations. The chapter therefore gives a brief description of geodetic networks before discussing in some detail the theory of errors and related accuracy analysis which is required in order that realistic accuracy estimates can be ascribed to positional information. The final section presents the definitions and calculation algorithms relating to geodetic distance determination on the Earth's surface, with emphasis on the geodesic— the shortest line between points on an ellipsoidal reference surface, and therefore the line that all distances in article 76 are referred to.
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Mitchell, Alex J. "Why Do Clinicians Have Difficulty Detecting Depression?" In Screening for Depression in Clinical Practice. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780195380194.003.0006.

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Hundreds of studies reveal than most cases of depression remain undetected and untreated. Yet there is growing concern that efforts to increase detection of depression entail unacceptable numbers of persons who are not depressed nonetheless being given a diagnosis and receiving medication. What factors underlie false-positive and false-negative errors? How might clinicians and services address these detection errors? Only about half of primary care practitioners (PCPs) feel confident in diagnosing depression or assessing suicide risk. Yet the issue of underdetection is by no means confined to PCPs or to depression. Convincing data show that clinicians in all medical specialties have difficulty recognizing mental disorders. This includes depression, anxiety, and delirium and dementia. Less discussed in the literature but increasingly recognized as important is the issue of overdetection. In this chapter I will review the predictors of diagnostic errors (false positives and false negatives) with reference to depression in primary care. I will focus on two essential barriers to correct identification: communication and illness complexity. To meaningfully discuss errors in recognition, it is important to first establish baseline rates of depression. Prevalence exerts a powerful influence upon detection accuracy, not least because clinicians usually have a higher index of suspicion for high-risk patients. The World Health Organization (WHO) study on Psychological Problems in General Health Care (PPGHC), conducted across 14 countries, found that 26% of individuals visiting their PCP had at least one psychiatric disorder as defined by ICD-10 criteria. Fourteen percent had major depression. Almost identical rates were reported from the European Study of the Epidemiology of Mental Disorders (ESEMeD). If one examines depression in older people, the point prevalence of major depression is lower in rural than urban primary care practices (8.3% versus 14.8%). Further, if one combines a 14% rate of major depression with 10% who have minor depression, then the combined rate approaches 25%. Approximately 100 studies concerning the unassisted recognition rate of depression in primary care have been published, but only a third have used a robust semi-structured interview as a gold standard.
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Conference papers on the topic "Accuracy problems; Geometric errors"

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Fukuoka, Toshimichi, and Keisuke Nakano. "Improvement of Tightening Accuracy of Torque Control Method by Taking Account Geometric Errors in Threaded Fasteners." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63083.

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Torque control method is commonly used when tightening bolted joints because of its easy operation. However, the method involves an essential problem of fairly large scatter in bolt preloads. It has been reported that even if the same torque is applied, bolt preloads show a considerable scatter, e.g., ranging from 25% to 35%. A scatter in coefficients of friction on nut bearing surface and thread pressure flank is a primary source of bolt preload scatter. Meanwhile, the effect of Equivalent Friction Diameter at the bearing surfaces of nut and bolt head cannot be ignored. The scatter in Equival
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Ouafi, Abderrazak El, Michel Guillot, and Abdellah Bedrouni. "Improving the Accuracy of Multi-Axis Machines Through On-Line Error Compensation Using Neural Networks." In ASME 1998 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/detc98/dac-5641.

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Abstract This research is devoted to one of the most fundamental problems in precision engineering: multi-axis machines accuracy. The paper presents a new approach designed to support the implementation of software error compensation of geometric, thermal and dynamic errors for enhancing the accuracy of multi-axis machines. The accuracy of multi-axis machines can be significantly improved using an intelligent integration of sensor information to perform the compensation function. The compensation process consists of the following major steps carried out on-line: continuous monitoring of the ma
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Chen, Zezhong C., and Wei Cai. "A Generic, Geometric Approach to Accurate Machining-Error Predictions for 3-Axis CNC Milling of Sculptured Surface Parts: Part II — Applications and Analysis." In ASME 2006 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/detc2006-99367.

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As sculptured surfaces are widely used in mechanical design, machining sculptured surface parts accurately is highly demanded in industry; however, it is quite challenging to meet their demand. Due to the geometric complexity of these surfaces, the tool-surface geometric mismatch always causes machining errors when the tool cuts along the tool paths. To prevent surface gouging, where the machining error is greater than the part tolerance, state-of-the-art CAM software usually determines cutter contact (CC) points on the tool paths first, and then simulates the machining to check the errors cau
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Fong, Jeffrey T., Pedro V. Marcal, Robert Rainsberger, Li Ma, N. Alan Heckert, and James J. Filliben. "Finite Element Method Solution Uncertainty, Asymptotic Solution, and a New Approach to Accuracy Assessment." In ASME 2018 Verification and Validation Symposium. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/vvs2018-9320.

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Errors and uncertainties in finite element method (FEM) computing can come from the following eight sources, the first four being FEM-method-specific, and the second four, model-specific: (1) Computing platform such as ABAQUS, ANSYS, COMSOL, LS-DYNA, etc.; (2) choice of element types in designing a mesh; (3) choice of mean element density or degrees of freedom (d.o.f.) in the same mesh design; (4) choice of a percent relative error (PRE) or the Rate of PRE per d.o.f. on a log-log plot to assure solution convergence; (5) uncertainty in geometric parameters of the model; (6) uncertainty in physi
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Rainsberger, Robert B., Jeffrey T. Fong, and Pedro V. Marcal. "A Super-Parametric Approach to Estimating Accuracy and Uncertainty of the Finite Element Method (*)." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63890.

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A finite element method (FEM)-based solution of an industry-grade problem with complex geometry, partially-validated material property databases, incomplete knowledge of prior loading histories, and an increasingly user-friendly human-computer interface, is extremely difficult to verify because of at least five major sources of errors or solution uncertainty (SU), namely, (SU-1) numerical algorithm of approximation for solving a system of partial differential equations with initial and boundary conditions; (SU-2) the choice of the element type in the design of a finite element mesh; (SU-3) the
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Khan, Maqsood A., and Zezhong C. Chen. "An Effective Approach to Approximating 2-D Free-Form Curve Offsets for B-Spline NC Tool Paths With Offset Error Globally Bounded." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-29150.

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The topic of representing the offset of a 2-D B-spline curve in the same form has been under research for a long time, and it has many industrial applications, especially, in NC tool path generation for pocketing. For B-spline tool paths, it is often required that the tool paths have fewer control points, lower base function degree, and higher geometric accuracy. However, the existing methods often generate the offsets of 2-D free-form curves in the form of B-spline curves with high function degree and many control points. Although these offsets are useful in computer-aided design, they are in
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7

Chew, M., and M. Phan. "Application of Learning Control Theory to Mechanisms: Part 1 — Inverse Kinematics and Parametric Error Compensation." In ASME 1994 Design Technical Conferences collocated with the ASME 1994 International Computers in Engineering Conference and Exhibition and the ASME 1994 8th Annual Database Symposium. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/detc1994-0239.

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Abstract Fundamental concepts of learning control theory are applied to problems in mechanisms. The theory provides an integrated approach that can simplify the numerical solution of inverse kinematics of mechanisms as well as the practical problem of inverse kinematics in the presence of parametric errors. The procedure makes repeated use of forward kinematics that can be carried out analytically for off-line computation, or experimentally for on-line tuning of mechanisms, to arrive at the correct inverse kinematic solution. With repetitive learning, learning control theory will identify the
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Jbira, Ibtissem, Antoine Tahan, Mohamed Ali Mahjoub, and Borhen Louhichi. "Evaluation of the Algorithmic Error of New Specification Tools for an ISO 14405-1:2016 Size." In ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-85669.

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Due to machine tool imprecisions during manufacturing, the actual product cannot be the same as the nominal model. The product’s geometric variations influence the geometrical requirements of functionality and assembly [6, 8]; this remains a problem of industrial performance and plays a major role in the quality and cost of products; hence the need for a reliable strategy to evaluate errors in the final inspection of part quality. Among all the geometric characteristics, the circular characteristic is very common on most parts. Therefore, the measurement and evaluation of circularity with a hi
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Bohan, Zhao, Gao Feng, Li Yan, Zhang Dongya, Zhang Wanli, and Zhou Fei. "Study on Generation and Optimization Methodology of On-Machine Measurement Schemes for Multi-Axis CNC Machine Tool." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71263.

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Quality Control (QC) is one of the most important phases in the production process. In tradition, the workpiece must be inspected for dimension and shape errors in the QC lab or Coordinate Measuring Machine (CMM) after being machined, which is time-consuming and labor-intensive, especially for large scale parts. Thus the only practical way to do that is to migrate the critical primary inspection operations upstream from the QC lab or CMM to the production floor, and that’s what On-Machine Measurement (OMM) does. OMM technology can inspect the workpiece on its operating station by motion contro
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Durali, Mohammad, Ali Nabi, and Amir Fazeli. "Design and Simulation of an Off-Line Internal Navigation System for Pipeline Inspection Applications." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-43641.

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The aim of this paper is to design an inertial navigation system (INS) for use in a geometry pipe inspection gauge, capable of measuring pipeline movements and producing the line’s 3D map with a reasonable accuracy. A suitable reference path was generated as a design platform. Solving the navigation equations and compensating for the errors, by using extended Kalman filter (EKF) approach, the INS path was generated and its position errors in all three directions were considered. Divergence problems due to far apart GPS position observations, was overcome by defining suitable threshold for the
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