Rounding Research Articles

Single sensor three point on-line measurement method of precision rolling bearings

With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument.

Influence of shape errors and inertia effects on the error motion of the aerostatic spindle

In this study, an extended Reynolds equation incorporating the shape errors and the inertia effects of compressible fluid was formulated. The pressure-solving equation for the gas film was constructed using a second-order finite difference method. By combining the measurement data from the cylindricity of multiple shafts obtained from a cylindricity measuring instrument, the variation of the aerostatic bearing load capacity with the rotation of the shaft was calculated, both with and without considering the inertia effect. An experimental rig was also constructed to measure the error motion data of the corresponding shaft. The results of numerical analysis and experimental validation demonstrated that shafts with larger cylindricity error values exhibit greater deviations in the calculated bearing load capacity, which correspondingly leads to larger radial error motion values measured in the experiment. When the roundness error value of the shaft is small or the shaft speed is low, the influence of inertial effects on the calculation results of the load capacity deviation is minimal and can generally be disregarded.

Before reflexivity comes preflexivity

Before reflexivity comes preflexivity

Risk-benefit assessment of foods – status, challenges, and opportunities

Abstract Evaluation of tradeoffs between toxicological and microbiological risks and nutritional risks and benefits associated with food consumption is a relatively new research field. Several initiatives have been taken to develop and harmonize approaches to assess health risks and benefits of foods in an integrated assessment - risk-benefit assessment. Today, the pool of published risk-benefit assessments of foods is still very heterogeneous with respect to e.g. evaluation of weight of evidence, methodology and degree of quantification and integration of risk and benefits. It is a research area in continuous development and has the potential to support decision making in food safety and nutrition. This presentation will set the scene for the workshop by introducing the concepts of RBA of foods and provide an overview of different methods to make such assessments based on examples of previous studies and ongoing research within the field. Emphasis will be put on the various measures of health risk-benefit balance, ranging from qualitative to quantitative approaches, and their individual strengths and weaknesses. The presentation will round off with a discussion of current challenges in RBA and highlight opportunities for further developments in the field.

Алгоритмы дискретной фильтрации на основе модифицированной взвешенной ортогонализации Грама –Шмидта для дискретных стохастических систем с мультипликативными и аддитивными шумами

Discrete-time stochastic systems with multiplicative and additive noises describe a wide class of mathematical models of complex systems, for example, industrial-technological, energy, economic, telecommunication, aerospace systems, etc. An important class of algorithms for processing measure ment information in complex systems are Kalman-type discrete-time filtering algorithms. Purpose. Construction of new discrete-time filtering algorithms for discrete-time linear systems with multiplicative and additive noises based on numerically stable modified weighted Gram – Schmidt orthogonalization (MWGS). Methodology. The methods of computational linear algebra were used, namely, the direct procedu re of MWGS-orthogonalization, the theory of Kalman filtering, methods of scientific programming in MATLAB. Findings. New LD-algorithms for discrete-time filtering in covariance and informational form for discrete-time stochastic systems with multiplicative and additive noises are constructed. The algorithms have an extended array form allowing updates for all necessary filter values. The method employs numerically stable modified weighted Gram – Schmidt orthogonalization. Algebraic equiva lence of LD-filters to Kalman-type covariance and informational algorithms for linear discrete time stochastic systems with multiplicative and additive noises is proved. The conducted numerical experiments have shown the effectiveness of the proposed algorithms using the example of solving the problem of parametric estimation of a model of almost rectilinear motion, as well as their savings in computation time compared to previously constructed UD filters. Value. New discrete-time filtering LD-algorithms can be used as a reliable computational alterna tive to the Kalman-type “standard algorithms” since they have the property being numerically stable to machine round-off errors due to the use of the MWGS orthogonalization computational procedure at each iteration of the algorithm. The results can be used to solve problems of measurement information processing in discrete-time systems with multiplicative and additive noise.

Analysis of temperature-dependent thermal conductivity and fin efficiency: Direct Akbari-Ganji method

The vast majority of engineering issues, particularly heat transport equations, have a non-linear form. The analytical solution of temperature distribution, fin effectiveness, and fin efficiency of straight convective fins that transport heat with temperature-dependent thermal conductivity convection is derived in this work using the Direct Akbari-Ganji method (DAGM). DAGM is an effective methodology that is very simple and takes less time to solve non-linear temperature distribution fin problems. In the present investigation, Direct Akbari-Ganji technique offers desirable solutions to heat transfer problems. The round-off error is smaller compared to other methods. For the purpose of calibrating the error accuracy of the suggested direct technique, this result is compared with the numerical and earlier solution. The outcomes show that the DAGM for heat transfer equations in engineering situations has excellent validity and considerable promise. Finally, it is clear that when the thermo-geometric fin parameter increases, so does the fin efficiency. The homogeneity of the fin is due to the variable thermal conductivity. Four convection conditions with constant coefficients, growing and decaying convection coefficient with fin temperature are discussed.

An extended stress-based forming limit diagram focusing on the wrinkling phenomenon and the effect of the normal pressure on clamped surfaces

A novel wrinkling limit representation following the pattern of the conventional forming limit curves (FLCs) and the stress-based forming limit curves (SFLCs) as well as the application of the assumed criterion in finite element modelling are discussed in this manuscript. FLCs can partially refer to the wrinkling potential in the area left to the uniaxial tension line, but just like the SFLCs, cannot characterize the limits of the material behavior in a deeper sense, if negative in-plane stress and normal pressure act together on the sheet. This study predicts the wrinkling risk of clamped surfaces with a stress-based criterion through solving the analytical equations of the critical compressive stress causing wrinkling, and the corresponding blank holder pressure. The critical values were calculated based on the Wang and Cao’s theory using Hill48 anisotropic yield function coupled with the Swift hardening law. The results draw a novel wrinkling limit curve representation methodology, in which the minor stress responsible for wrinkling and its ratio to the major stress are distinguished in the function of the applied blank holder pressure. The applicability of the calculated curves was investigated using finite element simulations, which showed that this method provides the opportunity to quantitatively interpret how close a component is to the wrinkling limit. The calculated wrinkling tendencies were verified by standard cup drawing tests supplemented by round shape error measurements on three different automotive steel sheets. It can be stated that the obtained numerical conditions of wrinkling were fitted to the experiments fairly well.

Implementing circularity measurements in industry 4.0-based manufacturing metrology using MQTT protocol and Open CV: A case study.

In the context of Industry 4.0, manufacturing metrology is crucial for inspecting and measuring machines. The Internet of Things (IoT) technology enables seamless communication between advanced industrial devices through local and cloud computing servers. This study investigates the use of the MQTT protocol to enhance the performance of circularity measurement data transmission between cloud servers and round-hole data sources through Open CV. Accurate inspection of circular characteristics, particularly roundness errors, is vital for lubricant distribution, assemblies, and rotational force innovation. Circularity measurement techniques employ algorithms like the minimal zone circle tolerance algorithm. Vision inspection systems, utilizing image processing techniques, can promptly and accurately detect quality concerns by analyzing the model's surface through circular dimension analysis. This involves sending the model's image to a computer, which employs techniques such as Hough Transform, Edge Detection, and Contour Analysis to identify circular features and extract relevant parameters. This method is utilized in the camera industry and component assembly. To assess the performance, a comparative experiment was conducted between the non-contact-based 3SMVI system and the contact-based CMM system widely used in various industries for roundness evaluation. The CMM technique is known for its high precision but is time-consuming. Experimental results indicated a variation of 5 to 9.6 micrometers between the two methods. It is suggested that using a high-resolution camera and appropriate lighting conditions can further enhance result precision.

Influence of Inner Roller Geometric Parameters on Counter-Roller Spinning with 6061 Aluminum Alloy Tube

The inner roller exerts a supportive and thinning effect on the inner side of the tube during counter-roller spinning. In this paper, the Finite Element Analysis (FEA) model of counter-roller spinning for a 6061 aluminum alloy tube was established based on the ABAQUS/Explicit module. The deformation characteristics and the influence of inner roller geometrical parameters on the tube spinning were analyzed. The results showed that the stress–strain on the outer of the tube was greater than that of the inner, and flaring was more prone to occur in the initial stage of counter-roller spinning compared to traditional mandrel spinning. The order of the effects of geometrical parameters of the inner roller on the roundness error and wall thickness deviation was as follows: nose radius > diameter > front angle. The order of factors influencing the inner and outer spinning force was as follows: diameter > nose radius > front angle. Increasing the diameter of the inner roller can improve the spinning stability and forming accuracy of counter-roller spinning. It was beneficial to improve the forming accuracy when the nose radius of the inner roller was slightly larger than that of the outer roller. The front angle of the inner roller has little influence on the spinning forming accuracy.

100 år med Danmarks Stednavne

Names are an important part of the intangible cultural heritage that our language represents and placenames are an important source for many subjects such as language research, geography, history, archaeology etc. Therefore, it is an important task to provide knowledge about place-names in a form that can be used widely. This knowledge can be found in the book series Danmarks Stednavne (‘Place-Names of Denmark’), and in 2022, it is one hundred years since the first volume of the series was published. In this article, we present the editorial history of the series and describe the process in the development of the volumes, each standing on the shoulders of its predecessors. The series’ chosen form of production based on a land-registration system, which today can be considered obsolete, is explained, along with the variation regarding which classes of place-names have been treated in each volume and the varying inclusion of settlement-historical presentations based on the place-name evidence. While such issues have changed, the series has upheld a consistent focus on listing historical forms of the place-names and interpreting their etymology. The presentation of the publishing process and changed editorial principles in the course of time are rounded off with the current editorial plans for the future of Danmarks Stednavne.

Stochastic Rounding Variance and Probabilistic Bounds: A New Approach

Stochastic Rounding Variance and Probabilistic Bounds: A New Approach

From Reading Nonsensical Jabberwocky to Proposing Topics for English Pedagogy

Portrayed as a monster and villain, narrated in seven stanzas in an iambic tetrameter metrics, Jabberwocky is a phenomenal poem. This poem, loaded with “esoteric” and nonce words, was mostly researched in the realms of translation and psycholinguistics, leading to a dearth of studies in L2 pedagogy. The posed question was “What are some latent themes or topics for ELT material development that can be revealed from the discernibly nonsensical language of Lewis Carroll’s Jabberwocky poem?” Descriptive phenomenological design suited this study’s purpose to delineate emic language pedagogical aspects of this poem. Thematic analysis was employed by performing a 6-step framework. This current study has yielded three main themes that propose Jabberwocky poem as an alternative source of English material development. The latent themes circumnavigate around morphology, syntax, and phonology. Morphologically, L2 learners could delve further to the two-word-formation processes, namely: portmanteau and coinage. Syntactically, Jabberwocky poem can hone the skill in detecting parts of speech. Phonologically, the concept of phonaesthesia fosters sound interpretation. This study rounds off by thanking Lewis Carroll for sharp-wittedly writing Jabberwocky poem and proposing an alternative to material developers as well as English teachers and practitioners to incorporate this work of art into their instructions.

HDLBC: A lightweight block cipher with high diffusion

Both the diffusion property and the area consumption are two important evaluation criteria in the design and implementation of symmetric encryption algorithms. Many AND-Rotation-XOR (AND-RX) block ciphers are usually designed by reducing the diffusion property to minimize the area consumption. On the other hand, these AND-RX block ciphers use multiple round function operations to achieve the enough diffusion property, which always induce more area consumption in their hardware implementation. How to trade off the diffusion property and the area consumption appears to be an interesting task in the design of block cipher. In this paper, HDLBC as a new family of lightweight block cipher (with 64-bit plaintext and 64-bit/128-bit key) for the Internet of Things (IoT) is proposed. More specifically, the HDLBC is designed by using only two F-functions (RA1 and RA2), where the non-linear layer of the F-functions is constructed by the NAND operation that consumes the least area among the non-linear logic operations. To the best of our knowledge, HDLBC cipher requires the minimum number of F-functions to provide the diffusion property, where the F-functions require fewer implementation resources than the F-functions of existing similar encryption algorithms. It illustrates the hardware implementation of HDLBC cipher on SMIC 0.18μm requires only 1248 Gate Equivalents (GEs), its throughput rate is 256 Kbps at 100 KHz. Compared with other encryption algorithms, the implementation performance of HDLBC cipher achieves well-balanced in both the area consumption and diffusion property. Moreover, the security analysis shows that HDLBC cipher has enough security margin against various known attacks, such as differential cryptanalysis, linear cryptanalysis, impossible differential cryptanalysis, zero correlation cryptanalysis, etc.

Digital Cognitive Behavioral- and Mindfulness-Based Stress-Management Interventions for Survivors of Breast Cancer: Development Study.

Psychosocial stress-management interventions can reduce stress and distress and improve the quality of life for survivors of cancer. As these in-person interventions are not always offered or accessible, evidence-informed digital stress-management interventions may have the potential to improve outreach of psychosocial support for survivors of cancer. Few such digital interventions exist so far, few if any have been developed specifically for survivors of breast cancer, and few if any have attempted to explore more than 1 distinct type of intervention framework. This study aimed to develop 2 digital psychosocial stress-management interventions for survivors of breast cancer; 1 cognitive behavioral therapy-based intervention (CBI), and 1 mindfulness-based intervention (MBI). The development of the CBI and MBI interventions originated from the existing StressProffen program, a digital stress-management intervention program for survivors of cancer, based on a primarily cognitive behavioral therapeutic concept. Development processes entailed a multidisciplinary design approach and were iteratively conducted in close collaboration between key stakeholders, including experts within psychosocial oncology, cancer epidemiology, stress-management, and eHealth as well as survivors of breast cancer and health care providers. Core psychosocial oncology stress-management and cancer epidemiology experts first conducted a series of workshops to identify cognitive behavioral and mindfulness specific StressProffen content, overlapping psychoeducational content, and areas where development and incorporation of new material were needed. Following the program content adaptation and development phase, phases related to user testing of new content and technical, privacy, security, and ethical aspects and adjustments ensued. Intervention content for the distinct CBI and MBI interventions was refined in iterative user-centered design processes and adjusted to electronic format through stakeholder-centered iterations. For the CBI version, the mindfulness-based content of the original StressProffen was removed, and for the MBI version, cognitive behavioral content was removed. Varying degrees of new content were created for both versions, using a similar layout as for the original StressProffen program. New content and new exercises in particular were tested by survivors of breast cancer and a project-related editorial team, resulting in subsequent user centered adjustments, including ensuring auditory versions and adequate explanations before less intuitive sections. Other improvements included implementing a standard closing sentence to round off every exercise, and allowing participants to choose the length of some of the mindfulness exercises. A legal disclaimer and a description of data collection, user rights and study contact information were included to meet ethical, privacy, and security requirements. This study shows how theory specific (ie, CBI and MBI) digital stress-management interventions for survivors of breast cancer can be developed through extensive collaborations between key stakeholders, including scientists, health care providers, and survivors of breast cancer. Offering a variety of evidence-informed stress-management approaches may potentially increase interest for outreach and impact of psychosocial interventions for survivors of cancer. RR2-10.2196/47195.

Cryptanalysis Of A Type Of White-Box Implementations Of The SM4 Block Cipher

Abstract The SM4 block cipher is a Chinese national standard and an ISO international standard. Since white-box cryptography has many real-life applications nowadays, a few white-box implementations of SM4 has been proposed, among which a type of constructions is dominated, which uses a linear or affine diagonal block encoding to protect the original three 32-bit branches entering a round function and uses its inverse as the input encoding to the S-box layer. In this paper, we analyse the security of this type of constructions against Lepoint et al.’s collision-based attack method. Our experiment under a small fraction of (encodings, round key) combinations shows that the rank of the concerned linear system is much less than the number of the involved unknowns, meaning these white-box SM4 implementations should resist Lepoint et al.’s method, but we leave it as an open problem whether there are such encodings that the rank of the corresponding linear system is slightly less than the number of the involved unknowns, in which scenario Lepoint et al.’s method may be used to recover a round key for the case with linear encodings and to remove most white-box operations until mainly some Boolean masks for the case with affine encodings.

On Boomerang Attacks on Quadratic Feistel Ciphers

The recent introduction of the Boomerang Connectivity Table (BCT) at Eurocrypt 2018 revived interest in boomerang cryptanalysis and in the need to correctly build boomerang distinguishers. Several important advances have been made on this matter, with in particular the study of the extension of the BCT theory to multiple rounds and to different types of ciphers.In this paper, we pursue these investigations by studying the specific case of quadratic Feistel ciphers, motivated by the need to look at two particularly lightweight ciphers, KATAN and Simon. Our analysis shows that their light round function leads to an extreme case, as a one-round boomerang can only have a probability of 0 or 1. We identify six papers presenting boomerang analyses of KATAN or Simon and all use the naive approach to compute the distinguisher’s probability. We are able to prove that several results are theoretically incorrect and we run experiments to check the probability of the others. Many do not have the claimed probability: it fails distinguishing in some cases, but we also identify instances where the experimental probability turns out to be better than the claimed one.To address this shortfall, we propose an SMT model taking into account the boomerang constraints. We present several experimentally-verified related-key distinguishers obtained with our new technique: on KATAN32 a 151-round boomerang and on Simon-32/64 a 17-round boomerang, a 19-round rotational-xor boomerang and a 15-round rotational-xor-differential boomerang.Furthermore, we extend our 19-round distinguisher into a 25-round rotational-xor rectangle attack on Simon-32/64. To the best of our knowledge this attack reaches one more round than previously published results.

Numerical integration of the Cauchy problem with non-singular special points

Solutions of many applied Cauchy problems for ordinary differential equations have one or more multiple zeros on the integration segment. Examples are the equations of special functions of mathematical physics. The presence of multiples of zeros significantly complicates the numerical calculation, since such problems are ill-conditioned. Round-off errors may corrupt all decimal digits of the solution. Therefore, multiple zeros should be treated as special points of the differential equations. In the present paper, a local solution transformation is proposed, which converts the multiple zero into a simple one. The calculation of the latter is not difficult. This makes it possible to dramatically improve the accuracy and reliability of the calculation. Illustrative examples have been carried out, which confirm the advantages of the proposed method.

Punctuated chaos and the unpredictability of the Galactic Centre S-star orbital evolution

ABSTRACT We investigate the chaotic behaviour of the S-star cluster in the Galactic Centre using precise N-body calculations, free from round-off or discretization errors. Our findings reveal that chaos among the Galactic Centre S-stars arises from close encounters, particularly among pairs and near the massive central body. These encounters induce perturbations, causing sudden changes in the orbital energies of the interacting stars. Consequently, neighbouring solutions experience roughly exponential growth in separation. We propose a theory of ‘punctuated chaos’ that describes the S-star cluster’s chaotic behaviour. This phenomenon results from nearly linear growth in the separation between neighbouring orbits after repeated finite perturbations. Each participating star’s orbit experiences discrete, abrupt changes in energy due to the perturbations. The cumulative effect of these events is further amplified by the steady drift in orbital phase. In the Galactic Centre, perturbations originate from coincidental encounters occurring within a distance of ≲100 au between at least two stars (in some cases, three stars). Our model satisfactorily explains the observed exponential growth in the 27 S-stars cluster. We determine that the S-star system has a Lyapunov time-scale of approximately 462 ± 74 yr. For the coming millennium, chaos in the S-star cluster will be driven mainly by a few of the closest orbiting stars: S2, S5, S6, S8, S9, S14, S18, S31, S21, S24, S27, S29, and S38.

Exact Matrix Factorization Updates for Nonlinear Programming

LU and Cholesky matrix factorization algorithms are core subroutines used to solve systems of linear equations (SLEs) encountered when solving an optimization problem. Standard floating-point algorithms are highly efficient but remain susceptible to the accumulation of round-off errors, which can lead solvers to return feasibility and optimality claims that are actually invalid. This paper introduces a novel direct solution approach for solving sequences of closely related SLEs encountered in nonlinear programming efficiently and without round-off errors. Specifically, it introduces rank-one update algorithms for the round-off error–free factorization framework, a tool set built on integer-preserving arithmetic that has led to the development and implementation of extremely reliable subroutines for solving SLEs occurring in linear programming. The formal guarantees of the presented algorithms are established through the derivation of theoretical insights. Their advantages are supported with computational experiments, which demonstrate upward of 75× improvements over exact factorization runtimes on fully dense matrices with more than one million entries. A significant advantage of the featured integer-preserving framework is that the length of any matrix coefficient produced by its algorithms is bounded polynomially in the size of the inputs without having to resort to greatest common divisor operations, which are required by and thereby hinder an efficient implementation of exact rational arithmetic approaches. History: Accepted by Antonio Frangioni, Area Editor for Design & Analysis of Algorithms–Continuous. Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information ( https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2021.0331 ) as well as from the IJOC GitHub software repository ( https://github.com/INFORMSJoC/2021.0331 ). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/ .

Walter Rounds off Its Range of Solid Carbide Universal Milling Cutters

Walter Rounds off Its Range of Solid Carbide Universal Milling Cutters