Regular Version Research Articles

A shape optimization algorithm based on directional derivatives for three‐dimensional contact problems

AbstractThis work deals with shape optimization for contact mechanics. More specifically, the linear elasticity model is considered under the small deformations hypothesis, and the elastic body is assumed to be in contact (sliding or with Tresca friction) with a rigid foundation. The mathematical formulations studied are two regularized versions of the original variational inequality: the penalty formulation and the augmented Lagrangian formulation. In order to get the shape derivatives associated to those two non‐differentiable formulations, we follow an approach based on directional derivatives introduced in previous works. This allows us to develop a gradient‐based topology optimization algorithm, built on these derivatives and a level‐set representation of shapes. The algorithm also benefits from a mesh‐cutting technique, which gives an explicit representation of the shape at each iteration, and enables us to apply the boundary conditions strongly on the contact zone. The different steps of the method are detailed. Then, to validate the approach, some numerical results on two‐dimensional and three‐dimensional benchmarks are presented.

A regular version of the extremal RN spacetime

A modified extremal Reissner-Nordstrom geometry, void of singularities, is proposed in this work, by means of an exponential factor depending on a positive constant k. All the metric coefficients are positive and finite and the spacetime has no any horizon. The curvature invariants are regular at the origin of coordinates and at infinity. The energy conditions for the stress tensor associate to the imperfect fluid are investigated. The gravitational field presents repulsive properties near the gravitational radius associated to the mass m. With the choice k=1/m, the Komar energy WK of the mass m changes its sign at r=λ (λ is the Compton wavelength of m), when the classical energy mc2 equals the energy ħc/r.

Constructing various paraxial beams out of regular and modified Bessel-Gaussian modes

Various superpositions of Bessel-Gaussian beams and modified Bessel-Gaussian beams are considered. Two selected parameters characterizing these beams, with respect to which the superpositions are constructed, are the topological index $n$ associated with the orbital angular momentum carried by the beam and $\ensuremath{\chi}$ related to the dilation of the beam. It is shown that, from these modes, by choosing appropriate weighting factors, it is possible to create a number of well- and less-known solutions of the paraxial equation: a Gaussian (shifted and nonshifted) beam, a $\ensuremath{\gamma}$ beam, Kummer-Gaussian beam, a special hyperbolic Bessel-Gaussian beam, a certain special Laguerre-Gaussian beam, and generalized paraxial beams in hyperbolic and regular versions.

Regularity of interval fuzzy matrices

Max-min (fuzzy) algebra is applied to various problems related to optimization, modeling of discrete dynamic systems, cluster analysis and is used for designing some graph-theoretical algorithms, also for the computations of the optimization problems such as scheduling in which the objective function depends on the matrix operations maximum and minimum.The columns of a matrix A are strongly independent if the max-min (fuzzy) linear system A⊗x=b has a unique solution for at least one vector b. A square matrix A with strongly linearly independent columns is called strongly regular. The investigation of properties of strongly regular interval matrices is important for the applications.The paper deals with the analysis of three versions of the strong regularity of interval matrices, i.e., universal strong regularity, possibly strong regularity and EA/AE strong regularity. For each concept of strong regularity we will present equivalent conditions and polynomial algorithms for their checking.

Impact of e-cigarettes as cancer risk: A protocol for systematic review and meta-analysis

The use of electronic cigarettes is one of the current public health problems on increasing alert, has been growing at an accelerating rate, and has become a public health emergency. Its importance is explained by the continuous growth and acceleration of oncological rates among all ages versus the absence of high-quality evidence, correlated to the use of nicotine derived products, being at their regular versions or the new ones. Available preclinical data indicate that activation of the sympathetic nervous system by nicotine inhaled from e-cigarettes may stimulate cancer development and growth by several mechanisms, which results can significantly reduce life's quality. This systematic review and meta-analysis protocol aims to clarify the connection between the use of electronic cigarettes by adults over the age of 18 and the development of malignant neoplastic diseases. The proposed systematic review and meta-analysis will be reported conforming to the preferred reporting items for systematic reviews and meta-analyses guidelines. Will include the following studies: case-control or cohort studies showing adults (18 years old age) using e-cigarettes. There will be no language or publication period restrictions. Articles published, but not peer-reviewed, will not be included in the review. Data will be entered in the Review Manager software (RevMan5.2.3). For dichotomous outcomes, we extracted or calculated the OR and 95% CI for each study. In case of heterogeneity (I²>50%), the random-effects model will be used to combine the studies to calculate the OR and 95% CI.

Modeling the properties of multilayer heat-reflecting screens taking into account the uncertainty of structural parameters

The article is devoted to the study of parametric properties of multilayer heat-reflecting screens. Special attention is paid to the parameters of shielding and heat flow absorption. The study, its numerical and analytical techniques ensure that the fuzzy input situation is taken into account. The fuzziness is generated by the variance of both the values of geometric parameters and the actual values of structural elements. The proposed analytical and numerical research techniques are applicable in a wide range of productions of thermal protective products – for the energy industry, radio electronics, aerospace instrumentation, production of building structural elements. The theory of fuzzy sets is actively applied in terms of the heuristic principle of expansion. It is the basis for regular versions of the presented models. The underlying calculations are based on fuzzy numbers that represent exogenous parameters.

The Influence of COVID-19 on University Students' Well-Being, Physical Activity, Body Composition, and Strength Endurance.

Very few scientific studies have simultaneously evaluated changes in well-being (WB), physical activity (PA), and strength endurance (SE) based on results from before and during the COVID-19 pandemic. The aim of the study was to assess WB, PA, and SE levels, as well as body composition parameters in university students before and during the pandemic. The study included 30 males and 30 females (mean age: 21.7 ± 2.51 and 21.6 ± 2.34 years, respectively). Well-being using the Self-Perception Questionnaire (POMS), PA from the Polish regular version of the International Physical Activity Questionnaire (IPAQ), body composition parameters using the InBody 270 analyzer, and SE based on the results of a 12 min test involving a Concept 2PM-5 rowing ergometer were assessed before and during the pandemic. An assessment of university students' WB revealed a significant increase in variables such as tension, depression, anger, confusion, and a significant decline in vigor (p < 0.05). In both sexes, PA and SE decreased significantly-from 2115.4 to 1822.8 METs-min/week and from 2184.5 to 2035 m, respectively, in males, and from 1793.5 to 1699.8 METs-min/week and from 2021.5 to 1943.8 m, respectively, in females. At the same time, body mass and BMI values increased significantly (p < 0.001) in both females and males. The COVID-19 pandemic caused a significant decrease in WB, PA and SE levels in young females and males, and led to a significant increase in their body mass and BMI.

Clustering has a meaning: optimization of angular similarity to detect 3D geometric anomalies in geological terrains

Abstract. The geological potential of sparse subsurface data is not being fully exploited since the available workflows are not specifically designed to detect and interpret 3D geometric anomalies hidden in the data. We develop a new unsupervised machine learning framework to cluster and analyze the spatial distribution of orientations sampled throughout a geological interface. Our method employs Delaunay triangulation and clustering with the squared Euclidean distance to cluster local unit orientations, which results in minimization of the within-cluster cosine distance. We performed the clustering on two representations of the triangles: normal and dip vectors. The classes resulting from clustering were attached to a geometric center of a triangle (irregular version). We also developed a regular version of spatial clustering which allows the question to be answered as to whether points from a grid structure can be affected by anomalies. To illustrate the usefulness of the combination between cosine distance as a dissimilarity metric and two cartographic versions, we analyzed subsurface data documenting two horizons: (1) the bottom Jurassic surface from the Central European Basin System (CEBS) and (2) an interface between Middle Jurassic units within the Kraków–Silesian Homocline (KSH), which is a part of the CEBS. The empirical results suggest that clustering normal vectors may result in near-collinear cluster centers and boundaries between clusters of similar trend, thus pointing to axis of a potential megacylinder. Clustering dip vectors, on the other hand, resulted in near-co-circular cluster centers, thus pointing to a potential megacone. We also show that the linear arrangements of the anomalies and their topological relationships and internal structure can provide insights regarding the internal structure of the singularity, e.g., whether it may be due to drilling a nonvertical fault plane or due to a wider deformation zone composed of many smaller faults.

Paths to Healthier Eating: Perceptions and Interventions for Success

Paths to Healthier Eating: Perceptions and Interventions for Success

Light or Regular, Now or Later: The Impact of Advance Ordering and Restrained Eating on Choices and Consumption of Light and Regular Vice Food

Research has shown that an effective way of encouraging consumers to make healthier food choices is to have them choose early (i.e., advance ordering). However, the effectiveness of advance ordering remains unknown when consumers choose between regular and light versions of unhealthy food (e.g., regular and low-fat chips), a common situation in daily consumption. We thus investigated the effect of advance ordering on both food choices and consumption of light and regular vices and compared its impact with that of chronic restrained eating. Two experiments demonstrated that advance ordering did not influence calorie intake or encourage consumers to substitute a regular vice with a light vice. Rather, individual differences in restrained eating consistently predicted both choices and consumed calories. We also discuss the implications of our findings for consumer well-being and advance ordering in the context of lighter-vice options.

Effect of Information on Consumers’ Response to Different Food Categories Enriched With Brewer’s Spent Grain

Brewer’s spent grain (BSG) has been commonly considered as only a waste product, but recent research on its composition has shown that it can be a functional ingredient. The aim of this study was to analyze consumers’ attitude toward different BSG-added food products under informed conditions. BSG-enriched bread, pasta, and chocolate milk were studied exploring two major aspects. First, the eye-tracking technology was used to reveal the effect of different food labels on consumers’ attention and purchase intention. Information on sustainability and on BSG varied among the labels under analysis. The best consumers’ response occurred when the label displayed: the sustainability logo, fiber source claim, and BSG description. The phrase “Malted Barley” as an appellation of BSG was also analyzed, although it did not produce a significant effect on consumers. Second, consumers’ responses to fiber-enriched products and regular products, under informed conditions, were assayed through sensory evaluations. For bread and chocolate milk samples, no significant difference was found in acceptability between the regular and fiber-enriched versions. For pasta, on the other hand, consumers expressed a significant preference in terms of overall liking toward the fiber-enriched version. BSG-enriched products were accepted as much as the regular ones when information was provided, confirming the importance of the fiber source claim and sustainability claims.

Randomized Controlled Trial to Investigate the Effects of Repeated Exposure to Low Added Sugar Snacks Among Children: Choice of Experimental Food Stimuli

ObjectivesWhat we eat during childhood programs food preferences, yet from the age of two years, added sugar intake exceeds recommended levels. We are conducting a trial in which mother-child dyads are randomized to one of two groups that differ in the sweetness and added sugar content of afternoon snacks provided to toddlers and type of educational lessons given to their mothers. The present study describes the methods used to determine the types of snacks proffered to the control and intervention groups during the 4-month exposure period.MethodsWe established a priori that snacks for either group would differ in added sugar and sweetness without the inclusion of candy, low calorie sweeteners, or sugar sweetened beverages and would provide similar energy (300 kcal) at each snack occasion. We developed two menus. In the first menu, every snack occasion contained at least one food or beverage item, often made by the same manufacturer, for which there was a regular sugar version for control group and low-sugar version for the intervention group. In the second menu, we put less emphasis on matching the types of snacks for the two groups. Rather, we focused on the added sugar and salt content of the snacks and we provided additional snack occasions (∼4/month) of fresh fruit for the intervention group. A sensory panel evaluated the sweetness of the snacks using the general labelled magnitude scale.ResultsWhile both menus yielded snacks that differed in sweetness (p < 0.001) and sugar content (p < 0.001), the intervention snacks in the first menu contained twice the amount of sodium than the control snacks in the first menu (p < 0.001). Adding fruit and focusing on the sugar and sodium content per se resulted in the intervention snacks in the second menu containing significantly less sodium than those in the first menu (p < 0.001). Although there was only a one-fold difference between the intervention and control snacks in the second menu, the difference was significant, due in part to more savory snacks for the intervention group (p < 0.001).ConclusionsProviding low-sugar snacks to children requires attention to its salt content, another preferred taste of children. With increasing evidence suggesting the importance of early life experiences on long-term health, this trial will inform future prevention efforts for children.Funding SourcesSupported by NIH Grant R01DC016616.

Impact of cyclic strain accumulation on the tilting behaviour of monopiles in sand: An assessment of the Miner’s rule based on SANISAND-MS 3D FE modelling

Offshore monopiles accumulate permanent tilt under long-lasting cyclic environmental loads. Accurate prediction of monopile tilt is key to assessing their serviceability, and requires a fundamental understanding of loading history effects. While both experimental and numerical studies are shedding light on this matter, this work uses step-by-step implicit 3D FE modelling to investigate loading history effects in the response to cyclic lateral loading of monopiles in sand and to identify links between local soil behaviour and relevant features of global pile behaviour. For this purpose, the recently developed SANISAND-MS model is adopted to achieve a reliable simulation of sand’s cyclic ratcheting. In particular, the validity of an up-scaled Miner’s rule for monopile tilting under multi-amplitude cyclic loading is assessed based on the results of 3D FE parametric analyses, with emphasis on the role played by the engineering idealisation of random environmental loading. The validity of such a rule has been numerically investigated both in terms of local soil element response and global foundation behaviour — for the particular case of a large-diameter monopile. In respect, the effect of the loading history idealisation is presented, and it is concluded that Miner’s rule does not always rigorously apply to all the cases considered herein. The translation of irregular loading histories into a regular version with loading packages sorted in ascending amplitude order is shown to be a reasonable approach, at least when the possibility of cyclic pore pressure build-up is disregarded.

Do people really support conservation? Evidence from China and the United States

Survey studies have consistently shown strong public support for biodiversity conservation, even though conservation regulations often face strong local resistance when they are implemented. This seemingly contradictory phenomenon is due to the fact that previous polls have sought opinion only in the abstract, yet many conservation measures are implemented at the expense of local economic development, and policymakers often face a ‘Conservation-Development Tradeoff’-a policy dilemma that remains understudied by social scientists. To fill this gap, this study conducts one of the first comparative surveys on public support for biodiversity conservation in China and the United States. I measure public support for conservation using two separate question versions online. The ‘regular version’ asks directly about individual support for biodiversity conservation, and the “tradeoff version” asks the same question but in the context of the policy tradeoff. The results show that both American and Chinese citizens are highly supportive of conservation in the abstract. But after they learn about the tradeoff effect, the aggregate support falls sharply, and the Chinese citizens show significantly less support compared to their American counterparts. The survey findings expanded on existing academic research on public attitudes toward conservation policies and can encourage future conservation policymakers to understand the significance of the tradeoff issue, as conventional wisdom may have overestimated public support for biodiversity conservation. Moreover, as China has become a crucial player in global conservation governance, understanding the Chinese public sentiment on the real-world policy dilemma can have important implications for conservation policymaking in the world.

Fair Infinite Lotteries, Qualitative Probability, and Regularity

AbstractA number of philosophers have thought that fair lotteries over countably infinite sets of outcomes are conceptually incoherent by virtue of violating countable additivity. In this article, I show that a qualitative analogue of this argument generalizes to an argument against the conceptual coherence of a much wider class of fair infinite lotteries—including continuous uniform distributions. I argue that this result suggests that fair lotteries over countably infinite sets of outcomes are no more conceptually problematic than continuous uniform distributions. Along the way, I provide a novel argument for a weak qualitative, epistemic version of regularity.

Perceptions of Doctors' Empathy and Patients' Subjective Health Status at an Online Clinic: Development of an Empathic Anamnesis Questionnaire.

ABSTRACTObjectiveMedical doctors’ empathy is known to support patients’ health status after face-to-face clinical visits. However, the role of doctors’ empathy in chat-based encounters is not yet well understood. This study investigates whether patients’ evaluations of doctors’ empathy are associated with their health perceptions after a meeting at an online clinic and whether experiences of empathy could be enhanced by augmenting an automated anamnesis questionnaire completed before the visit.MethodsA total of 209 adult patients agreed to participate in the study. First 103 patients filled out the regular version of the questionnaire (June–August 2019) and then 106 filled out the augmented version of the online anamnesis questionnaire (August–November 2019). Patients’ perceptions of doctors’ empathy were measured with the Consultation and Relational Empathy questionnaire. Patients’ self-perceived health status, potential confounders, and demographic background information were measured via questionnaires.ResultsPatients’ perceptions of doctors’ empathy during a chat-based encounter were associated with patients being less concerned about their symptoms (estimated odds ratios varied between 0.45 and 0.55 depending on the model, p values < .003) and considering their symptoms as less severe (estimated odds ratios = 0.54–0.61, p values < .007), as well as a higher probability of alleviation of symptoms as rated by the patients (estimated odds ratios = 2.16–2.24, p values < .001). Augmenting the anamnesis questionnaire did not affect patient reports on doctors’ overall empathy, but it did have positive effects on specific areas of doctors’ empathy covered by the questionnaire.ConclusionsThese results show that patients’ experience of doctors’ empathy not only is important during face-to-face encounters but also supports patients’ perceptions of health when the interaction is text based. The results also encourage further development of means to support patients’ experiences of empathy during online interaction with medical doctors.

CC-regular topological spaces

A topological space X is called CC-regular if there exists a regular space Y and a bijective function f: X→Y such that f |C : C→f(C) is homeomorphism for any countably compact subspace C of X. We investigate this definition. Some relations with weaker versions of regularity have been studied, as L-regular and C-regular spaces.

Brain oscillation recordings of the audience in a live concert-like setting

There are only a few previous EEG studies that were conducted while the audience is listening to live music. However, in laboratory settings using music recordings, EEG frequency bands theta and alpha are connected to music improvisation and creativity. Here, we measured EEG of the audience in a concert-like setting outside the laboratory and compared the theta and alpha power evoked by partly improvised versus regularly performed familiar versus unfamiliar live classical music. To this end, partly improvised and regular versions of pieces by Bach (familiar) and Melartin (unfamiliar) were performed live by a chamber trio. EEG data from left and right frontal and central regions of interest were analysed to define theta and alpha power during each performance. After the performances, the participants rated how improvised and attractive each of the performances were. They also gave their affective ratings before and after each performance. We found that theta power was enhanced during the familiar improvised Bach piece and the unfamiliar improvised Melartin piece when compared with the performance of the same piece performed in a regular manner. Alpha power was not modulated by manner of performance or by familiarity of the piece. Listeners rated partly improvised performances of a familiar Bach and unfamiliar Melartin piece as more improvisatory and innovative than the regular performances. They also indicated more joy and less sadness after listening to the unfamiliar improvised piece of Melartin and less fearful and more enthusiastic after listening to the regular version of Melartin than before listening. Thus, according to our results, it is possible to study listeners’ brain functions with EEG during live music performances outside the laboratory, with theta activity reflecting the presence of improvisation in the performances.

Almost α-regular spaces

A new version of regularity is introduced as a simultaneous generalization of almost regularity and α-regulaity, and it is called almost α-regularity. We discuss many properties of this a new space and we give some properties that connect this a new space with some other topological spaces, also we present an examples and counter examples that show the relationships between almost α-regular and some other topological spaces.

Complete Hausdorffness and Complete Regularity on Supra Topological Spaces

The supra topological topic is of great importance in preserving some topological properties under conditions weaker than topology and constructing a suitable framework to describe many real-life problems. Herein, we introduce the version of complete Hausdorffness and complete regularity on supra topological spaces and discuss their fundamental properties. We show the relationships between them with the help of examples. In general, we study them in terms of hereditary and topological properties and prove that they are closed under the finite product space. One of the issues we are interested in is showing the easiness and diversity of constructing examples that satisfy supra T i spaces compared with their counterparts on general topology.