Deviation Equation Research Articles

Establishing inventory measurements using intermittent demand forecasting

Demand forecasting is a fundamental element in industrial problems. Forecasts are crucial for accurately estimating intermittent demand to establish inventory measurements. The demand estimation by the Croston method gives less accurate values, which increases the standard deviation value. This increase indicates that the forecasted method is an inappropriate method of intermittent demand data because of the zero values. However, real data were adopted in an industrial sector for three years with constant lead-time. Furthermore, an integration of Bernoulli distribution and geometric distribution has been done to establish the new formulation, then extracting the mean equation and the standard deviation equation of intermittent demand during lead-time. Relying on it, the optimal quantity of safety stock and reorder levels have been obtained. Furthermore, the proposed modified forecasting method was evaluated based on the criteria of CV and the results that obtained gives a less ratio dispersion of data thus accurate results. These procedures are very important to the industrial sectors in drawing future inventory policies.

The Relationship Between Physical Exercise and Mobile Phone Addiction Tendency of University Students in China: A Moderated Mediation Model.

This study aims to explore the relationship between physical exercise (PE), self-control (SC), physical exercise atmosphere (PEA), and mobile phone addiction tendency (MPAT) among Chinese university students. Through the quota sampling, 1,433 students complied with the requirements were surveyed from 10 universities in China. PE, SC, PEA, and MPAT were assessed using standard scales. For data analysis, common method deviation test, mean number, standard deviation, correlation analysis and structural equation model analysis were carried out in turn. The results showed PE and MPAT were negatively related (r = –0.158, p < 0.05); PE significantly positively predicted SC (β = 0.082, t = 3.748, p < 0.01), and SC significantly negatively predicted MPAT (β = –0.743, t = –19.929, p < 0.01). Bootstrap method was used to test the mediating effect of SC. The results showed that 95% confidence interval did not include 0. After adding the mediating variable of SC, PE did not significantly negatively predict the tendency of MPAT (β = –0.027, t = –1.257, p > 0.05). The interaction item PEA and SC could significantly positively predict the tendency of MPAT (β = 0.165, t = 2.545, p < 0.05). In the high PEA group, SC had a significant negative predictive effect on the tendency of MPAT (β = –0.665, t = –14.408, p < 0.01); However, in the low PEA group, the negative predictive effect was stronger (β = –0.834, t = –15.015, p < 0.01). The present study shows that PE significantly negatively predicted the tendency of MPAT, and SC played a complete mediating role in the relationship between PE and MPAT; The second half of the indirect effect of PE and MPAT was regulated by the PEA. The PEA will enhance the influence of SC on MPAT, but the high PEA will increase the level of MPAT of individuals at a very high level of SC.

Factors affecting use of information communication technologies among extension agents in North-East, Nigeria

The study identified the levels of ICT use, awareness, accessibility, perceived organizational support, assessed the perception of the respondents on problems in using ICTs for agriculture extension work and, clarifies the relationships between awareness, accessibility, perceived organizational support, and use of ICTs. Data were collected through the use of a questionnaire distributed to 254 respondents using a multi-stage sampling and stratified sampling procedures. Mean, frequency, standard deviation and structural equation modelling in analysis of morement structure (AMOS) was used. Findings revealed that levels of ICT use (x̄ = 3.43), awareness (x̄ =3.40) accessibility (x̄ 3.66), and perceived organizational support (x̄ 3.574) were moderates. The high cost of ICT garget (x̄ =4.71), poor electricity supply (x̄ =4.69), lack of training (x̄ =4.63), ICT illiteracy (x̄ =4.61), outdated contents (x̄ =4.61), inability to use ICT (x̄ =4.55) and network issue (x̄ =4.34) were the critical problems in using ICTs in extension work. There was relationship between awareness, accessibility and motivation with ICT adoption among extension agents. Governments should design a policy that will focus on awareness, training, access to ICTs among the extension agents, provide an alternative source of power, this will enable them to remain within the system and also increase their usage of ICTs in extension service delivery.

Deviation of non-radial geodesics in a static spherically symmetric spacetime

The article generalizes the description of tidal forces to the case of geodesics with nonzero angular momentum in the metric of static spherically symmetric black holes. We show that the geodesic deviation equation can be diagonalized even with non-radial free motion of a test body in the gravitational field. We present expressions for the spatial components of the tidal force in a spherically symmetric metric. We also solve geodesic deviation equation in the Schwarzschild metric and demonstrate how the presence of angular momentum and its magnitude affect the solution.

Kundt wave geometries in Eddington-inspired Born-Infeld gravity: New solutions and memory effects

We explore memory effects for novel Kundt wave spacetimes in the recently proposed Eddington-inspired Born-Infeld (EiBI) theory of gravity. First, we construct new, exact Kundt wave geometries in this theory for two different matter sources--(i) generic matter designed to satisfy the field equations as well as energy conditions, and (ii) electromagnetic field. For both sources we find that the EiBI theory parameter $\kappa$ couples only with the nonradiative part of the physical metric solution. Thereafter, we solve the geodesic and the geodesic deviation equations, in the above spacetimes with the aim of arriving at memory effects. This analysis is carried out numerically and reveals unique memory features depending on the type of matter source present and the signature of the spacetime scalar curvature. The role of $\kappa$ in influencing the memory effect, for a given background spacetime, is also noted. Thus, apart from providing novel radiative solutions in EiBI gravity, we also show how different matter configurations are responsible for distinct memory characteristics.

SENIOR FITNESS TEST: REFERENCE CURVES FOR POLISH WOMEN OVER 60 YEARS OF AGE

Background Although population aging is a natural process, it poses many social, economic, and health challenges. It is important for older adults to maintain adequate functional fitness for as long as possible to live independently and autonomously. Presenting reference values of functional fitness on a continuous basis (rather than in 5-year periods as it is the case in the standards for SFT) is a better approach. It provides more insights into changes that occur in functional fitness. The aim of the study was to develop reference curves for fitness tests constituting the Senior Fitness Test for Polish women over 60 years of age who move independently. Methods The study examined 833 women aged over 60 years (m ± SD; 67.42 ± 6.88). The Senior Fitness Test, consisting of 6 fitness tests, was used to evaluate functional fitness. The entire set of data was sorted by the age of participants, numbered, and assorted into overlapping sets. Finally, 17 sets were obtained. The equations for means and standard deviations vs. age were computed for all sets of variables. Results Based on the results of the fitness tests and using appropriate equations, 6 percentile grids were developed for women over 60 years of age. Conclusion The percentile grids developed for individual SFT tests may be an important tool for assessing individual functional fitness in the population of Polish women over 60 years of age. The use of the percentile girds allows for changes in fitness levels over the years to be conveniently illustrated.

Factors Influencing the Intentions to Adopt Technology of the Broiler Farmer in Livestock Region 3, Thailand

This research aimed to study the types and influence of mindsets, performance expectancy, effort expectancy, social influence and facilitating conditions on farmers' intention to adopt a technology. The research participants were 110 broiler farmers in livestock region 3. The research used a questionnaire to collect quantitative data and analyse the data using frequency, percentage, mean, standard deviation, correlation coefficient and structural equation modeling with maximum likelihood estimation to analyse path coefficienct and structural relationships. The result showed that most of the participants have a growth mindset more than a fixed mindset. Performance expectancy, effort expectancy, social influence and facilitating conditions have directly affected boiler farmers' intention to adopt the technology. Effort expectancy has a total effect on attitude toward using technology. Interestingly, facilitating conditions have shown the most considerable influence on attitude toward adopting the technology. Mindsets have an influence on effort expectancy and facilitating conditions.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Most broiler farmers in livestock region 3 possess a growth mindset than a fixed mindset&#x0D; Performance expectancy, effort expectancy, social influence and facilitating conditions have direct effect on boiler farmers' intention to adopt the technology&#x0D; Mindsets influence farmers' perception of effort expectancy and facilitating conditions of adopting the technology&#x0D;

Structural Equation Modeling of OTOP Entrepreneur Improvement to Build Sustainable Competitive Opportunity in The Market

The objectives of this study were to analyze and develop a structural equation modeling of OTOP entrepreneur improvement to build sustainable competitive opportunity in the market. A quantitative research methodology was used in this study, the sample consisted of 286 OTOP entrepreneurs of Tak Bai District, Narathiwat Province. Questionnaires were used to collect data, which were analyzed using frequency, percentage, arithmetic mean, standard deviation, and Structural Equation Modeling (SEM). The results of the research can be summarized as follows: 1) the guideline of OTOP entrepreneur improvement in Phraiwan Subdistrict, Tak Bai District, Narathiwat Province, the overall mean is at a high level. The aspect with the highest average was building the competitive advantages, followed by product development, the lowest average was business network; 2) the structural equation modeling of OTOP entrepreneur improvement to build sustainable competitive opportunity in the market; the factors that affect the OTOP entrepreneur development to build competitive opportunity, entrepreneurial potential development, competitiveness enhancement, which had a direct causal effect on the guideline of OTOP entrepreneur improvement.

Geodesic deviation equation in [formula omitted]-gravity

In the present paper we study the Geodesic Deviation Equation (GDE) in the modified f(Q)-gravity theories. The formulation of GDE in General Relativity in the case of the homogeneous and isotropic Friedman–Lemaître–Robertson–Walker (FLRW) spacetime is briefly discussed and then extended in modified f(Q)-gravity using its covariant counterpart. The generalized Mattig relation is obtained. Finally, an equivalent expression to the Dyer–Roeder equation in General Relativity in the case of f(Q)-gravity is presented.

Speckle Tracking Analysis to Evaluate the Size, Shape, and Function of the Atrial Chambers in Normal Fetuses at 20-40 Weeks of Gestation.

The purpose of this study was to use speckle tracking analysis to evaluate the size, shape, and function of the atrial chambers in normal fetuses and develop a z-score calculator that can be used in future studies in fetuses at risk for cardiovascular disease. The control group consisted of 200 normal fetuses examined between 20 and 40 weeks of gestation in which speckle tracking analysis of right (RA) and left (LA) atrial chambers was performed. The atrial end-diastolic and end-systolic endocardial borders for each chamber were identified from which measurements of atrial length, width, area, and volume were computed. Equations were derived using fractional polynomial regression analysis to compute z-score equations. The LA end-diastolic volume, RA and LA end-diastolic area, length, base width, and mid-chamber widths increased with gestational age and fetal size. Left atrial emptying and ejection volumes increased with gestational age and fetal size. The fractional area change was significantly less for the RA than the LA. The LA base and mid-chamber fractional shortening were significantly greater than the RA. There was a significant difference between the RA and LA global contractile strain. Mean and standard deviation equations for each of the measurements described in this study were computed to create a z-score calculator that can be utilized in the clinical environment when evaluating fetuses with suspected atrial pathology that could alter the size, shape, and function of the atrial chambers.

Exact models of pure radiation in R2 gravity for spatially homogeneous wave-like Shapovalov spacetimes type II

Presented are exactly integrable models with pure radiation in R2 gravity with a cosmological constant related to wave-like Shapovalov spacetimes type II. Spatially homogeneous models of Shapovalov spacetimes were considered. The obtained solutions belong to spaces of type III according to the Bianchi classification and of type N according to the Petrov classification. For the models under consideration, exact solutions for the equations of motion of test particles are obtained in the Hamilton–Jacobi formalism. For the obtained exact models, solutions of the geodesic deviation equations are obtained.

Strong gravitational lens image of the M87 black hole with a simple accreting matter model

ABSTRACT We study simulated images generated from an accretion disc surrounding the supermassive black hole hosted in the nearby galaxy M87. We approach the problem employing very simple accreting models inspired from magnetohydrodynamical simulations and introducing a new recipe for dealing with the combined integration of the geodesic and geodesic deviation equations in Kerr space–time, which allows for a convenient and efficient way to manage the system of equations. The geometry of the basic emission model is given by a two-temperature thin disc in the equatorial plane of the black hole supplemented by an asymmetric bar structure. We show that this configuration permits to generate the most salient features appearing in the EHT Collaboration images of M87 with impressive fidelity.

Age- and sex-related profiles for macro, macro/micro and microvascular reactivity indexes: Association between indexes and normative data from 2609 healthy subjects (3-85 years).

Vascular reactivity (VR), defined as blood vessels’ capability to actively modify the diameter and flow resistances can be non-invasively assessed analyzing vascular response to forearm occlusion. Several VR indexes can be quantified: (i) ´microvascular´, which consider variables that depend almost exclusively on changes in distal resistances, (ii)´ macrovascular´, that evaluate the changes in brachial artery (BA) diameter, adjusting for blood flow stimulus, and (iii) ´macro/micro´, whose values depend on the micro and macrovascular response without discriminating each one´s contribution. VR indexes could not be associated. Many VR indexes have been used without availability of adequate normative data (reference intervals, RIs). Aims: (1) to evaluate macro, macro/micro and micro VR indexes obtained in a cohort of healthy children, adolescents and adults, (2) to evaluate the association between VR indexes, (3) to determine the need for age and/or sex-specific RIs, and (4) to define RIs for VR indexes. Methods: Ultrasound (B-mode/Doppler) and automatic computerized analysis were used to assess BA diameter, blood flow velocity and distal resistances, at rest and in conditions of decreased and increased blood flow. Macro, macro/micro and micro VR indexes were quantified (n = 3619). RIs-subgroups were defined according to European Reference Values for Arterial Measurements Collaboration Group (n = 1688, 3–84 years) and HUNT3-Fitness Study Group (n = 2609, 3–85 years) criteria. Mean value and standard deviation equations were obtained for VR indexes. The need for age or sex-specific RIs was analyzed. Percentile curves were defined and data were compared with those obtained in other populations. Conclusion: Macro and macro/micro VR indexes showed no association (or it was very weak) with microvascular indexes. Age- and sex-related profiles and RIs for macro, macro/micro and micro VR indexes were defined in a large population of healthy subjects (3–85 y). Equations for mean, standard deviation and percentiles values (year-to-year) were included in text and spreadsheet formats.

Tidal forces in Kottler spacetimes

The article considers tidal forces in the vicinity of the Kottler black hole. We find a solution of the geodesic deviation equation for radially falling bodies, which is determined by elliptic integrals. And also the asymptotic behavior of all spatial geodesic deviation vector components were found. We demonstrate that the radial component of the tidal force changes sign outside the single event horizon for any negative values of the cosmological constant, in contrast to the Schwarzschild black hole, where all the components of the tidal force are sign-constant. We also find the similarity between the Kottler black hole and the Reissner–Nordström black hole, because we indicate the value of the cosmological constant, which ensures the existence of two horizons of the black hole, between which the angular components of the tidal force change sign. It was possible to detect non-analytical behavior of geodesic deviation vector components in anti-de Sitter spacetime and to describe it locally.

Application of Hydrophilic–Lipophilic Deviation Equations to the Formulation of a Mixed‐Surfactant Washing Agent for Crude Rice Bran Oil Removal from Spent Bleaching Earth

AbstractIn Thailand, spent bleaching earth (SBE) (20–40 wt.% remaining oil), an industrial waste from edible oil refineries, has usually been disposed of by improper landfilling at industrial sites. This study aims to formulate microemulsion‐based washing solutions from mixed surfactants for cleaning SBE contaminated with crude rice bran oil using the hydrophilic–lipophilic deviation (HLD) concept. Binary nonionic‐anionic surfactant mixtures consisting of System A (Dehydol LS3TH‐Levenol WX), System B (Dehydol LS5TH‐Levenol WX), and System C (Dehydol LS7TH‐Levenol WX) were formulated for use as microemulsion‐based washing formulations. A HLDmixed equation extended with the excess free energy term (GEX/RT) was developed and proposed for predicting the optimum salinity. The optimum salinities obtained from the HLDmixed equation were close to those obtained from the phase behavior. In the SBE washing study, the mixed‐surfactant systems showed a washing efficiency of 90% with low surfactant adsorption capacity on bleaching earth (qmax = 0.01–0.03 mol g−1). The mixed surfactants showed improved washing performance compared to that of the single‐surfactant system. This work highlights the utility of using the HLD concept in designing microemulsion‐based washing formulations from surfactants for the removal of vegetable oil from SBE.

Varying without varying: reparameterizations, diffeomorphisms, general covariance, Lie derivatives, and all that

The standard way of deriving Euler–Lagrange (EL) equations given a point particle action is to vary the trajectory and set the first variation of the action to zero. However, if the action is (i) reparameterization invariant, and (ii) generally covariant, I show that one may derive the EL equations by suitably nullifying the variation through a judicious coordinate transformation. The net result of this is that the curve remains fixed, while all other geometrical objects in the action undergo a change, given precisely by the Lie derivatives along the variation vector field. This, then, is the most direct and transparent way to elucidate the connection between general covariance, diffeomorphism invariance, and Lie derivatives, without referring to covariant derivative. I highlight the geometric underpinnings and generality of above ideas by applying them to simplest of field theories, keeping the discussion at a level easily accessible to advanced undergraduates. As non-trivial applications of these ideas, I (i) derive the geodesic deviation equation using first order diffeomorphisms, and (ii) demonstrate how they can highlight the connection between canonical and metric stress–energy tensors in field theories.

Gravitational waves in a closed spacetime via deviation equation

Within the closed universe, we obtain the amplitude and frequency of gravitational waves in the terms of discrete wave numbers, wave propagation time, and cosmological constant using the deviation equation in the first-order perturbed metric. We demonstrate that the cosmological constant effect on GWs is only seen in the early universe. Also, by considering the time evolution of a gravitational wave in a closed spacetime, we investigate its effect on a circle of nearby massless particles, which will be compared with this case in the flat spacetime. Expanding the universe has effective damping on GWs; thus, we suggest it can be used as a tool to characterize the large-scale curvature of the universe.

Bio-based dispersants for fuel oil spill remediation based on the Hydrophilic-Lipophilic Deviation (HLD) concept and Box-Behnken design

The high density and viscosity of fuel oil leads to its prolonged persistence in the environment and causes widespread contamination. Dispersants with a low environmental impact are necessary for fuel oil spill remediation. This study aimed to formulate bio-based dispersants by mixing anionic biosurfactant (lipopeptides from Bacillus subtilis GY19) with nonionic oleochemical surfactant (Dehydol LS7TH). The synergistic effect of the anionic-nonionic surfactant mixture produced a Winsor Type III microemulsion, which promoted petroleum mobilization. The hydrophilic-lipophilic deviation (HLD) equations for ionic and nonionic surfactant mixtures were compared, and it was found that the ionic equation was applicable for the calculation of lipopeptides and Dehydol LS7TH concentrations. The best formula contained 6.6% w/v lipopeptides and 11.9% w/v Dehydol LS7TH in seawater, and its dispersion effectiveness for bunker fuels A and C was 92% and 78%, respectively. The application of bio-based dispersants in water sources was optimized by Box-Behnken design. The efficiency of the bio-based dispersant was affected by the dispersant-to-oil ratios (DORs) but not by the water salinity. A suitable range of DORs for different oil contamination levels could be identified from the response surface plot. The dispersed fuel oil was further degraded by adding an oil-degrading bacterial consortium to the chemically enhanced water accommodated fractions (CEWAFs). After 7 days of incubation, the concentration of fuel oil was reduced from 3692 mg/L to 356 mg/L (88% removal efficiency). On the other hand, the abiotic control removed less than 40% fuel oil from the CEWAFs. This bio-based dispersant had an efficiency comparable to that of a commercial dispersant. The process of dispersant formulation and optimization could be applied to other surfactant mixtures.

Mean Square Geodesic Deviation in the Zeldovich Problem on Light Propagation in a Universe with Inhomogeneities

In 1964, Ya.B. Zeldovich formulated the problem of light propagation in the Universe under the influence of inhomogeneities. It is reduced to describing the divergence of two close geodesics in a Riemannian space and is described by the geodesic deviation equation (Jacobi equation) with the curvature along the geodesic line varying randomly. Assuming the curvature to be constant on segments of small but finite length, the problem is reduced to studying the product of random matrices and makes it possible to apply the appropriate well-developed mathematical theory, which, however, did not allow calculating the mean-square growth rate of the geodesic deviation. In our paper, we propose a way to solve this problem by introducing a bilinear quantity, one component of which coincides with the square of the Jacobi field. The system of first-order differential equations for the bilinear quantity is explicitly written out, and the solution, same as the growth rate, is again expressed through the product of matrices. Such a technique can be used in the study of a wide range of problems and is naturally generalized to higher-order moments.

Nonlocal tidal effects of the moon and numerical estimation of the secular drift rate for a GPS satellite

In this study, we have analyzed several geometrical aspects of the concept of nonlocal-in-time kinetic energy by deriving the extended geodesic and geodesic deviation equations which are the basic stone to analyze tidal and lunar gravitational forces. We have used these equations to study nonlocal tidal effects of the moon. It was observed that nonlocality-in-time generates higher-order corrections to the gravitational tidal field and hence results on a modification of the drift rate of the moon. We have evaluated the maximal secular drift rate for a GPS satellite due to the tidal potential and compared the results with near Earth missions obtained from the Space-Time Explorer and QUantum Equivalence Space Test space mission and some recent relativistic studies. The numerical estimate of nonlocal-in-time parameter is obtained, although it is small, it proves that nonlocality-in-time may have besides the kinetic aspect a geometrical feature.