Numerical Determination Research Articles

CLASSIFICATION OF COMPANY LIFE CYCLE STAGES: AN AUTOMOTIVE INDUSTRY IN THE CZECH REPUBLIC

Company life cycle models have been the focus of researchers’ attention for decades, resulting in numerous definitions and determination of stages. Managers are striving to make appropriate strategic decisions at the right time to maximize opportunities linked to various life cycle stages. Assessing a company’s life cycle and determining the stage of the cycle allows us to predict a company’s future development and to prevent crises or even the company’s early termination. In recent years, there has been increased interest in the life cycle assessment of products. However, as a corporate life cycle is longer than that of a product, it still definitely deserves attention – mainly in the field of quantitative criteria. The aim of this paper is to propose quantitative variables to determine a company’s life cycle following two requirements: (1) the variables are derived from publicly available financial statements; and (2) the classification method is suitable for a large sample size including non-listed companies in the stock exchange. Our study shows that our three variables (capital expenditures, return on equity, and sales growth) are suitable for stage classification for each firm-year under the condition of following several steps: counting industry quintiles and/or definition of boundaries, score assignment to stages, designing composite score and sample selection. Based on descriptive statistics of each life cycle stage it is possible to assess the variables used in the context of the further strategic direction of the company. To determine the persistence of enterprises in the defined stages, a transition matrix for the four future years was performed, which showed that companies in the growth and maturity stages will be sustained in these two phases in the vast majority of cases. Finally, we discuss the limitations of the study and further research directions.

Equilíbrio em conta-corrente e câmbio real: o caso da manufatura no México, 2001-2019

ABSTRACT In this paper, we follow Bresser-Pereira et al. (2021) and estimate for Mexico a a series of the real exchange rate (RER) that balances the current account for Mexico for the period 2001q1-2019q4. In this process we take into account numerous determinants, including policy variables and financial indicators the evolution of the terms of trade, as well as a proxi for the Balassa-Samuelson effects, inter alia. Our results show that in most of the period analyzed there has been a trend tendency towards overvaluation, with the RER fluctuating above its equilibrium level. With cointegrating methods, and dynamic ordinary least squared (DOLS) techniques, we examined the effects of exchange rate under and overvaluation on manufacturing; disaggregated in three sectors: i) technology intensive, ii) natural resource intensive and iii) labor intensive activities. Overall, our results indicate that the real exchange rate has a significant influence on the rate of expansion of Mexico’s manufacturing real GDP.

Experimental–Numerical Determination of the Effective Bulk Thermal Conductivity of Suspension Bridge Main Cables

Experimental–Numerical Determination of the Effective Bulk Thermal Conductivity of Suspension Bridge Main Cables

Numerical Determination of Thermal Conductivity in Heat Equation under Nonlocal Boundary Conditions and Integral as Over specified Condition

In this article, an inverse problem of finding timewise-dependent thermal conductivity has been investigated numerically. Numerical solution of forward (direct) problem has been solved by finite-difference method (FDM). Whilst, the inverse (indirect) problem solved iteratively using Lsqnonlin routine from MATLAB. Initial guess for unknown coefficient expressed by explicit relation based on nonlocal overdetermination conditions and intial input data .The obtained numrical results are presented and discussed in several figures and tables. These results are accurate and stable even in the presense of noisy data.

Assessing the relaxation of recycled aggregates concrete from free and restrained shrinkage tests

Recycled concrete aggregates (RCA) lead to higher shrinkage of concrete than natural aggregates because of two main reasons: lower elastic modulus and possible shrinkage of RCA. The study aims at quantifying the effects of both phenomena, thus Trisphere model has been chosen as it takes into account the influence of aggregates modulus and shrinkage on the properties of concrete. The existing model has been adapted to determine the elastic modulus and shrinkage of recycled aggregates from the modulus and shrinkage of concrete. The shrinkage of coarse RCA was much lower than the shrinkage of fine RCA, thus the increase in the shrinkage of concrete can be mainly attributed to the reduction in aggregate modulus and variations of composition parameters (W/C, volume of paste). The model also allows estimating the delayed elastic modulus of concrete. The obtained values are compared with the numerical determination of viscoelastic-aging Young's modulus from restrained shrinkage tests (ring tests). The long-term moduli provided by both approaches are consistent for most of studied materials. The relaxation increased with the content of coarse recycled aggregates, but the variation was lower than reported in creep studies. This could be due to lower relative stress level as recycled aggregates also induce lower elastic modulus thus lower stress for a given restraint.

Updates in SASfit for fitting analytical expressions and numerical models to small-angle scattering patterns.

Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. Here, a selection of enhancements and additions to the SASfit program are presented that may be of great benefit to interested and advanced users alike: (a) further development of the technical basis of the program, such as new numerical algorithms currently in use, a continuous integration practice for automated building and packaging of the software, and upgrades on the plug-in system for easier adoption by third-party developers; (b) a selection of new form factors for anisotropic scattering patterns and updates to existing form factors to account for multiple scattering effects; (c) a new type of a very flexible distribution called metalog [Keelin (2016). Decis. Anal. 13, 243-277], and regularization techniques such as the expectation-maximization method [Dempster et al. (1977). J. R. Stat. Soc. Ser. B (Methodological), 39, 1-22; Richardson (1972) J. Opt. Soc. Am. 62, 55; Lucy (1974). Astron. J. 79, 745; Lucy (1994). Astron. Astrophys. 289, 983-994], which is compared with fits of analytical size distributions via the non-linear least-squares method; and (d) new structure factors, especially for ordered nano- and meso-scaled material systems, as well as the Ornstein-Zernike solver for numerical determination of particle interactions and the resulting structure factor when no analytical solution is available, with the aim of incorporating its effects into the small-angle scattering intensity model used for fitting with SASfit.

Exploring the Sustainable Delivery of Building Projects in Developing Countries: A PLS-SEM Approach

Sustainable building approaches should be included at every level of the development process for maximum benefit without jeopardising the structure’s intended usage. However, researchers have paid less attention to how they may be applied to developing nations. This study aims to investigate the numerous determinants of sustainable delivery in the construction industries of developing nations. For this to happen, existing literature was used to inform the development of a closed-ended questionnaire. Consequently, 95 structured questionnaires by building professionals investigated the importance of these factors. As a result, the factor’s structure was determined and confirmed using the study’s partial least square structural equation modelling (PLS-SEM) approach, which was utilised to investigate the connections between these factors. According to the PLS-SEM analysis, the factors most strongly influencing sustainable delivery are those associated with the preparation, followed by evaluation and use factors, respectively. As a result of this research, authorities in Egypt’s building sector will have a road map for implementing sustainability principles to reduce building costs, boost the local ecosystem, and strengthen social cohesion.

Phraseological Use and Development During a Stay Abroad: Exploring Sensitivity to Frequency and Cue Contingency

AbstractUsage‐based approaches to additional‐language acquisition have identified numerous determinants of language learning, two of which were the focus of our study: frequency and cue contingency. Specifically, we examined how an immersion experience may impact sensitivity to these two determinants as reflected in the production of 4,808 pairs of nouns (N) and adjectives (ADJ) by 50 anglophone learners of Spanish and French. We analyzed the use of N/ADJ combinations using mixed linear regressions for frequency and two measures of delta P, a unidirectional measure of lexical association strength reflecting cue contingency. In all three models, we explored the impact of time and four additional variables: task, initial proficiency, target language, and phraseological unit. Our analysis revealed stasis over time. Additionally, our analysis revealed phraseological unit, task, and target language each to be significant in at least one model; initial proficiency did not contribute to significantly predicting phraseological use.

Stiffness contributions of ballast in the context of dynamic analysis of short span railway bridges

Railway bridges are subjected to intensive dynamic loading. In structural calculations, the resulting response is estimated by dynamic calculations. As the basis of these calculations, the system's natural frequencies are to be numerically determined. Various studies have shown that a discrepancy between these measured natural frequencies and the numerical determination often occurs for short-frame bridges. In common practice, the ballast is assumed to be non-contributing to the global structural stiffness. In some cases, rheological models are developed to consider possible ballast stiffnesses based on small-scale model tests. The resulting spring-damper models are based on empirical values and are not directly related to the material behaviour of ballast.This paper discusses the ballast stiffness at the material level using relationships known from soil dynamics. The research shows that the material properties of the ballast can be determined in terms of stress and shear strain dependence. An equivalent ballast stiffness can be determined and considered in dynamic calculations for a known stress state and corresponding superstructure accelerations. The paper presents an approach for determining vertical and horizontal ballast stiffness according to shear strains and superstructure accelerations.This developed approach is validated by experimental tests using a small-scale bending beam and accompanying numerical calculations.Furthermore, a parameter study shows that the stiffness of the ballast does not contribute significantly to the global bending stiffness. Thus, the first bending natural frequency is hardly influenced by the ballast track.

Hybrid between Lemna minor and L. turionifera (L. × japonica, Lemnaceae) in East Europe is more frequent than parental species and poorly distinguishable from them

Biodiversity studies and practical use of duckweeds are impossible without reliable species identification. Despite of clear genetic differentiation of L. minor, L. turionifera and their hybrid L. × japonica, their morphological discrimination is challenging even for professional botanists; consequently, the distribution of the two latter taxa is not precisely known. Although numerous determination keys exist, none of them is based on quantitative analysis of the morphological variation observed in nature. Thus, we aimed to study variation of morphological characteristics most frequently proposed for discrimination between L. minor, L. turionifera and L. × japonica (frond shape and pigmentation, papule presence along the median nerve) on specimens collected in the wild, which were taxonomically identified using molecular tools (intron length polymorphism in the β-tubulin gene). We focused on samples from the poorly studied East Europe, including some from the Russian Far East for comparison. Lemna × japonica appeared to be quite abundant in different regions of East Europe. The Far Eastern occurrences of L. minor and L. × japonica should be carefully verified. Even our limited sampling demonstrated that morphological characters conventionally used for delimitation of L. minor, L. turionifera and L. × japonica do not work in wild populations. Additional studies should be performed for verification of diagnostic value of generative characters. Large-scale genetic screening of Lemna populations in nature is also indispensable to clarify distribution of taxa from the L. minor complex.

Musculoskeletal simulation of elbow stability for common injury patterns.

Elbow stability is derived from a combination of muscular, ligamentous, and bony structures. After an elbow trauma the stability of the joint is an important decision criterion for the subsequent treatment. The decision regarding nonoperative/operative care depends mostly on subjective assessments of medical experts. Therefore, the aim of this study is to use musculoskeletal simulations as an objective assessment tool to investigate the extent to which failure of different stabilizers affects the elbow stability and how these observations correspond to the assessment from clinical practice. A musculoskeletal elbow simulation model was developed for this aim. To investigate the stability of the elbow, varus/valgus moments were applied under 0°, 45°, and 90° flexion while the respective cubital angle was analyzed. This was performed for nine different injury scenarios, which were also evaluated for stability by clinical experts. With the results, it can be determined by which injury pattern and under which flexion angle the elbow stability is impaired regarding varus/valgus moments. The scenario with a complete failure of the medial and lateral ligaments and a fracture of the radial head was identified as having the greatest instability. The study presented a numerical determination of elbow stability against varus/valgus moments regarding clinical injury patterns, as well as a comparison of the numerical outcome with experience gained in clinical practice. The numerical predictions agree well with the assessments of the clinical specialists. Thus, the results from musculoskeletal simulation can make an important contribution to a more objective assessment of the elbow stability.

Improved numerical method for determination of pavement mean texture depth from 3-dimensional digital image

The conventional manual sand-patch method of mean texture depth (MTD) measurement is unsuitable for network level pavement condition monitoring. Relying on 2-D mean linear profile depth (MPD) to estimate 3-D MTD is also unsuitable because MTD-MPD regression relationship varies from one pavement mix type to another. This problem of network level MTD measurements and monitoring can be overcome if MTD could be numerically determined from 3-D digital laser images. All the numerical MTD determination methods proposed by researchers in recent years made a common invalid assumption that the MTD top surface was defined by the high texture peaks of the test surface. This study presents evidence to show that the top surface defining MTD actually lies below the highest peaks of the test surface. Next, applying the concept of planation surface, a novel numerical procedure is proposed to identify a reference surface for MTD calculation by means of a second-derivative plot of peak-height percentiles. The validity of the proposed method was verified experimentally with measured MTD values of both laboratory fabricated specimens and in-service pavements. For four different surface course materials, the errors in the predicted MTD values range from 0.20 to 7.31 %. The proposed method produced improved accuracy in MTD predictions compared with the existing methods which were based on incorrectly assumed MTD top surfaces.

Experimental and Numerical Determination of Strength Characteristics Related to Paraglider Wing with Fourier Transform Infrared Spectroscopy of Applied Materials.

The aim of paper is to determine experimentally and numerically the strength characteristics related to the paraglider wing with Fourier transform infrared spectroscopy of applied materials. The applied method consists in theoretical modeling supplemented by the tests of material parameters. First, the set of 10 lightweight fabrics was selected for the tests; the samples are representative for these structures. The materials were tested using the spectroscopy to determine the FTIR spectra. The samples differ in the content of certain characteristic groups. Air permeability change of the materials was determined for the different pressure drops. The air permeability of almost all the analyzed samples was close to zero with the exception of only one material. The tensile strength and elongation at the break of samples were determined on the testing machine. The paraglider samples were characterized by slightly decreased mechanical properties compared to the parachute fabrics. The material characteristics determined during the tests are the input data for the theoretical analysis. The numerical model of the paraglider wing is based on a 3D geometry from previous research, but the stress, strain, and deformation were determined using the ANSYS Structural program and the finite elements method. To determine the strength correctly, we introduce two basic values: the absolute maximal and the representative values that are the biggest repetitive values of stress, strain, and deformation. The stress value was determined by the main factors: (i) the thinner the material, the bigger the stresses that were accumulated; (ii) the stronger the material, the bigger the stresses that were accumulated. The results are similar for all materials and differ mainly by the values. The biggest stresses were observed inside the material contacting the ribs, whereas the biggest deformation and strain were in the regions between ribs, and the smallest were in the contact areas with the fixed supports. Their highest intensity was observed on the leading edge of the paraglider. We conclude that the obtained stresses were far from the breaking level for the wing.

Femtosecond-comb based 10 MHz-to-optical frequency link with uncertainty at the 10−18 level

The International System of Units (SI) definition of the ‘second’ is likely to be redefined in the optical frequency region in the near future. Therefore, uncertainty reduction in the frequency link between 10 MHz, which is used in the frequency link with an artificial satellite, and the ultrastable laser for observing clock transitions in optical clocks, is an important issue for numerical determination in the new definition and for International Atomic Time operation after the redefinition. We have evaluated all the possible uncertainty factors in the frequency link with a femtosecond comb between 10 MHz and an optical frequency and obtained the lowest uncertainty yet reported of 3.9 × 10−18 by temperature-stabilizing RF multipliers and by using temperature insensitive coaxial cables. Furthermore, we have validated the uncertainty of the frequency link by simultaneously measuring an optical frequency of an identical laser using two femtosecond combs referenced to a common 10 MHz source and confirmed to be consistent with the evaluated uncertainty.

Revealing determinants that affects garlic production in Ethiopia using PRISMA methodology

Today, garlic productivity in Ethiopia is below its potential which is ranked 15 in the world. This is due to numerous determinants that affect garlic production. Therefore, the study’s main objective was to reveal and sum up determinants affecting garlic production in Ethiopia using PRISMA Method. Preferred reporting items for systematic review and meta-analysis checklist s1 table were employed. Universally accredited and indexed high-quality databases and university libraries; specifically, Scopus, PubMed, Science Direct, University of Toronto Library, and Google Scholar were used for retrieving published data (2000–2022). The titles “Garlic” and Ethiopia” were used to retrieve articles. “Microsoft Excel” was used to summarize results. The present study indicated that a total of 12,000 publications from Google scholar, and 51 publications from the University of Toronto library search engine published on the web of science and Scopus were used. A total of 51 publications were chosen as being the most suitable for this paper. Among the 51 publications, 86%, 6%, 6%, and 2% were articles, Newsletter articles, Text resources, and conference proceedings, respectively. Accordingly, a study revealed that the low production of this crop is due to information obtained via a systematic review discussed and categorized as institutional determinants (15.69%), farmers’ characteristics (9.8%), production and management practice (68.63%), and postharvest (5.88%). Institutional; production and management practices are of the major determinants negatively affecting garlic production in Ethiopia. Moreover, research limitations also were revealed. The recommendation of this paper is therefore not general, specifically, each factor has been recommended.

Diffusion and Lyapunov timescales in the Arnold model.

In the present work, we focus on two dynamical timescales in the Arnold Hamiltonian model: the Lyapunov time and the diffusion time when the system is confined to the stochastic layer of its dominant resonance (guiding resonance). Following Chirikov's formulation, the model is revisited, and a discussion about the main assumptions behind the analytical estimates for the diffusion rate is given. On the other hand, and in line with Chirikov's ideas, theoretical estimations of the Lyapunov time are derived. Later on, three series of numerical experiments are presented for various sets of values of the model parameters, where both timescales are computed. Comparisons between the analytical estimates and the numerical determinations are provided whenever the parameters are not too large, and those cases are in fact in agreement. In particular, the case in which both parameters are equal is numerically investigated. Relationships between the diffusion time and the Lyapunov time are established, like an exponential law or a power law in the case of large values of the parameters.

Metasurfaces and Optimal transport

This paper provides a theoretical and numerical approach to show existence, uniqueness, and the numerical determination of metalenses refracting radiation with energy patterns. The theoretical part uses ideas from optimal transport and for the numerical solution we study and implement a damped Newton algorithm to solve the semi discrete problem. A detailed analysis is carried out to solve the near field one source refraction problem and extensions to the far field are also mentioned.

General practice pharmacists’ implementation of advanced clinical assessment skills: a qualitative study of behavioural determinants

BackgroundThe role of General Practice Clinical Pharmacists is becoming more clinically complex. Some are undertaking courses to develop their skillsets.AimTo explore potential behavioural determinants influencing the implementation of skills gained from Advanced Clinical Examination and Assessment courses by General Practice Clinical Pharmacists.MethodThis study used a qualitative methodology with theoretical underpinning. General Practice Clinical Pharmacists in the Scottish National Health Service, having completed an Advanced Clinical Examination and Assessment course, were invited for online dyadic (paired) interviews. Informed written consent was obtained. The interview schedule was developed using the Theoretical Domains Framework and piloted. Interviews were recorded, transcribed verbatim and analysed using a framework analysis. Ethics approval was obtained.ResultsSeven dyadic interviews were conducted. These included fourteen pharmacist participants from eight Health Boards. Three main themes were identified: 1. Factors influencing implementation of advanced clinical skills by pharmacists; 2. Social and environmental influences affecting opportunities for pharmacists in advanced clinical roles; 3. Perceptions of pharmacist professional identity for advanced practice roles. Nine sub-themes provided a depth of insight including; participants reporting courses allowed clinically autonomous practice; participants shared frustration around social and environmental factors limiting implementation opportunities; participants expressed a need for clarification of professional identify/roles within current contractual mechanisms to allow them to fully implement the skills gained.ConclusionThis work identified numerous behavioural determinants related to implementation of advanced clinical skills by pharmacists in general practice. Policy, and review of implementation strategies are urgently required to best utilise pharmacists with these skills.

Strains and Stresses at Welding with Tubular Wires and Swinging the Electric Arc

As it is known, starting with the 19th century, the constructions with metallic strength structure have acquired a wide development. From simple supports for various structures to the most complex constructions, we find metallic elements that must be joined together in various ways. One of the simplest methods, constructive and economic, of joining metallic components of a structure is welding. The study presented in this paper deals with numerical determination of the stress and strain states around welded joints in steel sheets, using the finite element method. The studied sample was manufactured by mechanized welding, in protective gas atmosphere, with tubular wires, and swinging the electric arc. The welding was continuous, made in two layers: root and cover. The finite element method can also be used to study the processes that take place during welding. Important thermal phenomena occur in the weld bead during welding. To obtain reliable results, data describing accurately the behaviour in time of the basic and the addition material are needed. According to well-established parameters of the welding regimes, the welding process was modelled numerically. The results were taken from several areas of the sample, both in the base material (sheet metal) and in the addition material (weld bead). Stresses and strains were analysed at various moments of time during the welding process, both for the first welding layer (root) and the second welding layer (cover).

New Numerical and Statistical Determination of Probes’ Arrangement in Turbo-machinery

New Numerical and Statistical Determination of Probes’ Arrangement in Turbo-machinery