The weak solvability of the steady problem modelling the flow of a viscous incompressible heat-conductive fluid through the profile cascade

2017 ◽  
Vol 27 (7) ◽  
pp. 1451-1466 ◽  
Author(s):  
Tomáš Neustupa
Keyword(s):  
Content Type ◽  
Special Boundary Condition ◽  
Fixed Point Principle ◽  
Spatially Periodic ◽  
Periodical Problem ◽  
The Mathematical Model ◽  
Schauder Fixed Point ◽  
Practical Implications ◽  
Weak Solvability ◽  
Periodic Plane

Purpose The paper aims to theoretically study the mathematical model of a steady flow of a heat-conductive incompressible viscous fluid through a spatially periodic plane profile cascade. Design/methodology/approach Reduction of the infinite periodical problem to one period. Leray-Schauder fixed point principle was used. Findings This study proves the existence of a weak solution for arbitrarily large given data (i.e. the inflow velocity and the acting specific body force). Practical implications The author proposed a special boundary condition on the outflow of the domain not only for the velocity and pressure but also for the temperature. Originality/value To the author’s knowledge, the problem has not been studied earlier. More detailed overview is given in the paper in the first part.

Wind-driven land-yacht robot mathematical modeling and verification

2016 ◽  
Vol 43 (1) ◽  
pp. 77-90 ◽  
Author(s):  
Jiqing Chen ◽  
Shaorong Xie ◽  
Jun Luo ◽  
Hengyu Li
Keyword(s):  
Mathematical Model ◽  
Experimental Tests ◽  
Outer Planet ◽  
Mechanism Analysis ◽  
Content Type ◽  
The Antarctic ◽  
The Mathematical Model ◽  
The Given ◽  
Practical Implications ◽  
Wind Resources

Purpose – The purpose of this paper was to solve the shortage of carrying energy in probing robot and make full use of wind resources in the Antarctic expedition by designing a four-wheel land-yacht. Land-yacht is a new kind of mobile robot powered by the wind using a sail. The mathematical model and trajectory of the land-yacht are presented in this paper. Design/methodology/approach – The mechanism analysis method and experimental modeling method are used to establish a dual-input and dual-output mathematical model for the motion of land-yacht. First, the land-yacht’s model structure is obtained by using mechanism analysis. Then, the models of steering gear, servomotors and force of wing sail are analyzed and validated. Finally, the motion of land-yacht is simulated according to the mathematical model. Findings – The mathematical model is used to analyze linear motion and steering motion. Compared with the simulation results and the actual experimental tests, the feasibility and reliability of the proposed land-yacht modeling are verified. It can travel according to the given signal. Practical implications – This land-yacht can be used in the Antarctic, outer planet or for harsh environment exploration. Originality/value – A land-yacht is designed, and the contribution of this research is the development of a mathematical model for land-yacht robot. It provides a theoretical basis for analysis of the land-yacht’s motion.

Novel step-down topologies of star-connected autotransformer

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
JiaRong Wang ◽  
Bo He ◽  
XiaoQiang Chen
Keyword(s):  
Design Methodology ◽  
Voltage Regulation ◽  
Content Type ◽  
Harmonic Reduction ◽  
Modeling Analysis ◽  
Step Down ◽  
The Mathematical Model ◽  
Practical Implications ◽  
Theoretical Results ◽  
Equivalent Capacity

Purpose This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Two new symmetrical step-down topologies of star-connected autotransformers are proposed in this paper. Taking the equivalent capacity as the main parameter, the obtained topologies are modeled and analyzed in detail. Design/methodology/approach This paper adopts the research methods of design, modeling, analysis and simulation verification. First, the star-connected autotransformer is redesigned according to the design objective of symmetrical step-down topology. In addition, the mathematical model of two topologies is established and a detailed theoretical analysis is carried out. Finally, the theoretical results are verified by simulation. Findings Two symmetrical star-connected autotransformer step-down topologies are designed, the winding configurations of the corresponding topology are presented, the step-down ranges of these three topologies are calculated and the influence of step-down ratio on the equivalent capacity of autotransformer are analyzed. Through analysis, the target step-down topologies are obtained when the step-down ratio is [1.1, 5.4] and [1.1, 1.9] respectively. Research limitations/implications Because the selected research object is only a star-connected autotransformer, the research results may lack generality. Therefore, researchers are encouraged to further study the topologies of other autotransformers. Practical implications This paper includes the implications of the step-down ratio on the equivalent capacity of autotransformers and the configuration of transformer windings. Originality/value The topologies designed in this paper enable star-connected autotransformer in the 12-pulse rectifier to be applied in step-down circumstances rather than situations of harmonic reduction only. At the same time, this paper provides a way that can be used to redesign the autotransformer in other multi-pulse rectifier systems, so that those transformers can be used in voltage regulation.

Novel symmetrical step-down topologies of zigzag autotransformer

Circuit World ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 231-256
Author(s):  
JiaRong Wang ◽  
XiaoQiang Chen
Keyword(s):  
Mathematical Model ◽  
Main Parameter ◽  
Design Methodology ◽  
Content Type ◽  
Modeling Analysis ◽  
Step Down ◽  
The Mathematical Model ◽  
Practical Implications ◽  
Theoretical Results ◽  
Equivalent Capacity

Purpose This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Three new symmetrical step-down topologies of zigzag autotransformer are proposed in this paper. Taking the equivalent capacity as the main parameter, the obtained topologies are modeled and analyzed in detail. Design/methodology/approach This paper adopts the research methods of design, modeling, analysis and simulation verification. First, the zigzag autotransformer is redesigned according to the design objective of symmetrical step-down topology. Second, the mathematical model of the designed topology is established, and the detailed theoretical analysis is carried out. Finally, the theoretical results are verified by simulation. Findings Three symmetrical zigzag autotransformer step-down topologies are designed, the winding configurations of the corresponding topology are presented, the step-down ranges of these three topologies are calculated and the influence of step-down ratio on equivalent capacity of autotransformer is analyzed. Through analysis, the target step-down topologies are obtained when the step-down ratio is [0.969, 1.414] and [1.414, 8]. Research limitations/implications Because the selected research object is only zigzag autotransformer, the research results may lack generality. Therefore, researchers are encouraged to further study topologies of other autotransformers. Practical implications This paper includes the implications of step-down ratio on the equivalent capacity of autotransformer and the configuration of transformer windings. Originality/value The topologies designed in this paper enable zigzag autotransformer to be applied in step-down circumstances.

Relationship between washing ratio and chromatic aberration

2020 ◽  
Vol 49 (3) ◽  
pp. 223-227
Author(s):  
Xuemei Ding ◽  
Fenjuan Shao ◽  
Yutong Han ◽  
Xiongying Wu
Keyword(s):  
Rotation Speed ◽  
Chromatic Aberration ◽  
Impact Factors ◽  
Color Fastness ◽  
Content Type ◽  
The Social ◽  
Washing Efficiency ◽  
The Mathematical Model ◽  
The Relationship ◽  
Practical Implications

Purpose Denim, a common fade fabric, can present different degrees of fade under different washing conditions. The phenomenon is similar to the washing efficiency. This study aims to discuss the relationship between impact factors and washing efficiency as well as the color fastness. Design/methodology/approach JMP software was used to design different experiments and 40 experimental groups were obtained. Then Statistical Package for the Social Sciences was used to analyze the results about washing efficiency and chromatic aberration. Findings Results showed that washing temperature, washing time and rotation speed have an effect on color fastness after washing in turn. In a certain range, when washing temperature, washing time or rotation speed increases, color fastness gradually increases as well. These three washing parameters work on washing efficiency as well. After setting and analyzing the mathematical model, the R² between the three washing parameters and washing efficiency is 0.855 and the R² between the three washing parameters and the post-wash chromatic is 0.849. There is a correlation between “Washing Efficiency of Sebum RM (P)” and “Post-wash Chromatic aberration (Q)”. Practical implications Denim could be used in some tests in laboratories instead of sebum standard stain cloth. Originality/value This paper provides an indirect research and feasible method for exploring a new object instead of the standard pollution cloth in the test of related textile study in the future.

Testing and predicting of yarn pull-out in aroma-textile

2017 ◽  
Vol 29 (4) ◽  
pp. 566-577 ◽  
Author(s):  
Salvinija Petrulyte ◽  
Deimante Plascinskiene ◽  
Donatas Petrulis
Keyword(s):  
Well Being ◽  
Woven Fabrics ◽  
Content Type ◽  
Pull Out ◽  
Mathematical Equations ◽  
The Difference ◽  
Good Relation ◽  
Fabric Construction ◽  
The Mathematical Model ◽  
Practical Implications

Purpose The purpose of this paper is to predict the pull-out force of loop pile of ramie/cotton terry woven fabrics treated with aroma-microcapsules as well as to understand and to interpret the pull-out behaviour developing the mathematical model. Design/methodology/approach The displacements and forces associated with pulling a yarn from different structures of fabrics were determined. Regression analysis and factorial designs were performed. Findings The yarn pull-out behaviour of terry fabric is highly dependent on the applied treating and demonstrated various extents of variability under the different pulling distances. The character of yarn pull-out is periodic and depends on fabric construction. The difference between the resistance to pile loop extraction for the grey and modified terry fabrics depends on the changed fabric’s structure. The existence of good relation between binder’s concentration and resistance to pile loop extraction of terry fabric was proved. Practical implications The study enables to forecast important loop feature for terry aroma-textiles: to be securely held in the place preventing loop pulling. Originality/value The assessment of the influence of fabric’s weft density and binder’s concentration for the yarn pull-out of terry aroma-textile was proposed. The research developed analysis and empiric mathematical equations suitable for predicting of displacements and forces related to pulling phenomenon as well as designing new multifunctional terry fabrics with resistance to pile loop extraction required. The received knowledge could enlarge the base of information needful for design of new products for clothing, home textile and healthcare/well-being applications as well.

Analyses of peg‐hole jamming in automatic assembly machines

2011 ◽  
Vol 31 (4) ◽  
pp. 358-362 ◽  
Author(s):  
Ryspek Usubamatov ◽  
K.W. Leong
Keyword(s):  
Mathematical Model ◽  
Boundary Condition ◽  
Design Methodology ◽  
Manufacturing Industry ◽  
Critical Depth ◽  
Assembly Process ◽  
Automatic Assembly ◽  
Content Type ◽  
The Mathematical Model ◽  
Practical Implications

PurposeThe purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.Design/methodology/approachThe mathematical model of the jamming of the peg‐hole type parts in assembly process was performed and its boundary conditions, which lead to jamming, defined.FindingsThe equation of the critical angles of declination for the peg, which leads to the peg‐hole jam, was derived. The boundary condition of the angles of declination and the depth of the peg insertion into the hole were defined.Research limitations/implicationsA mathematical model is developed for rigid parts with a hole and for the peg clamped in the rigid assembly mechanisms. The research has not considered flexible deformations and stiffness of the assembly mechanisms, which result in the peg's declination in the assembly process.Practical implicationsThe results are represented in the form of the peg's critical angles of declination and critical depth of insertion into the hole, which leads to jamming of the peg‐hole type parts to be assembled. On the basis of the obtained results, it is possible to formulate the tolerances of the declination angles for the assembly mechanisms, which clamp the peg‐type parts.Originality/valueThe proposed method calculating the critical angles of the peg's declination and critical depth of the peg's insertion into the hole for assembly of the peg‐hole type parts, enables one to increase the reliability of the assembly process in the manufacturing industry.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

Welcome to the marriage of human capability and artificial intelligence

2019 ◽  
Vol 19 (1) ◽  
pp. 10-14
Author(s):  
Ryan Scott ◽  
Malcolm Le Lievre
Keyword(s):  
Artificial Intelligence ◽  
Team Building ◽  
Workplace Change ◽  
Content Type ◽  
The Future ◽  
Human Capability ◽  
Mind Set ◽  
Future Work ◽  
Crucial Part ◽  
Practical Implications

Purpose The purpose of this paper is to explore insights methodology and technology by using behavioral to create a mind-set change in the way people work, especially in the age of artificial intelligence (AI). Design/methodology/approach The approach is to examine how AI is driving workplace change, introduce the idea that most organizations have untapped analytics, add the idea of what we know future work will look like and look at how greater, data-driven human behavioral insights will help prepare future human-to-human work and inform people’s work with and alongside AI. Findings Human (behavioral) intelligence will be an increasingly crucial part of behaviorally smart organizations, from hiring to placement to adaptation to team building, compliance and more. These human capability insights will, among other things, better prepare people and organizations for changing work roles, including working with and alongside AI and similar tech innovation. Research limitations/implications No doubt researchers across the private, public and nonprofit sectors will want to further study the nexus of human capability, behavioral insights technology and AI, but it is clear that such work is already underway and can prove even more valuable if adopted on a broader, deeper level. Practical implications Much “people data” inside organizations is currently not being harvested. Validated, scalable processes exist to mine that data and leverage it to help organizations of all types and sizes be ready for the future, particularly in regard to the marriage of human capability and AI. Social implications In terms of human capability and AI, individuals, teams, organizations, customers and other stakeholders will all benefit. The investment of time and other resources is minimal, but must include C-suite buy in. Originality/value Much exists on the softer aspects of the marriage of human capability and AI and other workplace advancements. What has been lacking – until now – is a 1) practical, 2) validated and 3) scalable behavioral insights tech form that quantifiably informs how people and AI will work in the future, especially side by side.

Perceived workplace gender-bias and psychological impact

2019 ◽  
Vol 43 (3/4) ◽  
pp. 339-353 ◽  
Author(s):  
Siham Lekchiri ◽  
Cindy Crowder ◽  
Anna Schnerre ◽  
Barbara A.W. Eversole
Keyword(s):  
Gender Bias ◽  
Critical Incident ◽  
Psychological Impact ◽  
Working Women ◽  
Content Type ◽  
Treatment Bias ◽  
Male Dominated ◽  
The Impact ◽  
Organizational Mechanisms ◽  
Practical Implications

Purpose The purpose of this paper is to explore the experiences of working women in a male-dominated country (Morocco) and unveil the unique challenges and everyday gender-bias they face, the psychological impact of the perceived gender-bias and, finally, identify a variety of coping strategies or combatting mechanisms affecting their motivation and retention in the workplace. Design/methodology/approach Empirical evidence was obtained using a qualitative research method. The Critical Incident Technique (CIT) was used to collect incidents recalled by women in the select institution reflecting their perceptions of their managers’ ineffective behaviors towards them and the impact of these behaviors. The critical incidents were inductively coded, and behavioral statements were derived from the coded data. Findings The qualitative data analysis led them to structure the data according to two theme clusters: The perceived gender-bias behaviors (Covert and evident personal and organizational behaviors) and Psychological impacts resulting from the perceived bias. These behavioral practices included abusive behaviors, unfair treatment, bias and lack of recognition. The psychological impact elements involved decreased productivity, depression, anxiety and low self-esteem. Practical implications Understanding these experiences can facilitate the identification of strategies geared towards the retention of women in the workforce, and Moroccan organizations can develop and implement strategies and policies that are geared towards eliminating gender-bias in the workplace and to retaining and motivating women who remain ambitious to work in male-dominated environments and cultures. Originality/value This paper provides evidence that sufficient organizational mechanisms to support women in male-dominated environments are still unavailable, leaving them to find the proper coping mechanisms to persevere and resist.

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