Merwan Engineer, Ian King and Nilanjana Roy
The human development index (HDI) and gender‐related development index (GDI) have become accepted as leading measures for ranking human well being in different countries. The…
Abstract
Purpose
The human development index (HDI) and gender‐related development index (GDI) have become accepted as leading measures for ranking human well being in different countries. The purpose of this paper is to identify the planning policies that improve these indices and to also suggest modifications to the indices that yield more sensible policies.Design/methodology/approach – This paper solves the first‐best welfare problem in which the planner maximizes a development index subject to resource constraints.Findings – Planning strategies that maximize the HDI tend towards minimizing consumption and maximizing expenditures on education and health. Interestingly, such strategies also tend towards equitable allocations, even though inequality aversion is not modelled in the HDI. The paper shows that the GDI generates optimal plans with similar properties, and determine when the GDI and HDI generate consistent optimal plans. A problematic feature of the optimal plans is that the income component in the HDI (or GDI) does not play its intended role of securing resources for a decent standard of living. Rather, it acts to distort the allocation between health and education expenditure. The paper argues that it is better to drop income from the index. Alternatively, the paper considers net income, income net of education and health expenditures, as indicating capabilities not already reflected in the index. Finally, it compares how the modified indices and the HDI rank countries.Originality/value – The paper is believed to be the first to integrate development indices into national development planning.
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It is very complicated to keep the business processes under control since the business processes change rapidly and thus flexibility is an important attribute which businesses…
Abstract
Purpose
It is very complicated to keep the business processes under control since the business processes change rapidly and thus flexibility is an important attribute which businesses should possess in order to respond to rapid changes in the business environment. The purpose of this paper is to divide the companies' customers into different priority groups to be served according to their payment history and feedback in order to increase the companies' performance and profit and save the time of customers within high priority class which may lead to increase their satisfaction.
Design/methodology/approach
The paper proposes a requirements engineering‐based approach for business process modelling to assist businesses maintain their performance in such an environment. The paper proposes a new numerical model to improve customer satisfaction in relation to delivery or service waiting time according to their priority class, particularly customers in the high priority class. A call centre at the selected telecommunication company is used as a case study to validate the proposed numerical model.
Findings
The customers' satisfaction in the area of the time to be served according to their priority group classes can be improved using the proposed model.
Research limitations/implications
The paper has some limitations as the paper only tested the numerical model on one real business organisation and one business process service.
Originality/value
To date, no research has been conducted in the area of separating customers into different priority groups to provide services according to their required delivery time, payment history and feedback which will increase the company's performance and profit and provide prompt service to customers in the high priority class which in turn, will increase their satisfaction.
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Chandra B. Khatri and Satish C. Sharma
The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal…
Abstract
Purpose
The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing.
Design/methodology/approach
In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique.
Findings
The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing.
Originality/value
The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.
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Krishnkant Sahu and Satish C. Sharma
This study aims to deal with the performance of symmetric/asymmetric slot entry hybrid journal bearing system considering the effect of three dimensional irregularities in the…
Abstract
Purpose
This study aims to deal with the performance of symmetric/asymmetric slot entry hybrid journal bearing system considering the effect of three dimensional irregularities in the analysis.
Design/methodology/approach
The asperity profile of three-dimensional irregularities has been modeled in both circumferential and axial directions. To compute the bearing performance characteristics parameter, finite element formulation of governing Reynolds equation has been derived using Galerkin’s technique.
Findings
Based on the numerically simulated results, it has been observed that the three-dimensional irregularities enhance the value of minimum fluid film thickness (h̄min), lubricant flow (Q̄) and fluid film damping coefficients (C̄11,C̄22) approximately by order of magnitude of 24-26, 43-51 and 18-66 per cent, respectively, for the case of asymmetric slot entry configuration. Whereas, the values of fluid film stiffness coefficients (S̄11,S̄22) and threshold speed (ω̄th) reduces approximately by order of 1-6 and 0-3 per cent, respectively, for the case of symmetric slot entry configuration.
Originality/value
The present paper describes that the influence of three-dimensional irregularities on bearing surface on the performance of slot entry hybrid journal bearing is original in literature gaps. The numerically simulated results presented in this study are expected to be quite useful to the bearing designers.
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IT has been stated above that the rate of heat transfer is closely proportional to the temperature difference between the plate and the free air stream, and over the laminar…
Abstract
IT has been stated above that the rate of heat transfer is closely proportional to the temperature difference between the plate and the free air stream, and over the laminar portion it will also be proportional to the conductivity of the air. It remains to consider to what extent the actual temperature of the air in the boundary layer will influence the rate of heat transfer. The conductivity of air increases with temperature by reason of the increased molecular velocities, and we might expect, therefore, that the hotter the surface the greater will be the rate of heat transfer per unit of temperature difference above that of the air. This is, in fact, found to be the case.
Rajiv Tiwari and Rahul Chandran
In optimum designs of deep-groove ball bearings (DDGBs), an extended service life is one of the vital criteria. The life of a bearing depends on several factors. The purpose of…
Abstract
Purpose
In optimum designs of deep-groove ball bearings (DDGBs), an extended service life is one of the vital criteria. The life of a bearing depends on several factors. The purpose of this paper is to sequentially optimize three prime objectives for DDGB, i.e. the dynamic capacity (Cd), the maximum bearing temperature (Tmax) and the elasto-hydrodynamic minimum film thickness (Hmin).
Design/methodology/approach
For solving constrained non-linear optimization formulations with multitude of objectives, an optimal design methodology has been put forth with the help of artificial bee colony algorithms. A study on the constraint violation has been carried out. By the Monte Carlo simulation method, a sensitivity investigation of diverse design variables has been done to examine variations in three objective functions and violation of constraints.
Findings
Excellent improvement in the dynamic capacity (Cd), the maximum bearing temperature (Tmax) and the elasto-hydrodynamic minimum film thickness (Hmin) have been found in optimized bearing designs.
Originality/value
Ball bearing design has been done based on multi-discipline objectives that are based on strength, tribology and thermal consideration. This type of design is essential in practical scenario where these physical phenomena will be present simultaneously.
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The following is a complete list of World's Records as officially homologated by the Fédération Aéronautique Internationale up to December 31, 1929
The main objective of this study is to develop a numerical model based on Isogeometric Analysis to study the dynamic behavior of multi-directional functionally graded plates with…
Abstract
Purpose
The main objective of this study is to develop a numerical model based on Isogeometric Analysis to study the dynamic behavior of multi-directional functionally graded plates with variable thickness.
Design/methodology/approach
A numerical study was conducted on the dynamic behavior of multi-directional functionally graded plates. Rectangular and circular plates with variable thickness are taken into investigation. The third-order shear deformation plate theory of Reddy is used to describe the displacement field, while the equation of motion is developed based on the Hamilton's principle. Isogeometric Analysis approach is employed as a discretization tool to develop the system equation, where NURBS basis functions are used. The famous Newmark method is used to solve time-dependent problems.
Findings
The results obtained from this study indicated that the thickness gradation has a more considerable effect than in-plane variation of materials in MFGM plates. Additionally, the influence of the damping factor is observed to affect the vibration amplitude of the plate. The results obtained from this study could be used for future investigations, where the viscous elasticity and other dynamic factors are considered.
Originality/value
Although there have been a number of studies in the literature devoted to analyzing the linear static bending and free vibration of FGM and MFGM plates with variable thickness, the study on dynamic response of FGM and MFGM plate is still limited. Therefore, this study is dedicated to the investigation of the dynamic behavior of multi-directional functionally graded plates.
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H.C. Garg and Vijay Kumar
The changing technological scenario necessitated hybrid journal bearings to operate under severe conditions of heavy load and high speed resulting into temperature rise of the…
Abstract
Purpose
The changing technological scenario necessitated hybrid journal bearings to operate under severe conditions of heavy load and high speed resulting into temperature rise of the lubricant fluid-film and bearing surface. To predict the performance of a bearing realistically, theoretical model must consider the combined influence of the rise of temperature and non-Newtonian behavior of the lubricant. The aim of the present paper is to study the effect of viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on performance of constant flow valve compensated multiple hole-entry hybrid journal bearings.
Design/methodology/approach
Finite element method has been used to solve Reynolds equation along with restrictor flow equation, 3D energy equation and 3D conduction equation using suitable iterative technique. The non-Newtonian lubricant has been assumed to follow cubic shear stress law.
Findings
The thermohydrostatic rheological performances of symmetric and asymmetric hole-entry hybrid journal bearing configurations are studied. The computed results illustrate that variation of viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of hole-entry hybrid journal bearing system quite significantly.
Originality/value
In the present work, the influences of the viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on the performance characteristics of non-recessed hole-entry hybrid journal bearing with symmetric and asymmetric configurations compensated with constant flow valve restrictors have been investigated for generating the design data to be used by bearing designer. The design data computed in the present thesis are a contribution in field of knowledge of bearing design.
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The fatigue, thermal and wear-based bearing lives are the most important factors in the design of spherical roller bearings (SRBs). The main novelty of the present work is…
Abstract
Purpose
The fatigue, thermal and wear-based bearing lives are the most important factors in the design of spherical roller bearings (SRBs). The main novelty of the present work is consideration of thermal effects as an additional objective function. The dynamic capacity (Cd), the elasto-hydrodynamic minimum film thickness (hmin) and the maximum bearing temperature (Tmax) are related directly with overall lives of the bearing, and these constitute the multiple tasking operating requirements for the design of bearings.
Design/methodology/approach
These tasks depend upon various bearing design variables and associated constraints to help in formulating the realistic design optimization problem and in the present work these have been used to get optimal designs of SRBs in the form of Pareto-optimum fronts by using genetic algorithms.
Findings
The optimized lives show higher values as compared to the standard lives and better design choices as compared to that are available in the literature. The robustness of obtained designs are shown by conducting the sensitivity analysis of optimized operating requirements by perturbing optimum bearing variables.
Research limitations/implications
The robustness of the design could be improved by optimizing tolerances of design variables based on desired variation in multiple tasking operating requirements.
Practical implications
For the aerospace and space applications such critical design of bearings are required based on multiple tasking operating requirements. For example for higher temperature application in gearboxes, turbines and drilling equipment.
Originality/value
In critical applications, multiple tasking operating requirements are essential and often bearings put limit to the life of satellites and aircraft, and bearing design methodology proposed and implemented in the present paper addresses these issues, especially addition of thermal issue in bearing design.