Murali Dasari, A. Srinivasula Reddy and M. Vijaya Kumar
The principal intention behind the activity is to regulate the speed, current and commutation of the brushless DC (BLDC) motor. Thereby, the authors can control the torque.
Abstract
Purpose
The principal intention behind the activity is to regulate the speed, current and commutation of the brushless DC (BLDC) motor. Thereby, the authors can control the torque.
Design/methodology/approach
In order to regulate the current and speed of the motor, the Multi-resolution PID (MRPID) controller is proposed. The altered Landsman converter is utilized in this proposed suppression circuit, and the obligation cycle is acclimated to acquire the ideal DC-bus voltage dependent on the speed of the BLDC motor. The adaptive neuro-fuzzy inference system-elephant herding optimization (ANFIS-EHO) calculation mirrors the conduct of the procreant framework in families.
Findings
Brushless DC motor's dynamic properties are created, noticed and examined by MATLAB/Simulink model. The performance will be compared with existing genetic algorithms.
Originality/value
The presented approach and performance will be compared with existing genetic algorithms and optimization of different structure of BLDC motor.
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M. Vijaya Kumar, P. Sampath, S. Suresh, S.N. Omkar and Ranjan Ganguli
This paper seeks to present a feedback error learning neuro‐controller for an unstable research helicopter.
Abstract
Purpose
This paper seeks to present a feedback error learning neuro‐controller for an unstable research helicopter.
Design/methodology/approach
Three neural‐aided flight controllers are designed to satisfy the ADS‐33 handling qualities specifications in pitch, roll and yaw axes. The proposed controller scheme is based on feedback error learning strategy in which the outer loop neural controller enhances the inner loop conventional controller by compensating for unknown non‐linearity and parameter uncertainties. The basic building block of the neuro‐controller is a nonlinear auto regressive exogenous (NARX) input neural network. For each neural controller, the parameter update rule is derived using Lyapunov‐like synthesis. An offline finite time training is used to provide asymptotic stability and on‐line learning strategy is employed to handle parameter uncertainty and nonlinearity.
Findings
The theoretical results are validated using simulation studies based on a nonlinear six degree‐of‐freedom helicopter undergoing an agile maneuver. The neural controller performs well in disturbance rejection is the presence of gust and sensor noise.
Practical implications
The neuro‐control approach presented in this paper is well suited to unmanned and small‐scale helicopters.
Originality/value
The study shows that the neuro‐controller meets the requirements of ADS‐33 handling qualities specifications of a helicopter.
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Keywords
M. Vijaya Kumar, Prasad Sampath, S. Suresh, S.N. Omkar and Ranjan Ganguli
This paper aims to present the design of a stability augmentation system (SAS) in the longitudinal and lateral axes for an unstable helicopter.
Abstract
Purpose
This paper aims to present the design of a stability augmentation system (SAS) in the longitudinal and lateral axes for an unstable helicopter.
Design/methodology/approach
The feedback controller is designed using linear quadratic regulator (LQR) control with full state feedback and LQR with output feedback approaches. SAS is designed to meet the handling qualities specification known as Aeronautical Design Standard (ADS‐33E‐PRF). A helicopter having a soft inplane four‐bladed hingeless main rotor and a four‐bladed tail rotor with conventional mechanical controls is used for the simulation studies. In the simulation studies, the helicopter is trimmed at hover, low speeds and forward speeds flight conditions. The performance of the helicopter SAS schemes are assessed with respect to the requirements of ADS‐33E‐PRF.
Findings
The SAS in the longitudinal axis meets the requirement of the Level 1 handling quality specifications in hover and low speed as well as for forward speed flight conditions. The SAS in the lateral axis meets the requirement of the Level 2 handling quality specifications in both hover and low speed as well as for forward speed flight conditions. The requirements of the inter axis coupling is also met and shown for the coupled dynamics case. The SAS in lateral axis may require an additional control augmentation system or adaptive control to meet the Level 1 requirements.
Originality/value
The study shows that the design of a SAS using LQR control algorithm with full state and output feedbacks can be used to meet ADS‐33 handling quality specifications.
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Keywords
M. Balasubramanian, Thozhuvur Govindaraman Loganathan and R. Srimath
The purpose of this study is to understand the behavior of hybrid bio-composites under varied applications.
Abstract
Purpose
The purpose of this study is to understand the behavior of hybrid bio-composites under varied applications.
Design/methodology/approach
Fabrication methods and material characterization of various hybrid bio-composites are analyzed by studying the tensile, impact, flexural and hardness of the same. The natural fiber is a manufactured group of assembly of big or short bundles of fiber to produce one or more layers of flat sheets. The natural fiber-reinforced composite materials offer a wide range of properties that are suitable for many engineering-related fields like aerospace, automotive areas. The main characteristics of natural fiber composites are durability, low cost, low weight, high specific strength and equally good mechanical properties.
Findings
The tensile properties like tensile strength and tensile modulus of flax/hemp/sisal/Coir/Palmyra fiber-reinforced composites are majorly dependent on the chemical treatment and catalyst usage with fiber. The flexural properties of flax/hemp/sisal/coir/Palmyra are greatly dependent on fiber orientation and fiber length. Impact properties of flax/hemp/sisal/coir/Palmyra are depended on the fiber content, composition and orientation of various fibers.
Originality/value
This study is a review of various research work done on the natural fiber bio-composites exhibiting the factors to be considered for specific load conditions.
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Simon Lansmann, Jana Mattern, Simone Krebber and Joschka Andreas Hüllmann
Positive experiences with working from home (WFH) during the Corona pandemic (COVID-19) have motivated many employees to continue WFH after the pandemic. However, factors…
Abstract
Purpose
Positive experiences with working from home (WFH) during the Corona pandemic (COVID-19) have motivated many employees to continue WFH after the pandemic. However, factors influencing employees' WFH intentions against the backdrop of experiences during pandemic-induced enforced working from home (EWFH) are heterogeneous. This study investigates factors linked to information technology (IT) professionals' WFH intentions.
Design/methodology/approach
This mixed-methods study with 92 IT professionals examines the effects of seven predictors for IT professionals' WFH intentions. The predictors are categorized according to the trichotomy of (1) characteristics of the worker, (2) characteristics of the workspace and (3) the work context. Structural equation modeling is used to analyze the quantitative survey data. In addition, IT professionals' responses to six open questions in which they reflect on past experiences and envision future work are examined.
Findings
Quantitative results suggest that characteristics of the worker, such as segmentation preference, are influencing WFH intentions stronger than characteristics of the workspace or the work context. Furthermore, perceived productivity during EWFH and gender significantly predict WFH intentions. Contextualizing these quantitative insights, the qualitative data provides a rich yet heterogeneous list of factors why IT professionals prefer (not) to work from home.
Practical implications
Reasons influencing WFH intentions vary due to individual preferences and constraints. Therefore, a differentiated organizational approach is recommended for designing future work arrangements. In addition, the findings suggest that team contracts to formalize working patterns, e.g. to agree on the needed number of physical meetings, can be helpful levers to reduce the complexity of future work that is most likely a mix of WFH and office arrangements.
Originality/value
This study extends literature reflecting on COVID-19-induced changes, specifically the emerging debate about why employees want to continue WFH. It is crucial for researchers and practitioners to understand which factors influence IT professionals' WFH intentions and how they impact the design and implementation of future hybrid work arrangements.
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Keywords
Anupama Prashar and Vijaya Sunder M
Grounded in stakeholder theory, this study aims to examine the barriers to blockchain adoption in hospitals in developing countries. It also aimed to explore the…
Abstract
Purpose
Grounded in stakeholder theory, this study aims to examine the barriers to blockchain adoption in hospitals in developing countries. It also aimed to explore the interrelationships among these barriers and investigate how the perceptions of clinical and non-clinical professionals in the healthcare industry differ regarding these barriers.
Design/methodology/approach
The study context was hospitals in India and proceeded in three phases. First, barriers affecting blockchain application in healthcare were shortlisted using a systematic literature review. In the second phase, a multi-round Delphi study with clinical and non-clinical healthcare experts was conducted to screen and validate the barriers identified in the first phase. Finally, the barriers were ranked and categorized into causal and effect groups using the Grey-DEMATEL technique in the last phase of the study.
Findings
The findings reveal variance in the viewpoints of clinical and non-clinical professionals regarding influential barriers. Overall, the most significant causal barriers were a shortage of IT skills and a lack of standards for patient data management standards in Indian hospitals. Additionally, the study identified the lack of a well-defined strategy for blockchain infrastructure deployment and limited support from hospital management as effect barriers.
Originality/value
To the best of the authors’ knowledge, this is the first attempt to use the integrated Delphi-DEMATEL approach to explore blockchain adoption barriers in hospitals from the expert’s point of view.
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Vijaya Prasad B., Arumairaj Paul Daniel, Anand N. and Siva Kumar Yadav
Concrete is a building material widely used for the infrastructural development. Cement is the binding material used for the development of concrete. It is the primary cause of CO2…
Abstract
Purpose
Concrete is a building material widely used for the infrastructural development. Cement is the binding material used for the development of concrete. It is the primary cause of CO2 emission globally. The purpose of this study is to develop sustainable concrete material to satisfy the present need of construction sector. Geopolymer concrete (GPC) is a sustainable concrete developed without the use of cement. Therefore, investigations are being conducted to replace the cement by 100% with high calcium fly ash (FA) as binding material.
Design/methodology/approach
High calcium FA is used as cementitious binder, sodium hydroxide (NaOH) and sodium silicates (Na2SiO3) are used as alkaline liquids for developing the GPC. Mix proportions with different NaOH molarities of 4, 6, 8 and 10 M are considered to attain the appropriate mix. The method of curing adopted is ambient and oven curing. Workability, compressive strength and microstructure characteristics of GPC are analysed and presented.
Findings
An increase of NaOH in the mix decreases the workability. Compressive strength of 29 MPa is obtained for Mix-I with 8 M under ambient curing. A polynomial relationship is obtained to predict the compressive strength of GPC. Scanning electron microscope analysis is used to confirm the geo-polymerisation process in the microstructure of concrete.
Originality/value
This research work focuses on finding some alternative cementitious material for concrete that can replace ordinary portland cement (OPC) to overcome the CO2 emission owing to the utilisation of cement in the construction industry. An attempt has been made to use the waste material (high calcium FA) from thermal power plant for the production of GPC. GPC concrete is the novel building material and alternative to conventional concrete. It is the ecofriendly product contributing towards the improvement of the circular economy in the construction industry. There are several factors that affect the property of GPC such as type of binder material, molarity of activator solution and curing condition. The novelty of this work lies in the approach of using locally available high calcium FA along with manufactured sand for the development of GPC. As this approach is rarely investigated, to prove the attainment of compressive strength of GPC with high calcium FA, an attempt has been made during the present investigation. Other influencing parameter which affects the strength gain has also been analysed in this paper.
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Vijaya Sunder M., L.S. Ganesh and Rahul R. Marathe
The purpose of this paper is to review the existing literature on Lean Six Sigma (LSS) for services, construct a morphological analysis (MA) framework and identify research gaps…
Abstract
Purpose
The purpose of this paper is to review the existing literature on Lean Six Sigma (LSS) for services, construct a morphological analysis (MA) framework and identify research gaps to point to future research possibilities and priorities.
Design/methodology/approach
The MA framework is based on literature review of 175 papers published from 2003 to 2015, across 67 journals recognised by Scopus or ABS Academic Journal Quality Guide 2015. A three-phased methodology is used by the authors, with Phase1 featuring a five-stage systematic review protocol to identify relevant journal papers for review; Phase2 presenting a framework for classifying the reviewed papers in terms of their fundamental, methodological, chronological and sector-wise orientations; and Phase3 constructing an MA framework on the classified papers and identifying the research gaps.
Findings
The MA framework constructed based on six dimensions, namely, organizational context of applications, desired outcomes, implementation systems, LSS tools and techniques, integration with other management philosophies and evaluation methods, involving 40 focused themes, has revealed 355 distinct research gaps as opportunities for future research.
Practical implications
This paper confirms the existence of substantial scope and points to specific topics for further research in the area of LSS for services. The findings demonstrate the gaps in academic research on the subject. In addition, the study also helps organisational leaders and practitioners to look at LSS from a holistic perspective in the services context.
Originality/value
The MA framework of the existing literature on LSS for services presents a unique, systematic effort to identify research opportunities. In addition, a five-stage systematic review protocol is proposed in this paper. This could be valuable to researchers and practitioners in enabling them to systematically review the literature on research subjects of interest to them.
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Nagisetty Jyothi and Vijaya Kumar Avula Golla
This study aims to analyze the multi-slip effects of entropy generation in steady non-linear magnetohydrodynamics thermal radiation with Williamson nanofluid flow across a porous…
Abstract
Purpose
This study aims to analyze the multi-slip effects of entropy generation in steady non-linear magnetohydrodynamics thermal radiation with Williamson nanofluid flow across a porous stretched sheet near a stagnation point. Also, the qualities of viscous dissipation, Cattaneo–Christove heat flux and Arrhenius activation energy are taken into account. Thermophoresis, Brownian motion and Joule heating are also considered.
Design/methodology/approach
The Navier–Stokes equation, the thermal energy equation and the Solutal concentration equations are the governing mathematical equations that describe the flow and heat and mass transfer phenomena for fluid domains. By using the proper similarity transformations, a set of ordinary differential equationss are retrieved from boundary flow equations. The classical Runge–Kutta fifth-order algorithm along with the shooting technique is implemented to solve the obtained first order differential equations.
Findings
The study concludes that the temperature distribution boosting for thermal radiation, magnetic field and Eckert number where as the velocity and entropy generation escalate for the Williamson parameter, diffusion parameter and Brinkman number. The skin-friction and heat and mass transfer rate increases with the fluid injection. In addition, tabulated values of friction drag and rate of heat and mass transfer for various values of constraints are provided.
Originality/value
The comparison of the present results is carried out with the published results and noted a good agreement.
Details
Keywords
Vijaya Kumar K. and Ravi Kumar Puli
The purpose of this paper is to present the influence of plastic pyrolysis oil blended with gasoline at 10 per cent with and without ethanol additive at 5 per cent in a…
Abstract
Purpose
The purpose of this paper is to present the influence of plastic pyrolysis oil blended with gasoline at 10 per cent with and without ethanol additive at 5 per cent in a three-cylinder petrol engine.
Design/methodology/approach
The engine is running at standard working processes. The result of 10PPO is compared with pure petrol and additive-added blend. The outcomes clears that, the engine performance is reduced by using plastic oil blended with petrol and NOx emission rates are increasing substantially.
Findings
To control the emission rate, ethanol is added, and corresponding performance reveals that brake thermal efficiency is 4.52 per cent increase compared to pure petrol and 7.03 per cent increase compared to without additive blend.
Originality/value
Emissions such as CO and NOx are considerably controlled with additive blend.