Syed Awais Ali Shah, Bingtuan Gao, Ajeet Kumar Bhatia, Chuande Liu and Arshad Rauf
Barge-type offshore floating wind turbine (OFWT) commonly exhibits an under-actuated phenomenon in an offshore environment, which leads to a potential vibration-damping hazard…
Abstract
Purpose
Barge-type offshore floating wind turbine (OFWT) commonly exhibits an under-actuated phenomenon in an offshore environment, which leads to a potential vibration-damping hazard. This article aims to provide a new robust output feedback anti-vibrational control scheme for the novel translational oscillator with rotational actuator (TORA) based five-degrees of freedom (5-DOF) barge-type OFWT in the presence of unwanted disturbances and modeling uncertainties.
Design/methodology/approach
In this paper, an active control technique called TORA has been used to design a 5-DOF barge-type OFWT model, where the mathematical model of the proposed system is derived by using Euler–Lagrange's equations. The robust hierarchical backstepping integral nonsingular terminal sliding mode control (HBINTSMC) with an adaptive gain is used in conjunction with extended order high gain observer (EHGO) to achieve system stabilization in the presence of unwanted disturbances and modeling uncertainties. The numerical simulations based on MATLAB/SIMULINK have been performed to demonstrate the feasibility and effectiveness of the proposed model and control law.
Findings
The numerical simulation results affirm the accuracy and efficiency of the proposed control law for the TORA based OFWT system. The results demonstrate that the proposed control law is robust against unwanted disturbances and uncertainties. The unknown states are accurately estimated by EHGO which enables the controller to exhibit improved stabilization performance.
Originality/value
A new mathematical model of the 5-DOF barge-type OFWT system based on TORA is the major contribution of this research paper. Furthermore, it provides a new adaptive anti-vibration control scheme by incorporating the EHGO for the proposed model.
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Nigar Ahmed and Syed Awais Ali Shah
In this research paper, an adaptive output-feedback robust active disturbance rejection control (RADRC) is designed for the multiple input multiple output (MIMO) quadrotor…
Abstract
Purpose
In this research paper, an adaptive output-feedback robust active disturbance rejection control (RADRC) is designed for the multiple input multiple output (MIMO) quadrotor attitude model subject to unwanted uncertainties and disturbances (UUDs).
Design/methodology/approach
In order to achieve the desired control objectives in the presence of UUDs, the low pass filter (LPF) and extended high gain observer (EHGO) methods are used for the estimation of matched and mismatched UUDs, respectively. Furthermore, for solving the chattering incurred in the standard sliding mode control (SMC), a multilayer sliding mode surface is constructed. For formulating the adaptive output-feedback RADRC algorithm, the EHGO, LPF and SMC schemes are combined using the separation principle.
Findings
The findings of this research work include the design of an adaptive output-feedback RADRC with the ability to negate the UUDs as well as estimate the unknown states of the quadrotor attitude model. In addition, the chattering problem is addressed by designing a modified SMC scheme based on the multilayer sliding mode surface obtained by utilizing the estimated state variables. This sliding mode surface is also used to obtain the adaptive criteria for the switching design gain parameters involved in the SMC. Moreover, the requirement of high design gain parameters in the EHGO is solved by combining it with the LPF.
Originality/value
Designing the flight control techniques while assuming that the state variables are available is a common practice. In addition, to obtain robustness, the SMC technique is widely used. However, in practice, the state variables might not be available due to unknown parameters and uncertainties, as well as the chattering due to SMC reduces the performances of the actuators. Hence, in this paper, an adaptive output-feedback RADRC technique is designed to solve the problems of UUDs and chattering.
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Nigar Ahmed, Ajeet kumar Bhatia and Syed Awais Ali Shah
The aim of this research is to design a robust active disturbance attenuation control (RADAC) technique combined with an extended high gain observer (EHGO) and low pass filter…
Abstract
Purpose
The aim of this research is to design a robust active disturbance attenuation control (RADAC) technique combined with an extended high gain observer (EHGO) and low pass filter (LPF).
Design/methodology/approach
For designing a RADAC technique, the sliding mode control (SMC) method is used. Since the standard method of SMC exhibits a chattering phenomenon in the controller, a multilayer sliding mode surface is designed for avoiding the chattering. In addition, to attenuate the unwanted uncertainties and disturbances (UUDs), the techniques of EHGO and LPF are deployed. Besides acting as a patch for disturbance attenuation, the EHGO design estimates the state variables. To investigate the stability and effectiveness of the designed control algorithm, the stability analysis followed by the simulation study is presented.
Findings
The major findings include the design of a chattering-free RADAC controller based on the multilayer sliding mode surface. Furthermore, a criterion of integrating the LPF scheme within the EHGO scheme is also developed to attenuate matched and mismatched UUDs.
Practical implications
In practice, the quadrotor flight is opposed by different kinds of the UUDs. And, the model of the quadrotor is a highly nonlinear underactuated model. Thus, the dynamics of the quadrotor model become more complex and uncertain due to the additional UUDs. Hence, it is necessary to design a robust disturbance attenuation technique with the ability to estimate the state variables and attenuate the UUDs and also achieve the desired control objectives.
Originality/value
Designing control methods to attenuate the disturbances while assuming that the state variables are known is a common practice. However, investigating the uncertain plants with unknown states along with the disturbances is rarely taken in consideration for the control design. Hence, this paper presents a control algorithm to address the issues of the UUDs as well as investigate a criterion to reduce the chattering incurred in the controller due to the standard SMC algorithm.
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Syed Jamal Shah, Syed Asad Ali Shah, Rizwan Ullah and Adnan Muhammad Shah
With a foundation in the conservation of resource theory, this paper aims to examine the validity of a conceptual model that explains the mechanism connecting perceived threat of…
Abstract
Purpose
With a foundation in the conservation of resource theory, this paper aims to examine the validity of a conceptual model that explains the mechanism connecting perceived threat of terrorism to production deviance. The link between perceived threat of terrorism and production deviance was examined via emotional exhaustion. Notably, the study evaluated whether the relationship between perceived threat of terrorism and production deviance is mediated by emotional exhaustion and moderated by levels of emotional intelligence.
Design/methodology/approach
The study is cross-sectional in nature and data were collected from 432 pharmaceutical sales representatives who operate outdoors in the high-risk region. Two-step approach consisting confirmatory factor analysis and structural equation modeling was used for analysis. To examine conditional direct and indirect effects, the authors used model 8 in PROCESS.
Findings
Results were consistent with prediction made from the conceptual model in that emotional exhaustion partially mediated the relationship between perceived threat of terrorism and production deviance. This was particularly the case when emotional intelligence was low, but not when high. Likewise, perceived threat of terrorism exerted a direct effect on production deviance when emotional intelligence was low, but not when high.
Originality/value
The study is the first to examine the relationship between perceived threat of terrorism and production deviance. Moreover, no study to date has examined the mediating role of emotional exhaustion between perceived threat of terrorism and production deviance. Finally, up till now, it is unknown that emotional intelligence moderates the relationship of perceived threat of terrorism with emotional exhaustion and production deviance.
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Mudassar Ali, Li Zhang, Syed Jamal Shah, Salim Khan and Adnan Muhammad Shah
This paper aims to examine the impact of humble leadership on project success. The mediating effects of psychological empowerment and innovative work behavior on the relationship…
Abstract
Purpose
This paper aims to examine the impact of humble leadership on project success. The mediating effects of psychological empowerment and innovative work behavior on the relationship between humble leadership and project success are tested.
Design/methodology/approach
Data were collected from 337 individuals employed in the civil construction sector of Pakistan.
Findings
The results showed that humble leadership is positively related to project success. Furthermore, psychological empowerment and innovative work behavior partially mediate the relationship between humble leadership and project success.
Originality/value
Drawing on conservation of resource theory, this study found that how humble leadership is important for project success and thus extends the utility of the concept of humble leadership to the project literature.
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Muhammad Imran Malik, Faisal Nawaz Mir, Saddam Hussain, Shabir Hyder, Asim Anwar, Zia Ullah Khan, Noman Nawab, Syed Farjad Ali Shah and Muhammad Waseem
This paper aims to examine the mediating role of environmental concern in the relationship of green purchase awareness and purchasing behavior of fast food consumers keeping in…
Abstract
Purpose
This paper aims to examine the mediating role of environmental concern in the relationship of green purchase awareness and purchasing behavior of fast food consumers keeping in view the theory of planned behavior.
Design/methodology/approach
A quantitative, cross-sectional design is used by collecting primary responses through a validated questionnaire. In all, 1,008 male and female buyers of fast food were sampled. Structural equation modeling is applied.
Findings
The results revealed that green purchase awareness has a positive relationship with green purchase behavior, and environmental concern has no mediation in the relationship. Upon having awareness, the respondents adopted green or pro-environmental behavior, but at the same time, they were found having least concern for the protection of environment.
Research limitations/implications
This is a cross-sectional study with questionnaire. Multiple sources of data collection results in weakening self-reporting bias.
Practical implications
Implications count toward individuals, enterprises and society at general.
Originality/value
The study highlights the issue of not having concern for the protection of the environment even after having green purchase awareness. This is the first time the environmental concern is examined as a mediator in the selected relationship. The contradictory results of having no environmental concern differentiate this study from others.
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Muhammad Anwar, Syed Zulfiqar Ali Shah and Sher Zaman Khan
This paper aims to examine the role of owners/managers’ big five personality traits: conscientiousness, openness, extroversion, neuroticism and agreeableness on SMEs…
Abstract
Purpose
This paper aims to examine the role of owners/managers’ big five personality traits: conscientiousness, openness, extroversion, neuroticism and agreeableness on SMEs internationalization.
Design/methodology/approach
The research design is a quantitative approach. Structured questionnaires were used to collect data from 303 owners and managers of Pakistani SMEs. The hypotheses were tested through structural equation modeling using AMOS.
Findings
The findings reveal that conscientiousness has an insignificant influence on the degree of internationalization while neuroticism has a significant negative influence on internationalization. Extroversion, openness and agreeableness have a significant positive influence on internationalization. The findings disclose that owners and managers with extrovert, openness and agreeable personality are more likely to enter into international markets, while managers and owners with conscientiousness and neuroticism personality do not endorse entry into foreign markets.
Practical implications
The results suggest that not all the personality traits facilitate internationalization process. Hence, firms that intend to enter international markers can benefit from hiring extrovert, open and agreeable personalities as managers to achieve their objectives. While managers with conscientiousness and neuroticism can be gainfully employed in other departments, they should be kept away from the decision-making processes leading to internationalization of a firm’s operations. In addition, the insights gained from this study could facilitate CEOs and executives of large firms operating in developing and developed markets to design effective strategies to promote and get the advantages of internationalization process.
Originality/value
This research contributes to personality literature, upper echelons theory and internationalization theory by testing the model based on the empirical evidence. This research is an intersection of the international entrepreneurship literature and psychological studies that have remained relatively unattended in prior studies. After extensive search, we have concluded that no previous study has as yet explored the role of big five personality traits in SMEs internationalization, particularly in this part of the world. It is believed that lack of studies in this sphere is, to a considerable extent, impeding the pace of internationalization by SMEs in developing countries.
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Mudassar Ali, Zhang Li, Salim Khan, Syed Jamal Shah and Rizwan Ullah
This paper aims to examine the impact of humble leadership on project success. The authors propose that such an effect is mediated by team-building, and top management support…
Abstract
Purpose
This paper aims to examine the impact of humble leadership on project success. The authors propose that such an effect is mediated by team-building, and top management support moderates the direct relationship (humble leadership and project success) as well as an indirect relationship through team-building.
Design/methodology/approach
Data were collected from 337 individuals employed in the information technology sector of Pakistan. A two-step approach consisting confirmatory factor analysis and structural equation modeling was used for analysis. To examine conditional direct and indirect effects, the authors utilized model 8 in PROCESS.
Findings
The results showed that humble leadership is positively related to project success. Furthermore, team-building partially mediates the relationship between humble leadership and project success. Moreover, top management support was anticipated to have a moderating effect on the direct and indirect link (via team-building) between humble leadership and project success.
Originality/value
Drawing on the conservation of resources theory, this study found that how humble leadership is vital for project success, and thus, extends the utility of the concept of humble leadership to the project literature.
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Syed Haider Khalil, Syed Mohsin Ali Shah and Syed Majid Khalil
The current study aimed to investigate how perceived human capital sustainability leadership (HCSL) affects work outcomes (i.e. work engagement and job satisfaction), specifically…
Abstract
Purpose
The current study aimed to investigate how perceived human capital sustainability leadership (HCSL) affects work outcomes (i.e. work engagement and job satisfaction), specifically through the mediating role of knowledge sharing behaviour in the hospitality industry. Building on social exchange theory and conservation of resources theory, the authors propose that knowledge sharing behaviour is an attempt to share and expand an individual's resources, which in return motivates employees during work. Furthermore, through the mediating effect of knowledge sharing behaviour, the authors attempt to provide empirical evidence for organisational actions and employees’ reciprocating actions, therefore, triggering positive contribution.
Design/methodology/approach
The authors methodologically employed structure equation modelling for the analysis which includes reflective–formative higher-order construct (HOC) (i.e. HCSL). The authors tested the hypotheses with partial least square structure equation modelling (PLS-SEM) from a sample of 382 hotel employees who were selected through purposive sampling.
Findings
This study’s findings suggest that the employee engagement and job satisfaction regresses on HCSL and knowledge sharing behaviour. The study’s analysis also suggests that the relationships between the HCSL and work outcomes are mediated by knowledge sharing behaviour.
Originality/value
This study contributes to the sustainability leadership literature by looking into the integrated model of sustainable leadership from its four dimensions (i.e. sustainability leadership, ethical leadership, mindful leadership and servant leadership) and its consequences for work outcomes. Furthermore, the authors examined how knowledge sharing behaviour, being an underlining mechanism, affects these relationships, thus having implications for academia and practitioners.
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Maqsood Ahmad and Syed Zulfiqar Ali Shah
This paper aims to show how overconfidence influences the decisions and performance of individual investors trading on the Pakistan Stock Exchange (PSX), with the mediating role…
Abstract
Purpose
This paper aims to show how overconfidence influences the decisions and performance of individual investors trading on the Pakistan Stock Exchange (PSX), with the mediating role of risk perception and moderating role of financial literacy.
Design/methodology/approach
The deductive approach was used, as the research is based on the theoretical framework of behavioural finance. A questionnaire and cross-sectional design were employed for data collection from the sample of 183 individual investors trading on the PSX. Hypotheses were tested through correlation and regression analysis. The Baron and Kenny method was used to test the mediation effect of risk perception and the moderation effect of financial literacy. The results of mediation and moderation were also authenticated through the PROCESS and structural equation modelling (SEM) technique.
Findings
The results suggest that risk perception fully mediates the relationships between the overconfidence heuristic on the one hand, and investment decisions and performance on the other. At the same time, financial literacy appears to moderate these relationships. The results suggest that overconfidence can impair the quality of investment decisions and performance, while financial literacy and risk perception can improve their quality.
Practical implications
The paper encourages investors to base decisions on their financial capability and experience levels and to avoid relying on heuristics or their sentiments when making investments. It provides awareness and understanding of heuristic biases in investment management, which could be very useful for decision makers and professionals in financial institutions, such as portfolio managers and traders in commercial banks, investment banks and mutual funds. This paper helps investors to select better investment tools and avoid repeating the expensive errors that occur due to heuristic biases. They can improve their performance by recognizing their biases and errors of judgment, to which we are all prone, resulting in better investment decisions and a more efficient market. The paper also highlights the importance on relying on professional knowledge, giving it greater weight than feelings and biases.
Originality/value
The current study is the first to focus on links between overconfidence, financial literacy, risk perception and individual investors' decisions and performance. This article enhanced the understanding of the role that heuristic-driven bias plays in the investment management, and more importantly, it went some way towards enhancing understanding of behavioural aspects and their influence on the investment decision-making and performance in an emerging market. It also adds to the literature in the area of behavioural finance specifically the role of heuristics in investment strategies; this field is in its initial stage, even in developed countries, while, in developing countries, little work has been done.