Search results

1 – 10 of over 2000
Article
Publication date: 31 January 2023

Husanboy Ahunov

This paper aims to systematically review the field of non-financial reporting (NFR) in hybrid organizations, focusing on state-owned enterprises, third-sector organizations and…

Abstract

Purpose

This paper aims to systematically review the field of non-financial reporting (NFR) in hybrid organizations, focusing on state-owned enterprises, third-sector organizations and public–private partnerships. This is a timely attempt to identify the state of the art in the literature and outline the future research agenda. The paper answers two research questions: RQ1. What can be learned about NFR in hybrid organizations from the existing literature? RQ2. What are the future avenues for research on the topic?

Design/methodology/approach

A systematic literature review method was applied in this paper to summarize evidence from extant literature on NFR in hybrid organizations. The Scopus and Web of Science Core Collection databases were used to locate 92 articles for the review.

Findings

Recent years have witnessed a sharp increase in the number of articles on the topic. Regarding the implications of NFR for hybrid characteristics, NFR has some potential to strengthen the influence of non-market (i.e. state, community and social) logics in hybrid organizations. However, this potential may be limited due to the effect of market logics and the tensions that arise between the multiple logics in hybrid organizations. Regarding the implications of hybrid characteristics for NFR, these characteristics can not only affect the extent, the quality, the likelihood and the institutionalization of NFR but also result in the development of new NFR frameworks. The review calls for more research on the implications of NFR for multiple institutional logics and the implications of these logics for NFR in hybrid organizations.

Originality/value

To the best of the authors’ knowledge, this is the first literature review that mobilizes insights from hybridity research to analyze NFR literature on diverse hybrid organizations.

Article
Publication date: 8 June 2022

Chinnaraj Gnanavel and Kumarasamy Vanchinathan

These implementations not only generate excessive voltage levels to enhance the quality of power but also include a detailed investigating of the various modulation methods and…

Abstract

Purpose

These implementations not only generate excessive voltage levels to enhance the quality of power but also include a detailed investigating of the various modulation methods and control schemes for multilevel inverter (MLI) topologies. Reduced harmonic modulation technology is used to produce 11-level output voltage with the production of renewable energy applications. The simulation is done in the MATLAB/Simulink for 11-level symmetric MLI and is correlated with the conventional inverter design.

Design/methodology/approach

This paper is focused on investigating the different types of asymmetric, symmetric and hybrid topologies and control methods used for the modular multilevel inverter (MMI) operation. Classical MLI configurations are affected by performance issues such as poor power quality, uneconomic structure and low efficiency.

Findings

The variations in both carrier and reference signals and their performance are analyzed for the proposed inverter topologies. The simulation result compares unipolar and bipolar pulse-width modulation (PWM) techniques with total harmonic distortion (THD) results. The solar-fed 11-level MMI is controlled using various modulation strategies, which are connected to marine emergency lighting loads. Various modulation techniques are used to control the solar-fed 11-level MMI, which is connected to marine emergency lighting loads. The entire hardware system is controlled by using SPARTAN 3A field programmable gate array (FPGA) board and the least harmonics are obtained by improving the power quality.

Originality/value

The simulation result compares unipolar and bipolar PWM techniques with THD results. Various modulation techniques are used to control the solar-fed 11-level MMI, which is connected to marine emergency lighting loads. The entire hardware system is controlled by a SPARTAN 3A field programmable gate array (FPGA) board, and the power quality is improved to achieve the lowest harmonics possible.

Details

Circuit World, vol. 49 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 15 February 2024

Chengguo Liu, Junyang Li, Zeyu Li and Xiutao Chen

The study aims to equip robots with the ability to precisely maintain interaction forces, which is crucial for tasks such as polishing in highly dynamic environments with unknown…

Abstract

Purpose

The study aims to equip robots with the ability to precisely maintain interaction forces, which is crucial for tasks such as polishing in highly dynamic environments with unknown and varying stiffness and geometry, including those found in airplane wings or thin, soft materials. The purpose of this study is to develop a novel adaptive force-tracking admittance control scheme aimed at achieving a faster response rate with higher tracking accuracy for robot force control.

Design/methodology/approach

In the proposed method, the traditional admittance model is improved by introducing a pre-proportional-derivative controller to accelerate parameter convergence. Subsequently, the authors design an adaptive law based on fuzzy logic systems (FLS) to compensate for uncertainties in the unknown environment. Stability conditions are established for the proposed method through Lyapunov analysis, which ensures the force tracking accuracy and the stability of the coupled system consisting of the robot and the interaction environment. Furthermore, the effectiveness and robustness of the proposed control algorithm are demonstrated by simulation and experiment.

Findings

A variety of unstructured simulations and experimental scenarios are designed to validate the effectiveness of the proposed algorithm in force control. The outcomes demonstrate that this control strategy excels in providing fast response, precise tracking accuracy and robust performance.

Practical implications

In real-world applications spanning industrial, service and medical fields where accurate force control by robots is essential, the proposed method stands out as both practical and straightforward, delivering consistently satisfactory performance across various scenarios.

Originality/value

This research introduces a novel adaptive force-tracking admittance controller based on FLS and validated through both simulations and experiments. The proposed controller demonstrates exceptional performance in force control within environments characterized by unknown and varying.

Details

Industrial Robot: the international journal of robotics research and application, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 13 February 2024

Yi Xia, Yonglong Li, Hongbin Zang, Yanpian Mao, Haoran Wang and Jialong Li

A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the…

Abstract

Purpose

A switching depth controller based on a variable buoyancy system (VBS) is proposed to improve the performance of small autonomous underwater vehicles (AUVs). First, the requirements of VBS for small AUVs are analyzed. Second, a modular VBS with high extensibility and easy integration is proposed based on the concepts of generality and interchangeability. Subsequently, a depth-switching controller is proposed based on the modular VBS, which combines the best features of the linear active disturbance rejection controller and the nonlinear active disturbance rejection controller.

Design/methodology/approach

The controller design and endurance of tiny AUVs are challenging because of their low environmental adaptation, limited energy resources and nonlinear dynamics. Traditional and single linear controllers cannot solve these problems efficiently. Although the VBS can improve the endurance of AUVs, the current VBS is not extensible for small AUVs in terms of the differences in individuals and operating environments.

Findings

The switching controller’s performance was examined using simulation with water flow and external disturbances, and the controller’s performance was compared in pool experiments. The results show that switching controllers have greater effectiveness, disturbance rejection capability and robustness even in the face of various disturbances.

Practical implications

A high degree of standardization and integration of VBS significantly enhances the performance of small AUVs. This will help expand the market for small AUV applications.

Originality/value

This solution improves the extensibility of the VBS, making it easier to integrate into different models of small AUVs. The device enhances the endurance and maneuverability of the small AUVs by adjusting buoyancy and center of gravity for low-power hovering and pitch angle control.

Details

Industrial Robot: the international journal of robotics research and application, vol. 51 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 18 September 2023

Yali Han, Shunyu Liu, Jiachen Chang, Han Sun, Shenyan Li, Haitao Gao and Zhuangzhuang Jin

This paper aims to propose a novel system design and control algorithm of lower limb exoskeleton, which provides walking assistance and load sharing for the wearer.

Abstract

Purpose

This paper aims to propose a novel system design and control algorithm of lower limb exoskeleton, which provides walking assistance and load sharing for the wearer.

Design/methodology/approach

In this paper, the valve-controlled asymmetrical hydraulic cylinder is selected for driving the hip and knee joint of exoskeleton. Pressure shoe is developed that purpose on detecting changes in plantar force, and a fuzzy recognition algorithm using plantar pressure is proposed. Dynamic model of the exoskeleton is established, and the sliding mode control is developed to implement the position tracking of exoskeleton. A series of prototype experiments including benchtop test, full assistance, partial assistance and loaded walking experiments are set up to verify the tracking performance and power-assisted effect of the proposed exoskeleton.

Findings

The control performance of PID control and sliding mode control are compared. The experimental data shows the tracking trajectories and tracking errors of sliding mode control and demonstrate its good robustness to nonlinearities. sEMG of the gastrocnemius muscle tends to be significantly weakened during assisted walking.

Originality/value

In this paper, a structure that the knee joint and hip joint driven by the valve-controlled asymmetrical cylinder is used to provide walking assistance for the wearer. The sliding mode control is proposed to deal with the nonlinearities during joint rotation and fluids. It shows great robustness and frequency adaptability through experiments under different motion frequencies and assistance modes. The design and control method of exoskeleton is a good attempt, which takes positive impacts on the productivity or quality of the life of wearers.

Details

Industrial Robot: the international journal of robotics research and application, vol. 51 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Open Access
Article
Publication date: 29 September 2023

Michelle Carr and Stefan Jooss

COVID-19 has forced Big 4 firms to challenge existing management control arrangements and adapt their ways of working. Yet, we know little about how management control might be…

3906

Abstract

Purpose

COVID-19 has forced Big 4 firms to challenge existing management control arrangements and adapt their ways of working. Yet, we know little about how management control might be enacted in the future of the sustainable workplace. The objective of the study is to examine the patterns of management control change in the Big 4 accounting firms during the COVID-19 pandemic.

Design/methodology/approach

Adopting an exploratory qualitative research design, the authors draw on 42 interviews with directors and associates in the Big 4 professional services firms.

Findings

The findings reveal two pathways of management control change including alignment and displacement. The authors found that relatively minor adaptions to action and result controls were relied upon to respond to substantial cultural and personnel control changes.

Originality/value

The contributions are threefold: the authors take a temporal perspective to (1) unpack the changes to management control arrangements; (2) theorise the findings by developing a three-dimensional taxonomy of change pathways encompassing pace, scope and longevity of management control change and (3) contextualise management control arrangements in a hybrid work setting.

Highlights

  1. COVID-19 has forced Big 4 firms to challenge existing management control arrangements.

  2. Literature has focused on traditional, onsite work settings and largely ignored change pathways.

  3. The authors take a temporal perspective to unpack changes to management control arrangements.

  4. Big 4 firms adapted to hybrid work with substantial changes to personnel and cultural controls.

  5. The authors theorise the findings by developing a three-dimensional taxonomy of change pathways.

COVID-19 has forced Big 4 firms to challenge existing management control arrangements.

Literature has focused on traditional, onsite work settings and largely ignored change pathways.

The authors take a temporal perspective to unpack changes to management control arrangements.

Big 4 firms adapted to hybrid work with substantial changes to personnel and cultural controls.

The authors theorise the findings by developing a three-dimensional taxonomy of change pathways.

Details

Accounting, Auditing & Accountability Journal, vol. 36 no. 9
Type: Research Article
ISSN: 0951-3574

Keywords

Article
Publication date: 15 September 2023

Navid Mohammadi, Morteza Tayefi and Man Zhu

Dual-thrust hybrid unmanned aerial vehicle (UAV) technology offers a highly robust and efficient system that incorporates the take-off and landing capabilities of rotary-wing…

Abstract

Purpose

Dual-thrust hybrid unmanned aerial vehicle (UAV) technology offers a highly robust and efficient system that incorporates the take-off and landing capabilities of rotary-wing aircraft with the endurance capacities of fixed-wing aircraft. The purpose of this study is to model and control a hybrid UAV in three distinct flight modes: rotary-wing, fixed-wing and over-actuated model.

Design/methodology/approach

Model predictive control (MPC) along with linear models are applied to design controllers for the rotary-wing or vertical take-off and transition to the fixed-wing flight. The MPC algorithm is implemented with two approaches, first in its usual form and then in a new form with the help of tracking error variables as state variables.

Findings

Because the tracking error variables are more compatible with the cost function used in MPC, the results improve significantly. This is especially important for a safe and stable transition from rotary-wing to fixed-wing flight, which should be done quickly. The authors also propose a control allocation strategy with MPC algorithm to exploit the thrust and control inputs of both rotary-wing and fixed-wing systems for the transition phase. As the control system is over-actuated, the proposed algorithm distributes the control signal among the actuators better than the MPC alone. The numerical results show that the flight trajectory is also improved.

Originality/value

The research background is reviewed in the introduction section. The other sections are originally developed in this paper to the best of the authors’ knowledge.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Open Access
Article
Publication date: 20 March 2023

Malin Härström

This paper examines the qualities of situations wherein hybrid professionals in knowledge-intensive public organizations (KIPOs) vary in their displays of conflicting…

Abstract

Purpose

This paper examines the qualities of situations wherein hybrid professionals in knowledge-intensive public organizations (KIPOs) vary in their displays of conflicting institutional logics. Specifically, it examines the situations when individual researchers vary in their displays of a traditionalist academic- and an academic performer logic.

Design/methodology/approach

Analysis is grounded in an institutional logics perspective and founded on qualitative interviews with university researchers recurrently exposed to performance measurement and management.

Findings

The findings show that individual researchers display a traditionalist academic- and an academic performer logic in situations of lower or higher “perceived control exposure” (i.e. perceptions of (not) being exposed to “what the performance measurement system wants to/can ‘see’”). In more detail, that a traditionalist academic logic is displayed more in situations of lower “perceived control exposure” whereas an academic performer logic is displayed comparatively more in situations of higher “perceived control exposure”.

Originality/value

These findings add insight into when there is room for resistance to pressures to perform in accordance with increasing performance measurement and when researchers more so tend to conform. While previous research has mostly studied such matters by emphasizing variation between researchers, this study points out the importance of situations of lower or higher “perceived control exposure”. Such insight is arguably also more broadly valuable since it adds to our understanding about hybridity of professionals in KIPOs and how to design and use performance measurement systems in relation to them.

Details

Journal of Public Budgeting, Accounting & Financial Management, vol. 35 no. 6
Type: Research Article
ISSN: 1096-3367

Keywords

Open Access
Article
Publication date: 25 December 2023

Anna Trubetskaya, Alan Ryan, Daryl John Powell and Connor Moore

Output from the Irish Dairy Industry has grown rapidly since the abolition of quotas in 2015, with processors investing heavily in capacity expansion to deal with the extra milk…

Abstract

Purpose

Output from the Irish Dairy Industry has grown rapidly since the abolition of quotas in 2015, with processors investing heavily in capacity expansion to deal with the extra milk volumes. Further capacity gains may be achieved by extending the processing season into the winter, a key enabler for which being the reduction of duration of the winter maintenance overhaul period. This paper aims to investigate if Lean Six Sigma tools and techniques can be used to enhance operational maintenance performance, thereby releasing additional processing capacity.

Design/methodology/approach

Combining the Six-Sigma Define, Measure, Analyse, Improve, Control (DMAIC) methodology and the structured approach of Turnaround Maintenance (TAM) widely used in process industries creates a novel hybrid model that promises substantial improvement in maintenance overhaul execution. This paper presents a case study applying the DMAIC/TAM model to Ireland’s largest dairy processing site to optimise the annual maintenance shutdown. The objective was to deliver a 30% reduction in the duration of the overhaul, enabling an extension of the processing season.

Findings

Application of the DMAIC/TAM hybrid resulted in process enhancements, employee engagement and a clear roadmap for the operations team. Project goals were delivered, and original objectives exceeded, resulting in €8.9m additional value to the business and a reduction of 36% in the duration of the overhaul.

Practical implications

The results demonstrate that the model provides a structure that promotes systematic working and a continuous improvement focus that can have substantial benefits for wider industry. Opportunities for further model refinement were identified and will enhance performance in subsequent overhauls.

Originality/value

To the best of the authors’ knowledge, this is the first time that the structure and tools of DMAIC and TAM have been combined into a hybrid methodology and applied in an Irish industrial setting.

Details

International Journal of Lean Six Sigma, vol. 15 no. 8
Type: Research Article
ISSN: 2040-4166

Keywords

Article
Publication date: 19 March 2024

Naseer Khan, Zeeshan Gohar, Faisal Khan and Faisal Mehmood

This study aims to offer a hybrid stand-alone system for electric vehicle (EV) charging stations (CS), an emerging power scheme due to the availability of renewable and…

Abstract

Purpose

This study aims to offer a hybrid stand-alone system for electric vehicle (EV) charging stations (CS), an emerging power scheme due to the availability of renewable and environment-friendly energy sources. This paper presents the analysis of a photovoltaic (PV) with an adaptive neuro-fuzzy inference system (ANFIS) algorithm, solid oxide fuel cell (SOFC) and a battery storage scheme incorporated for EV CS in a stand-alone mode. In previous studies, either the hydrogen fuel of SOFC or the irradiance is controlled using artificial neural network. These parameters are not controlled simultaneously using an ANFIS-based approach. The ANFIS-based stand-alone hybrid system controlling both the fuel flow of SOFC and the irradiance of PV is discussed in this paper.

Design/methodology/approach

The ANFIS algorithm provides an efficient estimation of maximum power (MP) to the nonlinear voltage–current characteristics of a PV, integrated with a direct current–direct current (DC–DC) converter to boost output voltage up to 400 V. The issue of fuel starvation in SOFC due to load transients is also mitigated using an ANFIS-based fuel flow regulator, which robustly provides fuel, i.e. hydrogen per necessity. Furthermore, to ensure uninterrupted power to the CS, PV is integrated with a SOFC array, and a battery storage bank is used as a backup in the current scenario. A power management system efficiently shares power among the aforesaid sources.

Findings

A comprehensive simulation test bed for a stand-alone power system (PV cells and SOFC) is developed in MATLAB/Simulink. The adaptability and robustness of the proposed control paradigm are investigated through simulation results in a stand-alone hybrid power system test bed.

Originality/value

The simulation results confirm the effectiveness of the ANFIS algorithm in a stand-alone hybrid power system scheme.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

1 – 10 of over 2000