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Article
Publication date: 10 May 2011

Tomasz Pajchrowski

The purpose of the paper is to find a speed control structure with two degrees of freedom robust against drive parameters variations. Application of structure model…

Abstract

Purpose

The purpose of the paper is to find a speed control structure with two degrees of freedom robust against drive parameters variations. Application of structure model following control (MFC) and fuzzy technique in the controller of PI type creates proper non‐linear characteristics, which ensures controller robustness.

Design/methodology/approach

The use of proper structure with two degrees of freedom and non‐linear characteristic introduced by fuzzy technique ensures the robustness of the speed control system. The paper proposes a novel approach to MFC synthesis to be performed in two stages. The first stage consists in the set value of P type controller of model and the process controller simultaneously should be designing by fuzzy technique. At the second stage of the synthesis consist in tuning parameters of process fuzzy controller by the swarm of particles method (particle swarm optimization) on the basis of a defined quality index formulated in the paper. The synthesis is performed using simulation techniques and subsequently the behavior of a laboratory speed control system is validated in the experimental setup. The control algorithms of the system are performed by a microprocessor floating point DSP control system.

Findings

Use of proper structure with two degrees of freedom of the non‐linear fuzzy controller guarantees expected robustness and improves the dynamics of speed control significantly.

Research limitations/implications

The proposed structure of MFC was tested on a single machine under well‐defined conditions. Further investigations are required before any industrial applications.

Practical implications

The proposed controller synthesis and its results may be very helpful in robotic system where changing of system parameters is characteristic for many industrial robots and manipulators.

Originality/value

The paper proposes an original method of synthesis of robust system with two degrees of freedom system validated by simulation and experimental investigations.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 30 October 2019

Sreya Ghosh and Somnath Pan

This paper aims to propose a reference model based simple strategy for the design of proportional-integral-derivative (PID) controller using frequency response matching…

Abstract

Purpose

This paper aims to propose a reference model based simple strategy for the design of proportional-integral-derivative (PID) controller using frequency response matching for high-order stable, integrating and unstable processes that may have time-delay and non-minimum phase zero.

Design/methodology/approach

The reference sensitivity model is designed fulfilling stability conditions of the control system responses such as set-point response, load-disturbance response and noise response along with transient response criteria. The analytical controller thus designed is approximated to a PID controller using a simple formula based on a model-matching technique at low frequency.

Findings

PID controllers are designed for examples with varied dynamics taken from the literature, and the performances of the designed control systems are compared with some methods prevalent in the literature to show the efficacy of the proposed work. Overall, the method gives satisfactory set-point, as well as load-disturbance responses and controller-outputs in all the cases considered.

Originality/value

The method is applicable to high-order processes of various monotonic or oscillating dynamics without requiring process reduction. The PID controller designed considering a reference model with suitable criteria ensuring stability and a modified model matching technique, which provides a stable control system for all these high-order processes.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 22 August 2008

Esmaeil Atashpaz Gargari, Farzad Hashemzadeh, Ramin Rajabioun and Caro Lucas

This paper aims to describe colonial competitive algorithm (CCA), a novel socio‐politically inspired optimization strategy, and how it is used to solve real world…

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1509

Abstract

Purpose

This paper aims to describe colonial competitive algorithm (CCA), a novel socio‐politically inspired optimization strategy, and how it is used to solve real world engineering problems by applying it to the problem of designing a multivariable proportional‐integral‐derivative (PID) controller. Unlike other evolutionary optimization algorithms, CCA is inspired from a socio‐political process – the competition among imperialists and colonies. In this paper, CCA is used to tune the parameters of a multivariable PID controller for a typical distillation column process.

Design/methodology/approach

The controller design objective was to tune the PID controller parameters so that the integral of absolute errors, overshoots and undershoots be minimized. This multi‐objective optimization problem is converted to a mono‐objective one by adding up all the objective functions in which the absolute integral of errors is emphasized to be reduced as long as the overshoots and undershoots remain acceptable.

Findings

Simulation results show that the controller tuning approach, proposed in this paper, can be easily and successfully applied to the problem of designing MIMO controller for control processes. As a result not only was the controlled process able to significantly reduce the coupling effect, but also the response speed was significantly increased. Also a genetic algorithm (GA) and an analytical method are used to design the controller parameters and are compared with CCA. The results showed that CCA had a higher convergence rate than GA, reaching to a better solution.

Originality/value

The proposed PID controller tuning approach is interesting for the design of controllers for industrial and chemical processes, e.g. MIMO evaporator plant. Also the proposed evolutionary algorithm, CCA, can be used in diverse areas of optimization problems including, industrial planning, resource allocation, scheduling, decision making, pattern recognition and machine learning.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 1 no. 3
Type: Research Article
ISSN: 1756-378X

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Article
Publication date: 18 April 2016

Tiina Henttu-Aho

This paper aims to investigate the emergence of the enabling characteristics of new budgetary practices and their implications for the role of controller.

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3918

Abstract

Purpose

This paper aims to investigate the emergence of the enabling characteristics of new budgetary practices and their implications for the role of controller.

Design/methodology/approach

The longitudinal perspective of this qualitative case study is based on interviews of controllers and managers involved in budgetary work. This study monitored the four enabling characteristics of management control, namely, repair, internal transparency, global transparency and flexibility (Adler and Borys, 1996), related to the new budgeting practices in one global paper company.

Findings

The findings of the study demonstrate that the implementation of rolling forecasting was a major attempt at “repair” to remedy the incompleteness of accounting information, which made controllers experts in producing and delivering more realistic forward-looking information in the organization. The increasing internal and global transparency of new budgetary practices enabled controllers at various levels of organization to develop new competences, which helped controller network to build a holistic view of the totality of control and supply more relevant information in organization. Moreover, the inherent flexibility of the system was a major condition for improving organizational effectiveness in budgetary work. However, the study shows that the controller’s attitude towards enabling formalization is not necessarily positive if the system is not aligned with professional mindset and competence.

Originality/value

This study adds to the understanding of the complementarity between new developments of budgeting and controller role by addressing the enabling uses of management control systems, which have the potential to enhance the controller role change.

Details

Qualitative Research in Accounting & Management, vol. 13 no. 1
Type: Research Article
ISSN: 1176-6093

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Article
Publication date: 12 August 2014

Bauke Steenhuisen

The purpose of this paper is to discuss the impact of organizational change on the competence of controllers in rail infrastructure operations. Controllers are a critical…

Abstract

Purpose

The purpose of this paper is to discuss the impact of organizational change on the competence of controllers in rail infrastructure operations. Controllers are a critical link in providing rail services. They guide train traffic 7/24 in real time from within control rooms by daily responding to a multitude of disturbances. Market reforms have radically changed their work conditions by unbundling and re-bundling control rooms.

Design/methodology/approach

Ethnographically inspired research has been performed at the work stations of controllers in both unbundled and re-bundled, both Dutch and British control rooms between 2007 and 2011. The author observed how controllers deal with moderate disturbances and discusses the nature of their underlying professional capacities, what guides their decision making in discretion. Implications are discussed how organizational change affects these capacities in case of unbundling and re-bundling control rooms.

Findings

The paper shows how to gain a more explicit understanding of what controllers, as professionals, essentially think and do. An open-interactive account of professional capacity emerges, in contrast to the private-cognitive view widespread in literature. Both conceptualizations of professional capacities have radically different implications for their susceptibility to organizational change.

Originality/value

This paper reveals an urgent perspective on the impact of market reforms, through the accompanying organizational change, on professional capacity at the operational level of providing public rail services.

Details

Journal of Organizational Ethnography, vol. 3 no. 2
Type: Research Article
ISSN: 2046-6749

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Article
Publication date: 17 October 2008

Metin Özgür and Aydan Cavcar

The purpose of this paper is to develop a knowledge‐based decision support tool used for assisting en‐route air traffic controllers by generating resolutions for dual…

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1903

Abstract

Purpose

The purpose of this paper is to develop a knowledge‐based decision support tool used for assisting en‐route air traffic controllers by generating resolutions for dual aircraft conflicts after being integrated into a model‐based conflict detection and conflict resolution system.

Design/methodology/approach

Air traffic controller knowledge, which was obtained from the literature research, about solving aircraft conflicts is represented in a decision tree. Then it is written in Visual Basic programming language. With reference to several rules form the expert air traffic controller knowledge and some factors which affect controller conflict resolution process, the tool generates advisories consisting of eight kinds of separation strategies.

Findings

The paper finds that it is expected to increase the safety of air traffic system by supporting air traffic controller in conflict resolution process. Controller workload can be reduced by fast, reliable and acceptable resolution advisories of the tool.

Research limitations/implications

The accuracy of decision tree is limited with the adequacy and quality of knowledge obtained from references, several assumptions and interpretation. Because of the unavailability of a model‐based conflict detection and resolution tool, the tool could not be evaluated in simulations.

Originality/value

After being integrated into a model‐based decision support tool, it can reduce the deficiencies of the model‐based tool such as low degree of resolution acceptance by controllers and low‐resolution speed by providing expert air traffic controller knowledge to the tool.

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 24 May 2013

Yuriy Panteliyovych Kondratenko, Leonid Pavlovych Klymenko and Eyad Yasin Mustafa Al Zu'bi

The purpose of this paper is to propose a general method to simplify the structure of fuzzy controllers' rule base using integrated methodology for reducing the number of…

Abstract

Purpose

The purpose of this paper is to propose a general method to simplify the structure of fuzzy controllers' rule base using integrated methodology for reducing the number of fuzzy rules based on modelling and simulation.

Design/methodology/approach

The paper considers the problem of developing effective methods and algorithms for optimization of fuzzy rules bases of Sugeno‐type fuzzy controllers that can be applied to control of dynamic objects, including objects with non‐stationary parameters. The proposed approach based on calculating the impact of each of the rule on the formation of control signals for different types of input signals provides optimization of a linguistic rules database by using exclusion mechanism for rules with negligible influence. The effectiveness of the proposed approach is investigated using a fuzzy PID controller for control of a non‐stationary object of second order.

Findings

In this paper, the authors argued that different aggregation models can be used for structural optimization of fuzzy controllers and not all the rules are actually required in the fuzzy controllers' rule base. Eliminating some of the rules does not necessarily lead to a significant change in the fuzzy controller's output. The proposed integrated approach based on combination of different kinds of reference input signals for fuzzy controllers modelling and simulation is able to provide guidelines to the users which rules are required and which can be eliminated. The results obtained from the case studies demonstrate that the proposed integrated approach is able to reduce the number of rules required and, at the same time, to have the desired values of quality control indices.

Research limitations/implications

In order to demonstrate the feasibility of the proposed approach, only control object of second order with PID fuzzy controller of Sugeno‐type is chosen. Future studies can advance this research by applying the proposed approach in different types of fuzzy systems.

Practical implications

The proposed integrated approach is able to simplify the structural optimization methodology and make it possible to be implemented in real processes of the fuzzy controllers' design.

Originality/value

The value of the current paper is on the proposal of an integrated approach for rule reduction to enhance the practical use of modelling and simulation in a design of fuzzy controllers.

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Article
Publication date: 5 January 2021

Ricardo Malagueño, Jacobo Gomez-Conde, Yannick de Harlez and Olaf Hoffmann

The authors examine the extent to which a controller's involvement in project functions (namely definition and scope, organization, constraints management and risk…

Abstract

Purpose

The authors examine the extent to which a controller's involvement in project functions (namely definition and scope, organization, constraints management and risk management) cascades down to project performance.

Design/methodology/approach

The authors test the study’s framework using survey data from a sample of project leaders in German and Swiss firms. Responses were analyzed using the partial least squares (PLS) technique.

Findings

The authors find that controllers contribute to project success via the previously described project functions. Further, the study reveals the crucial role of controllers in managing uncertainty and project risks.

Research limitations/implications

Although the arguments used in this research were not country specific and suggest that the findings of this study also apply to the controller professional in general, this study clearly acknowledges that further research is needed to address the effects of this role in different jurisdictions given the specific characteristics of controllers acting in German-speaking countries.

Practical implications

The authors provide insights on the role of controllers at an operational level, like project management, highlighting the need for controllers to support an effective project governance.

Originality/value

The authors add to the literature by examining the role of controllers in highly knowledge-intensive, highly pressured, task-driven, interdependent and dynamic operational settings, thus contributing to a better understanding of how controllers function at an operational level. The authors also strengthen a broader role of controllers in project management that goes beyond their historical controlling activities to include more modern functions, extending previous studies analyzing their professional identity.

Details

Journal of Applied Accounting Research, vol. 22 no. 2
Type: Research Article
ISSN: 0967-5426

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Article
Publication date: 18 October 2018

Bo Karlsson and Monika Kurkkio

The purpose of this paper is to identify and describe how calculations are used in the early phase of strategic capital investment projects (SCIPs) in the mining context…

Abstract

Purpose

The purpose of this paper is to identify and describe how calculations are used in the early phase of strategic capital investment projects (SCIPs) in the mining context and thereby create an understanding of what calculations do in these situations.

Design/methodology/approach

The authors conducted a case study based on interviews with project managers, controllers and top-level managers, as well as documents and observations.

Findings

The empirical evidence provides key insights into the different uses of calculations in the early phase of SCIPs in the mining industry. The authors found evidence that calculations in the early phase of SCIPs are used to generate ideas, support learning and discussions, evaluate decisions and act as a mediating device.

Research limitations/implications

The paper is based on a single organization, and therefore, the findings of the paper are limited to theoretical generalization.

Practical implications

The study has practical implications directed toward top management, controllers and project managers working with SCIPs. This study suggests that calculations in the early phase are used to unite and create a shared view in the early phase rather than to present rational answers to different investment decision. Calculations can also be used to direct attention toward important areas, sort out and prioritize among ideas, communicate a shared view and function as a template. Thus, calculations are essential in the early phase as they help to transform activities into actions.

Originality/value

This paper contributes to the accounting literature in which it has been emphasized that we still know little of strategic capital budgeting processes, with insights into the multiple uses of calculations in the early phase of SCIPs. We also argue that calculations act as mediating devices in the early phase of SCIPs as they provide a common frame of reference and a basis for action.

Details

Qualitative Research in Accounting & Management, vol. 15 no. 4
Type: Research Article
ISSN: 1176-6093

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Article
Publication date: 26 November 2020

Muhammad Al-Abdullah, Izzat Alsmadi, Ruwaida AlAbdullah and Bernie Farkas

The paper posits that a solution for businesses to use privacy-friendly data repositories for its customers’ data is to change from the traditional centralized repository…

Abstract

Purpose

The paper posits that a solution for businesses to use privacy-friendly data repositories for its customers’ data is to change from the traditional centralized repository to a trusted, decentralized data repository. Blockchain is a technology that provides such a data repository. However, the European Union’s General Data Protection Regulation (GDPR) assumed a centralized data repository, and it is commonly argued that blockchain technology is not usable. This paper aims to posit a framework for adopting a blockchain that follows the GDPR.

Design/methodology/approach

The paper uses the Levy and Ellis’ narrative review of literature methodology, which is based on constructivist theory posited by Lincoln and Guba. Using five information systems and computer science databases, the researchers searched for studies using the keywords GDPR and blockchain, using a forward and backward search technique. The search identified a corpus of 416 candidate studies, from which the researchers applied pre-established criteria to select 39 studies. The researchers mined this corpus for concepts, which they clustered into themes. Using the accepted computer science practice of privacy by design, the researchers combined the clustered themes into the paper’s posited framework.

Findings

The paper posits a framework that provides architectural tactics for designing a blockchain that follows GDPR to enhance privacy. The framework explicitly addresses the challenges of GDPR compliance using the unimagined decentralized storage of personal data. The framework addresses the blockchain–GDPR tension by establishing trust between a business and its customers vis-à-vis storing customers’ data. The trust is established through blockchain’s capability of providing the customer with private keys and control over their data, e.g. processing and access.

Research limitations/implications

The paper provides a framework that demonstrates that blockchain technology can be designed for use in GDPR compliant solutions. In using the framework, a blockchain-based solution provides the ability to audit and monitor privacy measures, demonstrates a legal justification for processing activities, incorporates a data privacy policy, provides a map for data processing and ensures security and privacy awareness among all actors. The research is limited to a focus on blockchain–GDPR compliance; however, future research is needed to investigate the use of the framework in specific domains.

Practical implications

The paper posits a framework that identifies the strategies and tactics necessary for GDPR compliance. Practitioners need to compliment the framework with rigorous privacy risk management, i.e. conducting a privacy risk analysis, identifying strategies and tactics to address such risks and preparing a privacy impact assessment that enhances accountability and transparency of a blockchain.

Originality/value

With the increasingly strategic use of data by businesses and the contravening growth of data privacy regulation, alternative technologies could provide businesses with a means to nurture trust with its customers regarding collected data. However, it is commonly assumed that the decentralized approach of blockchain technology cannot be applied to this business need. This paper posits a framework that enables a blockchain to be designed that follows the GDPR; thereby, providing an alternative for businesses to collect customers’ data while ensuring the customers’ trust.

Details

Digital Policy, Regulation and Governance, vol. 22 no. 5/6
Type: Research Article
ISSN: 2398-5038

Keywords

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