Books and journals Case studies Expert Briefings Open Access
Advanced search

Search results

1 – 10 of over 168000
To view the access options for this content please click here
Book part
Publication date: 14 October 2009

Vehicle Design and Protective Devices

Rune Elvik, Alena Høye, Truls Vaa and Michael Sørensen

HTML
PDF (1.3 MB)
EPUB (4.3 MB)

Abstract

Details

The Handbook of Road Safety Measures
Type: Book
DOI: https://doi.org/10.1108/9781848552517-010
ISBN: 978-1-84855-250-0

To view the access options for this content please click here
Article
Publication date: 1 April 1977

CONTROL ANALYSIS IN BEHAVIOURAL SCIENCE

R. HIRSIG

An off‐line optimization method is described which allows the determination of “optimal” control strategies in a behavioural systems analysis. The method is based on the…

HTML
PDF (569 KB)

Abstract

An off‐line optimization method is described which allows the determination of “optimal” control strategies in a behavioural systems analysis. The method is based on the theory of learning systems, using a phenomenalistic model of the behavioural process for control experiments. There are no restrictions concerning the degree or order of this model. An outline of an investigation in social psychology demonstrates an application of the proposed method. The analysed data are the same as those used in a report on “System identification in behavioural science” previously published in this journal. This allows comparison of two different approaches to behavioural systems analysis by means of a phenomenalistic model.

Details

Kybernetes, vol. 6 no. 4
Type: Research Article
DOI: https://doi.org/10.1108/eb005458
ISSN: 0368-492X

To view the access options for this content please click here
Article
Publication date: 1 January 2013

State and control system variables sensitivity to rotor asymmetry in the induction motor drive

Piotr Kołodziejek

The aim of this paper is to undertake analysis and comparison of the closed‐loop and sensorless control systems sensitivity to the broken rotor for diagnostic purposes…

HTML
PDF (495 KB)

Abstract

Purpose

The aim of this paper is to undertake analysis and comparison of the closed‐loop and sensorless control systems sensitivity to the broken rotor for diagnostic purposes. For the same vector control system induction motor drive analysis concerning operation with the asymmetric motor, broken rotor fault handling and operation were investigated. Reliability, range of stable operation, fault symptoms and application of diagnosis methods based on control system variables utilization was analyzed.

Design/methodology/approach

Induction motor drive vector control system synthesis was applied using the multiscalar variables of the machine model with nonlinear feedback linearization applied to use classical cascaded PI controllers for the speed‐torque and flux decoupled control. Speed observer was applied for the rotor flux and rotor speed estimation for the sensorless control system synthesis.

Findings

Relative sensitivity of the state and control system variables to broken rotor fault based on experimental results for the closed‐loop and sensorless control systems is presented and compared. Drawbacks of using the MCSA analysis for the rotor fault diagnosis in the closed‐loop and sensorless control systems are pointed. Advantages and drawbacks of the state space estimators filtering characteristics in the sensorless control system are described.

Practical implications

Asymmetric IM motor drive handling and diagnosis. Broken rotor range diagnosis inconsistency using the popular MCSA method should be considered in the closed‐loop and sensorless control system of the induction motor drive. Depending on the IM motor drive application and the operation requirements the results can be used for asymmetric machine proper handling, choosing proper control system structure and control system variables for rotor fault early diagnosis.

Originality/value

Sensitivity of the state and control system variables to broken rotor fault based on experimental results for the closed‐loop and sensorless control systems is presented, which implies motor handling procedures and fault diagnosis.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 1
Type: Research Article
DOI: https://doi.org/10.1108/03321641311293795
ISSN: 0332-1649

Keywords

  • Induction motor drive
  • Broken rotor handling and diagnosis
  • Sensorless control
  • Closed‐loop control
  • Fault symptoms sensitivity analysis
  • Torque
  • Electric motors

To view the access options for this content please click here
Article
Publication date: 8 May 2009

Broken rotor bar impact on sensorless control of induction machine

Piotr Kołodziejek and Elżbieta Bogalecka

The purpose of this paper is analysis of the sensorless control system of induction machine with broken rotor for diagnostic purposes. Increasing popularity of sensorless…

HTML
PDF (548 KB)

Abstract

Purpose

The purpose of this paper is analysis of the sensorless control system of induction machine with broken rotor for diagnostic purposes. Increasing popularity of sensorless controlled variable speed drives requires research in area of reliability, range of stable operation, fault symptoms and application of diagnosis methods.

Design/methodology/approach

T transformation used for conversion of instantaneous rotor currents electrical circuit representation to space vector components is investigated to apply with closed‐loop modeling algorithm. Evaluation of the algorithm is based on analysis of asymmetry influence to the orthogonal and zero components of space vector representation. Multiscalar model of the machine and selected structures of state observers are used for sensorless control system synthesis. Proposed method of frequency characteristics calculation is used for state observers analysis in open‐loop operation.

Findings

New algorithm of applying the T transformation allows for closed‐loop and sensorless control system simulation with asymmetric machine due to broken rotor. Compensating effect of the closed‐loop control system with speed measurements and diagnosis information in control system variables are identified. Proposed frequency analysis of state observers is presented and applied. Variables with amplified characteristic frequency components related to rotor asymmetry are compared for selected structures of state observers and with closed‐loop and open‐loop operation. Method of improving the sensorless system stability is proposed.

Practical implications

In closed‐loop and sensorless control system rotor fault can be diagnosed by using PI output controllers variables. Compensating effect of mechanical variables sets limitation to specified diagnosis methods. Rotor asymmetry affects sensorless control system stability depending on estimator structure.

Originality/value

This paper concentrates upon sensorless control system operation with machine asymmetry and indicates rotor fault symptoms.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 28 no. 3
Type: Research Article
DOI: https://doi.org/10.1108/03321640910940837
ISSN: 0332-1649

Keywords

  • Control systems
  • Control technology
  • Electric motors
  • Breakdowns

To view the access options for this content please click here
Book part
Publication date: 24 October 2019

Failure to Rescue Event Mitigation System Assessment: A Mixed-methods Approach to Analysis of Complex Adaptive Systems

Susan P. McGrath, Emily Wells, Krystal M. McGovern, Irina Perreard, Kathleen Stewart, Dennis McGrath and George Blike

Although it is widely acknowledged that health care delivery systems are complex adaptive systems, there are gaps in understanding the application of systems engineering…

HTML
PDF (1.2 MB)
EPUB (754 KB)

Abstract

Although it is widely acknowledged that health care delivery systems are complex adaptive systems, there are gaps in understanding the application of systems engineering approaches to systems analysis and redesign in the health care domain. Commonly employed methods, such as statistical analysis of risk factors and outcomes, are simply not adequate to robustly characterize all system requirements and facilitate reliable design of complex care delivery systems. This is especially apparent in institutional-level systems, such as patient safety programs that must mitigate the risk of infections and other complications that can occur in virtually any setting providing direct and indirect patient care. The case example presented here illustrates the application of various system engineering methods to identify requirements and intervention candidates for a critical patient safety problem known as failure to rescue. Detailed descriptions of the analysis methods and their application are presented along with specific analysis artifacts related to the failure to rescue case study. Given the prevalence of complex systems in health care, this practical and effective approach provides an important example of how systems engineering methods can effectively address the shortcomings in current health care analysis and design, where complex systems are increasingly prevalent.

Details

Structural Approaches to Address Issues in Patient Safety
Type: Book
DOI: https://doi.org/10.1108/S1474-823120190000018006
ISBN: 978-1-83867-085-6

Keywords

  • Systems analysis
  • failure to rescue
  • patient safety
  • system design
  • ideal rescue care system
  • complication management

To view the access options for this content please click here
Article
Publication date: 5 September 2016

Integrative contingency-based framework of MCS: the case of post-secondary education

Carol Pomare and Anthony Berry

The purpose of this paper is to explore whether and how changes in the management control systems (MCS) of post-secondary institutions (PSIs) in Western Canada can be…

HTML
PDF (438 KB)

Abstract

Purpose

The purpose of this paper is to explore whether and how changes in the management control systems (MCS) of post-secondary institutions (PSIs) in Western Canada can be described and explained in terms of formal and informal MCS; and whether and how changes in the MCS of PSIs in Western Canada can be described and explained in terms of an integrative contingency-based framework of MCS based on regulatory accountability systems, competitive markets and organizational culture?

Design/methodology/approach

The empirical research was undertaken with an exploratory mixed design. The first phase involved descriptive univariate and bivariate statistics as well as non-parametric statistics computed on data from annual reports and financial statements of 46 PSIs in Western Canada to quantitatively explore MCS. The second phase involved the grounded theory (GT) analysis of annual reports of 46 PSIs in Western Canada to qualitatively explore formal MCS in relation to changes in contingencies. The third phase involved the GT analysis of 20 semi-structured interviews of senior managers from PSIs in Western Canada to qualitatively explore informal MCS in relation to formal MCS and changes in contingencies.

Findings

The research showed that emphasis on formal MCS in Western Canadian PSIs resulted in biased compliance within informal MCS. The exploratory research also demonstrated that the distinction between formal and informal MCS was better understood in a wider framing of MCS in terms of regulatory accountability systems, competitive markets and organizational culture.

Originality/value

This research led to the elaboration of an exploratory theoretical framework to subsume the distinction between formal and informal MCS into an integrative contingency-based framework of MCS.

Details

Journal of Accounting & Organizational Change, vol. 12 no. 3
Type: Research Article
DOI: https://doi.org/10.1108/JAOC-02-2014-0013
ISSN: 1832-5912

Keywords

  • Management control systems
  • Case study
  • Post-secondary education
  • Contingencies
  • MCS

To view the access options for this content please click here
Article
Publication date: 1 October 2003

A study on industry and synthetic standard benchmarks in relational and object databases

Jia‐Lang Seng

Benchmarks are the vital tools in the performance measurement and evaluation of database management systems (DBMS), including the relational database management systems…

HTML
PDF (343 KB)

Abstract

Benchmarks are the vital tools in the performance measurement and evaluation of database management systems (DBMS), including the relational database management systems (RDBMS) and the object‐oriented/object‐relational database management systems (OODBMS/ORDBMS). Standard synthetic benchmarks have been used to assess the performance of RDBMS software. Other benchmarks have been utilized to appraise the performance of OODBMS/ORDBMS products. In this paper, an analytical framework of workload characterization to extensively and expansively examine the rationale and design of the industry standard and synthetic standard benchmarks is presented. This analytical framework of workload analysis is made up of four main components: the schema analysis, the operation analysis, the control analysis, and the system analysis. These analysis results are compiled and new concepts and perspectives of benchmark design are collated. Each analysis aspect is described and each managerial implication is discussed in detail.

Details

Industrial Management & Data Systems, vol. 103 no. 7
Type: Research Article
DOI: https://doi.org/10.1108/02635570310489214
ISSN: 0263-5577

Keywords

  • Databases
  • Benchmarking
  • Performance monitoring
  • Online operation
  • Relational databases
  • Object‐oriented databases

To view the access options for this content please click here
Article
Publication date: 1 October 2005

Internal auditing practices and internal control system

Faudziah Hanim Fadzil, Hasnah Haron and Muhamad Jantan

Two main objectives and they are: to determine whether the internal audit department of the companies listed in the Bursa Malaysia complies with the Standards for the…

HTML
PDF (163 KB)

Abstract

Purpose

Two main objectives and they are: to determine whether the internal audit department of the companies listed in the Bursa Malaysia complies with the Standards for the Professional Practice of Internal Auditors IIA (2000); and, to determine whether compliance to SPPIA will affect the quality of the internal control system of the company.

Design/methodology/approach

Two sets of questionnaires were used in the study. Internal auditing practices was measured by the items listed in the SPPIA and the internal control was measured by means of the statement on internal control: guidance for directors of public listed companies. The population used in this study was all the companies listed in the Bursa Malaysia in 2001. This study used both descriptive and inferential analyses.

Findings

It was found that management of internal audit department, professional proficiency, objectivity and review significantly influence the monitoring aspect of the internal control system. Scope of work and performance of audit work significantly influences the information and communication aspect of the internal control system while performance of audit work, professional proficiency and objectivity significantly influence the control environment aspect of the internal control system. The study also shows that management of internal audit department, performance of audit work, audit program and audit reporting significantly influences the risk assessment aspect of the internal control system. Lastly, performance of audit work and audit reporting significantly influences the control activities aspect of the internal control system.

Research limitations/implications

The research has contributed to the agency theory with respect to the bonding costs that management has to pay to the internal auditors for the best interest of the principals of the companies. Another important implication pertains to the extent of the internal auditing practices among internal auditors in Malaysian public listed companies. Research has also shown that the compliance with internal auditing practices partially influence certain aspects of the quality of the internal control system.

Originality/value

This is the first empirical study that has linked the compliance of the internal auditing function to the SPPIA and its effect on the internal control system.

Details

Managerial Auditing Journal, vol. 20 no. 8
Type: Research Article
DOI: https://doi.org/10.1108/02686900510619683
ISSN: 0268-6902

Keywords

  • Auditing
  • Auditing standards
  • Malaysia

To view the access options for this content please click here
Article
Publication date: 26 August 2014

Internal control over financial reporting: opportunities using the COBIT framework

Michele Rubino and Filippo Vitolla

The purpose of this paper is to analyze how the COBIT framework, integrated within the internal control framework, enables improvement in the quality of financial…

HTML
PDF (280 KB)

Abstract

Purpose

The purpose of this paper is to analyze how the COBIT framework, integrated within the internal control framework, enables improvement in the quality of financial reporting while helping to reduce or eliminate the material weaknesses (MWs) of internal control over financial reporting (ICFR). The Control Objectives for Information and Related Technology (COBIT) model is a framework for information technology (IT) management and IT governance. It is a supporting toolset that allows managers to bridge the gap between control requirements, technical issues and business risks. Preliminarily, the analysis in this paper illustrates how the Committee of Sponsoring Organizations (COSO) framework impacts on the MWs, highlighting strengths and weaknesses. This paper shows how these limits can be overcome with the use of the COBIT framework.

Design/methodology/approach

This is a conceptual paper that aims to highlight the relationship between COBIT and COSO, by illustrating how the IT processes reduce or eliminate the main MW categories.

Findings

The analysis indicates that the implementation of the COBIT framework, or more generally the adoption of effective IT controls, provides important benefits to the entire company or organization. IT control objectives have a direct impact on the IT control weaknesses and indirectly on the other categories of material weaknesses.

Practical implications

The adoption of the framework allows managers to implement effective ICFR. In particular, the COBIT approach provides managers with a more evolved tool in terms of compliance with the Sarbanes–Oxley Act requirements. This framework also improves the reliability of financial reporting in relation to the requirements of Public Company Accounting Oversight Board’s Auditing Standards No. 2 and 5.

Originality/value

The analysis provides an interdisciplinary approach, connecting accounting and information systems themes, and suggest solutions and tools than can help managers to address the internal control weaknesses. This paper addresses an area of relevance to both practitioners and academics and expands existing accounting literature.

Details

Managerial Auditing Journal, vol. 29 no. 8
Type: Research Article
DOI: https://doi.org/10.1108/MAJ-03-2014-1016
ISSN: 0268-6902

Keywords

  • Financial reporting
  • COBIT 5 framework
  • SOX
  • COSO framework
  • IT controls
  • Material weaknesses

To view the access options for this content please click here
Article
Publication date: 18 October 2011

Modeling and analysis of robotic wheel loading process in trim‐and‐final assembly

Heping Chen, Jianjun Wang, Biao Zhang and Thomas Fuhlbrigge

Moving production lines are widely used in many manufacturing factories, such as automotive and general industries. However, industrial robots are hardly used to perform…

HTML
PDF (487 KB)

Abstract

Purpose

Moving production lines are widely used in many manufacturing factories, such as automotive and general industries. However, industrial robots are hardly used to perform any tasks on the moving production lines. One of the main reasons is that it is difficult for conventional industrial robots to adjust to any sort of change. Therefore, the authors developed an industrial robotic system to track the random motion of the moving production lines while performing assembly processes. Before setting up a physical system to measure the system performance, it is desirable to develop a method to analyze the system performance. The purpose of this paper is to develop a performance analysis method for a robotic assembly system on a moving production line.

Design/methodology/approach

The developed system is based on the synergic combination of visual servoing and force control technology. Since it is difficult to model the system accurately, a second‐order system is used to approximate it. The system performance for force control and visual servoing is then analyzed. The tracking errors are calculated and compared with experimental results.

Findings

The developed method is evaluated using an experimental system and simulation. The simulation results are quite close to the experimental results. Hence, the developed method can be used to estimate the system performance.

Research limitations/implications

Since only one system is set up to validate the developed method, more testing is needed to generalize it.

Practical implications

The developed technology is validated using the experimental results and the results are promising. Even though there is a limitation, the developed method can be used to estimate the system performance before setting up a physical system.

Originality/value

This paper provides a system performance analysis method for a robotic assembly on a moving production line. It is important to estimate the system performance before setting up a physical system because it will save a lot of time and resources in the manufacturing floor.

Details

Industrial Robot: An International Journal, vol. 38 no. 6
Type: Research Article
DOI: https://doi.org/10.1108/01439911111179129
ISSN: 0143-991X

Keywords

  • Manufacturing systems
  • Assembly lines
  • Automation
  • Visual servoing
  • Force control
  • Industrial robot
  • Wheel loading

Access
Only content I have access to
Only Open Access
Year
  • Last week (443)
  • Last month (1605)
  • Last 3 months (4116)
  • Last 6 months (7984)
  • Last 12 months (15448)
  • All dates (168622)
Content type
  • Article (138621)
  • Book part (20773)
  • Earlycite article (5897)
  • Expert briefing (1908)
  • Case study (1422)
  • Executive summary (1)
1 – 10 of over 168000
Emerald Publishing
  • Opens in new window
  • Opens in new window
  • Opens in new window
  • Opens in new window
© 2021 Emerald Publishing Limited

Services

  • Authors Opens in new window
  • Editors Opens in new window
  • Librarians Opens in new window
  • Researchers Opens in new window
  • Reviewers Opens in new window

About

  • About Emerald Opens in new window
  • Working for Emerald Opens in new window
  • Contact us Opens in new window
  • Publication sitemap

Policies and information

  • Privacy notice
  • Site policies
  • Modern Slavery Act Opens in new window
  • Chair of Trustees governance statement Opens in new window
  • COVID-19 policy Opens in new window
Manage cookies

We’re listening — tell us what you think

  • Something didn’t work…

    Report bugs here

  • All feedback is valuable

    Please share your general feedback

  • Member of Emerald Engage?

    You can join in the discussion by joining the community or logging in here.
    You can also find out more about Emerald Engage.

Join us on our journey

  • Platform update page

    Visit emeraldpublishing.com/platformupdate to discover the latest news and updates

  • Questions & More Information

    Answers to the most commonly asked questions here