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Book part
Publication date: 30 August 2019

Timothy Cogley and Richard Startz

Standard estimation of ARMA models in which the AR and MA roots nearly cancel, so that individual coefficients are only weakly identified, often produces inferential…

Abstract

Standard estimation of ARMA models in which the AR and MA roots nearly cancel, so that individual coefficients are only weakly identified, often produces inferential ranges for individual coefficients that give a spurious appearance of accuracy. We remedy this problem with a model that uses a simple mixture prior. The posterior mixing probability is derived using Bayesian methods, but we show that the method works well in both Bayesian and frequentist setups. In particular, we show that our mixture procedure weights standard results heavily when given data from a well-identified ARMA model (which does not exhibit near root cancellation) and weights heavily an uninformative inferential region when given data from a weakly-identified ARMA model (with near root cancellation). When our procedure is applied to a well-identified process the investigator gets the “usual results,” so there is no important statistical cost to using our procedure. On the other hand, when our procedure is applied to a weakly identified process, the investigator learns that the data tell us little about the parameters – and is thus protected against making spurious inferences. We recommend that mixture models be computed routinely when inference about ARMA coefficients is of interest.

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Topics in Identification, Limited Dependent Variables, Partial Observability, Experimentation, and Flexible Modeling: Part A
Type: Book
ISBN: 978-1-78973-241-2

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Book part
Publication date: 30 August 2019

Abstract

Details

Topics in Identification, Limited Dependent Variables, Partial Observability, Experimentation, and Flexible Modeling: Part A
Type: Book
ISBN: 978-1-78973-241-2

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Article
Publication date: 5 October 2015

Siti Ruhliah Lizarose Samion, Mohamed Sukri Mat Ali and Aminudin Abu

This paper aims to investigate the aerodynamic sound generated from flow over bluff bodies at a high Reynolds number. By taking circular and square cylinders as two…

Abstract

Purpose

This paper aims to investigate the aerodynamic sound generated from flow over bluff bodies at a high Reynolds number. By taking circular and square cylinders as two representative geometries for the cross-section of bluff bodies, this study aims to clarify the difference in flow formation and sound generation between the two types of bluff bodies. Furthermore, the possibility for a downstream flat plate to be used as sound cancellation passive mechanism is also discussed in this study.

Design/methodology/approach

Sound source from the near field is numerically solved by using the Unsteady Reynolds-Averaged Navier Stokes equations. While for the sound at far-field, the compact sound theory of Curle’s analogy is used.

Findings

Magnitude of the generated sound is dominant by the aerodynamic forcer fluctuations, i.e. lift and drag, where the lift fluctuation gives the strongest influence on the sound generation. The square cylinder emits 4.7 dB higher than the sound emitted from flow over the circular cylinder. This relates to the longer vortex formation length for the case of square cylinder that provides space for more vortex to dissipate. It is suggested that downstream flat plate is possible to be applied for a sound cancellation mechanism for the case of circular cylinder, but it would be more challenging for the case of square cylinder.

Practical implications

This study include implications for the development of noise reduction study especially in high-speed vehicles such as the aircrafts and high-speed trains.

Originality/value

This study identified that there is possible method for sound cancellation in flow over bluff body cases by using passive control method, even in flow at high Reynolds number.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 87 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 14 August 2017

Huey Peng Loh, Dirk Frans de Korne, Soon Phaik Chee and Ranjana Mathur

Wrong lens implants have been associated with the highest frequency of medical errors in cataract surgery. The purpose of this paper is to explore the use of the Systems…

Abstract

Purpose

Wrong lens implants have been associated with the highest frequency of medical errors in cataract surgery. The purpose of this paper is to explore the use of the Systems Engineering Initiative for Patient Safety (SEIPS) framework to sustainably reduce wrong intraocular lens (IOL) implants in cataract surgery.

Design/methodology/approach

In this mixed-methods study, the SEIPS framework was used to analyse a series of (near) misses of IOL implants in a national tertiary specialty hospital in Singapore. A series of interventions was developed and applied in the case hospital. Risk assessment audits were done before the interventions (2012; n=6,111 surgeries), during its implementation (n=7,475) and in the two years post-interventions (2013-2015; n=39,390) to compare the wrong IOL-rates.

Findings

Although the absolute number of incidents was low, the incident rate decreased from 4.91 before to 2.54 per 10,000 cases after. Near miss IOL error decreased from 5.89 before to 3.55 per 1,000 cases after. The number of days between two IOL incidents increased from 35 to an initial peak of 385 before stabilizing on 56. The large variety of available IOL types and vendors was found as the main root cause of wrong implants that required reoperation.

Practical implications

The SEIPS framework seems to be helpful to assess components involved and develop sustainable quality and safety interventions that intervene at different levels of the system.

Originality/value

The SEIPS model is supportive to address differences between person and system root causes comprehensively and thereby foster quality and patient safety culture.

Details

International Journal of Health Care Quality Assurance, vol. 30 no. 6
Type: Research Article
ISSN: 0952-6862

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Article
Publication date: 1 January 1967

THE recent lecture by Professor David Keith‐Lucas, M.A., M.l.Mech.E., F.R.Ae.S., on ‘The British Aircraft Industry and its Future’ must be regarded as essential reading…

Abstract

THE recent lecture by Professor David Keith‐Lucas, M.A., M.l.Mech.E., F.R.Ae.S., on ‘The British Aircraft Industry and its Future’ must be regarded as essential reading for all those concerned with the industry. In order to give his paper the prominence it deserves, and so that the text can be given almost in full, it takes the place of the Leader for this issue.

Details

Aircraft Engineering and Aerospace Technology, vol. 39 no. 1
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 January 1978

The Equal Pay Act 1970 (which came into operation on 29 December 1975) provides for an “equality clause” to be written into all contracts of employment. S.1(2) (a) of the…

Abstract

The Equal Pay Act 1970 (which came into operation on 29 December 1975) provides for an “equality clause” to be written into all contracts of employment. S.1(2) (a) of the 1970 Act (which has been amended by the Sex Discrimination Act 1975) provides:

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Managerial Law, vol. 21 no. 1
Type: Research Article
ISSN: 0309-0558

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Article
Publication date: 7 October 2014

Bee Yee Liau and Pei Pei Tan

The purpose of this paper is to study the consumer opinion towards the low-cost airlines or low-cost carriers (LCCs) (these two terms are used interchangeably) industry in…

Abstract

Purpose

The purpose of this paper is to study the consumer opinion towards the low-cost airlines or low-cost carriers (LCCs) (these two terms are used interchangeably) industry in Malaysia to better understand consumers’ needs and to provide better services. Sentiment analysis is undertaken in revealing current customers’ satisfaction level towards low-cost airlines.

Design/methodology/approach

About 10,895 tweets (data collected for two and a half months) are analysed. Text mining techniques are used during data pre-processing and a mixture of statistical techniques are used to segment the customers’ opinion.

Findings

The results with two different sentiment algorithms show that there is more positive than negative polarity across the different algorithms. Clustering results show that both K-Means and spherical K-Means algorithms delivered similar results and the four main topics that are discussed by the consumers on Twitter are customer service, LCCs tickets promotions, flight cancellations and delays and post-booking management.

Practical implications

Gaining knowledge of customer sentiments as well as improvements on the four main topics discussed in this study, i.e. customer service, LCCs tickets promotions, flight cancellations or delays and post-booking management will help LCCs to attract more customers and generate more profits.

Originality/value

This paper provides useful insights on customers’ sentiments and opinions towards LCCs by utilizing social media information.

Details

Industrial Management & Data Systems, vol. 114 no. 9
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 1 January 1977

A distinction must be drawn between a dismissal on the one hand, and on the other a repudiation of a contract of employment as a result of a breach of a fundamental term…

Abstract

A distinction must be drawn between a dismissal on the one hand, and on the other a repudiation of a contract of employment as a result of a breach of a fundamental term of that contract. When such a repudiation has been accepted by the innocent party then a termination of employment takes place. Such termination does not constitute dismissal (see London v. James Laidlaw & Sons Ltd (1974) IRLR 136 and Gannon v. J. C. Firth (1976) IRLR 415 EAT).

Details

Managerial Law, vol. 20 no. 1
Type: Research Article
ISSN: 0309-0558

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Article
Publication date: 1 May 1977

The case, briefly reported in the last issue of BFJ, an appeal to a Milk and Dairies Tribunal arising out of a local authority's refusal to grant a licence to a milk…

Abstract

The case, briefly reported in the last issue of BFJ, an appeal to a Milk and Dairies Tribunal arising out of a local authority's refusal to grant a licence to a milk distributor because he failed to comply with a requirement that he should provide protective curtains to his milk floats, was a rare and in many ways, an interesting event. The Tribunal in this case was set up under reg. 16(2) (f), Milk (Special Designation) Regulations, 1963, constituted in accordance with Part I, clause 2 (2), Schedule 4 of the Regulations. Part II outlines procedure for such tribunals. The Tribunal is similar to that authorized by S.30, Food and Drugs Act, 1955, which deals with the registration of dairymen, dairy farms and farmers, and the Milk and Dairies (General) Regulations, 1959. Part II, Schedule 2 of the Act provided for reference to a tribunal of appeals against refusal or cancellation of registration by the Ministry, but of producers only. A local authority's power to refuse to register or cancellation contained in Part I, Schedule 2 provided for no such reference and related to instances where “public health is or is likely to be endangered by any act or default” of such a person, who was given the right of appeal against refusal to register, etc., to a magistrates' court. No such limitation exists in respect of the revoking, suspending, refusal to renew a licence under the Milk (Special Designation) Regulations, 1963; an appeal against same lies to the Minister, who must refer the matter to a tribunal, if the person so requests. This occurred in the case under discussion.

Details

British Food Journal, vol. 79 no. 5
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 30 December 2019

Deoraj Prajapati and Gaurav Suman

The purpose of this paper is to implement Six Sigma approach to decrease the length of stay (LOS) of neonatal jaundice patients in an Indian government rural hospital…

Abstract

Purpose

The purpose of this paper is to implement Six Sigma approach to decrease the length of stay (LOS) of neonatal jaundice patients in an Indian government rural hospital situated in northern hill region.

Design/methodology/approach

Six Sigma’s Define–Measure–Analyse–Improve–Control procedure is applied in order to decrease the LOS of neonatal jaundice patients. The mean and standard deviation have been computed as 34.53 and 20.01 h, respectively. The cause and effect diagram is used in the “Analyse” phase of the Six Sigma. The regression analysis and GEMBA observation techniques are used to validate the causes identified through cause and effect diagram.

Findings

The waiting time for registration, waiting time for tests, waiting time for phototherapy and time for discharge implementation are the main factors that are responsible for longer LOS. Based on the identified root causes, some recommendations are suggested to the hospital administration and staff members in order to reduce the LOS.

Research limitations/implications

The present research is limited to provide recommendations to the hospital administration to reduce LOS and it entirely depends upon the implementation of the administration. However, target of administration is to reduce the LOS up to 24 h.

Practical implications

Six Sigma model will reduce bottlenecks in LOS and enhance service quality of hospital. The developed regression model will help the doctors and staff members to assess and control the LOS by controlling and minimising the independent variables.

Social implications

The project will directly provide benefits to society, as LOS will decrease and patients’ satisfaction will automatically increase.

Originality/value

Six Sigma is a developed methodology, but its application in paediatric department is very limited. This is the first ever study of applying Six Sigma for neonatal jaundice patients in India.

Details

International Journal of Health Care Quality Assurance, vol. 33 no. 1
Type: Research Article
ISSN: 0952-6862

Keywords

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