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Article
Publication date: 7 October 2014

Maria Filipa Mourão, Ana Cristina Braga and Pedro Nuno Oliveira

The purpose of this paper is to use the kernel method to produce a smoothed receiver operating characteristic (ROC) curve and show how baby gender can influence Clinical…

Abstract

Purpose

The purpose of this paper is to use the kernel method to produce a smoothed receiver operating characteristic (ROC) curve and show how baby gender can influence Clinical Risk Index for Babies (CRIB) scale according to survival risks.

Design/methodology/approach

To obtain the ROC curve, conditioned by covariates, two methods may be followed: first, indirect adjustment, in which the covariate is first modeled within groups and then by generating a modified distribution curve; second, direct smoothing in which covariate effects is modeled within the ROC curve itself. To verify if new-born gender and weight affects the classification according to the CRIB scale, the authors use the direct method. The authors sampled 160 Portuguese babies.

Findings

The smoothing applied to the ROC curves indicates that the curve's original shape does not change when a bandwidth h=0.1 is used. Furthermore, gender seems to be a significant covariate in predicting baby deaths. A higher value was obtained for the area under curve (AUC) when conditional on female babies.

Practical implications

The challenge is to determine whether gender discriminates between dead and surviving babies.

Originality/value

The authors constructed empirical ROC curves for CRIB data and empirical ROC curves conditioned on gender. The authors calculate the corresponding AUC and tested the difference between them. The authors also constructed smooth ROC curves for two approaches.

Details

International Journal of Health Care Quality Assurance, vol. 27 no. 8
Type: Research Article
ISSN: 0952-6862

Keywords

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Article
Publication date: 24 March 2021

Rasmus Gahrn-Andersen

Secchi and Cowley (2016, 2018) propose a Radical approach to Organizational Cognition (ROC) as a way of studying cognitive processes in organizations. What distinguishes…

Abstract

Purpose

Secchi and Cowley (2016, 2018) propose a Radical approach to Organizational Cognition (ROC) as a way of studying cognitive processes in organizations. What distinguishes ROC from the established research on Organizational Cognition is that it remains faithful to radical, anti-representationalist principles of contemporary cognitive science. However, it is imperative for proponents of ROC to legitimize their approach by considering how it differs from the established research approach of Distributed Cognition (DCog). DCog is a potential contender to ROC in that it not only counters classical approaches to cognition but also provides valuable insights into cognition in organizational settings.

Design/methodology/approach

The paper adopts a conceptual/theoretical approach that expands Secchi and Cowley's introduction of ROC.

Findings

The paper shows that DCog research presupposes a task-specification requirement, which entails that cognitive tasks are well-defined. Consequently, DCog research neglects cases of organizational becoming where tasks cannot be clearly demarcated for the or are well-known to the organization. This is the case with the introduction of novel tasks or technical devices. Moreover, the paper elaborates on ROC's 3M model by linking it with insights from the literature on organizational change. Thus, it explores how organizing can be explored as an emergent phenomenon that involves micro, meso and macro domain dynamics, which are shaped by synoptic and performative changes.

Originality/value

The present paper explores new grounds for ROC by not only expanding on its core model but also showing its potential for informing organizational theory and radical cognitive science research.

Details

International Journal of Organization Theory & Behavior, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1093-4537

Keywords

Content available
Article
Publication date: 30 July 2020

Alaa Tharwat

Classification techniques have been applied to many applications in various fields of sciences. There are several ways of evaluating classification algorithms. The…

Abstract

Classification techniques have been applied to many applications in various fields of sciences. There are several ways of evaluating classification algorithms. The analysis of such metrics and its significance must be interpreted correctly for evaluating different learning algorithms. Most of these measures are scalar metrics and some of them are graphical methods. This paper introduces a detailed overview of the classification assessment measures with the aim of providing the basics of these measures and to show how it works to serve as a comprehensive source for researchers who are interested in this field. This overview starts by highlighting the definition of the confusion matrix in binary and multi-class classification problems. Many classification measures are also explained in details, and the influence of balanced and imbalanced data on each metric is presented. An illustrative example is introduced to show (1) how to calculate these measures in binary and multi-class classification problems, and (2) the robustness of some measures against balanced and imbalanced data. Moreover, some graphical measures such as Receiver operating characteristics (ROC), Precision-Recall, and Detection error trade-off (DET) curves are presented with details. Additionally, in a step-by-step approach, different numerical examples are demonstrated to explain the preprocessing steps of plotting ROC, PR, and DET curves.

Details

Applied Computing and Informatics, vol. 17 no. 1
Type: Research Article
ISSN: 2634-1964

Keywords

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Article
Publication date: 1 February 2016

Avraham Levi

– The purpose of this paper is to explain why ROC analysis is an inappropriate replacement for probative analysis in lineup research.

Abstract

Purpose

The purpose of this paper is to explain why ROC analysis is an inappropriate replacement for probative analysis in lineup research.

Design/methodology/approach

Taking as the medical example comparing two methods to detect the presence of a malignant tumor (Mickes et al., 2012), and operationally defining ROC analysis: radiologists are shown the results from two methods. Their confidence judgments create a graph of correct identifications by mistaken ones. The author can compare the methods on radiologists’ ability to differentiate sick from healthy. Lineup researchers create two distinct lineups. In target-present lineups, witnesses differentiate between the target and the foils, not the target and the innocent suspect. In target-absent lineups, witnesses cannot even differentiate between innocent suspects and foils, having seen none.

Findings

Eyewitness ROC curves are similar to probative analysis, but provide less useful information.

Research limitations/implications

Researchers ware warned against using ROC when conducting lineup research.

Originality/value

Preventing inappropriate use of ROC analysis.

Details

Journal of Criminal Psychology, vol. 6 no. 1
Type: Research Article
ISSN: 2009-3829

Keywords

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Article
Publication date: 13 November 2007

Stylianos Z. Xanthopoulos and Christos T. Nakas

The purpose of this article is to introduce Receiver Operating Characteristic (ROC) surfaces and hyper‐surfaces within a banking context as natural generalizations of the…

Abstract

Purpose

The purpose of this article is to introduce Receiver Operating Characteristic (ROC) surfaces and hyper‐surfaces within a banking context as natural generalizations of the ROC curve.

Design/methodology/approach

Nonparametric ROC analysis using U‐statistics theory was used.

Findings

Application of the proposed methodology on data from a small size Greek bank illustrates the usefulness of ROC analysis for scoring systems assessment. The area under the ROC curve and the volume under the ROC surface and hyper‐surface are useful diagnostic indices for the assessment of credit rating systems and scorecards. The notion of statistical significance is not adequate for the evaluation of the loan granting strategy of a financial institution.

Originality/value

This article will be of value to financial institutions during the process of evaluation/validation of rating models.

Details

The Journal of Risk Finance, vol. 8 no. 5
Type: Research Article
ISSN: 1526-5943

Keywords

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Article
Publication date: 1 July 2003

Ana Cristina Braga and Pedro Oliveira

Receiver operating characteristic (ROC) analysis is a powerful tool to measure and specify the problems with diagnostic performance in medicine. Describes this analysis…

Abstract

Receiver operating characteristic (ROC) analysis is a powerful tool to measure and specify the problems with diagnostic performance in medicine. Describes this analysis and the importance of the index area under ROC curve, using some examples to demonstrate its application. The study was conducted on two sets of new‐borns with very low birth weight, coming from neonatal intensive care units from Portuguese hospitals. The first application uses correlated samples, and aims to define which of the five indices of clinical seriousness can be considered the best to evaluate the risk of death for babies with very low birth weight. In the second application, regarding independent samples, compares four Portuguese hospitals, the aim being to identify the neonatal intensive care unit which presents the best performance in terms of care to the new‐borns, i.e. evaluated through the comparison of the clinical severity indices.

Details

International Journal of Health Care Quality Assurance, vol. 16 no. 4
Type: Research Article
ISSN: 0952-6862

Keywords

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Article
Publication date: 1 May 2004

Shirley A. Hopkins, Winter Nie and Willie E. Hopkins

Assesses differences in the economies of Taiwan and China to determine whether or not perceptions of quality management differences exist among managers of electronic…

Abstract

Assesses differences in the economies of Taiwan and China to determine whether or not perceptions of quality management differences exist among managers of electronic firms in the two countries. Statistical results suggest that these two groups of managers not only differ in how they define quality, they also differ in their beliefs about the relationship between quality management and organizational outcomes, the extent to which quality management is practiced in the firm, and how the quality of their products compares with products produced by competitors in other countries.

Details

International Journal of Quality & Reliability Management, vol. 21 no. 4
Type: Research Article
ISSN: 0265-671X

Keywords

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Book part
Publication date: 7 September 2018

Dean Karalekas

This offers an introduction to the ROC army with a focus on its influential role in post-revolution society, the retreat to Taiwan, and its transformation over the…

Abstract

This offers an introduction to the ROC army with a focus on its influential role in post-revolution society, the retreat to Taiwan, and its transformation over the decades. Originally called the National Revolutionary Army at its inception in 1925 in China, it was renamed the Republic of China Armed Forces in 1947. Since 1949, the force’s primary goal was the ROC government’s objective of retaking the mainland (China) from the Communists. As a result of its history, the military has long been regarded by most Hokkien-speaking Taiwanese (those whose ancestors moved to the island from the 17th century, as opposed to the so-called Mainlanders who arrived from mainland China in following the 1949 KMT defeat at the hands of the Communists) as being the “KMT army.” The extent to which this perception persists is very much of interest when determining the civil–military relationship in Taiwan. Thus, conditions exist for low popular regard for the military, especially as regards a military career. There exists a situation in which Taiwan society has moved forward, both economically as well as politically, from dictatorship, through democratization, and into a truly open and free society dedicated to fairness and equality, and yet the security situation remains unchanged, with the threat of invasion remaining ever-present. As a result, the military tasked with confronting this threat has remained one of the largest social organs on the island resistant to change.

Details

Civil-Military Relations in Taiwan
Type: Book
ISBN: 978-1-78756-482-4

Keywords

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Article
Publication date: 1 January 1996

Timothy E. Burson and Robert L. Lippert

The history and divestiture of the Bell System is of immediate importance to several economies around the globe, especially those undergoing the change from state owned…

Abstract

The history and divestiture of the Bell System is of immediate importance to several economies around the globe, especially those undergoing the change from state owned operations to private ownership. Similarly, those economies experiencing rapid expansion of telecommunications can also learn from the experiences of AT&T's development, maturity, and subsequent divestiture. In addition to a brief history, this study examines preliminary empirical evidence which suggests agency costs, particularly those associated with free cash flow, were reduced following the divestiture.

Details

Studies in Economics and Finance, vol. 16 no. 2
Type: Research Article
ISSN: 1086-7376

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Article
Publication date: 1 July 1950

S.S. Schaetzel

A method of three dimensional plotting is adopted, where the ROC at any station on the wing is plotted vertically on a base representing the maximum icing conditions…

Abstract

A method of three dimensional plotting is adopted, where the ROC at any station on the wing is plotted vertically on a base representing the maximum icing conditions (FIG. 5). This allows a rapid estimate of the ROC at any icing condition. Also, by plotting the isothermal lines on the base and on the surface representing the ROC (FIG. 10), an immediate estimate of the maximum rate of heat supply at a given temperature is possible. (Since the amount of heat lost by convection is constant along an isothermal line.) By plotting those maxima against the ambient temperature, the most severe icing condition may be established. It is then sufficient to consider only the above condition in the design of the de‐icing system, all other combinations of the icing parameters producing a less critical heat requirement. It has also been found that the relation between the drop size (d) and the ROC (at any given speed between 150 and 350 f.p.s.) is almost linear for drop sizes between 10 and 40 microns. (cf. FIG. 6, REF. 3.) A general relation, of the form: ROC=Am(d‐D) is then established between the rate of catch, the liquid water content and the drop size. By using graphs giving the variation of the coefficients ‘A’ and ‘D’ with speed and position along the wing, it is possible to have a complete estimate of the severity of icing in a small fraction of time formerly required to complete the calculations.

Details

Aircraft Engineering and Aerospace Technology, vol. 22 no. 7
Type: Research Article
ISSN: 0002-2667

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