JOSEPH P. NOONAN and JAMES R. MARCUS
The problem of modelling stochastic systems when only a partial statistical description is available is considered. Specifically, a procedure is proposed for assigning an optimal…
Abstract
The problem of modelling stochastic systems when only a partial statistical description is available is considered. Specifically, a procedure is proposed for assigning an optimal joint probability model relating the input and output of the system where the partial statistical description becomes constraints. The Mutual Information functional is used to establish the model leading to a criteria which is optimal in an information theory sense. Results showing general solutions for cases of interest in digital communications as well as continuous systems with noise variance knowledge are given.
Joseph P. Noonan and James R. Marcus
The mathematical and theoretical development required for using the minimum mutual information technique in image restoration is presented. Results from an implementation of the…
Abstract
The mathematical and theoretical development required for using the minimum mutual information technique in image restoration is presented. Results from an implementation of the minimum mutual information technique are shown to demonstrate its capabilities. The results establish that minimum mutual information is a viable image restoration approach without the convergence problems usually associated with similar techniques.
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In many problems involving decision‐making under uncertainty, the underlying probability model is unknown but partial information is available. In some approaches to this problem…
Abstract
Purpose
In many problems involving decision‐making under uncertainty, the underlying probability model is unknown but partial information is available. In some approaches to this problem, the available prior information is used to define an appropriate probability model for the system uncertainty through a probability density function. When the prior information is available as a finite sequence of moments of the unknown probability density function (PDF) defining the appropriate probability model for the uncertain system, the maximum entropy (ME) method derives a PDF from an exponential family to define an approximate model. This paper, aims to investigate some optimality properties of the ME estimates.
Design/methodology/approach
For n>m, when the exact model can be best approximated by one of an infinite number of unknown PDFs from an n parameter exponential family. The upper bound of the divergence distance between any PDF from this family and the m parameter exponential family PDF defined by the ME method are derived. A measure of adequacy of the model defined by ME method is thus provided.
Findings
These results may be used to establish confidence intervals on the estimate of a function of the random variable when the ME approach is employed. Additionally, it is shown that when working with large samples of independent observations, a probability density function (PDF) can be defined from an exponential family to model the uncertainty of the underlying system with measurable accuracy. Finally, a relationship with maximum likelihood estimation for this case is established.
Practical implications
The so‐called known moments problem addressed in this paper has a variety of applications in learning, blind equalization and neural networks.
Originality/value
An upper bound for error in approximating an unknown density function, f(x) by its ME estimate based on m moment constraints, obtained as a PDF p(x, α) from an m parameter exponential family is derived. The error bound will help us decide if the number of moment constraints is adequate for modeling the uncertainty in the system under study. In turn, this allows one to establish confidence intervals on an estimate of some function of the random variable, X, given the known moments. It is also shown how, when working with a large sample of independent observations, instead of precisely known moment constraints, a density from an exponential family to model the uncertainty of the underlying system with measurable accuracy can be defined. In this case, a relationship to ML estimation is established.
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In the first decades of the nineteenth century to the first decade of the twentieth century, the US Federal and Supreme Courts heard several cases on the legal status of ships…
Abstract
In the first decades of the nineteenth century to the first decade of the twentieth century, the US Federal and Supreme Courts heard several cases on the legal status of ships. During this period, Chief Justice John Marshall and Justice Joseph Story determined that a ship was a legal person that was capable to contract and could be punished for wrongdoing. Over the nineteenth century, Marshall and Story also heard appeals on the illegal slave trade and on the status of fugitive slaves crossing state lines, cases that raised questions as to whether enslaved peoples were persons or property. Although Marshall and Story did not discuss the ship and the slave together, in this chapter, the author asks what might be gained in doing so. Specifically, what might a reading of the ship and the slave as juridical figures reveal about the history of legal personhood? The genealogy of positive and negative legal personhood that the author begins to trace here draws inspiration and guidance from scholars writing critically of slavery. In different ways, this literature emphasises the significance of maritime worlds to conceptions of racial terror, freedom, and fugitivity. Building on these insights, the author reads the ship and the slave as central characters in the history of legal personhood, a reading that highlights the interconnections between maritime law and the laws of slavery and foregrounds the changing intensities of Anglo imperial power and racial and colonial violence in shaping the legal person.
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Gohar F. Khan, Marko Sarstedt, Wen-Lung Shiau, Joseph F. Hair, Christian M. Ringle and Martin P. Fritze
The purpose of this paper is to explore the knowledge infrastructure of methodological research on partial least squares structural equation modeling (PLS-SEM) from a network…
Abstract
Purpose
The purpose of this paper is to explore the knowledge infrastructure of methodological research on partial least squares structural equation modeling (PLS-SEM) from a network point of view. The analysis involves the structures of authors, institutions, countries and co-citation networks, and discloses trending developments in the field.
Design/methodology/approach
Based on bibliometric data downloaded from the Web of Science, the authors apply various social network analysis (SNA) and visualization tools to examine the structure of knowledge networks of the PLS-SEM domain. Specifically, the authors investigate the PLS-SEM knowledge network by analyzing 84 methodological studies published in 39 journals by 145 authors from 106 institutions.
Findings
The analysis reveals that specific authors dominate the network, whereas most authors work in isolated groups, loosely connected to the network’s focal authors. Besides presenting the results of a country level analysis, the research also identifies journals that play a key role in disseminating knowledge in the network. Finally, a burst detection analysis indicates that method comparisons and extensions, for example, to estimate common factor model data or to leverage PLS-SEM’s predictive capabilities, feature prominently in recent research.
Originality/value
Addressing the limitations of prior systematic literature reviews on the PLS-SEM method, this is the first study to apply SNA to reveal the interrelated structures and properties of PLS-SEM’s research domain.
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Joseph F. Hair, Marko Sarstedt and Christian M. Ringle
Partial least squares structural equation modeling (PLS-SEM) is an important statistical technique in the toolbox of methods that researchers in marketing and other social…
Abstract
Purpose
Partial least squares structural equation modeling (PLS-SEM) is an important statistical technique in the toolbox of methods that researchers in marketing and other social sciences disciplines frequently use in their empirical analyses. The purpose of this paper is to shed light on several misconceptions that have emerged as a result of the proposed “new guidelines” for PLS-SEM. The authors discuss various aspects related to current debates on when or when not to use PLS-SEM, and which model evaluation metrics to apply. In addition, this paper summarizes several important methodological extensions of PLS-SEM researchers can use to improve the quality of their analyses, results and findings.
Design/methodology/approach
The paper merges literature from various disciplines, including marketing, strategic management, information systems, accounting and statistics, to present a state-of-the-art review of PLS-SEM. Based on these findings, the paper offers a point of orientation on how to consider and apply these latest developments when executing or assessing PLS-SEM-based research.
Findings
This paper offers guidance regarding situations that favor the use of PLS-SEM and discusses the need to consider certain model evaluation metrics. It also summarizes how to deal with endogeneity in PLS-SEM, and critically comments on the recent proposal to adjust PLS-SEM estimates to mimic common factor models that are the foundation of covariance-based SEM. Finally, this paper opposes characterizing common concepts and practices of PLS-SEM as “out-of-date” without providing well-substantiated alternatives and solutions.
Research limitations/implications
The paper paves the way for future discussions and suggests a way forward to reach consensus regarding situations that favor PLS-SEM use and its application.
Practical implications
This paper offers guidance on how to consider the latest methodological developments when executing or assessing PLS-SEM-based research.
Originality/value
This paper complements recently proposed “new guidelines” with the aim of offering a counter perspective on some strong claims made in the latest literature on PLS-SEM. It also clarifies some misconceptions regarding the application of PLS-SEM.
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This chapter proposes that corporate lawyers be studied as committed to their clients, asking how they advance exercises of power by those whom they have chosen to represent…
Abstract
This chapter proposes that corporate lawyers be studied as committed to their clients, asking how they advance exercises of power by those whom they have chosen to represent. Currently, corporate lawyers are studied as independent from their clients, asking how they resist client demands. Such research continues despite repeated findings that corporate lawyers are not independent. This chapter explains the puzzling persistence of independence by cultural understandings of both professionalism and law. It recovers a submerged historic voice in which corporate lawyers are judged by their position in a network of relations. It argues that it was the organization of the corporate law firm as a factory which allowed it to become a professional ideal. Market competition has led corporate law firms to move away from a factory model to one in which commitment to clients, not independence from them, is the organizing principle.
Venesser Fernandes, Winnie Wong and Michael Noonan
During the COVID-19 crisis in Victoria, Australia the complexity of school leadership increased greatly for school principals. This study focused on the lived experiences of early…
Abstract
Purpose
During the COVID-19 crisis in Victoria, Australia the complexity of school leadership increased greatly for school principals. This study focused on the lived experiences of early career principals in the independent school sector from March to November 2020 in Victoria, Australia. It investigates transformative work that was undertaken by these leaders in leading their schools over a protracted crisis.
Design/methodology/approach
The study builds on constructs of crisis leadership, adaptive leadership, agile leadership and emotional intelligence, exploring the leadership approaches undertaken by twenty-two early career principals in Victoria, Australia. Using a narrative inquiry approach, across three temporal points in 2020, storied productions drawn from the findings present four emergent types of emotionally intelligent leadership approaches undertaken by these principals. These leadership approaches are presented as the commander-leader, the conductor-leader, the gardener-leader and the engineer-leader with each approach demonstrating both organisational leadership approaches as well as individual leadership styles used by these principals as they led their schools.
Findings
The findings have direct implications for professional development programs focusing on aspiring principals and early career principals with emphasis on the importance of developing emotionally intelligent skillsets in principals for use during periods of rapid change or high crisis in schools. The findings present insight into the support useful for early career principals in the first five years of principalship.
Originality/value
This study uses a unique emotional intelligence approach to understand school leadership during and after a crisis.