An R implementation for generalized Birnbaum-Saunders distributions

The Birnbaum-Saunders (BS) model is a positively skewed statistical distribution that has received great attention in recent decades. A generalized version of this model was derived based on symmetrical distributions in the real line named the generalized BS (GBS) distribution. The R package named gbs was developed to analyze data from GBS models. This package contains probabilistic and reliability indicators and random number generators from GBS distributions. Parameter estimates for censored and uncensored data can also be obtained by means of likelihood methods from the gbs package. Goodness-of-fit and diagnostic methods were also implemented in this package in order to check the suitability of the GBS models. in this article, the capabilities and features of the gbs package are illustrated by using simulated and real data sets. Shape and reliability analyses for GBS models are presented. A simulation study for evaluating the quality and sensitivity of the estimation method developed in the package is provided and discussed. (C) 2008 Elsevier B.V. All rights reserved.

Asymptotic Skewness in Exponential Family Nonlinear Models

In this article, we give an asymptotic formula of order n(-1/2), where n is the sample size, for the skewness of the distributions of the maximum likelihood estimates of the parameters in exponencial family nonlinear models. We generalize the result by Cordeiro and Cordeiro ( 2001). The formula is given in matrix notation and is very suitable for computer implementation and to obtain closed form expressions for a great variety of models. Some special cases and two applications are discussed.

SPECIAL CHARACTERIZATIONS OF STANDARD DISCRETE MODELS

This article presents important properties of standard discrete distributions and its conjugate densities. The Bernoulli and Poisson processes are described as generators of such discrete models. A characterization of distributions by mixtures is also introduced. This article adopts a novel singular notation and representation. Singular representations are unusual in statistical texts. Nevertheless, the singular notation makes it simpler to extend and generalize theoretical results and greatly facilitates numerical and computational implementation.

Covariance matrix formula for Birnbaum-Saunders regression models

The Birnbaum-Saunders regression model is commonly used in reliability studies. We derive a simple matrix formula for second-order covariances of maximum-likelihood estimators in this class of models. The formula is quite suitable for computer implementation, since it involves only simple operations on matrices and vectors. Some simulation results show that the second-order covariances can be quite pronounced in small to moderate sample sizes. We also present empirical applications.

Asymptotic skewness in Birnbaum-Saunders nonlinear regression models

The family of distributions proposed by Birnbaum and Saunders (1969) can be used to model lifetime data and it is widely applicable to model failure times of fatiguing materials. We give a simple matrix formula of order n(-1/2), where n is the sample size, for the skewness of the distributions of the maximum likelihood estimates of the parameters in Birnbaum-Saunders nonlinear regression models, recently introduced by Lemonte and Cordeiro (2009). The formula is quite suitable for computer implementation, since it involves only simple operations on matrices and vectors, in order to obtain closed-form skewness in a wide range of nonlinear regression models. Empirical and real applications are analyzed and discussed. (C) 2010 Elsevier B.V. All rights reserved.

Estimation of Parameters in Random Effect Models with Incidence Matrix Uncertainty

Random effect models have been widely applied in many fields of research. However, models with uncertain design matrices for random effects have been little investigated before. In some applications with such problems, an expectation method has been used for simplicity. This method does not include the extra information of uncertainty in the design matrix is not included. The closed solution for this problem is generally difficult to attain. We therefore propose an two-step algorithm for estimating the parameters, especially the variance components in the model. The implementation is based on Monte Carlo approximation and a Newton-Raphson-based EM algorithm. As an example, a simulated genetics dataset was analyzed. The results showed that the proportion of the total variance explained by the random effects was accurately estimated, which was highly underestimated by the expectation method. By introducing heuristic search and optimization methods, the algorithm can possibly be developed to infer the 'model-based' best design matrix and the corresponding best estimates.

A critical examination of ethical decision making models

This paper critically examines both the need for, and the use of, ethical decision making models (EDMMs). This paper suggests that EDMMs focus on arriving at the correct decision but ignore the action required to implement it and are therefore incomplete. In most “accounting” circumstances, finding the right decision is not what is required. Rather, a model which provides both a sound decision and, appropriate implementation would be more useful. In trying to establish a new/different EDDM that provides for this it is argued that a biblical model exists which addresses both decision making and action. This paper aims to encourage accounting ethics education to move beyond determining the right decision and focus on taking the right action.

Concepts, models and analyses of electronic demolition of buildings

The demolition of building structures produces enormous amounts of waste materials. In most current demolition projects, a great number of demolished materials are directly sent to landfill after their primary usage due to the difficulties in finding their next usage immediately. At the same time, because of limited supply of second-hand materials, new and high quality materials are used in construction projects whose design standards can be fitted using the secondary or used materials. However, this is an inefficient method to reduce waste because off the flow nature of the current waste-exchange systems and the demolition procedure. The recent concept using deconstruction rather than destruction for demolishing a constructed facility fails to achieve widespread understanding or acceptance due to various practical limitations. In this paper, for the purpose of envisaging the deconstruction implementations in practice and promoting cascading usages of construction materials, the concept of electronic demolition (e-Demotion, eDemolition) is put forward for the first time. E-demolition is a virtual demolition approach by which the demolition information, progress and outputs are operated before the physical demolition. Furthermore, the authors set up the essential models to implement electronic demolition of buildings from the viewpoints of demolition progress, business, and information. Each model is demonstrated in accord with the conventional demolition practice and subject to the ideal deconstruction implementation. Following the electronic demolition of a real project, the physical demolition can be anticipated with a minimum of construction waste emission.

The conceptualisation of operational risk management models

Operational risk is evolving as a specialist field of risk management that must be practiced within all organisations, but currently has a particular relevance to banks. The Basel Committee on Banking Supervision has circulated a consultative paper which, if adopted by nation-state bank supervisors, will impose an operational risk capital charge on banks as part of a new Capital Accord. The definition of operational risk is wide-ranging and creates some unique issues related to the development of appropriate risk management models. This paper conceptualises two distinct operational risk management models; being a predictive model that will result in a known outcome upon its implementation, and a pre-emptive operational risk management model which prepares an organisation in the event that a future risk occurrence results in a disruption to critical business operations.

The conceptualisation of operational risk management models

Operational risk is evolving as a specialist field of risk management that must be practiced within all organisations, but currently has a particular relevance to banks. The Basel Committee on Banking Supervision has circulated a consultative paper which, if adopted by nation-state bank supervisors, will impose an operational risk capital charge on banks as part of a new Capital Accord. The definition of operational risk is wide-ranging and creates some unique issues related to the development of appropriate risk management models. This paper conceptualises two distinct operational risk management models; being a predictive model that will result in a known outcome upon its implementation, and a pre-emptive operational risk management model which prepares an organisation in the event that a future risk occurrence results in a disruption to critical business operations.

Standing on the shoulders of giants : Are ERP success factors relevant for EDRMS implementation?

Records management has been a central concern for organisations in both private and public sectors since the beginning of the 21st century. This new focus is due both to the introduction of laws, regulations and standards affecting corporate information management; and to the way records are changing from paper-based to “born-digital” and “made-digital”. The need for an effective automated system to manage records is now greater than ever, with Electronic Document and Records Management Systems (EDRMS) being the most likely solution. Despite their increasing popularity, however, successful uptake of such systems is not yet widespread and research into their implementation is still limited. This paper investigates the possibility of applying existing Enterprise Resource Planning (ERP) models to EDRMS by analysing the substantial body of literature on success factors for ERP implementation, both qualitatively and quantitatively; and then comparing these with the still relatively limited literature on EDRMS.

Implementation of clinical practice guidelines using simulation in education

Background: Underpinning the Department of Human Services (DHS) “Future directions for Victoria’s maternity services” strategy in Victoria, are the principles of achieving the right balance between primary level care and access to appropriate levels of medical care by making the best use of the complementary skills of midwives, GPs and obstetricians. Planning new models of care have exposed a need to upskill many clinicians in providing evidence based pregnancy care. A statewide education program conducts 1 day workshops to multidisciplinary forums in Victoria. The program content is developed with each service and simulation activities are incorporated in the workshop to provide a realistic environment for practising skills related to the implementation of clinical practice guidelines.

Method: Post workshop surveys are completed anonymously by participants using a five point Likert scale to evaluate their experiences in peer learning, the use of simulation, reflective practice and communication skills training. Open ended responses were analysed thematically.

Results: In 2007, 14 workshops were conducted with 254 clinicians attending. The survey response rate was 80%. Participants responded ‘strongly agree’ or ‘agree’ that the workshop: enhanced their ability to access current pregnancy care research and information 193/ 204(95%), challenged them to think more broadly 192/204(94%), provided an opportunity to reflect on their communication skills during the simulation actives 197/201 (96%) and provided a valuable opportunity for observing the communication skills of their peers 197/ 201(98%).

Conclusion: Providing opportunities for peer learning in pregnancy education is valuable and the use of simulation can play an important role in overcoming barriers to implementing guidelines.

The implementation of mobile technology in organizations : expanding individual use contexts

Mobile computing devices such as personal digital assistants, smart mobile phones, and other handheld computing devices hold much promise in terms of their organizational application. Many existing models of the individual acceptance and implementation of information technology in organizational contexts have been developed in the era of “at the office” computing such as MIS, office automation, groupware, and so forth. We conducted two in-depth case studies of the implementation of mobile technology in healthcare organizations. The studies highlight interrelated individual use contexts due to the mobility of the technology: the individual as employee, as professional, as private user, and as member of society. The cases show that influences emanating from these use contexts impacted on the individual adoption of the technology within the organization. While broad extra-organizational influences are incorporated in some existing individual technology adoption models, we show that it becomes relevant to accommodate these influences more specifically in research models of mobile computing in organizations. Based on the extant literature and the case study data we pave the way toward more comprehensive models of the adoption and implementation of mobile technologies in organizations.

Corporate intranet implementation : managing emergent technologies and organizational practices

This paper examines the adoption and development of intranets in large business organizations. The authors demonstrate that intranet technology introduces a host of new managerial and technical challenges and requires new approaches to IS development. Evidence from two European corporations indicates that the traditional division of labor and definition of work roles in IS development breaks down. The distinction between developers and users becomes increasingly blurred and new organizational roles and structures associated with intranets are emerging. However, ready-made organizational models for implementing and managing intranets do not exist and the two organizations in this study have followed two different approaches. One organization favors a “planned change” approach, emphasizing management control and careful planning. The other organization prefers an “improvisational” approach, emphasizing experimentation, innovation and local initiative.

Intellectual property, creativity and innovation : IP models and the political economy of developing Asia

In advanced capitalist societies, intellectual property laws protecting such subject matter as copyright and patents are justified by a combination of theories, which include the provision of economic incentives to foster creativity and innovation and the prevention of unfair competition. IP academics and policy makers have differing views about the appropriate balance between these objectives and public interest considerations such as health, education and the protection of the environment. These different views entered the policy debate in Asian developing countries in connection with an unprecedented introduction and expansion of IP laws over the last 25 years. This paper will use case studies of law reform from Asia, in particular Southeast Asia, to show that the policy considerations of governments in reforming their laws were often quite different from the standard rationale mentioned above. As much of the IP was, at least initially, held by foreigners and introduced to attract foreign investment, national development considerations were joined with the more commonly quoted objectives to promote the rights, creativity and innovation of individuals. Such national development objectives at times coincided and at other times collided with official explanations and received wisdom about the effects of stronger IP rights.

Especially in the early postcolonial period, copyright laws and other IP laws were frequently restricted or simply not implemented, if they conflicted with development policies in areas such as education or public health. Such policies were slowly changing in the wake of WTO-TRIPS and other international agreements. Nevertheless, the implementation and enforcement of the IP laws has been uneven. Specialised institutions such as courts and IP administering agencies compete with other branches of government and administration for limited funding and a rich repertoire of informal dispute settlement procedures has kept the number of court cases relatively low. In some countries, censorship laws have influenced freedom of expression and led to quite idiosyncratic interpretations of intellectual property laws. Governments often also retain a role in the assessment of licensing and technology transfer contracts. And while there are many programs to foster individual creativity, in most cases R & D activities are still largely taking place in government institutions and this has influenced the thinking about intellectual property rights and creativity in the context of employment.

The paper uses a few case studies to examine the implementation of IP laws in selected Asian developing countries to point to the quite different institutional setting for IP law reform in comparison to European or American models. It reaches some tentative conclusions as to the likely effects on creativity and innovation under these different circumstances.