An Introduction to Evidential Reasoning for Decision Making under Uncertainty: Bayesian and Belief Functions Perspectives

The main purpose of this article is to introduce the evidential reasoning approach, a research methodology, for decision making under uncertainty. Bayesian framework and Dempster-Shafer theory of belief functions are used to model uncertainties in the decision problem. We first introduce the basics of the DS theory and then discuss the evidential reasoning approach and related concepts. Next, we demonstrate how specific decision models can be developed from the basic evidential diagrams under the two frameworks. It is interesting to note that it is quite efficient to develop Bayesian models of the decision problems using the evidential reasoning approach compared to using the ladder diagram approach as used in the auditing literature. In addition, we compare the decision models developed in this paper with similar models developed in the literature

Representation of Interrelationships among Binary Variables under Dempster-Shafer Theory of Belief Functions

This is the peer reviewed version of the following article: Srivastava, R. P., L. Gao, and P. Gillett. " Representation of Interrelationships among Binary Variables under Dempster-Shafer Theory of Belief Functions" (pre-publication version), 2009, International Journal of Intelligent Systems, Volume 24 Issue 4, pp. 459 - 475, which has been published in final form at http://doi.org/10.1002/int.20347. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.This paper presents an algorithm for developing models under Dempster-Shafer theory of belief functions for categorical and 'uncertain' logical relationships among binary variables. We illustrate the use of the algorithm by developing belief-function representations of the following categorical relationships: 'AND', 'OR', 'Exclusive OR (EOR)' and 'Not Exclusive OR (NEOR)', and 'AND-NEOR' and of the following uncertain relationships: 'Discounted AND', 'Conditional OR', and 'Weighted Average'. Such representations are needed to fully model and analyze a problem with a network of interrelated variables under Dempster-Shafer theory of belief functions. In addition, we compare our belief-function representation of the 'Weighted Average' relationship with the 'Weighted Average' representation developed and used by Shenoy and Shenoy8. We find that Shenoy and Shenoy representation of the weighted average relationship is an approximation and yields significantly different values under certain conditions

Model Reka Bentuk Konseptual Operasian Storan Data Bagi Aplikasi Kepintaran Perniagaan

The development of business intelligence (BI) applications, involving of data sources, Data Warehouse (DW), Data Mart (DM) and Operational Data Store (ODS), imposes a major challenge to BI developers. This is mainly due to the lack of established models, guidelines and techniques in the development process as compared to system development in the discipline of software engineering. Furthermore, the present BI applications emphasize on the development of strategic information in contrast to operational and tactical. Therefore, the main aim of this study is to propose a conceptual design model for BI applications using ODS (CoDMODS). Through expert validation, the proposed conceptual design model that was developed by means of design science research approach, was found to satisfy nine quality model dimensions, which are, easy to understand, covers clear steps, is relevant and timeless, demonstrates flexibility, scalability, accuracy, completeness and consistency. Additionally, the two prototypes that were developed based on CoDMODS for water supply service (iUBIS) and telecommunication maintenance (iPMS) recorded a high usability average min value of 5.912 using Computer System Usability Questionnaire (CSUQ) instrument. The outcomes of this study, particularly the proposed model, contribute to the analysis and design method for the development of the operational and tactical information in BI applications. The model can be referred as guidelines by BI developers. Furthermore, the prototypes that were developed in the case studies can assist the organizations in using quality information for business operations

Assurance on XBRL Instance Document: A Conceptual Framework of Assertions

XBRL stands for extensible business reporting language. It is an XML based computer language for reporting business information. In December 2008, the United States Securities and Exchange Commission (US SEC) voted to require public filers to provide a supplemental exhibit of their financial statements (including footnotes) in XBRL, with the top approximately 500 public companies required to comply with this new requirement starting on June 15, 2009, and the phase-in of this requirement for the other filers to be completed on June 15, 2011. The file created using the XRBL language is called an XBRL instance document. Under this requirement, the filers are not required to obtain a third party assurance on the XBRL instance document. The main reason for not requiring a third party independent assurance of XBRL instance documents is to encourage filers to comply with the SEC requirement without incurring much added costs. In addition, to encourage the filers to comply with this requirement, the SEC is not holding filers legally liable of any errors in the filed XBRL instance documents so long as they look similar to the standard reports when viewed using the SEC viewer. Even though the SEC is not currently requiring a third party assurance of the XBRL instance documents of the SEC filings, it is in the best interest of the public that these documents be assured. Although there have been efforts by both the practitioners and academics to investigate issues involved in providing assurance on XBRL documents, these efforts have been focused on the specifics of the assurance process and the difficulties involved in it, and not on developing a framework of assertions. Even the American Institute of Certified Public Accountants recent publication SOP 09-1 provides only an illustrative list of management assertions for handling the XBRL-tagging engagements under the SSAEs as agreed-upon procedures without considering a framework. Without a conceptual framework, the assurance process for XBRL instance document would be ad hoc and inconsistent. This paper develops a set of assertions for providing assurance on XBRL instance documents similar to the management assertions for financial audits. Further, we discuss how such a framework would assist auditors in planning and evaluating such an engagement by collecting appropriate items of evidence pertaining to specific assertions to form an opinion whether the instance document is a true representation of the standard format (i.e., ASCII or HTML) document. We also discuss how the use of new technology would make the assurance process more effective and efficient

Corporate Sustainability Reporting: Investigation of Assurance Process, Assurance Characteristics and Assurance Frameworks Used

This dissertation is on assured sustainability reporting. It has three parts that are titled as follows: Part 1. Planning Assurance Services for Sustainability Reporting: An Analysis of Cost versus Assurance in Audit Evidence, Part 2. The Development of Worldwide Assured Sustainability reporting, and, Part 3. Assurance on Sustainability Reports: A Study of Factors Influencing the Selection of an Assurance Framework. Of the above, Part 1 is complete and ready for submission to a journal and Part 2 has been accepted for publication in Australian Accounting Review. Part 1 investigates providing assurance on sustainability reporting and demonstrates how an evidential reasoning framework can enhance providing such a service. It develops a framework based on the Dempster-Shafer theory of belief functions for the purpose of audit program planning and cost analysis. A sensitivity analysis is used to demonstrate the value of the model based on seven scenarios. The cost to perform an audit procedure is assumed to increase exponentially with the increase in the targeted level of assurance and audit procedures are assumed to exhibit inherent limitations as to the maximum level of assurance they can be expected to provide. Results demonstrate as follows: i. the importance of the assurance provider selecting audit procedures that directly relate to the highest level assertions, ii. the effects of discovering during the audit that certain audit tests are less diagnostic than anticipated, iii. the effects of obtaining mixed audit evidence, iv. the effects of obtaining strong evidence that implies that certain assertions are not fairly stated and v. the effects of planning to provide different levels of assurance across assertions Each of these findings demonstrates the value of utilizing a formal evidential reasoning and cost minimization approach in providing assurance on sustainability reports. Part 2 investigates the development of assured sustainability reports (SRs) during this century's first decade. More specifically, it presents basic descriptive data on a sample of 148 SRs published in 2006 and 2007 and contrasts this sample with the sample discussed in Mock, Strohm, and Swartz (MSS 2007). The prior study examined a sample of 130 assured SRs issued between 2002 and 2004. Both samples provide information about the nature of sustainability reports, allowing us to investigate important questions such as which countries and industries are more likely to have an assurance statement, what levels of assurance are provided, and what factors affect the level of assurance provided. In addition to providing descriptive data relative to the above questions, we run logistic regressions where the dependent variable is whether a Big4 firm provided the assurance, for both periods being considered. Some important differences are observed related to whether the assurance provided applies to both the quantitative and qualitative assertions made in the report (significantly negatively associated with Big4 in the 2002-2004 period, but not significant in 2006-2007), whether the report uses symbols to identify assured statements (significantly positively associated with Big4 in the 2002- 2004 period, but not significant in 2006-2007), and whether the procedures used are disclosed (not significant in 2002-2004, but significantly positively associated with Big4 in 2006-2007). Part 3 examines the factors that influence the assurance provider in the selection of an assurance framework for the purpose of assuring sustainability reports where assurance is voluntarily sought by the organization issuing the sustainability report. These frameworks are not generally accepted and no authority mandates these frameworks. Audit-firm specific, client-company specific and country level factors are considered as explanatory variables. Multi-level modeling is used for analysis since companies are nested within countries. Analysis suggests that the following country levels factors have significant impact on the selection of the type of assurance frameworks (i.e. international frameworks or regional frameworks): level of disclosure, market capitalization and the level of carbon dioxide emissions. Further, analysis suggests that two client company characteristics also have a significant impact: whether a company has foreign operations, and, the level of growth opportunities. One of the important ways of adding credibility to sustainability reports published by companies is obtaining assurance on them (Simnett, Vanstraelen and Chua 2009). Hence, the type of assurance framework used (International versus Regional) may indicate assurance provider preferences. Use of international frameworks (ISAE3000 and AA1000AS) may indicate a trend towards standardization of assurance frameworks and ease of comparison. On the other hand, use of regional assurance frameworks may indicate a possible country-of-origin effect. Factors that influence the selection of assurance frameworks and the type of assurance framework selected are important because it offers insights into trends and opportunities that shape the growing assurance market in the sustainability area. This could aid companies, assurance providers, standard setting bodies and investors respond to a changing environment in a meaningful way

A Research Platform for Artificial Neural Networks with Applications in Pediatric Epilepsy

This dissertation established a state-of-the-art programming tool for designing and training artificial neural networks (ANNs) and showed its applicability to brain research. The developed tool, called NeuralStudio, allows users without programming skills to conduct studies based on ANNs in a powerful and very user friendly interface. A series of unique features has been implemented in NeuralStudio, such as ROC analysis, cross-validation, network averaging, topology optimization, and optimization of the activation function’s slopes. It also included a Support Vector Machines module for comparison purposes. Once the tool was fully developed, it was applied to two studies in brain research. In the first study, the goal was to create and train an ANN to detect epileptic seizures from subdural EEG. This analysis involved extracting features from the spectral power in the gamma frequencies. In the second application, a unique method was devised to link EEG recordings to epileptic and non-epileptic subjects. The contribution of this method consisted of developing a descriptor matrix that can be used to represent any EEG file regarding its duration and the number of electrodes. The first study showed that the inter-electrode mean of the spectral power in the gamma frequencies and its duration above a specific threshold performs better than the other frequencies in seizure detection, exhibiting an accuracy of 95.90%, a sensitivity of 92.59%, and a specificity of 96.84%. The second study yielded that Hjorth’s parameter activity is sufficient to accurately relate EEG to epileptic and non-epileptic subjects. After testing, accuracy, sensitivity and specificity of the classifier were all above 0.9667. Statistical tests measured the superiority of activity at over 99.99 % certainty. It was demonstrated that 1) the spectral power in the gamma frequencies is highly effective in locating seizures from EEG and 2) activity can be used to link EEG recordings to epileptic and non-epileptic subjects. These two studies required high computational load and could be addressed thanks to NeuralStudio. From a medical perspective, both methods proved the merits of NeuralStudio in brain research applications. For its outstanding features, NeuralStudio has been recently awarded a patent (US patent No. 7502763)