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Usf Jamovi Tutorial Project: Open Education Resource, Aline Hitti, Saera Khan
Usf Jamovi Tutorial Project: Open Education Resource, Aline Hitti, Saera Khan
USF OER Faculty Grant
Jamovi is an open source free software that USF staff, faculty and student can download to carry out any statistical analyses. The current report summarizes the progress made on an Open Education Resource Grant funded project, which aimed to created Jamovi tutorials. In this report, student feedback and faculty reaction are summarized after one semester of using the tutorials created.
Gpusvcalibration: A R Package For Fast Stochastic Volatility Model Calibration Using Gpus, Matthew Dixon, Sabbir Ahmed Khan, Mohammad Zubair
Gpusvcalibration: A R Package For Fast Stochastic Volatility Model Calibration Using Gpus, Matthew Dixon, Sabbir Ahmed Khan, Mohammad Zubair
Business Analytics and Information Systems
In this paper we describe the gpusvcalibration R package for accelerating stochastic volatility model calibration on GPUs. The package is designed for use with existing CRAN packages for optimization such as DEOptim and nloptr. Stochastic volatility models are used extensively across the capital markets for pricing and risk management of exchange traded financial options. However, there are many challenges to calibration, including comparative assessment of the robustness of different models and optimization routines. For example, we observe that when fitted to sub-minute level midmarket quotes, models require frequent calibration every few minutes and the quality of the fit is routine …
Detecting Mobility Patterns In Mobile Phone Data From The Ivory Coast, Matthew Dixon, Spencer P. Aiello, Funmi Fapohunda, William Goldstein
Detecting Mobility Patterns In Mobile Phone Data From The Ivory Coast, Matthew Dixon, Spencer P. Aiello, Funmi Fapohunda, William Goldstein
Business Analytics and Information Systems
This paper investigates the Data for Development (D4D) challenge [3], an open challenge set by the French mobile phone company, Orange, who have provided anonymized records of their customers in the Ivory Coast. This data spans a 5 month (150 day) horizon spread across 4 different sets containing antenna-to-antenna traffic, trace data for 50,000 customers at varying spatial resolution, and social graphs for 5,000 customers. By leveraging cloud-based and open-source analytics infrastructure to (1) merge the D4D datasets with Geographic Information System (GIS) data and (2) apply data mining algorithms, this paper presents a number of techniques for detecting mobility …
Error Control Of Iterative Linear Solvers For Integrated Groundwater Models, Matthew Dixon, Z Bai, C F. Brush, F I. Chung, E C. Dogrul, T M. Kadir
Error Control Of Iterative Linear Solvers For Integrated Groundwater Models, Matthew Dixon, Z Bai, C F. Brush, F I. Chung, E C. Dogrul, T M. Kadir
Business Analytics and Information Systems
An open problem that arises when using modern iterative linear solvers, such as the preconditioned conjugate gradient method or Generalized Minimum RESidual (GMRES) method, is how to choose the residual tolerance in the linear solver to be consistent with the tolerance on the solution error. This problem is especially acute for integrated groundwater models, which are implicitly coupled to another model, such as surface water models, and resolve both multiple scales of flow and temporal interaction terms, giving rise to linear systems with variable scaling. This article uses the theory of “forward error bound estimation” to explain the correspondence between …
Towards Evaluating The Quality Of A Spreadsheet: The Case Of The Analytical Spreadsheet Model, Thomas A. Grossman Jr., Vijay Mehrotra, J Sander
Towards Evaluating The Quality Of A Spreadsheet: The Case Of The Analytical Spreadsheet Model, Thomas A. Grossman Jr., Vijay Mehrotra, J Sander
Business Analytics and Information Systems
We consider the challenge of creating guidelines to evaluate the quality of a spreadsheet model. We suggest four principles. First, state the domain—the spreadsheets to which the guidelines apply. Second, distinguish between the process by which a spreadsheet is constructed from the resulting spreadsheet artifact. Third, guidelines should be written in terms of the artifact, independent of the process. Fourth, the meaning of “quality” must be defined. We illustrate these principles with an example. We define the domain of “analytical spreadsheet models”, which are used in business, finance, engineering, and science. We propose for discussion a framework and terminology for …
Spreadsheets Grow Up: Three Spreadsheet Engineering Methodologies For Large Financial Planning Models, Thomas A. Grossman Jr., O Ozluk
Spreadsheets Grow Up: Three Spreadsheet Engineering Methodologies For Large Financial Planning Models, Thomas A. Grossman Jr., O Ozluk
Business Analytics and Information Systems
Many large financial planning models are written in a spreadsheet programming language (usually Microsoft Excel) and deployed as a spreadsheet application. Three groups, FAST Alliance, Operis Group, and BPM Analytics (under the name “Spreadsheet Standards Review Board”) have independently promulgated standardized processes for efficiently building such models. These spreadsheet engineering methodologies provide detailed guidance on design, construction process, and quality control. We summarize and compare these methodologies. They share many design practices, and standardized, mechanistic procedures to construct spreadsheets. We learned that a written book or standards document is by itself insufficient to understand a methodology. These methodologies represent a …
The Lookup Technique To Replace Nested-If Formulas In Spreadsheet Programming, Thomas A. Grossman Jr., O Ozluk, J Gustavson
The Lookup Technique To Replace Nested-If Formulas In Spreadsheet Programming, Thomas A. Grossman Jr., O Ozluk, J Gustavson
Business Analytics and Information Systems
Spreadsheet programmers often implement contingent logic using a nested-IF formula even though this technique is difficult to test and audit and is believed to be risky. We interpret the programming of contingent logic in spreadsheets in the context of traditional computer programming. We investigate the “lookup technique” as an alternative to nested-IF formulas, describe its benefits for testing and auditing, and define its limitations. The lookup technique employs four distinct principles: 1) make logical tests visible; 2) make outcomes visible; 3) make logical structure visible; and 4) replace a multi-function nested-IF formula with a single-function lookup formula. It can be …
Testing Diffusion Processes For Non-Stationarity, Jeff Hamrick, Murad S. Taqqu
Testing Diffusion Processes For Non-Stationarity, Jeff Hamrick, Murad S. Taqqu
Master of Science in Analytics (MSAN) Faculty Research
Financial data are often assumed to be generated by diffusions. Using recent results of Fan et al. (J Am Stat Assoc, 102:618–631, 2007; J Financ Econometer, 5:321–357, 2007) and a multiple comparisons procedure created by Benjamini and Hochberg (J R Stat Soc Ser B, 59:289–300, 1995), we develop a test for non-stationarity of a one-dimensional diffusion based on the time inhomogeneity of the diffusion function. The procedure uses a single sample path of the diffusion and involves two estimators, one temporal and one spatial. We first apply the test to simulated data generated from a variety of one-dimensional diffusions. We …
A Primer On Spreadsheet Analytics, Thomas A. Grossman Jr.
A Primer On Spreadsheet Analytics, Thomas A. Grossman Jr.
Business Analytics and Information Systems
This paper provides guidance to an analyst who wants to extract insight from a spreadsheet model. It discusses the terminology of spreadsheet analytics, how to prepare a spreadsheet model for analysis, and a hierarchy of analytical techniques. These techniques include sensitivity analysis, tornado charts, and backsolving (or goal-seeking). This paper presents native-Excel approaches for automating these techniques, and discusses add-ins that are even more efficient. Spreadsheet optimization and spreadsheet Monte Carlo simulation are briefly discussed. The paper concludes by calling for empirical research, and describing desired features spreadsheet sensitivity analysis and spreadsheet optimization add-ins.
Source Code Protection For Applications Written In Microsoft Excel And Google Spreadsheet, Thomas A. Grossman Jr.
Source Code Protection For Applications Written In Microsoft Excel And Google Spreadsheet, Thomas A. Grossman Jr.
Business Analytics and Information Systems
Spreadsheets are used to develop application software that is distributed to users. Unfortunately, the users often have the ability to change the programming statements (“source code”) of the spreadsheet application. This causes a host of problems. By critically examining the suitability of spreadsheet computer programming languages for application development, six “application development features” are identified, with source code protection being the most important. We investigate the status of these features and discuss how they might be implemented in the dominant Microsoft Excel spreadsheet and in the new Google Spreadsheet. Although Google Spreadsheet currently provides no source code control, its web-centric …
A Paradigm For Spreadsheet Engineering Methodologies, Thomas A. Grossman Jr., O Ozluk
A Paradigm For Spreadsheet Engineering Methodologies, Thomas A. Grossman Jr., O Ozluk
Business Analytics and Information Systems
Spreadsheet engineering methodologies are diverse and sometimes contradictory. It is difficult for spreadsheet developers to identify a spreadsheet engineering methodology that is appropriate for their class of spreadsheet, with its unique combination of goals, type of problem, and available time and resources. There is a lack of well-organized, proven methodologies with known costs and benefits for well-defined spreadsheet classes. It is difficult to compare and critically evaluate methodologies. We present a paradigm for organizing and interpreting spreadsheet engineering recommendations. It systematically addresses the myriad choices made when developing a spreadsheet, and explicitly considers resource constraints and other development parameters. This …
Accuracy In Spreadsheet Modelling Systems, Thomas A. Grossman Jr.
Accuracy In Spreadsheet Modelling Systems, Thomas A. Grossman Jr.
Business Analytics and Information Systems
Accuracy in spreadsheet modelling systems can be reduced due to difficulties with the inputs, the model itself, or the spreadsheet implementation of the model. When the "true" outputs from the system are unknowable, accuracy is evaluated subjectively. Less than perfect accuracy can be acceptable depending on the purpose of the model, problems with inputs, or resource constraints. Users build modelling systems iteratively, and choose to allocate limited resources to the inputs, the model, the spreadsheet implementation, and to employing the system for business analysis. When making these choices, users can suffer from expectation bias and diagnosis bias. Existing research results …
Research Strategy And Scoping Survey On Spreadsheet Practices, Thomas A. Grossman Jr., O Ozluk
Research Strategy And Scoping Survey On Spreadsheet Practices, Thomas A. Grossman Jr., O Ozluk
Business Analytics and Information Systems
We propose a research strategy for creating and deploying prescriptive recommendations for spreadsheet practice. Empirical data on usage can be used to create a taxonomy of spreadsheet classes. Within each class, existing practices and ideal practices can he combined into proposed best practices for deployment. As a first step we propose a scoping survey to gather non-anecdotal data on spreadsheet usage. The scoping survey will interview people who develop spreadsheets. We will investigate the determinants of spreadsheet importance, identify current industry practices, and document existing standards for creation and use of spreadsheets. The survey will provide insight into user attributes, …
Spreadsheet Engineering: A Research Framework, Thomas A. Grossman Jr.
Spreadsheet Engineering: A Research Framework, Thomas A. Grossman Jr.
Business Analytics and Information Systems
Spreadsheet engineering adapts the lessons of software engineering to spreadsheets, providing eight principles as a framework for organizing spreadsheet programming recommendations. Spreadsheets raise issues inadequately addressed by software engineering. Spreadsheets are a powerful modeling language, allowing strategic rapid model change, and enabling exploratory modeling. Spreadsheets users learn slowly with experience because they focus on the problem domain not programming. The heterogeneity of spreadsheet users requires a taxonomy to guide recommendations. Deployment of best practices is difficult and merits research.