The uses of qualitative data in multimethodology:Developing causal loop diagrams during the coding process

In this research note we describe a method for exploring the creation of causal loop diagrams (CLDs) from the coding trees developed through a grounded theory approach and using computer aided qualitative data analysis software (CAQDAS). The theoretical background to the approach is multimethodology, in line with Minger’s description of paradigm crossing and is appropriately situated within the Appreciate and Analyse phases of PSM intervention. The practical use of this method has been explored and three case studies are presented from the domains of organisational change and entrepreneurial studies. The value of this method is twofold; (i) it has the potential to improve dynamic sensibility in the process of qualitative data analysis, and (ii) it can provide a more rigorous approach to developing CLDs in the formation stage of system dynamics modelling. We propose that the further development of this method requires its implementation within CAQDAS packages so that CLD creation, as a precursor to full system dynamics modelling, is contemporaneous with coding and consistent with a bridging strategy of paradigm crossing

System testing of a production Ada (trademark) project: The GRODY study

The use of the Ada language and design methodologies that utilize its features has a strong impact on all phases of the software development project lifecycle. At the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC), the Software Engineering Laboratory (SEL) conducted an experiment in parallel development of two flight dynamics systems in FORTRAN and Ada. The teams found some qualitative differences between the system test phases of the two projects. Although planning for system testing and conducting of tests were not generally affected by the use of Ada, the solving of problems found in system testing was generally facilitated by Ada constructs and design methodology. Most problems found in system testing were not due to difficulty with the language or methodology but to lack of experience with the application

Numerical study of asymmetric keel hydrodynamic performance through advanced CFD

The hydrodynamics of an asymmetric IACC yacht keel at angle of yaw are presented using simulations performed by advanced computational fluid dynamics using state-of-the-art software. The aim of the paper is to continue working on the improvement of numerical viscous flow predictions for high-performance yachts using Large Eddy Simulation and Detached Eddy Simulation on unstructured grids. Quantitative comparisons of global forces acting on the keel and wake survey are carried out. Qualitative comparisons include flow visualisation, unsteady and separated flow and other features. Star-CCM+ and the trimmed cell method give better forces and wake prediction compared to the unstructured mesh of ANSYS Fluent. Both solvers give good flow visualisation near and far field of the keel

Stability analysis of mathematical models of infectious disease

Dynamics of infectious disease in vivo is described by coupled differential equations. Stability analysis of the complicated systems is difficult without computer calculation, while stability analysis is, in general, important to investigate qualitative behaviour of models. Liu analyzes stability of systems describing HIV dynamics in vivo with a symbolic calculation software. The same method is used for stability analysis of a mathematical model of malaria

Transient Simulation of Chemical Looping Combustion using Computational Fluid Dynamics

Packed bed chemical looping combustion (CLC) reactors are a safer and more sustainable method for creating energy from the combustion of hydrocarbons. This project presents a transient simulation of a CLC reactor using the computational fluid dynamics (CFD) software package Fluent 6.3. Results were obtained for the reduction and oxidation phases of the process, illustrating the expected qualitative trends. This project concludes that CFD software can be effectively used to simulate transient chemical reactions

Identifying parameter regions for multistationarity

Mathematical modelling has become an established tool for studying the dynamics of biological systems. Current applications range from building models that reproduce quantitative data to identifying systems with predefined qualitative features, such as switching behaviour, bistability or oscillations. Mathematically, the latter question amounts to identifying parameter values associated with a given qualitative feature. We introduce a procedure to partition the parameter space of a parameterized system of ordinary differential equations into regions for which the system has a unique or multiple equilibria. The procedure is based on the computation of the Brouwer degree, and it creates a multivariate polynomial with parameter depending coefficients. The signs of the coefficients determine parameter regions with and without multistationarity. A particular strength of the procedure is the avoidance of numerical analysis and parameter sampling. The procedure consists of a number of steps. Each of these steps might be addressed algorithmically using various computer programs and available software, or manually. We demonstrate our procedure on several models of gene transcription and cell signalling, and show that in many cases we obtain a complete partitioning of the parameter space with respect to multistationarity.Comment: In this version the paper has been substantially rewritten and reorganised. Theorem 1 has been reformulated and Corollary 1 adde

Parallel Anisotropic Unstructured Grid Adaptation

Computational Fluid Dynamics (CFD) has become critical to the design and analysis of aerospace vehicles. Parallel grid adaptation that resolves multiple scales with anisotropy is identified as one of the challenges in the CFD Vision 2030 Study to increase the capacity and capability of CFD simulation. The Study also cautions that computer architectures are undergoing a radical change and dramatic increases in algorithm concurrency will be required to exploit full performance. This paper reviews four different methods to parallel anisotropic grid generation. They cover both ends of the spectrum: (i) using existing state-of-the-art software optimized for a single core and modifying it for parallel platforms and (ii) designing and implementing scalable software with incomplete, but rapidly maturating functionality. A brief overview for each grid adaptation system is presented in the context of a telescopic approach for multilevel concurrency. These methods employ different approaches to enable parallel execution, which provides a unique opportunity to illustrate the relative behavior of each approach. Qualitative and quantitative metric evaluations are used to draw lessons for future developments in this critical area for parallel CFD simulation

An Integrated Decision Support Toolbox (DST) for the Management of Mountain Protected Areas

New tools and methodologies are required in systemic planning and management of mountain protected areas. Among others we propose here a decision support toolbox (DST) conceived as an integrated collection of both soft and hard system methodologies, consisting of participatory and computer-based modules to provide a set of integrated, self-contained tools and approaches to support decision-making processes in the management of mountain protected areas. The Sagarmatha National Park and Buffer Zone (SNPBZ) in Nepal was taken as a pilot case. A number of participatory exercises such as participatory 3-dimensional modeling, scenario planning, and qualitative modeling were carried out to understand social-ecological processes and generate a systemic view over space and time. The qualitative models were then converted into computer-based system dynamics models. The design and development of DST software were carried out with an incremental and modular approach. This process involved stakeholder analysis and decision-making processes through a series of consultations. The software was developed with the main modules including scenario analysis, spatial analysis, and knowledge base. The scenario analysis module runs system dynamics models built in Simile software and provides functions to link them with spatial data for model inputs and outputs. The spatial analysis module provides the basic geographic information system functions to explore, edit, analyze, and visualize spatial information. The knowledge base module was developed as a metadata management system for different categories of information such as spatial data, bibliography, research data, and models. The development of DST software, especially system dynamics modeling and its linkage with spatial components, provided an important methodological approach for spatial and temporal integration. Furthermore, training and interactions with park managers and concerned stakeholders showed that DST is a useful platform for integrating data and information and better understanding ecosystem behavior as a basis for management decisions

Open Source Software in Health Information Systems: Opportunities and Challenges

The paper presents results of a study seeking to identify constraining and motivating factors associated with the adoption and use of Free Open Source Software to computerise health Information Systems in a developing country. The study approach is interpretive research to case study with a triangulation of several qualitative data collection methods such as interviews, group discussions and document analysis. The findings indicate that using open source software has advantages and disadvantages. The advantages are low entry cost to adopting software, possibilities of software localization, avoiding being hostage of proprietary software and foster knowledge acquisition among software developers. The disadvantages are the need for constant internet access, high switching costs, and lack of human resources especially IT professionals to maintain the software since users get more rights in using and maintaining the system. The study concludes that because of the dynamics in health information systems, open source is appropriate