A Windows program for airfoil design using B-splines

The objective of this thesis has been threefold. First, the formulation of splines has been studied and their development into a computer algorithm has been implemented. Splines represent a powerful concept in computer modeling and geometric representation, for, as parametric curves, they provide a compact way to store the information defining a curve or surface. B-splines have been exclusively used in this thesis, although other types of splines exist. The second goal of this thesis was to learn and utilize C++ as a programming tool in the demonstration of B-spline techniques. C++ was chosen because it is object-oriented, and because it is the chosen language of the Microsoft Windows PC platform. Many languages are object-oriented, but C++ was chosen to make use of its libraries to build standard Windows interfaces and objects. The third piece of this thesis is an effort to explore the fundamentals of inter-language communications. Many old scientific codes are already written in older languages like FORTRAN, so it is advantageous to re-use those codes where possible. Digital Visual FORTRAN, a module of the Microsoft Visual Studio, has provided a powerful tool in their integration of multiple programming languages for Windows applications. Using Visual Studio, it is possible to re-use existing FORTRAN code and envelop it in a C interface using a dynamic link library (DLL) file. This thesis uses a C++ application for defining any typical airfoil using B-splines. The software package calls XFOIL, a code written in FORTRAN to evaluate the aerodynamic characteristics of those airfoils. Further, those characteristics have been compared to those of the original geometry to evaluate the interpolation process used by the splines

Algebraic geometric methods for the stabilizability and reliability of multivariable and of multimode systems

The extent to which feedback can alter the dynamic characteristics (e.g., instability, oscillations) of a control system, possibly operating in one or more modes (e.g., failure versus nonfailure of one or more components) is examined

GIS Application to Support Land Administration Services in Ghana: Institutional Factors and Software Developments

In June 1999, the Ghanaian Government launched a new land policy document that sought to address some fundamental problems associated with land administration and management in the country. The document identified the weak land administration system as a particular problem and recommended the introduction of computer-aided information systems in the ‘lands sector’. In 2001, the Government made further proposals to prepare and implement a Land Administration Programme (LAP) to provide a better platform for evolving an efficient land administration that would translate the ‘National Land Policy’ into action. Thus, an up-to-date land information system (LIS), supporting efficient management of land records, is to be constructed, which provides a context for the research reported in this paper. We document two aspects of our research on the adoption of GIS by the Lands Commission Secretariat (LCS) which form part of a pilot project in GIS diffusion. Part one of the paper mainly outlines the empirical results arising from fieldwork undertaken during 2001 to determine the information and GIS requirements of the LCS in relation to their routine administrative processes and to identify the critical factors that are required to ensure that any new GIS applications are successfully embraced. Part two explains the prototype software system developed using ArcView 3.2 and Access that provides the LCS with a means to automate some of the routine administrative tasks that they are required to fulfil. The software has been modified and upgraded following an initial evaluation by LCS employees also conducted as part of the fieldwork in Accra

Unified Framework for Finite Element Assembly

At the heart of any finite element simulation is the assembly of matrices and vectors from discrete variational forms. We propose a general interface between problem-specific and general-purpose components of finite element programs. This interface is called Unified Form-assembly Code (UFC). A wide range of finite element problems is covered, including mixed finite elements and discontinuous Galerkin methods. We discuss how the UFC interface enables implementations of variational form evaluation to be independent of mesh and linear algebra components. UFC does not depend on any external libraries, and is released into the public domain

Reactive Semantic Planning in Unexplored Semantic Environments Using Deep Perceptual Feedback

This paper presents a reactive planning system that enriches the topological representation of an environment with a tightly integrated semantic representation, achieved by incorporating and exploiting advances in deep perceptual learning and probabilistic semantic reasoning. Our architecture combines object detection with semantic SLAM, affording robust, reactive logical as well as geometric planning in unexplored environments. Moreover, by incorporating a human mesh estimation algorithm, our system is capable of reacting and responding in real time to semantically labeled human motions and gestures. New formal results allow tracking of suitably non-adversarial moving targets, while maintaining the same collision avoidance guarantees. We suggest the empirical utility of the proposed control architecture with a numerical study including comparisons with a state-of-the-art dynamic replanning algorithm, and physical implementation on both a wheeled and legged platform in different settings with both geometric and semantic goals. For more information: Kod*la