Application of object-orientation to HDL-based designs

The increase in the scale of VLSI circuits over the last two decades has been of great importance to the development process. To cope with this ever­growing design complexity. new development techniques and methodologies have been researched and applied. The early 90's have witnessed the uptake of a new kind of design methodology based on Hardware Description Languages (HDL). This methodology has helped to master the possibilities inherent in our ability to manufacture ever-larger designs. However. while HDL based design methodology is sufficient to address today's standard ASIC sizes, it reaches its limits when considering tomorrow's design scales. Already. RISC processor chip descriptions can contain tens of thousands of HDLlines. Object-Oriented design methodology has recently had a considerable Impact in the software design community as it is tightly coupled with the handling of complex systems. Object-Orientation concentrates on data rather than functions since. throughout the design process. data are more stable than functions. Methodologies for both hardware and software have been introduced through the application of HDLs to hardware design. Common design constructs and principles that have proved successful in software language development should therefore be considered in order to assess their suitability for HDLs based designs. A new methodology was created to emphasise on encapsulation. abstraction and classification of designs. using standard VHDL constructs. This achieves higher levels of modelling along with an Improved reusability through design inheritance. The development of extended semantics for integrating Object-Orientation in the VHDL language is described. Comparisons are made between the modelling abilities of the proposed extension and other competing proposals. A UNIX based Object-Oriented to standard VHDL pre-processor is described along with translation techniques and their issues related to synthesis and simulation. This tool permitted validation of the new design methodology by application to existing design problems

An Empirical investigation into metrics for object-oriented software

Object-Oriented methods have increased in popularity over the last decade, and are now the norm for software development in many application areas. Many claims were made for the superiority of object-oriented methods over more traditional methods, and these claims have largely been accepted, or at least not questioned by the software community. Such was the motivation for this thesis. One way of capturing information about software is the use of software metrics. However, if we are to have faith in the information, we must be satisfied that these metrics do indeed tell us what we need to know. This is not easy when the software characteristics we are interested in are intangible and unable to be precisely defined. This thesis considers the attempts to measure software and to make predictions regarding maintainabilty and effort over the last three decades. It examines traditional software metrics and considers their failings in the light of the calls for better standards of validation in terms of measurement theory and empirical study. From this five lessons were derived. The relatively new area of metrics for object-oriented systems is examined to determine whether suggestions for improvement have been widely heeded. The thesis uses an industrial case study and an experiment to examine one feature of objectorientation, inheritance, and its effect on aspects of maintainability, namely number of defects and time to implement a change. The case study is also used to demonstrate that it is possible to obtain early, simple and useful local prediction systems for important attributes such as system size and defects, using readily available measures rather than attempting predefined and possibly time consuming metrics which may suffer from poor definition, invalidity or inability to predict or capture anything of real use. The thesis concludes that there is empirical evidence to suggest a hypothesis linking inheritance and increased incidence of defects and increased maintenance effort and that more empirical studies are needed in order to test the hypothesis. This suggests that we should treat claims regarding the benefits of object-orientation for maintenance with some caution. This thesis also concludes that with the ability to produce, with little effort, accurate local metrics, we have an acceptable substitute for the large predefined metrics suites with their attendant problems

Usability issues and design principles for visual programming languages

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Despite two decades of empirical studies focusing on programmers and the problems with programming, usability of textual programming languages is still hard to achieve. Its younger relation, visual programming languages (VPLs) also share the same problem of poor usability. This research explores and investigates the usability issues relating to VPLs in order to suggest a set of design principles that emphasise usability. The approach adopted focuses on issues arising from the interaction and communication between the human (programmers), the computer (user interface), and the program. Being exploratory in nature, this PhD reviews the literature as a starting point for stimulating and developing research questions and hypotheses that experimental studies were conducted to investigate. However, the literature alone cannot provide a fully comprehensive list of possible usability problems in VPLs so that design principles can be confidently recommended. A commercial VPL was, therefore, holistically evaluated and a comprehensive list of usability problems was obtained from the research. Six empirical studies employing both quantitative and qualitative methodology were undertaken as dictated by the nature of the research. Five of these were controlled experiments and one was qualitative-naturalistic. The experiments studied the effect of a programming paradigm and of representation of program flow on novices' performances. The results indicated superiority of control-flow programs in relation to data-flow programs; a control-flow preference among novices; and in addition that directional representation does not affect performance while traversal direction does - due to cognitive demands imposed upon programmers. Results of the qualitative study included a list of 145 usability problems and these were further categorised into ten problem areas. These findings were integrated with other analytical work based upon the review of the literature in a structured fashion to form a checklist and a set of design principles for VPLs that are empirically grounded and evaluated against existing research in the literature. Furthermore, an extended framework for Cognitive Dimensions of Notations is also discussed and proposed as an evaluation method for diagrammatic VPLs on the basis of the qualitative study. The above consists of the major findings and deliverables of this research. Nevertheless, there are several other findings identified on the basis of the substantial amount of data obtained in the series of experiments carried out, which have made a novel contribution to knowledge in the fields of Human-Computer Interaction, Psychology of Programming, and Visual Programming Languages

Contested Natures, Insecurities and Territorialities: The Aerial Eradication of Coca in Colombia

Until very recently, Colombia was the only country in the world that still permitted the eradication of illicit crops –primarily coca and to a lesser extent, opium poppies— through aerial fumigation. It was a controversial practice for a number of reasons, chiefly the damage caused to plants, animals, and people living in or near fumigated areas. A favored tactic in the U.S.-supported War on Drugs, aerial eradication actually contributed to the spread of illicit crops to increasingly remote areas of Colombia, such as the collectively titled lands of both indigenous and black communities. Concerns about the practice of aerial eradication, however, appeared completely disconnected from the positive framing of the policy and guidelines governing its implementation. Employing mixed methods, both ethnographic and cartographic, this dissertation examines how these contradictory discourses —aerial eradication explained by officials involved in its operation versus described locally by people living in or near fumigated areas— materialized in 2015, the last year the aerial eradication program was in operation. This study engages critical social science theory to deconstruct dominant conceptualizations of territoriality, geopolitics and environmental conservation, while at the same time proposing alternative understandings of those concepts grounded in local experiences. This research finds that aerial eradication authorities overstated the accuracy of aerial eradication operations by: 1) downplaying the incidence of pilots spraying legal crops, 2) invalidating local reports on the effects of aerial eradication, and 3) requiring technical evidence far beyond the means of poor rural Colombian farmers. Furthermore, in the specific context of the collectively titled black communities of the Pacific region, aerial eradication authorities did not respect the right to previous consultation per Indigenous and Tribal Peoples Convention 169. This dissertation concludes that that aerial eradication —justified by notions of security and environmental conservation that had little to do with black communities of the Pacific region— operated as a means of displacement. This displacement was literal in the sense that aerial eradication made life difficult for people to live in affected communities and figurative because local knowledge was pushed aside in favor of the external interpretations of the effects of this counternarcotics policy

Quality Assurance of Software Models - A Structured Quality Assurance Process Supported by a Flexible Tool Environment in the Eclipse Modeling Project

The paradigm of model-based software development (MBSD) has become more and more popular since it promises an increase in the efficiency and quality of software development. In this paradigm, software models play an increasingly important role and software quality and quality assurance consequently leads back to the quality and quality assurance of the involved models. The fundamental aim of this thesis is the definition of a structured syntax-oriented process for quality assurance of software models that can be adapted to project-specific and domain-specific needs. It is structured into two sub-processes: a process for the specification of project-specific model quality assurance techniques, and a process for applying them on concrete software models within a MBSD project. The approach concentrates on quality aspects to be checked on the abstract model syntax and is based on quality assurance techniques model metrics, smells, and refactorings well-known from literature. So far, these techniques are mostly considered in isolation only and therefore the proposed process integrates them in order to perform model quality assurance more systematically. Three example cases performing the process serve as proof-of-concept implementations and show its applicability, its flexibility, and hence its usefulness. Related to several issues concerning model quality assurance minor contributions of this thesis are (1) the definition of a quality model for model quality that consists of high-level quality attributes and low-level characteristics, (2) overviews on metrics, smells, and refactorings for UML class models including structured descriptions of each technique, and (3) an approach for composite model refactoring that concentrates on the specification of refactoring composition. Since manually reviewing models is time consuming and error prone, several tasks of the proposed process should consequently be automated. As a further main contribution, this thesis presents a flexible tool environment for model quality assurance which is based on the Eclipse Modeling Framework (EMF), a common open source technology in model-based software development. The tool set is part of the Eclipse Modeling Project (EMP) and belongs to the Eclipse incubation project EMF Refactor which is available under the Eclipse public license (EPL). The EMF Refactor framework supports both the model designer and the model reviewer by obtaining metrics reports, by checking for potential model deficiencies (called model smells) and by systematically restructuring models using refactorings. The functionality of EMF Refactor is integrated into standard tree-based EMF instance editors, graphical GMF-based editors as used by Papyrus UML, and textual editors provided by Xtext. Several experiments and studies show the suitability of the tools for supporting the techniques of the structured syntax-oriented model quality assurance process

Species boundaries in bats: a philosophical, morphometric, environmental, and phylogenetic analysis of the genera Anoura, Carollia and Sturnira

Thesis (Ph.D.)--Boston UniversitySpecies are central to evolutionary biology, systematics and taxonomy. However, their precise definition and diagnosis is not straightforward. Species may be purely nominal constructs of the human mind or they may be real entities. Part of the difficulty of defining and diagnosing species lies in the continuous nature of variation from the level of the individual to the population, subspecies and species. It is here where systematics and taxonomy become challenging and exciting tools for understanding life on the planet. For bats, most of the efforts to describe and differentiate species have been qualitative. This may have worked in earlier times, during the first efforts to describe and name species. But, more recently, our perspectives have become sharper and the shortcomings of the qualitative approach have become obvious. This thesis is a collection of published essays, submitted studies, and ongoing research into the boundaries of bat species. In each chapter, I stress that species are not ideas or categories in the mind, but are real entities, based on testable hypotheses about the distribution of character states within multiorganismal entities. Therefore, these hypotheses and distributions of character states should optimally be analyzed through the prism of statistical inference. The dynamics of size and shape in the genus Anoura are discussed in the context of the space occupied by the different species within the genus, with novel insights into the interpretation of the distribution of these species in morphospace. For boundaries in the genus Carollia, I reassess current taxonomical knowledge, analyze morphological variation in relation to the environment, and the statistical uncertainty of species discrimination. In the species-rich genus Sturnira, I analyze a large morphological dataset for several species from Ecuador, describe a new species (S. peria) synonymize an old one (S. luisi), and provide a new perspective on phylogenetic relationships and species boundaries

Slicing of Concurrent Programs and its Application to Information Flow Control

This thesis presents a practical technique for information flow control for concurrent programs with threads and shared-memory communication. The technique guarantees confidentiality of information with respect to a reasonable attacker model and utilizes program dependence graphs (PDGs), a language-independent representation of information flow in a program

Land tenure in rural lowland Myanmar: From historical perspectives to contemporary realities in the Dry zone and the Delta: Of lives of land Myanmar research series.

This study emerged out of an identified need to document social processes leading to land insecurity, and those leading to investment and sustainable use of lands by rural populations. Focusing on the Delta and Dry Zone, the main paddy producing regions of Myanmar, this analysis unravels the powers at play in shaping rural households’ relationship to land. From British colonization to the 2012 reforms, many issues have remained relatively unchanged with regards to local dynamics of landlessness, exclusion processes, local power plays, restrictions in farmers’ land rights and the State’s excessive focus on rice. In the midst of a fast evolving legal context, this work provides a typology of farmers and the landless and argues that more attention needs to be paid to understand the diversity of rural households and forms of landlessness