The evolution of complete software systems

This thesis tackles a series of problems related to the evolution of completesoftware systems both in terms of the underlying Genetic Programmingsystem and the application of that system. A new representation is presented that addresses some of the issues withother Genetic Program representations while keeping their advantages. Thiscombines the easy reproduction of the linear representation with the inheritablecharacteristics of the tree representation by using fixed-length blocks ofgenes representing single program statements. This means that each block ofgenes will always map to the same statement in the parent and child unless itis mutated, irrespective of changes to the surrounding blocks. This methodis compared to the variable length gene blocks used by other representationswith a clear improvement in the similarity between parent and child. Traditionally, fitness functions have either been created as a selection ofsample inputs with known outputs or as hand-crafted evaluation functions. Anew method of creating fitness evaluation functions is introduced that takesthe formal specification of the desired function as its basis. This approachensures that the fitness function is complete and concise. The fitness functionscreated from formal specifications are compared to simple input/outputpairs and the results show that the functions created from formal specificationsperform significantly better. A set of list evaluation and manipulation functions was evolved as anapplication of the new Genetic Program components. These functions havethe common feature that they all need to be 100% correct to be useful. Traditional Genetic Programming problems have mainly been optimizationor approximation problems. The list results are good but do highlight theproblem of scalability in that more complex functions lead to a dramaticincrease in the required evolution time. Finally, the evolution of graphical user interfaces is addressed. The representationfor the user interfaces is based on the new representation forprograms. In this case each gene block represents a component of the userinterface. The fitness of the interface is determined by comparing it to a seriesof constraints, which specify the layout, style and functionality requirements. A selection of web-based and desktop-based user interfaces were evolved. With these new approaches to Genetic Programming, the evolution ofcomplete software systems is now a realistic goal.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A comparison of older and younger offenders with delusional jealousy

We sought to determine whether or not there were differences in medical, criminological and legal factors between older and younger offenders with diagnoses of delusional jealousy by undertaking a retrospective case-file search of Australian legal databases. Our results demonstrate that older offenders were more likely to have comorbid dementia whereas younger offenders were more likely to have comorbid substance use and chronic psychotic conditions. A history of domestic violence frequently predated the index offence but we were unable to determine if this was due to psychosis or a pre-existing tendency for violence. Despite a common diagnosis, the older offenders were more likely to be made forensic patients rather than sentenced prisoners when compared with the younger offenders. Consequently, different factors might mediate the pathway to violence in older and younger people suffering from delusional jealousy and could be additional targets for clinical intervention

An improved representation for evolving programs

A representation has been developed that addresses some of the issues with other Genetic Program representations while maintaining their advantages. This combines the easy reproduction of the linear representation with the inherita- ble characteristics of the tree representation by using fixed-length blocks of genes representing single program statements. This means that each block of genes will always map to the same statement in the parent and child unless it is mutated, irrespective of changes to the surrounding blocks. This method is compared to the variable length gene blocks used by other representations with a clear improvement in the similarity between parent and child. In addition, a set of list evaluation and manipulation functions was evolved as an application of the new Genetic Program components. These functions have the common feature that they all need to be 100% correct to be useful. Traditional Genetic Programming problems have mainly been optimization or approximation problems. The list results are good but do highlight the problem of scalability in that more complex functions lead to a dramatic increase in the required evolution time

Comparing content-filter techniques for stopping spam

There are many new theoretical techniques for detecting spam e-mail based upon the message contents. Although Bayesian methods are the most wellknown, there are other approaches for classifying information. This paper establishes some criteria for measuring spam filter effectiveness and compares the Boosting and Support Vector Machine approaches with some well-known existing filter software. It also examines ways of transforming e-mail messages into a form which is more readily processable by such algorithms

Evolving readable Perl

A program is informally deemed readable, for the purpose of this experiment, if it is easy for a person to follow the steps that the program takes to solve the problem. In this experiment, readability is achieved by constraining the available syntax for generating solutions. The Genetic Programming (GP) system created uses the target language Perl because it is an interpreted, untyped, robust procedural language which has good error handling and recovery

Evolving Perl

A list of requirements for a genetic programming representation is put forward and a representation separating the genotype and phenotype with a linear genome is presented. The target language for the genetic program is Perl. The mapping process, between the genotype and phenotype, converts blocks of four genes into program statements. This process is context-free and therefore provides inheritable characteristics. The representation is tested by evolving a selection of list evaluation and manipulation functions which are all evolved from the same language subset, with good results

Evolving the user interface

A method is presented for evolving Graphical User Interfaces using Genetic Algorithms. The fitness evaluation is based on a series of constraints, which must be met by the user interface. Examples are used to demonstrate the use of positional, style and functionality constraints and the final example shows the evolution of a complete (although simple) software application

Packet transmission optimisation using Genetic Algorithms

A Genetic Algorithm (ga) is used to optimise the parameters for a sequence of packets sent over the Internet. Only the parameters that a client machine can change are used and the fitness is based on the delay time returned by the Traceroute program. The ga performance is compared to a fixed packet size with no priority used to assess the status of the network. The ga generally performed to the same level as the control settings but in some cases significant improvements were made

Accelerated aging in people experiencing homelessness: A rapid review of frailty prevalence and determinants

Introduction: Older people experiencing homelessness (PEH) are a rapidly growing population at risk of accelerated aging and the early onset of geriatric conditions. One construct that shows promise in predicting age-related decline is frailty. Better understanding the rates and causes of frailty in PEH may improve understanding of its antecedents, thereby facilitating more targeted health and aged care service interventions. The aim of this study was to conduct a rapid review on the prevalence and determinants of frailty in adult PEH. Methods: We conducted a rapid review of primary research papers studying PEH and frailty or frailty-related concepts. Results: Fourteen studies were included, which indicate that frailty presents earlier and at higher rates in PEH than community-dwelling cohorts. A notable difficulty for many aging PEH was early-onset cognitive impairment which was associated with a range of negative functional outcomes. Another recurrent theme was the negative impact that drug and alcohol use and dependence can have on the health of PEH. Further, psychosocial and structural determinants such as loneliness, living in an impoverished neighborhood and being female had statistically significant associations with frailty and functional decline in PEH. Discussion and implications: PEH in their 40s and 50s can be frail and experience geriatric conditions, including cognitive impairment. Factors that have important relationships to frailty and functional decline in PEH include cognitive deficits, drug and alcohol dependence and loneliness, as well as upstream determinants such as gender and ethnicity. More targeted data and research on these factors, including cohort studies to better investigate their potentially causal effects, is important for researchers and practitioners assessing and treating frailty in PEH, particularly those interested in early intervention and prevention. Prospero registration ID: CRD42022292549