Database rules and time: some proposed extensions to the SQL standard

The subject of this thesis is the incorporation of temporal semantics into database rules and how the resultant syntax might be reconciled with the evolving SQL standard. In particular, it explores time-driven rules and the time-relationship between triggering events and associated actions. A review of the key research results in the area of database rules and the syntax developed for the major prototype implementations is conducted, and a working syntax , free of any limitations within the SQL standard, developed. Next, an operational definition is evolved through the application of this working syntax to two sample domains rich in 'temporal rules'. In each case a graphical representation of the domain is presented using an adapted object-oriented modelling technique followed by a mapping into the working temporal syntax. Attention is then turned to the SQL-92 standard and its future successor SQL3. An assessment is made of their implications for the working syntax developed in the earlier chapters - with particular reference to the specification of time and the use of database triggers. When an attempt was made to re-cast the working syntax into SQL, a satisfactory mapping, which succeeded in preserving the semantics of the original, could not be achieved. Support for time-based triggers; cyclic operations; delayed actions and rule lifetimes necessitated the development of appropriate modifications to the basic SQL3 draft syntax. The proposed extensions capture all of the semantics required for the specification of time-based rules. The example applications indicated that an extended SQLcompliant language approach allied to a sound objectoriented modelling formalism had a broad applicability. Furthermore, it was apparent that the addition of a temporal dimension to rule actions was a key enabling factor in increasing their semantic power

Numerical aerodynamic simulation facility feasibility study

There were three major issues examined in the feasibility study. First, the ability of the proposed system architecture to support the anticipated workload was evaluated. Second, the throughput of the computational engine (the flow model processor) was studied using real application programs. Third, the availability reliability, and maintainability of the system were modeled. The evaluations were based on the baseline systems. The results show that the implementation of the Numerical Aerodynamic Simulation Facility, in the form considered, would indeed be a feasible project with an acceptable level of risk. The technology required (both hardware and software) either already exists or, in the case of a few parts, is expected to be announced this year. Facets of the work described include the hardware configuration, software, user language, and fault tolerance

Proceedings of the ACM SIGPLAN Workshop on Approaches and Applications of Inductive Programming (AAIP 2009)

Inductive programming is concerned with the automated construction of declarative, often functional, recursive programs from incomplete specifications such as input/output examples. The inferred program must be correct with respect to the provided examples in a generalising sense: it should be neither equivalent to them, nor inconsistent. Inductive programming algorithms are guided explicitly or implicitly by a language bias (the class of programs that can be induced) and a search bias (determining which generalised program is constructed first). Induction strategies are either generate-and-test or example-driven. In generate-and-test approaches, hypotheses about candidate programs are generated independently from the given specifications. Program candidates are tested against the given specification and one or more of the best evaluated candidates are developed further. In analytical approaches, candidate programs are constructed in an example-driven way. While generate-and-test approaches can -- in principle -- construct any kind of program, analytical approaches have a more limited scope. On the other hand, efficiency of induction is much higher in analytical approaches. Inductive programming is still mainly a topic of basic research, exploring how the intellectual ability of humans to infer generalised recursive procedures from incomplete evidence can be captured in the form of synthesis methods. Intended applications are mainly in the domain of programming assistance -- either to relieve professional programmers from routine tasks or to enable non-programmers to some limited form of end-user programming. Furthermore, in the future, inductive programming techniques might be applied to further areas such as supporting the inference of lemmata in theorem proving or learning grammar rules. Inductive automated program construction has been originally addressed by researchers in artificial intelligence and machine learning. During the last years, some work on exploiting induction techniques has been started also in the functional programming community. Therefore, the third workshop on |Approaches and Applications of Inductive Programming| took place for the first time in conjunction with the ACM SIGPLAN International Conference on Functional Programming (ICFP 2009). The first and second workshop were associated with the International Conference on Machine Learning (ICML 2005) and the European Conference on Machine Learning (ECML 2007). AAIP´09 aimed to bring together researchers from the functional programming and the artificial intelligence communities, working in the field of inductive functional programming, and advance fruitful interactions between these communities with respect to programming techniques for inductive programming algorithms, the identification of challenge problems and potential applications. For everybody interested in inductive programming we recommend to visit the website: www.inductive-programming.org

Artificial general intelligence: Proceedings of the Second Conference on Artificial General Intelligence, AGI 2009, Arlington, Virginia, USA, March 6-9, 2009

Artificial General Intelligence (AGI) research focuses on the original and ultimate goal of AI – to create broad human-like and transhuman intelligence, by exploring all available paths, including theoretical and experimental computer science, cognitive science, neuroscience, and innovative interdisciplinary methodologies. Due to the difficulty of this task, for the last few decades the majority of AI researchers have focused on what has been called narrow AI – the production of AI systems displaying intelligence regarding specific, highly constrained tasks. In recent years, however, more and more researchers have recognized the necessity – and feasibility – of returning to the original goals of the field. Increasingly, there is a call for a transition back to confronting the more difficult issues of human level intelligence and more broadly artificial general intelligence

LIPIcs, Volume 261, ICALP 2023, Complete Volume

LIPIcs, Volume 261, ICALP 2023, Complete Volum

TOWARDS A MODEL FOR ARTIFICIAL AESTHETICS - Contributions to the Study of Creative Practices in Procedural and Computational Systems

Este trabalho propõe o desenvolvimento de um modelo analítico e da terminologia a ele associada para o estudo de artefactos estéticos computacionais. Reconhecendo a presença e uso crescentes dos media computacionais, começamos por estudar como através da remediação eles transformam quantitativamente os media precedentes, e como as suas propriedades procedimentais e computacionais os afectam qualitativamente. Para perceber o potencial criativo e a especificidade dos media computacionais, desenvolvemos um modelo para a sua prática, crítica e análise. Como ponto de partida recorremos à tipologia desenvolvida por Espen Aarseth para o estudo de cibertextos, avaliando a sua adequação à análise de peças ergódicas visuais e audiovisuais, adaptando-a e expandindo-a com novas variáveis e respectivos valores. O modelo é testado através da análise de um conjunto de peças que representam diversas abordagens à criação procedimental e diversas áreas de actividade criativa contemporânea. É posteriormente desenvolvida uma análise de controlo para avaliar a usabilidade e utilidade do modelo, a sua capacidade para a elaboração de classificações objectivas e o rigor da análise. Demonstramos a adequação parcial do modelo de Aarseth para o estudo de artefactos não textuais e expandimo-lo para melhor descrever as peças estudadas. Concluímos que o modelo apresentado produz boas descrições das peças, agrupando-as logicamente, reflectindo afinidades estilísticas e procedimentais entre sistemas que, se estudados com base nas suas propriedades sensoriais ou nas suas estruturas de superfície provavelmente não revelariam muitas semelhanças. As afinidades reveladas pelo modelo são estruturais e procedimentais, e atestam a importância das características computacionais para a apreciação estética das obras. Verificamos a nossa conjectura inicial sobre a importância da procedimentalidade não só nas fases de desenvolvimento e implementação das obras mas também como base conceptual e estética na criação e apreciação artísticas, como um prazer estético

Computer science: the hardware software and heart of IT

1st edition, 201

Investigation of the potential beneficial effects of supplemental polyunsaturated fatty acids and glycosaminoglycans on the risk factors for calcium oxalate kidney stone formation using theoretical, experimental and human models

Includes bibliographical references.Introduction: Two hypotheses with regard to calcium oxalate (CaOx) renal stone formation were tested in this thesis. The first hypothesis is that fatty acid (FA) supplementation (n-6 and n-3) and chondroitin sulphate (CS) supplementation may reduce the plasma (FA) and urinary (FA and CS) risk factors for CaOx renal stone formation, and ultimately serve as therapeutic agents in the management of this disease. The notion that FAs may reduce plasma risk factors is based on previous studies which have shown that n-6 and n-3 FA supplementation reduces the concentrations of arachidonic acid, while the notion of an effect on urinary risk factors is based on reports of these supplements decreasing urinary calcium and/or oxalate excretion in animal and human studies. The notion of CS playing a role in reducing CaOx stone risk is based on its chemical structure which presents potential binding sites for calcium and magnesium. The second hypothesis is that black and white healthy South African subjects may respond differently to these dietary supplements and that these differences may provide insights which could account for the lower stone incidence in the former group compared to the latter. This hypothesis is based on the observation in many previous studies of different renal responses in the two race groups, to different dietary and supplemental challenges. FA’s and CS have not been previously investigated in this regard. Methods: These hypotheses were tested simultaneously by administering n-6 and n-3 FA supplements individually and in combination, and supplemental CS, to different groups of black and white healthy male subjects. For the FA studies, blood samples were analyzed for serum biomarkers (25-hydroxyvitamin 03 and triglycerides) for CaOx stone formation and FA profiles in plasma total phospholipids since arachidonic acid regulates calcium excretion. Urine samples were analyzed for individual CaOx stone risk factors, risk indices (Tiselius risk index and supersaturation (SS) of calcium oxalate, brushite and uric acid); crystallization experiments (metastable limit and crystal growth kinetics) were also conducted. For the CS studies, thermodynamic binding constants for calcium-CS and magnesium-CS complexes were determined by isothermal titration calorimetry. These constants were then used to model speciation in different urines using the computer program Joint Expert Speciation System (JESS), and to calculate supersaturation values under different urinary conditions. This was followed by in vitro crystallization experiments in which the effects of exogeneous CS on the CaOx metastable limit and CaOx crystallization kinetics were investigated in artificial and real urine samples. Finally, human studies were performed in which CS supplements were administered to subjects to test their efficacy on reducing the urinary risk factors for CaOx stone formation. Urines were analyzed and crystallization experiments were performed as described for the FA supplementation studies. Results: In the FA studies, favourable changes in the plasma CaOx stone risk factors were achieved by the supplementation of n-3 FA alone. Post-supplementation, the concentration of arachidonic acid in plasma total phospholipids was significantly reduced in both groups, thereby implying a reduction in urinary calcium excretion. However, FA supplementation had no positive effect on the urinary risk factors or on CaOx metastable limits and CaOx crystallization kinetics. In the CS studies, theoretical modelling showed that the reduction of ionized calcium concentrations can only be attainable at 100 times physiological concentrations of urinary CS and that the formation of the calcium-CS complex does not influence the urinary supersaturation of CaOx. The formation of the magnesium-CS complexes was unfavourable because it resulted in an increase in the concentrations of ionized oxalate, a risk factor for CaOx stone formation. The in vitro crystallization experiments showed that exogeneous CS at physiological and above physiological concentrations had no favourable effect on the metastable limit and crystal growth kinetics in all the tested urine samples. Finally, the human study showed that CS supplementation had no effect on urine chemistry and crystallization kinetics. Speciation calculations also showed that the SS values of CaOx and the concentrations of ionized calcium were not significantly changed by supplementation. Within groups, the effects of FA supplementation on the urinary risk factors were different. n-6 FA supplementation significantly increased magnesium and significantly decreased urate in the black group whereas in whites citrate, oxalate and potassium were significantly increased while ionized calcium was significantly reduced. In the n-3 FA study, magnesium was significantly increased and SS value of brushite was significantly decreased in whites. In the black group, there was no significant difference in the urinary risk factors after supplementation compared to baseline values. With regards to n-6 & n-3 FA supplementation, citrate was significantly increased while oxalate and SS CaOx were significantly decreased in the black group whereas in the white group, magnesium was significant increased. With regards to the CS study, SS values for brushite, tribasic calcium phosphate, hydroxylapatite and octacalcium phosphate decreased significantly in black subjects after CS supplementation, whereas the SS value for hydroxylapatite increased significantly in the white group. These effects could not be attributed to complexation of CS with calcium or magnesium. However, they are noteworthy because they are different in the two groups. Discussion: The results of these studies do not support the hypothesis that supplemental fatty acids or chondroitin sulfate have significant beneficial effects for reducing blood and urinary risk factors for calcium oxalate stone formation. Although the response to FA and CS supplementation was different between the two race groups, these findings did not provide new information to explain the difference in the incidence of calcium oxalate stone disease in the two population groups. The work described in this thesis provides a foundation for future studies in which CaOx stone patients, rather than healthy individuals are investigated