Decomposition of select expressions

A select operation that is part of an expression applying to a relational database is decomposed into one or more independent select operations for the purpose of optimising the relational expression. The select expression is treated as a logical expression. From the canonical form of this expression an optimal conjunctive form is obtained which can be decomposed into separate select operations. These separate selects can then be moved to the most effective place within the relational expression. The method also eliminates redundancy in the original expression. A prototype has been used in developing the optimisation method; from this prototype an implementation for use in an actual system has been derived

Contrail Formation: Exploring options for improving prediction methods on the Formation of Contrails from Modern Turbofan Engines

The validity of current prediction methods for the formation of contrails from modern turbofan engines is investigated. A modelling framework has been developed for estimating the impact of engine configurations on contrail formation by analyzing the physics of the mixing between core and bypass flow. Within this framework, Engine Performance Modelling yields the flow conditions at exhaust nozzle exits. A 2D axisymmetric CFD Flow Field Solver then determines the flow parameters behind the engine. Water vapour dispersion is simulated using a species transport model, after which contrail locations are determined by a set of criteria for homogeneous ice crystal formation. Finally, particles are tracked to determine mixing lines, which are compared to those from current prediction methods. From a Leap-1A engine case study using this framework, it can be concluded that assumptions of instantaneous mixing underlying current methods are not valid, resulting in their overestimation of the mixing line gradient.Aerospace Engineerin

Horizonverkenning Noord-Nederland; een scenariostudie voor het landelijk gebied van Groningen, Friesland en Drenthe in 2030

Directie Noord van het Ministerie van Landbouw, Natuurbeheer en Visserij heeft de behoefte aan een toekomstverkenning voor Noord-Nederland ter ondersteuning van de strategische beleidsvorming. Hiervoor zijn drie scenario's ontworpen: `Raamwerk', `Weefwerk' en `Marktwerk'. Van elk van de scenario's zijn de effecten op landbouw, natuur, landschap en recreatie bepaald. In `Raamwerk' zijn de ontwikkelingen grootschalig en zijn de functies gescheiden. Het aantal arbeidsplaatsen in de landbouw daalt met 5z% per jaar. Natuurontwikkeling vindt plaats in grote eenheden begeleid-natuurlijke natuur. Er ontstaat een duidelijke landschapstructuur op landsdelig niveau. `Weefwerk' zijn functies meer verweven en is het landschap kleinschaliger. Agrariërs hebben vaak nevenactiviteiten buiten de landbouw waardoor de landbouwbedrijven weinig in omvang toenemen en het aantal werkenden in de landbouw met slechts 1% per jaar daalt. Er ontstaan grote aaneengesloten gebieden waar natuurontwikkeling verweven is met andere functies. De duurzaamheid van dierpopulaties neemt in dit scenario het sterkst toe. Ook de verschillende landschapstypen blijven behouden of worden versterkt. In `Marktwerk' verdwijnt het markt- en prijsbeleid in de landbouw en stuurt de overheid de ruimtelijke ordening slechts op hoofdlijnen. De akkerbouw in Noord-Nederland moet plaatsmaken voor grote veehouderijbedrijven. Het aantal werkenden in de landbouw daalt ruimt 4% per jaar. Bestaande landschapswaarden worden in dit scenario het meest aangetast. Met name waterrecreatie neemt sterk toe, waardoor overdruksituaties rond de Friese Meren kunnen ontstaan

Toward Data Centered Tools for Understanding and Transforming Legacy Business Applications Abstract

We assert that tools for understanding and transforming legacy business applications should be built around logical data models, rather than the structure of source code artifacts or control flow. In this position paper, we argue that data centered tools are beneficial for a variety of frequently-occurring code understanding and transformation scenarios for legacy business applications, and outline the goals and status of the Mastery project at IBM Research, whose aim is to build a suite of logical model recovery tools, focusing initially on data models. 1 The Problem For the past two years, our group at IBM’s T.J. Watson Research Center has been investigating tools and techniques for analyzing and transforming legacy business applications, focusing on mainframe-based systems written in Cobol. Many such applications have evolved over the course of decades, and, although the

Serum 25-hydroxyvitamin D is associated with cognitive executive function in Dutch prefrail and frail elderly: a cross-sectional study exploring the associations of 25-hydroxyvitamin D with glucose metabolism, cognitive performance and depression

Objectives: The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH] D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels. Design, Setting, and Participants: Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria. Measurements: Associations of 25(OH) D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression. Results: No associations were observed for 25(OH) D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH) D was positively associated with executive functioning (beta 0.007, P=.01) and tended to be associated with information-processing speed (beta 0.006, P=.06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression. Conclusion: This cross-sectional study suggests an association of serum 25(OH) D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated

Serum 25-hydroxyvitamin D is associated with cognitive executive function in Dutch prefrail and frail elderly: a cross-sectional study exploring the associations of 25-hydroxyvitamin D with glucose metabolism, cognitive performance and depression

Objectives: The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH] D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels. Design, Setting, and Participants: Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria. Measurements: Associations of 25(OH) D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression. Results: No associations were observed for 25(OH) D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH) D was positively associated with executive functioning (beta 0.007, P=.01) and tended to be associated with information-processing speed (beta 0.006, P=.06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression. Conclusion: This cross-sectional study suggests an association of serum 25(OH) D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated. Copyright (C) 2013 - American Medical Directors Association, Inc