Semantic Predicate Types and Approximation for Class-based Object Oriented Programming

We apply the principles of the intersection type discipline to the study of class-based object oriented programs and; our work follows from a similar approach (in the context of Abadi and Cardelli's Varsigma-object calculus) taken by van Bakel and de'Liguoro. We define an extension of Featherweight Java, FJc and present a predicate system which we show to be sound and expressive. We also show that our system provides a semantic underpinning for the object oriented paradigm by generalising the concept of approximant from the Lambda Calculus and demonstrating an approximation result: all expressions to which we can assign a predicate have an approximant that satisfies the same predicate. Crucial to this result is the notion of predicate language, which associates a family of predicates with a class.Comment: Proceedings of 11th Workshop on Formal Techniques for Java-like Programs (FTfJP'09), Genova, Italy, July 6 200

Waterreservoirs op bedrijfsniveau alternatief voor zoetwatervoorziening landbouw?

De zoetwatervoorziening van de landbouw in Nederland staat hoog op de beleidsagenda. Het Rijk verbreedt het zoeken naar oplossingen voor het zoetwatervraagstuk van alleen kijken naar aanbod vanuit het hoofdwatersysteem naar ook het verkennen van de mogelijkheden voor grotere zelfvoorzienendheid. De vraag, die in dit artikel wordt behandeld, is of vasthouden van het neerslagoverschot in zoetwaterbekkens op bedrijfsniveau een redelijk alternatief vormt voor wateraanvoe

Ten years of infant mental health in the Netherlands:Who are the clients?

Background: Infant Mental Health (IMH) is a topic of current interest that emerged over the past decades, concerned with alleviating suffering and enhancing the social and emotional competence of young children. Worldwide there is increasing recognition of infant psychopathology meriting intervention. However, there are still limited data regarding the prevalence of psychiatric disorders and sociodemographic characteristics of these youngest of patients in clinical settings. Aim: This large, descriptive study aims at presenting the socio-demographic and clinical characteristics of infants referred consecutively to three outpatient Infant Mental Health teams in the Netherlands between September 2000 and July 2013. Methods: The medical records of 783 infants were retrospectively examined and the data were collected from paper and electronic patient files. Clinical and socio-demographic characteristics were categorized in child factors, developmental milestones, family factors and clinical outcome measures (DSM-IV, DC:0-3R, WIPPSI-III, SON-R 2½-7). Results: Our sample showed significantly more boys (543, 69%) than girls (240, 31%) being referred to the Infant Mental Health teams. Most children were referred when they were four or five years of age, both boys and girls. Mean duration of treatment was about a year and a half (20.34 months, SD 18.87) and most reported diagnoses were ADHD/behavioral disorders, ASS and disorder in infancy/childhood NOS. Familial psychiatric disorders were reported in 242 families (41%). These findings are discussed in the light of earlier research

Functional Type Assignment for Featherweight Java

Abstract. We consider functional type assignment for the class-based objectoriented calculus Featherweight Java. We start with an intersection type assignment systems for this calculus for which types are preserved under conversion. We then define a variant for which type assignment is decidable, and define a notion of unification as well as a principal typeing algorithm. We show the expressivity of both our calculus and our type system by defining an encoding of Combinatory Logic into our calculus and showing that this encoding preserves typeability. We thus demonstrate that the great capabilities of functional types can be applied to the context of class-based object orientated programming

GridPix application to dual phase TPC

GridPix is a gas-filled detector with an aluminium mesh stretched 50 μm above the Timepix CMOS pixel chip. This defines a high electric field where gas amplification occurs. A feasibility study is ongoing at Nikhef for the application of the GridPix technology as a charge sensitive device in a dual phase noble gas Time Projection Chamber (TPC), within the framework of the DARWIN design study for next generation dark matter experiments. The smallness of the device and well defined materials allow for high radio-purity and low outgassing. The high granularity of a pixel readout and the high detection efficiency of single electrons of GridPix bring benefits especially in terms of energy resolution for small energy deposits. This feature is interesting also for the measurement of the scintillation yield and the ionisation yield of noble liquids. The accurate measurements of such quantities have a direct impact on the data interpretation of dark matter experiments. The application in dual phase argon or xenon TPCs implies several technological challenges, such as the survival of the device at cryogenic temperature as well as the operation in a pure noble gas atmosphere without discharges. We describe here the recent developments of the project

Waterkwaliteit en landbouw: mag het ook een beetje zouter zijn?

Door de te verwachten gevolgen van de klimaatverandering zal de zoetwatervoorziening van Nederland de komende jaren worden heroverwogen. Daarbij zijn de berekening van de zoutschade in de landbouw als gevolg van beregening met niet-zoet oppervlaktewater en de hantering van normen voor toelaatbare chlorideconcentraties in het oppervlaktewater belangrijke onderdelen. In 2009 is het hierop betrekking hebbende deel van het huidige Droogte-instrumentarium geëvalueerd, gebruik makend van het agrohydrologisch SWAP model. In het aandachtsgebied zijn vier gewassen (gras, aardappelen, suikerbieten en tulpen) op drie grondsoorten (zavel, zand en klei) het meest relevant. Als belangrijkste bevindingen dat de berekening van de zoutschade niet onjuist is, maar dat de gehanteerde normen voor toelaatbare chlorideconcentraties in het oppervlaktewater leiden tot te veel droogteschade en herziening behoeve