On Independence Atoms and Keys

Uniqueness and independence are two fundamental properties of data. Their enforcement in database systems can lead to higher quality data, faster data service response time, better data-driven decision making and knowledge discovery from data. The applications can be effectively unlocked by providing efficient solutions to the underlying implication problems of keys and independence atoms. Indeed, for the sole class of keys and the sole class of independence atoms the associated finite and general implication problems coincide and enjoy simple axiomatizations. However, the situation changes drastically when keys and independence atoms are combined. We show that the finite and the general implication problems are already different for keys and unary independence atoms. Furthermore, we establish a finite axiomatization for the general implication problem, and show that the finite implication problem does not enjoy a k-ary axiomatization for any k

The three worlds and two sides of mathematics and a visual construction for a continuous nowhere differentiable function

Peer reviewe

Third Graders' Perceptions on Moral Behaviour on Bullying If They Had the Infinite Powers of Superhero Defenders

Bullying is a serious moral concern affecting the victim's welfare and achievement in school. Lately, research on bullying phenomenon has led to successful procedures in which passive bystanders are asked to become defenders of the victims of bullying. This case study explores children's perceptions on moral behaviour on bullying and, moreover, what type of moral voice they would express if they had the infinite powers and means of superhero defenders. Children created masks, posters, and flags for ideal superheroes and described their personalities. In addition, they drew comic strips about the skills they wish to teach new hero students in superhero school. The results indicate that children's moral voices can be divided primarily into justice and care. In addition, some expressed also the dark voice of the vigilante. Findings suggest that superheroes offer one tool for educators and children to ponder about the role of defenders for the victims of bullying. The topic focuses on the core of school life, relationships between pupils, and their moral development. Sixteen third grade children (aged 9-10) from a primary school in Finland took part in the study. The results for two of the children are presented in detail as the basis for discussion.Peer reviewe

Transmissio-desorptiofotoionisaatio-massaspektrometria

Ambient mass spectrometry includes methods where ions are produced outside of the mass spectrometry in atmospheric pressure direct from the surface of the sample without sample preparation. The first and most popular ambient ionization methods are DESI, desorption electrospray ionization and DART, direct analysis in real time. DAPPI, desorption atmospheric pressure photoionization is an ionization method where samples are desorbed with hot vapor from surface and then ionized by photoionization. The aim of this study was to develop desorption atmospheric pressure photoionization method in transmission geometry. In transmission geometry hot vapor for microchip is directed through metal or polymer meshes to mass spectrometer inlet. Liquid samples can be analyzed either by soaking the mesh to liquid sample or apply a sample droplet to the mesh. Hot vapor desorbs analytes from the mesh and analytes are ionized in a gas phase by photoionization using VUV lamp. In this method optimal positioning of the mesh and the microchip was determined. Additionally optimal microchip heating power, dopant flow rate, nebulizer gas flow rate, capillary voltage and drying gas parameters were determined. Optimized method was applied for analyzing standard samples, vitamin juice samples and milk samples. According the analysis with authentic samples, transmission mode DAPPI can be applied for analyzing liquid samples without sample preparation. According the analysis with standard samples, transmission mode DAPPI can be applied for extraction of hydrophobic analytes from water samples. Comparing to conventional DAPPI, in transmission mode DAPPI spectra, intensities of the background ions are lower resulting higher signal-to-noise ratios with transmission mode DAPPI.Suorilla desorptioionisaatiotekniikoilla tarkoitetaan menetelmiä, joissa ionit tuotetaan massaspektrometrin ulkopuolella ilmanpaineessa suoraan näytteen pinnalta ilman esikäsittelyä. Ensimmäisiä ja käytetyimpiä suoria desorptioionisaatiotekniikoita olivat DESI (desorption electrospray ionization) ja DART (direct analysis in real time). DAPPI (desorption atmospheric pressure photoionization) on ilmanpaineessa toimiva ionisaatiomenetelmä jossa näyte irrotetaan pinnalta kuuman liuotinhöyryn avulla ja ionisoidaan fotoionisaatiolla. Työn tavoitteena oli kehittää transmissio-desorptiofotoionisaatiomenetelmä massaspektrometrille. Transmissiogeometrialla tarkoitetaan asetelmaa, jossa desorptio tapahtuu näytteen läpi. Asetelmassa käytetään teräs- ja polymeeriverkkoja joiden läpi ohjataan lämmitettävästä mikrosirusta kuumaa liuotinhöyryä suoraan kohti massaspektrometrin sisääntuloa. Nestemäisiä näytteitä voidaan analysoida joko upottamalla verkko näytteeseen ja siirtämällä suoraan analysoitavaksi tai pipetoimalla nestemäistä näytettä verkolle. Höyry desorboi analyytit verkolta, jonka jälkeen ne ionisoidaan fotoionisaatiolla UV-lampun avulla kaasufaasissa. Kehitetty menetelmä optimoitiin eli määritettiin optimaalinen näyteverkon paikka suhteessa mikrosiruun ja massaspektrometrin sisääntuloon, selvitettiin optimaalinen mikrosirun etäisyys massaspektrometristä. Lisäksi määritettiin optimiarvot mikrosirun lämmitysteholle, liuottimen virtausnopeudelle, typpikaasun virtausnopeudelle, kapillaarin jännitteelle sekä kuivauskaasun parametreille. Menetelmällä analysoitiin standardinäytteitä, vitamiineja sisältäviä mehunäytteitä sekä maitonäytteitä. Autenttisten näytteiden analyysien perusteella transmissio-DAPPImenetelmä soveltuu nestemäisten näytteiden analysointiin ilman näytteen esikäsittelyä. Standardinäytteillä tehtyjen analyysien perusteella PEEK-verkkoa voidaan käyttää hydrofobisten analyyttien uuttamiseen vesinäytteistä. Verrattaessa perinteiseen DAPPI:iin, transmissio-DAPPI:n spektrissä taustaionien intensiteetit ovat heikompia josta seuraa saavutettu parempi signaali/kohina-suhde

On elementary logics for quantitative dependencies

We define and study logics in the framework of probabilistic team semantics and over metafinite structures. Our work is paralleled by the recent development of novel axiomatizable and tractable logics in team semantics that are closed under the Boolean negation. Our logics employ new probabilistic atoms that resemble so-called extended atoms from the team semantics literature. We also define counterparts of our logics over metafinite structures and show that all of our logics can be translated into functional fixed point logic implying a polynomial time upper bound for data complexity with respect to BSS-computations.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Polyteam semantics

Team semantics is the mathematical framework of modern logics of dependence and independence in which formulae are interpreted by sets of assignments (teams) instead of single assignments as in first-order logic. In order to deepen the fruitful interplay between team semantics and database dependency theory, we define Polyteam Semantics in which formulae are evaluated over a family of teams. We begin by defining a novel polyteam variant of dependence atoms and give a finite axiomatization for the associated implication problem. We relate polyteam semantics to team semantics and investigate in which cases logics over the former can be simulated by logics over the latter. We also characterize the expressive power of poly-dependence logic by properties of polyteams that are downwards closed and definable in existential second-order logic (ESO). The analogous result is shown to hold for poly-independence logic and all ESO-definable properties. We also relate poly-inclusion logic to greatest fixed point logic.Peer reviewe

On the Interaction of Inclusion Dependencies with Independence Atoms

Proceeding volume: 46Inclusion dependencies are one of the most important database constraints. In isolation their finite and unrestricted implication problems coincide, are finitely axiomatizable, PSPACE-complete, and fixed-parameter tractable in their arity. In contrast, finite and unrestricted implication problems for the combined class of functional and inclusion de- pendencies deviate from one another and are each undecidable. The same holds true for the class of embedded multivalued dependencies. An important embedded tractable fragment of embedded multivalued dependencies are independence atoms. These stipulate independence between two attribute sets in the sense that for every two tuples there is a third tuple that agrees with the first tuple on the first attribute set and with the second tuple on the second attribute set. For independence atoms, their finite and unrestricted implication problems coincide, are finitely axiomatizable, and decidable in cubic time. In this article, we study the implication problems of the combined class of independence atoms and inclusion dependencies. We show that their finite and unrestricted implication problems coincide, are finitely axiomatizable, PSPACE-complete, and fixed-parameter tractable in their arity. Hence, significant expressivity is gained without sacrificing any of the desirable properties that inclusion dependencies have in isolation. Finally, we establish an efficient condition that is sufficient for independence atoms and inclusion dependencies not to inter- act. The condition ensures that we can apply known algorithms for deciding implication of the individual classes of independence atoms and inclusion dependencies, respectively, to decide implication for an input that combines both individual classes.Peer reviewe

On quantified propositional logics and the exponential time hierarchy

We study quantified propositional logics from the complexity theoretic point of view. First we introduce alternating dependency quantified boolean formulae (ADQBF) which generalize both quantified and dependency quantified boolean formulae. We show that the truth evaluation for ADQBF is AEXPTIME(poly)-complete. We also identify fragments for which the problem is complete for the levels of the exponential hierarchy. Second we study propositional team-based logics. We show that DQBF formulae correspond naturally to quantified propositional dependence logic and present a general NEXPTIME upper bound for quantified propositional logic with a large class of generalized dependence atoms. Moreover we show AEXPTIME(poly)-completeness for extensions of propositional team logic with generalized dependence atoms.University of AucklandAcademy of Finlan