NMR studies of domain switching in ferroelectric rochelle salt

Nuclear magnetic resonance of domain switching in ferroelectric rochelle sal

Intension, substance and calculus:the leibnizian vision in Frank Ankersmit’s philosophy of history

Abstract. F. R. Ankersmit’s philosophy of history features three distinct categories. Historical research is epistemological. It deals with historical theory and language and logic as they ordinarily are thought of in analytic philosophy. History-writing is the most prominent part of his work and it is explained in terms of representation and aesthetics. Finally, there is historical experience, which could be called the metaphysics of his system. The latter two categories have been Ankersmit’s focus all his career, while the first one is only referred to when establishing how the latter two are distinguished from it. In this master’s thesis an account is given for how all these categories can be explained in terms of G. W. Leibniz’s theory of substance. While historical research is potentially analogous to Leibniz’s ideas about corporeal substance, Ankersmit expresses little interest in it. Instead, his focus is on the idealistic metaphysics presented in Leibniz’s monadology. In this system the substance is defined as simple, unextended, and complete in the sense that it is an individual, that is utterly independent of outside influence apart from God. On the other hand, substance in the monadology is defined as perception, sometimes conscious, as is the case with souls. This dichotomy is central for Ankersmit’s theory of historical representation as he argues that the main product of historiography, the historical representation, is analogous to Leibniz’s substance. It is an indivisible individual and therefore requires to be thought of as a whole and evaluated in aesthetic terms instead of traditional analysis. On the other hand, with the theory of historical experience the status of the monad as pure experience is central. These two aspects are for him two sides of the same coin that is the basis of his philosophy of history. Thirdly, just as Leibniz’s discovery of the calculus had a profound effect on his metaphysics, so it is important in the application of Ankersmit’s representational logic. The notion is applied analogically in his explanation of what the historian aims at in writing of history. It also explains how philosophers of history collectively may decide upon which representation of a given topic is best. I argue that a clear vision about Ankersmit’s Leibnizianism is beneficial if one is to understand the motivations and goals of his philosophy. Just as it was characteristic for Leibniz to appear a conciliator of different sects in the philosophy of his time, so it is Ankersmit’s most important aim to provide philosophy of history an apriorist platform upon which genuine debate based on contesting representations is possible.Tiivistelmä. F. R. Ankersmitin historianfilosofiassa on kolme selkeää osa-aluetta. ”Historiantutkimus” on epistemologista. Siinä keskiössä ovat teoria ja kieli, siten kuin aikamme analyyttinen filosofia näitä asioita lähestyy. “Historiankirjoituksella" hän viittaa historioitsijoiden tekstien representatiiviseen olemukseen. Kokonaistekstejä voi hänen mielestään arvioida vain esteettisin perustein, sillä ne ovat ensisijaisesti representaatioita. ”Historiallinen kokemus” taas käsittelee historian ontologiaa. Kaksi jälkimmäistä käsitettä ovat hänen työssään keskiössä. Tässä työssä esitän, että kaikki nämä kolme osa-aluetta voidaan ymmärtää G. W. Leibnizin substanssiteorian puitteissa. “Historiantutkimus” voidaan nähdä analogisena Leibnizin ulottuvan (corporeal) substanssin teorian kanssa, vaikkakaan Ankersmit ei tätä vertausta itse tee. Sen sijaan hän soveltaa Leibnizin monadologian idealistista metafysiikkaa. Monadologiassa substanssi on yksinkertainen, jakamaton ja täydellinen yksilö, johon mikään ulkopuolinen ei vaikuta. Toisaalta Leibnizin substanssi tulee määritellyksi myös havaitsemisena, joka voi olla tietoista, kuten on esimerkiksi sielujen laita. Molemmat määritelmät tulevat osaksi Ankersmitin historianfilosofiaa hänen vetäessään analogian Leibnizin substanssin ja oman käsitteensä, historiallisen representaation, välille. Representaatio on holistinen yksilö, jota ei voi siten analysoida, vaan jonka arviointi on esteettistä. Toisaalta, historiallisen kokemuksen teoriassa substanssin asema nimenomaan puhtaana perseptiona ja kokemisena korostuu. Historiallinen representaatio ja historiallinen kokemus muodostavat Ankersmitin filosofiassa rikkumattoman kokonaisuuden. Lisäksi, Leibniz oli uranuurtaja differentiaali- ja integraalilaskennasta. Tällä matemaattisella ymmärryksellä oli vaikutus myös hänen metafysiikkansa kehitykseen. Analogisesti Ankersmit näkee sille sovelluksen myös omassa työssään. Differentiaalikalkyylin käsitteen avulla tämä selittää tarkemmin historiallisen representaation luonnetta niin yksittäisen historioitsijan kuin myös koko yhteisön näkökulmasta. Yksilö pyrkii parhaaseen mahdolliseen representaatioon ja yhteisö pyrkii yhteisymmärrykseen parhaasta mahdollisesta representaatiosta. Väitän, että Ankersmitin “Leibnizilaisuuden” ymmärtäminen on tärkeää, mikäli halutaan ymmärtää paitsi hänen filosofiaansa yleensä, myös hänen motiivejaan ja tavoitteitaan. Leibniz halusi aikanaan luoda järjestelmän, jonka pohjalta kaikki filosofiset erimielisyydet voitaisiin rationaalisesti ratkaista. Ankersmit pyrkii samanlaiseen sovittelevaan rooliin historianfilosofiassa väittäessään, että hänen järjestelmänsä on aprioristinen perusta, jonka pohjalta erilaiset historialliset näkökulmat voidaan asettaa aitoon vuoropuheluun keskenään

Independent component analysis: algorithms and applications

A fundamental problem in neural network research, as well as in many other disciplines, is finding a suitable representation of multivariate data, i.e. random vectors. For reasons of computational and conceptual simplicity, the representation is often sought as a linear transformation of the original data. In other words, each component of the representation is a linear combination of the original variables. Well-known linear transformation methods include principal component analysis, factor analysis, and projection pursuit. Independent component analysis (ICA) is a recently developed method in which the goal is to find a linear representation of nongaussian data so that the components are statistically independent, or as independent as possible. Such a representation seems to capture the essential structure of the data in many applications, including feature extraction and signal separation. In this paper, we present the basic theory and applications of ICA, and our recent work on the subject

SAS Macros for Calculation of Population Attributable Fraction in a Cohort Study Design

The population attributable fraction (PAF) is a useful measure for quantifying the impact of exposure to certain risk factors on a particular outcome at the population level. Recently, new model-based methods for the estimation of PAF and its confidence interval for different types of outcomes in a cohort study design have been proposed. In this paper, we introduce SAS macros implementing these methods and illustrate their application with a data example on the impact of different risk factors on type 2 diabetes incidence.

A geometric Newton method for Oja's vector field

Newton's method for solving the matrix equation $F(X)\equiv AX-XX^TAX=0$ runs up against the fact that its zeros are not isolated. This is due to a symmetry of $F$ by the action of the orthogonal group. We show how differential-geometric techniques can be exploited to remove this symmetry and obtain a ``geometric'' Newton algorithm that finds the zeros of $F$. The geometric Newton method does not suffer from the degeneracy issue that stands in the way of the original Newton method

Smad signalling in the ovary

has now been a decade since the first discovery of the intracellular Smad proteins, the downstream signalling molecules of one of the most important growth factor families in the animal kingdom, the transforming growth factor beta (TGF-beta) superfamily. In the ovary, several TGFbeta superfamily members are expressed by the oocyte, granulosa and thecal cells at different stages of folliculogenesis, and they signal mainly through two different Smad pathways in an autocrine/paracrine manner. Defects in the upstream signalling cascade molecules, the ligands and receptors, are known to have adverse effects on ovarian organogenesis and folliculogenesis, but the role of the individual Smad proteins in the proper function of the ovary is just beginning to be understood for example through the use of Smad knockout models. Although most of the different Smad knockouts are embryonic lethal, it is known, however, that in Smad1 and Smad5 knockout mice primordial germ cell development is impaired and that Smad3 deficient mice harbouring a deletion in exon 8 exhibit impaired folliculogenesis and reduced fertility. In this minireview we discuss the role of Smad structure and function in the ovarian context.has now been a decade since the first discovery of the intracellular Smad proteins, the downstream signalling molecules of one of the most important growth factor families in the animal kingdom, the transforming growth factor beta (TGF-beta) superfamily. In the ovary, several TGFbeta superfamily members are expressed by the oocyte, granulosa and thecal cells at different stages of folliculogenesis, and they signal mainly through two different Smad pathways in an autocrine/paracrine manner. Defects in the upstream signalling cascade molecules, the ligands and receptors, are known to have adverse effects on ovarian organogenesis and folliculogenesis, but the role of the individual Smad proteins in the proper function of the ovary is just beginning to be understood for example through the use of Smad knockout models. Although most of the different Smad knockouts are embryonic lethal, it is known, however, that in Smad1 and Smad5 knockout mice primordial germ cell development is impaired and that Smad3 deficient mice harbouring a deletion in exon 8 exhibit impaired folliculogenesis and reduced fertility. In this minireview we discuss the role of Smad structure and function in the ovarian context.has now been a decade since the first discovery of the intracellular Smad proteins, the downstream signalling molecules of one of the most important growth factor families in the animal kingdom, the transforming growth factor beta (TGF-beta) superfamily. In the ovary, several TGFbeta superfamily members are expressed by the oocyte, granulosa and thecal cells at different stages of folliculogenesis, and they signal mainly through two different Smad pathways in an autocrine/paracrine manner. Defects in the upstream signalling cascade molecules, the ligands and receptors, are known to have adverse effects on ovarian organogenesis and folliculogenesis, but the role of the individual Smad proteins in the proper function of the ovary is just beginning to be understood for example through the use of Smad knockout models. Although most of the different Smad knockouts are embryonic lethal, it is known, however, that in Smad1 and Smad5 knockout mice primordial germ cell development is impaired and that Smad3 deficient mice harbouring a deletion in exon 8 exhibit impaired folliculogenesis and reduced fertility. In this minireview we discuss the role of Smad structure and function in the ovarian context.Peer reviewe

d0 Ferromagnetic Interface Between Non-magnetic Perovskites

We use computational and experimental methods to study d0 ferromagnetism at a charge- imbalanced interface between two perovskites. In SrTiO3/KTaO3 superlattice calculations, the charge imbalance introduces holes in the SrTiO3 layer, inducing a d0 ferromagnetic half-metallic 2D electron gas at the interface oxygen 2p orbitals. The charge imbalance overrides doping by vacancies at realistic concentrations. Varying the constituent materials shows ferromagnetism to be a gen- eral property of hole-type d0 perovskite interfaces. Atomically sharp epitaxial d0 SrTiO3/KTaO3, SrTiO3 /KNbO3 and SrTiO3 /NaNbO3 interfaces are found to exhibit ferromagnetic hysteresis at room temperature. We suggest the behavior is due to high density of states and exchange coupling at the oxygen t1g band in comparison with the more studied d band t2g symmetry electron gas.Comment: 5 pages, 5 figure

View-tolerant face recognition and Hebbian learning imply mirror-symmetric neural tuning to head orientation

The primate brain contains a hierarchy of visual areas, dubbed the ventral stream, which rapidly computes object representations that are both specific for object identity and relatively robust against identity-preserving transformations like depth-rotations. Current computational models of object recognition, including recent deep learning networks, generate these properties through a hierarchy of alternating selectivity-increasing filtering and tolerance-increasing pooling operations, similar to simple-complex cells operations. While simulations of these models recapitulate the ventral stream's progression from early view-specific to late view-tolerant representations, they fail to generate the most salient property of the intermediate representation for faces found in the brain: mirror-symmetric tuning of the neural population to head orientation. Here we prove that a class of hierarchical architectures and a broad set of biologically plausible learning rules can provide approximate invariance at the top level of the network. While most of the learning rules do not yield mirror-symmetry in the mid-level representations, we characterize a specific biologically-plausible Hebb-type learning rule that is guaranteed to generate mirror-symmetric tuning to faces tuning at intermediate levels of the architecture

Canonical analysis based on scatter matrices.

In this paper, the influence functions and limiting distributions of the canonical correlations and coefficients based on affine equivariant scatter matrices are developed for elliptically symmetric distributions. General formulas for limiting variances and covariances of the canonical correlations and canonical vectors based on scatter matrices are obtained. Also the use of the so-called shape matrices in canonical analysis is investigated. The scatter and shape matrices based on the affine equivariant Sign Covariance Matrix as well as the Tyler's shape matrix serve as examples. Their finite sample and limiting efficiencies are compared to those of the Minimum Covariance Determinant estimators and S-estimator through theoretical and simulation studies. The theory is illustrated by an example.Canonical correlations; Canonical variables; Canonical vectors; Covariance; Covariance determinant estimator; Determinant estimator; Distribution; Efficiency; Estimator; Functions; Influence function; Matrix; Principal components; Scatter; Shape matrix; Sign; Sign covariance mix; Simulation; Studies; Theory; Tyler's estimate; Variance;

Exploring Referee Abuse Through the Lens of the Collegiate Rugby Coach

Referees are valuable contributors to the legitimacy of a sporting contest. Despite this, abuse in sport has become a growing concern and is regularly noted as an obstacle with which referees must contend. Continued abuses have been associated with referee discontinuation and have been noted as a detrimental influence in the recruitment and retention of referees. Sporting organizations, coaches, and players all feel the impact when there is an inadequate supply of referees. Coaches have been noted as a primary perpetrator of referee abuse; thus, in this study, the authors utilize a phenomenological approach to explore perceptions of referee abuse through the lens of the collegiate rugby coach. Data were collected from 15 participants, all of whom completed two phone interviews. Five factors that influence one\u27s perceptions of and proclivity towards referee abuse emerged from the data: (a) personal characteristics/philosophies, (b) relationships, (c) social influences, (d) organizational expectations, and (e) culture. Implications to practice and recommendations for future research are discussed