1-D hydrogen-bonded organization of hexanuclear {3d-4f-5d} complexes: evidence for slow relaxation of the magnetization for [{LMe2Ni(H2O)Ln(H2O)4.5}2{W(CN)8}2] with Ln = Tb and Dy

Heterometallic {3d-4f-5d} aggregates with formula [{LMe2Ni(H2O)Ln(H2O)4.5}2{W(CN)8}2]·15H2O, (LMe2 stands for N,N-2,2-dimethylpropylenedi(3-methoxysalicylideneiminato) Schiff-base ligand) with Ln = Gd, Tb, Dy, have been obtained by reacting bimetallic [LMe2Ni(H2O)2Ln(NO3)3] and Cs3{W(CN)8} in H2O. The hexanuclear complexes are organized in 1-D arrays by means of hydrogen bonds established between the solvent molecules coordinated to Ln and the CN ligands of an octacyanometallate moiety. The X-ray structure was solved for the Tb derivative. Magnetic behavior indicates ferromagnetic {W–Ni} and {Ni–Ln} interactions (JNiW = 18.5 cm-1, JNiGd = 1.85 cm-1) as well as ferromagnetic intermolecular interactions mediated by the H-bonds. Dynamic magnetic susceptibility studies reveal slow magnetic relaxation processes for the Tb and Dy derivatives, suggesting SMM type behavior for these compounds.

Statistical and Information-Theoretic Methods for Data-Analysis

In this Thesis, we develop theory and methods for computational data analysis. The problems in data analysis are approached from three perspectives: statistical learning theory, the Bayesian framework, and the information-theoretic minimum description length (MDL) principle. Contributions in statistical learning theory address the possibility of generalization to unseen cases, and regression analysis with partially observed data with an application to mobile device positioning. In the second part of the Thesis, we discuss so called Bayesian network classifiers, and show that they are closely related to logistic regression models. In the final part, we apply the MDL principle to tracing the history of old manuscripts, and to noise reduction in digital signals.

Computing the Stochastic Complexity of Simple Probabilistic Graphical Models

Minimum Description Length (MDL) is an information-theoretic principle that can be used for model selection and other statistical inference tasks. There are various ways to use the principle in practice. One theoretically valid way is to use the normalized maximum likelihood (NML) criterion. Due to computational difficulties, this approach has not been used very often. This thesis presents efficient floating-point algorithms that make it possible to compute the NML for multinomial, Naive Bayes and Bayesian forest models. None of the presented algorithms rely on asymptotic analysis and with the first two model classes we also discuss how to compute exact rational number solutions.

Topochemically controlled hydrogen reduction of scheelite-related rare-earth metal molybdates

Scheelite-related -Ln2Mo3O12(Ln = La, Pr, Nd, Sm, Gd, Tb, or Dy) oxides are reduced by hydrogen at 780–870 K yielding molybdenum (IV) oxides of formula Ln2Mo3O9. The latter crystallize in a tetragonal scheelite (ABO4) type structure where one third of the A sites and a quarter of the anion sites are vacant: Ln2/3(cat)1/3MoO3(an). The reaction Ln2Mo3O12+ 3H2 Ln2Mo3O9(an)3+ 3H2O may be regarded as topochemically controlled, since both the parent and the product phases have scheelite-related structures. Infrared spectra and electrical and magnetic properties of these metastable defect scheelite phases are reported.

A data fusion approach of multiple maintenance data sources for real-world reliability modelling

A central tenet in the theory of reliability modelling is the quantification of the probability of asset failure. In general, reliability depends on asset age and the maintenance policy applied. Usually, failure and maintenance times are the primary inputs to reliability models. However, for many organisations, different aspects of these data are often recorded in different databases (e.g. work order notifications, event logs, condition monitoring data, and process control data). These recorded data cannot be interpreted individually, since they typically do not have all the information necessary to ascertain failure and preventive maintenance times. This paper presents a methodology for the extraction of failure and preventive maintenance times using commonly-available, real-world data sources. A text-mining approach is employed to extract keywords indicative of the source of the maintenance event. Using these keywords, a Naïve Bayes classifier is then applied to attribute each machine stoppage to one of two classes: failure or preventive. The accuracy of the algorithm is assessed and the classified failure time data are then presented. The applicability of the methodology is demonstrated on a maintenance data set from an Australian electricity company.

Ternary bismuth oxides Bi26â-xMxO40ay (M = Mg, Al, Co and Ni) related to α - Bi2O3

Reaction of Bi2O3 with MgO, NiO, Co3O4 and Al2O3 gives rise to the corresponding ternary bismuth oxides, Bi18Mg8O36, Bi18Ni8O36, Bi20Co6O39 and Bi24Al2O39. These oxides have the general formula Bi26�xMxO40�y and exhibit BCC structures related to α - Bi2O3. In the first three solids, the metal ions, M, replace bismuth randomly at the octahedral 24r sites (space group 123); in the last case, aluminium ions occupy the tetrahedral 2a sites, the phase being isostructural with Bi24Ge2O40. Starting from Bi2O3 and NiO, orthorhombic Bi2Ni2O5 has also been obtained.

Complexes of lanthanide iodides with 3-methylpyridine-1-oxide

Complexes of lanthanide iodides with 3-methylpyridine-1-oxide of the formula Ln(3-MePyO)8I3.xH2O where x = 0 for Ln = La and Tb, x = 1 for Ln = Pr, and x = 2 for Ln = Nd, Sm, Dy, Yb, and Y have been prepared and characterized by chemical analyses, conductance, infrared, proton nmr, and DTA data. Infrared and proton nmr data have been interpreted in terms of the coordination of the ligand to the metal ion through the oxygen of the N—O group. Proton nmr spectrum of the Yb(III) complex is indicative of a restricted rotation of the pyridine ring about the N—O bond.

Structural studies of analgesics and their interactions. II. The crystal structure of a 1:1 complex between antipyrine and salicyclic acid (salipyrine)

The complex crystallizes in the space group P21/c with four formula units in a unit cell of dimensions a= 12.747, b= 7.416, c= 17.894 A and/3= 90.2 °. The structure has been solved by the symbolic addition procedure using three-dimensional photographic data and refined to an R value of 0.079 for 2019 observed reflexions. The pyramidal nature of the two hetero nitrogen atoms in the antipyrine molecule is inter:nediate between that observed in free antipyrine and in some of its metal complexes. The molecule is more polar than that in crystals of free antipyrine but less so compared with that in metal complexes. In the salicylic acid molecule, the hydroxyl group forms an internal hydrogen bond with one of the oxygen atoms in the carboxyl group. The association between the salicylic acid and the antipyrine molecules is achieved through an intermolecular hydrogen bond with the other carboxyl oxygen atom in the salicylic acid molecule as the proton donor and the carboxyl oxygen atom of the antipyrine molecule as the acceptor.

Helluntailiikkeen spiritualiteetti : Tilastollinen tutkimus Helsingin Saalem-seurakunnan tilaisuuksiin osallistuvien spiritualiteetista

Yleisellä tasolla tutkimuksen kohteena oli Suomen helluntailiikkeen spiritualiteetti. Tutkimuksen kehysperusjoukkona oli Helsingin Saalem-seurakunnan tilaisuuksiin osallistuvat ihmiset. Aineisto kerättiin kyselylomakkeilla syksyllä 2004 Saalem-seurakunnan tilaisuuksissa. Täytettyjä lomakkeita kertyi 230. Vastaajien ikä vaihteli 13-87 vuoteen ja heistä 36% olimiehiä. 70% kuului Saalem-seurakuntaan ja 17% johonkin toiseen helluntaiseurakuntaan. Ei-helluntailaisia oli 13% vastaajista. Rajoittuneelta osin käytössä oli myös 500 vastaajan vertailuaineisto Kallion kaupunginosan alueelta. Tämän niinsanotun Case Kallio -aineiston vastaajat olivat pääsääntöisesti heikosti sitoutuneita kristinuskon oppeihin sekä hartaudenharjoittamiseen. Vastaajista 50% oli miehiä. Ikä vaihteli 18-39-uoden välillä. Teoreettisena lähtökohtana tutkimukselle toimi yhdysvaltalaisen Daniel Albrechtin empiirinen tutkimus helluntailais-karismaattisesta spiritualiteetista. Hän määrittelee helluntailais-karismaattisen spiritualiteetin muodostuvan kolmesta tekijästä: uskomuksista, käytännöistä sekä niin sanotuista sensibiliteeteistä. Sensibiliteeteillä tarkoitettaan asennoitumista toimintaa kohti. Albrechtin luomien kategorioiden pohjalta laadittiin kyselylomakkeeseen kaksi mittaria. Toinen mittasi koko helluntailaisen spiritualiteetin kenttää kuvaavia perustekijöitä, joihin sisältyivät uskomukset, käytännöt sekä sensibiliteetit. Toinen mittari keskittyi mittaamaan vain yhtä spiritualiteettimääritelmän osaa, sensibiliteettejä. Helluntailaisuuteen painottuvan näkökulman lisäksi tutkimuksessa käytettiin hyväksi David Hayn spiritualiteettinäkemystä. Hän määrittelee spiritualiteetin arkitodellisuuden ylittäväksi tietoisuudeksi. Hayn laatimien kategorioiden avulla kartoitettiin yleisinhimillistä spiritualiteettia. Tutkimuksen tarkoituksena oli selvittää Saalem-seurakunnan spiritualiteetin ilmenemismuotoja ja eroavaisuuksia suhteessa taustoihin. Lisäksi verrattiin Saalemista kerättyä aineistoa vertailuaineistoon (Case Kallio) sekä selvitettiin kahden erilaisesta lähtökohdasta nousevan spiritualitteettinäkemyksen yhteyttä toisiinsa. Tutkimus oli luonteeltaan kvantitatiivinen. Tutkimusmenetelminä käytettiin tilastollisia testejä sekä faktorianalyysiä. Faktorianalyysin rinnalla käytettiin niin kutsutta Bayes-mallinnusta, jolla ei ole parametrisille menetelmille asetettuja tiukkoja käyttöehtoja. Saalem-seurakunnasta tutkimustulokseksi saatiin 11 eritasoista spiritualiteettiulottuvuutta. Albrechtin esittämät seitsemän sensibiliteettikategoriaa löytyivät lähes sellaisenaan aineistosta, kun taas helluntailaisen spiritualiteetin perustekijöiden sekä yleisinhimillisen spiritualiteetin kohdalla käytössä olleet mittarit eivät toimineet täysin odotetulla tavalla. Kahta erilaista aineistoa voitiin vertailla yleisinhimillisen spiritualiteetin osalta. Yleisinhimillinen spiritualiteetti ei ollut vieras ilmiö kristillisestä opista ja hartaudenharjoittamisesta vieraantuneille vastaajille. Kuitenkin se sai korkeampia vastauspistemääriä helluntailaisten parissa. Kyseistä spiritualiteettia eriytyi kuvaamaan kaksi ulottuvuutta: yhteisöllinen altruismi sekä arjen kauneus. Pelkästään Saalem-seurakunnasta kerätystä aineistosta eriytyi lisäksi kolme helluntailaisen spiritualiteetin perustekijää: sana ja missio, johtajakeskeisyys sekä ylistys -ulottuvuudet. Samasta aineistosta nousi kuusi sensibiliteettiulottuvuutta: ylistys,yleinen puhdistuminen, seremoniallisuus, armolahjat, tavoitteellisuus sekä hengellinen puhdistuminen ja muutos. Toinen ylistysulottuvuus kuvasi ylistyksen merkitystä, toinen ylistystapaa. Saalem-seurakunnasta kerätyn aineiston keskiöön asettui sanaa ja missiota kuvaava ulottuvuus. Korkeimman vastauskeskiarvon sai tavoitteellisuusulottuvuus, samoin kuin molemmat yleisinhimillistä spiritualiteettia kuvastaneet ulottuvuudet saivat korkeita vastauskeskiarvoja. Helluntailaisen spiritualiteetin ulottuvuudet korreloivat positiivisesti yleisinhimillisen spiritualiteetin ulottuvuuksien kanssa. Tulokset voitiin yleistää koskemaan Helsingin Saalem-seurakunnan jäsenistöä sekä pääkaupunkiseudun helluntailaisuutta. Koko Suomen helluntailiikkeen kohdalla tuloksia voitiin pitää suuntaa-antavina. Avainsanat: helluntailiike, spiritualiteetti, Saalem, kvantitatiivinen tutkimus, monimuuttujamenetelmät, Bayes-mallinnus, Daniel Albrecht, David Hay

Antiferromagnetic spin-wave states in a linear chain with nearest- and next-nearest-neighbour interactions

The spectrum of short-closed chains up to N=12 are studied by exact diagonalization to obtain the spin-wave spectrum of the Hamiltonian H=2J Sigma i=1Nsi.si+1+2J alpha Sigma i=1Nsi.si+2, -1.0formula obtained by the Anderson approximation (1952). The results of short chains indicate that S=0 bound magnon states lie partly below the spin-wave states with S=1 only for alpha >or=0.3 and alpha

Orbit perturbation theory of beam-plasma instability

The nonlinear theory of the instability caused by an electron beam-plasma interaction is studied. A nonlinear analysis has been carried out using many-body methods. A general formula for a neutral collisionless plasma, without external fields, is derived. This could be used for calculating the saturation levels of other instabilities. The effect of orbit perturbation theory on the beam-plasma instability is briefly reviewed.

Matrices of finite Lorentz transformations in a noncompact basis. III. Completeness relation for O(2, 1)

A parametrization of the elements of the three-dimensional Lorentz group O(2, 1), suited to the use of a noncompact O(1, 1) basis in its unitary representations, is derived and used to set up the representation matrices for the entire group. The Plancherel formula for O(2, 1) is then expressed in this basis.

X-ray crystal structure of a ternary copper(II) vitamin B6 complex, hydroxo(2,2'-bipyridyl)(pyridoxinato) copper(II) monohydrate. A rare example of monodentate coordination of copper(II) by the hydroxyl ion

A ternary metal complex involving Vitamin B6 with the formula [Cu(bipy)(pn) (OH)]H2O (bipy = 2,2'²-bipyridine, PN = anionic pyridoxine) has been synthesized and studied in the solid state by means of spectroscopy and X-ray crystallography. The geometry around copper(II) is distorted square pyramidal, two oxygens from phenolic and 4-(hydroxymethyl) groups of pn, two nitrogens from bipy and an axial OH- ion forming the coordination sphere. In this structure pn exists in a new anionic form with deprotonation of the phenolic group. The structure also provides a rare example of monodentate hydroxyl coordination to copper.

Simplified theory of optical nonlinearities in spin-polarized semiconductors

The spin degree of freedom is largely disregarded in existing theories of the density-dependent optical properties of an interacting electron-hole plasma in quasiequilibrium. Here, we extended the pair equation, which is applicable to a bulk semiconductor at elevated temperatures, to calculate optical nonlinearities due to a spin-polarized plasma. We obtained agreement with recent circular dichroism data in laser-excited GaAs by using the plasma density alone as the fitting parameter. The simplicity of our theory, based on the analytical pair-equation formula, makes it ideal for conveniently modelling absorption in a carrier spin-polarized semiconductor.

Kafka on the Shore

Kafka On The Shore consists of three simple concrete letterforms floating on a gallery wall. Reminiscent of minimalist sculpture, the mathematical expression of the letterforms states that ‘r’ is greater than ‘g’. Despite this material simplicity, the solemn presentation of the formula suggests a sense of foreboding, a quiet menace. The work was created as a response to the economic theories of Thomas Piketty presented in his book Capital in the Twenty-First Century. The primary finding of Piketty’s data-driven research is the formula presented by the work; that historically, wealth and inequity both flourish when the rate of return on capital (r) is greater than the rate of economic growth (g). With this simple mathematical summary the book acts as a sobering indictment on the present state of economic inequality.