408 research outputs found

    A class of superrigid group von Neumann algebras

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    We prove that for any group G in a fairly large class of generalized wreath product groups, the associated von Neumann algebra L(G) completely "remembers" the group G. More precisely, if L(G) is isomorphic to the von Neumann algebra L(\Lambda) of an arbitrary countable group \Lambda, then \Lambda\ must be isomorphic to G. This represents the first superrigidity result pertaining to group von Neumann algebras.Comment: v3: minor changes, final version, to appear in Annals of Mathematics. v2: improved and clarified expositio

    AN INVESTIGATIVE STUDY REGARDING SMES SPECIFIC ACCOUNTING POLICIES

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    In this paper we intend to continue the research regarding the enterprise accounting policies and the manner in which these are perceived by the practitioner accountants, preparers of financial statements. This time, in order to carry out the research, we made up a new questionnaire applied to the same sample, containing a number of 100 SMEs in Bihor County, selected according to the criterion of the average number of employees and that of the level of net turnover at the end of 2008. Continuing previous conducted research we have investigated this time the specific accounting policies of the sampled SMEs from Bihor County and the way these policies are understood by practitioners and implemented in order to prepare financial statements. Surprisingly, we have found that only 93.33% of the respondents agree that the elements presented in the annual financial statements of the entity are evaluated in accordance with the general accounting principles stipulated in Order 3055/2009, according to the accrual accounting. Half of the people interviewed had in view all four qualities of accounting information (intelligibility, relevance, credibility, comparability) in drawing up the annual financial statements, and most of them (56.67%) are not aware of the possibility to use a significance threshold (10%-15%) of the total value of that particular category of assets, liabilities, expenditure, income and results for an as faithful as possible presentation of information in the balance sheet and in the profit and loss account.accounting policies, financial reporting, disclosure, SMEs

    Normalisers of irreducible subfactors

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    We consider normalizers of an infinite index irreducible inclusion Nsubset of or equal toM of II1 factors. Unlike the finite index setting, an inclusion uNu*subset of or equal toN can be strict, forcing us to also investigate the semigroup of one-sided normalizers. We relate these one-sided normalizers of N in M to projections in the basic construction and show that every trace one projection in the relative commutant N′∩left angle bracketM,eNright-pointing angle bracket is of the form u*eNu for some unitary uset membership, variantM with uNu*subset of or equal toN generalizing the finite index situation considered by Pimsner and Popa. We use this to show that each normalizer of a tensor product of irreducible subfactors is a tensor product of normalizers modulo a unitary. We also examine normalizers of infinite index irreducible subfactors arising from subgroup–group inclusions Hsubset of or equal toG. Here the one-sided normalizers arise from appropriate group elements modulo a unitary from L(H). We are also able to identify the finite trace L(H)-bimodules in ℓ2(G) as double cosets which are also finite unions of left cosets

    THE RELEVANCE OF PSYCHOLOGY THEORIES TO FINANCIAL ACCOUNTING

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    Starting from the interest that we have found in psychology sciences in order to understand better the way managers, analysts and last but not least investors behave in the decision making process our study focuses on the link between financial reporting, disclosure policies and investors judgment under uncertainty. The theoretical background describes the rational judgment of investors found in economic utility theories but also looks upon the main cognitive and social psychology for irrational behavior in the decision making process. Our research mainly focuses on measuring the influence of five psychological factors on the irrational behavior of potential investor. We showed that overconfidence occurs when investors overestimate the precision of their private signals and their knowledge about the value of a financial transaction and always remember the successfully times and easily forget the failures. Also, we have pointed out that limited attention is frequently associated with changing in disclosure policies and selfcontrol is negatively related to irrational behavior of investor.psychology theories, financial reporting, disclosure, investor, judgment, decision making process, psychology variables

    On the structural theory of II_1 factors of negatively curved groups, II: Actions by product groups

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    This paper includes a series of structural results for von Neumann algebras arising from measure preserving actions by product groups on probability spaces. Expanding upon the methods used earlier by the first two authors \cite{CS}, we obtain new examples of strongly solid factors as well as von Neumann algebras with unique or no Cartan subalgebra. For instance we show that every II1_1 factor associated with a weakly amenable group in the class S\mathcal S of Ozawa is strongly solid, \cite{OzSolid}. There is also the following product version of this result: any maximal abelian \star-subalgebra of any II1_1 factor associated with a finite product of weakly amenable groups in the class S\mathcal S of Ozawa has an amenable normalizing algebra. Finally, pairing some of these results with cocycle superrigidity results from \cite{IoaCSR}, it follows that compact actions by finite products of lattices in Sp(n,1)Sp(n, 1), n2n \geq2, are virtually WW^*-superrigid.Comment: final versio

    Electrochemistry and magnetism of lithium doped transition metal oxides

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    The physics of transition metal oxides is controlled by the combination and competition of several degrees of freedom, in particular the charge, the spin and the orbital state of the electrons. One important parameter responsible for the physical properties is the density of charge carriers which determines the oxidization state of the transition metal ions. The central objective in this work is the study of transition metal oxides in which the charge carrier density is adjusted and controlled via lithium intercalation/deintercalation using electrochemical methods. Lithium exchange can be achieved with a high degree of accuracy by electrochemical methods. The magnetic properties of various intermediate compounds are studied. Among the materials under study the mixed valent vanadium-oxide multiwall nanotubes represent a potentially technologically relevant material for lithium-ion batteries. Upon electron doping of VOx-NTs, the data confirm a higher number of magnetic V4+ sites. Interestingly, room temperature ferromagnetism evolves after electrochemical intercalation of Li, making VOx-NTs a novel type of self-assembled nanoscaled ferromagnets. The high temperature ferromagnetism was attributed to formation of nanosize interacting ferromagnetic spin clusters around the intercalated Li ions. This behavior was established by a complex experimental study with three different local spin probe techniques, namely, electron spin resonance (ESR), nuclear magnetic resonance (NMR) and muon spin relaxation spectroscopies. Sr2CuO2Br2 was another compound studied in this work. The material exhibits CuO4 layers isostructural to the hole-doped high-Tc superconductor La2-xSr2CuO4. Electron doping is realized by Li-intercalation and superconductivity was found below 9K. Electrochemical treatment hence allows the possibility of studying the electronic phase diagram of LixSr2CuO2Br2, a new electron doped superconductor. The effect of electrochemical lithium doping on the magnetic properties was also studied in tunnel-like alpha-MnO2 nanostructures. Upon lithium intercalation, Mn4+ present in alpha-MnO2 will be reduced to Mn3+, resulting in a Mn mixed valency in this compound. The mixed valency and different possible interactions arising between magnetic spins give a complexity to the magnetic properties of doped alpha-MnO2

    THE BEHAVIOR OF SOME COTTON (GOSSYPIUM HIRSUTUM) GENOTYPES UNDER SANDY SOIL CONDITIONS IN SOUTHERN OLTENIA

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    This study follows the behaviour of seven genotypes of cotton (Gossypium hirsutum), cultivated on the sandy soils of Dăbuleni, with the aim of diversifying the range of plants tolerant to climatic factors in southern Oltenia. Observation of vegetative characteristics such as plant height, number of sympodia, number of flowers in the first decade of flowering and quantitative characteristics such as boll weight, fibre weight, seed weight and number of seeds / plant were the object of the study. Research on cotton plant development was correlated with climatic data recorded by the weather station of Dăbuleni RDSPCS, during the growing season from plant sowing in the field to boll formation. Following the study and showing positive results, The Beli-Lom genotype stood out in terms of flowering yield and fibre percentage, and the Cirpan-539 and Beli-Iskar genotypes had positive vegetative growth yield

    Comparing the energy efficiency of exterior shading by metal slats and mesh screens in an early phase design exercise for an office building in Bucharest

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    An early phase design exercise for shading a South facade of an office building in Bucharest is presented here. The problem to solve is deciding in a simple and quick way (not using the complicated BSDF approach), based strictly on energy-efficiency considerations, between two options in principle: the first, exterior screens, is much cheaper and the send is unmovable horizontal aluminium slats. The tool used to produce the necessary result quantities by building energy simulation is COMFEN 4.1. The conclusion is positive: if aesthetic reasons are ignored, in Bucharest and very likely many other Romanian cities having a quite similar climate, screens can be at least equally effective in saving energy by South facade shading. As they allow a flexible shading strategy (removing them during some months of the heating season), the energy-efficiency realized by having them on throughout the year can be increased further
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