8,808 research outputs found
Integral group ring of the first Mathieu simple group
We investigate the classical Zassenhaus conjecture for the normalized unit group
of the integral group ring of the simple Mathieu group M11. As a consequence, for
this group we confirm the conjecture by Kimmerle about prime graphs
Integral group ring of the McLaughlin simple group
We consider the Zassenhaus conjecture for the normalized unit group of the integral group ring of the McLaughlin sporadic group McL. As a consequence, we confirm for this group the Kimmerle’s conjecture on prime graphs
Kimmerle conjecture for the Held and O'Nan sporadic simple groups
Using the Luthar--Passi method, we investigate the Zassenhaus and
Kimmerle conjectures for normalized unit groups of integral group rings of the
Held and O'Nan sporadic simple groups. We confirm the Kimmerle conjecture for
the Held simple group and also derive for both groups some extra information
relevant to the classical Zassenhaus conjecture
Efficient algorithm for current spectral density calculation in single-electron tunneling and hopping
This write-up describes an efficient numerical method for the Monte Carlo
calculation of the spectral density of current in the multi-junction
single-electron devices and hopping structures. In future we plan to expand
this write-up into a full-size paper.Comment: 4 page
Public works for Poland? Active labour market policies during transition
Following the predominance of macroeconomic stabilisation policies and passive income support schemes in the first phase of transition, active labour market policies (ALMPs) have now come to play a more important role in transition economies. This paper looks at the Polish experience and provides empirical evidence on the effectiveness of ALMPs. We use the Polish Labour Force Survey of August 1994 in combination with its Supplement on the Evaluation of Labour Market Policies together with data on ALMP expenditure at the regional (voivodship) level. The macroeconometric analysis of the relationship between labour market flows and ALMP expenditure shows no significant effects. The microeconometric analysis reveals that ALMPs are not particularly well targeted at the problem groups in the labour market. That is, women and people with basic vocational education do not receive enough attention, whereas persons formerly employed in the public administration seem to have a privileged status in ALMPs. As to the effectiveness of ALMPs, the paper shows that former participants cannot expect to find employment more easily than their peers who have been unemployed but have not been in a programme. Subjective evaluations of former participants also suggest that ALMPs, but especially works programmes, have not increased their chances to find a job. --unemployment,active labour market policies,Poland
Hybrid-DFT+V method for accurate band structure of correlated transition metal compounds: the case of cerium dioxide
Hybrid functionals' non-local exchange-correlation potential contains a
derivative discontinuity that improves on standard semi-local density
functional theory (DFT) band gaps. Moreover, by careful parameterization,
hybrid functionals can provide self-interaction reduced description of selected
states. On the other hand, the uniform description of all the electronic states
of a given system is a know drawback of these functionals that causes varying
accuracy in the description of states with different degrees of localization.
This limitation can be remedied by the orbital dependent exact exchange
extension of hybrid functionals; the hybrid-DFT+V method [V. Iv{\'a}dy, et
al., Phys. Rev. B 90, 035146 (2014)]. Based on the analogy of quasi-particle
equations and hybrid-DFT single particle equations, here we demonstrate that
parameters of hybrid-DFT+V functional can be determined from approximate
quasi-particle spectra. The proposed technique leads to a reduction of
self-interaction and provides improved description for both / and /
-electrons of the simulated system. The performance of our charge
self-consistent method is illustrated on the electronic structure calculation
of cerium dioxide where good agreement with both quasi-particle and
experimental spectra is achieved
A Community-Based Parenting Program with Low-Income Mothers of Young Children
Research has established a significant relationship between certain parental characteristics. such as income or parenting practices, and the development of child behavior problems. This study evaluated the effectiveness of a parenting program for low-income parents of children one to five years old which was offered through community-based family resource centers. Seventy-one mothers completed the program and showed significant decreases in their use of verbal and corporal punishment and significant increases in nurturing behaviors: their children’s behavior also improved significantly. Forty-five percent of parents also met Jacobson and Truax’s (1991) criteria for clinically significant change. Implications for practitioners working With this challenging population are discussed
Diffractive optics approach towards subwavelength pixels
Pixel size in cameras and other refractive imaging devices is typically
limited by the free-space diffraction. However, a vast majority of
semiconductor-based detectors are based on materials with substantially high
refractive index. We demonstrate that diffractive optics can be used to take
advantage of this high refractive index to reduce effective pixel size of the
sensors below free-space diffraction limit. At the same time, diffractive
systems encode both amplitude and phase information about the incoming beam
into multiple pixels, offering the platform for noise-tolerant imaging with
dynamical refocusing. We explore the opportunities opened by high index
diffractive optics to reduce sensor size and increase signal-to-noise ratio of
imaging structures.Comment: submitted to SPIE-DCS 201
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