New directional bat algorithm for continuous optimization problems

Bat algorithm (BA) is a recent optimization algorithm based on swarm intelligence and inspiration from the echolocation behavior of bats. One of the issues in the standard bat algorithm is the premature convergence that can occur due to the low exploration ability of the algorithm under some conditions. To overcome this deficiency, directional echolocation is introduced to the standard bat algorithm to enhance its exploration and exploitation capabilities. In addition to such directional echolocation, three other improvements have been embedded into the standard bat algorithm to enhance its performance. The new proposed approach, namely the directional Bat Algorithm (dBA), has been then tested using several standard and non-standard benchmarks from the CEC’2005 benchmark suite. The performance of dBA has been compared with ten other algorithms and BA variants using non-parametric statistical tests. The statistical test results show the superiority of the directional bat algorithm

Istraživanje dipolnih uzbuda u 89Y ispod gigantske dipolne rezonancije u pogonu ELBE

We have investigated the dipole response of the stable N = 50 nucleus 89Y up to the excitation energy of the giant dipole resonance (GDR) using the bremsstrahlung facility at the ELBE accelerator at the research center Helmholtz-Zentrum DresdenRossendorf. After eliminating background radiation from atomic processes as well as inelastic transitions in the spectra by using statistical methods, the photoabsorption cross section could be deduced from the photon-scattering data. This cross section was combined with that known from (γ, n) experiments. An excess of the cross section relative to a simple Lorentz approximation of the tail of the GDR is found in the energy range from about 6 MeV up to 11 MeV. The comparison with predictions of a quasiparticle-random-phase approximation (QRPA) showed that the corresponding excitations may be caused by an oscillation of the excessive neutrons forming a so-called pygmy dipole resonance (PDR) as it was found for the neighbouring isotones 88Sr and 90Zr.Istraživali smo dipolne rezonancije u stabilnoj jezgri 89Y s N = 50 do energije uzbude giganske dipolne rezonancije (GDR) rabeći sustav za kočno zračenje pri ubrzivaču ELBE u istraživačkom središtu Dresden-Rosendorf. Nakon uklanjanja pozadinskog zračenja od atomskih procesa kao i od neelastičnih prijelaza u spektrima, mogli smo, primjenom statističkih metoda, odrediti fotoapsorpcijske udarne presjeke za podatke o fotonskom raspršenju. Ti su udarni presjeci povezani s onima iz mjerenja (γ, n) reakcija. Našli smo višak u udarnim presjecima u odnosu na jednostavno Lorentzovo približenje u repu GDR, u području energije od oko 6 MeV do 11 MeV. Usporedba s približenjem kvazičestica i slučajnih faza pokazuje na mogućnost da su odgovorne uzbude uzrokovane oscilacijama viška neutrona koji načine tzv. “pigmy” dipolnu rezonanciju, nađenu u susjednim izotonima 88Sr i 90Zr

Istraživanje dipolnih uzbuda u 89Y ispod gigantske dipolne rezonancije u pogonu ELBE

We have investigated the dipole response of the stable N = 50 nucleus 89Y up to the excitation energy of the giant dipole resonance (GDR) using the bremsstrahlung facility at the ELBE accelerator at the research center Helmholtz-Zentrum DresdenRossendorf. After eliminating background radiation from atomic processes as well as inelastic transitions in the spectra by using statistical methods, the photoabsorption cross section could be deduced from the photon-scattering data. This cross section was combined with that known from (γ, n) experiments. An excess of the cross section relative to a simple Lorentz approximation of the tail of the GDR is found in the energy range from about 6 MeV up to 11 MeV. The comparison with predictions of a quasiparticle-random-phase approximation (QRPA) showed that the corresponding excitations may be caused by an oscillation of the excessive neutrons forming a so-called pygmy dipole resonance (PDR) as it was found for the neighbouring isotones 88Sr and 90Zr.Istraživali smo dipolne rezonancije u stabilnoj jezgri 89Y s N = 50 do energije uzbude giganske dipolne rezonancije (GDR) rabeći sustav za kočno zračenje pri ubrzivaču ELBE u istraživačkom središtu Dresden-Rosendorf. Nakon uklanjanja pozadinskog zračenja od atomskih procesa kao i od neelastičnih prijelaza u spektrima, mogli smo, primjenom statističkih metoda, odrediti fotoapsorpcijske udarne presjeke za podatke o fotonskom raspršenju. Ti su udarni presjeci povezani s onima iz mjerenja (γ, n) reakcija. Našli smo višak u udarnim presjecima u odnosu na jednostavno Lorentzovo približenje u repu GDR, u području energije od oko 6 MeV do 11 MeV. Usporedba s približenjem kvazičestica i slučajnih faza pokazuje na mogućnost da su odgovorne uzbude uzrokovane oscilacijama viška neutrona koji načine tzv. “pigmy” dipolnu rezonanciju, nađenu u susjednim izotonima 88Sr i 90Zr

Electric and magnetic dipole strength in Zn 66

The dipole strength of the nuclide Zn66 was studied in photon-scattering experiments using bremsstrahlung produced with electron beams of energies of 7.5 and 13.4 MeV at the γELBE facility as well as using quasimonoenergetic and linearly polarized photon beams of 30 energies within the range of 4.3 to 9.9 MeV at the HIγS facility. A total of 128 J=1 states were identified, among them 9 with 1+ and 86 with 1- assignments. The quasicontinuum of unresolved transitions was included in the analysis of the spectra and the intensities of branching transitions were estimated on the basis of simulations of statistical γ-ray cascades. As a result, the photoabsorption cross section up to the neutron-separation energy was determined and compared with predictions of the statistical reaction model. The experimental M1 strengths from resolved 1+ states are compared with results of large-scale shell-model calculations

Majority-Rule-Based Web Service Selection

Abstract. Determining the appropriate service for a user request is a two step process. Initially, the available services whose description agrees with that of the request service are discovered. Then, the service selection process assists users in choosing the service that better matches their intention. In many practical situations, the responsibility to decide which is the appropriate service is shared among multiple parties, e.g., among the department heads of a university. The standard approach to such a service selection problem, is to discard services which are unanimously inappropriate, and return the rest. However, as the involved parties may have conflicting interests, it is possible that only few services are eliminated, and thus almost all discovered services need to be considered. This work addresses this shortcoming, by enforcing the majority rule: a service is discarded if the majority of the parties find it inappropriate. We formulate the majority-rule-based service selection problem based on the notions of dominance relationship and skyline. Furthermore, we propose an algorithm that (1) returns a more manageable set of services, eliminating many inappropriate ones, and (2) is more efficient that standard skyline techniques.

Ethyl Gallate Displays Elicitor Activities in Tobacco Plants

Alkyl gallates showed elicitor activities on tobacco in both whole plants and cell suspensions. Methyl gallate (MG), ethyl gallate (EG), and propyl gallate (PG) infiltration into tobacco leaves induced hypersensitive reaction-like lesions and topical production of autofluorescent compounds revealed under UV light. When sprayed on tobacco plants at 5 mM, EG promoted upregulation of defense-related genes such as the antimicrobial PR1, beta-1,3-glucanase PR2, Chitinase PR3, and osmotin PR5 target genes. Tobacco BY-2 cells challenged with EG underwent cell death in 48 h, which was significantly reduced in the presence of the protease inhibitor aprotinin. The three alkyl gallates all caused alkalinization of the BY-2 extracellular medium, whereas gallic acid did not trigger any pH variation. Using EGTA or LaCl3, we showed that Ca2+ mobilization occurred in BY-2 cells elicited with EG. Overall, our findings are the first evidence of alkyl gallate elicitor properties with early perception events on the plasma membrane, potential hypersensitive reactions, and PR-related downstream defense responses in tobacco