University of Jyväskylä

About: University of Jyväskylä is a education organization based out in Jyvaskyla, Finland. It is known for research contribution in the topics: Population & Neutron. The organization has 8066 authors who have published 25168 publications receiving 725033 citations. The organization is also known as: Jyväskylän yliopisto & Kasvatusopillinen korkeakoulu.

Nuclear matrix elements for 0 ν β β decays with light or heavy Majorana-neutrino exchange

Abstract: We compute the nuclear matrix elements (NMEs) corresponding to the neutrinoless double beta ($0\ensuremath{ u}\ensuremath{\beta}\ensuremath{\beta}$) decays of nuclei which attract current experimental interest. We concentrate on ground-state-to-ground-state decay transitions mediated by light (l-NMEs) or heavy (h-NMEs) Majorana neutrinos. The computations are done in realistic single-particle model spaces using the proton-neutron quasiparticle random-phase approximation (pnQRPA) with two-nucleon interactions based on the Bonn one-boson-exchange $G$ matrix. Both the l-NMEs and the h-NMEs include the appropriate short-range correlations, nucleon form factors, and higher-order nucleonic weak currents. In addition, both types of NMEs are corrected for the isospin symmetry by the recently proposed method in which the particle-particle proton-neutron interaction parameter (${g}_{\mathrm{pp}}$) is decomposed into isoscalar (${g}_{\mathrm{pp}}^{T=0}$) and isovector (${g}_{\mathrm{pp}}^{T=1}$) parts. A detailed analysis of the l-NMEs and the h-NMEs is performed to benchmark our computer code and to compare with other recent calculations which produce h-NMEs that are in tension with each other.

Scale factor local search in differential evolution

Abstract: This paper proposes the scale factor local search differential evolution (SFLSDE). The SFLSDE is a differential evolution (DE) based memetic algorithm which employs, within a self-adaptive scheme, two local search algorithms. These local search algorithms aim at detecting a value of the scale factor corresponding to an offspring with a high performance, while the generation is executed. The local search algorithms thus assist in the global search and generate offspring with high performance which are subsequently supposed to promote the generation of enhanced solutions within the evolutionary framework. Despite its simplicity, the proposed algorithm seems to have very good performance on various test problems. Numerical results are shown in order to justify the use of a double local search instead of a single search. In addition, the SFLSDE has been compared with a standard DE and three other modern DE based metaheuristic for a large and varied set of test problems. Numerical results are given for relatively low and high dimensional cases. A statistical analysis of the optimization results has been included in order to compare the results in terms of final solution detected and convergence speed. The efficiency of the proposed algorithm seems to be very high especially for large scale problems and complex fitness landscapes.

Organizational antecedents and outcomes of job insecurity: a longitudinal study in three organizations in Finland

Abstract: The aim of the study was to examine perceived job insecurity and its organizational antecedents and outcomes within a one-year time period. The study was carried out by means of questionnaires, which were responded to twice, in 1995 (Time 1) and 1996 (Time 2), by employees in three organizations: a factory, a bank, and a municipal social and health care department. The present article is based on the data of those employees (n=210) who participated in the study in both years. The results indicated that perceived job insecurity varied with gender and organization, but not with time. In particular, female employees in the bank reported a high level of job insecurity compared with men. The use of a restorative strategy by management at Time 1 decreased job insecurity at Time 2, whereas job insecurity at Time 1 weakened the quality of human relations and perceived efficiency within the organizations at Time 2. Copyright © 2000 John Wiley & Sons, Ltd.

Effects of combined resistance and cardiovascular training on strength, power, muscle cross-sectional area, and endurance markers in middle-aged men.

Abstract: The effects of a 16-week training period (2 days per week) of resistance training alone (upper- and lower-body extremity exercises) (S), endurance training alone (cycling exercise) (E), or combined resistance (once weekly) and endurance (once weekly) training (SE) on muscle mass, maximal strength (1RM) and power of the leg and arm extensor muscles, maximal workload (Wmax) and submaximal blood lactate accumulation by using an incremental cycling test were examined in middle-aged men [S, n=11, 43 (2) years; E, n=10, 42 (2) years; SE, n=10, 41 (3) years]. During the early phase of training (from week 0 to week 8), the increase 1RM leg strength was similar in both S (22%) and SE (24%) groups, while the increase at week 16 in S (45%) was larger (P<0.05) than that recorded in SE (37%). During the 16-week training period, the increases in power of the leg extensors at 30% and 45% of 1RM were similar in all groups tested. However, the increases in leg power at the loads of 60% and 70% of 1RM at week 16 in S and SE were larger (P<0.05) than those recorded in E, and the increase in power of the arm extensors was larger (P<0.05) in S than in SE (P<0.05) and E (n.s.). No significant differences were observed in the magnitude of the increases in Wmax between E (14%), SE (12%) and E (10%) during the 16-week training period. During the last 8 weeks of training, the increases in Wmax in E and SE were greater (P<0.05–0.01) than that observed in S (n.s.). No significant differences between the groups were observed in the training-induced changes in submaximal blood lactate accumulation. Significant decreases (P<0.05–0.01) in average heart rate were observed after 16 weeks of training in 150 W and 180 W in SE and E, whereas no changes were recorded in S. The data indicate that low-frequency combined training of the leg extensors in previously untrained middle-aged men results in a lower maximal leg strength development only after prolonged training, but does not necessarily affect the development of leg muscle power and cardiovascular fitness recorded in the cycling test when compared with either mode of training alone.