Eigenvector-based identification of bipartite subgraphs

We report our experiments in identifying large bipartite subgraphs of simple connected graphs which are based on the sign pattern of eigenvectors belonging to the extremal eigenvalues of different graph matrices: adjacency, signless Laplacian, Laplacian, and normalized Laplacian matrix. We compare the performance of these methods to a local switching algorithm based on the Erdos bound that each graph contains a bipartite subgraph with at least half of its edges. Experiments with one scale-free and three random graph models, which cover a wide range of real-world networks, show that the methods based on the eigenvectors of the normalized Laplacian and the adjacency matrix yield slightly better, but comparable results to the local switching algorithm. We also formulate two edge bipartivity indices based on the former eigenvectors, and observe that the method of iterative removal of edges with maximum bipartivity index until one obtains a bipartite subgraph, yields comparable results to the local switching algorithm, and significantly better results than an analogous method that employs the edge bipartivity index of Estrada and Gomez-Gardenes.Comment: 20 pages, 8 figure

The effect of Turbulence Models on Numerical Prediction of Air Flow within Street Canyons

November 15-17, Belgrad

Importance of the management incentives for the improvement of company’s activities

In this paper we have emphasized on the importance of the management incentives and their impact on company’s efficiency and effectiveness of corporate governance. Company owners, who regard managerial incentives as an investment rather than as a financial outlay, could expect a commitment of the managers to the interests of the company, achievement of desired results and business prosperity. At the same time, the potential conflict of interests between company’s shareholders and management could be solved by allocation of appropriate management incentives. As the effectiveness of management incentives depends on their good evaluation, it is important to identify potential indicators and to measure their consistency with the value created to business owners. Moreover we have identified financial measures for manager’s contribution to the company operations, used as a criterion for entitlement to managers’ incentives. Paper ends by assessing the need to adjust the company to changing global financial environment, with a special reference to the changes of incentives’ policy in Serbian companies, and the most important motivational factors affecting Romanian employees during the current period of global financial crisis.Management Incentives, Principal-Agent Problem, Incentive Schemes, Company Performance

HUMAN CAPITAL AND SUSTAINABILITY OF RURAL DEVELOPMENT

The strategies and policies of agricultural and rural development, within the overall long-term area development, traditionally lean on natural-resource capital and certain differential-rent advantages. New dimensions of the agricultural and rural multifunctionality of areas in the zones of large industrial and urban agglomerations and the inevitable processes of degradation of natural capital, stress the role of science in the process of sustaining the level of overall production potential. This presumes a certain degree of substitution of natural capital with human, primarily intellectual capital. This is the basis for considering the creating possibilities and transfer methods for new scientific knowledge, in the function of reaching a strategic developmental goal – long-term sustainability of the agricultural and rural development of a certain agroecological or economic- geographical region.Resources, Capital substitution, Role of science, Sustainability of development, Agribusiness, Community/Rural/Urban Development, Labor and Human Capital,

Mass transfer in corrugated-plate membrane modules. II. Ultrafiltration experiments

The application of corrugations as turbulence promoters in membrane filtration was studied. In ultrafiltration experiments with polysulfone membranes using Dextran T70 as solute, it was found that the corrugations result in reduced energy consumption or pressure drop compared with flat membranes at a given value of the flux through the membrane. There appears to be an optimal mutual distance between the corrugations

Itseohjautuvuuden sosiaalinen rakentaminen

Kirjoitus on osa "Elämän peruskysymykset – Anssi Peräkylän 60-vuotisjuhlakirja" -kirja