177,649 research outputs found
Application and comparison of three tomographic techniques for detection of decay in trees
No full textThis paper reports application of electric, ultrasonic, and georadar tomography for detection of decay in trees and their comparison with the traditional penetrometer. Their feasibility in arboriculture is also evaluated, critically considering some "open problems." The experiments were carried out in an urban environment on two plane (Platanus hybrida Brot.) trees. Both trees, after felling, showed extensive white rot in the central cylinder. The electric tomography revealed low resistivity zones roughly centered in the trunk. A comparison with the successively cut sections showed a fine correspondence to decayed areas and a strong correspondence between high moisture zones and low resistivity zones. Ultrasonic tomography demonstrated to be a very effective tool for the detection of internal decay, accurately locating the position of the anomalies and estimating their size, shape, and characteristic in terms of mechanical properties. With the georadar technique, the high contrast of electromagnetic impedance measured between the inner decayed section and the outside sound section allowed the detection of the interface between the sound and decayed section of the tree, using radar acquisition in reflection modality. The penetrometer profiles detected the low-resistance areas inside the two trunk
A. Andreotti, F. Delfino , U. De Martinis, R. Procopio, L. Verolino “A field based inverse algorithm for the identification of the lightning return stroke”, Speedam , Ischia 13-16 Giugno 2000 pagg. B4-37 B4-40
No full textA. Andreotti, F. Delfino, U. De Martinis, R. Procopio, L. Verdolino “Ricostruzione della corrente di ritorno associata a fulminazioni nuvola-terreno mediante misure di campo elettromagnetico” L’Energia Elettrica – Volume 78 (2001) – “Ricerche”
No full textA. Andreotti, F. Delfino , U. De Martinis, R. Procopio, L. Verolino “A field based inverse algorithm for the identification of the lightning return stroke”, Speedam , Ischia 13-16 Giugno 2000 pagg. B4-37 B4-40
No full textA. Andreotti, F. Delfino, U. De Martinis, R. Procopio, L. Verdolino “Ricostruzione della corrente di ritorno associata a fulminazioni nuvola-terreno mediante misure di campo elettromagnetico” L’Energia Elettrica – Volume 78 (2001) – “Ricerche”
No full textA. Andreotti, F. Delfino, U. De Martinis, R. Procopio, L. Verdolino “Ricostruzione della corrente di ritorno associata a fulminazioni nuvola-terreno mediante misure di campo elettromagnetico” L’Energia Elettrica – Volume 78 (2001) – “Ricerche”
No full textDoes strict employment protection discourage job creation? Evidence from Croatia
No full textEmployment protection legislation in Croatia is among the most strict in Europe. Firing is difficult and costly, and flexible forms of employment are limited. Is this apparent rigidity reflected-as one would expect based on standard economic theory-in low labor market dynamics? Is job creation low and hiring limited? Is the job security of insiders achieved at the cost of outsiders not being able to enter thelabor market? The author attempts to answer these questions by examining job flows. If the employment protection legislation is binding, then job and worker turnover should be low. He shows that this is indeed the case. Hiring is limited and the average job tenure is very long in Croatia. Job destruction is low, however job creation is still lower. The result is accumulation of unemployment, in large part due to new labor market entrants not being able to find a job. The high degree of job protection also seems to strengthen the bargaining position of insiders and results in relatively high wages. So, wages in Croatia are higher than among its competitors, even after adjusting for productivity. These high labor costs are likely to contribute to limited job creation in existing firms, but also are likely to discourage the entry of-and thus job creation in-new firms. The author presents evidence that firm growth has been indeed limited in Croatia, contributing to the low employment level. The author examines other potential causes of high unemployment in Croatia (the unemployment benefit system, labor taxation, the wage structure, and skill and spatial mismatches). He argues that they do not play a substantial part in accounting for poor labor market outcomes in Croatia. The author concludes that the stringent employment protection legislation is the key labor market institution behind low job creation and high unemployment. Based on this he recommends specific measures aimed at liberalizing the labor market to foster job creation and employment.Labor Management and Relations,Labor Policies,Labor Markets,Environmental Economics&Policies,Trade Finance and Investment,Labor Markets,Labor Management and Relations,Labor Standards,Banks&Banking Reform,Environmental Economics&Policies
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
On the evaluation of mean time between maintenances of circuit breakers fo r industrial plants, (in collab. conG.Carpinelli,A.Piccolo,F.Rossi), I.E.E.E. Trans. on Power Apparatus and Systems n'7, 1984.
No full textOn the evaluation of mean time between maintenances of circuit breakers fo r industrial plants, (in collab. conG.Carpinelli,A.Piccolo,F.Rossi), I.E.E.E. Trans. on Power Apparatus and Systems n'7, 1984.
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