Celebrated Econometricians: Katarina Juselius and Soren Johansen

This Special Issue collects contributions related to the advances in the theory and practice of Econometrics induced by the research of Katarina Juselius and Søren Johansen, whom this Special Issue aims to celebrate [...

Participative ergonomics for the improvement of occupational health and safety in industry: a focus group-based approach

This paper introduces a participative approach to the investigation and promotion of health and safety in industry. The proposed methodology promotes the active participation of the workers in the analysis of consequences and causes of unsafe behaviours that may result in work-related musculoskeletal disorders, accidents, injuries or near-misses. The developed participative technique is the Focus Group with Workers, based on the Fault Tree Analysis method (FGW-FTA). Focus groups are conventionally used by social and behavioural researchers to understand opinions, motivations, attitudes, and mental processes that underlie people behaviours. The innovative procedure in this paper addresses researchers and safety professionals during the focus groups with the workers for the identification of critical risk factors in the workplace. The result is a structured analysis, operated by and with the workers, for the identification of consequences and causes of unsafe behaviours. Finally, the developed methodology addresses the definition of a set of preventive and protective measures, and corrective actions for the improvement of health and safety in the workplace. An experimental study in an Italian boiler manufacturer describes the proposed methodology and the results of the focus groups with the workers. An evaluation questionnaire was elaborated to investigate the workers’ knowledge on occupational health and safety. A second questionnaire was developed to understand the workers’ perception on occupational risks. Each participant was invited to fill in both the questionnaires before and after the focus groups with the workers. The results of the study proved the effectiveness of the developed methodology in improving workers knowledge and perceptions on occupational health and safety

Subsidence monitoring system for offshore applications: technology scouting and feasibility studies

Because of concern about possible impacts of hydrocarbon production activities on coastal-area environments and infrastructures, new hydrocarbon offshore development projects in Italy must submit a monitoring plan to Italian authorities to measure and analyse real-time subsidence evolution. The general geological context, where the main offshore Adriatic fields are located, is represented by young unconsolidated terrigenous sediments. In such geological environments, sea floor subsidence, caused by hydrocarbon extraction, is quite probable. Though many tools are available for subsidence monitoring onshore, few are available for offshore monitoring. To fill the gap ENI (Ente Nazionale Idrocarburi) started a research program, principally in collaboration with three companies, to generate a monitoring system tool to measure seafloor subsidence. The tool, according to ENI design technical-specification, would be a robust long pipeline or cable, with a variable or constant outside diameter (less than or equal to 100 mm) and interval spaced measuring points. The design specifications for the first prototype were: to detect 1 mm altitude variation, to work up to 100 m water depth and investigation length of 3 km. Advanced feasibility studies have been carried out with: Fugro Geoservices B.V. (Netherlands), D'Appolonia (Italy), Agisco (Italy). Five design (using three fundamental measurements concepts and five measurement tools) were explored: cable shape changes measured by cable strain using fiber optics (Fugro); cable inclination measured using tiltmeters (D'Appolonia) and measured using fiber optics (Fugro); and internal cable altitude-dependent pressure changes measured using fiber optics (Fugro) and measured using pressure transducers at discrete intervals along the hydraulic system (Agisco). Each design tool was analysed and a rank ordering of preferences was performed. The third method (measurement of pressure changes), with the solution proposed by Agisco, was deemed most feasible. Agisco is building the first prototype of the tool to be installed in an offshore field in the next few years. This paper describes design of instruments from the three companies to satisfy the design specification

growth performance and stress response of common sole subjected to varying stocking densities and rearing temperatures

AbstractEarlier short-term studies have shown productivity of intensively farmed common sole (S. solea) to be closely dependent on rearing density. Irrespective of fish size, elevating crowding conditions led to declining growth rates while the effect of density on mortality remains controversial. To what extent water temperature could affect productivity of growing sole subjected to varying crowding conditions, warrants investigation as very few studies have tried to quantify the effects of this fundamental rearing parameter on growth and survival in this fish species. This is particularly crucial for developing suitable farming protocols in Italy, where common sole may experience a broad range of water temperatures throughout the rearing cycle. The aim of this study was to evaluate productivity and blood cortisol level as a measure of stress response, in growing sole subjected to different stocking densities and temperature conditions. Six hundred juveniles (ind. weight 21.8±1.5g) were randomly allotted..

Relativistic description of electron scattering on the deuteron

Within a quasipotential framework a relativistic analysis is presented of the deuteron current. Assuming that the singularities from the nucleon propagators are important, a so-called equal time approximation of the current is constructed. This is applied to both elastic and inelastic electron scattering. As dynamical model the relativistic one boson exchange model is used. Reasonable agreement is found with a previous relativistic calculation of the elastic electromagnetic form factors of the deuteron. For the unpolarized inelastic electron scattering effects of final state interactions and relativistic corrections to the structure functions are considered in the impulse approximation. Two specific kinematic situations are studied as examples.Comment: (19 pages in revtex + 15 figures not included, available upon request.) report THU-93-10

H^s versus C^0-weighted minimizers

We study a class of semi-linear problems involving the fractional Laplacian under subcritical or critical growth assumptions. We prove that, for the corresponding functional, local minimizers with respect to a C^0-topology weighted with a suitable power of the distance from the boundary are actually local minimizers in the natural H^s-topology.Comment: 15 page