1,721,062 research outputs found
Studio preliminare per la quantificazione della stimolazione FREMS su pazienti arteriopatici
No full textLa stimolazione FREMS (Frequency Rhythmic Electrical Modulation System) è caratterizzata dall'applicazione di sequenze di impulsi elettrici transcutanei modulati in frequenza e in ampiezza.
Non è ancora nota la “dose” di stimolazione necessaria per avere una risposta clinicamente efficace nei pazienti vasculopatici periferici degli arti inferiori.
Nel presente studio si è cercato di evidenziare quali voltaggi sono stati più efficaci dal punto di vista clinico. In 7 pazienti con ischemia critica arti inferiori non rivascolarizzabile è stata applicata la FREMS oltre alla terapia farmacologica del caso. A fine trattamento in 4 pazienti si è avuto una riduzione della sintomatologia dolorosa a riposo mentre in 3 non si è osservata alcuna variazione clinicamente evidente. Nei 4 pazienti responder si è notata una riduzione significativa del voltaggio medio applicato rispetto ai 3 pazienti non responder (55, 25 ± 21,7 volt vs 82,80 ± 17,64 volt, p value < 0.03) ma non si sono evidenziate variazioni significative dei valori di TCPO2 tra i due gruppi (23.4 mmHg Vs 26,7 mmHg nei non responder)
Un editor intelligente per la costruzione di una base di conoscenza secondo il modello entita' situazione
No full textAtti di: P. Mello, (a cura di). Bologna
Characterization of particle interaction energy through incipient turbulent aggregation
No full textA technique for estimating the particle-particle interaction energy in a colloidal system through incipient aggregation in an isotropic turbulent field is proposed. With this technique, we first determine experimentally the critical (i.e., minimum) energy dissipation rate that induces aggregation in a given stable colloidal system. Then, assuming DLVO interparticle potentials, we can estimate the surface charge and potential by determining the critical relative trajectory of two particles leading to aggregation. It is worth noting that the interparticle interaction potential estimated by this technique accounts in an effective manner also for all the other non-DLVO interparticle interactions that may be present in the system. In other words, using the surface charge value estimated by this technique in the frame of a DLVO model allows us to reproduce correctly the conditions under which the colloidal system was found experimentally to undergo aggregation in a turbulent field. An experimental verification of the proposed technique is shown using a fluorinated polymer latex. It was found that the obtained value of the surface charge is very close to that measured by conductometric titration and is practically constant in the investigated range of particle volume fraction and ionic strength values. (C) 2002 Elsevier Science (USA)
Compliant design for intrinsic safety: general issues and preliminary design
No full textWe describe some initial results of a project aiming at the development of a programmable compliance, inherently safe robot arm for applications in anthropic environments. In order to obtain safety in spite of worst-case situations (such as unexpected delays in teleoperation, or even controller failure), we propose an approach to achieving the compliance by mechanical rather than by control design. We first describe some of the control problems encountered in a typical, large, possibly unknown mechanical compliance, and present the result that shows the possibility to cope with these uncertainties in an adaptive way. Next, we describe the initial development of a new prototype arm under construction in our laboratory. The arm is designed to achieve arbitrary position tracking in 3D with controlled effective compliance at the joint
Description Logics as a core of a tutoring system
No full textA tutorng system based on description logicsDFKI report n. D-94-10
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The Entity/Situation Knowledge Representation System
No full textElsevier Science B.V. (North- Holland
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