Home About us Contact
|
Home About us Contact | ||
|
|
||
Same Authors (same + author)
Selected AbstractsModelling and design considerations on CML gates under high-current effectsINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 6 2005M. Alioto Abstract In this paper, the effect of the transit time degradation of bipolar transistors on the power-delay trade-off in CML gates and their design is dealt with. A delay model which accounts for the transit time increase due to the high bias current values used in high-speed applications is derived by generalizing an approach previously proposed by the same authors (IEEE Trans. CAD 1999; 18(9):1369,1375; Model and Design of Bipolar and MOS Current,Mode Logic (CML, ECL and SCL Digital Circuits), Kluwer Academic Publisher: Dordrecht, 2005). The resulting closed-form delay expression is achieved by properly simplifying the SPICE model, and has an explicit dependence on the bias current which determines the power consumption of CML gates. Accordingly, the delay model is used to gain insight into the power-delay trade-off by considering the effect of the transit time degradation in high-speed designs. In particular, the cases where such effects can be neglected are identified, to better understand how the transit time degradation affects the performance of CML gates for current bipolar technologies. The proposed model has a simple and compact expression, thus it turns out to be suitable for pencil-and-paper evaluations, as well as fast timing analysis. Simulations of CML circuits with a 20-GHz bipolar process show that the model has a very good accuracy in a wide range of current and loading conditions. Copyright © 2005 John Wiley & Sons, Ltd. [source] The concept of the gas turbine-based hybrid vehicle: system, design and configuration issuesINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2006Roberto Capata Abstract The object of this study is a theoretical and experimental analysis of a new hybrid propulsion system for a passenger sedan in which the thermal engine is a small gas turbine set. Some preliminary results on the possibility of replacing the conventional ICE of a hybrid ,series' configuration by a turbogas were presented and discussed in previous papers by the same authors: several possible designs were examined under both a thermodynamic and an operative point of view. This paper presents a summary of the project and constitutes an attempt to put things in a proper engineering perspective: the technical feasibility of the project is assessed via a calculation of the required mission loads, a preliminary design of the most important elements of the propulsive system, the choice of the mission control strategy and the implementation of a numerical system simulator. The experiments that provided a verification for the assumed component efficiencies were carried out, in cooperation with the Research Centre of ENEA-Casaccia, on an ELLIOTT TA-45 group. Our results, though only preliminary, allow for a direct comparison between a GT-hybrid vehicle and a modern diesel car, and indicate that the GT-hybrid may be actually a competitor for the FC-powered vehicle concept. Our ,optimal' configuration is a combination of a 100 kg battery pack and two turbogas set of 5 and 16 kW, respectively. Copyright © 2005 John Wiley & Sons, Ltd. [source] The revenge of the Patterson methods.JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2007The Patterson techniques, recently developed by the same authors for the ab initio crystal structure solution of proteins, have been applied to single and multiple anomalous diffraction (SAD and MAD) data to find the substructure of the anomalous scatterers. An automatic procedure has been applied to a large set of test structures, some of which were originally solved with remarkable difficulty. In all cases, the procedure automatically leads to interpretable electron density maps. Patterson techniques have been compared with direct methods; the former seem to be more efficient than the latter, so confirming the results obtained for ab initio phasing, and disproving the common belief that they could only be applied to determine large equal-atom substructures with difficulty. [source] Sinusoidal heart rate pattern: Reappraisal of its definition and clinical significanceJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2004Houchang D. Modanlou Abstract Objectives: To address the clinical significance of sinusoidal heart rate (SHR) pattern and review its occurrence, define its characteristics, and explain its physiopathology. Background: In 1972, Manseau et al. and Kubli et al. described an undulating wave form alternating with a flat or smooth baseline fetal heart rate (FHR) in severely affected, Rh-sensitized and dying fetuses. This FHR pattern was called ,sinusoidal' because of its sine waveform. Subsequently, Modanlou et al. described SHR pattern associated with fetal to maternal hemorrhage causing severe fetal anemia and hydrops fetalis. Both Manseau et al. and Kubli et al. stated that this particular FHR pattern, whatever its pathogenesis, was an extremely significant finding that implied severe fetal jeopardy and impending fetal death. Undulating FHR pattern: Undulating FHR pattern may be due to the following: (1) true SHR pattern; (2) drugs; (3) pre-mortem FHR pattern; (4) pseudo-SHR pattern; and (5) equivocal FHR patterns. Fetal conditions associated with SHR pattern: SHR pattern has been reported with the following fetal conditions: (1) severe fetal anemia of several etiologies; (2) effects of drugs, particularly narcotics; (3) fetal asphyxia/hypoxia; (4) fetal infection; (5) fetal cardiac anomalies; (6) fetal sleep cycles; and (7) sucking and rhythmic movements of fetal mouth. Definition of true SHR pattern: Modanlou and Freeman proposed the following definition for the interpretation of true SHR pattern: (a) stable baseline FHR of 120,160 bpm; (b) amplitude of 5,15 bpm, rarely greater; (c) frequency of 2,5 cycles per minute; (d) fixed or flat short-term variability; (e) oscillation of the sinusoidal wave from above and below a baseline; and (f) no areas of normal FHR variability or reactivity. Physiopathology: Since its early recognition, the physiopathology of SHR became a matter of debate. Murata et al. noted a rise of arginine vasopressin levels in the blood of posthemorrhagic/anemic fetal lamb. Further works by the same authors revealed that with chemical or surgical vagotomy, arginine vasopressin infusion produced SHR pattern, thus providing the role of autonomic nervous system dysfunction combined with the increase in arginine vasopressin as the etiology. Conclusion: SHR is a rare occurrence. A true SHR is an ominous sign of fetal jeopardy needing immediate intervention. The correct diagnosis of true SHR pattern should also include fetal biophysical profile and the absence of drugs such as narcotics. [source] Laparoscopy-assisted distal gastrectomy with systemic lymph node dissection: A phase II study following the learning curveJOURNAL OF SURGICAL ONCOLOGY, Issue 1 2005Michitaka Fujiwara MD Abstract Background and Objectives A preliminary study on the use of laparoscopy-assisted approach to treat gastric carcinoma resulted in higher morbidity. Study Design A prospective phase II study of laparoscopy-assisted distal gastrectomy (LADG) was performed for patients with preoperative diagnosis of T1 N0 stage cancer located in the lower or middle-third stomach. Bleeding amount, operating time, mortality, morbidity, and the number of lymph node retrieval were recorded and compared with the preliminary series reported previously by the same authors. Results Between 2000 and 2002, 47 patients were accrued. The mean blood loss and postoperative hospital stay were significantly decreased compared with the previous series, whereas the operating time was not. There were no in-hospital deaths, with the incidence of anastomotic leakage significantly decreased. All patients remain disease-free to date. Conclusions LADG can be performed safely and morbidity, no longer, is a drawback by experienced hands that have reached plateau of the learning curve, although it remains a time-consuming procedure. Its application to gastric cancer surgery is feasible for early stage cancer, and its applicability to the treatment of T2 stage cancer will be the next issue to be explored. J. Surg. Oncol. 2005;91:26,32. © 2005 Wiley-Liss, Inc. [source] DEFAULTABLE OPTIONS IN A MARKOVIAN INTENSITY MODEL OF CREDIT RISKMATHEMATICAL FINANCE, Issue 4 2008Tomasz R. Bielecki This paper is a follow-up to "Valuation and Hedging of Defaultable Game Options in a Hazard Process Model" by the same authors. In the present paper we give user friendly assumptions ensuring that the general conditions in the previous paper are satisfied. We also give a systematic procedure to construct suitable intensity models of credit risk, and, in the Markovian case, we provide a variational inequality approach to the pre-default pricing problem. We finally illustrate our results on a study of defaultable convertible bonds. [source] Anthropology and Environmental Policy: What Counts?AMERICAN ANTHROPOLOGIST, Issue 3 2010Susan Charnley ABSTRACT, In this article, we call for enhanced quantitative and environmental analysis in the work of environmental anthropologists who wish to influence policy. Using a database of 77 leading monographs published between 1967 and 2006, 147 articles by the same authors, and a separate sample of 137 articles from the journal Human Organization, we document a sharp decline over the last ten years in the collection and use of quantitative and environmental data within environmental anthropology. These declines come at the same time that environmental anthropologists are aiming at greater policy relevance. We use the case of the Polonoroeste Project in the Brazilian Amazon and its impact on World Bank policy as a concrete example of the advantages of fortifying the quantitative and environmental side of our work. We conclude by discussing ways to strengthen environmental anthropology to further enhance its policy relevance and impact. [source] | |||||||||||||