Javier Martinez | UCC - Academia.edu (original) (raw)
Address: Managua, Managua, Nicaragua
less
Related Authors
Universidad Nacional de Colombia (National University of Colombia)
Uploads
Papers by Javier Martinez
Lancet, 1996
Morbidity and mortality after surgical treatment of bileduct stones increase with age and associa... more Morbidity and mortality after surgical treatment of bileduct stones increase with age and associated diseases. A proposed alternative therapy is endoscopic sphincterotomy (ES) with the gallbladder left in situ, and we elected to compare this option with standard open surgery in high-risk patients. 98 patients (mean age 80 years) with symptoms likely to be due to bileduct stones or a recent episode of biliary pancreatitis were randomised to be treated either by open cholecystectomy with operative cholangiography and (if necessary) bileduct exploration (n=48) or by endoscopic sphincterotomy alone (n=50). The procedure was accomplished successfully in 94% of the surgery group and 88% of the ES group, and there were no significant differences in immediate morbidity (23% vs 16%) or mortality (4% vs 6%). During mean follow-up of 17 months biliary symptoms recurred in three surgical patients, none of whom underwent repeat surgery, and in 10 ES patients, seven of whom had biliary surgery. By multivariate regression analysis endoscopic sphincterotomy was an independent predictor of recurrent biliary symptoms (odds ratio 6.9; 95% Cl 1.46 to 32.54). In elderly or high-risk patients, surgery is preferable to endoscopic sphincterotomy with the gallbladder left in situ as a definitive treatment for bileduct stones or non-severe biliary pancreatitis.
IEEE Transactions on Robotics and Automation, 1995
In this paper we illustrate a compositional method for modeling the concurrent execution of worki... more In this paper we illustrate a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri Nets that we call S 'PI?. In essence, this class is built from state machines sharing a set of places modeling the availability of system resources. The analysis of S ' P R leads us to characterize deadlock situations in terms of a zero marking for some structural objects called siphons. In order to prevent the system from deadlocks, we propose a policy for resource allocation based on the addition of new places to the net imposing restrictions that prevent the presence of unmarked siphons (direct cause of deadlocks). Finally, we present the application of this technique to a realistic FMS case.
Ingenieria de Sistemas e InformAtica ETS de Ingenieros Industriales, Universidad de Zaragoza Mari... more Ingenieria de Sistemas e InformAtica ETS de Ingenieros Industriales, Universidad de Zaragoza Maria Zambrano 50 (Actur), 50015 Zaragoza (Spain) ... Abstract: This paper discusses the design of the coordination subsystem of a Flexible Manufacturing System (FMS) and its ...
Google, Inc. (search). ...
Lancet, 1996
Morbidity and mortality after surgical treatment of bileduct stones increase with age and associa... more Morbidity and mortality after surgical treatment of bileduct stones increase with age and associated diseases. A proposed alternative therapy is endoscopic sphincterotomy (ES) with the gallbladder left in situ, and we elected to compare this option with standard open surgery in high-risk patients. 98 patients (mean age 80 years) with symptoms likely to be due to bileduct stones or a recent episode of biliary pancreatitis were randomised to be treated either by open cholecystectomy with operative cholangiography and (if necessary) bileduct exploration (n=48) or by endoscopic sphincterotomy alone (n=50). The procedure was accomplished successfully in 94% of the surgery group and 88% of the ES group, and there were no significant differences in immediate morbidity (23% vs 16%) or mortality (4% vs 6%). During mean follow-up of 17 months biliary symptoms recurred in three surgical patients, none of whom underwent repeat surgery, and in 10 ES patients, seven of whom had biliary surgery. By multivariate regression analysis endoscopic sphincterotomy was an independent predictor of recurrent biliary symptoms (odds ratio 6.9; 95% Cl 1.46 to 32.54). In elderly or high-risk patients, surgery is preferable to endoscopic sphincterotomy with the gallbladder left in situ as a definitive treatment for bileduct stones or non-severe biliary pancreatitis.
IEEE Transactions on Robotics and Automation, 1995
In this paper we illustrate a compositional method for modeling the concurrent execution of worki... more In this paper we illustrate a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri Nets that we call S 'PI?. In essence, this class is built from state machines sharing a set of places modeling the availability of system resources. The analysis of S ' P R leads us to characterize deadlock situations in terms of a zero marking for some structural objects called siphons. In order to prevent the system from deadlocks, we propose a policy for resource allocation based on the addition of new places to the net imposing restrictions that prevent the presence of unmarked siphons (direct cause of deadlocks). Finally, we present the application of this technique to a realistic FMS case.
Ingenieria de Sistemas e InformAtica ETS de Ingenieros Industriales, Universidad de Zaragoza Mari... more Ingenieria de Sistemas e InformAtica ETS de Ingenieros Industriales, Universidad de Zaragoza Maria Zambrano 50 (Actur), 50015 Zaragoza (Spain) ... Abstract: This paper discusses the design of the coordination subsystem of a Flexible Manufacturing System (FMS) and its ...
Google, Inc. (search). ...