Cognitive radio has become an effective theory to solve the inefficiency of the spectrum usage. One of the main requirements of cognitive radio systems is the ability to reliably detect the spectrum hole. Previous wor...Cognitive radio has become an effective theory to solve the inefficiency of the spectrum usage. One of the main requirements of cognitive radio systems is the ability to reliably detect the spectrum hole. Previous works on the problem of detection for cognitive radio have suggested the necessity of user cooperation to enable the detection at the low signal-to-noise ratios experienced in practical situations. This paper introduces energy sensing and the cooperative sensing techniques: AND model, OR model, counting model, double threshold model, likelihood ratio model, linear cooperation model and DWCS model. It is proved that significant cooperative gain can be achieved by the proposed models in reducing interference and improving spectrum usage.展开更多
In recent years,a wide range of gastrointestinal endoscopy techniques have been developed,such as endoscopic submucosal dissection(ESD)and endoscopic retrograde cholangiopancreatography(ERCP).Although ESD and ERCP hav...In recent years,a wide range of gastrointestinal endoscopy techniques have been developed,such as endoscopic submucosal dissection(ESD)and endoscopic retrograde cholangiopancreatography(ERCP).Although ESD and ERCP have an important role in gastrointestinal and biliary diseases,each technique has its limitations.Hybrid techniques that combine endoscopic and surgical procedures have emerged that have the advantages of different procedures and negate their limitations at the same time.Laparoscopic endoscopic cooperative surgery and modified laparoscopic endoscopic cooperative surgery combine ESD and laparoscopic techniques to resect submucosal tumors with minimum resection area.Air leak test by intraoperative endoscopy can effectively identify a mechanically insufficient anastomosis and decrease the complication rate.The rendezvous technique that combines percutaneous transhepatic biliary drainage and endoscopy can be performed as a rescue approach for the treatment of biliary obstruction,stenosis and bile duct injuries.For patients with simultaneous presence of stones in the gallbladder and the common bile duct,the laparoendoscopic rendezvous technique can perform ERCP and laparoscopic cholecystectomy at the same time and reduces the risk of pancreatic injury caused by ERCP.Biliobiliary and bilioenteric anastomosis using magnetic compression anastomosis is another choice for biliary obstruction.The most common used approach to deliver the magnets is by percutaneous-peroral tract.Laparoscopicassisted ERCP is a safe and highly effective therapy for patients who develop biliary diseases after Roux-en-Y gastric bypass surgery.展开更多
基金supported by the National High Technology Research and Development Program of China ("863" Program) under Grant No. 2007AA01Z289the National Natural Science Foundation of China under Grant No. 2007CB310608.
文摘Cognitive radio has become an effective theory to solve the inefficiency of the spectrum usage. One of the main requirements of cognitive radio systems is the ability to reliably detect the spectrum hole. Previous works on the problem of detection for cognitive radio have suggested the necessity of user cooperation to enable the detection at the low signal-to-noise ratios experienced in practical situations. This paper introduces energy sensing and the cooperative sensing techniques: AND model, OR model, counting model, double threshold model, likelihood ratio model, linear cooperation model and DWCS model. It is proved that significant cooperative gain can be achieved by the proposed models in reducing interference and improving spectrum usage.
基金Supported by Key Research and Development Program of Science and Technology Department of Sichuan Province,No.2018GZ0088.
文摘In recent years,a wide range of gastrointestinal endoscopy techniques have been developed,such as endoscopic submucosal dissection(ESD)and endoscopic retrograde cholangiopancreatography(ERCP).Although ESD and ERCP have an important role in gastrointestinal and biliary diseases,each technique has its limitations.Hybrid techniques that combine endoscopic and surgical procedures have emerged that have the advantages of different procedures and negate their limitations at the same time.Laparoscopic endoscopic cooperative surgery and modified laparoscopic endoscopic cooperative surgery combine ESD and laparoscopic techniques to resect submucosal tumors with minimum resection area.Air leak test by intraoperative endoscopy can effectively identify a mechanically insufficient anastomosis and decrease the complication rate.The rendezvous technique that combines percutaneous transhepatic biliary drainage and endoscopy can be performed as a rescue approach for the treatment of biliary obstruction,stenosis and bile duct injuries.For patients with simultaneous presence of stones in the gallbladder and the common bile duct,the laparoendoscopic rendezvous technique can perform ERCP and laparoscopic cholecystectomy at the same time and reduces the risk of pancreatic injury caused by ERCP.Biliobiliary and bilioenteric anastomosis using magnetic compression anastomosis is another choice for biliary obstruction.The most common used approach to deliver the magnets is by percutaneous-peroral tract.Laparoscopicassisted ERCP is a safe and highly effective therapy for patients who develop biliary diseases after Roux-en-Y gastric bypass surgery.
