We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurement...We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurements and the Kalman filter updates with partial packet, the statistical properties of estimator error covariance matrix iteration and stability of the estimator are studied. It is shown that to guarantee the stability of the Kalman filter, the communication network is required to provide for each of the sensor measurements an associated throughput, which captures all the rates of the successive sensor measurements losses. We first investigate a general discrete-time linear system with the observation partitioned into two parts and give sufficient conditions of the stable estimator. Furthermore, we extend the results to a more general case where the observation is partitioned into n parts. The results are illustrated with some simple numerical examples.展开更多
We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scatteri...We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.展开更多
Partial flap loss(skin involved)or fat necrosis following autologous breast reconstruction remains a dreaded postoperative complication despite significant advances in microsurgical techniques.Several strategies have ...Partial flap loss(skin involved)or fat necrosis following autologous breast reconstruction remains a dreaded postoperative complication despite significant advances in microsurgical techniques.Several strategies have been proposed in the preoperative and intraoperative period to prevent this complication ranging from preoperative imaging,intra-operative tissue perfusion assessment,appropriate perforator selection(location and number),maximizing inflow and outflow with additional anastomoses and/or pedicles,and minimizing ischemia time.Postoperative management of partial flap loss(when there is skin involvement)and fat necrosis remains a challenge,with very little published data focusing on classification,timing,and techniques.Early intervention versus close observation may depend on multiple patient factors and the degree or volume of necrosis.Secondary intervention options include hyperbaric oxygen therapy,fat aeration with a needle,liposuction,fat grafting,addition of another flap or implant,depending on the nature of the defect.This review summarizes the current evidence for each of these strategies to help the current surgeon understand their options in preventing and managing patients suffering from partial flap loss.展开更多
基金supported by National Natural Science Foundation of China (No. 60504017)Fok Ying Tong Education Foundation(No. 111066)Program for New Century Excellent Talents in University (No. NCET-04-0982)
文摘We consider the Kalman filtering problem in a networked environment where there are partial or entire packet losses described by a two state Markovian process. Based on random packet arrivals of the sensor measurements and the Kalman filter updates with partial packet, the statistical properties of estimator error covariance matrix iteration and stability of the estimator are studied. It is shown that to guarantee the stability of the Kalman filter, the communication network is required to provide for each of the sensor measurements an associated throughput, which captures all the rates of the successive sensor measurements losses. We first investigate a general discrete-time linear system with the observation partitioned into two parts and give sufficient conditions of the stable estimator. Furthermore, we extend the results to a more general case where the observation is partitioned into n parts. The results are illustrated with some simple numerical examples.
基金supported by the 973 Program (Grant No. 2006CB921603)the 863 Program (Grant No. 2009AA01Z319)+3 种基金the National Natural Science Foundation of China (Grant Nos. 61008012, 11074154, 10934004, 60978018, 60978001, and 60808009)the National Natural Science Foundation of China for Excellent Research Team (Grant No. 60821004)the Natural Science Foundation of Shanxi Province of China (Grant No. 2009011059-2)the New Teacher Fund of the Ministry of Education of China (Grant No. 20101401120004)
文摘We report on the observation of enhanced high-order partial wave scattering from atom atom interaction via changing the temperature of a magneto optical trap in the process of photoassociation. The high-order scattering partial wave is directly manifested through the large signal amplitude of the rovibrational resonance levels of trap-loss spectroscopy from photoassociation.
文摘Partial flap loss(skin involved)or fat necrosis following autologous breast reconstruction remains a dreaded postoperative complication despite significant advances in microsurgical techniques.Several strategies have been proposed in the preoperative and intraoperative period to prevent this complication ranging from preoperative imaging,intra-operative tissue perfusion assessment,appropriate perforator selection(location and number),maximizing inflow and outflow with additional anastomoses and/or pedicles,and minimizing ischemia time.Postoperative management of partial flap loss(when there is skin involvement)and fat necrosis remains a challenge,with very little published data focusing on classification,timing,and techniques.Early intervention versus close observation may depend on multiple patient factors and the degree or volume of necrosis.Secondary intervention options include hyperbaric oxygen therapy,fat aeration with a needle,liposuction,fat grafting,addition of another flap or implant,depending on the nature of the defect.This review summarizes the current evidence for each of these strategies to help the current surgeon understand their options in preventing and managing patients suffering from partial flap loss.
