Dynamic data packing towards the optimization of QoC and QoS in networked control systems

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.

Acute Care/Trauma Surgeon＇s role in obstetrical/ gynecologic emergencies (The OBCAT Alert)

BACKGROUND:Overwhelming hemorrhage or other intra-abdominal complications may be associated with obstetrical or gynecologic(OB/GYN) procedures and may require the surgical training of an Acute Care/Trauma Surgeon.The OB Critical Assessment Team(OBCAT Alert) was developed at our institution to facilitate a multidisciplinary response to complex OB/GYN cases.We sought to review and characterize the Acute Care/Trauma Surgeon's role in these cases.METHODS:We conducted a retrospective review of all emergency consults during an OB/GYN case at our institution from 2008 to 2015.An OBCAT is a hospital based alert system designed to immediately notify OB/GYN,anesthesiology,Acute Care/Trauma,the intensive care unit(ICU),and the blood bank of a potential emergency during an OB/GYN case.RESULTS:There were 7±3 OBCAT alerts/year.Seventeen patients required Acute Care/Trauma surgery intervention for hemorrhage.Thirteen patients required damage control packing during their hospitalization.Blood loss averaged 6.8±5.5 L and patients received a total of 21±14units during deliveries with hemorrhage.There were 17 other surgical interventions not related to hemorrhage;seven of these cases were related to adhesions or intestinal injury.Seven additional cases required evaluation post routine OB/GYN procedure;the most common reason was for severe wound complications.There were three deaths during this study period.CONCLUSION:Emergency OB/GYN cases are associated with high morbidity and may require damage control or other surgical techniques in cases of overwhelming hemorrhage.Acute Care/Trauma Surgeons have a key role in the treatment of these complex cases.

Microstructure and Growth Kinetics of Silicide Coatings for TiAl Alloy

In order to improve the oxidation resistance of Ti Al alloy, silicide coatings were prepared by pack cementation method at 1273, 1323, and 1373 K for 1-3 hours. Scanning electron microscopy（SEM）, energy dispersive spectrometry（EDS） and X-ray diffraction（XRD） were employed to investigate the microstructures and phase constitutions of the coatings. The experimental results show that all silicon deposition coatings have multi-layer structure. The microstructure and composition of silicide coatings strongly depend on siliconizing temperatures. In order to investigate the rate controlling step of pack siliconizing on Ti Al alloy, coating growth kinetics was analyzed by measuring the mass gains per unit area of silicided samples as a function of time and temperature. The results showed that the rate controlling step was gas-phase diffusion step and the growth rate constant（k） ranged from 1.53 mg^2/（cm^4·h^2） to 2.3 mg^2/（cm^4·h^2）. Activation energy（Q） for the process was calculated as 109 k J/mol, determined by Arrhenius＇ equation： k = k0 exp[–Q/（RT）].