Identification of key recovering node for spatial networks

Many networks in the real world have spatial attributes, such as location of nodes and length of edges, called spatial networks. When these networks are subject to some random or deliberate attacks, some nodes in the network fail, which causes a decline in the network performance. In order to make the network run normally, some of the failed nodes must be recovered. In the case of limited recovery resources, an effective key node identification method can find the key recovering node in the failed nodes, by which the network performance can be recovered most of the failed nodes. We propose two key recovering node identification methods for spatial networks, which are the Euclidean-distance recovery method and the route-length recovery method. Simulations on homogeneous and heterogeneous spatial networks show that the proposed methods can significantly recover the network performance.

A retrospective analysis of the safety and efficacy of low dose tacrolimus (FK506) for living donor liver transplant recipients

We sought to evaluate the efficacy and effects of low-dose tacrolimus （FK506） to recipients with living donor liver transplantation （LDLT）. A total of 66 patients who underwent LDLT between 2001 and 2007 were enrolled in this study. According to different doses of tacrolimus, the recipients were randomly divided into two groups： the low-dose tacrolimus group （group A） and the normal-dose tacrolimus group （group B）. The blood concentration of tacrolimus and its side effects including infection, hyperglycemia, hypertension, high blood creatinine and jaundice were monitored once a week at the perioperative period, and once a month thereafter. Besides, the survival rates of the recipients were analyzed at the 1and 3-year time point after operation. Among these patients, no significant acute rejection was detected after LDLT. The incidences of infection, hyperglycemia, liver dysfunction and renal impairment in group A were markedly lower than those in group B. However, no significant differences were detected in the incidence of hypertension between the two groups. Moreover, the recipients in each group had a similar survival rate according to the results of 1and 3-year follow-up. The incidence of side effects that associated with tacrolimus positively correlated with tacrolimus blood concentration. In conclusion, long-term and low-dose administration of tacrolimus is a safe and effective treatment for LDLT recipients.

Survey of Safety Management Approaches to Unmanned Aerial Vehicles and Enabling Technologies

Unmanned aerial vehicle(UAV)has a rapid development over the last decade.However,an increasing number of severe flight collision events caused by explosive growth of UAV have drawn widespread concern.It is an important issue to investigate safety management approaches of UAVs to ensure safe and efficient operation.In this paper,we present a comprehensive overview of safety management approaches in large,middle and small scales.In large-scale safety management,path-planning problem is a crucial issue to ensure safety and ordered operation of UAVs globally.In middle-scale safety management,it is an important issue to study the conflict detection and resolution methods.And in small-scale safety management,real-time collision avoidance is the last line of ensuring safety.Moreover,a UAV can be regarded as a terminal device connected through communication and information network.Therefore,the enabling technologies,such as sensing,command and control communication,and collaborative decision-making control technology,have been studied in the last.

UAV-Aided Networks for Emergency Communications in Areas with Unevenly Distributed Users

Nowadays,daily human life is closely intertwined with various networks.When natural disasters or malicious attacks break out,the failure of communication infrastructure due to direct destruction or indirect impact tends to cause a massive outage of communications.Emergency communication networks play a significant role in rescue operations.Recently,a flexible and efficient solution has been provided for emergency communications using unmanned aerial vehicles(UAVs).By means of their excellent characteristics,UAVs,serving as aerial base stations(ABSs),can be rapidly deployed to temporarily rebuild a damaged communication network to restore the users’connectivity.In this study,we investigate the use of UAVs as ABSs for an emergency communication scene where user equipment is unevenly distributed and the communication infrastructure has completely failed due to a severe disaster.Effective communication probability(ECP),which integrates throughput coverage and connectivity,is used to evaluate the performance of a communication network.Through simulations,we analyze communication improvements that can be obtained by the flexible deployment of ABSs.The results show a noticeable increase in ECP when some ABSs are deployed in optimal locations.