AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify com...AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM.Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.RESULTS:Seven nonrandomized controlled trials studies were included in this analysis.These studies included a total of 847 patients:273 treated with RFA and 574 treated with HR.The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR:0.41,95% CI:0.22-0.90,P=0.008).RFA had a higher rate of local intrahe-patic recurrence compared to HR (OR:4.89,95% CI:1.73-13.87,P=0.003).No differences were found between the two groups with respect to postoperative morbidity and mortality.CONCLUSION:HR was superior to RFA in the treatment of patients with solitary CLM.However,the findings have to be carefully interpreted due to the lower level of evidence.展开更多
In this study, an improved random access(RA) scheme for Machine-to-Machine(M2M) communications is proposed. The improved RA scheme is realized by two steps. First, the improved RA scheme achieves a reasonable resource...In this study, an improved random access(RA) scheme for Machine-to-Machine(M2M) communications is proposed. The improved RA scheme is realized by two steps. First, the improved RA scheme achieves a reasonable resource tradeoff between physical random access channel(PRACH) and physical uplink shared channel(PUSCH). To realize a low-complexity resource allocation between PRACH and PUSCH, a boundary of traffic load is derived to divide the number of active M2 M users(UEs) into multiple intervals. The corresponding resource allocation for these intervals is determined by e NB. Then the resource allocation for other number of UEs can be obtained from the allocation of these intervals with less computation. Second, the access barring on arrival rate of new UEs is introduced in the improved RA scheme to reduce the expected delay. Numerical results show that the proposed improved RA scheme can realize a low-complexity resource allocation between PRACH and PUSCH. Meanwhile, the expected delay can be effectively reduced by access barring on arriving rate of new M2 M UEs.展开更多
The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability ...The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability of a resource to complete a task is described by certain probability,and the objective is to maximize the reward by appropriately assigning available resources to different tasks. This paper is aimed at an important branch of SRA, that is, stochastic SRA(SSRA) for which the probability for resources to complete tasks is also uncertain. Firstly, a general SSRA model with multiple independent uncertain parameters(GSSRA-MIUP) is built to formulate the problem. Then,a scenario-based reformulation which can address multi-source uncertainties is proposed to facilitate the problem-solving process. Secondly, in view of the superiority of the differential evolution algorithm in real-valued optimization, a discrete version of this algorithm was originally proposed and further combined with a specialized local search to create an efficient hybrid optimizer. The hybrid algorithm is compared with the discrete differential evolution algorithm, a pure random sampling method, as well as a restart local search method. Experimental results show that the proposed hybrid optimizer has obvious advantages in solving GSSRA-MIUP problems.展开更多
文摘AIM:To evaluate the comparative therapeutic efficacy of radiofrequency ablation (RFA) and hepatic resection (HR) for solitary colorectal liver metastases (CLM).METHODS:A literature search was performed to identify comparative studies reporting outcomes for both RFA and HR for solitary CLM.Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.RESULTS:Seven nonrandomized controlled trials studies were included in this analysis.These studies included a total of 847 patients:273 treated with RFA and 574 treated with HR.The 5 years overall survival rates in the HR group were significantly better than those in the RFA group (OR:0.41,95% CI:0.22-0.90,P=0.008).RFA had a higher rate of local intrahe-patic recurrence compared to HR (OR:4.89,95% CI:1.73-13.87,P=0.003).No differences were found between the two groups with respect to postoperative morbidity and mortality.CONCLUSION:HR was superior to RFA in the treatment of patients with solitary CLM.However,the findings have to be carefully interpreted due to the lower level of evidence.
基金supported by Key Laboratory of Universal Wireless Communications(Beijing University of Posts and Telecommunications),Ministry of Education,P.R.China,KFKT-2014103)National Science and Technology Major Project of China(No.2013ZX03006001)National Natural Science Foundation of China(61501056)
文摘In this study, an improved random access(RA) scheme for Machine-to-Machine(M2M) communications is proposed. The improved RA scheme is realized by two steps. First, the improved RA scheme achieves a reasonable resource tradeoff between physical random access channel(PRACH) and physical uplink shared channel(PUSCH). To realize a low-complexity resource allocation between PRACH and PUSCH, a boundary of traffic load is derived to divide the number of active M2 M users(UEs) into multiple intervals. The corresponding resource allocation for these intervals is determined by e NB. Then the resource allocation for other number of UEs can be obtained from the allocation of these intervals with less computation. Second, the access barring on arrival rate of new UEs is introduced in the improved RA scheme to reduce the expected delay. Numerical results show that the proposed improved RA scheme can realize a low-complexity resource allocation between PRACH and PUSCH. Meanwhile, the expected delay can be effectively reduced by access barring on arriving rate of new M2 M UEs.
基金supported by the National Natural Science Foundation of China under Grant No.71361130011
文摘The stochastic resource allocation(SRA) problem is an extensive class of combinatorial optimization problems widely existing in complex systems such as communication networks and unmanned systems. In SRA, the ability of a resource to complete a task is described by certain probability,and the objective is to maximize the reward by appropriately assigning available resources to different tasks. This paper is aimed at an important branch of SRA, that is, stochastic SRA(SSRA) for which the probability for resources to complete tasks is also uncertain. Firstly, a general SSRA model with multiple independent uncertain parameters(GSSRA-MIUP) is built to formulate the problem. Then,a scenario-based reformulation which can address multi-source uncertainties is proposed to facilitate the problem-solving process. Secondly, in view of the superiority of the differential evolution algorithm in real-valued optimization, a discrete version of this algorithm was originally proposed and further combined with a specialized local search to create an efficient hybrid optimizer. The hybrid algorithm is compared with the discrete differential evolution algorithm, a pure random sampling method, as well as a restart local search method. Experimental results show that the proposed hybrid optimizer has obvious advantages in solving GSSRA-MIUP problems.
