The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high ...The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high mobility and limited transmission range of vehicles, bringing users poor performance. To address this issue, we exploit the combination of both clustering and carry-and-forward schemes in this paper. Our scheme coordinates the cooperation of multiple infrastructures, cluster formation in the same direction and data forwarding of reverse vehicles to facilitate the target vehicle to download large-size content in dark areas. The process of data dissemination and achievable data download volume are then derived and analyzed theoretically. Finally, we conduct extensive simulations to verify the performance of the proposed scheme. Results show significant benefits of the proposed scheme in terms of increasing data download volume and throughput.展开更多
Objective:We carried out a meta-analysis to assess the effectiveness and safety of radiotherapy combined with surgery for gastric cancer.Methods:Randomized Clinical Trials (RCTs) in which radiotherapy (preoperative,in...Objective:We carried out a meta-analysis to assess the effectiveness and safety of radiotherapy combined with surgery for gastric cancer.Methods:Randomized Clinical Trials (RCTs) in which radiotherapy (preoperative,intraoperative and postoperative),was compared with surgery alone in resectable gastric cancer were identified by searching Cochrane Library (Issue 2,2009),PubMed (Jan 1966-Jun 2009),EMBASE (Jan 1974-Jun 2009),Chinese Biomedical Literature Database (Jan 1978-Jun 2009),Chinese Science and Technology Periodicals Database (Jan 1989-Jun 2009),China National Knowledge Infrastructure (Jan 1994-Jun 2009) and Wanfang database (Jan 1997-Jun 2009) in English and Chinese languang.Two researchers assessed the quality of included randomized controlled trials (RCT) extracted data independently.The RevMan 5.0 software was used for meta-analysis.Our researchers assessed the quality of included randomized controlled trials (RCT) extracted data independently.The RevMan 5.0 software was used for meta-analysis.Results:Nine randomized controlled trials of 1 548 patients were selected for meta-analysis.Five randomized controlled trials were related with comparison of preoperative radiotherapy plus surgery with single surgery.Two randomized controlled trials were the comparative studies between surgery plus postoperative and single surgery.The meta-analysis results showed that:(1) compared with surgery alone,preoperative radiotherapy combined with surgery can increase 3 years (OR=1.78;95% CI 1.14-2.78,P=0.01),5 years (OR=1.67;95% CI 1.22-2.29,P=0.001),10 years (OR=1.64;95% CI 1.03-2.60,P=0.04) survival rate and resection rate (OR=2.15;95% CI 1.31-3.54,P=0.003);reduce the of tumor recurrence rate (OR=0.59;95% CI 0.37-0.92,P=0.02) and metastasis rate (OR=0.44;95% CI 0.27-0.73,P=0.001);(2) The tumor recurrent rates (OR=0.19,95% CI 0.03-1.14,P=0.07) and tumor metastasis rate (OR=0.09;95% CI 0.00-1.77,P=0.11) had no difference between single surgery group and peri-operative radiotherapy plus surgery group;(3) Postoperative radiotherapy compared with surgery alone had no significant effects on 1 year (OR=0.83;95% CI 0.60-1.15,P=0.26) and 3 years (OR=0.75;95% CI 0.51-1.11,P=0.15) survival rate compared with single surgery,but the 5-year survival rates (OR=0.57;95% CI 0.34-0.95,P=0.03) of the patients who received surgery alone was higher than those who received combined therapy.No difference of the tumor recurrence rate (OR=0.59;95% CI 0.33-1.05,P=0.07),tumor metestasis rate (OR=0.90;95% CI 0.51-1.59,P=0.71) and anastomotic leak (OR=0.98;95% CI 0.25-3.65,P=0.98) were observed between the two groups.Conclusion:Preoperative radiotherapy combined surgery is more rational and effective than surgery alone of gastric cancer.However,in terms of the clinical effects of perioperarive or postoperative radoiotherapy combined with surgery,much multicenter,largescale,high-quality,double-blind and rigorously designed studies would be needed than currently available in the future.展开更多
Complexity and implementation of design norms in Cameroon required a proven foreign expertise, but nowadays local engineers are mastering modern construction techniques. They are turning to pile foundations to solve t...Complexity and implementation of design norms in Cameroon required a proven foreign expertise, but nowadays local engineers are mastering modern construction techniques. They are turning to pile foundations to solve the problem of construction sites on weak soils. The objective of this work is to present the trend of the country pile-driving capacity of some foundations design and construction companies. The proposed analytical method is based on Finite Element Method and on the theory of wave＇s propagation and transmission along the pile taking into account experimental data on the construction site. The proposed method is validated through recorded data during the construction of the Mungo Bridge in Cameroon, and obtained analytical results are in agreement with experimental results.展开更多
The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Afri...The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Africa. Usingdata from World Development Indicators database we conducted panel data analysis for the period of 1990-2014.Empirical results show that labor force, industrialization, foreign direct investment, and exchange rate have positiveimpact on export value. On the other hand, inflation has negative impact on export performance while GDP growthis the only variable that does not affect the export value of East Africa countries. Finally, we suggest somerecommendations, including the need of replacing agricultural exports by the industrial export, improving infrastructural facility as well as the quality of human capital and the need of policies for attracting internationalinvestors.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61571350Key Research and Development Program of Shaanxi(Contract No.2017KW-004,2017ZDXM-GY-022)the 111 Project(B08038)
文摘The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high mobility and limited transmission range of vehicles, bringing users poor performance. To address this issue, we exploit the combination of both clustering and carry-and-forward schemes in this paper. Our scheme coordinates the cooperation of multiple infrastructures, cluster formation in the same direction and data forwarding of reverse vehicles to facilitate the target vehicle to download large-size content in dark areas. The process of data dissemination and achievable data download volume are then derived and analyzed theoretically. Finally, we conduct extensive simulations to verify the performance of the proposed scheme. Results show significant benefits of the proposed scheme in terms of increasing data download volume and throughput.
文摘Objective:We carried out a meta-analysis to assess the effectiveness and safety of radiotherapy combined with surgery for gastric cancer.Methods:Randomized Clinical Trials (RCTs) in which radiotherapy (preoperative,intraoperative and postoperative),was compared with surgery alone in resectable gastric cancer were identified by searching Cochrane Library (Issue 2,2009),PubMed (Jan 1966-Jun 2009),EMBASE (Jan 1974-Jun 2009),Chinese Biomedical Literature Database (Jan 1978-Jun 2009),Chinese Science and Technology Periodicals Database (Jan 1989-Jun 2009),China National Knowledge Infrastructure (Jan 1994-Jun 2009) and Wanfang database (Jan 1997-Jun 2009) in English and Chinese languang.Two researchers assessed the quality of included randomized controlled trials (RCT) extracted data independently.The RevMan 5.0 software was used for meta-analysis.Our researchers assessed the quality of included randomized controlled trials (RCT) extracted data independently.The RevMan 5.0 software was used for meta-analysis.Results:Nine randomized controlled trials of 1 548 patients were selected for meta-analysis.Five randomized controlled trials were related with comparison of preoperative radiotherapy plus surgery with single surgery.Two randomized controlled trials were the comparative studies between surgery plus postoperative and single surgery.The meta-analysis results showed that:(1) compared with surgery alone,preoperative radiotherapy combined with surgery can increase 3 years (OR=1.78;95% CI 1.14-2.78,P=0.01),5 years (OR=1.67;95% CI 1.22-2.29,P=0.001),10 years (OR=1.64;95% CI 1.03-2.60,P=0.04) survival rate and resection rate (OR=2.15;95% CI 1.31-3.54,P=0.003);reduce the of tumor recurrence rate (OR=0.59;95% CI 0.37-0.92,P=0.02) and metastasis rate (OR=0.44;95% CI 0.27-0.73,P=0.001);(2) The tumor recurrent rates (OR=0.19,95% CI 0.03-1.14,P=0.07) and tumor metastasis rate (OR=0.09;95% CI 0.00-1.77,P=0.11) had no difference between single surgery group and peri-operative radiotherapy plus surgery group;(3) Postoperative radiotherapy compared with surgery alone had no significant effects on 1 year (OR=0.83;95% CI 0.60-1.15,P=0.26) and 3 years (OR=0.75;95% CI 0.51-1.11,P=0.15) survival rate compared with single surgery,but the 5-year survival rates (OR=0.57;95% CI 0.34-0.95,P=0.03) of the patients who received surgery alone was higher than those who received combined therapy.No difference of the tumor recurrence rate (OR=0.59;95% CI 0.33-1.05,P=0.07),tumor metestasis rate (OR=0.90;95% CI 0.51-1.59,P=0.71) and anastomotic leak (OR=0.98;95% CI 0.25-3.65,P=0.98) were observed between the two groups.Conclusion:Preoperative radiotherapy combined surgery is more rational and effective than surgery alone of gastric cancer.However,in terms of the clinical effects of perioperarive or postoperative radoiotherapy combined with surgery,much multicenter,largescale,high-quality,double-blind and rigorously designed studies would be needed than currently available in the future.
文摘Complexity and implementation of design norms in Cameroon required a proven foreign expertise, but nowadays local engineers are mastering modern construction techniques. They are turning to pile foundations to solve the problem of construction sites on weak soils. The objective of this work is to present the trend of the country pile-driving capacity of some foundations design and construction companies. The proposed analytical method is based on Finite Element Method and on the theory of wave＇s propagation and transmission along the pile taking into account experimental data on the construction site. The proposed method is validated through recorded data during the construction of the Mungo Bridge in Cameroon, and obtained analytical results are in agreement with experimental results.
文摘The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Africa. Usingdata from World Development Indicators database we conducted panel data analysis for the period of 1990-2014.Empirical results show that labor force, industrialization, foreign direct investment, and exchange rate have positiveimpact on export value. On the other hand, inflation has negative impact on export performance while GDP growthis the only variable that does not affect the export value of East Africa countries. Finally, we suggest somerecommendations, including the need of replacing agricultural exports by the industrial export, improving infrastructural facility as well as the quality of human capital and the need of policies for attracting internationalinvestors.
