Marine environmental design parameter extrapolation has important applications in marine engineering and coastal disaster prevention.The distribution models used for environmental design parameter usually pass the hyp...Marine environmental design parameter extrapolation has important applications in marine engineering and coastal disaster prevention.The distribution models used for environmental design parameter usually pass the hypothesis tests in statistical analysis,but the calculation results of different distribution models often vary largely.In this paper,based on the information entropy,the overall uncertainty test criteria were studied for commonly used distributions including Gumbel,Weibull,and Pearson-III distribution.An improved method for parameter estimation of the maximum entropy distribution model is proposed on the basis of moment estimation.The study in this paper shows that the number of sample data and the degree of dispersion are proportional to the information entropy,and the overall uncertainty of the maximum entropy distribution model is minimal compared with other models.展开更多
In this paper, we establish a generalized extreme Value-Pareto distribution model and derive an analytical expression of Weibull–Pareto distribution model. Based on a data sample of 26-year wave height, we adopt the ...In this paper, we establish a generalized extreme Value-Pareto distribution model and derive an analytical expression of Weibull–Pareto distribution model. Based on a data sample of 26-year wave height, we adopt the new model to estimate the design wave height for 500, 700 and 1000-year return periods. Results show that the design wave height from Weibull–Pareto distribution is between that of the Weibull distribution and that of the Pearson-Ⅲ distribution.For the 500-year return period design wave height, the results from the new model is 1.601% lower than those from the Weibull distribution and 1.319% higher than those from the Pearson-Ⅲ distribution. The Weibull–Pareto distribution innovatively considers the fractal features, extreme-value statistics and the truncated data in the derivation process. Therefore, it is a more holistic and practical model for estimating the design parameters in marine and coastal environments.展开更多
目的研究分析腹腔镜胃癌根治术不同入路方式治疗胃癌的效果。方法选取2017年12月~2021年12月徐州医科大学附属淮安医院胃肠外科收治的48例胃癌患者作为研究对象;依据随机数字表法分为常规手术组(接受左侧后入路腹腔镜胃癌根治术治疗)和...目的研究分析腹腔镜胃癌根治术不同入路方式治疗胃癌的效果。方法选取2017年12月~2021年12月徐州医科大学附属淮安医院胃肠外科收治的48例胃癌患者作为研究对象;依据随机数字表法分为常规手术组(接受左侧后入路腹腔镜胃癌根治术治疗)和观察手术组(接受右侧前入路腹腔镜胃癌根治术治疗),每组24例;统计两组患者的手术时间、术中出血量、首次下床活动时间、住院总时间,分别于手术前后统计两组患者血清的C反应蛋白(C-reactive protein,CRP)、白介素-6(interleukin-6,IL-6)、QLQ-C30生活质量评分(The Quality of Life Questionnaire-Core 30,QLQ-C30)、癌胚抗原(carcinoembryonic antigen,CEA)、多巴胺脱羧酶(dopa decarboxylase,DDC)以及术后切口感染、吻合口瘘、肺部感染的发生率及术后6个月的复发率。结果术前,两组患者的CEA、DDC、IL-6、CRP水平及QLQ-C30评分差异无统计学意义(P>0.05);术后,与常规手术组比较,观察手术组患者的CEA、DDC、CRP、IL-6水平明显更低,其QLQ-C30评分更高,该组患者的并发症发生率及半年内的复发率也低于常规手术组,差异具有统计学意义(P<0.05)。结论与左侧后入路腹腔镜胃癌根治术比较,右侧前入路腹腔镜胃癌根治术能够有效改善患者各项指征,降低术后并发症的发生率,患者的恢复速度更快,复发率更低,优势更加显著。展开更多
基金This research was financially supported by the National Natural Science Foundation of China(Grant Nos.52071306 and 51379195)the Natural Science Foundation of Shandong Province(Grant No.ZR2019MEE050).
文摘Marine environmental design parameter extrapolation has important applications in marine engineering and coastal disaster prevention.The distribution models used for environmental design parameter usually pass the hypothesis tests in statistical analysis,but the calculation results of different distribution models often vary largely.In this paper,based on the information entropy,the overall uncertainty test criteria were studied for commonly used distributions including Gumbel,Weibull,and Pearson-III distribution.An improved method for parameter estimation of the maximum entropy distribution model is proposed on the basis of moment estimation.The study in this paper shows that the number of sample data and the degree of dispersion are proportional to the information entropy,and the overall uncertainty of the maximum entropy distribution model is minimal compared with other models.
基金supported by the NSFC-Shandong Joint Fund(Grant No.U1706226)Graduate Education Reform and Research Fund(Grant No.HDJG18007)
文摘In this paper, we establish a generalized extreme Value-Pareto distribution model and derive an analytical expression of Weibull–Pareto distribution model. Based on a data sample of 26-year wave height, we adopt the new model to estimate the design wave height for 500, 700 and 1000-year return periods. Results show that the design wave height from Weibull–Pareto distribution is between that of the Weibull distribution and that of the Pearson-Ⅲ distribution.For the 500-year return period design wave height, the results from the new model is 1.601% lower than those from the Weibull distribution and 1.319% higher than those from the Pearson-Ⅲ distribution. The Weibull–Pareto distribution innovatively considers the fractal features, extreme-value statistics and the truncated data in the derivation process. Therefore, it is a more holistic and practical model for estimating the design parameters in marine and coastal environments.
文摘目的研究分析腹腔镜胃癌根治术不同入路方式治疗胃癌的效果。方法选取2017年12月~2021年12月徐州医科大学附属淮安医院胃肠外科收治的48例胃癌患者作为研究对象;依据随机数字表法分为常规手术组(接受左侧后入路腹腔镜胃癌根治术治疗)和观察手术组(接受右侧前入路腹腔镜胃癌根治术治疗),每组24例;统计两组患者的手术时间、术中出血量、首次下床活动时间、住院总时间,分别于手术前后统计两组患者血清的C反应蛋白(C-reactive protein,CRP)、白介素-6(interleukin-6,IL-6)、QLQ-C30生活质量评分(The Quality of Life Questionnaire-Core 30,QLQ-C30)、癌胚抗原(carcinoembryonic antigen,CEA)、多巴胺脱羧酶(dopa decarboxylase,DDC)以及术后切口感染、吻合口瘘、肺部感染的发生率及术后6个月的复发率。结果术前,两组患者的CEA、DDC、IL-6、CRP水平及QLQ-C30评分差异无统计学意义(P>0.05);术后,与常规手术组比较,观察手术组患者的CEA、DDC、CRP、IL-6水平明显更低,其QLQ-C30评分更高,该组患者的并发症发生率及半年内的复发率也低于常规手术组,差异具有统计学意义(P<0.05)。结论与左侧后入路腹腔镜胃癌根治术比较,右侧前入路腹腔镜胃癌根治术能够有效改善患者各项指征,降低术后并发症的发生率,患者的恢复速度更快,复发率更低,优势更加显著。
