AIM:To investigate the outcomes of pancreas-sparing duodenectomy(PSD)with regional lymph node dissection vs pancreaticoduodenectomy(PD).METHODS:Between August 2001 and June 2014,228 patients with early-stage ampullary...AIM:To investigate the outcomes of pancreas-sparing duodenectomy(PSD)with regional lymph node dissection vs pancreaticoduodenectomy(PD).METHODS:Between August 2001 and June 2014,228 patients with early-stage ampullary carcinoma(Amp Ca)underwent surgical treatment(PD,n=159;PSD with regional lymph node dissection,n=69).The patients were divided into two groups:the PD group and the PSD group.Propensity scoring methods were used to select patients with similar disease statuses.A total of 138 matched cases,with 69 patients in each group,were included in the final analysis.RESULTS:The median operative time was shorter among the patients in the PSD group(435 min)compared with those in the PD group(481 min,P=0.048).The median blood loss in the PSD group was significantly less than that in the PD group.The median length of hospital stay was shorter for patients in the PSD group vs the PD group.The incidence of pancreatic fistula was higher among patients in the PD group vs the PSD group.The 1-,3-,and 5-year overall survival and disease-free survival rates for patients in the PSD group were 83%,70%,44%and 73%,61%,39%,respectively,and these values were not different than compared with those in the PD group(P=0.625).CONCLUSION:PSD with regional lymph node dissection presents an acceptable morbidity in addition to its advantages over PD.PSD may be a safe and feasible alternative to PD in the treatment of earlystage Amp Ca.展开更多
Warhead power assessment of the anti-ship missile plays a vital role in determining the optimal design of missile, thus having important strategic research significance. However, in the assessment process, expert’s j...Warhead power assessment of the anti-ship missile plays a vital role in determining the optimal design of missile, thus having important strategic research significance. However, in the assessment process, expert’s judgement will directly affect the assessment accuracy. In addition,there are many criteria involved in the missile design alternatives. Some criteria with poor performance may be compensated by other criteria with excellent performance, and then it is impossible to find the truly optimal alternative. Aimed at solving these problems, this paper proposes a synthetical assessment process based on fuzzy hesitant linguistic term set and the Gained and Lost Dominance Score(GLDS) method. In order to improve the assessment accuracy of experts and solve the problem that experts generate different opinions, combined with the advantages of fuzzy hesitant sets and linguistic term sets, the double hierarchy hesitant fuzzy linguistic term sets are used in this paper to improve the accuracy of expert’s judgement. In order to effectively combine expert’s experience with the data of criteria, the evidence theory and entropy weight method are used to transfer the expert’s judgement to the weight. In order to avoid selecting defective alternative of missile design, the GLDS is used to fuse expert information and criteria information. Sensitivity analysis shows that the assessment process has sensitivity to some extent. However, when the fluctuation of expert’s assessment makes the fluctuation of θ in the range of-5% to 5%, the impact on the results is not quite conspicuous. The analysis of calculation result and comparative analysis show that the assessment process proposed in this paper is accurate enough, has great advantage in selecting the current and potential optimal alternative of missile design, and avoids the alternatives with low criteria performance that cannot be compensated by other criteria being selected.展开更多
Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for construct...Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for constructing parsimonious event risk scores combining a stepwise selection of variables with ensemble scores obtained by aggregation of several scores, using several classifiers, bootstrap samples and various modalities of random selection of variables. Selection methods based on a probabilistic model can be used to achieve a stepwise selection for a given classifier such as logistic regression, but not directly for an ensemble classifier constructed by aggregation of several classifiers. Three selection methods are proposed in this framework, two involving a backward selection of the variables based on their coefficients in an ensemble score and the third involving a forward selection of the variables maximizing the AUC. The stepwise selection allows constructing a succession of scores, with the practitioner able to choose which score best fits his needs. These three methods are compared in an application to construct parsimonious short-term event risk scores in chronic HF patients, using as event the composite endpoint of death or hospitalization for worsening HF within 180 days of a visit. Focusing on the fastest method, four scores are constructed, yielding out-of-bag AUCs ranging from 0.81 (26 variables) to 0.76 (2 variables).展开更多
The researches on the assessment of earthquake forecast are reviewed, then the R-value assessment is further developed theoretically in the paper. The results include the arithmetic of the R-values of earthquake occur...The researches on the assessment of earthquake forecast are reviewed, then the R-value assessment is further developed theoretically in the paper. The results include the arithmetic of the R-values of earthquake occurrence under the condition that 'anomaly' occurred or no 'anomaly' occurred respectively, and the relation between the values. The distribution of Rvalue of a forecast method, corresponding to multi-status anomalies being independent each other, is also developed in the paper. The appropriate methods to estimate the R-values and extrapolate the occurrence probability of future earthquakes are also given in the paper.展开更多
An effective rapid assessment technique, called ＂P25 Scoring Method＂, has been developed and tested on 26 different case studies recently, in order to predict the collapse vulnerability of the R/C buildings. After a...An effective rapid assessment technique, called ＂P25 Scoring Method＂, has been developed and tested on 26 different case studies recently, in order to predict the collapse vulnerability of the R/C buildings. After a short description of the approach, the study presents the sensitivity study of the method to the selected structural parameters by considering incremental deviation of the final scores from the base model. Further, the methodology was applied to an additional 100 damaged buildings in order to check the reliability of the method and some necessary modifications have been applied to the algorithm after considering this larger database. The evaluation of the results has been interpreted as a beneficial guidance for local authorities. The risk bands are defined according to the final scores and the effect of changing the band-width has also been studied through a safe but an economical procedure. A satisfactory correlation of the method with real damage states is obtained and a ready-to-use methodology has been introduced for future studies.展开更多
BACKGROUND Although substantial evidence supports the advantages of cold snare polypectomy(CSP)in terms of polypectomy efficacy and reduced postoperative adverse events,few studies have examined the cost differences b...BACKGROUND Although substantial evidence supports the advantages of cold snare polypectomy(CSP)in terms of polypectomy efficacy and reduced postoperative adverse events,few studies have examined the cost differences between CSP and traditional endoscopic mucosal resection(EMR)for the treatment of intestinal polyps.AIM To compare the efficacy-cost of EMR and CSP in the treatment of intestinal polyps.METHODS A total of 100 patients with intestinal polyps were included in the retrospective data of our hospital from April 2022 to May 2023.According to the treatment methods,they were divided into EMR(n=46)group and CSP(n=54)group.The baseline data of the two groups were balanced by 1:1 propensity score matching(PSM),and the cost-effectiveness analysis was performed on the two groups after matching.The recurrence rate of the two groups of patients was followed up for 1 year,and they were divided into recurrence group and non-recurrence group according to whether they recurred.Multivariate logistic regression analysis was used to screen out the influencing factors affecting the recurrence of intestinal polyps after endoscopic resection.RESULTS Significant disparities were observed in the number of polyps and smoking background between the two groups before PSM(P<0.05).Following PSM,the number of polyps and smoking history were well balanced between the EMR and CSP groups.The direct cost incurred by the CSP group was markedly higher than that incurred by the EMR group.Concurrently,the cost-effectiveness ratio in the CSP group was substantially reduced when juxtaposed with that in the EMR group(P<0.05).Upon completion of the 1-year follow-up,the rate of recurrence after endoscopic intestinal polypectomy was 38.00%.Multivariate methods revealed that age≥60 years,male sex,number of polyps≥3,and pathological type of adenoma were risk factors for recurrence after endoscopic intestinal polypectomy(all P<0.05).CONCLUSION CSP was more cost-effective for the treatment of intestinal polyps.An age≥60 years,male sex,having a number of polyps≥3,and pathological type of adenoma are independent influencing factors for recurrence.展开更多
提出T-球形模糊数的减法和除法算子,讨论T-球形模糊数减法和除法算子的性质。提出基于T-球形模糊减法和除法算子的灰色关联分析方法,并将该方法与多准则妥协解排序(vlsekriterijumska optimizacija i kompromisno resenje,VIKOR)方法结...提出T-球形模糊数的减法和除法算子,讨论T-球形模糊数减法和除法算子的性质。提出基于T-球形模糊减法和除法算子的灰色关联分析方法,并将该方法与多准则妥协解排序(vlsekriterijumska optimizacija i kompromisno resenje,VIKOR)方法结合,防止计算过程中T-球形模糊信息的丢失,利用一种新的得分函数完善T-球形模糊数的比较机制。通过实例及对比实验说明所提的基于T-球形模糊减法和除法算子的灰色-VIKOR方法的有效性和优越性,为解决T-球形模糊环境下的多属性决策问题提供新的有效的方法。展开更多
基金Supported by National Natural Science Foundation of China,No.81170453 and No.81301025Tianjin City High School Science and Technology Fund Planning Project,No.20120118
文摘AIM:To investigate the outcomes of pancreas-sparing duodenectomy(PSD)with regional lymph node dissection vs pancreaticoduodenectomy(PD).METHODS:Between August 2001 and June 2014,228 patients with early-stage ampullary carcinoma(Amp Ca)underwent surgical treatment(PD,n=159;PSD with regional lymph node dissection,n=69).The patients were divided into two groups:the PD group and the PSD group.Propensity scoring methods were used to select patients with similar disease statuses.A total of 138 matched cases,with 69 patients in each group,were included in the final analysis.RESULTS:The median operative time was shorter among the patients in the PSD group(435 min)compared with those in the PD group(481 min,P=0.048).The median blood loss in the PSD group was significantly less than that in the PD group.The median length of hospital stay was shorter for patients in the PSD group vs the PD group.The incidence of pancreatic fistula was higher among patients in the PD group vs the PSD group.The 1-,3-,and 5-year overall survival and disease-free survival rates for patients in the PSD group were 83%,70%,44%and 73%,61%,39%,respectively,and these values were not different than compared with those in the PD group(P=0.625).CONCLUSION:PSD with regional lymph node dissection presents an acceptable morbidity in addition to its advantages over PD.PSD may be a safe and feasible alternative to PD in the treatment of earlystage Amp Ca.
文摘Warhead power assessment of the anti-ship missile plays a vital role in determining the optimal design of missile, thus having important strategic research significance. However, in the assessment process, expert’s judgement will directly affect the assessment accuracy. In addition,there are many criteria involved in the missile design alternatives. Some criteria with poor performance may be compensated by other criteria with excellent performance, and then it is impossible to find the truly optimal alternative. Aimed at solving these problems, this paper proposes a synthetical assessment process based on fuzzy hesitant linguistic term set and the Gained and Lost Dominance Score(GLDS) method. In order to improve the assessment accuracy of experts and solve the problem that experts generate different opinions, combined with the advantages of fuzzy hesitant sets and linguistic term sets, the double hierarchy hesitant fuzzy linguistic term sets are used in this paper to improve the accuracy of expert’s judgement. In order to effectively combine expert’s experience with the data of criteria, the evidence theory and entropy weight method are used to transfer the expert’s judgement to the weight. In order to avoid selecting defective alternative of missile design, the GLDS is used to fuse expert information and criteria information. Sensitivity analysis shows that the assessment process has sensitivity to some extent. However, when the fluctuation of expert’s assessment makes the fluctuation of θ in the range of-5% to 5%, the impact on the results is not quite conspicuous. The analysis of calculation result and comparative analysis show that the assessment process proposed in this paper is accurate enough, has great advantage in selecting the current and potential optimal alternative of missile design, and avoids the alternatives with low criteria performance that cannot be compensated by other criteria being selected.
文摘Selecting which explanatory variables to include in a given score is a common difficulty, as a balance must be found between statistical fit and practical application. This article presents a methodology for constructing parsimonious event risk scores combining a stepwise selection of variables with ensemble scores obtained by aggregation of several scores, using several classifiers, bootstrap samples and various modalities of random selection of variables. Selection methods based on a probabilistic model can be used to achieve a stepwise selection for a given classifier such as logistic regression, but not directly for an ensemble classifier constructed by aggregation of several classifiers. Three selection methods are proposed in this framework, two involving a backward selection of the variables based on their coefficients in an ensemble score and the third involving a forward selection of the variables maximizing the AUC. The stepwise selection allows constructing a succession of scores, with the practitioner able to choose which score best fits his needs. These three methods are compared in an application to construct parsimonious short-term event risk scores in chronic HF patients, using as event the composite endpoint of death or hospitalization for worsening HF within 180 days of a visit. Focusing on the fastest method, four scores are constructed, yielding out-of-bag AUCs ranging from 0.81 (26 variables) to 0.76 (2 variables).
基金a result of a project sponsored by the China Seismological Bureau (95-04-07-04-01).
文摘The researches on the assessment of earthquake forecast are reviewed, then the R-value assessment is further developed theoretically in the paper. The results include the arithmetic of the R-values of earthquake occurrence under the condition that 'anomaly' occurred or no 'anomaly' occurred respectively, and the relation between the values. The distribution of Rvalue of a forecast method, corresponding to multi-status anomalies being independent each other, is also developed in the paper. The appropriate methods to estimate the R-values and extrapolate the occurrence probability of future earthquakes are also given in the paper.
文摘An effective rapid assessment technique, called ＂P25 Scoring Method＂, has been developed and tested on 26 different case studies recently, in order to predict the collapse vulnerability of the R/C buildings. After a short description of the approach, the study presents the sensitivity study of the method to the selected structural parameters by considering incremental deviation of the final scores from the base model. Further, the methodology was applied to an additional 100 damaged buildings in order to check the reliability of the method and some necessary modifications have been applied to the algorithm after considering this larger database. The evaluation of the results has been interpreted as a beneficial guidance for local authorities. The risk bands are defined according to the final scores and the effect of changing the band-width has also been studied through a safe but an economical procedure. A satisfactory correlation of the method with real damage states is obtained and a ready-to-use methodology has been introduced for future studies.
文摘BACKGROUND Although substantial evidence supports the advantages of cold snare polypectomy(CSP)in terms of polypectomy efficacy and reduced postoperative adverse events,few studies have examined the cost differences between CSP and traditional endoscopic mucosal resection(EMR)for the treatment of intestinal polyps.AIM To compare the efficacy-cost of EMR and CSP in the treatment of intestinal polyps.METHODS A total of 100 patients with intestinal polyps were included in the retrospective data of our hospital from April 2022 to May 2023.According to the treatment methods,they were divided into EMR(n=46)group and CSP(n=54)group.The baseline data of the two groups were balanced by 1:1 propensity score matching(PSM),and the cost-effectiveness analysis was performed on the two groups after matching.The recurrence rate of the two groups of patients was followed up for 1 year,and they were divided into recurrence group and non-recurrence group according to whether they recurred.Multivariate logistic regression analysis was used to screen out the influencing factors affecting the recurrence of intestinal polyps after endoscopic resection.RESULTS Significant disparities were observed in the number of polyps and smoking background between the two groups before PSM(P<0.05).Following PSM,the number of polyps and smoking history were well balanced between the EMR and CSP groups.The direct cost incurred by the CSP group was markedly higher than that incurred by the EMR group.Concurrently,the cost-effectiveness ratio in the CSP group was substantially reduced when juxtaposed with that in the EMR group(P<0.05).Upon completion of the 1-year follow-up,the rate of recurrence after endoscopic intestinal polypectomy was 38.00%.Multivariate methods revealed that age≥60 years,male sex,number of polyps≥3,and pathological type of adenoma were risk factors for recurrence after endoscopic intestinal polypectomy(all P<0.05).CONCLUSION CSP was more cost-effective for the treatment of intestinal polyps.An age≥60 years,male sex,having a number of polyps≥3,and pathological type of adenoma are independent influencing factors for recurrence.
文摘提出T-球形模糊数的减法和除法算子,讨论T-球形模糊数减法和除法算子的性质。提出基于T-球形模糊减法和除法算子的灰色关联分析方法,并将该方法与多准则妥协解排序(vlsekriterijumska optimizacija i kompromisno resenje,VIKOR)方法结合,防止计算过程中T-球形模糊信息的丢失,利用一种新的得分函数完善T-球形模糊数的比较机制。通过实例及对比实验说明所提的基于T-球形模糊减法和除法算子的灰色-VIKOR方法的有效性和优越性,为解决T-球形模糊环境下的多属性决策问题提供新的有效的方法。
