This paper uses three size metrics,which are collectable during the design phase,to analyze the potentially confounding effect of class size on the associations between object-oriented（OO）metrics and maintainability...This paper uses three size metrics,which are collectable during the design phase,to analyze the potentially confounding effect of class size on the associations between object-oriented（OO）metrics and maintainability.To draw as many general conclusions as possible,the confounding effect of class size is analyzed on 127 C＋＋ systems and 113 Java systems.For each OO metric,the indirect effect that represents the distortion of the association caused by class size and its variance for individual systems is first computed.Then,a statistical meta-analysis technique is used to compute the average indirect effect over all the systems and to determine if it is significantly different from zero.The experimental results show that the confounding effects of class size on the associations between OO metrics and maintainability generally exist,regardless of whatever size metric is used.Therefore,empirical studies validating OO metrics on maintainability should consider class size as a confounding variable.展开更多
A test system of the permeability of broken coal samples mainly consists of a CMT5305 electronic universal test machine, crushed rock compaction containing cylinder and a self-designed seepage circuit, which is compos...A test system of the permeability of broken coal samples mainly consists of a CMT5305 electronic universal test machine, crushed rock compaction containing cylinder and a self-designed seepage circuit, which is composed of a gear pump, a reversing valve, a relief valve and other components. By using the steady penetration method, the permeability and non-Darcy flow β factor of broken coal samples under five different porosity levels were measured, the grain diameters of the coal samples were selected as 2.5-5 mm, 5-10 mm, 10-15 mm, 15-20 mm, 20-25 mm and 2.5-25 ram, respectively. After measuring the permeability under each porosity, the overfall pressure of the relief valve continuously increased until the coal sample was broken down. In this way, the flow type of liquid inside the broken coal samples changed from seepage to pipe flow. The correlation between breakdown pressure gradient （BPG） and porosity was analyzed, and the BPG was compared with the pressure gradient when seepage instability occurred. The results show that, ①the non-Darcy flow β factor was negative before broken coal samples with six kinds of diameters were broken down; ②the BPG of coal samples with a grain size of 2.5-25 mm was lower than that of the others; ③ the BPG of coal samples with a single diameter under the same porosity increased as the grain size increased; ④ the BPG could be fitted by an exponential function with porosity, and the exponent decreased as the grain size increased for coal samples with a single diameter; ⑤ the BPG was slightly less than the seepage instability pressure gradient. The change in liquid flow type from seepage to pipe flow could be regarded as the performance of the seepage instability.展开更多
Objectives:Maker education is a dominant force in education reform and is viewed as a revolutionary way to learn.As innovative pedagogy is continuously explored in the field of nursing,the emerging role of maker educa...Objectives:Maker education is a dominant force in education reform and is viewed as a revolutionary way to learn.As innovative pedagogy is continuously explored in the field of nursing,the emerging role of maker education must be examined.This research aims to build a nursing bachelor education program based on maker education and to evaluate the effectiveness of this program.Methods:Forty volunteer junior students majoring in nursing from a college were the subjects for this quasi-experiment.The training program for nursing students based on maker education was developed and implemented as an additional class for a period of 12 weeks.Before and after the experiment,two measures including the"Williams Creative Scale"and"Current Status Questionnaire of Nursing Students'Learning"were adopted for investigation,and corresponding statistical methods were used for analysis.The degree of satisfaction with this training program was investigated after the experiment.Results:The average scores of creativity,learning interest,cooperative learning skill,scientific research ability,and information attainment of the nursing students after the implementation of maker education all improved.The differences in the above points before and after the experiment were all statistically significant(P<0.05).Most of the students expressed satisfaction with this training program(72.5%were very satisfied,15.0%were partially satisfied,and 12.5%were not satisfied).Conclusion:Implementing the training program based on maker education enhanced student creativity,learning interest,cooperative learning skill,scientific research ability,and information attainment.Comprehensive nursing talents were also cultivated.Our data suggested the importance of improving this program,adopting the method,and pursuing research in nursing education.展开更多
AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed ...AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed for articles on dietary fiber intake and constipation using the terms:constipation,fiber,cellulose,plant extracts,cereals,bran,psyllium,or plantago.References of important articles were searched manually for relevant studies.Articles were eligible for the meta-analysis if they were high-quality RCTs and reported data on stool frequency,stool consistency,treatment success,laxative use and gastrointestinal symptoms.The data were extracted independently by two researchers(Yang J and Wang HP) according to the described selection criteria.Review manager version 5 software was used for analysis and test.Weighted mean difference with 95%CI was used for quantitative data,odds ratio(OR)with 95%CI was used for dichotomous data.Both I2 statistic with a cut-off of ≥ 50% and the χ2 test with a P value < 0.10 were used to define a significant degree of heterogeneity.RESULTS:We searched 1322 potential relevant articles,19 of which were retrieved for further assessment,14 studies were excluded for various reasons,five studies were included in the analysis.Dietary fiber showed significant advantage over placebo in stool frequency(OR = 1.19;95%CI:0.58-1.80,P < 0.05).There was no significant difference in stool consistency,treatment success,laxative use and painful defecation between the two groups.Stool frequency were reported by five RCTs,all results showed either a trend or a significant difference in favor of the treatment group,number of stools per week increased in treatment group than in placebo group(OR = 1.19;95%CI:0.58-1.80,P < 0.05),with no significant heterogeneity among studies(I2= 0,P = 0.77).Four studies evaluated stool consistency,one of them presented outcome in terms of percentage of hard stool,which was different from others,so we included the other three studies for analysis.Two studies reported treatment success.There was significant heterogeneity between the studies(P < 0.1,I2 > 50%).Three studies reported laxative use,quantitative data was shown in one study,and the pooled analysis of the other two studies showed no significant difference between treatment and placebo groups in laxative use(OR = 1.07;95%CI 0.51-2.25),and no heterogeneity was found(P = 0.84,I2= 0).Three studies evaluated painful defecation:one study presented both quantitative and dichotomous data,the other two studies reported quantitative and dichotomous data separately.We used dichotomous data for analysis.CONCLUSION:Dietary fiber intake can obviously increase stool frequency in patients with constipation.It does not obviously improve stool consistency,treatment success,laxative use and painful defecation.展开更多
A series of uniaxial-compression tests were conducted on some granite speci- mens.A multi-channel,high-speed AE signal acquiring and analyzing system was em- ployed to acquire and record the characteristics of AE even...A series of uniaxial-compression tests were conducted on some granite speci- mens.A multi-channel,high-speed AE signal acquiring and analyzing system was em- ployed to acquire and record the characteristics of AE events and demonstrate the tem- poral and spatial distribution of these events during the failure process.The test results show that in the primary stage,many low amplitude AE events are developed rapidly and distributed randomly throughout the entire specimens.In the second stage,the number of AE increases much slower than that in the first stage,while the amplitude of most AE events became greater.Contrarily to the primary stage,AE events clusteres in the middle area of the specimen and distributes vertically conformed to the orientation of compres- sion.The most distinct characteristic of this stage is a vacant gap formed approximately in the central part of the specimen.In the last stage,the number of AE events increases sharply and their magnitude increases accordingly.The final failure location coincidently inhabited the aforementioned gap.The main conclusion is that most macrocracks are de- veloped from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps,and the AE activity usually becomes quite acute before the main rup- ture occurs.展开更多
A fuzzy ARTMAP classifier is adopted for a classification experiment of CBERS-2 imagery. The fundamental theory and processing about the algorithm are first introduced, followed with a land-use classification experime...A fuzzy ARTMAP classifier is adopted for a classification experiment of CBERS-2 imagery. The fundamental theory and processing about the algorithm are first introduced, followed with a land-use classification experiment in Shihezi County on CBERS-2 high resolution imagery. Three classifiers are compared: maximum likelihood classifier (MLC), error back propagation (BP) classifier, and fuzzy ARTMAP classifier. The comparison shows comparably better results for the fuzzy ARTMAP classifier, with overall classification accuracy of 9.9% and 4.6% higher than that of MLC and BP. The results also prove that the fuzzy ARTMAP classifier has better discernment in identifying bare soil on CBERS-2 imagery.展开更多
基金The National Natural Science Foundation of China(No.60425206,60633010)
文摘This paper uses three size metrics,which are collectable during the design phase,to analyze the potentially confounding effect of class size on the associations between object-oriented（OO）metrics and maintainability.To draw as many general conclusions as possible,the confounding effect of class size is analyzed on 127 C＋＋ systems and 113 Java systems.For each OO metric,the indirect effect that represents the distortion of the association caused by class size and its variance for individual systems is first computed.Then,a statistical meta-analysis technique is used to compute the average indirect effect over all the systems and to determine if it is significantly different from zero.The experimental results show that the confounding effects of class size on the associations between OO metrics and maintainability generally exist,regardless of whatever size metric is used.Therefore,empirical studies validating OO metrics on maintainability should consider class size as a confounding variable.
基金Supported by the National Natural Science Foundation of China （50974107） the University Graduate Research and Innovation Project in Jiangsu Province （CXZZI2_0924）+1 种基金 the Applied Basic Research Project of Yancheng Institute of Technology （XKR2010010） the State Key Laboratory Open Foundation of Deep Geomechanics and Underground Engineering of China University of Mining and Technology （SKLGDUEK1014）
文摘A test system of the permeability of broken coal samples mainly consists of a CMT5305 electronic universal test machine, crushed rock compaction containing cylinder and a self-designed seepage circuit, which is composed of a gear pump, a reversing valve, a relief valve and other components. By using the steady penetration method, the permeability and non-Darcy flow β factor of broken coal samples under five different porosity levels were measured, the grain diameters of the coal samples were selected as 2.5-5 mm, 5-10 mm, 10-15 mm, 15-20 mm, 20-25 mm and 2.5-25 ram, respectively. After measuring the permeability under each porosity, the overfall pressure of the relief valve continuously increased until the coal sample was broken down. In this way, the flow type of liquid inside the broken coal samples changed from seepage to pipe flow. The correlation between breakdown pressure gradient （BPG） and porosity was analyzed, and the BPG was compared with the pressure gradient when seepage instability occurred. The results show that, ①the non-Darcy flow β factor was negative before broken coal samples with six kinds of diameters were broken down; ②the BPG of coal samples with a grain size of 2.5-25 mm was lower than that of the others; ③ the BPG of coal samples with a single diameter under the same porosity increased as the grain size increased; ④ the BPG could be fitted by an exponential function with porosity, and the exponent decreased as the grain size increased for coal samples with a single diameter; ⑤ the BPG was slightly less than the seepage instability pressure gradient. The change in liquid flow type from seepage to pipe flow could be regarded as the performance of the seepage instability.
基金This research was supported by the Graduate Education Reform Project of Chengdu University in 2017[Grant number:cdjgy2017011]the Medical Education Research Project of the Medical Education Branch of Chinese Medical Association and the Medical Education Committee of Chinese Higher Education Association in 2016[Grant number:2016B-HL071].
文摘Objectives:Maker education is a dominant force in education reform and is viewed as a revolutionary way to learn.As innovative pedagogy is continuously explored in the field of nursing,the emerging role of maker education must be examined.This research aims to build a nursing bachelor education program based on maker education and to evaluate the effectiveness of this program.Methods:Forty volunteer junior students majoring in nursing from a college were the subjects for this quasi-experiment.The training program for nursing students based on maker education was developed and implemented as an additional class for a period of 12 weeks.Before and after the experiment,two measures including the"Williams Creative Scale"and"Current Status Questionnaire of Nursing Students'Learning"were adopted for investigation,and corresponding statistical methods were used for analysis.The degree of satisfaction with this training program was investigated after the experiment.Results:The average scores of creativity,learning interest,cooperative learning skill,scientific research ability,and information attainment of the nursing students after the implementation of maker education all improved.The differences in the above points before and after the experiment were all statistically significant(P<0.05).Most of the students expressed satisfaction with this training program(72.5%were very satisfied,15.0%were partially satisfied,and 12.5%were not satisfied).Conclusion:Implementing the training program based on maker education enhanced student creativity,learning interest,cooperative learning skill,scientific research ability,and information attainment.Comprehensive nursing talents were also cultivated.Our data suggested the importance of improving this program,adopting the method,and pursuing research in nursing education.
文摘AIM:To investigate the effect of dietary fiber intake on constipation by a meta-analysis of randomized controlled trials(RCTs).METHODS:We searched Ovid MEDLINE(from 1946 to October 2011),Cochrane Library(2011),PubMed for articles on dietary fiber intake and constipation using the terms:constipation,fiber,cellulose,plant extracts,cereals,bran,psyllium,or plantago.References of important articles were searched manually for relevant studies.Articles were eligible for the meta-analysis if they were high-quality RCTs and reported data on stool frequency,stool consistency,treatment success,laxative use and gastrointestinal symptoms.The data were extracted independently by two researchers(Yang J and Wang HP) according to the described selection criteria.Review manager version 5 software was used for analysis and test.Weighted mean difference with 95%CI was used for quantitative data,odds ratio(OR)with 95%CI was used for dichotomous data.Both I2 statistic with a cut-off of ≥ 50% and the χ2 test with a P value < 0.10 were used to define a significant degree of heterogeneity.RESULTS:We searched 1322 potential relevant articles,19 of which were retrieved for further assessment,14 studies were excluded for various reasons,five studies were included in the analysis.Dietary fiber showed significant advantage over placebo in stool frequency(OR = 1.19;95%CI:0.58-1.80,P < 0.05).There was no significant difference in stool consistency,treatment success,laxative use and painful defecation between the two groups.Stool frequency were reported by five RCTs,all results showed either a trend or a significant difference in favor of the treatment group,number of stools per week increased in treatment group than in placebo group(OR = 1.19;95%CI:0.58-1.80,P < 0.05),with no significant heterogeneity among studies(I2= 0,P = 0.77).Four studies evaluated stool consistency,one of them presented outcome in terms of percentage of hard stool,which was different from others,so we included the other three studies for analysis.Two studies reported treatment success.There was significant heterogeneity between the studies(P < 0.1,I2 > 50%).Three studies reported laxative use,quantitative data was shown in one study,and the pooled analysis of the other two studies showed no significant difference between treatment and placebo groups in laxative use(OR = 1.07;95%CI 0.51-2.25),and no heterogeneity was found(P = 0.84,I2= 0).Three studies evaluated painful defecation:one study presented both quantitative and dichotomous data,the other two studies reported quantitative and dichotomous data separately.We used dichotomous data for analysis.CONCLUSION:Dietary fiber intake can obviously increase stool frequency in patients with constipation.It does not obviously improve stool consistency,treatment success,laxative use and painful defecation.
基金the Special Subject of 863 Programm(2007AA06Z107)the Younth Foundation of HPU(Q2008-51)
文摘A series of uniaxial-compression tests were conducted on some granite speci- mens.A multi-channel,high-speed AE signal acquiring and analyzing system was em- ployed to acquire and record the characteristics of AE events and demonstrate the tem- poral and spatial distribution of these events during the failure process.The test results show that in the primary stage,many low amplitude AE events are developed rapidly and distributed randomly throughout the entire specimens.In the second stage,the number of AE increases much slower than that in the first stage,while the amplitude of most AE events became greater.Contrarily to the primary stage,AE events clusteres in the middle area of the specimen and distributes vertically conformed to the orientation of compres- sion.The most distinct characteristic of this stage is a vacant gap formed approximately in the central part of the specimen.In the last stage,the number of AE events increases sharply and their magnitude increases accordingly.The final failure location coincidently inhabited the aforementioned gap.The main conclusion is that most macrocracks are de- veloped from the surrounding microcracks existed earlier and their positions occupy the earlier formed gaps,and the AE activity usually becomes quite acute before the main rup- ture occurs.
基金Supported by the National Social Development Research Program of China (No.2004DE100625).
文摘A fuzzy ARTMAP classifier is adopted for a classification experiment of CBERS-2 imagery. The fundamental theory and processing about the algorithm are first introduced, followed with a land-use classification experiment in Shihezi County on CBERS-2 high resolution imagery. Three classifiers are compared: maximum likelihood classifier (MLC), error back propagation (BP) classifier, and fuzzy ARTMAP classifier. The comparison shows comparably better results for the fuzzy ARTMAP classifier, with overall classification accuracy of 9.9% and 4.6% higher than that of MLC and BP. The results also prove that the fuzzy ARTMAP classifier has better discernment in identifying bare soil on CBERS-2 imagery.
