Based on the theory of moisture vapor permeability and liquid moisture transmission through fabric, this paper is mainly concerned with the wet comfort of the fine denier polypropylene fiber knitted fabrics. The liqui...Based on the theory of moisture vapor permeability and liquid moisture transmission through fabric, this paper is mainly concerned with the wet comfort of the fine denier polypropylene fiber knitted fabrics. The liquid water transport property the liquid water retention property, the moisture permeability property, the moisture releasing and drying property of these fabrics are tested by normal objective ways and discussed. At last, according to these properties these fabries are classified by grey model synthetic evaluation method.展开更多
Accelerated destructive degradation tests(ADDTs)are powerful to provide reliability information in the degradation processes with destructive measurements.In order to carry out an ADDT efficiently,both the estimation ...Accelerated destructive degradation tests(ADDTs)are powerful to provide reliability information in the degradation processes with destructive measurements.In order to carry out an ADDT efficiently,both the estimation precision of parameters and the test cost should be considered.On the basis of the given degradation model and failure criterion,a multiple-objective optimization model for the design of ADDTs is proposed.Under constrains of the maximum measurement time,the total sample size and the number of stress levels,a comprehensive target function is suggested to reflect both the precision of lifetime estimation and total cost,and the optimal test plan is obtained,which is composed by optimal choices for samples size,measurement frequency,and the number of measurements at each stress level.A real example is illustrated to demonstrate the implementation of the proposed approach.展开更多
In this article,I will talk about the definition and discrimination of subjective test and objective test.The strong points and weak points are also discussed.Although each has its own disadvantages,subjective test an...In this article,I will talk about the definition and discrimination of subjective test and objective test.The strong points and weak points are also discussed.Although each has its own disadvantages,subjective test and objective test will still play important roles at present or in future.A good classroom test will usually contain both subjective and objective test items.展开更多
BACKGROUND: Final comprehensive exam is the most important examination for midwifery students to evaluate their professional ability and Test anxiety is a common phenomenon among college students. Because test anxiety...BACKGROUND: Final comprehensive exam is the most important examination for midwifery students to evaluate their professional ability and Test anxiety is a common phenomenon among college students. Because test anxiety is one of the problems of educational systems, this study was performed to compare test anxiety in objective structured clinical examinations (OS-CEs) and traditional assessment methods (TAM) among Undergraduate Midwifery Students. Methods: In this descriptive-analytical study, 52 students of Babol Midwifery College were participated in the study. 20 students were evaluated using TAM in November 2010, and 32 students were evaluated using the OSCE method in July 2011. Data were collected via a two-component questionnaire including demographic data and the test anxiety inventory (TAI). Results: All of midwifery students were women;the mean age of students, ages of father and mother’s were 23.1 ± 0.7, 52.3 ± 3.5 and 47.8 ± 4.9 years, respectively. Most of the students were single (61.5%). The mean education levels of father and mother’s were 11.6 ± 4.5 and 9.9 ± 4.0 years, respectively. The mean score of test anxiety in students was 42.51 ± 13.16. The most of participants did have moderate test anxiety (56.9%), two present not had any test anxiety, 37.3% had low test anxiety, and 3.9% had severe test anxiety. In sum, 98% had some degrees of test anxiety. There were the statistical differences in the mean score of text anxiety in OSCEs Compared with TAM in Undergraduate Midwifery Students (39.38 ± 13.81 vs. 47.35 ± 10.67, P = 0.033). Also, the mean severity of anxiety was different in two groups. The mean of moderate/severe test anxiety was more in TAM compared with OSCEs (52.57% vs. 49.56%, p = 0.000). The test anxiety had a positive correlation with father’s education, mother’s education (0.286, p = 0.042), father’s age, mother’s age, marital status, residency (0.292, p = 0.042). Also, there are negative correlations with student age, satisfaction, total Grade Point Average (GPA) (-0.387, p = 0.007), final score, type of assessment (-0.298, p = 0.033). There is a significant difference between the severity anxiety residency in total (p = 0.10) and OSCEs (p = 0.049) groups, mother’s education in total (p = 0.005) and OSCEs groups (0.012) and GPA (p = 0.028). Conclusion: OSCEs were superior to TAM in the reduction of test anxiety in midwifery students. The prevalence of test anxiety was in TAM than OSCEs method;therefore, using OSCEs is acknowledged as an effective assessment tool and is seen as the gold standard for evaluating clinical performance.展开更多
The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a...The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a criterion of critical importance to software quality. Reusability is an important quality factor to testability. Its early measurement in object oriented software especially at design phase, allows a design to be reapplied to a new problem without much extra effort. This research paper proposes a research framework for quantification process and does an extensive review on reusability of object oriented software. A metrics based model “Reusability Quantification of Object Oriented Design” has been proposed by establishing the relationship among design properties and reusability and justifying the correlation with the help of statistical measures. Also, “Reusability Quantification Model” is empirically validated and contextual significance of the study shows the high correlation for model acceptance. This research paper facilitates to software developers and designer, the inclusion of reusability quantification model to access and quantify software reusability for quality product.展开更多
为解决复合绝缘子污闪抑制与伞裙结构协同优化中电气性能与经济性难以兼顾的难题,本文提出一种基于人工污秽试验数据的污闪预测与多目标优化方法。首先,通过人工污秽试验获取50组污闪电压,构建融合Tent混沌映射与黄金正弦机制的减法平...为解决复合绝缘子污闪抑制与伞裙结构协同优化中电气性能与经济性难以兼顾的难题,本文提出一种基于人工污秽试验数据的污闪预测与多目标优化方法。首先,通过人工污秽试验获取50组污闪电压,构建融合Tent混沌映射与黄金正弦机制的减法平均优化器(golden sine subtraction average based optimizer,GSABO)以优化BP神经网络预测模型。其次,采用二代非支配排序遗传算法(non-dominated sorting genetic algorithm II,NSGA-Ⅱ)建立以污闪电压最大化和硅橡胶用量最小化为目标的优化模型,引入电压-成本比(voltage-cost ratio,UCR)选取Pareto前沿最优解。最后,利用有限元仿真及预测模型双重验证优化后的复合绝缘子的电场分布特性和污闪电压。研究结果表明:GSABO-BP预测模型污闪电压平均相对误差为2.198%(R2=0.9856),优化后目标绝缘子污闪电压提升9.23%,硅橡胶用量降低17.02%;沿面最大场强由2.31 MV/m降至1.92 MV/m,电场不均匀系数降低14.9%。本研究为复合绝缘子伞裙结构设计提供了理论与应用依据。展开更多
机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模...机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模型,结合非支配排序遗传算法(Non-dominated Sorting Genetic Algorithm-Ⅱ,NSGA-Ⅱ)生成Pareto解集,最后采用优劣解距离(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)法决策最优参数组合。结果表明,优化后滑枕质量减少了29.3 kg,较优化前降低了4.7%,最大变形降低了5.8%,一阶固有频率保持稳定在553.3 Hz,表明该方法为机床零/部件多参数耦合优化提供了新的参考。展开更多
文摘Based on the theory of moisture vapor permeability and liquid moisture transmission through fabric, this paper is mainly concerned with the wet comfort of the fine denier polypropylene fiber knitted fabrics. The liquid water transport property the liquid water retention property, the moisture permeability property, the moisture releasing and drying property of these fabrics are tested by normal objective ways and discussed. At last, according to these properties these fabries are classified by grey model synthetic evaluation method.
文摘Accelerated destructive degradation tests(ADDTs)are powerful to provide reliability information in the degradation processes with destructive measurements.In order to carry out an ADDT efficiently,both the estimation precision of parameters and the test cost should be considered.On the basis of the given degradation model and failure criterion,a multiple-objective optimization model for the design of ADDTs is proposed.Under constrains of the maximum measurement time,the total sample size and the number of stress levels,a comprehensive target function is suggested to reflect both the precision of lifetime estimation and total cost,and the optimal test plan is obtained,which is composed by optimal choices for samples size,measurement frequency,and the number of measurements at each stress level.A real example is illustrated to demonstrate the implementation of the proposed approach.
文摘In this article,I will talk about the definition and discrimination of subjective test and objective test.The strong points and weak points are also discussed.Although each has its own disadvantages,subjective test and objective test will still play important roles at present or in future.A good classroom test will usually contain both subjective and objective test items.
文摘BACKGROUND: Final comprehensive exam is the most important examination for midwifery students to evaluate their professional ability and Test anxiety is a common phenomenon among college students. Because test anxiety is one of the problems of educational systems, this study was performed to compare test anxiety in objective structured clinical examinations (OS-CEs) and traditional assessment methods (TAM) among Undergraduate Midwifery Students. Methods: In this descriptive-analytical study, 52 students of Babol Midwifery College were participated in the study. 20 students were evaluated using TAM in November 2010, and 32 students were evaluated using the OSCE method in July 2011. Data were collected via a two-component questionnaire including demographic data and the test anxiety inventory (TAI). Results: All of midwifery students were women;the mean age of students, ages of father and mother’s were 23.1 ± 0.7, 52.3 ± 3.5 and 47.8 ± 4.9 years, respectively. Most of the students were single (61.5%). The mean education levels of father and mother’s were 11.6 ± 4.5 and 9.9 ± 4.0 years, respectively. The mean score of test anxiety in students was 42.51 ± 13.16. The most of participants did have moderate test anxiety (56.9%), two present not had any test anxiety, 37.3% had low test anxiety, and 3.9% had severe test anxiety. In sum, 98% had some degrees of test anxiety. There were the statistical differences in the mean score of text anxiety in OSCEs Compared with TAM in Undergraduate Midwifery Students (39.38 ± 13.81 vs. 47.35 ± 10.67, P = 0.033). Also, the mean severity of anxiety was different in two groups. The mean of moderate/severe test anxiety was more in TAM compared with OSCEs (52.57% vs. 49.56%, p = 0.000). The test anxiety had a positive correlation with father’s education, mother’s education (0.286, p = 0.042), father’s age, mother’s age, marital status, residency (0.292, p = 0.042). Also, there are negative correlations with student age, satisfaction, total Grade Point Average (GPA) (-0.387, p = 0.007), final score, type of assessment (-0.298, p = 0.033). There is a significant difference between the severity anxiety residency in total (p = 0.10) and OSCEs (p = 0.049) groups, mother’s education in total (p = 0.005) and OSCEs groups (0.012) and GPA (p = 0.028). Conclusion: OSCEs were superior to TAM in the reduction of test anxiety in midwifery students. The prevalence of test anxiety was in TAM than OSCEs method;therefore, using OSCEs is acknowledged as an effective assessment tool and is seen as the gold standard for evaluating clinical performance.
文摘The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a criterion of critical importance to software quality. Reusability is an important quality factor to testability. Its early measurement in object oriented software especially at design phase, allows a design to be reapplied to a new problem without much extra effort. This research paper proposes a research framework for quantification process and does an extensive review on reusability of object oriented software. A metrics based model “Reusability Quantification of Object Oriented Design” has been proposed by establishing the relationship among design properties and reusability and justifying the correlation with the help of statistical measures. Also, “Reusability Quantification Model” is empirically validated and contextual significance of the study shows the high correlation for model acceptance. This research paper facilitates to software developers and designer, the inclusion of reusability quantification model to access and quantify software reusability for quality product.
文摘为解决复合绝缘子污闪抑制与伞裙结构协同优化中电气性能与经济性难以兼顾的难题,本文提出一种基于人工污秽试验数据的污闪预测与多目标优化方法。首先,通过人工污秽试验获取50组污闪电压,构建融合Tent混沌映射与黄金正弦机制的减法平均优化器(golden sine subtraction average based optimizer,GSABO)以优化BP神经网络预测模型。其次,采用二代非支配排序遗传算法(non-dominated sorting genetic algorithm II,NSGA-Ⅱ)建立以污闪电压最大化和硅橡胶用量最小化为目标的优化模型,引入电压-成本比(voltage-cost ratio,UCR)选取Pareto前沿最优解。最后,利用有限元仿真及预测模型双重验证优化后的复合绝缘子的电场分布特性和污闪电压。研究结果表明:GSABO-BP预测模型污闪电压平均相对误差为2.198%(R2=0.9856),优化后目标绝缘子污闪电压提升9.23%,硅橡胶用量降低17.02%;沿面最大场强由2.31 MV/m降至1.92 MV/m,电场不均匀系数降低14.9%。本研究为复合绝缘子伞裙结构设计提供了理论与应用依据。
文摘机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模型,结合非支配排序遗传算法(Non-dominated Sorting Genetic Algorithm-Ⅱ,NSGA-Ⅱ)生成Pareto解集,最后采用优劣解距离(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)法决策最优参数组合。结果表明,优化后滑枕质量减少了29.3 kg,较优化前降低了4.7%,最大变形降低了5.8%,一阶固有频率保持稳定在553.3 Hz,表明该方法为机床零/部件多参数耦合优化提供了新的参考。
