目前的测试用例生成技术生成的测试用例集对程序中的定义使用对的覆盖率很低。为了提高测试用例集对程序中定义使用对的覆盖率,本文提出了一种基于数据流约简的测试用例生成策略。该策略首先利用静态分析工具Da Te C与多态定义使用对DU...目前的测试用例生成技术生成的测试用例集对程序中的定义使用对的覆盖率很低。为了提高测试用例集对程序中定义使用对的覆盖率,本文提出了一种基于数据流约简的测试用例生成策略。该策略首先利用静态分析工具Da Te C与多态定义使用对DUP对源码进行分析,构建出源码中全部定义使用对;然后,结合控制流图对上述定义使用对进行覆盖约简并根据覆盖约简后的定义使用对的路径谓词生成测试用例。实验结果表明,该方法可以提高测试用例集对程序中定义使用对的覆盖率,进而可以提高测试用例集的质量,更加彻底地对面向对象程序进行测试。展开更多
The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, e...The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, effective permeability and skin factor at the same time. Based on transient flow theory, the pressure drawdown equation of gas unsteady seepage can be deducted. One simulated case is used to illustrate the applicability of the proposed method. The result of analyzed case shows that the proposed method can provide accurate estimate of formation permeability and skin factor compared with the method of Homer curves.展开更多
The leakage research on supercritical carbon dioxide fluid in rolling piston expander was investigated experimentally.Using expander instead of throttle valve is an important way to improve the efficiency of carbon di...The leakage research on supercritical carbon dioxide fluid in rolling piston expander was investigated experimentally.Using expander instead of throttle valve is an important way to improve the efficiency of carbon dioxide refrigeration system.However,the supercritical fluid leakage in expander is serious and is the main factor affecting the expander's efficiency.This paper presented and compared four classic leakage models.The analysis indicated that laminar leakage model is suitable in leakage simulation of expander.A leakage test system,including the leakage test part which has two types of leakage specimens with different gaps ranging from 5 to 15 m,was established.The experimental results indicated that lubricant film played an important role.When the leakage clearance of cylindrical specimen was 5 m,the mass flow rate of leakage was about 0.88 g s-1.The data was 3.638 g s-1 with leakage clearance being 10 m and 7.11g s-1 with leakage clearance being 15 m.A modified leakage model was developed,whose average deviation was within 10% compared with the experimental data.At last,this paper simulated the leakage in rolling piston expander presented by Tian et al.(2010).The leakage between rolling piston and cylinder was the most serious part with the value up to 0.04 kg s-1.展开更多
文摘目前的测试用例生成技术生成的测试用例集对程序中的定义使用对的覆盖率很低。为了提高测试用例集对程序中定义使用对的覆盖率,本文提出了一种基于数据流约简的测试用例生成策略。该策略首先利用静态分析工具Da Te C与多态定义使用对DUP对源码进行分析,构建出源码中全部定义使用对;然后,结合控制流图对上述定义使用对进行覆盖约简并根据覆盖约简后的定义使用对的路径谓词生成测试用例。实验结果表明,该方法可以提高测试用例集对程序中定义使用对的覆盖率,进而可以提高测试用例集的质量,更加彻底地对面向对象程序进行测试。
文摘The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, effective permeability and skin factor at the same time. Based on transient flow theory, the pressure drawdown equation of gas unsteady seepage can be deducted. One simulated case is used to illustrate the applicability of the proposed method. The result of analyzed case shows that the proposed method can provide accurate estimate of formation permeability and skin factor compared with the method of Homer curves.
基金supported by the National Natural Science Foundation of China (Grant No. 50676064)
文摘The leakage research on supercritical carbon dioxide fluid in rolling piston expander was investigated experimentally.Using expander instead of throttle valve is an important way to improve the efficiency of carbon dioxide refrigeration system.However,the supercritical fluid leakage in expander is serious and is the main factor affecting the expander's efficiency.This paper presented and compared four classic leakage models.The analysis indicated that laminar leakage model is suitable in leakage simulation of expander.A leakage test system,including the leakage test part which has two types of leakage specimens with different gaps ranging from 5 to 15 m,was established.The experimental results indicated that lubricant film played an important role.When the leakage clearance of cylindrical specimen was 5 m,the mass flow rate of leakage was about 0.88 g s-1.The data was 3.638 g s-1 with leakage clearance being 10 m and 7.11g s-1 with leakage clearance being 15 m.A modified leakage model was developed,whose average deviation was within 10% compared with the experimental data.At last,this paper simulated the leakage in rolling piston expander presented by Tian et al.(2010).The leakage between rolling piston and cylinder was the most serious part with the value up to 0.04 kg s-1.
