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Mutation testing is a fault-based testing technique that can be used to measure the adequacy of a test set, but its application usually incurs a high cost due to the necessity of generating and executing a great number of mutants....
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Mutation testing is a fault-based testing technique that can be used to measure the adequacy of a test set, but its application usually incurs a high cost due to the necessity of generating and executing a great number of mutants. How to reduce the cost still remains a challenge for research. In this paper, we present a new mutant generation algorithm based on a basic path coverage that can help reduce mutants. ' The algorithm is characterized by implementing a basic path segments identification criterion for determining appropriate program points at which faults are inserted and a mutant generation priority criterion for selecting proper mutant operators to make a fault for insertion. We discuss the algorithm by analysing how the two criteria are realized based on analysing the control flow graph of the program and applying effective mutation operators on the appropriate statements in the relevant path segments. We also present an automated mutation testing tool that supports the proposed approach, and a small experiment to evaluate our tool by comparing it with a traditional mutation testing method on six programs. The result of the experiment suggests that the proposed method can significantly reduce the number of mutants and improve the efficiency of mutation testing.
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摘要 :
Mutation testing is a fault-based testing technique that can be used to measure the adequacy of a test set, but its application usually incurs a high cost due to the necessity of generating and executing a great number of mutants....
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Mutation testing is a fault-based testing technique that can be used to measure the adequacy of a test set, but its application usually incurs a high cost due to the necessity of generating and executing a great number of mutants. How to reduce the cost still remains a challenge for research. In this paper, we present a new mutant generation algorithm based on a basic path coverage that can help reduce mutants. ' The algorithm is characterized by implementing a basic path segments identification criterion for determining appropriate program points at which faults are inserted and a mutant generation priority criterion for selecting proper mutant operators to make a fault for insertion. We discuss the algorithm by analysing how the two criteria are realized based on analysing the control flow graph of the program and applying effective mutation operators on the appropriate statements in the relevant path segments. We also present an automated mutation testing tool that supports the proposed approach, and a small experiment to evaluate our tool by comparing it with a traditional mutation testing method on six programs. The result of the experiment suggests that the proposed method can significantly reduce the number of mutants and improve the efficiency of mutation testing.
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摘要 :
As oil and gas exploration and production extends to deeper buried reservoirs, challenges such as lower porosities and Ultra High Temperature have been encountered. Several reservoirs in the Asian region, the North Malay basins in...
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As oil and gas exploration and production extends to deeper buried reservoirs, challenges such as lower porosities and Ultra High Temperature have been encountered. Several reservoirs in the Asian region, the North Malay basins in the joint development area between Thailand and Malaysia, and the Baiyun Sag and Qiong Dongnan basin in offshore China are considered to have the highest known temperature gradients due to their geological depositional system and hydrocarbon charging mechanism. More than fifty percent of wells drilled in these areas have temperature close to/or higher than 170 degC, and some reach above 200 degC. In number a of projects in these areas, the logging requires tools that can withstand up to 230 degC.Traditional, wireline Formation Testers (FT) with fixed rate and volume pre-test and old sampling technique using a dumping chamber (i.e. without pumping capability) had been the standard formation tester when temperatures reached 400degF (204 degC) and higher. The tools were not flasked and therefore, the temperature transient affected the quality and accuracy of pressure data～(1,2). Also, in such harsh environment, it is very difficult and time consuming to go back to a good mobility station for sampling after pressure measurement, due to reservoir heterogeneity and depth error.This paper discusses a project for a new slim hole ultrahigh temperature Wireline Formation Tester designed to obtain both pressure profiles and perform downhole Pressure Volume Temperature (PVT) *Trademark of Schlumberger fluid sampling with pump-out capability and downhole fluid sensors such as viscosity, density and resistivity in extreme HT environments. In addition, this slim hole ultrahigh temperature tool dimension has more clearance between the tool and formation, and therefore, less chance of having this tool get stuck during slim hole logging.The tool was first deployed in the North Malay Basin and since early 2018, new well head platform with five development wells were logged where a total of 76 pre-tests, four pump-out and ten fluid sampling stations were conducted. The main objectives for this FT tool were to obtain formation pressure, identify reservoir fluid and quantitative CO2 measurements zone by zone. The results will be discussed operationally and technically, in terms of data quality and accuracy and compared with on-site surface analysis. In addition, this tool improves significantly operationally compared to the previous tools and with some operators having mixed perceptions on running Wireline FT tool with bigger ODs, especially drilling departments, having this new slim hole with its smaller OD increases their confidence level in running it.For Deepwater Offshore China, an operator has been facing challenges to explore a brand-new block such as pore pressure distributions profile, reservoir quality, and extended logging period. The main objectives for the extreme FT are to obtain the formation pressure for drilling purpose, to understand reservoir potential to optimize the perforation interval for Drill Stem Test, and to narrow logging operation time window due to seasonal weather. This new ultra-high slim hole was therefore proposed to log in this challenging environment. This field example shows a significantly improved pre-test and sampling capability in the lower mobility ranges, which some previous generations of formation testers had struggled with in the past, in one run and without sacrificing testing efficiency The effective time for valid pretest can be achieved even in the range of mobility 0.01 mD/cp, high pressure of ＞ 11000 psi, and high temperature of ＞ 180 degC.This paper discusses pre-job planning and actual job execution results in both locations. The challenges of logging and lesson learned are addressed. This is the first attempt in evaluating reservoirs in the deeper and HT sections to properly understand reservoir fluids.
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摘要 :
As oil and gas exploration and production extends to deeper buried reservoirs, challenges such as lower porosities and Ultra High Temperature have been encountered. Several reservoirs in the Asian region, the North Malay basins in...
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As oil and gas exploration and production extends to deeper buried reservoirs, challenges such as lower porosities and Ultra High Temperature have been encountered. Several reservoirs in the Asian region, the North Malay basins in the joint development area between Thailand and Malaysia, and the Baiyun Sag and Qiong Dongnan basin in offshore China are considered to have the highest known temperature gradients due to their geological depositional system and hydrocarbon charging mechanism. More than fifty percent of wells drilled in these areas have temperature close to/or higher than 170 degC, and some reach above 200 degC. In number a of projects in these areas, the logging requires tools that can withstand up to 230 degC.Traditional, wireline Formation Testers (FT) with fixed rate and volume pre-test and old sampling technique using a dumping chamber (i.e. without pumping capability) had been the standard formation tester when temperatures reached 400degF (204 degC) and higher. The tools were not flasked and therefore, the temperature transient affected the quality and accuracy of pressure data～(1,2). Also, in such harsh environment, it is very difficult and time consuming to go back to a good mobility station for sampling after pressure measurement, due to reservoir heterogeneity and depth error.This paper discusses a project for a new slim hole ultrahigh temperature Wireline Formation Tester designed to obtain both pressure profiles and perform downhole Pressure Volume Temperature (PVT) *Trademark of Schlumberger fluid sampling with pump-out capability and downhole fluid sensors such as viscosity, density and resistivity in extreme HT environments. In addition, this slim hole ultrahigh temperature tool dimension has more clearance between the tool and formation, and therefore, less chance of having this tool get stuck during slim hole logging.The tool was first deployed in the North Malay Basin and since early 2018, new well head platform with five development wells were logged where a total of 76 pre-tests, four pump-out and ten fluid sampling stations were conducted. The main objectives for this FT tool were to obtain formation pressure, identify reservoir fluid and quantitative CO2 measurements zone by zone. The results will be discussed operationally and technically, in terms of data quality and accuracy and compared with on-site surface analysis. In addition, this tool improves significantly operationally compared to the previous tools and with some operators having mixed perceptions on running Wireline FT tool with bigger ODs, especially drilling departments, having this new slim hole with its smaller OD increases their confidence level in running it.For Deepwater Offshore China, an operator has been facing challenges to explore a brand-new block such as pore pressure distributions profile, reservoir quality, and extended logging period. The main objectives for the extreme FT are to obtain the formation pressure for drilling purpose, to understand reservoir potential to optimize the perforation interval for Drill Stem Test, and to narrow logging operation time window due to seasonal weather. This new ultra-high slim hole was therefore proposed to log in this challenging environment. This field example shows a significantly improved pre-test and sampling capability in the lower mobility ranges, which some previous generations of formation testers had struggled with in the past, in one run and without sacrificing testing efficiency The effective time for valid pretest can be achieved even in the range of mobility 0.01 mD/cp, high pressure of ＞ 11000 psi, and high temperature of ＞ 180 degC.This paper discusses pre-job planning and actual job execution results in both locations. The challenges of logging and lesson learned are addressed. This is the first attempt in evaluating reservoirs in the deeper and HT sections to properly understand reservoir fluids.
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In this paper, we solve the consistency checking problems of concurrent and real-time system designs modelled by time Petri nets for the scenario-based specifications expressed by message sequence charts (MSCs). The algorithm we p...
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In this paper, we solve the consistency checking problems of concurrent and real-time system designs modelled by time Petri nets for the scenario-based specifications expressed by message sequence charts (MSCs). The algorithm we present can be used to check if a time Petri net satisfies a specification expressed by a given MSC which requires that if a scenario described by the MSC occurs during the run of the time Petri net, the timing constraints enforced to the MSC must be satisfied.
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A shoe-mounted indoor positioning system is designed based on the low-cost MEMS (Micro-Electro-Mechanical System) inertial measurement unit (TMU). To solve the problem of the high noise and drift of the MEMS inertial sensor, the m...
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A shoe-mounted indoor positioning system is designed based on the low-cost MEMS (Micro-Electro-Mechanical System) inertial measurement unit (TMU). To solve the problem of the high noise and drift of the MEMS inertial sensor, the method of the coarse calibration for MIMU is studied. Aiming at solving the shortcomings of the traditional zero velocity interval detection algorithm with single threshold, an alternative algorithm for the zero velocity interval detection based on multiple gaits is designed, which judges the motion state before detection. Then, the Kalman filter algorithm based on the zero velocity update (ZUPT) and zero angular rate update (ZARU) is designed to estimate and compensate the cumulative error of the sensors during walking. Finally, a field test based on a low-cost MEMS IMU is carried out with four different gaits, slow walking, up and down staircase, striding forward and long-distance walking with variable speed. The results show that the positioning error of the proposed method is only 3% of the walking distance.
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摘要 :
A shoe-mounted indoor positioning system is designed based on the low-cost MEMS (Micro-Electro-Mechanical System) inertial measurement unit (TMU). To solve the problem of the high noise and drift of the MEMS inertial sensor, the m...
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A shoe-mounted indoor positioning system is designed based on the low-cost MEMS (Micro-Electro-Mechanical System) inertial measurement unit (TMU). To solve the problem of the high noise and drift of the MEMS inertial sensor, the method of the coarse calibration for MIMU is studied. Aiming at solving the shortcomings of the traditional zero velocity interval detection algorithm with single threshold, an alternative algorithm for the zero velocity interval detection based on multiple gaits is designed, which judges the motion state before detection. Then, the Kalman filter algorithm based on the zero velocity update (ZUPT) and zero angular rate update (ZARU) is designed to estimate and compensate the cumulative error of the sensors during walking. Finally, a field test based on a low-cost MEMS IMU is carried out with four different gaits, slow walking, up and down staircase, striding forward and long-distance walking with variable speed. The results show that the positioning error of the proposed method is only 3% of the walking distance.
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The optimization of a large number of decision variables, so called large scale global optimization (LSGO) remains challenging for existing heuristics. Inspired by the concept of global best (gbest) guided strategy, this paper pro...
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The optimization of a large number of decision variables, so called large scale global optimization (LSGO) remains challenging for existing heuristics. Inspired by the concept of global best (gbest) guided strategy, this paper proposes a gbest-guided covariance matrix adaptation evolution strategy (GCMA-ES) where the gbest information is utilized in the search equation to guide the exploitation process. The GCMA-ES can take advantages from both the CMA-ES and the gbest-guided strategy. Its performance is demonstrated on the CEC 2010 LSGO benchmarks.
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摘要 :
The optimization of a large number of decision variables, so called large scale global optimization (LSGO) remains challenging for existing heuristics. Inspired by the concept of global best (gbest) guided strategy, this paper pro...
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The optimization of a large number of decision variables, so called large scale global optimization (LSGO) remains challenging for existing heuristics. Inspired by the concept of global best (gbest) guided strategy, this paper proposes a gbest-guided covariance matrix adaptation evolution strategy (GCMA-ES) where the gbest information is utilized in the search equation to guide the exploitation process. The GCMA-ES can take advantages from both the CMA-ES and the gbest-guided strategy. Its performance is demonstrated on the CEC 2010 LSGO benchmarks.
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An effective way to decrease the dephosphorization burden in the current vanadium extraction-steelmaking process is slagging with CaO in vanadium extraction step. The phase composition of vanadium slag with different basicity and ...
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An effective way to decrease the dephosphorization burden in the current vanadium extraction-steelmaking process is slagging with CaO in vanadium extraction step. The phase composition of vanadium slag with different basicity and the regularities distribution of elements have been investigated by X-ray diffraction analysis and scanning electron microscopy combining with energy disperse X-ray spectrometry, respectively. The results indicate that V mainly concentrates in the spinel phases; Ca and P are rich in the silicate phases. Fe_2SiO_4 transform to CaFeSiO_4, while the basicity of vanadium slag is 1.3. With further increase of basicity, 2CaO·SiO_2 could form in the silicate phases. Moreover, the phosphorus-containing phase will transform from Ca_3(PO_4)_2 to Ca_3(PO_4)_2-nCa_2SiO_4. With the increase of P_2O_5 content, the crystallization rate of spinels decrease obviously. Furthermore, the peak temperature for crystallization of spinels decrease 5 K with the P_2O_5 content increasing 1 wt%.
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