This is a continuation of the article“Ground Monitoring of Microseismic Based on Low Signal-to-Noise Ratio”,and a further summary and reflection after investigating the current situation of microseismic monitoring.I...This is a continuation of the article“Ground Monitoring of Microseismic Based on Low Signal-to-Noise Ratio”,and a further summary and reflection after investigating the current situation of microseismic monitoring.It is difficult to provide necessary and sufficient conditions to test the reliability of microseismic monitoring.Often,a few hundred meters away,the microseismic signal emitted by a hypocenter is submerged in noise,and the traditional location is invalid;Inversion for microseismic released energy distribution using data migration and stacking is in principle not unique.However,based on microseismic monitoring characteristics,forward and reverse simulations and numerous experiments,many necessary conditions can be proposed to ensure reliable monitoring with high probability.VS(Vector Scanning)ground monitoring for microseismic proposes eight necessary conditions for testing the reliability,so that VS finds the fracturing-induced effective communication seam with the characteristics of shear zones under the control of tectonic stress fields,in line with the laws of seismic and geological observations,as well as the features related to some special production data.VS uses data migration and stacking suitable for low signal-to-noise ratio and shear mechanism,and the joint inversion for correction of both traditional relocations and velocity model,can greatly improve monitoring distance and quality,complete microseismic measurement methods,and broaden applicable fields,such as:(1)VS can be a cost-effective,ground-based,routine monitoring method;(2)The BPM(Borehole Proximity Monitoring)is high cost but close to the hypocenters;It can be the best method for scientific research,but its seismic network should be improved,and the joint inversion and data stacking could be used to improve the monitoring distance and quality;(3)The early warning of mine safety can change the current monitoring of strong microseismic(or accidents have been happened)to the real microseismic level;and(4)The seismic precursor monitoring of large earthquakes can be expanded from small earthquakes to microseismic.These will establish a solid foundation and complete seismic measurements for microseismology.展开更多
In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses...In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high prestress.It is essential to study the support components performance under dynamic-static coupling conditions.Based on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so on.The bolt and cable mechanical tests are conducted by MAC system under different prestress levels.The results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly reduced.In the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress condition.In the prestress range of 150–300 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress condition.The MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system.展开更多
Investigations into rail corrugation within metro systems have traditionally focused on specific mechanisms,thereby limiting the generalizability of proposed theories.Understanding the commonalities in rail corrugatio...Investigations into rail corrugation within metro systems have traditionally focused on specific mechanisms,thereby limiting the generalizability of proposed theories.Understanding the commonalities in rail corrugation across diverse metro lines remains pivotal for elucidating its underlying mechanisms.The present study conducted extensive field surveys and tracking tests across 14 Chinese metro lines.By employing t-distributed stochastic neighbor embedding(t-SNE)for dimensional reduction and employing the unsupervised clustering algorithm DBSCAN,the research redefines the classification of metro rail corrugation based on characteristic information.The analysis encompassed spatial distribution and temporal evolution of this phenomenon.Findings revealed that floating slab tracks exhibited the highest proportion of rail corrugation at 47%.Notably,ordinary monolithic bed tracks employing damping fasteners were more prone to inducing rail corrugation.Corrugation primarily manifested in curve sections with radii between 300 and 500 m,featuring ordinary monolithic bed track and steel-spring floating slab track structures,with wavelengths typically between 30 and 120 mm.Stick–slip vibrations of the wheel–rail system maybe led to short-wavelength corrugations(40–60 mm),while longer wavelengths(200–300 mm)exhibited distinct fatigue damage characteristics,mainly observed in steel-spring floating slab tracks and small-radius curve sections of ordinary monolithic bed tracks and ladder sleeper tracks.A classification system comprising 57 correlated features categorized metro rail corrugation into four distinct types.These research outcomes serve as critical benchmarks for validating various theories pertaining to rail corrugation formation.展开更多
The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational i...The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational instability may occur for high vertical resolution versions if the stratification parameter C0 taken as a constant. In this paper, the possible cause leading to the instability is discussed and an improved scheme presented where C0 is generalized to be a function of both height and latitudes. Hence the reference atmosphere gets closer to the real atmosphere and the temperature deviation field to be expanded becomes smoother everywhere. Test by real case forecasts shows good computational stability of the new scheme and better prediction performance than-usual schemes of spectral model.展开更多
Software testing is a critical phase due to misconceptions about ambiguities in the requirements during specification,which affect the testing process.Therefore,it is difficult to identify all faults in software.As re...Software testing is a critical phase due to misconceptions about ambiguities in the requirements during specification,which affect the testing process.Therefore,it is difficult to identify all faults in software.As requirement changes continuously,it increases the irrelevancy and redundancy during testing.Due to these challenges;fault detection capability decreases and there arises a need to improve the testing process,which is based on changes in requirements specification.In this research,we have developed a model to resolve testing challenges through requirement prioritization and prediction in an agile-based environment.The research objective is to identify the most relevant and meaningful requirements through semantic analysis for correct change analysis.Then compute the similarity of requirements through case-based reasoning,which predicted the requirements for reuse and restricted to error-based requirements.Afterward,the apriori algorithm mapped out requirement frequency to select relevant test cases based on frequently reused or not reused test cases to increase the fault detection rate.Furthermore,the proposed model was evaluated by conducting experiments.The results showed that requirement redundancy and irrelevancy improved due to semantic analysis,which correctly predicted the requirements,increasing the fault detection rate and resulting in high user satisfaction.The predicted requirements are mapped into test cases,increasing the fault detection rate after changes to achieve higher user satisfaction.Therefore,the model improves the redundancy and irrelevancy of requirements by more than 90%compared to other clustering methods and the analytical hierarchical process,achieving an 80%fault detection rate at an earlier stage.Hence,it provides guidelines for practitioners and researchers in the modern era.In the future,we will provide the working prototype of this model for proof of concept.展开更多
Objective:To develop and test the reliability and validity of a new instrument,the Nurse eNurse Collaboration Behavior Scale(NNCBS).Background:The importance of cooperation among nurses is widely acknowledged,but is a...Objective:To develop and test the reliability and validity of a new instrument,the Nurse eNurse Collaboration Behavior Scale(NNCBS).Background:The importance of cooperation among nurses is widely acknowledged,but is a lack of scientific studies regarding the behaviorial interactions associated with nurse enurse relationships throughout the process of patient-centered care.Therefore,there is a great need to develop a reliable scale to measure nurseenurse collaboration behavior,which is what we have generated in this study.Methods:The 46-item Nursee-Nurse Collaboration Scale was developed using a process of item design,refinement,and testing for both reliability and validity.In 2014,the 202 nurses from the International Department of Services participated in this pilot study.Cronbach's a coefficients and testeretest reliability coefficients were calculated in order to evaluate this new scale's internal consistency and stability.Exploratory factor analysis was calculated using a principal factor method with promax rotation to evaluate the scale's validity.Results:Exploratory factor analysis yielded four factors and 23 items.The overall Cronbach's a coefficient of the scale was 0.929.The item-total correlation values were overall high,ranging from 0.427 to 0.751.For the entire scale,the r values of the testeretest reliability correlations were 0.764.Conclusion:The NNCB Scale developed in this study demonstrates acceptable reliability and validity for measuring the level of NNCB.Its implementration on a broader scale would at the very least guide and promote collaborative relationships between nurses involved in patient care.It should be noted that the scale requires further psychometric testing using a larger sample size of nurses who also represent a wider diversity of backgrounds,as well as researchers who are encouraged to improve the instrument.展开更多
Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communica...Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communication techniques, which can accurately control the testing machine and measure the fracture toughness in real-time. Three-point bending specimens were used in the measurement. The software operates stably and reliably, expanding the function of WDW series testing machine.展开更多
The outbreak of the SARS-CoV-2 virus in early 2020,known as COVID-19,spread to more than 200 countries and negatively affected the global economic output.Financial activities were primarily depressed,and investors wer...The outbreak of the SARS-CoV-2 virus in early 2020,known as COVID-19,spread to more than 200 countries and negatively affected the global economic output.Financial activities were primarily depressed,and investors were reluctant to start new financial investments while ongoing projects further declined due to the global lockdown to curb the disease.This study analyzes the money supply reaction to the COVID-19 pandemic using a cross-sectional panel of 115 countries.The study used robust least square regression and innovation accounting techniques to get sound parameter estimates.The results show that COVID-19 infected cases are the main contributing factor that obstructs financial activities and decrease money supply.In contrast,an increasing number of recovered cases and COVID-19 testing capabilities gave investors confidence to increase stock trade across countries.The overall forecast trend shows that COVID-19 infected cases and recovered cases followed the U-shaped trend,while COVID-19 critical cases and reported deaths showed a decreasing trend.Finally,the money supply and testing capacity show a positive trend over a period.The study concludes that financial development can be expanded by increasing the testing capacity and functional labs to identify suspected coronavirus cases globally.展开更多
This paper investigates the development of a spoken English test.The nature of speaking test and its design principles are first reviewed.Then the procedure of the test development is elaborated in detail,namely,desig...This paper investigates the development of a spoken English test.The nature of speaking test and its design principles are first reviewed.Then the procedure of the test development is elaborated in detail,namely,design stage,construction stage and try out stage.The challenges facing the development of spoken test are finally discussed.展开更多
Aim:To elucidate the distribution and regulation of Neuropeptide Y(NPY)gene expression in testes under physiologi- cal and pathophysiological conditions,such as testicular development,fasting and experimental cryptorc...Aim:To elucidate the distribution and regulation of Neuropeptide Y(NPY)gene expression in testes under physiologi- cal and pathophysiological conditions,such as testicular development,fasting and experimental cryptorchidism. Methods:In the first experiment,C57BL/6J male mice at the ages of 3 days as well as 2,3,5 and 8 weeks were used. In the second and third experiments,adult C57BL/6J male mice were subjected to fasting for 48 h and experimental cryptorchidism for 72 h.The NPY transcripts were detected by isotopic in situ hybridization histochemistry.Results: The NPY transcripts were exclusively expressed in the interstitial cells regardless of the age groups and experimental conditions.The NPY mRNA levels were found to increase significantly with age(from the neonatal to prepubertal period [P<0.01] and from the prepubetal to postpubertal period [P<0.01]).Food deprivation for 48 h resulted in a significant increase in the NPY mRNA levels in the arcuate nucleus of the hypothalamus(P<0.01),but not in the testes.Experimental cryptorchidism for 72 h failed to regulate the NPY gene expression in the testes.Conclusion: NPY gene expression is distributed in Leydig cells and increases in line with testicular development.The regulation of testicular NPY is different from that of hypothalamic NPY.(Asian J Androl 2006 Jul;8:443-449)展开更多
China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualitie...China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.展开更多
With the development of economy and the improvement of people's living standards, the use of cars in families has become more and more common, the reliability of the quality of the car in the process of car use is...With the development of economy and the improvement of people's living standards, the use of cars in families has become more and more common, the reliability of the quality of the car in the process of car use is very important. Therefore, in the process of automobile development, automobile enterprises have not paid attention to vehicle reliability tests, including vehicle tests on real roads, virtual roads, environmental reliability and other aspects, so as to ensure the reliability of the vehicle in all aspects, and thus guarantee the driving safety of passengers.展开更多
At present, the problem of environmental loss is becoming more and more serious. In order to realize the sustainable development of the environment, it is necessary to increase the research of environmental monitoring...At present, the problem of environmental loss is becoming more and more serious. In order to realize the sustainable development of the environment, it is necessary to increase the research of environmental monitoring technology. If the environment is polluted, it will bring a series of chain reactions. If the specific pollution problem cannot be effectively controlled in a timely manner, it will seriously damage the entire ecosystem. At the same time, it will be irreversible. The environment on which people depend for their survival will also be adversely affected. If it continues to develop for a long time, it will be very disadvantageous to the development of the national economy as a whole. Based on this, this article focuses on the in-depth research and analysis of environmental testing technology and ecological sustainable development.展开更多
Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft su...Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed , which possesses such advantages as simple structure , reliable cutoff , and high energy performance.Taking some pumping stations as the case studies , in the light of the specified operation conditions , the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended.The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted.The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station.Finally , the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency , more reliable and stable.展开更多
With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals...With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals of deep mining device need to be developed.Therefore,considering the use of dynamic seals in unique deep mining environments,an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed.The results show that the experimental device can operate stably under a pressure of up to150 MPa and a rotating speed of 76 r/min,and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa.During the operation of the ultra-high-pressure rotating combined dynamic seal,the sealing ring does not show obvious damage,which vouches for its sealing performance.No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0-150 MPa.Therefore,the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth.The research and development of this device can aid future deep energy exploration and exploitation.展开更多
The study investigated the relationship among remittances,financial development and economic growth in a panel of 20 sub-Saharan African countries over the period of 2000 and 2015.The study used both Pooled Mean Group...The study investigated the relationship among remittances,financial development and economic growth in a panel of 20 sub-Saharan African countries over the period of 2000 and 2015.The study used both Pooled Mean Group and Mean Group/ARDL estimations with panel unit root and cointegration tests.After establishing cointegration,remittances and financial development were found to have positive effects on economic growth both in the short and the long run.The interactive term showed that financial development acted as a substitute in the remittances-growth relationship.Finally,unidirectional causal relationships were found to exist from GDP to remittances and from financial development to GDP.However,no causality existed between remittances and financial development in the SSA countries.展开更多
This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the a...This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the augmented mean group procedure,which accounts for country-specific heterogeneity and crosssectional dependence,and the Granger non-causality test to test for causality in the presence of cross-sectional dependence.The results show that(1)The impact of financial sector development on domestic investment depends on the measure of financial sector development utilised;(2)Domestic credit to the private sector has a positive but insignificant impact on domestic investment in ECOWAS,whereas banking intermediation efficiency(i.e.,ability of the banks to transform deposits into credit)and broad money supply negatively and significant influence domestic investment;(3)Cross-country differences exist in the impact of financial sector development on domestic investment in the selected ECOWAS countries;and(4)Domestic credit to the private sector Granger causes domestic investment in ECOWAS.The study recommends careful consideration in the measure of financial development that is utilised as a policy instrument to foster domestic investment.We also highlight the importance of employing country-specific domestic investment policies to avoid blanket policy measures.Domestic credit to the private sector should be given priority when forecasting domestic investment into the future.展开更多
Urban-rural interaction and conjunctionaldevelopment is the effective way of harmonizingurban-rural relationship and promoting urban-ruraldevelopment. However, there are differences in thelevel of urban-rural interact...Urban-rural interaction and conjunctionaldevelopment is the effective way of harmonizingurban-rural relationship and promoting urban-ruraldevelopment. However, there are differences in thelevel of urban-rural interaction and conjunctionaldevelopment of China. How to measure and reflectthe difference properly is a decision-makingfoundation for optimizing urban-rural developmentof different regions. The paper employs multiplemethods to evaluate and order the urban-ruralinteraction and conjunctional development of 31provinces (municipalities) in China. Kendall’s Wconsistency coefficient is employed to give a consistenttest for the evaluation result series, and the resultsof multiple methods are aggregated as the finalevaluation value. The results reflect the level ofregional urban-rural interaction and conjunctionaldevelopment in China.展开更多
文摘This is a continuation of the article“Ground Monitoring of Microseismic Based on Low Signal-to-Noise Ratio”,and a further summary and reflection after investigating the current situation of microseismic monitoring.It is difficult to provide necessary and sufficient conditions to test the reliability of microseismic monitoring.Often,a few hundred meters away,the microseismic signal emitted by a hypocenter is submerged in noise,and the traditional location is invalid;Inversion for microseismic released energy distribution using data migration and stacking is in principle not unique.However,based on microseismic monitoring characteristics,forward and reverse simulations and numerous experiments,many necessary conditions can be proposed to ensure reliable monitoring with high probability.VS(Vector Scanning)ground monitoring for microseismic proposes eight necessary conditions for testing the reliability,so that VS finds the fracturing-induced effective communication seam with the characteristics of shear zones under the control of tectonic stress fields,in line with the laws of seismic and geological observations,as well as the features related to some special production data.VS uses data migration and stacking suitable for low signal-to-noise ratio and shear mechanism,and the joint inversion for correction of both traditional relocations and velocity model,can greatly improve monitoring distance and quality,complete microseismic measurement methods,and broaden applicable fields,such as:(1)VS can be a cost-effective,ground-based,routine monitoring method;(2)The BPM(Borehole Proximity Monitoring)is high cost but close to the hypocenters;It can be the best method for scientific research,but its seismic network should be improved,and the joint inversion and data stacking could be used to improve the monitoring distance and quality;(3)The early warning of mine safety can change the current monitoring of strong microseismic(or accidents have been happened)to the real microseismic level;and(4)The seismic precursor monitoring of large earthquakes can be expanded from small earthquakes to microseismic.These will establish a solid foundation and complete seismic measurements for microseismology.
基金supported by the National Natural Science Foundation of China(Nos.51927807,52074164,42277174,42077267 and 42177130)the Natural Science Foundation of Shandong Province,China(No.ZR2020JQ23)China University of Mining and Technology(Beijing)Top Innovative Talent Cultivation Fund for Doctoral Students(No.BBJ2023048)。
文摘In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high prestress.It is essential to study the support components performance under dynamic-static coupling conditions.Based on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so on.The bolt and cable mechanical tests are conducted by MAC system under different prestress levels.The results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly reduced.In the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress condition.In the prestress range of 150–300 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress condition.The MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system.
基金support extended by the Joint Funds of Beijing Municipal Natural Science Foundation and Fengtai Rail Transit Frontier Research(Grant No.L211006)the Fundamental Research Funds for the Central Universities(Science and technology leading talent team project,Grant No.2022JBXT010)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2023YJS052)the National Natural Science Foundation of China(Grant No.52308426)。
文摘Investigations into rail corrugation within metro systems have traditionally focused on specific mechanisms,thereby limiting the generalizability of proposed theories.Understanding the commonalities in rail corrugation across diverse metro lines remains pivotal for elucidating its underlying mechanisms.The present study conducted extensive field surveys and tracking tests across 14 Chinese metro lines.By employing t-distributed stochastic neighbor embedding(t-SNE)for dimensional reduction and employing the unsupervised clustering algorithm DBSCAN,the research redefines the classification of metro rail corrugation based on characteristic information.The analysis encompassed spatial distribution and temporal evolution of this phenomenon.Findings revealed that floating slab tracks exhibited the highest proportion of rail corrugation at 47%.Notably,ordinary monolithic bed tracks employing damping fasteners were more prone to inducing rail corrugation.Corrugation primarily manifested in curve sections with radii between 300 and 500 m,featuring ordinary monolithic bed track and steel-spring floating slab track structures,with wavelengths typically between 30 and 120 mm.Stick–slip vibrations of the wheel–rail system maybe led to short-wavelength corrugations(40–60 mm),while longer wavelengths(200–300 mm)exhibited distinct fatigue damage characteristics,mainly observed in steel-spring floating slab tracks and small-radius curve sections of ordinary monolithic bed tracks and ladder sleeper tracks.A classification system comprising 57 correlated features categorized metro rail corrugation into four distinct types.These research outcomes serve as critical benchmarks for validating various theories pertaining to rail corrugation formation.
基金This work has been carried out under the support of the Medium-range Numerical Weather Forecast research project
文摘The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational instability may occur for high vertical resolution versions if the stratification parameter C0 taken as a constant. In this paper, the possible cause leading to the instability is discussed and an improved scheme presented where C0 is generalized to be a function of both height and latitudes. Hence the reference atmosphere gets closer to the real atmosphere and the temperature deviation field to be expanded becomes smoother everywhere. Test by real case forecasts shows good computational stability of the new scheme and better prediction performance than-usual schemes of spectral model.
文摘Software testing is a critical phase due to misconceptions about ambiguities in the requirements during specification,which affect the testing process.Therefore,it is difficult to identify all faults in software.As requirement changes continuously,it increases the irrelevancy and redundancy during testing.Due to these challenges;fault detection capability decreases and there arises a need to improve the testing process,which is based on changes in requirements specification.In this research,we have developed a model to resolve testing challenges through requirement prioritization and prediction in an agile-based environment.The research objective is to identify the most relevant and meaningful requirements through semantic analysis for correct change analysis.Then compute the similarity of requirements through case-based reasoning,which predicted the requirements for reuse and restricted to error-based requirements.Afterward,the apriori algorithm mapped out requirement frequency to select relevant test cases based on frequently reused or not reused test cases to increase the fault detection rate.Furthermore,the proposed model was evaluated by conducting experiments.The results showed that requirement redundancy and irrelevancy improved due to semantic analysis,which correctly predicted the requirements,increasing the fault detection rate and resulting in high user satisfaction.The predicted requirements are mapped into test cases,increasing the fault detection rate after changes to achieve higher user satisfaction.Therefore,the model improves the redundancy and irrelevancy of requirements by more than 90%compared to other clustering methods and the analytical hierarchical process,achieving an 80%fault detection rate at an earlier stage.Hence,it provides guidelines for practitioners and researchers in the modern era.In the future,we will provide the working prototype of this model for proof of concept.
文摘Objective:To develop and test the reliability and validity of a new instrument,the Nurse eNurse Collaboration Behavior Scale(NNCBS).Background:The importance of cooperation among nurses is widely acknowledged,but is a lack of scientific studies regarding the behaviorial interactions associated with nurse enurse relationships throughout the process of patient-centered care.Therefore,there is a great need to develop a reliable scale to measure nurseenurse collaboration behavior,which is what we have generated in this study.Methods:The 46-item Nursee-Nurse Collaboration Scale was developed using a process of item design,refinement,and testing for both reliability and validity.In 2014,the 202 nurses from the International Department of Services participated in this pilot study.Cronbach's a coefficients and testeretest reliability coefficients were calculated in order to evaluate this new scale's internal consistency and stability.Exploratory factor analysis was calculated using a principal factor method with promax rotation to evaluate the scale's validity.Results:Exploratory factor analysis yielded four factors and 23 items.The overall Cronbach's a coefficient of the scale was 0.929.The item-total correlation values were overall high,ranging from 0.427 to 0.751.For the entire scale,the r values of the testeretest reliability correlations were 0.764.Conclusion:The NNCB Scale developed in this study demonstrates acceptable reliability and validity for measuring the level of NNCB.Its implementration on a broader scale would at the very least guide and promote collaborative relationships between nurses involved in patient care.It should be noted that the scale requires further psychometric testing using a larger sample size of nurses who also represent a wider diversity of backgrounds,as well as researchers who are encouraged to improve the instrument.
文摘Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communication techniques, which can accurately control the testing machine and measure the fracture toughness in real-time. Three-point bending specimens were used in the measurement. The software operates stably and reliably, expanding the function of WDW series testing machine.
基金Researchers Supporting Project number(RSP-2020/87),King Saud University,Riyadh,Saudi Arabia.
文摘The outbreak of the SARS-CoV-2 virus in early 2020,known as COVID-19,spread to more than 200 countries and negatively affected the global economic output.Financial activities were primarily depressed,and investors were reluctant to start new financial investments while ongoing projects further declined due to the global lockdown to curb the disease.This study analyzes the money supply reaction to the COVID-19 pandemic using a cross-sectional panel of 115 countries.The study used robust least square regression and innovation accounting techniques to get sound parameter estimates.The results show that COVID-19 infected cases are the main contributing factor that obstructs financial activities and decrease money supply.In contrast,an increasing number of recovered cases and COVID-19 testing capabilities gave investors confidence to increase stock trade across countries.The overall forecast trend shows that COVID-19 infected cases and recovered cases followed the U-shaped trend,while COVID-19 critical cases and reported deaths showed a decreasing trend.Finally,the money supply and testing capacity show a positive trend over a period.The study concludes that financial development can be expanded by increasing the testing capacity and functional labs to identify suspected coronavirus cases globally.
文摘This paper investigates the development of a spoken English test.The nature of speaking test and its design principles are first reviewed.Then the procedure of the test development is elaborated in detail,namely,design stage,construction stage and try out stage.The challenges facing the development of spoken test are finally discussed.
文摘Aim:To elucidate the distribution and regulation of Neuropeptide Y(NPY)gene expression in testes under physiologi- cal and pathophysiological conditions,such as testicular development,fasting and experimental cryptorchidism. Methods:In the first experiment,C57BL/6J male mice at the ages of 3 days as well as 2,3,5 and 8 weeks were used. In the second and third experiments,adult C57BL/6J male mice were subjected to fasting for 48 h and experimental cryptorchidism for 72 h.The NPY transcripts were detected by isotopic in situ hybridization histochemistry.Results: The NPY transcripts were exclusively expressed in the interstitial cells regardless of the age groups and experimental conditions.The NPY mRNA levels were found to increase significantly with age(from the neonatal to prepubertal period [P<0.01] and from the prepubetal to postpubertal period [P<0.01]).Food deprivation for 48 h resulted in a significant increase in the NPY mRNA levels in the arcuate nucleus of the hypothalamus(P<0.01),but not in the testes.Experimental cryptorchidism for 72 h failed to regulate the NPY gene expression in the testes.Conclusion: NPY gene expression is distributed in Leydig cells and increases in line with testicular development.The regulation of testicular NPY is different from that of hypothalamic NPY.(Asian J Androl 2006 Jul;8:443-449)
文摘China is the biggest country of rice production and consumption in the world;more than 50% of the population feeds chiefly on rice. The quality of rice and its role as a staplefood carry much weight. The rice qualities are those aspects concerning processing, appearance,cooking, nutrition and safety of the product. The study, formulation and implementation of standardson rice qualities and testing bear heavily on the improving of rice qualities, human health,substitution of rice varieties, promoting quality rice production and regulating rice market.
文摘With the development of economy and the improvement of people's living standards, the use of cars in families has become more and more common, the reliability of the quality of the car in the process of car use is very important. Therefore, in the process of automobile development, automobile enterprises have not paid attention to vehicle reliability tests, including vehicle tests on real roads, virtual roads, environmental reliability and other aspects, so as to ensure the reliability of the vehicle in all aspects, and thus guarantee the driving safety of passengers.
文摘At present, the problem of environmental loss is becoming more and more serious. In order to realize the sustainable development of the environment, it is necessary to increase the research of environmental monitoring technology. If the environment is polluted, it will bring a series of chain reactions. If the specific pollution problem cannot be effectively controlled in a timely manner, it will seriously damage the entire ecosystem. At the same time, it will be irreversible. The environment on which people depend for their survival will also be adversely affected. If it continues to develop for a long time, it will be very disadvantageous to the development of the national economy as a whole. Based on this, this article focuses on the in-depth research and analysis of environmental testing technology and ecological sustainable development.
基金support by the 11th Five Year Key Project of China’s National Scientific Supporting Plan(Grant No.2006BAB04A03)the Hydraulic Engineering Project from the Water Resources Department of Jiangsu Province(Grant No.2010023)
文摘Based on the characteristics of large flow rate , low head , short annual operation time , and high reliability of the city flood-control pumping stations , a new-type shaft tubular pumping system featuring a shaft suction box and a siphon-type discharge passage with a vacuum breaker as the cutoff device was developed , which possesses such advantages as simple structure , reliable cutoff , and high energy performance.Taking some pumping stations as the case studies , in the light of the specified operation conditions , the hydraulic optimal design of the shaft-type tubular pumping system was determined and the optimized shape of the system was recommended.The performance prediction based on the computational fluid dynamics methodology was determined and the model test verification was conducted.The results show that the predicted data agree with the experimental head and efficiency so that both methods can be used to determine the performance of a real pumping station.Finally , the in-situ measurements of a pumping station during the commissioning period further verified that the shaft-type tubular pumping station with a siphon discharge passage is of higher efficiency , more reliable and stable.
基金supported by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(Grant No.2019ZT08G315)the National Natural Science Foundation of China(Grant No.51827901)
文摘With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals of deep mining device need to be developed.Therefore,considering the use of dynamic seals in unique deep mining environments,an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed.The results show that the experimental device can operate stably under a pressure of up to150 MPa and a rotating speed of 76 r/min,and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa.During the operation of the ultra-high-pressure rotating combined dynamic seal,the sealing ring does not show obvious damage,which vouches for its sealing performance.No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0-150 MPa.Therefore,the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth.The research and development of this device can aid future deep energy exploration and exploitation.
文摘The study investigated the relationship among remittances,financial development and economic growth in a panel of 20 sub-Saharan African countries over the period of 2000 and 2015.The study used both Pooled Mean Group and Mean Group/ARDL estimations with panel unit root and cointegration tests.After establishing cointegration,remittances and financial development were found to have positive effects on economic growth both in the short and the long run.The interactive term showed that financial development acted as a substitute in the remittances-growth relationship.Finally,unidirectional causal relationships were found to exist from GDP to remittances and from financial development to GDP.However,no causality existed between remittances and financial development in the SSA countries.
文摘This study investigated the impact of financial sector development on domestic investment in selected countries of the Economic Community of West African States(ECOWAS)for the years 1985–2017.The study employed the augmented mean group procedure,which accounts for country-specific heterogeneity and crosssectional dependence,and the Granger non-causality test to test for causality in the presence of cross-sectional dependence.The results show that(1)The impact of financial sector development on domestic investment depends on the measure of financial sector development utilised;(2)Domestic credit to the private sector has a positive but insignificant impact on domestic investment in ECOWAS,whereas banking intermediation efficiency(i.e.,ability of the banks to transform deposits into credit)and broad money supply negatively and significant influence domestic investment;(3)Cross-country differences exist in the impact of financial sector development on domestic investment in the selected ECOWAS countries;and(4)Domestic credit to the private sector Granger causes domestic investment in ECOWAS.The study recommends careful consideration in the measure of financial development that is utilised as a policy instrument to foster domestic investment.We also highlight the importance of employing country-specific domestic investment policies to avoid blanket policy measures.Domestic credit to the private sector should be given priority when forecasting domestic investment into the future.
文摘Urban-rural interaction and conjunctionaldevelopment is the effective way of harmonizingurban-rural relationship and promoting urban-ruraldevelopment. However, there are differences in thelevel of urban-rural interaction and conjunctionaldevelopment of China. How to measure and reflectthe difference properly is a decision-makingfoundation for optimizing urban-rural developmentof different regions. The paper employs multiplemethods to evaluate and order the urban-ruralinteraction and conjunctional development of 31provinces (municipalities) in China. Kendall’s Wconsistency coefficient is employed to give a consistenttest for the evaluation result series, and the resultsof multiple methods are aggregated as the finalevaluation value. The results reflect the level ofregional urban-rural interaction and conjunctionaldevelopment in China.
