Lime is widely used to modify clayey soils to enhance their physical and chemical properties,and lime-treated soil has become a key material in transportation infrastructure.Chemical reactions were identified through ...Lime is widely used to modify clayey soils to enhance their physical and chemical properties,and lime-treated soil has become a key material in transportation infrastructure.Chemical reactions were identified through laboratory tests from field samples collected from the subgrade after 30 years of operation to understand its long-term performance evolution.Exchangeable calcium,carbonated calcium,and total calcium were quantified using ethylenediaminetetraacetic acid(EDTA)titration,gasometric analysis,and the strong acid extraction method,respectively.These measurements enabled the evaluation of calcium transformation during the pozzolanic reaction,providing a quantitative characterization of pozzolanic progression in the lime-treated clay matrix.Evolutions in pH,electrical conductivity,and salinity were also tracked.Mechanical performance was assessed through maximal shear modulus(Gmax)and unconfined compressive strength(UCS)tests.Then,the microstructure and mineral composition were analyzed via scanning electron microscopy(SEM)and X-ray diffraction(XRD).Furthermore,with an extended curing period,the pH,electrical conductivity,salinity,and exchangeable calcium content were found to decrease gradually.In contrast,the carbonation-related calcium content increased,and the clay mineral structures were significantly altered.The significant increase in Gmax and UCS is attributed to the formation of calcium-aluminate-silicate-hydrate(C-(A)-S-H)for pozzolanic and carbonation reactions where the clay mineral is involved.SEM reveals the curled edges of clay minerals and the formation of a 3D network.Additionally,XRD patterns further confirm the presence of increasing amounts of amorphous phases within the 2θrange of 15°–32°,indicating the progression of the pozzolanic reaction.展开更多
To provide efficient monitoring of web service-based business processes, a web service proxy （WS- proxy） is developed to monitor business activities by monitoring the enactment of services. WS-proxy is deployed as a...To provide efficient monitoring of web service-based business processes, a web service proxy （WS- proxy） is developed to monitor business activities by monitoring the enactment of services. WS-proxy is deployed as an intermediary between internal business processes and external service providers, and it provides a single point of service access with the functions of message routing and content inspection. By using an XPath engine named WS-filter, performance indicators can be generated from service messages for assessing business performance. In the experiments, the feasibility of WS-proxy is verified and it achieves good performance in the monitoring work. The latency introduced by WS-proxy is only about 15% of the overall latency while extracting performance indicators just consumes less than one third of the processing time.展开更多
With rapid advancement of Cloud computing and networking technologies, a wide spectrum of Cloud services have been developed by various providers and utilized by numerous organizations as indispensable ingredients of ...With rapid advancement of Cloud computing and networking technologies, a wide spectrum of Cloud services have been developed by various providers and utilized by numerous organizations as indispensable ingredients of their information systems. Cloud service performance has a significant impact on performance of the future information infrastructure. Thorough evaluation on Cloud service performance is crucial and beneficial to both service providers and consumers; thus forming an active research area. Some key technologies for Cloud computing, such as virtualization and the Service-Oriented Architecture （SOA）, bring in special challenges to service performance evaluation. A tremendous amount of effort has been put by the research community to address these challenges and exciting progress has been made. Among the work on Cloud performance analysis, evaluation approaches developed with a system modeling perspective play an important role. However, related works have been reported in different sections of the literature; thus lacking a big picture that shows the latest status of this area. The objectives of this article is to present a survey that reflects the state of the art of Cloud service performance evaluation from the system modeling perspective. This articles also examines open issues and challenges to the surveyed evaluation approaches and identifies possible opportunities for future research in this important field.展开更多
The flammability of magnesium alloys continues to be a significant barrier to their extensive application,and alloying with rare earth elements(REs)is an effective way to enhance the ignition and fire resistance of Mg...The flammability of magnesium alloys continues to be a significant barrier to their extensive application,and alloying with rare earth elements(REs)is an effective way to enhance the ignition and fire resistance of Mg alloys.Three commercial as-extruded Mg alloys(AZ80 and two Mg-RE alloys:EZ30K and WE43)were directly exposed to flame heating for revealing the evolutions of microstructure and mechanical properties,which is valuable in assessing the post-fire residual service performance of Mg alloy components.Results show that secondary phase dissolution,grain growth,grain boundary melting,alloy melting,and defects generation successively occur during the heating process.After short-term heating for 30 s,the elongation of AZ80 alloy increases significantly by 214%,from 3.82%to 12.01%,with minimal change in strength compared to the initial unheated state.This transformation is attributed to the recovery,grain growth,Mg17Al12 dissolution and dislocation density reduction.Conversely,EZ30K and WE43 alloys exhibit minimal changes in mechanical properties after short-term heating for 60 s,attributed to the pinning effect of REs.However,in subsequent heating states,resolidified microstructure and the presence of defects lead to a noteworthy decrease in both strength and elongation.Among these three alloys,the fire resistance follows this ranking:EZ30K>WE43>AZ80,primarily due to the high thermal conductivity of EZ30K alloy and the thermal stability improved by the addition of REs.展开更多
BACKGROUND: The purpose of the study was to explore the association between posttraumatic stress disorder(PTSD) and work performance of emergency medical services personnel in Karachi, Pakistan.METHODS: Emergency medi...BACKGROUND: The purpose of the study was to explore the association between posttraumatic stress disorder(PTSD) and work performance of emergency medical services personnel in Karachi, Pakistan.METHODS: Emergency medical service personnel were screened for potential PTSD using Impact of Event Scale-Revised(IES-R). Work performance was assessed on the basis of fi ve variables: number of late arrivals to work, number of days absent, number of days sick, adherence to protocol, and patient satisfaction over a period of 3 months. In order to model outcomes like the number of late arrivals to work, days absent and days late, negative binomial regression was applied, whereas logistic regression was applied for adherence to protocol and linear for patient satisfaction scores.RESULTS: Mean scores of PTSD were 24.0±12.2. No association was found between PTSD and work performance measures: number of late arrivals to work(RRadj 0.99; 0.98–1.00), days absent(RRadj 0.98; 0.96–0.99), days sick(RRadj 0.99; 0.98–1.00), adherence to protocol(ORadj 1.01; 0.99–1.04) and patient satisfaction(β 0.001%–0.03%) after adjusting for years of formal schooling, living status, coping mechanism, social support, working hours, years of experience and anxiety or depression.CONCLUSION: No statistically significant association was found between PTSD and work performance amongst EMS personnel in Karachi, Pakistan.展开更多
Combining the principle of antibody concentration with the idea of biological evolution, this paper proposes an adaptive target detection algorithm for cloud service security based on Bio-Inspired Performance Evaluati...Combining the principle of antibody concentration with the idea of biological evolution, this paper proposes an adaptive target detection algorithm for cloud service security based on Bio-Inspired Performance Evaluation Process Algebra(Bio-PEPA). The formal modelling of cloud services is formally modded by Bio-PEPA and the modules are transformed between cloud service internal structures and various components. Then, the security adaptive target detection algorithm of cloud service is divided into two processes, the short-term optimal action selection process which selects the current optimal detective action through the iterative operation of the expected function and the adaptive function, and the long-term detective strategy realized through the updates and eliminations of action planning table. The combination of the two processes reflects the self-adaptability of cloud service system to target detection. The simulating test detects three different kinds of security risks and then analyzes the relationship between the numbers of components with time in the service process. The performance of this method is compared with random detection method and three anomaly detection methods by the cloud service detection experiment. The detection time of this method is 50.1% of three kinds of detection methods and 86.3% of the random detection method. The service success rate is about 15% higher than that of random detection methods. The experimental results show that the algorithm has good time performance and high detection hit rate.展开更多
We successfully fabricated partial Y substituted NdY-Fe-B magnets with nominal compositions of(Nd_(1-x)Y_(x))_(13.80)Fe_(ba1)Al_(0.24)Cu_(0.1)B_(6.04)(at%,x=0,0.1,0.2,0.3,0.4) by powder metallurgy process and the magn...We successfully fabricated partial Y substituted NdY-Fe-B magnets with nominal compositions of(Nd_(1-x)Y_(x))_(13.80)Fe_(ba1)Al_(0.24)Cu_(0.1)B_(6.04)(at%,x=0,0.1,0.2,0.3,0.4) by powder metallurgy process and the magnetic properties as well as service performances of the magnets were also systematically investigated.The phase constituents of the magnets have no obvious variation within the whole range of Y content,while the main phase grains form in-situ core-shell structure where Y gathers in the core and Nd mainly distributes in the shell.Compared with pure Nd-Fe-B magnets,the magnetic performances of Y substituted magnets slightly decrease on account of the poor intrinsic magnetic properties of Y_(2)Fe_(14)B.Fortunately,the μ_(O)M_(r),μ_(O)H_(cj) and(BH)_(max) of the 20 at% Y magnet still remain at a high level of 1.325 kG,1.173 kOe and 342.884 kj/m^(3),which approaches the performances of commercial N45-grade magnet.The service performances of Y substituted magnets indicate that though the surface corrosion products and Vickers hardness of the NdY-Fe-B magnets increase to a certain extent compared to Nd-Fe-B,the magnets with Y substitution still display relatively good service performances.Therefore,on the basis of sacrificing little partial magnetic and service performances,Y substituted Nd can still prepare NdY-Fe-B medium-grade magnets.By this way,we achieve the balanced utilization of rare earth resources,which has significant meanings for the industry and scientific research.展开更多
Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation probl...Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation problem of complex product change plan considering service performance.Firstly,a complex product multi‐layer network with service performance is established for the first time to reveal the impact of change effect propagation on the product service performance.Secondly,the concept of service performance impact(SPI)is defined by decoupling the impact of strongly associated nodes on the service performance in the process of change affect propagation.Then,a triple‐objective selection model of change nodes is established,which includes the three indicators:SPI degree,change cost,and change time.Furthermore,an integer multi‐objective particle swarm optimisation algorithm guided by problem characteristics is developed to solve the model above.Experimental results on the design change problem of a certain type of Skyworth TV verify the effectiveness of the established optimisation model and the proposed P‐BMOPSO algorithm.展开更多
To improve the performance and robustness in service discovery, a self-organizing mechanism for service alliances of Service Providers (SPs) is proposed in this paper. According to the similarity of service content, a...To improve the performance and robustness in service discovery, a self-organizing mechanism for service alliances of Service Providers (SPs) is proposed in this paper. According to the similarity of service content, an SP publishes its services in a partition of SPs to construct connections between highly similar SPs. These SPs constitute a self-organized distributed environment. A self-organizing protocol is designed to ensure the correctness of the construction of the alliances. The protocol consists of four stages - initiating stage, developing stage, developed stage and degradation stage. The experimental results demonstrate that this protocol ensures the self-property. The visualization of alliance developing stages illustrates that sub-alliances are sp lit in balance and self-connected. Compared with the Random Walker algorithm, the time cost and the number of forwarded messages in alliance-based mechanism is lower in service discovery. On three typical topologies (Grid, Random-Graph, Power-Law), the success rate of service discovery is much higher, which shows that self-organized alliances are helpful to enhance the discovery performance.展开更多
The flexibility offered by an Enterprise Service Bus (ESB) in enabling various applications to exchange data makes it a very important middleware layer that is responsible for transporting data in a Service-Oriented A...The flexibility offered by an Enterprise Service Bus (ESB) in enabling various applications to exchange data makes it a very important middleware layer that is responsible for transporting data in a Service-Oriented Architecture (SOA). The popularity of the ESB has given rise to a number of commercial off the shelf (COTS) products as well as open source ESBs. In this study, we evaluated three open source ESBs and compared them both qualitatively and quantitatively. The empirical results were statistically tested to determine the statistical significance of the results.展开更多
As the population of the Internet grows rapidly the development of web technologies becomes extremely important. For the evolvement of Web 2.0, web services are essential. Web services are programs that allow computer...As the population of the Internet grows rapidly the development of web technologies becomes extremely important. For the evolvement of Web 2.0, web services are essential. Web services are programs that allow computers of different platforms on the web to interactively communicate without the need of extra data for human reading interfaces and formats such as web page structures. Since web service is a future trend for the growth of internet, the tools that are used for development is also important. Although there are many choices of web service frameworks to choose from, developers should choose the framework that fits best to their application based on performance, time and effort for the framework. In this project, we chose four common frameworks to compare them in both qualitative and quantitative metrics. After running the tests, the results are statistically analyzed by SAS.展开更多
Taking Chinese A-share listed corporations as sample,this paper studies whether the implementation of financial shared service center,an IT-based financial management practice,can significantly improve the business pe...Taking Chinese A-share listed corporations as sample,this paper studies whether the implementation of financial shared service center,an IT-based financial management practice,can significantly improve the business performance.We conduct Wilcoxon rank sum test and OLS regression model.The results show that there is a significant difference in business performance between the corporations without financial shared service center and the matching samples which have implemented financial shared service.In addition,the positive effect of financial shared services on business performance has a time-lag.As the corporations become adept on financial shared services,their business performance such as profitability,operating ability and growth could be improved steadily.Our study provides suggestions on whether corporations’might upgrade their financial system and how to evaluate the implementation results.展开更多
An architecture for online discovery quantitative models system of service performance management is proposed. The system is capable of constructing the quantitative models without prior knowledge of the managed eleme...An architecture for online discovery quantitative models system of service performance management is proposed. The system is capable of constructing the quantitative models without prior knowledge of the managed elements. The model can be updated continuously in response to the changes made in provider configurations and the evolution of business demands. Due to the existence of strong correlation between the distributed service metrics and response times, linear and hyper-linear quantitative models are constructed, which respectively, use stepwise multiple linear regression algorithm. The simulation results show the effectiveness of a quantitative model constructing system and model constructing algorithms.展开更多
Workload of each service class varies dynamically in the grid environment, making the static service pool size allocation scheme unable to guarantee the QoS requirement of each service class. In this paper, we link th...Workload of each service class varies dynamically in the grid environment, making the static service pool size allocation scheme unable to guarantee the QoS requirement of each service class. In this paper, we link the issue of dynamical service pool size allocation scheme with QoS requirement under the varying workload, and formulate the QoS performance of service requests in the grid environment by queue theory. Combined Lagrangian optimization with a bisearch approach, the problem of optimally allocating service pool size scheme is resolved. Simulation results show efficiency of the optimal service pool size allocation scheme.展开更多
Studies investigating the relationship between size and performance of water service providers are abundant. Yet, this relationship has not been fully addressed in Palestinian water sector, particularly, after the iss...Studies investigating the relationship between size and performance of water service providers are abundant. Yet, this relationship has not been fully addressed in Palestinian water sector, particularly, after the issuance of water law 2014 which calls for merging water providers into large regional utilities. This research evaluates the significant effect of the size of Palestinian water service providers on non-revenue water, staff productivity, collection efficiency, average consumption, average price, operating and maintenance cost, working ratio, and gross profit. The multivariate analysis shows that there are significant differences in working ratio, non-revenue water, staff productivity, average price, and gross profit based on the size. On the other side, no significant differences have been found in average daily consumption, operating and maintenance cost per unit, and collection efficiency based on those providers’ size. The small service providers perform better in non-revenue water, staff productivity, and collection efficiency;wherein, large service providers are more profitable than small service providers. Implications of these findings by conducting further studies will add the value for better merging of the Palestinian water providers and the reforming process.展开更多
TiN coatings were prepared by the novel dual-stage high power impulse magnetron sputtering(HIPIMS)technique under different deposition time conditions,and the effects of microstructure and stress state at different co...TiN coatings were prepared by the novel dual-stage high power impulse magnetron sputtering(HIPIMS)technique under different deposition time conditions,and the effects of microstructure and stress state at different coating growth stages on the mechanical,tribological,and corrosion resistance performance of the coatings were analyzed.Results show that with the prolongation of deposition time from 30 min to 120 min,the surface structure of TiN coating exhibits a round cell structure with tightly doped small and large particles,maintaining the atomic stacking thickening mechanism of deposition-crystallization-growth.When the deposition time increases from 90 min to 120 min,the coating thickness increases from 3884 nm to 4456 nm,and the stress state of coating undergoes the compression-tension transition.When the deposition time is 90 min,TiN coating structure is dense and suffers relatively small compressive stress of−0.54 GPa.The coating has high hardness and elastic modulus,which are 27.5 and 340.2 GPa,respectively.Meanwhile,good tribological properties(average friction coefficient of 0.52,minimum wear rate of 1.68×10^(−4)g/s)and fine corrosion resistance properties(minimum corrosion current density of 1.0632×10^(−8)A·cm^(−2),minimum corrosion rate of 5.5226×10^(−5)mm·A^(−1))can also be obtained for the coatings.展开更多
Existing literature has documented relationships between public service competence and performance as well as some of the mechanisms underlying these links.However,the pathways by which competence are associated with ...Existing literature has documented relationships between public service competence and performance as well as some of the mechanisms underlying these links.However,the pathways by which competence are associated with performance during performing the job in the government official circumstances require further investigation.This study examined a model of the roles of public service competence in performance with a focus on social sensitivity as mediators in the putative chain of events linking the competence with performance.The sample comprised 155 camat(sub-district head)in West Java,Indonesia.A cross-sectional design was used with measures of all variables that administered.In structural equations analyses,competence was associated with greater social sensitivity and greater job performance.Furthermore,public service competence was indirectly associated with performance via the social sensitivity.The findings of this study replicate existing theory concerning the direct and indirect relationships of competence and performance,and extend these theory by elucidating the pathways through which predictor is linked with outcome during a typically sensitivity condition.展开更多
The current Researches on performance of pension service mainly including establishing performance evaluation index system of pension service, evaluating performance of the participants＇ activities, or assessing qual...The current Researches on performance of pension service mainly including establishing performance evaluation index system of pension service, evaluating performance of the participants＇ activities, or assessing quality of pension service. Building index system or implementing performance assessment is just a part of performance management. Performance management is not a single course of conduct, but a complex circulatory system consisted by many links and procedures. It is an important way to make the work of pension service strategical by improving research on performance of pension service from assessment to management展开更多
Aiming at the problems in reality,this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University,from t...Aiming at the problems in reality,this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University,from the aspects of public sports service system,facilities planning and social sports industrialization.In order to connecting the school's physical education and public sports services as seamlessly as possible,it becomes a union for the coordination with each other,and provides the national fitness campaign with rapid and healthy conditions.展开更多
This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and ca...This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and case study, so as to promote the quality of demonstration area constructed for modem public sports services, truly show the social application value of the construction of demonstration area for modem public sports services, and achieve national fitness and the development of public sports.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42302311)the ARC Discovery Project Program(Grant Nos.DP210100437 and DP230100126).
文摘Lime is widely used to modify clayey soils to enhance their physical and chemical properties,and lime-treated soil has become a key material in transportation infrastructure.Chemical reactions were identified through laboratory tests from field samples collected from the subgrade after 30 years of operation to understand its long-term performance evolution.Exchangeable calcium,carbonated calcium,and total calcium were quantified using ethylenediaminetetraacetic acid(EDTA)titration,gasometric analysis,and the strong acid extraction method,respectively.These measurements enabled the evaluation of calcium transformation during the pozzolanic reaction,providing a quantitative characterization of pozzolanic progression in the lime-treated clay matrix.Evolutions in pH,electrical conductivity,and salinity were also tracked.Mechanical performance was assessed through maximal shear modulus(Gmax)and unconfined compressive strength(UCS)tests.Then,the microstructure and mineral composition were analyzed via scanning electron microscopy(SEM)and X-ray diffraction(XRD).Furthermore,with an extended curing period,the pH,electrical conductivity,salinity,and exchangeable calcium content were found to decrease gradually.In contrast,the carbonation-related calcium content increased,and the clay mineral structures were significantly altered.The significant increase in Gmax and UCS is attributed to the formation of calcium-aluminate-silicate-hydrate(C-(A)-S-H)for pozzolanic and carbonation reactions where the clay mineral is involved.SEM reveals the curled edges of clay minerals and the formation of a 3D network.Additionally,XRD patterns further confirm the presence of increasing amounts of amorphous phases within the 2θrange of 15°–32°,indicating the progression of the pozzolanic reaction.
基金The National Natural Science Foundation of China(No60473078)
文摘To provide efficient monitoring of web service-based business processes, a web service proxy （WS- proxy） is developed to monitor business activities by monitoring the enactment of services. WS-proxy is deployed as an intermediary between internal business processes and external service providers, and it provides a single point of service access with the functions of message routing and content inspection. By using an XPath engine named WS-filter, performance indicators can be generated from service messages for assessing business performance. In the experiments, the feasibility of WS-proxy is verified and it achieves good performance in the monitoring work. The latency introduced by WS-proxy is only about 15% of the overall latency while extracting performance indicators just consumes less than one third of the processing time.
文摘With rapid advancement of Cloud computing and networking technologies, a wide spectrum of Cloud services have been developed by various providers and utilized by numerous organizations as indispensable ingredients of their information systems. Cloud service performance has a significant impact on performance of the future information infrastructure. Thorough evaluation on Cloud service performance is crucial and beneficial to both service providers and consumers; thus forming an active research area. Some key technologies for Cloud computing, such as virtualization and the Service-Oriented Architecture （SOA）, bring in special challenges to service performance evaluation. A tremendous amount of effort has been put by the research community to address these challenges and exciting progress has been made. Among the work on Cloud performance analysis, evaluation approaches developed with a system modeling perspective play an important role. However, related works have been reported in different sections of the literature; thus lacking a big picture that shows the latest status of this area. The objectives of this article is to present a survey that reflects the state of the art of Cloud service performance evaluation from the system modeling perspective. This articles also examines open issues and challenges to the surveyed evaluation approaches and identifies possible opportunities for future research in this important field.
基金Project supported by the National Key Research and Development Program of China(2021YFB3501002)the National Science and Technology Major Project(J2019-Ⅷ-0003-0165)+1 种基金the National Natural Science Foundation of China(52301059)the Shanghai Post-doctoral Excellence Program(2023372)。
文摘The flammability of magnesium alloys continues to be a significant barrier to their extensive application,and alloying with rare earth elements(REs)is an effective way to enhance the ignition and fire resistance of Mg alloys.Three commercial as-extruded Mg alloys(AZ80 and two Mg-RE alloys:EZ30K and WE43)were directly exposed to flame heating for revealing the evolutions of microstructure and mechanical properties,which is valuable in assessing the post-fire residual service performance of Mg alloy components.Results show that secondary phase dissolution,grain growth,grain boundary melting,alloy melting,and defects generation successively occur during the heating process.After short-term heating for 30 s,the elongation of AZ80 alloy increases significantly by 214%,from 3.82%to 12.01%,with minimal change in strength compared to the initial unheated state.This transformation is attributed to the recovery,grain growth,Mg17Al12 dissolution and dislocation density reduction.Conversely,EZ30K and WE43 alloys exhibit minimal changes in mechanical properties after short-term heating for 60 s,attributed to the pinning effect of REs.However,in subsequent heating states,resolidified microstructure and the presence of defects lead to a noteworthy decrease in both strength and elongation.Among these three alloys,the fire resistance follows this ranking:EZ30K>WE43>AZ80,primarily due to the high thermal conductivity of EZ30K alloy and the thermal stability improved by the addition of REs.
基金partially supported through the Johns Hopkins-Pakistan International Collaborative Trauma and Injury Research Training program(grant number 2D43-TW007-292)from the Fogarty International Center of the United States,National Institutes of Healthpartially supported from department of Community Health Sciences,Aga Khan University,Karachi,Pakistan
文摘BACKGROUND: The purpose of the study was to explore the association between posttraumatic stress disorder(PTSD) and work performance of emergency medical services personnel in Karachi, Pakistan.METHODS: Emergency medical service personnel were screened for potential PTSD using Impact of Event Scale-Revised(IES-R). Work performance was assessed on the basis of fi ve variables: number of late arrivals to work, number of days absent, number of days sick, adherence to protocol, and patient satisfaction over a period of 3 months. In order to model outcomes like the number of late arrivals to work, days absent and days late, negative binomial regression was applied, whereas logistic regression was applied for adherence to protocol and linear for patient satisfaction scores.RESULTS: Mean scores of PTSD were 24.0±12.2. No association was found between PTSD and work performance measures: number of late arrivals to work(RRadj 0.99; 0.98–1.00), days absent(RRadj 0.98; 0.96–0.99), days sick(RRadj 0.99; 0.98–1.00), adherence to protocol(ORadj 1.01; 0.99–1.04) and patient satisfaction(β 0.001%–0.03%) after adjusting for years of formal schooling, living status, coping mechanism, social support, working hours, years of experience and anxiety or depression.CONCLUSION: No statistically significant association was found between PTSD and work performance amongst EMS personnel in Karachi, Pakistan.
基金Supported by the National Natural Science Foundation of China(61202458,61403109)the Natural Science Foundation of Heilongjiang Province of China(F2017021)and the Harbin Science and Technology Innovation Research Funds(2016RAQXJ036)
文摘Combining the principle of antibody concentration with the idea of biological evolution, this paper proposes an adaptive target detection algorithm for cloud service security based on Bio-Inspired Performance Evaluation Process Algebra(Bio-PEPA). The formal modelling of cloud services is formally modded by Bio-PEPA and the modules are transformed between cloud service internal structures and various components. Then, the security adaptive target detection algorithm of cloud service is divided into two processes, the short-term optimal action selection process which selects the current optimal detective action through the iterative operation of the expected function and the adaptive function, and the long-term detective strategy realized through the updates and eliminations of action planning table. The combination of the two processes reflects the self-adaptability of cloud service system to target detection. The simulating test detects three different kinds of security risks and then analyzes the relationship between the numbers of components with time in the service process. The performance of this method is compared with random detection method and three anomaly detection methods by the cloud service detection experiment. The detection time of this method is 50.1% of three kinds of detection methods and 86.3% of the random detection method. The service success rate is about 15% higher than that of random detection methods. The experimental results show that the algorithm has good time performance and high detection hit rate.
基金Project supported by the Key Research and Development Program of Shandong Province (2019JZZY010321)the Major Project of "Science and Technology Innovation 2025" in Ningbo City (2020Z050)+1 种基金Ningbo Natural Science Foundation (202003N4352)the Kunpeng Project in Zhejiang Province and National Natural Science Foundation of China (52101238)。
文摘We successfully fabricated partial Y substituted NdY-Fe-B magnets with nominal compositions of(Nd_(1-x)Y_(x))_(13.80)Fe_(ba1)Al_(0.24)Cu_(0.1)B_(6.04)(at%,x=0,0.1,0.2,0.3,0.4) by powder metallurgy process and the magnetic properties as well as service performances of the magnets were also systematically investigated.The phase constituents of the magnets have no obvious variation within the whole range of Y content,while the main phase grains form in-situ core-shell structure where Y gathers in the core and Nd mainly distributes in the shell.Compared with pure Nd-Fe-B magnets,the magnetic performances of Y substituted magnets slightly decrease on account of the poor intrinsic magnetic properties of Y_(2)Fe_(14)B.Fortunately,the μ_(O)M_(r),μ_(O)H_(cj) and(BH)_(max) of the 20 at% Y magnet still remain at a high level of 1.325 kG,1.173 kOe and 342.884 kj/m^(3),which approaches the performances of commercial N45-grade magnet.The service performances of Y substituted magnets indicate that though the surface corrosion products and Vickers hardness of the NdY-Fe-B magnets increase to a certain extent compared to Nd-Fe-B,the magnets with Y substitution still display relatively good service performances.Therefore,on the basis of sacrificing little partial magnetic and service performances,Y substituted Nd can still prepare NdY-Fe-B medium-grade magnets.By this way,we achieve the balanced utilization of rare earth resources,which has significant meanings for the industry and scientific research.
基金supported by The National Key Research and Development Program of China(No.2020YFB1708200).
文摘Design change is an inevitable part of the product development process.This study proposes an improved binary multi‐objective PSO algorithm guided by problem char-acteristics(P‐BMOPSO)to solve the optimisation problem of complex product change plan considering service performance.Firstly,a complex product multi‐layer network with service performance is established for the first time to reveal the impact of change effect propagation on the product service performance.Secondly,the concept of service performance impact(SPI)is defined by decoupling the impact of strongly associated nodes on the service performance in the process of change affect propagation.Then,a triple‐objective selection model of change nodes is established,which includes the three indicators:SPI degree,change cost,and change time.Furthermore,an integer multi‐objective particle swarm optimisation algorithm guided by problem characteristics is developed to solve the model above.Experimental results on the design change problem of a certain type of Skyworth TV verify the effectiveness of the established optimisation model and the proposed P‐BMOPSO algorithm.
基金This paper was supported by the Natural Science Foundation of China under Grants No. 61170053, No. 61100205 the Nat- ural Science Foundation of Beijing under Grant No. 4112027 the Natural Science Foundation of Hebei under Grant No. F2009000929. The authors would like to thank the anony- mous reviewers for their helpful comments from which the preparation for this version of the paper has benefited.
文摘To improve the performance and robustness in service discovery, a self-organizing mechanism for service alliances of Service Providers (SPs) is proposed in this paper. According to the similarity of service content, an SP publishes its services in a partition of SPs to construct connections between highly similar SPs. These SPs constitute a self-organized distributed environment. A self-organizing protocol is designed to ensure the correctness of the construction of the alliances. The protocol consists of four stages - initiating stage, developing stage, developed stage and degradation stage. The experimental results demonstrate that this protocol ensures the self-property. The visualization of alliance developing stages illustrates that sub-alliances are sp lit in balance and self-connected. Compared with the Random Walker algorithm, the time cost and the number of forwarded messages in alliance-based mechanism is lower in service discovery. On three typical topologies (Grid, Random-Graph, Power-Law), the success rate of service discovery is much higher, which shows that self-organized alliances are helpful to enhance the discovery performance.
文摘The flexibility offered by an Enterprise Service Bus (ESB) in enabling various applications to exchange data makes it a very important middleware layer that is responsible for transporting data in a Service-Oriented Architecture (SOA). The popularity of the ESB has given rise to a number of commercial off the shelf (COTS) products as well as open source ESBs. In this study, we evaluated three open source ESBs and compared them both qualitatively and quantitatively. The empirical results were statistically tested to determine the statistical significance of the results.
文摘As the population of the Internet grows rapidly the development of web technologies becomes extremely important. For the evolvement of Web 2.0, web services are essential. Web services are programs that allow computers of different platforms on the web to interactively communicate without the need of extra data for human reading interfaces and formats such as web page structures. Since web service is a future trend for the growth of internet, the tools that are used for development is also important. Although there are many choices of web service frameworks to choose from, developers should choose the framework that fits best to their application based on performance, time and effort for the framework. In this project, we chose four common frameworks to compare them in both qualitative and quantitative metrics. After running the tests, the results are statistically analyzed by SAS.
基金supported by University-Industry Collaborative Education Program by the Ministry of Education of China under Grant No.202002314026.
文摘Taking Chinese A-share listed corporations as sample,this paper studies whether the implementation of financial shared service center,an IT-based financial management practice,can significantly improve the business performance.We conduct Wilcoxon rank sum test and OLS regression model.The results show that there is a significant difference in business performance between the corporations without financial shared service center and the matching samples which have implemented financial shared service.In addition,the positive effect of financial shared services on business performance has a time-lag.As the corporations become adept on financial shared services,their business performance such as profitability,operating ability and growth could be improved steadily.Our study provides suggestions on whether corporations’might upgrade their financial system and how to evaluate the implementation results.
基金This paper is supported by the National Natural Science Foundation of China (Grant No. 90304006),the Spe-cialized Research Fund for the Doctoral Program of Higher Education (SRFDP)(Grant No. 20020698018).
文摘An architecture for online discovery quantitative models system of service performance management is proposed. The system is capable of constructing the quantitative models without prior knowledge of the managed elements. The model can be updated continuously in response to the changes made in provider configurations and the evolution of business demands. Due to the existence of strong correlation between the distributed service metrics and response times, linear and hyper-linear quantitative models are constructed, which respectively, use stepwise multiple linear regression algorithm. The simulation results show the effectiveness of a quantitative model constructing system and model constructing algorithms.
基金Project supported by the National-High-Technology Research and Development Program of China (Grant No.2004AA111110)
文摘Workload of each service class varies dynamically in the grid environment, making the static service pool size allocation scheme unable to guarantee the QoS requirement of each service class. In this paper, we link the issue of dynamical service pool size allocation scheme with QoS requirement under the varying workload, and formulate the QoS performance of service requests in the grid environment by queue theory. Combined Lagrangian optimization with a bisearch approach, the problem of optimally allocating service pool size scheme is resolved. Simulation results show efficiency of the optimal service pool size allocation scheme.
文摘Studies investigating the relationship between size and performance of water service providers are abundant. Yet, this relationship has not been fully addressed in Palestinian water sector, particularly, after the issuance of water law 2014 which calls for merging water providers into large regional utilities. This research evaluates the significant effect of the size of Palestinian water service providers on non-revenue water, staff productivity, collection efficiency, average consumption, average price, operating and maintenance cost, working ratio, and gross profit. The multivariate analysis shows that there are significant differences in working ratio, non-revenue water, staff productivity, average price, and gross profit based on the size. On the other side, no significant differences have been found in average daily consumption, operating and maintenance cost per unit, and collection efficiency based on those providers’ size. The small service providers perform better in non-revenue water, staff productivity, and collection efficiency;wherein, large service providers are more profitable than small service providers. Implications of these findings by conducting further studies will add the value for better merging of the Palestinian water providers and the reforming process.
基金Xi'an Science and Technology Plan Project(23GXFW0055)Shaanxi Provincial Natural Science Basic Research Program Project(2024JC-YBQN-0525)National Natural Science Foundation of China(52001251)。
文摘TiN coatings were prepared by the novel dual-stage high power impulse magnetron sputtering(HIPIMS)technique under different deposition time conditions,and the effects of microstructure and stress state at different coating growth stages on the mechanical,tribological,and corrosion resistance performance of the coatings were analyzed.Results show that with the prolongation of deposition time from 30 min to 120 min,the surface structure of TiN coating exhibits a round cell structure with tightly doped small and large particles,maintaining the atomic stacking thickening mechanism of deposition-crystallization-growth.When the deposition time increases from 90 min to 120 min,the coating thickness increases from 3884 nm to 4456 nm,and the stress state of coating undergoes the compression-tension transition.When the deposition time is 90 min,TiN coating structure is dense and suffers relatively small compressive stress of−0.54 GPa.The coating has high hardness and elastic modulus,which are 27.5 and 340.2 GPa,respectively.Meanwhile,good tribological properties(average friction coefficient of 0.52,minimum wear rate of 1.68×10^(−4)g/s)and fine corrosion resistance properties(minimum corrosion current density of 1.0632×10^(−8)A·cm^(−2),minimum corrosion rate of 5.5226×10^(−5)mm·A^(−1))can also be obtained for the coatings.
文摘Existing literature has documented relationships between public service competence and performance as well as some of the mechanisms underlying these links.However,the pathways by which competence are associated with performance during performing the job in the government official circumstances require further investigation.This study examined a model of the roles of public service competence in performance with a focus on social sensitivity as mediators in the putative chain of events linking the competence with performance.The sample comprised 155 camat(sub-district head)in West Java,Indonesia.A cross-sectional design was used with measures of all variables that administered.In structural equations analyses,competence was associated with greater social sensitivity and greater job performance.Furthermore,public service competence was indirectly associated with performance via the social sensitivity.The findings of this study replicate existing theory concerning the direct and indirect relationships of competence and performance,and extend these theory by elucidating the pathways through which predictor is linked with outcome during a typically sensitivity condition.
文摘The current Researches on performance of pension service mainly including establishing performance evaluation index system of pension service, evaluating performance of the participants＇ activities, or assessing quality of pension service. Building index system or implementing performance assessment is just a part of performance management. Performance management is not a single course of conduct, but a complex circulatory system consisted by many links and procedures. It is an important way to make the work of pension service strategical by improving research on performance of pension service from assessment to management
文摘Aiming at the problems in reality,this paper makes a systematic analysis based on the investigation and research on the current situation of the sports resources in public sports service of Changzhou University,from the aspects of public sports service system,facilities planning and social sports industrialization.In order to connecting the school's physical education and public sports services as seamlessly as possible,it becomes a union for the coordination with each other,and provides the national fitness campaign with rapid and healthy conditions.
文摘This paper introduces the third party performance evaluation in the construction of demonstration area for modem public sports services in Changzhou through research methods such as literature, expert interview and case study, so as to promote the quality of demonstration area constructed for modem public sports services, truly show the social application value of the construction of demonstration area for modem public sports services, and achieve national fitness and the development of public sports.
