The reliability of information systems(IS)is a key factor in the sustainable operation of modern digital services.However,existing assessment methods remain fragmented and are often limited to individual indicators or...The reliability of information systems(IS)is a key factor in the sustainable operation of modern digital services.However,existing assessment methods remain fragmented and are often limited to individual indicators or expert judgments.This paper proposes a hybridmethodology for a comprehensive assessment of IS reliability based on the integration of the international standard ISO/IEC 25010:2023,multicriteria analysismethods(ARAS,CoCoSo,and TOPSIS),and theXGBoostmachine learning algorithmfor missing data imputation.Thestructure of the ISO/IEC 25010 standard is used to formalize reliability criteria and subcriteria,while theAHP method allows for the calculation of their weighting coefficients based on expert assessments.The XGBoost algorithm ensures the correct filling of gaps in the source data,increasing the completeness and reliability of the subsequent assessment.The resulting weighted indicators are aggregated using threeMCDMmethods,after which an integral reliability indicator is formed as a percentage.The methodology was tested on six real-world information systems with different architectures.The results demonstrated high consistency between the ARAS,CoCoSo,and TOPSISmethods,as well as the stability of the final rating when the criterion weights vary by±10%.The proposed approach provides a reproducible,transparent,and objective assessment of information system reliability and can be used to identify system bottlenecks,make modernization decisions,and manage the quality of digital infrastructure.展开更多
The probabilistic stability evolution analysis of reservoir bank slopes is a crucial aspect of risk assessment,with core challenges including the consideration of deformation mechanisms and accurate determination of m...The probabilistic stability evolution analysis of reservoir bank slopes is a crucial aspect of risk assessment,with core challenges including the consideration of deformation mechanisms and accurate determination of mechanical parameters.In this study,a novel time-varying reliability analysis framework based on sequential Bayesian updating of mechanical parameters is proposed.The inverse parameters account for damage time-dependent behavior,incorporating water effect and a strain-driven softening-hardening process that depends on sliding states.The likelihood function is enhanced to simultaneously consider observation error,surrogate model prediction error,and model structural error,with the introduction of physical penalty.Exploration of the high-dimensional parameter space is achieved via the Hamiltonian Monte Carlo(HMC)method and the physics knowledge-based time-dependent deformation surrogate model.The time-varying reliability analysis of the slope is performed using the multi-grid method.Taking a reservoir bank slope as a case study,the sequential updating of 12 mechanical parameters is conducted based on deformation time series from 16 monitoring points,thereby validating the proposed framework.The results indicate that the proposed framework effectively captures the posterior distribution of mechanical parameters,with the case slope remaining in a critically stable state after overall sliding,showing a high failure probability.Introducing model structural error can reduce parameter compensation,and a reasonable sequential updating step size can improve inversion accuracy.展开更多
The evolution of cities into digitally managed environments requires computational systems that can operate in real time while supporting predictive and adaptive infrastructure management.Earlier approaches have often...The evolution of cities into digitally managed environments requires computational systems that can operate in real time while supporting predictive and adaptive infrastructure management.Earlier approaches have often advanced one dimension—such as Internet of Things(IoT)-based data acquisition,Artificial Intelligence(AI)-driven analytics,or digital twin visualization—without fully integrating these strands into a single operational loop.As a result,many existing solutions encounter bottlenecks in responsiveness,interoperability,and scalability,while also leaving concerns about data privacy unresolved.This research introduces a hybrid AI–IoT–Digital Twin framework that combines continuous sensing,distributed intelligence,and simulation-based decision support.The design incorporates multi-source sensor data,lightweight edge inference through Convolutional Neural Networks(CNN)and Long ShortTerm Memory(LSTM)models,and federated learning enhanced with secure aggregation and differential privacy to maintain confidentiality.A digital twin layer extends these capabilities by simulating city assets such as traffic flows and water networks,generating what-if scenarios,and issuing actionable control signals.Complementary modules,including model compression and synchronization protocols,are embedded to ensure reliability in bandwidth-constrained and heterogeneous urban environments.The framework is validated in two urban domains:traffic management,where it adapts signal cycles based on real-time congestion patterns,and pipeline monitoring,where it anticipates leaks through pressure and vibration data.Experimental results show a 28%reduction in response time,a 35%decrease in maintenance costs,and a marked reduction in false positives relative to conventional baselines.The architecture also demonstrates stability across 50+edge devices under federated training and resilience to uneven node participation.The proposed system provides a scalable and privacy-aware foundation for predictive urban infrastructure management.By closing the loop between sensing,learning,and control,it reduces operator dependence,enhances resource efficiency,and supports transparent governance models for emerging smart cities.展开更多
The stochastic boundary element method(SBEM)is developed in this paper for 3D problems with body forces and reliability analysis of engineering structures.The integral equations of SBEM are established by the approach...The stochastic boundary element method(SBEM)is developed in this paper for 3D problems with body forces and reliability analysis of engineering structures.The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables,considering the yield limit,rotation speeds and material density to be the fundamental stochastic variables.Through analyzing a numerical example and a turbo-disk of an aeroengine,the results show that the method developed is successful.展开更多
In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connectio...In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connection and parallel connection） of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up.展开更多
An integrated intelligent management is presented to help organizations manage many heterogeneous resources in their information system. A general architecture of management for information system reliability is propo...An integrated intelligent management is presented to help organizations manage many heterogeneous resources in their information system. A general architecture of management for information system reliability is proposed, and the architecture from two aspects, process model and hierarchical model, described. Data mining techniques are used in data analysis. A data analysis system applicable to real-time data analysis is developed by improved data mining on the critical processes. The framework of the integrated management for information system reliability based on real-time data mining is illustrated, and the development of integrated and intelligent management of information system discussed.展开更多
On the basis of analyzing the reliability of the organization’ management chain of the large and medium- sized project in the construction period, the paper studies the factors influencing the reliability of the orga...On the basis of analyzing the reliability of the organization’ management chain of the large and medium- sized project in the construction period, the paper studies the factors influencing the reliability of the organi-zation management chain, which, corresponding to four elements of management chain – “Management Loop”, “Management Link”, “Management Chain”, and “Management Network”, can be summarized as project main body, interface management, connection sequence and management model. The paper then re-searches on the specific influencing factors from the above-mentioned four aspects.展开更多
A stochastic boundary element method (SBEM) is developed for 3-Dproblems with body forces. The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables, con...A stochastic boundary element method (SBEM) is developed for 3-Dproblems with body forces. The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables, considering the strengthlimit, rotation speeds and material density to be the fundamental stochastic variables.The method developed is applied to analyzing the strength reliability of the turbo diskof an aero-engine.展开更多
Risk precontrol management system of coal mines safety( RPMSCS) provides a set of preventive safety management strategy for high-risk coal industries, which has captured extensive attentions. Fundamentally,there are s...Risk precontrol management system of coal mines safety( RPMSCS) provides a set of preventive safety management strategy for high-risk coal industries, which has captured extensive attentions. Fundamentally,there are several membership systems with subsystems in the management system, and the subsystem reliability has an important influence on the management system performance. Through analyzing the structure characteristics of the management system,the phase type distribution was employed to analyze its subsystem reliability by considering repair process and three states including working,fail-abnormal,and fail-emergency states. The reliability indices of the subsystem were derived respectively,including the probabilities that the subsystem in three states,mean time to the first failure, mean time to first failemergency,mean working time to first fail-emergency,and mean maintenance time to the first fail-emergency, are derived respectively. The probabilities of the membership systems and the management system in three states were also derived. Some numerical examples were used to show the procedures. The result is important for better understanding the management system operation and improving its operational performance from the respect of system reliability.展开更多
In order to take into account the uncertainties linked to the variables in the evaluation of the statistical properties of structural response, a reliability approach with probabilistic aspect was considered. This is ...In order to take into account the uncertainties linked to the variables in the evaluation of the statistical properties of structural response, a reliability approach with probabilistic aspect was considered. This is called the Probabilistic Transformation Method (PTM). This method is readily applicable when the function between the input and the output of the system is explicit. However, the situation is much more involved when it is necessary to perform the evaluation of implicit function between the input and the output of the system through numerical models. In this work, we propose a technique that combines Finite Element Analysis (FEA) and Probabilistic Transformation Method (PTM) to evaluate the Probability Density Function (PDF) of response where the function between the input and the output of the system is implicit. This technique is based on the numerical simulations of the Finite Element Analysis (FEA) and the Probabilistic Transformation Method (PTM) using an interface between Finite Element software and Matlab. Some problems of structures are treated in order to prove the applicability of the proposed technique. Moreover, the obtained results are compared to those obtained by the reference method of Monte Carlo. A second aim of this work is to develop an algorithm of global optimization using the local method SQP, because of its effectiveness and its rapidity of convergence. For this reason, we have combined the method SQP with the Multi start method. This developed algorithm is tested on test functions comparing with other methods such as the method of Particle Swarm Optimization (PSO). In order to test the applicability of the proposed approach, a structure is optimized under reliability constraints.展开更多
To achieve excellent production capability and maintain high security for nuclear power stations, equipment reliability is studied as a key issue. As the main branch, equipment reliability management is considered as ...To achieve excellent production capability and maintain high security for nuclear power stations, equipment reliability is studied as a key issue. As the main branch, equipment reliability management is considered as an effective approach to make plant management strategy and organize routine work. Some achievements on research and application of equipment reliability management at Daya Bay Nuclear Power Station are introduced in this paper. By studying and implementing 1NPO （Institute of Nuclear Power Operations） AP-913 equipment reliability process, reliability-centered maintenance （RCM）, critical component management （CCM）, and many other similar methods, equipment reliability management system has been established at Daya Bay. And by continuous effort on improving application effect of these technologies, some innovation has also been made. Some innovative products, such as iSOM Intelligent Expert System, reliability and technique centered maintenance （RtCM）, predictive maintenance system （PdM）, and so on, have been developed. Based on these achievements, Daya Bay Nuclear Power Station has achieved excellent operation performance and won several prizes in WANO （World Association of Nuclear Operators） competition every year.展开更多
Software reliability models describe the failure behavior of the software. The models are used to evaluate the software quantitatively. They assess the reliability of the software by predicting faults or failures for ...Software reliability models describe the failure behavior of the software. The models are used to evaluate the software quantitatively. They assess the reliability of the software by predicting faults or failures for a software. Reliability is one of important quality attributes of the software in which software end user is more interested rather than the software developer. Hence, the performance of a software can be improved by incorporating important quality attributes like reliability, maintainability and availability of the software along with performance attributes like response time and throughput. The paper discusses about the role played by important software reliability models in analyzing the failure prediction of the software. It also explores the strong relationship that exists between quality attributes and performance attributes. With some illustrations highlighting the necessity of in-depth understanding of the link that exists between reliability and performance of the software. The derived knowledge helps in improving the performance of the software sustainably over a period of time and manage the software more effectively.展开更多
In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facil...In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facilitate this study. First, methods used for such studies and their results at global level were reviewed. Then Australian specific methods of study and findings were reviewed. More commonly, both globally and in Australia, simulations using long-term real data on selected climatic scenarios of global climatic models are projected for long-term future trends. The validity and certainty of predicted occurrences depend upon the closeness of real time data with scenarios to which they are projected. Even with these limitations, projections of already rising temperatures and declining rainfall on surface water and ground water availabilities show gradual decline in water availability leading to water stress both for human communities and ecosystems The role of human-induced emissions in hastening the degradation process has also been investigated. Conserving all available water, practising efficient water consumption and prudent water policies only can provide some relief from what is inevitable.展开更多
With the rapid development of the social economy,the pace of urban-rural integration construction has been accelerating continuously.From the actual situation at this stage,it is necessary to maintain the sound relati...With the rapid development of the social economy,the pace of urban-rural integration construction has been accelerating continuously.From the actual situation at this stage,it is necessary to maintain the sound relationship of coordination,interaction and mutual advance between the city and the village.In the process of building urban-rural integration,we should focus on strengthening the development of land management,so as to improve the rationality of land development and utilization,and maximize the value of land while protecting rural farmland resources.The author explores and analyzes the problems existing in the land management work in the urban-rural integration construction.An effective way is put forward to carry out land management work in urban and rural integration construction,which contributes to the improvement of the quality of land management work.展开更多
The quantity of bio-laboratories and bio-factories in Uzbekistan increases every year.In 1970,there were only 4,in 1971,16,in 1985,710,in 1990,774,and in 2000,790.At present there
Solid waste management has become the greatest public health problem facing many urban and semi-urban areas in Ghana. Great wealth can be generated from wastes if managed effectively but also has high probability of c...Solid waste management has become the greatest public health problem facing many urban and semi-urban areas in Ghana. Great wealth can be generated from wastes if managed effectively but also has high probability of causing serious health and environmental problems if not effectively managed. The study sought to determine factors militating against domestic solid waste management in Hohoe, possible ways of curbing them and also to assess the methods of domestic solid waste management. This study used descriptive cross-sectional survey and structured questionnaire to obtain the required information from respondents. A total number of 403 respondents were recruited into the study. The data collected were entered and analyzed using Statistical Package for Social Sciences version 20. The relationships between socio-demographic characteristics of the respondents and their use or non-use of apt domestic solid waste disposal methods were examined using chi-square analysis. The study found that 44% of respondents disposed domestic waste into central skip over dustbins. Spilled over of skip over dustbin has caused 8% of respondents to practice open burning. 7% dumped on undeveloped building plots, 5% dumped elsewhere, and 3% dumped into the river course. About 78% of respondents reported that mobilization of cleanups was irregular. The result from the study also showed a statistical significant association between practice of domestic solid waste management and religion [χ<sup>2</sup> (2, 403) = 60.9484, p α = 5%]. About 96% of Christians practiced good methods of domestic solid waste management compared to 4% of Muslims. The findings painted a gloomy picture of poor domestic solid waste management practice among the respondents in the study communities.展开更多
During the construction process of the construction project,the construction technology management work can improve the overall quality of the project construction.In the context of increasingly fierce competition in ...During the construction process of the construction project,the construction technology management work can improve the overall quality of the project construction.In the context of increasingly fierce competition in the construction market,construction enterprises should strengthen the management of construction technology,enhance their technical level and market competitiveness,and promote the development of the construction market[1].The paper mainly analyzes the optimization methods of build-Keywords:ing construction technology management.展开更多
Fatigue analysis of engine turbine blade is an essential issue.Due to various uncertainties during the manufacture and operation,the fatigue damage and life of turbine blade present randomness.In this study,the random...Fatigue analysis of engine turbine blade is an essential issue.Due to various uncertainties during the manufacture and operation,the fatigue damage and life of turbine blade present randomness.In this study,the randomness of structural parameters,working condition and vibration environment are considered for fatigue life predication and reliability assessment.First,the lowcycle fatigue problem is modelled as stochastic static system with random parameters,while the high-cycle fatigue problem is considered as stochastic dynamic system under random excitations.Then,to deal with the two failure modes,the novel Direct Probability Integral Method(DPIM)is proposed,which is efficient and accurate for solving stochastic static and dynamic systems.The probability density functions of accumulated damage and fatigue life of turbine blade for low-cycle and high-cycle fatigue problems are achieved,respectively.Furthermore,the time–frequency hybrid method is advanced to enhance the computational efficiency for governing equation of system.Finally,the results of typical examples demonstrate high accuracy and efficiency of the proposed method by comparison with Monte Carlo simulation and other methods.It is indicated that the DPIM is a unified method for predication of random fatigue life for low-cycle and highcycle fatigue problems.The rotational speed,density,fatigue strength coefficient,and fatigue plasticity index have a high sensitivity to fatigue reliability of engine turbine blade.展开更多
基金the financial support of the Ministry of Science and Higher Education of the Republic of Kazakhstan,grant No.AP25793823.
文摘The reliability of information systems(IS)is a key factor in the sustainable operation of modern digital services.However,existing assessment methods remain fragmented and are often limited to individual indicators or expert judgments.This paper proposes a hybridmethodology for a comprehensive assessment of IS reliability based on the integration of the international standard ISO/IEC 25010:2023,multicriteria analysismethods(ARAS,CoCoSo,and TOPSIS),and theXGBoostmachine learning algorithmfor missing data imputation.Thestructure of the ISO/IEC 25010 standard is used to formalize reliability criteria and subcriteria,while theAHP method allows for the calculation of their weighting coefficients based on expert assessments.The XGBoost algorithm ensures the correct filling of gaps in the source data,increasing the completeness and reliability of the subsequent assessment.The resulting weighted indicators are aggregated using threeMCDMmethods,after which an integral reliability indicator is formed as a percentage.The methodology was tested on six real-world information systems with different architectures.The results demonstrated high consistency between the ARAS,CoCoSo,and TOPSISmethods,as well as the stability of the final rating when the criterion weights vary by±10%.The proposed approach provides a reproducible,transparent,and objective assessment of information system reliability and can be used to identify system bottlenecks,make modernization decisions,and manage the quality of digital infrastructure.
基金supported by the National Natural Science Foundation of China(Grant No.41961134032).
文摘The probabilistic stability evolution analysis of reservoir bank slopes is a crucial aspect of risk assessment,with core challenges including the consideration of deformation mechanisms and accurate determination of mechanical parameters.In this study,a novel time-varying reliability analysis framework based on sequential Bayesian updating of mechanical parameters is proposed.The inverse parameters account for damage time-dependent behavior,incorporating water effect and a strain-driven softening-hardening process that depends on sliding states.The likelihood function is enhanced to simultaneously consider observation error,surrogate model prediction error,and model structural error,with the introduction of physical penalty.Exploration of the high-dimensional parameter space is achieved via the Hamiltonian Monte Carlo(HMC)method and the physics knowledge-based time-dependent deformation surrogate model.The time-varying reliability analysis of the slope is performed using the multi-grid method.Taking a reservoir bank slope as a case study,the sequential updating of 12 mechanical parameters is conducted based on deformation time series from 16 monitoring points,thereby validating the proposed framework.The results indicate that the proposed framework effectively captures the posterior distribution of mechanical parameters,with the case slope remaining in a critically stable state after overall sliding,showing a high failure probability.Introducing model structural error can reduce parameter compensation,and a reasonable sequential updating step size can improve inversion accuracy.
基金The researchers would like to thank the Deanship of Graduate Studies and Scientific Research at Qassim University for financial support(QU-APC-2025)。
文摘The evolution of cities into digitally managed environments requires computational systems that can operate in real time while supporting predictive and adaptive infrastructure management.Earlier approaches have often advanced one dimension—such as Internet of Things(IoT)-based data acquisition,Artificial Intelligence(AI)-driven analytics,or digital twin visualization—without fully integrating these strands into a single operational loop.As a result,many existing solutions encounter bottlenecks in responsiveness,interoperability,and scalability,while also leaving concerns about data privacy unresolved.This research introduces a hybrid AI–IoT–Digital Twin framework that combines continuous sensing,distributed intelligence,and simulation-based decision support.The design incorporates multi-source sensor data,lightweight edge inference through Convolutional Neural Networks(CNN)and Long ShortTerm Memory(LSTM)models,and federated learning enhanced with secure aggregation and differential privacy to maintain confidentiality.A digital twin layer extends these capabilities by simulating city assets such as traffic flows and water networks,generating what-if scenarios,and issuing actionable control signals.Complementary modules,including model compression and synchronization protocols,are embedded to ensure reliability in bandwidth-constrained and heterogeneous urban environments.The framework is validated in two urban domains:traffic management,where it adapts signal cycles based on real-time congestion patterns,and pipeline monitoring,where it anticipates leaks through pressure and vibration data.Experimental results show a 28%reduction in response time,a 35%decrease in maintenance costs,and a marked reduction in false positives relative to conventional baselines.The architecture also demonstrates stability across 50+edge devices under federated training and resilience to uneven node participation.The proposed system provides a scalable and privacy-aware foundation for predictive urban infrastructure management.By closing the loop between sensing,learning,and control,it reduces operator dependence,enhances resource efficiency,and supports transparent governance models for emerging smart cities.
文摘The stochastic boundary element method(SBEM)is developed in this paper for 3D problems with body forces and reliability analysis of engineering structures.The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables,considering the yield limit,rotation speeds and material density to be the fundamental stochastic variables.Through analyzing a numerical example and a turbo-disk of an aeroengine,the results show that the method developed is successful.
基金supported by the National Science and Technology Plan(Major Project of the Eleventh Five-Year Plan,Grant No.2006BAB04A13)
文摘In order to analyze the indispensability of the organization management chain of the South-to-North Water Diversion Project （SNWDP）, two basic forms （series connection state and mixed state of both series connection and parallel connection） of the organization management chain can be abstracted. The indispensability of each form has been studied and is described in this paper. Through analysis of the reliability of the two basic forms, reliability models of the organization management chain in the series connection state and the mixed state of both series connection and parallel connection have been set up.
文摘An integrated intelligent management is presented to help organizations manage many heterogeneous resources in their information system. A general architecture of management for information system reliability is proposed, and the architecture from two aspects, process model and hierarchical model, described. Data mining techniques are used in data analysis. A data analysis system applicable to real-time data analysis is developed by improved data mining on the critical processes. The framework of the integrated management for information system reliability based on real-time data mining is illustrated, and the development of integrated and intelligent management of information system discussed.
文摘On the basis of analyzing the reliability of the organization’ management chain of the large and medium- sized project in the construction period, the paper studies the factors influencing the reliability of the organi-zation management chain, which, corresponding to four elements of management chain – “Management Loop”, “Management Link”, “Management Chain”, and “Management Network”, can be summarized as project main body, interface management, connection sequence and management model. The paper then re-searches on the specific influencing factors from the above-mentioned four aspects.
文摘A stochastic boundary element method (SBEM) is developed for 3-Dproblems with body forces. The integral equations of SBEM are established by the approach of partial derivation with respect to stochastic variables, considering the strengthlimit, rotation speeds and material density to be the fundamental stochastic variables.The method developed is applied to analyzing the strength reliability of the turbo diskof an aero-engine.
文摘Risk precontrol management system of coal mines safety( RPMSCS) provides a set of preventive safety management strategy for high-risk coal industries, which has captured extensive attentions. Fundamentally,there are several membership systems with subsystems in the management system, and the subsystem reliability has an important influence on the management system performance. Through analyzing the structure characteristics of the management system,the phase type distribution was employed to analyze its subsystem reliability by considering repair process and three states including working,fail-abnormal,and fail-emergency states. The reliability indices of the subsystem were derived respectively,including the probabilities that the subsystem in three states,mean time to the first failure, mean time to first failemergency,mean working time to first fail-emergency,and mean maintenance time to the first fail-emergency, are derived respectively. The probabilities of the membership systems and the management system in three states were also derived. Some numerical examples were used to show the procedures. The result is important for better understanding the management system operation and improving its operational performance from the respect of system reliability.
文摘In order to take into account the uncertainties linked to the variables in the evaluation of the statistical properties of structural response, a reliability approach with probabilistic aspect was considered. This is called the Probabilistic Transformation Method (PTM). This method is readily applicable when the function between the input and the output of the system is explicit. However, the situation is much more involved when it is necessary to perform the evaluation of implicit function between the input and the output of the system through numerical models. In this work, we propose a technique that combines Finite Element Analysis (FEA) and Probabilistic Transformation Method (PTM) to evaluate the Probability Density Function (PDF) of response where the function between the input and the output of the system is implicit. This technique is based on the numerical simulations of the Finite Element Analysis (FEA) and the Probabilistic Transformation Method (PTM) using an interface between Finite Element software and Matlab. Some problems of structures are treated in order to prove the applicability of the proposed technique. Moreover, the obtained results are compared to those obtained by the reference method of Monte Carlo. A second aim of this work is to develop an algorithm of global optimization using the local method SQP, because of its effectiveness and its rapidity of convergence. For this reason, we have combined the method SQP with the Multi start method. This developed algorithm is tested on test functions comparing with other methods such as the method of Particle Swarm Optimization (PSO). In order to test the applicability of the proposed approach, a structure is optimized under reliability constraints.
文摘To achieve excellent production capability and maintain high security for nuclear power stations, equipment reliability is studied as a key issue. As the main branch, equipment reliability management is considered as an effective approach to make plant management strategy and organize routine work. Some achievements on research and application of equipment reliability management at Daya Bay Nuclear Power Station are introduced in this paper. By studying and implementing 1NPO （Institute of Nuclear Power Operations） AP-913 equipment reliability process, reliability-centered maintenance （RCM）, critical component management （CCM）, and many other similar methods, equipment reliability management system has been established at Daya Bay. And by continuous effort on improving application effect of these technologies, some innovation has also been made. Some innovative products, such as iSOM Intelligent Expert System, reliability and technique centered maintenance （RtCM）, predictive maintenance system （PdM）, and so on, have been developed. Based on these achievements, Daya Bay Nuclear Power Station has achieved excellent operation performance and won several prizes in WANO （World Association of Nuclear Operators） competition every year.
文摘Software reliability models describe the failure behavior of the software. The models are used to evaluate the software quantitatively. They assess the reliability of the software by predicting faults or failures for a software. Reliability is one of important quality attributes of the software in which software end user is more interested rather than the software developer. Hence, the performance of a software can be improved by incorporating important quality attributes like reliability, maintainability and availability of the software along with performance attributes like response time and throughput. The paper discusses about the role played by important software reliability models in analyzing the failure prediction of the software. It also explores the strong relationship that exists between quality attributes and performance attributes. With some illustrations highlighting the necessity of in-depth understanding of the link that exists between reliability and performance of the software. The derived knowledge helps in improving the performance of the software sustainably over a period of time and manage the software more effectively.
文摘In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facilitate this study. First, methods used for such studies and their results at global level were reviewed. Then Australian specific methods of study and findings were reviewed. More commonly, both globally and in Australia, simulations using long-term real data on selected climatic scenarios of global climatic models are projected for long-term future trends. The validity and certainty of predicted occurrences depend upon the closeness of real time data with scenarios to which they are projected. Even with these limitations, projections of already rising temperatures and declining rainfall on surface water and ground water availabilities show gradual decline in water availability leading to water stress both for human communities and ecosystems The role of human-induced emissions in hastening the degradation process has also been investigated. Conserving all available water, practising efficient water consumption and prudent water policies only can provide some relief from what is inevitable.
文摘With the rapid development of the social economy,the pace of urban-rural integration construction has been accelerating continuously.From the actual situation at this stage,it is necessary to maintain the sound relationship of coordination,interaction and mutual advance between the city and the village.In the process of building urban-rural integration,we should focus on strengthening the development of land management,so as to improve the rationality of land development and utilization,and maximize the value of land while protecting rural farmland resources.The author explores and analyzes the problems existing in the land management work in the urban-rural integration construction.An effective way is put forward to carry out land management work in urban and rural integration construction,which contributes to the improvement of the quality of land management work.
文摘The quantity of bio-laboratories and bio-factories in Uzbekistan increases every year.In 1970,there were only 4,in 1971,16,in 1985,710,in 1990,774,and in 2000,790.At present there
文摘Solid waste management has become the greatest public health problem facing many urban and semi-urban areas in Ghana. Great wealth can be generated from wastes if managed effectively but also has high probability of causing serious health and environmental problems if not effectively managed. The study sought to determine factors militating against domestic solid waste management in Hohoe, possible ways of curbing them and also to assess the methods of domestic solid waste management. This study used descriptive cross-sectional survey and structured questionnaire to obtain the required information from respondents. A total number of 403 respondents were recruited into the study. The data collected were entered and analyzed using Statistical Package for Social Sciences version 20. The relationships between socio-demographic characteristics of the respondents and their use or non-use of apt domestic solid waste disposal methods were examined using chi-square analysis. The study found that 44% of respondents disposed domestic waste into central skip over dustbins. Spilled over of skip over dustbin has caused 8% of respondents to practice open burning. 7% dumped on undeveloped building plots, 5% dumped elsewhere, and 3% dumped into the river course. About 78% of respondents reported that mobilization of cleanups was irregular. The result from the study also showed a statistical significant association between practice of domestic solid waste management and religion [χ<sup>2</sup> (2, 403) = 60.9484, p α = 5%]. About 96% of Christians practiced good methods of domestic solid waste management compared to 4% of Muslims. The findings painted a gloomy picture of poor domestic solid waste management practice among the respondents in the study communities.
文摘During the construction process of the construction project,the construction technology management work can improve the overall quality of the project construction.In the context of increasingly fierce competition in the construction market,construction enterprises should strengthen the management of construction technology,enhance their technical level and market competitiveness,and promote the development of the construction market[1].The paper mainly analyzes the optimization methods of build-Keywords:ing construction technology management.
基金supports of the National Natural Science Foundation of China(Nos.12032008,12102080)the Fundamental Research Funds for the Central Universities,China(No.DUT23RC(3)038)are much appreciated。
文摘Fatigue analysis of engine turbine blade is an essential issue.Due to various uncertainties during the manufacture and operation,the fatigue damage and life of turbine blade present randomness.In this study,the randomness of structural parameters,working condition and vibration environment are considered for fatigue life predication and reliability assessment.First,the lowcycle fatigue problem is modelled as stochastic static system with random parameters,while the high-cycle fatigue problem is considered as stochastic dynamic system under random excitations.Then,to deal with the two failure modes,the novel Direct Probability Integral Method(DPIM)is proposed,which is efficient and accurate for solving stochastic static and dynamic systems.The probability density functions of accumulated damage and fatigue life of turbine blade for low-cycle and high-cycle fatigue problems are achieved,respectively.Furthermore,the time–frequency hybrid method is advanced to enhance the computational efficiency for governing equation of system.Finally,the results of typical examples demonstrate high accuracy and efficiency of the proposed method by comparison with Monte Carlo simulation and other methods.It is indicated that the DPIM is a unified method for predication of random fatigue life for low-cycle and highcycle fatigue problems.The rotational speed,density,fatigue strength coefficient,and fatigue plasticity index have a high sensitivity to fatigue reliability of engine turbine blade.
