After analysing and discussing the goal and problems of computer networkdesign, the authors developed a computer network CAD with detaileddescriptions. Its architecture, functions and modules are given. Lastly a set o...After analysing and discussing the goal and problems of computer networkdesign, the authors developed a computer network CAD with detaileddescriptions. Its architecture, functions and modules are given. Lastly a set ofparameters for performance evaluation are proposed.展开更多
The varied network performance in the cloud hurts application performance.This increases the tenant’s cost and becomes the key hindrance to cloud adoption.It is because virtual machines(VMs)belonging to one tenant ca...The varied network performance in the cloud hurts application performance.This increases the tenant’s cost and becomes the key hindrance to cloud adoption.It is because virtual machines(VMs)belonging to one tenant can reside in multiple physical servers and communication interference across tenants occasionally occurs when encountering network congestion.In order to prevent such unpredictability,it is critical for cloud providers to offer the guaranteed network performance at tenant level.Such a critical issue has drawn increasing attention in both academia and industry.Many elaborate mechanisms are proposed to provide guaranteed network performance,such as guaranteed bandwidth or bounded message delay across tenants.However,due to the intrinsic complexities and limited capabilities of commodity hardware,the deployment of these mechanisms still faces great challenges in current cloud datacenters.Moreover,with the rapid development of new technologies,there are new opportunities to improve the performance of existing works,but these possibilities are not under full discussion yet.Therefore,in this paper,we survey the latest development of the network performance guarantee approaches and summarize them based on their features.Then,we explore and discuss the possibilities of using emerging technologies as knobs to upgrade the performance or overcome the inherent shortcomings of existing advances.We hope this article will help readers quickly Received:Apr.07,2020 Revised:Oct.23,2020 Editor:Haifeng Zheng understand the causes of the problems and serve as a guide to motivate researchers to develop innovative algorithms and frameworks.展开更多
The Wireless Sensor Network (WSN) is spatially distributed autonomous sensor to sense special task. WSN like ZigBee network forms simple interconnecting, low power, and low processing capability wireless devices. The ...The Wireless Sensor Network (WSN) is spatially distributed autonomous sensor to sense special task. WSN like ZigBee network forms simple interconnecting, low power, and low processing capability wireless devices. The ZigBee devices facilitate numerous applications such as pervasive computing, security monitoring and control. ZigBee end devices collect sensing data and send them to ZigBee Coordinator. The Coordinator processes end device requests. The effect of a large number of random unsynchronized requests may degrade the overall network performance. An effective technique is particularly needed for synchronizing available node’s request processing to design a reliable ZigBee network. In this paper, region based priority mechanism is implemented to synchronize request with Tree Routing Method. Riverbed is used to simulate and analyze overall ZigBee network performance. The results show that the performance of the overall priority based ZigBee network model is better than without a priority based model. This research paves the way for further designing and modeling a large scale ZigBee network.展开更多
We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share met...We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share methods of graphics file are also discussed. Release and dynamic management are accomplished with the B/S combined with C/S as well as the file organization based on attribute information, which have essential practical sense to the establishment of CAD NGL, share and cooperation in tech-design as well as the distance education of engineering graphics.展开更多
In order to improve competitive ability of market, mo torcycle enterprises, special the small and middle sized ones must use IT to org anize social resource and adopt effective production mode, namely the dispersed ne...In order to improve competitive ability of market, mo torcycle enterprises, special the small and middle sized ones must use IT to org anize social resource and adopt effective production mode, namely the dispersed networked design and manufacturing (DNDM), which was put forward and proved to b e one of vitality production modes in recent years. In responding to the new pro duction mode of VMCE, a dispersed networked CAD/CAM system (DNCADMS) of motorcyc le products should be developed. The objective of this paper is to investigate a new design and manufacturing mode and technical environment of motorcycle produ ction based on the concept of the DNDM for the small and meddle sized motorcycle enterprises. Because there are various CAx software systems, including differen t kinds of isolated CD, CAD, CAE, CAPP, CAM, PDM, and so on, are used at differe nt stages of the life period of motorcycle products under heterogeneous environm ents, to build a DNCADMS of motorcycle with high performance, some key issues, n amely the architecture of the DNCADMS, the integration of the isolated CAx softw are systems (CAxs), the data communication and exchange between these isolated s ystems and the data share problem under the dispersed heterogeneous database env ironment, should be solved well. For this, the idea we propose is the combinatio n of Web, CORBA, STEP and Java, which provides an effective mechanism to support the integration of isolated CAxs, and support communication and interoperabilit y among CAx systems. Each isolated CAx has been encapsulated respectively by a c ontainer, which is implemented by the ORBs and the IDL of the COBRA technology s tandard, and managed by the application index server. Each container is connecte d with the others by a local network or intranet/Extranet/internet and communica tes through network. For exchanging design and manufacturing information and kno wledge via a local network or the Internet, a commmerical product data translato r has been employed as a product data translating server to complete product dat a communication and exchange between the isolated CAx systems. And for solving t he data share problem under the dispersed networked heterogeneous database envir onment, the idea we propose is to build a meta-database for the native database s, which is a dispersed database, and links various native databases into a whol e logical database. For managing the meta-database, the database index server, a Java-based integrating mechanism, has been also put forward in this paper. Th e application and database index servers have been implemented with Java lan guage. Moreover, the native data base and knowledge base related to each isolate d CAx are be integrated into a dispersed database system by a meta-base.展开更多
A system designed for supporting the network performance analysis and forecast effort is presented, based on the combination of offline network analysis and online real-time performance forecast. The off-line analysis...A system designed for supporting the network performance analysis and forecast effort is presented, based on the combination of offline network analysis and online real-time performance forecast. The off-line analysis will perform analysis of specific network node performance, correlation analysis of relative network nodes performance and evolutionary mathematical modeling of long-term network performance measurements. The online real-time network performance forecast will be based on one so-called hybrid prediction modeling approach for short-term network, performance prediction and trend analysis. Based on the module design, the system proposed has good intelligence, scalability and self-adaptability, which will offer highly effective network performance analysis and forecast tools for network managers, and is one ideal support platform for network performance analysis and forecast effort.展开更多
Emulation platforms are critical for evaluation and verification in the research of networking technologies and protocols for space networks(SN).High fidelity emulating technologies have been extensively studied for S...Emulation platforms are critical for evaluation and verification in the research of networking technologies and protocols for space networks(SN).High fidelity emulating technologies have been extensively studied for SN in earlier work,while little emphasis has been placed on the performance evaluation part.In this paper,the design of a network performance analysis architecture is presented,with which high-speed network traffic can be captured and indexed,and the performance of the emulated SN can be well analyzed and evaluated.This architecture comprises three components,namely capture layer,storage layer and analysis layer.Analytic Hierarchy Process(AHP)and several analysis methods are adopted to evaluate the network performance comprehensively.In the implementation of the proposed architecture,configuration optimization and parallel processing are applied to handle large amount of high-speed network traffic.Finally,experiment results through the analysis system exhibits the effectiveness of the proposed architecture.展开更多
Broadband provides high speed data transmission to Internet and 4G networks were developed to transform broadband technology with higher data rate and enhanced quality of service. The performance of broadband network ...Broadband provides high speed data transmission to Internet and 4G networks were developed to transform broadband technology with higher data rate and enhanced quality of service. The performance of broadband network in Nigeria in terms of type, purpose and speed was evaluated in this work. Some quarters at Ilesa and Oba-Ile in Akure were chosen as rural areas, while Abuja and Lagos represented the urban areas of the study. Questionnaires were administered among users in these areas randomly. Thereafter, data were analyzed and research questions answered from the analyzed results. The results showed that the majority of the respondents operated on wireless broadband technologies. The download speed is generally above 100 mbps in urban areas and below in rural areas, with MTN having the highest number of subscribers. In addition, most of the Internet surfers download files. With these characteristics, it was discovered that the network operators were deploying 3G systems as broadband instead of 4G systems.展开更多
Aeroengines,often regarded as the heart of aircraft,are crucial for flight safety and performance.Comprehensive performance evaluation of aeroengines supports Prognostics and Health Management(PHM)and aeroengine digit...Aeroengines,often regarded as the heart of aircraft,are crucial for flight safety and performance.Comprehensive performance evaluation of aeroengines supports Prognostics and Health Management(PHM)and aeroengine digital engineering.Due to their highly integrated nature,aeroengines present challenges in performance evaluation because their test-run data are high-dimensional,large-scale,and exhibit strong nonlinear correlations among test indicators.To solve this problem,this study proposes a unified framework of the comprehensive performance evaluation of aeroengines to assess performance objectively and globally.Specifically,the network model and the dynamics model of aeroengine performance are constructed driven by test-run data,which can explain the patterns of system state changes and the internal relationship,and depict the system accurately.Based on that,three perturbations in the model are used to simulate three fault modes of aeroengines.Moreover,the comprehensive performance evaluation indexes of aeroengines are proposed to evaluate the performance dynamically from two dimensions,the coupling performance and the activity performance.Thirteen test-run qualified and four test-run failed aeroengines are used to validate and establish the qualified ranges.The results demonstrate that the comprehensive evaluation indexes can distinguish test-run qualified and test-run failed aeroengines.By changing the dynamic parameters,the comprehensive performance under any thrust and inlet guide vanes(IGV)angle can be estimated,broadening the test-run scenarios beyond a few typical states.This novel approach offers significant advancements for the comprehensive performance evaluation and management of aeroengines,paving the way for future PHM and aeroengine digital engineering developments.展开更多
The social progress index(SPI)measures social and environmental performance beyond traditional economic indicators,providing transparent and actionable insights into the true condition of societies.This study investig...The social progress index(SPI)measures social and environmental performance beyond traditional economic indicators,providing transparent and actionable insights into the true condition of societies.This study investigates the interdependencies among SPI components and their impact on country-level sustainability performance.Using a Bayesian Belief Network(BBN)approach,the analysis explores the interdependencies among 12 SPI components(including advanced education,basic education,environmental quality,freedom and choice,health,housing,inclusive society,information and communications,nutrition and medical care,rights and voice,safety,and water and sanitation)and their collective influence on sustainability performance.Data from the Sustainable Development Report and SPI datasets,covering 162 countries(including Australia,China,United Arab Emirates,United Kingdom,United States,and so on),were used to assess the relative importance of each SPI component.The key findings indicate that advanced education,inclusive society,and freedom and choice make substantial contributions to high sustainability performance,whereas deficiencies in nutrition and medical care,water and sanitation,and freedom and choice are associated with poor sustainability performance.The results reveal that sustainability performance is shaped by a network of interlinked SPI components,with education and inclusion emerging as key levers for progress.The study emphasizes that targeted improvements in specific SPI components can significantly enhance a country’s overall sustainability performance.Rather than visualizing countries’progress through composite indicator-based heat maps,this study explores the interdependencies among SPI components and their role in sustainability performance at the global level.The study underscores the importance of a multidimensional policy approach that addresses social and environmental factors to enhance sustainability.The findings contribute to a deeper understanding of how SPI components interact and shape sustainable development.展开更多
The objective of tolerance analysis is to check the extent and nature of variation of an analyzed dimension or geometric feature of interest for a given GD & T scheme. The parametric approach to tolerance analysis...The objective of tolerance analysis is to check the extent and nature of variation of an analyzed dimension or geometric feature of interest for a given GD & T scheme. The parametric approach to tolerance analysis is based on parametric constraint solving. The accuracy of simulation results is dependent on the userdefined modeling scheme. Once an accurate CAD model is developed, it is integrated with tolerance synthesis model. In order to make it cost competent, it is necessary to obtain the costtolerance relationships. The neural network recently has been reported to be an effective statistical tool for determining relationship between input factors and output responses. This study deals development of direct constraint model in CAD, which is integrated to an optimal tolerance design problem. A backpropagation (BP) network is applied to fit the costtolerance relationship. An optimization method based on Differential Evolution (DE) is then used to locate the combination of controllable factors (tolerances) to optimize the output response (manufacturing cost plus quality loss) using the equations stemming from the trained network. A tolerance synthesis problem for a motor assembly is used to investigate the effectiveness and efficiency of the proposed methodology.展开更多
Social Networks Sites (SNSs) are dominating all internet users’ generations, especially the students’ communities. Consequently, academic institutions are increasingly using SNSs which leads to emerge a crucial ques...Social Networks Sites (SNSs) are dominating all internet users’ generations, especially the students’ communities. Consequently, academic institutions are increasingly using SNSs which leads to emerge a crucial question regarding the impact of SNSs on students’ academic performance. This research investigates how and to what degree the use of SNSs affects the students’ academic performance. The current research’s data was conducted by using drop and collect surveys on a large population from the University of Jordan. 366 undergraduate students answered the survey from different faculties at the university. In order to study the impact of SNSs on student’s academic performance, the research hypotheses was tested by using descriptive analysis, T-test and ANOVA. Research results showed that there was a significant impact of SNS on the student’s academic performance. Also, there was a significant impact of SNS use per week on the student’s academic performance, whereas no differences found in the impact of use of SNSs on academic performance due to age, academic achievement, and use per day to most used sites. The findings of this research can be used to suggest future strategies in enhancing student’s awareness in efficient time management and better multitasking that can lead to improving study activities and academic achievements.展开更多
The network on chip（NoC）is used as a solution for the communication problems in a complex system on chip（SoC）design.To further enhance performances,the NoC architectures,a high level modeling and an evaluation met...The network on chip（NoC）is used as a solution for the communication problems in a complex system on chip（SoC）design.To further enhance performances,the NoC architectures,a high level modeling and an evaluation method based on OPNET are proposed to analyze their performances on different injection rates and traffic patterns.Simulation results for general NoC in terms of the average latency and the throughput are analyzed and used as a guideline to make appropriate choices for a given application.Finally,a MPEG4 decoder is mapped on different NoC architectures.Results prove the effectiveness of the evaluation method.展开更多
An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power fallof...An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power falloff vs. distance. The 3G/ad hoc integrated network scenario model is introduced briefly. Based on this model, several performances of the 3G/ ad hoc integrated network in terms of outage probability, call dropping probability and new call blocking probability are evaluated. The corresponding performance formulae are deduced in accordance with the analytical models. Meanwhile, the formula of the 3G/ad hoc integrated network capacity is deduced on the basis of the formula of the outage probability. It is observed from extensive simulation and numerical analysis that the 3G/ad hoc integrated network remarkably outperforms the 3G network with regards to the network performance. This derived evaluation approach can be applied into planning and optimization of the 3G/ad hoc network.展开更多
文摘After analysing and discussing the goal and problems of computer networkdesign, the authors developed a computer network CAD with detaileddescriptions. Its architecture, functions and modules are given. Lastly a set ofparameters for performance evaluation are proposed.
基金This project is partially supported by the National Natural Science Foundation of China(No.61872401)Fok Ying Tung Education Foundation(No.171059).
文摘The varied network performance in the cloud hurts application performance.This increases the tenant’s cost and becomes the key hindrance to cloud adoption.It is because virtual machines(VMs)belonging to one tenant can reside in multiple physical servers and communication interference across tenants occasionally occurs when encountering network congestion.In order to prevent such unpredictability,it is critical for cloud providers to offer the guaranteed network performance at tenant level.Such a critical issue has drawn increasing attention in both academia and industry.Many elaborate mechanisms are proposed to provide guaranteed network performance,such as guaranteed bandwidth or bounded message delay across tenants.However,due to the intrinsic complexities and limited capabilities of commodity hardware,the deployment of these mechanisms still faces great challenges in current cloud datacenters.Moreover,with the rapid development of new technologies,there are new opportunities to improve the performance of existing works,but these possibilities are not under full discussion yet.Therefore,in this paper,we survey the latest development of the network performance guarantee approaches and summarize them based on their features.Then,we explore and discuss the possibilities of using emerging technologies as knobs to upgrade the performance or overcome the inherent shortcomings of existing advances.We hope this article will help readers quickly Received:Apr.07,2020 Revised:Oct.23,2020 Editor:Haifeng Zheng understand the causes of the problems and serve as a guide to motivate researchers to develop innovative algorithms and frameworks.
文摘The Wireless Sensor Network (WSN) is spatially distributed autonomous sensor to sense special task. WSN like ZigBee network forms simple interconnecting, low power, and low processing capability wireless devices. The ZigBee devices facilitate numerous applications such as pervasive computing, security monitoring and control. ZigBee end devices collect sensing data and send them to ZigBee Coordinator. The Coordinator processes end device requests. The effect of a large number of random unsynchronized requests may degrade the overall network performance. An effective technique is particularly needed for synchronizing available node’s request processing to design a reliable ZigBee network. In this paper, region based priority mechanism is implemented to synchronize request with Tree Routing Method. Riverbed is used to simulate and analyze overall ZigBee network performance. The results show that the performance of the overall priority based ZigBee network model is better than without a priority based model. This research paves the way for further designing and modeling a large scale ZigBee network.
文摘We aimed at the release and dynamic management of CAD network graphics library (NGL). The characteristics of realization on network of CAD graphics are analysed, while the existing problems of the presenting share methods of graphics file are also discussed. Release and dynamic management are accomplished with the B/S combined with C/S as well as the file organization based on attribute information, which have essential practical sense to the establishment of CAD NGL, share and cooperation in tech-design as well as the distance education of engineering graphics.
文摘In order to improve competitive ability of market, mo torcycle enterprises, special the small and middle sized ones must use IT to org anize social resource and adopt effective production mode, namely the dispersed networked design and manufacturing (DNDM), which was put forward and proved to b e one of vitality production modes in recent years. In responding to the new pro duction mode of VMCE, a dispersed networked CAD/CAM system (DNCADMS) of motorcyc le products should be developed. The objective of this paper is to investigate a new design and manufacturing mode and technical environment of motorcycle produ ction based on the concept of the DNDM for the small and meddle sized motorcycle enterprises. Because there are various CAx software systems, including differen t kinds of isolated CD, CAD, CAE, CAPP, CAM, PDM, and so on, are used at differe nt stages of the life period of motorcycle products under heterogeneous environm ents, to build a DNCADMS of motorcycle with high performance, some key issues, n amely the architecture of the DNCADMS, the integration of the isolated CAx softw are systems (CAxs), the data communication and exchange between these isolated s ystems and the data share problem under the dispersed heterogeneous database env ironment, should be solved well. For this, the idea we propose is the combinatio n of Web, CORBA, STEP and Java, which provides an effective mechanism to support the integration of isolated CAxs, and support communication and interoperabilit y among CAx systems. Each isolated CAx has been encapsulated respectively by a c ontainer, which is implemented by the ORBs and the IDL of the COBRA technology s tandard, and managed by the application index server. Each container is connecte d with the others by a local network or intranet/Extranet/internet and communica tes through network. For exchanging design and manufacturing information and kno wledge via a local network or the Internet, a commmerical product data translato r has been employed as a product data translating server to complete product dat a communication and exchange between the isolated CAx systems. And for solving t he data share problem under the dispersed networked heterogeneous database envir onment, the idea we propose is to build a meta-database for the native database s, which is a dispersed database, and links various native databases into a whol e logical database. For managing the meta-database, the database index server, a Java-based integrating mechanism, has been also put forward in this paper. Th e application and database index servers have been implemented with Java lan guage. Moreover, the native data base and knowledge base related to each isolate d CAx are be integrated into a dispersed database system by a meta-base.
基金the National 863 High-Tech Project (863 -3 0 0 -0 2 -0 9-99) and Key Research Project of Hubei Province(991P110 )
文摘A system designed for supporting the network performance analysis and forecast effort is presented, based on the combination of offline network analysis and online real-time performance forecast. The off-line analysis will perform analysis of specific network node performance, correlation analysis of relative network nodes performance and evolutionary mathematical modeling of long-term network performance measurements. The online real-time network performance forecast will be based on one so-called hybrid prediction modeling approach for short-term network, performance prediction and trend analysis. Based on the module design, the system proposed has good intelligence, scalability and self-adaptability, which will offer highly effective network performance analysis and forecast tools for network managers, and is one ideal support platform for network performance analysis and forecast effort.
基金supported by the National Natural Science Foundation of China under Grant 62131012the Fundamental Research Funds for the Central Universities under Grant 021014380187。
文摘Emulation platforms are critical for evaluation and verification in the research of networking technologies and protocols for space networks(SN).High fidelity emulating technologies have been extensively studied for SN in earlier work,while little emphasis has been placed on the performance evaluation part.In this paper,the design of a network performance analysis architecture is presented,with which high-speed network traffic can be captured and indexed,and the performance of the emulated SN can be well analyzed and evaluated.This architecture comprises three components,namely capture layer,storage layer and analysis layer.Analytic Hierarchy Process(AHP)and several analysis methods are adopted to evaluate the network performance comprehensively.In the implementation of the proposed architecture,configuration optimization and parallel processing are applied to handle large amount of high-speed network traffic.Finally,experiment results through the analysis system exhibits the effectiveness of the proposed architecture.
文摘Broadband provides high speed data transmission to Internet and 4G networks were developed to transform broadband technology with higher data rate and enhanced quality of service. The performance of broadband network in Nigeria in terms of type, purpose and speed was evaluated in this work. Some quarters at Ilesa and Oba-Ile in Akure were chosen as rural areas, while Abuja and Lagos represented the urban areas of the study. Questionnaires were administered among users in these areas randomly. Thereafter, data were analyzed and research questions answered from the analyzed results. The results showed that the majority of the respondents operated on wireless broadband technologies. The download speed is generally above 100 mbps in urban areas and below in rural areas, with MTN having the highest number of subscribers. In addition, most of the Internet surfers download files. With these characteristics, it was discovered that the network operators were deploying 3G systems as broadband instead of 4G systems.
基金supported by the National Natural Science Foundation of China(72231008,72171193,and 72071153)the Science and Technology Innovation Group Program of Shaanxi Province(2024RS-CXTD-28)the Open Fund of Intelligent Control Laboratory(ICL-2023-0304).
文摘Aeroengines,often regarded as the heart of aircraft,are crucial for flight safety and performance.Comprehensive performance evaluation of aeroengines supports Prognostics and Health Management(PHM)and aeroengine digital engineering.Due to their highly integrated nature,aeroengines present challenges in performance evaluation because their test-run data are high-dimensional,large-scale,and exhibit strong nonlinear correlations among test indicators.To solve this problem,this study proposes a unified framework of the comprehensive performance evaluation of aeroengines to assess performance objectively and globally.Specifically,the network model and the dynamics model of aeroengine performance are constructed driven by test-run data,which can explain the patterns of system state changes and the internal relationship,and depict the system accurately.Based on that,three perturbations in the model are used to simulate three fault modes of aeroengines.Moreover,the comprehensive performance evaluation indexes of aeroengines are proposed to evaluate the performance dynamically from two dimensions,the coupling performance and the activity performance.Thirteen test-run qualified and four test-run failed aeroengines are used to validate and establish the qualified ranges.The results demonstrate that the comprehensive evaluation indexes can distinguish test-run qualified and test-run failed aeroengines.By changing the dynamic parameters,the comprehensive performance under any thrust and inlet guide vanes(IGV)angle can be estimated,broadening the test-run scenarios beyond a few typical states.This novel approach offers significant advancements for the comprehensive performance evaluation and management of aeroengines,paving the way for future PHM and aeroengine digital engineering developments.
基金the resources and support provided by the American University of Sharjah to conduct this research
文摘The social progress index(SPI)measures social and environmental performance beyond traditional economic indicators,providing transparent and actionable insights into the true condition of societies.This study investigates the interdependencies among SPI components and their impact on country-level sustainability performance.Using a Bayesian Belief Network(BBN)approach,the analysis explores the interdependencies among 12 SPI components(including advanced education,basic education,environmental quality,freedom and choice,health,housing,inclusive society,information and communications,nutrition and medical care,rights and voice,safety,and water and sanitation)and their collective influence on sustainability performance.Data from the Sustainable Development Report and SPI datasets,covering 162 countries(including Australia,China,United Arab Emirates,United Kingdom,United States,and so on),were used to assess the relative importance of each SPI component.The key findings indicate that advanced education,inclusive society,and freedom and choice make substantial contributions to high sustainability performance,whereas deficiencies in nutrition and medical care,water and sanitation,and freedom and choice are associated with poor sustainability performance.The results reveal that sustainability performance is shaped by a network of interlinked SPI components,with education and inclusion emerging as key levers for progress.The study emphasizes that targeted improvements in specific SPI components can significantly enhance a country’s overall sustainability performance.Rather than visualizing countries’progress through composite indicator-based heat maps,this study explores the interdependencies among SPI components and their role in sustainability performance at the global level.The study underscores the importance of a multidimensional policy approach that addresses social and environmental factors to enhance sustainability.The findings contribute to a deeper understanding of how SPI components interact and shape sustainable development.
文摘The objective of tolerance analysis is to check the extent and nature of variation of an analyzed dimension or geometric feature of interest for a given GD & T scheme. The parametric approach to tolerance analysis is based on parametric constraint solving. The accuracy of simulation results is dependent on the userdefined modeling scheme. Once an accurate CAD model is developed, it is integrated with tolerance synthesis model. In order to make it cost competent, it is necessary to obtain the costtolerance relationships. The neural network recently has been reported to be an effective statistical tool for determining relationship between input factors and output responses. This study deals development of direct constraint model in CAD, which is integrated to an optimal tolerance design problem. A backpropagation (BP) network is applied to fit the costtolerance relationship. An optimization method based on Differential Evolution (DE) is then used to locate the combination of controllable factors (tolerances) to optimize the output response (manufacturing cost plus quality loss) using the equations stemming from the trained network. A tolerance synthesis problem for a motor assembly is used to investigate the effectiveness and efficiency of the proposed methodology.
文摘Social Networks Sites (SNSs) are dominating all internet users’ generations, especially the students’ communities. Consequently, academic institutions are increasingly using SNSs which leads to emerge a crucial question regarding the impact of SNSs on students’ academic performance. This research investigates how and to what degree the use of SNSs affects the students’ academic performance. The current research’s data was conducted by using drop and collect surveys on a large population from the University of Jordan. 366 undergraduate students answered the survey from different faculties at the university. In order to study the impact of SNSs on student’s academic performance, the research hypotheses was tested by using descriptive analysis, T-test and ANOVA. Research results showed that there was a significant impact of SNS on the student’s academic performance. Also, there was a significant impact of SNS use per week on the student’s academic performance, whereas no differences found in the impact of use of SNSs on academic performance due to age, academic achievement, and use per day to most used sites. The findings of this research can be used to suggest future strategies in enhancing student’s awareness in efficient time management and better multitasking that can lead to improving study activities and academic achievements.
基金Supported by the Natural Science Foundation of China(61076019)the China Postdoctoral Science Foundation(20100481134)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2008387)the Graduate Student Innovation Foundation of Jiangsu Province(CX07B-105z)~~
文摘The network on chip（NoC）is used as a solution for the communication problems in a complex system on chip（SoC）design.To further enhance performances,the NoC architectures,a high level modeling and an evaluation method based on OPNET are proposed to analyze their performances on different injection rates and traffic patterns.Simulation results for general NoC in terms of the average latency and the throughput are analyzed and used as a guideline to make appropriate choices for a given application.Finally,a MPEG4 decoder is mapped on different NoC architectures.Results prove the effectiveness of the evaluation method.
基金The National Natural Science Foundation of China(No.60872004)the Research Fund of National Mobile Communications Research Laboratory of Southeast University(No.2010A08)the Fundamental Research Funds for the Central Universities(No.2009B21814)
文摘An analytical approach to evaluate the performance of the 3G/ad hoc integrated network is presented. A channel model capturing both path loss and shadowing is applied to the analysis so as to characterize power falloff vs. distance. The 3G/ad hoc integrated network scenario model is introduced briefly. Based on this model, several performances of the 3G/ ad hoc integrated network in terms of outage probability, call dropping probability and new call blocking probability are evaluated. The corresponding performance formulae are deduced in accordance with the analytical models. Meanwhile, the formula of the 3G/ad hoc integrated network capacity is deduced on the basis of the formula of the outage probability. It is observed from extensive simulation and numerical analysis that the 3G/ad hoc integrated network remarkably outperforms the 3G network with regards to the network performance. This derived evaluation approach can be applied into planning and optimization of the 3G/ad hoc network.
