System-of-systems （SOS） engineering involves a com- plex process of refining high-level SoS requirements into more detailed systems requirements and assessing the extent to which the performances of to-be systems ma...System-of-systems （SOS） engineering involves a com- plex process of refining high-level SoS requirements into more detailed systems requirements and assessing the extent to which the performances of to-be systems may possibly satisfy SoS capa- bility objectives. The key issue is how to model such requirements to automate the process of analysis and assessment. This paper suggests a meta-model that defines both functional and non- functional features of SoS requirements for command and control, communication, computer, intelligence, surveillance reconnais- sance （C41SR） systems. A domain-specific modeling language is defined by extending unified modeling language （UML） con- structed of class and association with fuzzy theory in order to model the fuzzy concepts of performance requirements. An effi- ciency evaluation function is introduced, based on Bezier curves, to predict the effectiveness of systems. An algorithm is presented to transform domain models in fuzzy UML into a requirements ontology in description logic （DL） so that requirements verification can be automated with a popular DL reasoner such as Pellet.展开更多
In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the ...In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the TSE estimation is modeled as the estimation fusion of a fixed bias and a Gaussian random variable. To address the challenge of high computational load induced by the accurate numerical method, two efficient methods are proposed for real-time application, which are called the circle tangent ellipse method（CTEM） and the line tangent ellipse method（LTEM）,respectively. Compared with the accurate numerical method and the traditional scalar quantity summation method（SQSM）, the computational load and accuracy of these four methods are extensively analyzed. The theoretical and experimental results both show that the computing time of the LTEM is approximately equal to that of the SQSM, while it is only about 1/30 and 1/6 of that of the numerical method and the CTEM. Moreover, the estimation result of the LTEM is parallel with that of the numerical method, but is more accurate than those of the SQSM and the CTEM. It is illustrated that the LTEM is quite appropriate for real-time TSE estimation in RNP application.展开更多
Cardiovascular disease(CVD)is a major global health challenge,which causes significant illness and death worldwide.These include a range of conditions that affect the heart and blood vessels,including coro-nary artery...Cardiovascular disease(CVD)is a major global health challenge,which causes significant illness and death worldwide.These include a range of conditions that affect the heart and blood vessels,including coro-nary artery disease,stroke,peripheral artery disease,and heart failure.Despite advances in medicine and healthcare delivery,CVD continues to have a serious impact on individuals,families,and the healthcare system.This review begins by delineating the merits and demerits of commonly employed synthetic and natural materials for artificial blood vessels.It delves into various techniques commonly employed in the fabrication of artificial blood vessels,encompassing advanced textile technologies,electrospinning,ther-mally induced phase separation,and 3D printing.The review critically analyzes the attributes of different preparation methodologies alongside the latest advancements in research.The review also outlines the requisite performance requirements for artificial blood vessels,which encompass robust mechanical prop-erties,appropriate porosity,exceptional compatibility,and antibacterial attributes.It provides a succinct overview of ongoing effort s in vascular functionalization,particularly emphasizing thrombus mitigation,promotion of endothelialization,and enhancement of nitric oxide production.The review finally encap-sulates the primary challenges confronting vascular grafts and prospective avenues for future research.展开更多
A new integrity metric for navigation systems is proposed based on the measurement domain. Proba-hilistic optimization design offers tools for fault detection by considering the required navigation performance （RNP）...A new integrity metric for navigation systems is proposed based on the measurement domain. Proba-hilistic optimization design offers tools for fault detection by considering the required navigation performance （RNP） parameter and the uncertainty noise. The choice of the proper performance parameter provided the single-valued mapping with the missed detection probability estimates the probability of failure. The desirable characteristics of the residual sensitivity matrix are exploited to increase the efficiency for identifying erroneous observations. The algorithm can be used to support the performance specification and the efficient calculation of the integrity monitoring process. The simulation for non-precision approach （NPA） validates both the viability and the effectiveness of the proposed algorithm.展开更多
The integrated optimal design of mechanical and control system is discussed in terms of the performance requirement and configuration for the single arm flexible manipulator. By combination of dynamics of flexible str...The integrated optimal design of mechanical and control system is discussed in terms of the performance requirement and configuration for the single arm flexible manipulator. By combination of dynamics of flexible structure and control theory, a PD feedback control system, which minimizes the settling time, has been designed. Then, the viable region of poles of the PD dosed-loop control system is decided according to overshoot and the settling time, and an integrated optimal model of structure and control of single arm manipulator is presented. Finally, the parameters of structure and control system are simultaneously optimized with respect to objective function induding the moment of inertia and the control effort of system.展开更多
Maximum regulated takeoff weights and hence payloads of large commercial jets are limited by government regulations which take into account local airport conditions as well as a variety of safety factors. One of the c...Maximum regulated takeoff weights and hence payloads of large commercial jets are limited by government regulations which take into account local airport conditions as well as a variety of safety factors. One of the challenging conditions that must be met is linked to a minimum obstacle clearance in the unlikely event of an engine failure on the runway at the worst possible time. This requirement becomes an overriding factor for airports surrounded by challenging terrain, and therefore a well defined takeoff path out of these airports has the potential to transform a financially unsustainable operation into a commercially viable one. The research described in this paper represents an ongoing attempt to resolve this important problem and makes use of recent advances in robot path planning techniques.展开更多
This paper discusses the application of Integrated Design Process for the design of low-cost housing in Chile.It aims to question common practice for the development of housing based on prescriptive regulations and no...This paper discusses the application of Integrated Design Process for the design of low-cost housing in Chile.It aims to question common practice for the development of housing based on prescriptive regulations and non-interdisciplinary work,which has resulted in poor quality building requirements.The first stage consisted in defining performance requirements for aspects such as energy demand,U value,air tightness and indoor air quality for a specific case of low-cost houses located in the city of Temuco.An integrated design process was carried out by an interdisciplinary team of professionals specialized in each of the performance aspects that were taken into account.The construction and post-occupancy stages were characterized by verifying the performance requirements,which resulted in a low-cost house prototype that included strategies for energy efficiency and a healthy indoor environment.展开更多
基金supported by the National Natural Science Foundation of China(61273210)
文摘System-of-systems （SOS） engineering involves a com- plex process of refining high-level SoS requirements into more detailed systems requirements and assessing the extent to which the performances of to-be systems may possibly satisfy SoS capa- bility objectives. The key issue is how to model such requirements to automate the process of analysis and assessment. This paper suggests a meta-model that defines both functional and non- functional features of SoS requirements for command and control, communication, computer, intelligence, surveillance reconnais- sance （C41SR） systems. A domain-specific modeling language is defined by extending unified modeling language （UML） con- structed of class and association with fuzzy theory in order to model the fuzzy concepts of performance requirements. An effi- ciency evaluation function is introduced, based on Bezier curves, to predict the effectiveness of systems. An algorithm is presented to transform domain models in fuzzy UML into a requirements ontology in description logic （DL） so that requirements verification can be automated with a popular DL reasoner such as Pellet.
基金supported by the National Basic Research Program of China (No. 2010CB731805)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 60921001)the Special Fund for Basic Research on Scientific Instruments of China (No. 2011YQ04008301)
文摘In required navigation performance（RNP）, total system error（TSE） is estimated to provide a timely warning in the presence of an excessive error. In this paper, by analyzing the underlying formation mechanism, the TSE estimation is modeled as the estimation fusion of a fixed bias and a Gaussian random variable. To address the challenge of high computational load induced by the accurate numerical method, two efficient methods are proposed for real-time application, which are called the circle tangent ellipse method（CTEM） and the line tangent ellipse method（LTEM）,respectively. Compared with the accurate numerical method and the traditional scalar quantity summation method（SQSM）, the computational load and accuracy of these four methods are extensively analyzed. The theoretical and experimental results both show that the computing time of the LTEM is approximately equal to that of the SQSM, while it is only about 1/30 and 1/6 of that of the numerical method and the CTEM. Moreover, the estimation result of the LTEM is parallel with that of the numerical method, but is more accurate than those of the SQSM and the CTEM. It is illustrated that the LTEM is quite appropriate for real-time TSE estimation in RNP application.
基金the National Natural Science Foundation of China(No.82374295)the National Key R&D Program of China(No.2021YFE0111100)+1 种基金the Science and Technol-ogy Partnership Program by the Ministry of Science and Technol-ogy of China(No.KY202201002)the Jiangsu Provincial De-partment of Science and Technology(No.BZ2022017).
文摘Cardiovascular disease(CVD)is a major global health challenge,which causes significant illness and death worldwide.These include a range of conditions that affect the heart and blood vessels,including coro-nary artery disease,stroke,peripheral artery disease,and heart failure.Despite advances in medicine and healthcare delivery,CVD continues to have a serious impact on individuals,families,and the healthcare system.This review begins by delineating the merits and demerits of commonly employed synthetic and natural materials for artificial blood vessels.It delves into various techniques commonly employed in the fabrication of artificial blood vessels,encompassing advanced textile technologies,electrospinning,ther-mally induced phase separation,and 3D printing.The review critically analyzes the attributes of different preparation methodologies alongside the latest advancements in research.The review also outlines the requisite performance requirements for artificial blood vessels,which encompass robust mechanical prop-erties,appropriate porosity,exceptional compatibility,and antibacterial attributes.It provides a succinct overview of ongoing effort s in vascular functionalization,particularly emphasizing thrombus mitigation,promotion of endothelialization,and enhancement of nitric oxide production.The review finally encap-sulates the primary challenges confronting vascular grafts and prospective avenues for future research.
基金Supported by the National High Technology Research and Development Program of China (‘863’Program) (2006AA12Z313)~~
文摘A new integrity metric for navigation systems is proposed based on the measurement domain. Proba-hilistic optimization design offers tools for fault detection by considering the required navigation performance （RNP） parameter and the uncertainty noise. The choice of the proper performance parameter provided the single-valued mapping with the missed detection probability estimates the probability of failure. The desirable characteristics of the residual sensitivity matrix are exploited to increase the efficiency for identifying erroneous observations. The algorithm can be used to support the performance specification and the efficient calculation of the integrity monitoring process. The simulation for non-precision approach （NPA） validates both the viability and the effectiveness of the proposed algorithm.
文摘The integrated optimal design of mechanical and control system is discussed in terms of the performance requirement and configuration for the single arm flexible manipulator. By combination of dynamics of flexible structure and control theory, a PD feedback control system, which minimizes the settling time, has been designed. Then, the viable region of poles of the PD dosed-loop control system is decided according to overshoot and the settling time, and an integrated optimal model of structure and control of single arm manipulator is presented. Finally, the parameters of structure and control system are simultaneously optimized with respect to objective function induding the moment of inertia and the control effort of system.
文摘Maximum regulated takeoff weights and hence payloads of large commercial jets are limited by government regulations which take into account local airport conditions as well as a variety of safety factors. One of the challenging conditions that must be met is linked to a minimum obstacle clearance in the unlikely event of an engine failure on the runway at the worst possible time. This requirement becomes an overriding factor for airports surrounded by challenging terrain, and therefore a well defined takeoff path out of these airports has the potential to transform a financially unsustainable operation into a commercially viable one. The research described in this paper represents an ongoing attempt to resolve this important problem and makes use of recent advances in robot path planning techniques.
基金the dissemination of this work have been supported by CONICYT project MEL 81100003.
文摘This paper discusses the application of Integrated Design Process for the design of low-cost housing in Chile.It aims to question common practice for the development of housing based on prescriptive regulations and non-interdisciplinary work,which has resulted in poor quality building requirements.The first stage consisted in defining performance requirements for aspects such as energy demand,U value,air tightness and indoor air quality for a specific case of low-cost houses located in the city of Temuco.An integrated design process was carried out by an interdisciplinary team of professionals specialized in each of the performance aspects that were taken into account.The construction and post-occupancy stages were characterized by verifying the performance requirements,which resulted in a low-cost house prototype that included strategies for energy efficiency and a healthy indoor environment.
