In order to achieve quick and accurate lifetime prediction of LED lighting products under the testing time of 2 000 h, a method of online testing of luminous flux is proposed under the condition of temperature stress....In order to achieve quick and accurate lifetime prediction of LED lighting products under the testing time of 2 000 h, a method of online testing of luminous flux is proposed under the condition of temperature stress.Exponential fitting of lumen maintenance, the Bayesian estimation of failure probability, the Weibull distribution of lifetime and the Arrhenius model of the decay rate are used in combination to acquire the distribution of failure probability over time at the ambient temperatures of 25 ℃. The lifetime test of the same lamps based on the Energy Star standard under the testing time of 6 000 h is also implemented to verify the effectiveness of the method. The errors of lifetimes acquired with the proposed method are 7%, 4%, 3% and 1% at the failure probabilities of 62. 3%, 10%, 5% and 1%,respectively.展开更多
This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested su...This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force. Due to their robustness and portability, individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories. Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages. To conduct a substructure online hybrid test, an extensible framework is developed, which is equipped with a generalized interface to encapsulate each substructure. Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework, simply interfaced with the boundary displacements and forces. A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated. An Interuet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments. A series of online hybrid tests are introduced, and the portability, flexibility, and extensibility of the online hybrid test system are demonstrated.展开更多
THE name Zhen Huan has once again become a household name across China, On August 18, 2017, the author of the popular novel featuring Zhen's life in the imperial court in the Qing Dynasty (1644-1911), now also a hi...THE name Zhen Huan has once again become a household name across China, On August 18, 2017, the author of the popular novel featuring Zhen's life in the imperial court in the Qing Dynasty (1644-1911), now also a hit TV series, filed the first case tried by the first online court, Hangzhou Court of the Internet, in China - and the world,展开更多
We propose an approach to detect the temporary faults induced by an environmental phenomenon called single event upset(SEU). Berger code based self-checking checkers provides an online detection of faults in digital c...We propose an approach to detect the temporary faults induced by an environmental phenomenon called single event upset(SEU). Berger code based self-checking checkers provides an online detection of faults in digital circuits as well as in memory arrays. In this work, a concurrent Berger code based online self-testable architecture is proposed and integrated in 32-bit DLX reduced instruction set computer(RISC) processor on a single silicon chip. The proposed concurrent test methodology is implemented and verified for various arithmetic and logical operations of the DLX processor. The FPGA implementation of the proposed design shows that a meager increase in hardware utilization facilitates online self-testing to detect temporary faults.展开更多
Online testing is critical to ensuring reliable operations of the next generation of supercomputers based on a kilo-core network-on-chip(NoC)interconnection fabric.We present a parallel software-based self-testing(SBS...Online testing is critical to ensuring reliable operations of the next generation of supercomputers based on a kilo-core network-on-chip(NoC)interconnection fabric.We present a parallel software-based self-testing(SBST)solution that makes use of the bounded model checking(BMC)technique to generate test sequences and parallel packets.In this method,the parallel SBST with BMC derives the leading sequence for each router’s internal function and detects all functionally-testable faults related to the function.A Monte-Carlo simulation algorithm is then used to search for the approximately optimum configuration of the parallel packets,which guarantees the test quality and minimizes the test cost.Finally,a multi-threading technology is used to ensure that the Monte-Carlo simulation can reach the approximately optimum configuration in a large random space and reduce the generating time of the parallel test.Experimental results show that the proposed method achieves a high fault coverage with a reduced test overhead.Moreover,by performing online testing in the functional mode with SBST,it effectively avoids the over-testing problem caused by functionally untestable turns in kilo-core NoCs.展开更多
A new online hybrid test system combined with substructuring techniques and incorporating finite element methods is developed.In the proposed system,numerical substructure analysis is conducted by ABAQUS/Explicit.An A...A new online hybrid test system combined with substructuring techniques and incorporating finite element methods is developed.In the proposed system,numerical substructure analysis is conducted by ABAQUS/Explicit.An ABAQUS user subroutine is used as the interface between the main control program and ABAQUS to impose the target displacements and determine the reaction forces.No iteration is needed in this system,making it suitable for physical testing.As the approach also avoids the need to modify source code,it will be appealing to a number of real engineering applications.The proposed system adopts a separated-model framework,operator-splitting integration scheme,and data exchange through a socket mechanism.The earthquake responses of a simple steel moment-resisting frame are simulated,and the results obtained from the new system are compared to those obtained from the conventional analysis.It is found that the results obtained from the new system are accurate,demonstrating the applicability and efficiency of the proposed approach.The optimal test parameters are also studied to gain the most accurate results in the minimum time.展开更多
基金The Cui Can Project of Chinese Academy of Sciences(No.KZCC-EW-102)the National High Technology Research and Development Program of China(863 Program)(No.2015AA03A101,2013AA03A116)
文摘In order to achieve quick and accurate lifetime prediction of LED lighting products under the testing time of 2 000 h, a method of online testing of luminous flux is proposed under the condition of temperature stress.Exponential fitting of lumen maintenance, the Bayesian estimation of failure probability, the Weibull distribution of lifetime and the Arrhenius model of the decay rate are used in combination to acquire the distribution of failure probability over time at the ambient temperatures of 25 ℃. The lifetime test of the same lamps based on the Energy Star standard under the testing time of 6 000 h is also implemented to verify the effectiveness of the method. The errors of lifetimes acquired with the proposed method are 7%, 4%, 3% and 1% at the failure probabilities of 62. 3%, 10%, 5% and 1%,respectively.
基金Public Benefit Research Foundation under Grant No.201108006Natural Science Foundation under Grant No.51161120360+2 种基金Heilongjiang Overseas Funding under Grant No.LC201002 of ChinaGrant-in-Aid for Scientific Research(Basic Research Category A,19206060)Japan Society for the Promotion of Science
文摘This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force. Due to their robustness and portability, individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories. Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages. To conduct a substructure online hybrid test, an extensible framework is developed, which is equipped with a generalized interface to encapsulate each substructure. Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework, simply interfaced with the boundary displacements and forces. A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated. An Interuet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments. A series of online hybrid tests are introduced, and the portability, flexibility, and extensibility of the online hybrid test system are demonstrated.
文摘THE name Zhen Huan has once again become a household name across China, On August 18, 2017, the author of the popular novel featuring Zhen's life in the imperial court in the Qing Dynasty (1644-1911), now also a hit TV series, filed the first case tried by the first online court, Hangzhou Court of the Internet, in China - and the world,
文摘We propose an approach to detect the temporary faults induced by an environmental phenomenon called single event upset(SEU). Berger code based self-checking checkers provides an online detection of faults in digital circuits as well as in memory arrays. In this work, a concurrent Berger code based online self-testable architecture is proposed and integrated in 32-bit DLX reduced instruction set computer(RISC) processor on a single silicon chip. The proposed concurrent test methodology is implemented and verified for various arithmetic and logical operations of the DLX processor. The FPGA implementation of the proposed design shows that a meager increase in hardware utilization facilitates online self-testing to detect temporary faults.
基金supported in part by the National Key Research and Development Program of China under Grant No.2020YFB1600201the National Natural Science Foundation of China(NSFC)under Grant Nos.61974105,62090024,U20A20202the Zhejiang Lab under Grant No.2021KC0AB01.
文摘Online testing is critical to ensuring reliable operations of the next generation of supercomputers based on a kilo-core network-on-chip(NoC)interconnection fabric.We present a parallel software-based self-testing(SBST)solution that makes use of the bounded model checking(BMC)technique to generate test sequences and parallel packets.In this method,the parallel SBST with BMC derives the leading sequence for each router’s internal function and detects all functionally-testable faults related to the function.A Monte-Carlo simulation algorithm is then used to search for the approximately optimum configuration of the parallel packets,which guarantees the test quality and minimizes the test cost.Finally,a multi-threading technology is used to ensure that the Monte-Carlo simulation can reach the approximately optimum configuration in a large random space and reduce the generating time of the parallel test.Experimental results show that the proposed method achieves a high fault coverage with a reduced test overhead.Moreover,by performing online testing in the functional mode with SBST,it effectively avoids the over-testing problem caused by functionally untestable turns in kilo-core NoCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.91315301 and 51422809)Tsinghua University Initiative Scientific Research Program(Grant No.2010Z01001)
文摘A new online hybrid test system combined with substructuring techniques and incorporating finite element methods is developed.In the proposed system,numerical substructure analysis is conducted by ABAQUS/Explicit.An ABAQUS user subroutine is used as the interface between the main control program and ABAQUS to impose the target displacements and determine the reaction forces.No iteration is needed in this system,making it suitable for physical testing.As the approach also avoids the need to modify source code,it will be appealing to a number of real engineering applications.The proposed system adopts a separated-model framework,operator-splitting integration scheme,and data exchange through a socket mechanism.The earthquake responses of a simple steel moment-resisting frame are simulated,and the results obtained from the new system are compared to those obtained from the conventional analysis.It is found that the results obtained from the new system are accurate,demonstrating the applicability and efficiency of the proposed approach.The optimal test parameters are also studied to gain the most accurate results in the minimum time.