Disassembly sequence planning is an important step of mechanical maintenance. This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence. Mechanical products ar...Disassembly sequence planning is an important step of mechanical maintenance. This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence. Mechanical products are divided into two categories of components and connectors. The article uses component-joint graph to represent assembly constraints, including the incidence constraints are represented by incidence matrix and the interference constraints are represented by interference constraints. The inspiring factor and pheromone matrix are calculated according to assembly constraints. Then the ant generates its own disassembly sequences one by one and updates the inspiring factor and pheromone matrix. After all iterations, the best disassembly sequence planning of components and connectors are given. Finally, an application instance of the disassembly sequence of the jack is presented to illustrate the validity of this method.展开更多
In this paper, a new kind of simple-encoding irregular systematic LDPC codes suitable for one-relay coded cooperation is designed, where the proposed joint iterative decoding is effectively performed in the destinatio...In this paper, a new kind of simple-encoding irregular systematic LDPC codes suitable for one-relay coded cooperation is designed, where the proposed joint iterative decoding is effectively performed in the destination which is in accordance with the corresponding joint Tanner graph characterizing two different component LDPC codes used by the source and relay in ideal and non-ideal relay cooperations. The theoretical analysis and simulations show that the coded cooperation scheme obviously outperforms the coded non-cooperation one under the same code rate and decoding complex. The significant performance improvement can be virtually credited to the additional mutual exchange of the extrinsic information resulted by the LDPC code employed by the source and its counterpart used by the relay in both ideal and non-ideal cooperations.展开更多
A network-coding-based multisource LDPC-coded cooperative MIMO scheme is proposed,where multiple sources transmit their messages to the destination with the assistance from a single relay.The relay cooperates with mul...A network-coding-based multisource LDPC-coded cooperative MIMO scheme is proposed,where multiple sources transmit their messages to the destination with the assistance from a single relay.The relay cooperates with multiple sources simultaneously via network-coding.It avoids the issues of imperfect frequency/timing synchronization and large transmission delay which may be introduced by frequency-division multiple access(FDMA)/code-division multiple access(CDMA)and time-division multiple access(TDMA)manners.The proposed joint″Min-Sum″iterative decoding is effectively carried out in the destination.Such a decoding algorithm agrees with the introduced equivalent joint Tanner graph which can be used to fully characterize LDPC codes employed by the sources and relay.Theoretical analysis and numerical simulation show that the proposed scheme with joint iterative decoding can achieve significant cooperation diversity gain.Furthermore,for the relay,compared with the cascade scheme,the proposed scheme has much lower complexity of LDPC-encoding and is easier to be implemented in the hardware with similar bit error rate(BER)performance.展开更多
设备运维是保障生产正常进行的重要基础,现有的智能运维技术主要依赖信号分析、数据挖掘或专家知识重用。然而,随着设备自动化和集成化程度的提高,其各类运行异常的表征信号、多源致因和维护方案之间的关系呈现出更高的模糊性和复杂性,...设备运维是保障生产正常进行的重要基础,现有的智能运维技术主要依赖信号分析、数据挖掘或专家知识重用。然而,随着设备自动化和集成化程度的提高,其各类运行异常的表征信号、多源致因和维护方案之间的关系呈现出更高的模糊性和复杂性,将信号、数据和知识进行融合分析是提高设备运维精度和效率的关键。为此,采用知识图谱技术将“人”、“机”、“物”三元数据融合来支撑复杂设备的异常诊断和维护方案决策,提高运维智能化程度、避免决策片面性。首先,对设备运维领域人机物三元数据进行定义并完成三元本体设计,指导知识图数据层的构建。其次,对人机物三元数据进行预处理并搭建了统一混合注意力机制联合抽取模型(Joint entity and relation extraction model with mixed attention,MAREL)从三元数据中自动抽取知识,并建立三元知识之间的关联关系,以此实现人机物三元数据的融合;MAREL模型将任务拆解为两个关联的解码模块来解决实体重叠问题,利用混合注意力机制增强模型的长文本处理能力,在中文数据集SKE上的测试证明MAREL具有优异的性能。最后,以某汽车生产机器人设备运维人机物知识图谱的构建为例,验证了所提方法的有效性,结果表明知识图谱能够将人机物三元数据有效融合,为工业设备的智能运维提供支持。展开更多
We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In thi...We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In this paper we investigate whether some well-known graphs are Tribonacci cordial.展开更多
文摘Disassembly sequence planning is an important step of mechanical maintenance. This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence. Mechanical products are divided into two categories of components and connectors. The article uses component-joint graph to represent assembly constraints, including the incidence constraints are represented by incidence matrix and the interference constraints are represented by interference constraints. The inspiring factor and pheromone matrix are calculated according to assembly constraints. Then the ant generates its own disassembly sequences one by one and updates the inspiring factor and pheromone matrix. After all iterations, the best disassembly sequence planning of components and connectors are given. Finally, an application instance of the disassembly sequence of the jack is presented to illustrate the validity of this method.
基金Supported by the Open Research Fund of National Moblie Communications Research Laboratory of Southeast Uni-versity (No. W200704)
文摘In this paper, a new kind of simple-encoding irregular systematic LDPC codes suitable for one-relay coded cooperation is designed, where the proposed joint iterative decoding is effectively performed in the destination which is in accordance with the corresponding joint Tanner graph characterizing two different component LDPC codes used by the source and relay in ideal and non-ideal relay cooperations. The theoretical analysis and simulations show that the coded cooperation scheme obviously outperforms the coded non-cooperation one under the same code rate and decoding complex. The significant performance improvement can be virtually credited to the additional mutual exchange of the extrinsic information resulted by the LDPC code employed by the source and its counterpart used by the relay in both ideal and non-ideal cooperations.
基金Supported by the Postdoctoral Science Foundation of China(2014M561694)the Science and Technology on Avionics Integration Laboratory and National Aeronautical Science Foundation of China(20105552)
文摘A network-coding-based multisource LDPC-coded cooperative MIMO scheme is proposed,where multiple sources transmit their messages to the destination with the assistance from a single relay.The relay cooperates with multiple sources simultaneously via network-coding.It avoids the issues of imperfect frequency/timing synchronization and large transmission delay which may be introduced by frequency-division multiple access(FDMA)/code-division multiple access(CDMA)and time-division multiple access(TDMA)manners.The proposed joint″Min-Sum″iterative decoding is effectively carried out in the destination.Such a decoding algorithm agrees with the introduced equivalent joint Tanner graph which can be used to fully characterize LDPC codes employed by the sources and relay.Theoretical analysis and numerical simulation show that the proposed scheme with joint iterative decoding can achieve significant cooperation diversity gain.Furthermore,for the relay,compared with the cascade scheme,the proposed scheme has much lower complexity of LDPC-encoding and is easier to be implemented in the hardware with similar bit error rate(BER)performance.
文摘设备运维是保障生产正常进行的重要基础,现有的智能运维技术主要依赖信号分析、数据挖掘或专家知识重用。然而,随着设备自动化和集成化程度的提高,其各类运行异常的表征信号、多源致因和维护方案之间的关系呈现出更高的模糊性和复杂性,将信号、数据和知识进行融合分析是提高设备运维精度和效率的关键。为此,采用知识图谱技术将“人”、“机”、“物”三元数据融合来支撑复杂设备的异常诊断和维护方案决策,提高运维智能化程度、避免决策片面性。首先,对设备运维领域人机物三元数据进行定义并完成三元本体设计,指导知识图数据层的构建。其次,对人机物三元数据进行预处理并搭建了统一混合注意力机制联合抽取模型(Joint entity and relation extraction model with mixed attention,MAREL)从三元数据中自动抽取知识,并建立三元知识之间的关联关系,以此实现人机物三元数据的融合;MAREL模型将任务拆解为两个关联的解码模块来解决实体重叠问题,利用混合注意力机制增强模型的长文本处理能力,在中文数据集SKE上的测试证明MAREL具有优异的性能。最后,以某汽车生产机器人设备运维人机物知识图谱的构建为例,验证了所提方法的有效性,结果表明知识图谱能够将人机物三元数据有效融合,为工业设备的智能运维提供支持。
文摘We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In this paper we investigate whether some well-known graphs are Tribonacci cordial.
