针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(S...针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(Soft Actor-Critic,SAC)算法。首先,为解决训练初期探索效率低的问题,提出一种基于引斥力模型的策略引导机制,通过目标位置信息引导机械臂运动,加速收敛过程;其次,基于长短期记忆网络对算法的策略网络和价值网络进行改进,有效利用历史信息,增强策略学习能力,提高算法的收敛速度和稳定性。仿真结果表明,所提出的算法在行星减速器中心轴装配任务中取得显著的效果,装配成功率高达99.4%,与普通SAC算法相比,平均最大接触力和力矩分别降低了68.8%和79.2%。在物理环境中装配成功率达95%以上,最大接触力和力矩分别小于10 N和1.5 N·m,验证了算法的有效性。展开更多
为提高现有三维建模方法的精度和效率,研究提出基于无人机倾斜摄影与改进样本一致性迭代算法(Sample Consensus with Iterative Algorithm,SAC-IA)算法的三维建模方法,通过结合无人机多视角高分辨率影像采集技术,和改进SAC-IA与迭代最...为提高现有三维建模方法的精度和效率,研究提出基于无人机倾斜摄影与改进样本一致性迭代算法(Sample Consensus with Iterative Algorithm,SAC-IA)算法的三维建模方法,通过结合无人机多视角高分辨率影像采集技术,和改进SAC-IA与迭代最近点算法协同优化点云配准过程,有效提升建筑物三维建模的精度与速度。研究方法在XX古建筑的数字修复实验中成功应用,准确恢复了建筑物的细节,包括屋顶雕花和外立面的裂缝修复,相比传统的地面激光扫描和摄影测量技术,点云配准误差减少了17%~39%。且建模效率较传统方法提高了45%。由此证明,研究方法在提高建筑三维建模精度的同时,也提升了数据采集和处理效率,为复杂建筑物和大规模场景的三维建模提供可靠且高效的解决方案。展开更多
Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution...Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.展开更多
This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained...This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained by saturation.Measurements are transmitted to nodes of a sensor network over unreliable wireless channels.We propose a linear coding mechanism,together with a distributed method for obtaining a state estimate at each node.These designs aim to minimize the state estimation error covariance.In addition,we derive a bound on this covariance,and accommodate the design parameters to minimize this bound.The resulting design depends on the packet loss probabilities of the wireless channels.This permits applying the proposed scheme to systems in which communications suffer from denial-of-service attacks,as such attacks typically affect those probabilities.Finally,we present a numerical example illustrating this application.展开更多
Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information ...Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information semantics.Nevertheless,this paper challenges the conventional JSCC paradigm and advocates for adopting separate source channel coding(SSCC)to enjoy a more underlying degree of freedom for optimization.We demonstrate that SSCC,after leveraging the strengths of the Large Language Model(LLM)for source coding and Error Correction Code Transformer(ECCT)complemented for channel coding,offers superior performance over JSCC.Our proposed framework also effectively highlights the compatibility challenges between Sem Com approaches and digital communication systems,particularly concerning the resource costs associated with the transmission of high-precision floating point numbers.Through comprehensive evaluations,we establish that assisted by LLM-based compression and ECCT-enhanced error correction,SSCC remains a viable and effective solution for modern communication systems.In other words,separate source channel coding is still what we need.展开更多
Background Broiler chickens are most vulnerable immediately after hatching due to their immature immune systems,making them susceptible to infectious diseases.The yolk plays an important role in early immune defence b...Background Broiler chickens are most vulnerable immediately after hatching due to their immature immune systems,making them susceptible to infectious diseases.The yolk plays an important role in early immune defence by showing relevant antioxidant and passive immunity capabilities during broiler embryonic development.The immunomodulatory effects of phytogenic compound carvacrol have been widely reported.After in ovo delivery in the amniotic fluid during embryonic development carvacrol is known to migrate to the yolk sac.However,it is unknown whether carvacrol in the yolk could enhance defence responsiveness in the yolk sac.Therefore,the aim of this study was to improve early immune function in chicken embryos,and it was hypothesized that in ovo delivery of carvacrol would result in immunomodulatory effects in the yolk sac,potentially improving post-hatch resilience.Methods On embryonic day(E)17.5,either a saline(control)or carvacrol solution was injected into the amniotic fluid.Yolk sac tissue samples were collected at E19.5,and transcriptomic analyses using RNA sequencing were performed,following functional enrichment analyses comparing the control(saline)and carvacrol-injected groups.Results The results showed that 268 genes were upregulated and 174 downregulated in the carvacrol group compared to the control(P<0.05;logFC<-0.5 or log FC>0.5).Functional analyses of these differentially expressed genes,using KEGG,REACTOME,and Gene Ontology databases,showed enrichment of several immune-related pathways.This included the pathways‘Antimicrobial peptides’(P=0.001)and‘Chemoattractant activity’(P=0.004),amongst others.Moreover,the‘NOD-like receptor signaling’pathway was enriched(P=0.002).Antimicrobial peptides are part of the innate immune defence and are amongst the molecules produced after the nucleotide oligomeriza-tion domain(NOD)-like receptor pathway activation.While these responses may be associated with an inflammatory reaction to an exogenous threat,they could also indicate that in ovo delivery of carvacrol could prepare the newly hatched chick against bacterial pathogens by potentially promoting antimicrobial peptide production through acti-vation of NOD-like receptor signaling in the yolk sac.Conclusion In conclusion,these findings suggest that in ovo delivery of carvacrol has the potential to enhance anti-pathogenic and pro-inflammatory responses in the yolk sac via upregulation of antimicrobial peptides,and NOD-like receptor pathways.展开更多
文摘针对工业装配任务,尤其是不规则轴孔工件装配中,基于学习的前期样本质量低、训练过程不稳定等问题,提出一种融合引斥力模型(Attraction-Repulsion Model,ARM)引导机制和长短期记忆网络(Long Short Term Memory,LSTM)的柔性演员-评论家(Soft Actor-Critic,SAC)算法。首先,为解决训练初期探索效率低的问题,提出一种基于引斥力模型的策略引导机制,通过目标位置信息引导机械臂运动,加速收敛过程;其次,基于长短期记忆网络对算法的策略网络和价值网络进行改进,有效利用历史信息,增强策略学习能力,提高算法的收敛速度和稳定性。仿真结果表明,所提出的算法在行星减速器中心轴装配任务中取得显著的效果,装配成功率高达99.4%,与普通SAC算法相比,平均最大接触力和力矩分别降低了68.8%和79.2%。在物理环境中装配成功率达95%以上,最大接触力和力矩分别小于10 N和1.5 N·m,验证了算法的有效性。
文摘为提高现有三维建模方法的精度和效率,研究提出基于无人机倾斜摄影与改进样本一致性迭代算法(Sample Consensus with Iterative Algorithm,SAC-IA)算法的三维建模方法,通过结合无人机多视角高分辨率影像采集技术,和改进SAC-IA与迭代最近点算法协同优化点云配准过程,有效提升建筑物三维建模的精度与速度。研究方法在XX古建筑的数字修复实验中成功应用,准确恢复了建筑物的细节,包括屋顶雕花和外立面的裂缝修复,相比传统的地面激光扫描和摄影测量技术,点云配准误差减少了17%~39%。且建模效率较传统方法提高了45%。由此证明,研究方法在提高建筑三维建模精度的同时,也提升了数据采集和处理效率,为复杂建筑物和大规模场景的三维建模提供可靠且高效的解决方案。
文摘Compact size,high brightness,and wide field of view(FOV)are key requirements for long-wave infrared imagers used in military surveillance or night navigation.However,to meet the imaging requirements of high resolution and wide FOV,infrared optical systems often adopt complex optical lens groups,which will increase the size and weight of the optical system.In this paper,a strategy based on wavefront coding(WFC)is proposed to design a compact wide-FOV infrared imager.A cubic phase mask is inserted into the pupil plane of the infrared imager to correct the aberration.The simulated results show that,the WFC infrared imager has good imaging quality in a wide FOV of±16°.In addition,the WFC infrared imager achieves compactness with its 40 mm×40 mm×40 mm size.A fast focal ratio of 1 combined with an entrance pupil diameter of 25 mm ensures brightness.This work is of significance for designing a compact wide-FOV infrared imager.
基金supported by the KGJ Basic Research Fund(JCKY2023110C080)the National Natural Science Foundation of China(62322306,62173057,62033006)+2 种基金Aviation Science Foundation Project(2022Z018063001)the Argentinean Agency for Scientific and Technological Promotion(PICT-2021-I-A-00730)the National Foreign Expert Individual Project(H20240983).
文摘This article investigates the distributed recursive filtering problem for discrete-time stochastic cyber–physical systems.A particular feature of our work is that we consider systems in which the state is constrained by saturation.Measurements are transmitted to nodes of a sensor network over unreliable wireless channels.We propose a linear coding mechanism,together with a distributed method for obtaining a state estimate at each node.These designs aim to minimize the state estimation error covariance.In addition,we derive a bound on this covariance,and accommodate the design parameters to minimize this bound.The resulting design depends on the packet loss probabilities of the wireless channels.This permits applying the proposed scheme to systems in which communications suffer from denial-of-service attacks,as such attacks typically affect those probabilities.Finally,we present a numerical example illustrating this application.
基金supported in part by the National Key Research and Development Program of China under Grant No.2024YFE0200600the Zhejiang Provincial Natural Science Foundation of China under Grant No.LR23F010005the Huawei Cooperation Project under Grant No.TC20240829036。
文摘Along with the proliferating research interest in semantic communication(Sem Com),joint source channel coding(JSCC)has dominated the attention due to the widely assumed existence in efficiently delivering information semantics.Nevertheless,this paper challenges the conventional JSCC paradigm and advocates for adopting separate source channel coding(SSCC)to enjoy a more underlying degree of freedom for optimization.We demonstrate that SSCC,after leveraging the strengths of the Large Language Model(LLM)for source coding and Error Correction Code Transformer(ECCT)complemented for channel coding,offers superior performance over JSCC.Our proposed framework also effectively highlights the compatibility challenges between Sem Com approaches and digital communication systems,particularly concerning the resource costs associated with the transmission of high-precision floating point numbers.Through comprehensive evaluations,we establish that assisted by LLM-based compression and ECCT-enhanced error correction,SSCC remains a viable and effective solution for modern communication systems.In other words,separate source channel coding is still what we need.
基金support by AgriFutures Australia’s Chicken Meat Program[grant number PRJ-011584]is gratefully acknowledged.
文摘Background Broiler chickens are most vulnerable immediately after hatching due to their immature immune systems,making them susceptible to infectious diseases.The yolk plays an important role in early immune defence by showing relevant antioxidant and passive immunity capabilities during broiler embryonic development.The immunomodulatory effects of phytogenic compound carvacrol have been widely reported.After in ovo delivery in the amniotic fluid during embryonic development carvacrol is known to migrate to the yolk sac.However,it is unknown whether carvacrol in the yolk could enhance defence responsiveness in the yolk sac.Therefore,the aim of this study was to improve early immune function in chicken embryos,and it was hypothesized that in ovo delivery of carvacrol would result in immunomodulatory effects in the yolk sac,potentially improving post-hatch resilience.Methods On embryonic day(E)17.5,either a saline(control)or carvacrol solution was injected into the amniotic fluid.Yolk sac tissue samples were collected at E19.5,and transcriptomic analyses using RNA sequencing were performed,following functional enrichment analyses comparing the control(saline)and carvacrol-injected groups.Results The results showed that 268 genes were upregulated and 174 downregulated in the carvacrol group compared to the control(P<0.05;logFC<-0.5 or log FC>0.5).Functional analyses of these differentially expressed genes,using KEGG,REACTOME,and Gene Ontology databases,showed enrichment of several immune-related pathways.This included the pathways‘Antimicrobial peptides’(P=0.001)and‘Chemoattractant activity’(P=0.004),amongst others.Moreover,the‘NOD-like receptor signaling’pathway was enriched(P=0.002).Antimicrobial peptides are part of the innate immune defence and are amongst the molecules produced after the nucleotide oligomeriza-tion domain(NOD)-like receptor pathway activation.While these responses may be associated with an inflammatory reaction to an exogenous threat,they could also indicate that in ovo delivery of carvacrol could prepare the newly hatched chick against bacterial pathogens by potentially promoting antimicrobial peptide production through acti-vation of NOD-like receptor signaling in the yolk sac.Conclusion In conclusion,these findings suggest that in ovo delivery of carvacrol has the potential to enhance anti-pathogenic and pro-inflammatory responses in the yolk sac via upregulation of antimicrobial peptides,and NOD-like receptor pathways.
