注塑件缺陷诊断专家系统的研究及应用

本文建立了一个基于知识的注塑件缺陷诊断专家系统ＫＢＤＤＥＳ。该系统采用不精确推理及确定性理论,按人类专家处理问题的思维方式来协调各专家对问题假设的不确定性,并运用正反向混合推理的控制策略,对常见的注塑件缺陷及注射过程中的故障进行诊断,得出结论并给出避免缺陷或故障的方法及建议。系统知识的表达采用了“框架十规则”的复合表达技术,使不同层次的知识源统一于同一知识表达结构内。     

Fully distributed consensus for fuzzy multiagent systems with jointly connected topology

This paper investigates the problem of fully distributed consensus for polynomial fuzzy multiagent systems (MASs) under jointly connected topologies. First, a polynomial fuzzy modeling method is presented to characterize the error dynamics that is constructed by one leader and multiple followers. Then, using the relative state information and the agents' dynamics, a distributed adaptive protocol is designed to guarantee that MASs under jointly connected topologies can achieve consensus in a fully distributed fashion. Utilizing the Lyapunov technique, a relaxed sufficient criterion is proposed to ensure consensus for fuzzy MASs under jointly connected topologies. Moreover, the adaptive coupling weights between neighboring agents can converge to certain values. The derived condition is transformed into a sum-of-squares form, which can be solved numerically. We provide an example to illustrate the proposed distributed adaptive consensus technique's validity.     

Quasi-min-max MPC for visual servoing stabilization of omnidirectional wheeled mobile robots

This paper proposes a new visual servoing quasi-min-max MPC algorithm for stabilization control of an omnidirectional wheeled mobile robot subject to physical and visual constraints. The visual servoing dynamics of the robot are modeled as the state-dependent linear error system with nonlinear control inputs of rotation and deflection velocities of wheels. The state-dependent linear error system is covered as linear parameters-varying models which is used to design the visual servoing quasi-min-max MPC controller. The actual control inputs of the robot are then computed by the solution of an inverse algebraic equation of the MPC actions. The recursive feasibility and stability of the new visual servoing MPC are ensured by some LMIs conditions. The performance and practicability of the visual servoing MPC are verified by some simulation and experiment results.     

Stabilization of uncertain networked control systems with actuator saturation and probabilistic cyberattacks

This paper investigates the stabilization of uncertain networked control systems (NCSs) with actuator saturation and cyberattacks. The cyberattacks are governed by a set of independent random variables satisfying Bernoulli distribution. To relieve the network bandwidth load effectively, an event-triggered communication strategy is proposed. By employing Lyapunov stability theory and stochastic analysis techniques, a stability criterion is obtained for the system with actuator saturation and cyberattacks. Moreover, the desired controller gain is derived by solving some matrix inequalities. Finally, the validity and applicability of the criteria are verified through numerical examples.     

Adaptive Clustered Federated Learning for Heterogeneous Data in Edge Computing

Mobile Networks and Applications - Although federated learning has been widely used in collaborative training of machine learning models, its practical uses are still challenged by heterogeneous...     

卫星USB测控副载波同步算法研究

吉林一号卫星测控采用USB测控体制,遥控接收采用FFT+DPLL1+DPLL2的架构,FFT主要实现对载波的粗捕,DPLL1在FFT的基础上实现对载波相位的精跟踪,DPLL2实现副载波的跟踪。对遥控副载波跟踪所用到的数字PLL技术进行了研究,首先给出了载波多普勒折算到副载波上的方法,然后对模拟PLL数字化进行了详细的论述,并设计了遥控副载波同步用的PLL2,对其稳定性、快捕带及快捕时间、捕获带和捕获时间、同步速率等进行了分析和仿真。结果表明,该方法具有捕获时间短、跟踪精度高、稳定性好等特点,易于数字化实现,已成功在吉林一号系列卫星中得到应用。     

Speech synthesis with face embeddings

Human beings are capable of imagining a person’s voice according to his or her appearance because different people have different voice characteristics. Although researchers have made great progress in single-view speech synthesis, there are few studies on multi-view speech synthesis, especially the speech synthesis using face images. On the basis of implicit relationship between the speaker’s face image and his or her voice, we propose a multi-view speech synthesis method called SSFE (Speech Synthesis with Face Embeddings). The proposed SSFE consists of three parts: a voice encoder, a face encoder and an improved multi-speaker text-to-speech (TTS) engine. On the one hand, the proposed voice encoder generates the voice embeddings from the speaker’s speech and the proposed face encoder extracts the voice features from the speaker’s face as f-voice embeddings. On the other hand, the multi-speaker TTS engine would synthesize the speech with voice embeddings and f-voice embeddings. We have conducted extensive experiments to evaluate the proposed SSFE on the synthesized speech quality and face-voice matching degree, in which the Mean Opinion Score of the SSFE is more than 3.7 and the matching degree is about 1.7. The experimental results prove that the proposed SSFE method outperforms state-of-the-art methods on the synthesized speech in terms of speech quality and face-voice matching degree.

     

Face aging with pixel-level alignment GAN

Applied Intelligence - Face aging is of great significance in cross-time identity verification problem. However, there is still a huge gap between the synthesized face image and the real face in...     

Bioinspired yeast microcapsules loaded with self-assembled nanotherapies for targeted treatment of cardiovascular disease

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Effects of Ti and Mn Co-substitution on P4mm BiFeO3: An Ab Initio Calculation

Tetragonal BiFeO₃ (BFO), which has a giant spontaneous polarization, has attracted a great deal of attention recently. In this paper, we systematically study the structural, magnetic, electronic and optic properties of BFO, BiFe_0.75Mn_0.25 O ₃ (BFMM), and BiFe_0.75Ti_0.125Mn_0.125 O ₃ (BFMT). Results show that doping Ti and Mn into the Fe sites increases the c/a ratio and enhances the magnetization of BiFeO₃ from 0 to 5 μ_B. The crystal symmetry changes from orthogonality to tetragonality with half of the Mn atoms being replaced by Ti in BiFe_0.75Mn_0.25 O ₃, which suppresses the energy splitting of the Mn 3d orbitals and thus enlarge the band gap to 1.21 eV for BiFe_0.75Ti_0.125Mn_0.125 O ₃. Our calculated Bader charge and charge density difference show that the smallest volume of BiFe_0.75Mn_0.25 O ₃ arises from the strong Mn–O bonds in BiFe_0.75Mn_0.25 O ₃. Further investigations indicate similar optical behaviors for BiFeO₃ and BiFe_0.75Ti_0.125Mn_0.125 O ₃. However, BiFe_0.75Mn_0.25 O ₃ exhibits strong absorption in the infrared region for the transition from O 2p to Mn \({e_{g}^{2}}\) and \(t_{2g}^{3}\).