摘要：目的:提出一种适合永磁电机的冷却系统设计方案,降低电机本体温度。创新点:提出一种适合永磁电机热分析的CFD仿真模型。方法:采用计算流体动力学方法对包含冷却风扇的永磁电机进行空间三维热力学分析和优化设计。结论:本文提出并优化后的冷却风扇可有效降低永磁电机的最高和平均温度。

摘要：A type of millimeter-wave antenna array with flexible design is proposed for a variety of applications at 60 *** antenna array can be adjusted to be linearly or circularly polarized by simply changing the radiation part of the antenna *** gain,wideband,and high radiation efficiency characteristics can be achieved by adopting a low insertion loss feeding network and broadband antenna *** the linearly polarized antenna array,simulation results show that the impedance bandwidth of the 2×2 antenna subarray reaches 21.6%,while the maximum gain achieves 15.1 dBi and has a fluctuation of less than 0.4 dBi within the working *** results of the 8×8 linearly polarized antenna array show a bandwidth of 21.6%and a gain of(26.1±1)dBi with an antenna efficiency of more than 80%.For the 8×8 circularly polarized antenna array,simulation results show that an impedance bandwidth of 18.2%and an axial ratio(AR)bandwidth of 13.3%are *** and efficiency of up to 27.6 dBi and 80%are achieved,respectively.A prototype of antenna array is fabricated,and results are compared and analyzed.

摘要：鞭毛和纤毛独特的运动模式(如鞭毛的平面/螺旋波形式推进和纤毛的二维/三维不对称搏动)在众多生物的生命活动中起到至关重要的作用,这也启发了诸多仿生设计,尤其对于微型机器人系统。然而,与自然界中微生物能够从统一化的9+2轴丝生物结构中进化出多种运动模式不同的是,当前的仿生学仍然没有有效的工程策略去实现这样的智慧。在此,我们通过研究鞭毛和纤毛的内部结构及其内在驱动机制,推导出了一个统一的物理模型来描述微管弯曲及其所构建的宏观鞭毛/纤毛运动。基于该模型,我们进而提出了基于三通道的管状驱动概念,并相应地通过杆嵌入铸造工艺制造了一个三通道的管状驱动器。通过编程不同通道的驱动模式,这一管状驱动器不仅可以再现自然界中多样的二维及三维鞭毛/纤毛运动,还可以延展出更多的非对称纤毛搏动模式以实现低雷诺数下的有效推进。该研究加深了我们对微生物推进机制的理解,为仿生系统的设计提供了新灵感,并有望在广泛的工程领域中寻找到重要的应用场景。

摘要：This paper describes a novel model known as the shadow obstacle model to generate a realistic comer-tuming behavior in crowd simulation. The motivation for this model comes from the observation that people tend to choose a safer route rather than a shorter one when turning a comer. To calculate a safer route, an optimization method is proposed to generate the corner-turning rule that maximizes the viewing range for the agents. By combining psychological and physical forces together, a full crowd simulation framework is established to provide a more realistic crowd simulation. We demonstrate that our model produces a more realistic comer-turning behavior by comparison with real data obtained from the experiments. Finally, we per- form parameter analysis to show the believability of our model through a series of experiments.

摘要：The three-dimensional (3D)bioprinting technology has progressed tremendously over the past *** controlling the size, shape,and architecture of the bioprinted constructs,3D bioprinting allows for the fabrication of tissue/organ-like constructs with strong structural-functional similarity with their in vivo counterparts at high *** bioink,a blend of biomaterials and living cells possessing both high biocompatibility and printability,is a critical component of *** particular, gelatin methacryloyl (GelMA)has shown its potential as a viable bioink material due to its suitable biocompatibility and readily tunable physicochemical *** GelMA-based bioinks and relevant bioprinting strategies for GelMA bioprinting are briefly reviewed.

摘要：A trajectory generator based on vehicle kinematics model was presented and an integrated navigation simulation system was *** that the tight relation between vehicle motion and topography,a new trajectory generator for vehicle was proposed for more actual ***,a vehicle kinematics model was built based on conversion of attitude vector in different coordinate ***,the principle of common trajectory generators was ***,combining the vehicle kinematics model with the principle of dead reckoning,a new vehicle trajectory generator was presented,which can provide process parameters of carrier anytime and achieve simulation of typical actions of running ***,IMU(inertial measurement unit) elements were simulated,including accelerometer and *** setting up the simulation conditions,the integrated navigation simulation system was verified by final performance *** result proves the validity and flexibility of this design.

摘要：：In today＇s networks, load balancing and priority queues in switches are used to support various quality-of-service （QoS） features and provide preferential treatment to certain types of traffic. Traditionally, network operators use ‘traceroute＇ and ‘ping＇ to troubleshoot load balancing and QoS problems. However, these tools are not supported by the common OpenFlow-based switches in software-defined networking （SDN）. In addition, traceroute and ping have potential problems. Because load balancing mechanisms balance flows to different paths, it is impossible for these tools to send a single type of probe packet to find the forwarding paths of flows and measure latencies. Therefore, tracing flows＇ real forwarding paths is needed before measuring their latencies, and path tracing and latency measurement should be jointly considered. To this end, FlowTrace is proposed to find arbitrary flow paths and measure flow latencies in OpenFlow networks. FlowTrace collects all flow entries and calculates flow paths according to the collected flow entries. However, polling flow entries from switches will induce high overhead in the control plane of SDN. Therefore, a passive flow table collecting method with zero control plane overhead is proposed to address this problem. After finding flows＇ real forwarding paths, FlowTrace uses a new measurement method to measure the latencies of different flows. Results of experiments conducted in Mininet indicate that FlowTrace can correctly find flow paths and accurately measure the latencies of flows in different priority classes.

摘要：Spiking neural network,inspired by the human brain,consisting of spiking neurons and plastic synapses,is a promising solution for highly efficient data processing in neuromorphic ***,memristor-based neurons and synapses are becoming intriguing candidates to build spiking neural networks in hardware,owing to the close resemblance between their device dynamics and the biological ***,the functionalities of memristor-based neurons are currently very limited,and a hardware demonstration of fully memristor-based spiking neural networks supporting in-situ learning is very ***,a hybrid spiking neuron combining a memristor with simple digital circuits is designed and implemented in hardware to enhance neuron *** hybrid neuron with memristive dynamics not only realizes the basic leaky integrate-and-fire neuron function but also enables the in-situ tuning of the connected synaptic ***,a fully hardware spiking neural network with the hybrid neurons and memristive synapses is experimentally demonstrated for the first time,and in-situ Hebbian learning is achieved with this *** work opens up a way towards the implementation of spiking neurons,supporting in-situ learning for future neuromorphic computing systems.

摘要：This paper presents an image processing design flow for virtual fitting room (VFR) applications, targeting both personal computers and mobile devices. The proposed human friendly interface is implemented by a three-stage algorithm: Detection and sizing of the user's body, detection of reference points based on face detection and augmented reality markers, and superimposition of the clothing over the user's image. Compared to other existing VFR systems, key difference is the lack of any proprietary hardware components or peripherals. Proposed VFR is software based and designed to be universally compatible as long as the device has a camera. Furthermore, JAVA implementation on Android based mobile systems is computationally efficient and it can run in real-time on existing mobile devices.

摘要：This study presents the architecture and design flow of smart mobile sensing systems that performs wireless sensor data transmission, data analysis and display in real-time. Multiple wireless protocols are used for sensor data transmission including the Bluetooth, cellular data network and Wi-Fi for Internet access, and Near Field Communication (NFC). An Android smartphone is utilized to demonstrate the design concept of an Intelligent Personal Communication Node (iPCN) and to perform real-time sensor data acquisition, processing, analysis, display and transmission. Tested sensors include acceleration, temperature, electrocardiography (ECG) and phonocardiography (PCG). For computational capability tests, we have observed the signal processing performance of the smartphone by implementing fast Fourier transform (FFT) of the received ECG signal, and QRS detection algorithm for spontaneous heart beat rate (HBR) estimation. This system has also been tested for multiple sensor node communication and on-demand sensor data acquisition. The smart mobile sensing system can also be applied to any environment that requires real-time sensing and wireless remote monitoring.