溯源维特鲁威人的本义

维特鲁威建筑论的核心是“建筑人体摹仿论”。遵从技艺创制的摹仿论,他构建了一个抽象的理想人体,以之作为建筑创制所摹仿的原本。以希腊化时代的“知识统一论”来溯源理想人体的本义,人的形象寓意人神同形的理性灵魂、人体比例的本质属性在于完美数及其可推演的关系、四肢展开的圆方外形指涉宇宙秩序。而体现建筑本质属性的均衡比例,也因摹仿而具有与理想人体“同一” 的属性。以此为基础,并依照时代的科学论,维特鲁威创建了古典科学意义上的建筑学。     

基于改进YOLOv5的输电线路鸟巢检测方法研究

输电线路上的鸟巢会对电力设备的安全运行构成威胁,甚至影响整个电力系统的稳定性。针对复杂场景下输电线路鸟巢检测方法适用性较差的问题,提出一种基于改进YOLOv5的输电线路鸟巢检测方法。该方法结合通道注意机制和空间注意机制设计特征平衡网络,以通道权值和空间权值作为引导,实现检测网络不同层次特征之间语义信息和空间信息的平衡。同时,为了避免因网络层数增加导致特征信息不断被弱化的问题,设计特征增强模块以捕获与鸟巢相关的通道关系和位置信息。最后,利用输电线路无人机巡检图像建立鸟巢数据集进行训练和测试。实验结果表明,所提出的输电线路鸟巢检测方法具有较强的泛化能力和适用性,同时也为电力图像缺陷检测提供技术参考。     

基于需求侧博弈的区域综合能源服务商最优运营策略

为了提高综合能源服务商运营服务的高效性、清洁性和经济性,提出了一种基于需求侧博弈的综合能源服务商最优运营策略。通过对综合能源服务商模型的分析,以用户能源消耗量确定系统碳排放量,建立了区域综合能源服务商碳排放模型,确定了园区的碳排放量。在此基础上,考虑了用户对用能成本波动的可承受能力和服务商应对用户用能变化的风险成本,分别以综合能源服务商全天利润最大、用户用能成本最小为目标函数,建立了综合能源服务商-多用户博弈优化模型。采用迭代搜索法得到纳什均衡解,从而确定服务商最优运营策略。最后以典型工业园区为例对所提策略进行仿真验证。结果表明,所研究的服务商运营策略有效降低了系统碳排放量,提高了综合能源服务商的经济效益和用户满意度。     

Ultrafast Switchable Passive Radiative Cooling Smart Windows with Synergistic Optical Modulation

Switchable passive radiative cooling (PRC) smart windows can modulate sunlight transmission and spontaneously emit heat to outer space through atmospheric transparent window, presenting great potential in building energy conservation. However, realizing stable and on-demand control of the cooling efficiency for PRC materials is still challenging. Herein, an electro-controlled polymer-dispersed liquid crystal (PDLC) smart window showing PRC property is designed and prepared by adding mid-infrared emitting reactive monomers into the conventional PDLC matrix. It is found that not only the electro-optical properties but also the PRC efficiency of PRC PDLC film are tunable by regulating the content of the mid-infrared emitting components, film thickness, and micromorphology. This advanced PRC PDLC material achieves a near/sub-ambient temperature when the solar irradiance is below 400 W m⁻² and can dynamically manage daytime cooling efficiency. Importantly, its PRC efficiency is capable of being tuned in an on-demand and ultrafast millisecond-scale way, whose controllable transparency enables multistage heat regulation. This study is hoped to provide new inspiration in the preparation of advanced optical devices and energy-efficient equipment.     

Light-Responsive Programmable Shape-Memory Soft Actuator Based on Liquid Crystalline Polymer/Polyurethane Network

Liquid crystalline polymers (LCPs), especially liquid crystalline elastomers (LCEs) can generate ultrahigh shape change amplitude but has lower mechanical strength. Although some attempts have been tried to improve the mechanical performance of LCE, there are still limitations including complicated fabrication and high actuation temperature. Here, a versatile method is reported to fabricate light-driven actuator by covalently cross-linking polyurethane (PU) into LCP networks (PULCN). This new scheme is distinct from the previous interpenetrating network strategy, the hydrogen bonds and covalent bonds are used in this study to improve the miscibility of non-liquid-crystalline PU and LCP materials and enhance the stability of the composite system. This material not only possesses the shape memory properties of PU but shows shape-changing behavior of LCPs. With a shrinkage ratio of 20% at the phase transition temperature, the prepared materials reached a maximum mechanical strength of 20 MPa, higher than conventional LCP. Meanwhile, the resulting film shows diverse and programmable initial shapes by constructing crosslinking density gradient across the thickness of the film. By integration of PULCN with near-infrared light-responsive polydopamine, local and sequential light control is achieved. This study may provide a new route for the fabrication of programmable and mechanically robust light-driven soft actuator.     

Future Event Prediction Based on Temporal Knowledge Graph Embedding

Accurate prediction of future events brings great benefits and reduces losses for society in many domains, such as civil unrest, pandemics, and crimes. Knowledge graph is a general language for describing and modeling complex systems. Different types of events continually occur, which are often related to historical and concurrent events. In this paper, we formalize the future event prediction as a temporal knowledge graph reasoning problem. Most existing studies either conduct reasoning on static knowledge graphs or assume knowledges graphs of all timestamps are available during the training process. As a result, they cannot effectively reason over temporal knowledge graphs and predict events happening in the future. To address this problem, some recent works learn to infer future events based on historical event-based temporal knowledge graphs. However, these methods do not comprehensively consider the latent patterns and influences behind historical events and concurrent events simultaneously. This paper proposes a new graph representation learning model, namely Recurrent Event Graph ATtention Network (RE-GAT), based on a novel historical and concurrent events attention-aware mechanism by modeling the event knowledge graph sequence recurrently. More specifically, our RE-GAT uses an attention-based historical events embedding module to encode past events, and employs an attention-based concurrent events embedding module to model the associations of events at the same timestamp. A translation-based decoder module and a learning objective are developed to optimize the embeddings of entities and relations. We evaluate our proposed method on four benchmark datasets. Extensive experimental results demonstrate the superiority of our RE-GAT model comparing to various baselines, which proves that our method can more accurately predict what events are going to happen.     

Leveraging Bioinspired Structural Constraints for Tunable and Programmable Snapping Dynamics in High-Speed Soft Actuators

Creating high-speed soft actuators will have broad engineering and technological applications. Snapping provides a power-amplified mechanism to achieve rapid movements in soft actuators that typically show slow movements. However, precise control of snapping dynamics (e.g., speed and direction of launching or jumping) remains a daunting challenge. Here, a bioinspired design principle is presented that harnesses a reconfigurable constraint structure integrated into a photoactive liquid crystal elastomer actuator to enable tunable and programmable control over its snapping dynamics. By reconfiguring constrained fin-array-shaped structure, the snapping dynamics of the structured actuator, such as launching or jumping angle and height, motion speed, and release force can be on-demand tuned, thus enabling controllable catapult motion and programmable jumping. Moreover, the structured actuators exhibit a unique combination of ultrafast moving speed (up to 2.5 m s⁻¹ in launching and 0.22 m s⁻¹ in jumping), powerful ejection (long ejection distance of ≈20 cm, 35 mg ball), and high jumping height (≈8 cm, 40 times body lengths), which few other soft actuators can achieve. This study provides a new universal design paradigm for realizing controllable rapid movements and high-power motions in soft matter, which are useful for building high-performance soft robotics and actuation devices.     

改进 8 邻域节点搜索策略 A ∗ 算法的路径规划

针对传统 A ? 算法所规划路径存在易触碰障碍物,冗余节点过多等问题。 提出了一种改进 8 邻域节点搜素策略 A ? 算法 的路径规划。 首先,在 A ? 算法中改进节点搜索条件,使得获得的节点与周围障碍物节点保持一定安全距离;然后利用垂距限 值法剔除改进后路径上的冗余节点,并保留关键节点;最后,基于关键节点利用 B 样条曲线拟合出一条平滑路径。 在不同规模 的多障碍物地图环境下进行多次实验与对比,结果表明,相比于传统 A ? 算法,提出的改进 A ? 算法,获得的路径节点与障碍物 节点的安全距离平均保持在 0. 46,路径节点平均减少了 66. 8%,有效提升机器人的工作效率和安全性。     

基于均值漂移聚类的开关柜局部放电异常检测

针对开关柜现场带电检测数据,提出一种基于多维特征量的均值漂移聚类算法,对开关柜的局部放电进行异常识别。采用局部放电检测数据的离散度、平均距离百分比、集中度和最大波动率指标全面量化开关柜局部放电的程度,并构建多维特征数据库;通过自动搜索偏移量的均值漂移聚类算法对开关柜的状态进行划分,并通过所给定的开关柜簇标签隶属度函数判定是否为异常点,由此实现开关柜的绝缘状态异常检测。对现场带电检测实际数据进行实例分析,验证该方法的可行性,为开关柜的绝缘状态异常识别提供一定的理论依据。     

Efficient Hardware Implementation Architectures for Long Integer Modular Multiplication over General Solinas Prime

Journal of Signal Processing Systems - Modular multiplication of long integers is a key component of elliptic curve cryptography and homomorphic encryption. The multiplication complexity can be...