Topology Discovery Sub-Layer for Integrated Terrestrial-Satellite Network Routing Schemes

With the booming development of terrestrial network, scaling terrestrial network over satellite network to build Integrated Terrestrial-Satellite Network(ITSN) and meanwhile to provide the global Internet access, has become ever more attractive. Naturally, the widely and successfully used terrestrial routing protocols are the promising protocols to integrate the terrestrial and satellite networks. However, the terrestrial routing protocols, which rely on propagating routing messages to discover New Network Topology(NNT) in the terrestrial network with rare topology changes, will suffer from overly numerous routing messages in satellite network whose topology frequently changes as satellites move. In this paper, a Topology Discovery Sub-layer for ITSN Routing Schemes(TDS-IRS) is firstly proposed to avoid the propagation of numerous routing messages by taking advantage of the movement predictability of satellite and the requirements of routing schemes to discover NNT in advance of topology change. Secondly, a Weighted Perfect Matching based Topology Discovery(WPM-TD) model is designed to conduct the NNT discovery on the ground. Thirdly, this paper builds a testbed with real network devices and meanwhile interconnect that testbed with real Internet, to validate that RS-TDS can discover NNT immediately with the less on-board overhead compared with optimized routing schemes. Finally, different network scenarios are applied to validate the WPM-TD, i.e., the core module of TDS-IRS. Extensive experiments show WPM-TD can work efficiently, avoiding the invalid NNT discovery and decreasing 20% ~ 57% of potential topology changes, which can also improve up to 47% ~ 105% of network throughput.

Robust optical mode converter based on topological waveguide arrays

Optical mode converters are essential for enhancing the capacity of optical communication systems. However, fabrication errors restrict the further improvement of conventional mode converters. To address this challenge, we have designed an on-chip TE0–TE1mode converter based on topologically protected waveguide arrays. The simulation results demonstrate that the converter exhibits a mode coupling efficiency of 93.5% near 1550 nm and can tolerate a relative fabrication error of 30%. Our design approach can be extended to enhance the robustness for other integrated photonic devices, beneficial for future development of optical network systems.

SOLUTIONS FOR A SYSTEM OF NONLINEAR RANDOM INTEGRAL AND DIFFERENTIAL EQUATIONS UNDER WEAK TOPOLOGY

In this paper, a Darbao type random fixed point theorem for a system of weak continuous random operators with random domain is first proved. When, by using the theorem, some existence criteria of random solutions for a systems of nonlinear random Volterra integral equations relative to the weak topology in Banach spaces are given. As applications, some existence theorems of weak random solutions for the random Cauchy problem of a system of nonlinear random differential equations are obtained, as well as the existence of extremal random solutions and random comparison results for these systems of random equations relative to weak topology in Banach spaces. The corresponding results of Szep, Mitchell-Smith, Cramer-Lakshmikantham, Lakshmikantham-Leela and Ding are improved and generalized by these theorems.

Topology Optimization Method for Microscale Structures Described with Integral Nonlocal Theory

The integration of additive manufacturing and topology optimization makes it possible to fabricate complex configurations,especially for microscale structures,which can guarantee the realization of high-performance structural designs.However,topology results often contain microstructures(several multicellular scales)similar to the characteristic length of local macrostructures,leading to errors in structural performance analysis based on classical theories.Therefore,it is necessary to consider the size effect in topology optimization.In this paper,we establish a novel topology optimization model utilizing the integral nonlocal theory to account for the size effect.The approach consists of an integral constitutive model that incorporates a kernel function,enabling the description of stress at a specific point in relation to strain in a distant field.Topology optimization structures based on nonlocal theory are presented for some benchmark examples,and the results are compared with those based on classical medium theory.The material layout exhibits significant differences between the two approaches,highlighting the necessity of topology optimization based on nonlocal theory and the effectiveness of the proposed method.

Robust Topology Optimization of Vehicle Suspension Control Arm

A robust topology optimization design framework is developed to solve lightweight structural design problems under uncertain conditions. To enhance the calculation accuracy and flexibility of the statistical moments of robust analysis, number theory integral method is applied to sample point selection and weight assignment. Both the structure topology optimization and number theory integral methods are combined to form a new robust topology optimization method. A suspension control arm problem is provided as a demonstration of robust topology optimization methods under loading uncertainties. Based on the results of deterministic and robust topology optimization, it is demonstrated that the proposed robust topology optimization method can produce a more robust design than that obtained by deterministic topology optimization. It is also found that this new approach is easy to apply in the existing commercial topology optimization software and thus feasible in practical engineering problems.

Optimization of a Si-SiO2 Waveguide Coupler for Photonic Integrated Circuits

In this paper, we demonstrated a compact Si-SiO2 waveguide coupler with a footprint of only 2 μm × 3 μm by topology optimization in the communication wavelength. The transmission was increased from 30% to 100%, much higher than other methods. Besides, the optimized structure did not incorporate other dielectric materials, facilitating fabrications and applications.

A Novel Integrated Circuit Driver for LED Lighting

A novel integrated circuit for driving LED lighting has been proposed, designed and fabricated. Besides the typical parts of LED driver, an integral part was added at the output terminal of error amplifier in the driver. In this way, a novel average current mode can be set up to take the place ordinary peak current control mode. In addition, a BUCK low-level topology was adopted, too. It can be used to drive up to eight 1 W HB LED lights with 350 mA constant current. In this way, the LED driver displays high performance, in which output current with less 1% error and total efficiency as high as 96%. The feasibility of the design has been verified by actual measurement on the fabricated chip.

内陆清洁能源基地±800kV/10000MW直流外送拓扑设计

大力开发大规模清洁能源基地是国家“十四五”现代能源体系规划明确的重点任务。针对藏东南地区大规模水电、光伏送出场景,计及新能源基地海拔高、输电走廊受限问题,设计了±800 kV/10000 MW多直流电压等级混合直流、多直流电压等级柔直和四端混合直流系统送出拓扑。针对沙戈荒地区风电、光伏送出场景,设计了±800 kV/10000 MW三端柔直、四端柔直和多直流电压等级混合直流系统送出拓扑。最后,在PSCAD/EMTDC仿真平台搭建了各拓扑方案的仿真模型,对比分析了各拓扑的技术特点。通过研究,以期为未来相关工程实践拓扑设计提供参考。

集成LCC-S拓扑的二维全向无线电能传输系统无盲区能量捕获方法研究

针对二维全向无线电能传输技术存在空间磁场完整度与电流控制策略复杂度的竞争问题,该文提出一种集成LCC-S拓扑的二维全向无线电能传输系统无盲区能量捕获方法。该系统以二维正交线圈为电磁耦合机构,并将其集成于LCC-S型补偿拓扑。同时提出一种自调整参数设计方法,实现系统在二维空间内产生时均旋转磁场以及系统的零相角输入。通过场-路耦合有限元模型分析系统在二维空间内磁场分布情况,随时间峰值磁场强度矢量轨迹为圆形。搭建集成型二维全向无线电能传输的实验样机,实验结果表明,该系统实现单一电源驱动下无盲区的二维全向电磁能量捕获。

指数有界n阶α次积分C群的紧性

利用指数有界n阶α次积分C群及其次生成元的定义,并借助经典算子理论的研究方法,给出了指数有界n阶α次积分C群紧的定义,从而推导出指数有界n阶α次积分C群的紧性的一些性质。

基于三相桥光储一体系统的建模与控制

为解决光伏发电具有波动性且伴有“弃光”现象的问题,提出了一种基于三相桥的光储一体转换器拓扑结构及相关控制策略。该结构能够实现光伏电源、蓄电池、负载之间的功率流动,并具有LLC谐振变换器的软开关性质、高效率、输入电压范围适应性更宽、高功率密度等优点。在控制策略方面,采用带有复合反馈的电导增量法来实现最大功率点跟踪;为实现双向DC-DC变换器共用电感和直流母线电压稳定,采用双频率控制方法确定电感,并实现电压外环电流内环双闭环控制;为保证输出负载电压稳定,LLC谐振转换器采用电压闭环的调频控制。最后,搭建了光储一体系统仿真模型与实验平台,仿真与实验结果表明:提出的新型光储一体系统结构简单,可以稳定运行且易于实现。

双面共体反射镜结构优化设计与分析

为了满足某同轴四反红外光学系统中主四双面共体反射镜的性能要求,需要镜体在高轻量化率的同时具有更高的刚度,保持两个镜面面形稳定。该文采用拓扑优化的方法,以刚度最大为优化目标,约束设计域体积分数的方式对双面共体反射镜初始模型进行优化。优化结果表明,主镜面与四镜面通过以光轴为中心呈辐射形排列的筋板连接时刚度较高;通过自由尺寸优化获得主、四镜面和筋板的最佳尺寸参数;参考优化结果设计主、四共体反射镜,最终方案轻量化率达到82.4%。对主四反射镜模态及1g重力对面形RMS的影响进行分析,求得一阶频率达到417 Hz;1g重力作用下反射镜面形变化最大为λ/22(λ=632.8 nm)。分析结果表明,优化后的镜体刚度足够,且具有较好的抵抗重力变形能力。按照优化后的设计方案进行反射镜的加工和测试,主、四镜面形RMS实测结果均约λ/7,满足红外光学系统的性能要求,证明了本文优化设计方法的有效性,为双面共体反射镜的设计提供一定的借鉴作用。

基于开绕组电机的电动汽车双电池集成充电系统准直接功率控制

针对基于开绕组永磁同步电机和双电池组驱动的电动汽车提出一种集成化充电拓扑,充电运行时将双逆变器和电机绕组复用为双PWM整流器及其输入侧滤波电感。在三相电压源型整流器(VSR)和开绕组永磁电机数学模型的基础上,将电网坐标系和电机坐标系相统一,分析了充电状态下的电磁转矩。实际运行时存在双电池剩余电量不相等的情况,导致充电时双通道功率不平衡,因此设计了一种准直接功率控制策略,以解决功率不平衡带来的转矩脉动问题。最后通过仿真和实验验证了该集成化充电拓扑的可行性。

车辆工程专业人才培养模式探究

在“大众创业、万众创新”浪潮下,创新创业教育与专业教育的融合(“专创”融合)逐渐成了提升高校人才培养质量的重要手段。本文立足于车辆工程专业,聚焦人才培养全过程,研究“课创赛”融合的培养模式,分析“课创赛”融合的内在逻辑关系,探索“课创赛”融合的教育范式。基于“课创赛”融合培养模式,分析专业课程之间内在联系,优化课程体系建设,构造专业知识培养与创新能力培养融合的课程拓扑结构;同时将学科竞赛融入课程体系,提升学生学习主动性,催生更多的高水平学科竞赛成果,培育满足专业需求的具有创新创业能力的复合型人才。

数字文旅的空间生产与文化拓扑

在文旅产业数字化发展趋势下,文旅空间具备了物质性、媒介性、社会性等特征,数字技术和数字媒介正在深度作用于文旅融合的发展逻辑中。在三元空间论的框架下,数字文旅的拓扑结构可通过空间实践的感知耦合、空间表象的远方再造和表征性空间的意义融合三重属性进行解读。通过选取数字导览、文旅游戏、数字沉浸展和文旅视听作为典型的数字文旅业态进行分析,可将其文化生产机制分为空间实践和文化折叠两种拓扑类型。以拓扑逻辑审视数字文旅的空间实践,文旅项目可通过以数字化关联衔接双重坐标,以跨时空耦合重塑远方边界,以动态叙事体促进意义联动来推动数字化业态的创新发展。

车载一体化配料装置上臂架结构优化设计研究

以某重点项目的车载一体化配料装置上臂架为研究对象,针对其轻量化、稳定性好、翻转可靠的性能要求,对其进行结构拓扑优化及尺寸优化。根据优化后的结果确定了臂架侧面腹杆以及底面连杆的具体布局和截面尺寸参数,然后把优化结果和实际市场主流尺寸规格相结合重新构建上臂架模型。最后数值分析表明:在保证上臂架力学特性的前提下,该优化方法减重147kg,节约了21%的材料,满足轻量化要求,最大变形量降低6mm,增强了结构的稳定性,最终实现优化的目标。

海上风电机组支撑结构一体化设计方法

受设计工作范围分工和责任的制约,风电机组设备厂商和风电场建设单位分别设计塔筒和导管架,这种分离式设计通过塔筒底部载荷传递并反复迭代确定结构型式及尺寸。此外,现有的海上风电机组导管架设计参考海洋石油平台等规范,忽略了海上风电机组的受力特点。上述两层原因较大程度上制约了支撑结构的力学性能,且设计迭代次数较多,并无法准确获取整体结构的动态响应。为解决上述问题,提出基于拓扑优化的导管架结构设计方法,并通过改变塔筒和导管架分界面位置,即扩大拓扑优化设计空间进一步提高结构性能。选取NREL 5 MW海上风电机组为研究对象,分别对比参考结构、拓扑优化结构和一体化设计结构的固有频率和不同极限工况下的最大变形。结果证明了所提出支撑结构一体化设计方法的有效性和优越性。

月球微电网——深空探测综合能源基地

针对月球科研站能源供需特点,提出具有“五强”技术特征、“五高”供应能力的月球数智化高可靠微电网综合能源基地蓝图,明确了以直流为主交流为辅的混合微电网基本形态、以电氢耦合为基本能量转换形式的“电-氢-氧-热-水”综合能源基地的建设愿景,并在地球建立全域、全态、全时数字孪生系统,支撑其安全稳定、高质高效运行。月球微电网综合能源基地建设是一项全局性、复杂性和开创性的系统工程,创新提出兆瓦级月球微电网电源结构、储能形式、网架形态以及系统拓扑结构、运行模式,提出基于月球科研站用能需求的三阶段发展设想,为我国深空探测能源供给提供全套解决方案。基于新质生产力形成的新供给,提出加强前沿技术、颠覆性技术多路径探索和交叉融合,尽早开展月球微电网综合能源基地研究的建议。月球微电网综合能源基地将有力促进地球新型电力系统的建设和发展。

A Hierarchical Model Architecture for Enterprise Integration in Chemical Industries

Towards integration of supply chain, manufacturing/production and investment decision making, this paper presents a hierarchical model architecture which contains six sub-models covering the areas of manufacturing control, production operation, design and revamp, production management, supply chain and investment decision making. Six types of flow, material, energy, information, humanware, partsware and capital are ciasified. These flows connect enterprise components/subsystems to formulate system topology and logical structure. Enterprise components/subsystems are abstracted to generic elementary and composite classes. Finally, the model architecture is applied to a management system of an integrated suply chain, and suggestion are made on the usage of the model architecture and further development of the model as well as imvlementation issues.

Existence of Solutions to a p-Laplacian Equation with Integral Initial Condition

In this paper, a class of one-dimension p-Laplacian equation with nonlocal initial value is studied. The existence of solutions to such a problem is obtained by using the topological degree method.