基于新型掺钪氮化铝的级联马赫-曾德尔结构(解)复用器

在新型掺钪(Sc)氮化铝(Al1-xScxN)集成光学平台上设计了插入损耗低、传输通道谱线平坦的O波段四通道波分(解)复用器,并提出了优化方法。所设计的器件结构基于级联马赫-曾德尔干涉仪(MZI)滤波器,结合弯曲波导结构的定向耦合器改善波长敏感度。针对粗波分复用(CWDM)应用的特性,文章使用粒子群算法(PSO)提升器件性能优化的效率,通过调整器件结构的设计参数对四路通道的传输谱线质量进行优化。针对0%,9%,23%的掺Sc浓度,设计的解复用器表现出宽达约15.6nm的1-dB带宽和小于0.1dB的插入损耗,传输谱线呈“盒状”响应,各通道间串扰均优于-30.6dB。     

球面折反射成像的内螺纹螺距视觉测量系统

为了实现内螺纹参数的非接触、自动化在线测量,本文以通孔螺母和盲孔螺母为检测对象,提出了一种基于球面折反射全景成像原理的内螺纹螺距参数的机器视觉测量系统。系统采集经球面折反射得到的图像,随后分割出完整的内螺纹区域;采用对比度受限的自适应直方图均衡化算法提高图像对比度,并采用中值滤波与双边滤波的组合来保护螺纹边界信息;再使用Zernike矩边缘检测算法确定每条螺纹的亚像素边缘;最终,基于折反射成像理论计算得到内螺纹螺距尺寸。与计量用螺纹综合测量机的螺距测量值进行了对比,实验结果表明该系统的平均测量误差为0.018 5 mm,满足工业生产中内螺纹螺距精度的要求,检测效率高,可用于内螺纹在线视觉检测。本研究为圆柱形内壁尺寸测量和缺陷检测提供了一种参考方案。     

“虚实结合”的EDA课程设计实验教学案例

为提高学生的工程实践能力,我校EDA课程设计结合自研在线教学平台,采用案例式教学方式,锻炼和培养学生对EDA开发工具综合运用的能力和动手实践能力。EDA课程案例包括Matlab设计仿真、Modelsim仿真及D/A电路设计调试等EDA完整工程设计流程,线上实验平台提供远程硬件调试功能,学生可以随时随地通过线上实验平台对设计进行验证并与教师进行在线交流。该案例的成功实施有助于虚实结合的实践教学方法探索。     

基于龙伯格观测器的BLDC滑模控制系统仿真研究

针对无刷直流电机（BLDC）负载频繁改变导致电机调速性能差的问题,提出了一种基于负载转矩观测器的速度滑模控制方法。速度环采用滑模变结构控制方法,基于改进指数趋近律设计了速度滑模控制器;同时为了减小负载转矩扰动对电机运行状态的影响,基于龙伯格观测器设计了负载转矩观测器,通过观测器来估计实际的负载转矩并将观测器的输出前馈给速度滑模控制器来抵消负载转矩扰动的影响。为了验证提出方案的有效性,在MATLAB/Simulink仿真环境上搭建了仿真模型并进行了仿真分析,仿真结果表明基于负载转矩观测器和速度滑模控制器的无刷直流电机系统有着优异的性能,与传统PI控制相比,抗扰能力强、恢复时间短、转速响应快,证明了提出方案的有效性。     

Influence of green creativity on organizations: A case study from the perspectives of leaders and subordinates

The sustainability framework has a strong influence on the policies, practices and procedures of companies. Green creativity plays a pivotal role in the development of initiatives and innovations for the environmental pillar of sustainability. Based on a survey applied to a Portuguese company with an accredited environmental management system (N = 146), the findings reveal that green creativity is influenced in different ways when analysed from distinct perspectives. The leader's green creativity is positively influenced by the subordinate's green self-efficacy and personal identification with the leader, whereas the subordinate's green creativity is positively influenced by their green passion and green self-efficacy, and the leaders' green creativity. This study shows that green creativity develops differentially according to distinct job positions and expectations that in practice must be complementary and synergistic for its effective development.     

Phase-Separated Polyzwitterionic Hydrogels with Tunable Sponge-Like Structures for Stable Solar Steam Generation

Solar steam generation (SSG) through hydrogel-based evaporators has shown great promise for freshwater production. However, developing hydrogel-based evaporators with stable SSG performance in high-salinity brines remains challenging. Herein, phase-separated polyzwitterionic hydrogel-based evaporators are presented with sponge-like structures comprising interconnected pores for stable SSG performance, which are fabricated by photopolymerization of sulfobetaine methacrylate (SBMA) in water-dimethyl sulfoxide (DMSO) mixed solvents. It is shown that driven by competitive adsorption, the structures of the resulting poly(sulfobetaine methacrylate) (PSBMA) hydrogels can be readily tuned by the volume ratio of DMSO to achieve phase separation. The optimized phase-separated PSBMA hydrogels, combining the unique anti-polyelectrolyte effects of polyzwitterionic hydrogels, demonstrate a rapid water transport capability in brines. After introducing photothermal polypyrrole particles on the surface of the phase-separated PSBMA hydrogel evaporators, a stable water evaporation rate of ≈2.024 kg m⁻² h⁻¹ and high solar-to-vapor efficiency of ≈97.5% in a 3.5 wt.% brine are obtained under simulated solar light irradiation (1.0 kW m⁻²). Surprisingly, the evaporation rates remain stable even under high-intensity solar irradiation (2.0 kW m⁻²). It is anticipated that the polyzwitterionic hydrogel evaporators with sponge-like porous structures will contribute to developing SSG technology for high-salinity seawater applications.     

Picture-Neutrosophic Trusted Safe Semi-Supervised Fuzzy Clustering for Noisy Data

Clustering is a crucial method for deciphering data structure and producing new information. Due to its significance in revealing fundamental connections between the human brain and events, it is essential to utilize clustering for cognitive research. Dealing with noisy data caused by inaccurate synthesis from several sources or misleading data production processes is one of the most intriguing clustering difficulties. Noisy data can lead to incorrect object recognition and inference. This research aims to innovate a novel clustering approach, named Picture-Neutrosophic Trusted Safe Semi-Supervised Fuzzy Clustering (PNTS3FCM), to solve the clustering problem with noisy data using neutral and refusal degrees in the definition of Picture Fuzzy Set (PFS) and Neutrosophic Set (NS). Our contribution is to propose a new optimization model with four essential components: clustering, outlier removal, safe semi-supervised fuzzy clustering and partitioning with labeled and unlabeled data. The effectiveness and flexibility of the proposed technique are estimated and compared with the state-of-art methods, standard Picture fuzzy clustering (FC-PFS) and Confidence-weighted safe semi-supervised clustering (CS3FCM) on benchmark UCI datasets. The experimental results show that our method is better at least 10/15 datasets than the compared methods in terms of clustering quality and computational time.     

An Ophthalmic Evaluation of Central Serous Chorioretinopathy

Nowadays in the medical field, imaging techniques such as Optical Coherence Tomography (OCT) are mainly used to identify retinal diseases. In this paper, the Central Serous Chorio Retinopathy (CSCR) image is analyzed for various stages and then compares the difference between CSCR before as well as after treatment using different application methods. The first approach, which was focused on image quality, improves medical image accuracy. An enhancement algorithm was implemented to improve the OCT image contrast and denoise purpose called Boosted Anisotropic Diffusion with an Unsharp Masking Filter (BADWUMF). The classifier used here is to figure out whether the OCT image is a CSCR case or not. 150 images are checked for this research work (75 abnormal from Optical Coherence Tomography Image Retinal Database, in-house clinical database, and 75 normal images). This article explicitly decides that the approaches suggested aid the ophthalmologist with the precise retinal analysis and hence the risk factors to be minimized. The total precision is 90 percent obtained from the Two Class Support Vector Machine (TCSVM) classifier and 93.3 percent is obtained from Shallow Neural Network with the Powell-Beale (SNNWPB) classifier using the MATLAB 2019a program.     

A post quantum secure construction of an authentication protocol for satellite communication

Satellite's communication system is used to communicate under significant distance and circumstances where the other communication systems are not comfortable. Since all the data are exchanged over a public channel, so the security of the data is an essential component for the communicating parties. Both key exchange and authentication are two cryptographic tools to establish a secure communication between two parties. Currently, various kinds of authentication protocols are available to establish a secure network, but all of them depend on number–theoretical (discrete logarithm problem/factorization assumption) hard assumptions. Due to Shor's and Grover's computing algorithm number theoretic assumptions are breakable by quantum computers. Although Kumar and Garg have proposed a quantum attack-resistant protocol for satellite communication, it cannot resist stolen smart card attack. We have analyzed that how Kumar and Garg is vulnerable to the stolen smart card attack using differential power analysis attack described in He et al and Chen and Chen. We have also analyzed the modified version of signal leakage attack and sometimes called improved signal leakage attack on Kumar and Garg's protocol. We have tried to construct a secure and efficient authentication protocol for satellites communication that is secure against quantum computing. This is more efficient as it requires only three messages of exchange. This paper includes security proof and performance of the proposed authentication and key agreement protocol.     

基于STA-LSSVM的槽电压优化方法

针对铝电解过程中,槽电压的参数调节主要采用“试探法”、过于依赖技术员、耗时长等问题,提出了一种基于状态转移算法(State Transition Algorithm, STA)的槽电压优化方法。首先,采用灰色关联度分析方法确定槽电压模型的输入变量;然后,基于改进的最小二乘支持向量机(Least Square Support Vector Machine, LSSVM)建立槽电压软测量模型;最后,采用状态转移算法对槽电压优化控制模型进行实验,获得槽电压优化值和一组优化操作参数。结果表明,建立的槽电压软测量模型具有较高的预测精度,STA算法可寻到3.819 7 V的优化槽电压值,相较于优化前降低了115.8 mV,每吨铝直流电耗降低了363 kW·h,实现了槽电压的优化控制,达到了较好的节能降耗目的。