"互联网+"时代个性化试题推荐方法

"互联网+"环境下,网上自主学习已成常态.文章提出一种个性化试题推荐方法,先通过认知诊断模型诊断出学生的认知状态,再采用协同过滤方法推荐试题,能给学生推荐准确且可解释性的试题.     

Augmented Online Sequential Quaternion Extreme Learning Machine

Neural Processing Letters - Online sequential extreme learning machine (OS-ELM) is one of the most popular real-time learning strategy for feedforward neural networks with single hidden layer due...     

An ultrahigh-resolution image encryption algorithm using random super-pixel strategy

Multimedia Tools and Applications - Almost all existing image encryption algorithms are only suitable for low-resolution images in the standard image library. When they are used to encrypt...     

Conspiracy vs science: A large-scale analysis of online discussion cascades

World Wide Web - With the emergence and rapid proliferation of social media platforms and social networking sites, recent years have witnessed a surge of misinformation spreading in our daily life....     

A Sequential Design Approach for Switching ℌ∞ LPV Control

This paper proposes a sequential design scheme for switching ℌ_∞ LPV (Linear Parameter-Varying) control, aiming to reduce the computational complexity of the associated optimization problem. Different from the traditional approach that simultaneously designs switching LPV controllers and solves a high-dimensional optimization problem, the proposed sequential design approach renders a bundle of low-dimensional optimization problems to be solved iteratively. Individual ℌ_∞ LPV controller for each subregion is synthesized by independent PLMIs (Parametric Linear Matrix Inequalities) to guarantee ℌ_∞ performance, and controller variables are interpolated on the overlapped subregions such that the ℌ_∞ performance is also guaranteed on the overlapped subregion. Numerical examples are used to demonstrate the effectiveness of this method to reduce the computational load in each design iteration and improved ℌ_∞ performance over the conventional simultaneous design method with well-tuned interpolation coefficient.

     

A Novel Filtering Based Recursive Estimation Algorithm for Box-Jenkins Systems

International Journal of Control, Automation and Systems - This paper presents a novel filtering based multi-innovation estimation algorithm for output-error autoregressive moving average (i.e.,...     

Actuator and Sensor Fault Detection and Isolation for Uncertain Switched Nonlinear System Based on Sliding Mode Observers

International Journal of Control, Automation and Systems - In this paper, we discuss actuator fault and sensor fault detection and isolation (FDI) problems for a class of switched nonlinear systems...     

音频大地电磁测深在某隧道工程中的应用

音频大地电磁(AMT)在隧道的工程地质勘察是一种非常有效的方法,它具有不受高阻屏蔽、轻便、探测深度相对较大等优点,在宏观上可以查明隧道地层岩性分界、地质构造及其赋水性。以某隧道音频大地电磁勘察为例,分别对AMT的采集手段、工频干扰去噪、静态校正、反演方法等关键技术问题进行分析,并结合实际资料对该工作区的地层分布、断层及其破碎带的赋水情况等进行分析和解释,在其应用中取得了理想的效果。     

An automatic parameter calibration method for the SWAT model in runoff simulation

Runoff simulation is highly significant for hydrological monitoring, flood peak simulation, water resource management, and basin protection. Runoff simulation by distributed hydrological models, such as the soil and water assessment tool (SWAT) model which is the most widely used, is becoming a hotspot for hydrological forecasting research. However, parameter calibration is inefficient and inaccurate for the SWAT model. An automatic parameter calibration (APC) method of the SWAT model was developed by hybrid of the genetic algorithm (GA) and particle swarm optimization (PSO). Multi‐station and multi‐period runoff simulation and accuracy analysis were conducted in the basin of the Zhangjiang River on the basis of this hybrid algorithm. For example, in the Yaoxiaba Station, the calibration results produced an R² of 0.87 and Nash Sutcliffe efficiency (NSE) index of 0.85, while verification results revealed an R² of 0.83 and NSE of 0.83. Results of this study show that the proposed method can effectively improve the efficiency and simulation accuracy of the model parameters. It can be concluded that the feasibility and applicability of GA‐PSO as an APC method for the SWAT model were confirmed via case studies. The proposed method can provide theoretical guidance for many hydrological research fields, such as hydrological simulation, flood prevention, and forecasting.     

一种双U形缺陷地结构低通滤波器的设计

基于双U形缺陷地结构设计了一种低通滤波器。首先利用三维电磁场仿真软件分析了双U形DGS结构的S参数频响特性,然后利用该DGS结构加工制作了DGS结构低通滤波器,实验室测得该滤波器3 dB截止频率为3．26 GHz,通带范围内波纹最大是0．4 dB。插入损耗大于20 dB的阻带宽度为5．2 GHz。