Preservice teachers’ mathematics task modification for emergent bilinguals

Implementing mathematically challenging tasks is difficult for teachers when working with emergent bilinguals because cognitively demanding tasks in mathematics commonly have high language demand. Currently, inadequate teacher preparation for teaching emergent bilinguals is becoming a significant concern in the United States as this population of students is rapidly growing. This study investigated how two mathematics preservice teachers (PSTs) support middle school emergent bilinguals to understand cognitively demanding mathematical problems through task modification. Fieldwork with a concurrent intervention was designed for the PSTs to work with emergent bilinguals in a one‐on‐one setting. The PSTs modified cognitively demanding mathematics tasks and designed a lesson for the emergent bilinguals based on the modified tasks. The results revealed that the task modification made by the PSTs tended to shift from reducing cognitive demands in mathematics and language to maintaining the demands through learning strategies of contextual support.     

Numerical analysis for the quadratic matrix equations from a modification of fixed‐point type

In this paper, we study the quadratic matrix equations. To improve the application of iterative schemes, we use a transform of the quadratic matrix equation into an equivalent fixed‐point equation. Then, we consider an iterative process of Chebyshev‐type to solve this equation. We prove that this iterative scheme is more efficient than Newton's method. Moreover, we obtain a local convergence result for this iterative scheme. We finish showing, by an application to noisy Wiener‐Hopf problems, that the iterative process considered is computationally more efficient than Newton's method.     

分析新课程理念下高职《电工电子技术》教学存在的问题及对策

在高职教学中,电工电子技术是工科类学生所必修的专业基础课程,是一项实践性非常强的课程,同时这门课程也具有较多的理论知识。在我国进行新一轮教学改革的背景下,如果有效提高高职电工电子技术教学的质量,成为高职教师面临的一个新课题。在本文中,笔者结合自身工作实际,从电工电子技术教学中存在的问题和应对策略两个方面做了探讨。     

An in-service primary teacher’s implementation of mathematical tasks: the case of length measurement and perimeter instruction

The purpose of this paper is to examine the cognitive demand levels of tasks used by an in-service primary teacher during length measurement and perimeter instruction and to examine a possible link between these tasks and the teacher’s mathematical knowledge in teaching. For this purpose, a case study approach was used and the data was drawn from classroom observations, semi-structured interviews, and field notes. Specific tasks from length measurement and perimeter instruction were presented and analyzed according to the Mathematical Tasks Framework. Then, how these tasks gave information about the teacher’s mathematical knowledge in teaching in the length measurement and perimeter topics was examined according to the Knowledge Quartet model. According to the findings of the study, the tasks used during length measurement and perimeter instruction were mostly categorized as low-level tasks. In addition, teacher’s mathematical knowledge in teaching affected the implementation of the tasks.     

Distributed Power Control for Energy Conservation in Hybrid Cellular Network with Device-to-Device Communication

Device-to-Device （D2D） com- munication has been proposed as a promising implementation of green communication to benefit the existed cellular network. In order to limit cross-tier interference while explore the gain of short-range communication, we devise a series of distributed power control （DPC） schemes for energy conservation （EC） and enhancement of radio resource utilization in the hybrid system. Firstly, a constrained opportunistic power control model is built up to take advantage of the interference avoidance methodology in the presence of service requirement and power constraint. Then, biasing scheme and admission control are added to evade ineffective power consumption and maintain the feasibility of the system. Upon feasibility, a non-cooperative game is further formulated to exploit the profit in EC with minor influence on spectral efficiency （SE）. The convergence of the DPC schemes is validated and their performance is confirmed via simulation results.     

在具有点到点通信的蜂窝网络中面向节能的分布式功率控制(英文)

Device-to-Device(D2D) communication has been proposed as a promising implementation of green communication to benefit the existed cellular network.In order to limit cross-tier interference while explore the gain of short-range communication,we devise a series of distributed power control(DPC) schemes for energy conservation(EC)and enhancement of radio resource utilization in the hybrid system.Firstly,a constrained opportunistic power control model is built up to take advantage of the interference avoidance methodology in the presence of service requirement and power constraint.Then,biasing scheme and admission control are added to evade ineffective power consumption and maintain the feasibility of the system.Upon feasibility,a non-cooperative game is further formulated to exploit the profit in EC with minor influence on spectral efficiency(SE).The convergence of the DPC schemes is validated and their performance is confirmed via simulation results.     

一种基于能量比较的音频零水印方案(英文)

Zero-watermark technique,embedding watermark without modifying carriers,has been broadly applied for copyright protection of images.However,there is little research on audio zerowatermark.This paper proposes an audio zero-watermark scheme based on energy relationship between adjacent audio sections.Taking use of discrete wavelet transformation(DWT),it gets power approximations,or energies,of audio segments.Then,it extracts the audio profile,i.e.the zero-watermark,according to the relative size of energies of consecutive fragments.The experimental results demonstrate that the proposed scheme is robust against general malicious attacks including noise addition,resampling,low-pass filtering,etc.,and this approach effectively solves the contradiction between inaudibility and robustness.     

新疆农职院教学管理系统的安全设计初探

基于降低新疆农职院教学管理系统被攻击和出错后能自我纠错的目的。采用软件工程的方法,进行对教学管理系统的业务流程分析、了解各种可能存在的安全风险,提出了对用户采用分层管理等解决方案。每层的用户权限有严格的规定,同时对系统管理员的权限有所限制。系统管理员是本系统权限最高,其次分别是教学秘书、教师和学生。得出结论,通过在本院应用该系统,由于提高了安全性能,使得该系统更加的稳健,免受不法分子的入侵,同时提高了工作效率。     

基于项目教学的课程系统的特征及其设计原则

本文从项目教学的需求与系统设计的矛盾入手提出问题,从基于项目教学课程管理系统的概念入手,分析了项目教学系统特征,并结合一般课程管理系统的共性,最终提出了基于项目教学的系统开发原则,用于指导项目化教学平台的开发。