The Efficiency of Engineering Traffic Across Network Boundaries

With the arrival of wideband packet and circuit-oriented data services, it becomes a challenge to provide efficiently the desired quality of service for speech, packet data, and real-time data on a network. As these diverse networks will coexist, architectural studies on integrated heterogeneous networks suggest that a common radio resource manager be used to coordinate radio resource allocation between diverse network types. Initial studies show that supernets, which engineer traffic across wireless networks, are more efficient than operating separate cellular/wireless networks. Increased sharing occurs in supernets because a larger number of services compete for a larger pool of resources. If sharing can be shown to be efficient in general, then supernets should likewise be more efficient. This study decomposes the two-dimensional Markov chain to prove when sharing is beneficial and when it is not.     

CONVERGENCE OF IMPLICIT ITERATIVE PROCESS WITH ERRORS FOR A FINITE FAMILY OF ASYMPTOTICALLY NONEXPANSIVE MAPPINGS

The purpose of this article is to study the weak and strong convergence of implicit iteration process with errors to a common fixed point for a finite family of asymptotically nonexpansive mappings and nonexpansive mappings in Banach spaces. The results presented in this article extend and improve thecorresponding results of [1, 2, 4-9, 11-15].     

计算机网络安全概述

简介了网络信息安全的含义，攻击互联网的类型，网络安全机制应用 具有的功能以及网络信息安全常用技术，最后展望了网络信息安全前景。     

变频调速应用技术（九） 第五讲 知己知彼用变频（上）

本文分析了异步电动机变频调速时的基本特性。介绍了应用变频拖动系统时，必须满足的基本条件和实际工作中常见的误区。     

Focusing on the Needs: Experiences of Developing a Data Science Program

Donoho’s article “50 Years of Data Science” is a well-thought explanation of a newly developed discipline called “data science.” In this article, we examine his explanations and suggestions about data science, follow-up on some of the issues he mentioned, and share our experiences in developing a data science curriculum and the teaching of related courses.     

Field-based hypotheses on advancing standards for mathematical practice

The Common Core State Standards in Mathematics (CCSSM, 2010) are organized around two types of standards: the standards for mathematical content and standards for mathematical practice. The central goal of this paper is to present cognitive and instructional analyses of standards for mathematical practice through a discussion of field-based activities with inservice secondary mathematics teachers and students. A potential value of the study is that it provides researchers with specific field-based hypotheses on advancing standards for mathematical practice.     

Allocating fixed costs and common revenue via data envelopment analysis

An issue of considerable importance involves the allocation of fixed costs or common revenue among a set of competing entities in an equitable way. Based on the data envelopment analysis (DEA) theory, this paper proposes new methods for (i) allocating fixed costs to decision making units (DMUs) and (ii) distributing common revenue among DMUs, in such a way that the relative efficiencies of all DMUs remain unchanged and the allocations should reflect the relative efficiencies and the input-output scales of individual DMUs. To illustrate our methods, numerical results for an example are described in this paper.     

Comment on “New types of exact solutions for nonlinear Schrodinger equation with cubic nonlinearity”

In this comment we analyze the paper [Abdelhalim Ebaid, S.M. Khaled, New types of exact solutions for nonlinear Schrodinger equation with cubic nonlinearity, J. Comput. Appl. Math. 235 (2011) 1984-1992]. Using the traveling wave, Ebaid and Khaled have found “new types of exact solutions for nonlinear Schrodinger equation with cubic nonlinearity”. We demonstrate that the authors studied the well-known nonlinear ordinary differential equation with the well-known general solution. We illustrate that Ebaid and Khaled have looked for some exact solution for the reduction of the nonlinear Schrodinger equation taking the general solution of the same equation into account.     

Design of 3.1–10.6 GHz ultra-wideband CMOS low noise amplifier with current reuse technique

A new low complexity ultra-wideband 3.1–10.6 GHz low noise amplifier (LNA), designed in a chartered 0.18 μm RFCMOS technology, is presented in this paper. The ultra-wideband LNA only consists of two simple amplifiers with an inter-stage inductor connected. The first stage utilizing a resistive current reuse and dual inductive degeneration techniques is used to attain a wideband input matching and low noise figure. A common source amplifier with inductive peaking technique as the second stage achieves high flat gain and wide the −3 dB bandwidth of the overall amplifier simultaneously. The implemented ultra-wideband LNA presents a maximum power gain of 15.6 dB, a high reverse isolation of −45 dB and a good input/output return losses are better than −10 dB in the frequency range of 3.1–10.6 GHz. An excellent noise figure (NF) of 2.8–4.7 dB was obtained in the required band with a power dissipation of 14.1 mW under a supply voltage of 1.5 V. An input-referred third-order intercept point (IIP3) is −7.1 dBm at 6 GHz. The chip area including testing pads is only 0.8 mm × 0.9 mm.     

交流变频技术在大型铸造起重机的应用方案探讨

本文简要介绍了大型铸造起重机结构形式和工艺特点,以及交流变频技术目前发展特点,针对铸造起重机的工艺特点和各机构的负载特点,分析了交流变频技术在大型铸造起重机中应用的可行性和先进性。