UMTS及EPC网络QoS机制的研究

随着社会的发展,用户对业务质量的需求也日益提高,为此3GPP组织加强了对QoS的研究,在UMTS阶段引入了端到端QoS机制,并在LTE阶段对QoS机制进行了扩展和增强,目前QoS的研究是3GPP研究的一个热点。本文对3GPP移动通信网QoS演进进行了介绍,分析了UMTS和EPC网络的QoS实现机制,并对两种QoS实现机制进行了分析。     

一种红外探测器效应的实时模拟方法

文中剖析了Ogre渲染引擎的工作原理,描述了基于GPU的后处理技术,利用Ogre渲染引擎通过GPU实现了二维快速傅里叶变换,添加了探测器成像系统调制传递函数(MTF),实现了系统线性噪声和随机噪声的添加,模拟了实时三维红外场景中的探测器效应.     

Improved LUT Technique for HPA Nonlinear Pre-Distortion in OFDM Systems

In this paper, we focus on the Look-up Table (LUT) technique for the compensation of HPA nonlinear distortion. An improved LUT method is proposed with better performance compared with conventional LUT technique in terms of convergence speeds, BER and total degradation (TD). It can get over 8 dB gain in out-of-band spectrum re-growth suppression and about 0.3 dB BER performance gain than conventional LUT technique with the same iteration times. Also, we propose an actual application of HPA with pre-distorter in OFDM transmitter. Ai Bo was born in Shannxi Province in China on February 7, 1974. He received a BSc. Degree from Engineering Institute of Armed Police Force in 1997, a Master and Dr. degree from Xidian University in 2002 and 2004 in China respectively, and now working as a post dr. in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) of China. He is an editorial committee member of journal of “Computer Simulations”, “Information and Electronic Engineering”, an IEEE member and a senior member of Electronics Institute of China (CIE). He has published over 60 scientific papers in his research area till now. His current interests are the research and applications of OFDM techniques with emphasis on synchronization and HPA linearization techniques. Yang Zhi-Xing graduated from Tsinghua University, P.R. China in 1970. He is now a Professor and Deputy Director of State Key Lab. on Microwave and Digital Communication at the Department of Electronic Engineering and the Director of the DTV R&D Center in Tsinghua University. As a DTV technical expert for the Chinese government, Professor Yang has also been a member of the DTV standardization Committee of China and a leader of the DTV Standardization Harmonizing Group in Ministry of Information Industry of China. His major research interests include broadband information transmission technologies and DTV broadcasting systems. Pan Chang-Yong received the B.S. and M.S. degrees from the Department of Electronic Engineering in Tsinghua University, P.R. China, in 1996 and 1999, respectively. He is now an associate professor in the Department of Electronic Engineering and a member of the DTV R&D Center in Tsinghua University. His research interests are in the areas of broadband wireless transmission systems and satellite communications. Zhang Tao-Tao was born in Shandong Province in China in 1982, he received BSc. degree from Tsinghua University in 2004 and now pursing his Master degree in Dept. of E&E, state of key lab. on microwave and digital communications in Tsinghua University in China. His research interests is the power amplifier linearization techniques. Wang Yong was born in Shannxi Province in China in 1976. He received a BSc., a Master and a Dr. Degree from Xidian University in China in 1997, 2002 and 2005, respectively, and now is an associate professor in Xidian University. He has once participated in the key research project on HDTV in TEEG (Team of Engineering Expert Group) in China and is an IEEE Member. His interests are broadband multimedia communications. Ge Jian-Hua was born in September, 1961 in JiangSu Province in China. He received the B.Sc., Master and Ph.D. degree from Xidian University in 1982, 1985 and 1989, respectively. He is now the professor in both Xidian University in Xi’an and Shanghai Jiaotong University in Shanghai. He is the senior member of Chinese Electronics Institute. He has won lots of scientific and technical prizes in China and published many papers. His interests are transmission communications and web security.     

Towards the performance evaluation of 4th generation wireless communication standards: LTE versus Mobile WiMAX

Advances in wireless communication protocols and networking toward support of the next generation of mobile and radio broadband technologies have contributed to a strong competition among various telecommunication standards in particular Long Term Evolution (LTE) and Mobile Worldwide Interoperability for Microwave Access (WiMAX). In this paper, we provide an in‐depth comparison analysis of LTE and Mobile WiMAX at the physical (PHY) layer by studying the most similar PHY configuration scenarios for these two technologies. Our study includes a throughput analysis of downlink (DL) and uplink (UL) transmissions in time division duplex with the least overhead possible and different antenna schemes as well as modulation and code rates. This study also performs an overhead analysis in both protocols to provide a more in‐depth understanding of the PHY layer capacity in various PHY layer configurations. Our simulation results generally show higher performance for LTE in both DL and UL transmission with 7 Mbps in DL and 5 Mbps in UL, when using one antenna port. However, by increasing the number of antennas for multiple‐input/multiple‐output configurations, the results illustrate a reduction in the performance of LTE compared to Mobile WiMAX. This arises from the increase in reference signal overhead in LTE from 4.7% in single‐input/single‐output (SISO) to 14.28% in 4 × 4 multiple‐input/multiple‐output (MIMO). Copyright © 2013 John Wiley & Sons, Ltd.     

HL7在计算机中应用模式探讨

目前HL7(HealthLevelSeven)在国内经过一段时间的宣传、培训普及,已经开始逐步为国内医疗信息市场所认识和了解,但如何在实际应用中使用HL7标准,目前在国内还缺乏很多的认识和实践。介绍了HL7的两种应用模式,并对HL7在国内本地化过程中存在的问题进行了一些探讨。     

e-Health in Australia: A synthesis of thirty years of e-Health initiatives

This paper provides an overview of the history of e-Health initiatives in Australia. It highlights the importance of contextual factors in their evolution and the way in which certain initiatives have been managed. The first section outlines the development of e-Health systems in Australia from their inception to the present day. Then, Australia’s e-Health system is evaluated in relation to comparable countries using social mechanism theory. This provides a process-based approach for understanding the relationship between process, context and outcomes in the evaluation of e-Health initiatives in Australia and in comparable countries.     

刺五加雌、雄花的花柱引导组织结构观察

利用光学显微镜、透射电子显微镜观察了刺五加(Eleutherococcus senticosus)雌、雄花的花柱及其引导组织的结构。结果表明:1.刺五加花柱处合生心皮内表面未完全融合,形成由中心向四周分支的裂缝;2.雌性花柱较雄性花柱,引导组织更为发达;3.发育过程中引导组织细胞内不断有储存为脂体的营养物质分解,并分泌到细胞间隙;4.传粉后,雌花花柱引导组织的部分细胞发生降解,形成大的溶生的细胞间隙,花粉管从中穿过,而雄花花柱中未见溶生的细胞间隙,亦未见花粉管穿过。     

逐点插入法在三维地质建模中的运用

随着科学计算可视化技术和地质信息技术的发展,三维地质建模逐渐成为石油勘探、岩土工程、GIS和科学计算可视化等领域研究与应用的热点。本文主要介绍了在三维地质建模中常用的三角剖分算法中的逐点插入法,在实际运用中进行了改进,对三维空间中的原始数据点进行三角网化并构造地质体。     

Dopamine: Just the Right Medicine for Membranes

Mussel‐inspired chemistry has attracted widespread interest in membrane science and technology. Demonstrating the rapid growth of this field over the past several years, substantial progress has been achieved in both mussel‐inspired chemistry and membrane surface engineering based on mussel‐inspired coatings. At this stage, it is valuable to summarize the most recent and distinctive developments, as well as to frame the challenges and opportunities remaining in this field. In this review, recent advances in rapid and controllable deposition of mussel‐inspired coatings, dopamine‐assisted codeposition technology, and photoinitiated grafting directly on mussel‐inspired coatings are presented. Some of these technologies have not yet been employed directly in membrane science. Beyond discussing advances in conventional membrane processes, emerging applications of mussel‐inspired coatings in membranes are discussed, including as a skin layer in nanofiltration, interlayer in metal‐organic framework based membranes, hydrophilic layer in Janus membranes, and protective layer in catalytic membranes. Finally, some critical unsolved challenges are raised in this field and some potential pathways are proposed to address them.     

An empirical study of factors influencing cloud adoption among private sector organisations

In many developing countries such as Saudi Arabia the adoption of cloud computing is still at an early stage. This research aims to investigate the influencing factors in the decision to adopt cloud computing in the private sector. An integrated model is proposed incorporating critical factors derived from a literature review, along with other factors (such as physical location) that have not been examined in previous studies as main factors in the organisation’s decision to adopt cloud services. Data were collected from 300 IT staff in different organisations in the private sector in Saudi Arabia, in order to test the cloud adoption model and explore factors that were positively or negatively associated with cloud adoption. The most influential determinants of cloud adoption were found to be quality of service and trust. However, security and privacy concerns still prevent cloud adoption in this country. This study also showed that the effect of these variables differed according to organisation size and in adopter and non-adopter companies. Overall, these research findings provide valuable guidelines to cloud providers, managers, and government policy makers on ways of encouraging the spread of cloud computing in Middle Eastern countries and increasing its implementation, particularly in Saudi Arabia.