网络电话终将浮出水面

随着计算机网络技术的发展,一种新的网络电话已崭露头角,它以独特的优势向传统电话发起了挑战,有望很快与之平分秋色。     

超导器件在军事和工程化方面的研究及应用进展综述(上)

对超导器件在国内外军事领域上的研究和应用进展进行了综述,分析了目前我国超导器件研制以及在武器装备上应用所面临的主要问题,提出了解决的办法,并重点介绍了中国电子科技集团公司第16所以及中电集团低温电子技术研发中心的研究成果,并提出了加快我国超导器件在武器装备上应用的建议。     

“一带一路”背景下厦门港海铁联运的发展研究

文章对“一带一路”政策下厦门港海铁联运市场的发展机遇进行了分析, 结合厦门港的海铁联运发展现状, 探讨其发展过程中的瓶颈, 并提出了以“一带一路”为契机推动厦门港海铁联运发展的建议。     

浅析电信运营商物联网发展策略

通过对物联网产业的分析研究,探讨了运营商近期物联网的发展定位、业务策略,以期为运营商物联网业务的开展提供参考和借鉴。     

40G／100G标准化现状及发展趋势

随着40G技术的规模商用以及100G技术的逐渐成熟,40G/100G标准化与产业应用关系更为密切,本文分析了40G/100G技术现状和标准化进展,同时对40G/100G技术后续发展趋势进行了较深入的探讨。     

广东省电子元器件产业发展现状及发展战略

广东省电子元器件产业作为广东省电子信息产业的基石,支撑着广东省电子信息产业的快速发展。一直以来,广东省电子元器件产业都位居全国第一,但近两年已经被江苏省超越。该文将深入分析广东省电子元器件产业的现状,剖析其存在的问题,围绕其面临的发展形势,指出其应采取的发展战略。     

基于ANP的物联网产业发展指标评价探究

从技术创新扩散能力、环境支撑能力两个方面,构建物联网产业发展指标体系;考虑到指标间的相互依赖性及反馈性,提出了基于网络层次分析法的物联网产业发展指标体系,为今后我国物联网产业发展水平评价提供科学的指标体系,研究结果表明本模型评估结果较传统层次分析法更具可信度。     

Minimum SNR and acquisition for bias-free estimation of fractional anisotropy in diffusion tensor imaging - a comparison of two analytical techniques and field strengths

Although it is known that low signal-to-noise ratio (SNR) can affect tensor metrics, few studies reporting disease or treatment effects on fractional anisotropy (FA) report SNR; the implicit assumption is that SNR is adequate. However, the level at which low SNR causes bias in FA may vary with tissue FA, field strength and analytical methodology. We determined the SNR thresholds at 1.5 T vs. 3 T in regions of white matter (WM) with different FA and compared FA derived using manual region-of-interest (ROI) analysis to tract-based spatial statistics (TBSS), an operator-independent whole-brain analysis tool. Using ROI analysis, SNR thresholds on our hardware-software magnetic resonance platforms were 25 at 1.5 T and 20 at 3 T in the callosal genu (CG), 40 at 1.5 and 3 T in the anterior corona radiata (ACR), and 50 at 1.5 T and 70 at 3 T in the putamen (PUT). Using TBSS, SNR thresholds were 20 at 1.5 T and 3 T in the CG, and 35 at 1.5 T and 40 at 3 T in the ACR. Below these thresholds, the mean FA increased logarithmically, and the standard deviations widened. Achieving bias-free SNR in the PUT required at least nine acquisitions at 1.5 T and six acquisitions at 3 T. In the CG and ACR, bias-free SNR was achieved with at least three acquisitions at 1.5 T and one acquisition at 3 T. Using diffusion tensor imaging (DTI) to study regions of low FA, e.g., basal ganglia, cerebral cortex, and WM in the abnormal brain, SNR should be documented. SNR thresholds below which FA is biased varied with the analytical technique, inherent tissue FA and field strength. Studies using DTI to study WM injury should document that bias-free SNR has been achieved in the region of the brain being studied as part of quality control.     

数据挖掘在教育教学中的应用综述

随着教育信息化的不断发展,基于数据库技术的数据挖掘与教育教学的联系也越来越紧密。通过对国内外数据挖掘在教育教学领域中的应用研究相关文献进行分析,从数据挖掘相关技术的角度出发,总结并归纳了各自在该领域中的应用和研究现状。最后提出了数据挖掘在该领域研究中存在的一些问题与难题以及发展前景。     

Quality in (analytical) R&D – ideas for the next step after EURACHEM/CITAC Guide 2

 The EURACHEM/CITAC Guide 2 is an important step towards the establishment of a quality assurance system in analytical research and development. But it is only the first step because it focuses on the metrological characteristics. In addition to Guide 2 there should be a supplementary guide providing assistance for effective and quality-orientated management of research groups.