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Tunable D peak in gated graphene

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Nano Research 2014年第3期7卷 338-344页

作者： Anna Ott Ivan A. Verzhbitskiy Joseph Clough Axel Eckmann thanasis Georgiou Cinzia Casiraghi Physics Departmen t Freie Universitat Berlin Berlin 14195 Germany School of Physics andAstronomy University of Manchester ManchesterM 13 9PL UK School of Chemistry University of Manchester Manchester M 13 9PL UK

We report the gate-modulated Raman spectrum of defective graphene. We show that the intensity of the D peak can be reversibly tuned by applying a gate voltage. This effect is attributed to chemical functionalization of the graphene crystal lattice, generated by an electrochemical reaction involving the water layer trapped at the interface between silicon and graphene.

关键词： graphene gating defects doping electrochemistry

Innovative Strengthening and Seismic Retrofitting of Concrete and Masonry Structures using Textile-based Composites

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Innovative Strengthening and Seismic Retrofitting of Concret...

Simulating Medical Imaging X-Ray Tubes with Various Parameters Using BEAMnrc Monte Carlo Software

第七届全国建设工程FRP应用学术交流会

作者： thanasis Triantafillou Department of Civil Engineering University of PatrasPatrasGreece

The author reviews experimental studies which have provided fundamental knowledge on the use of a new generation of composite materials,namely textile-reinforced mortars(TRM),as strengthening and seismic retrofitting materials of concrete and masonry *** are investigated as a means:to provide confinement in plain and reinforced concrete(RC),to increase the deformation capacity of old-type RC columns subjected to simulated seismic loading,to increase the shear and flexural resistance of RC members and to increase the out-of-plane or in-plane strength of unreinforced masonry *** all cases,the effectiveness of TRM systems is quantified through comparison with equivalent fiber-reinforced polymer(FRP) *** on the results it is concluded that TRM jacketing is an extremely promising new technique,which will enjoy the attention of the research community and will be employed in numerous applications in the next decades.

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Open Journal of Radiology 2022年第3期12卷 125-141页

作者： Nikolaos Chatzisavvas thanasis Koustas Georgios Karpetas Ioannis Valais Georgios Priniotakis Dimitrios Nikolopoulos Department of Industrial Design and Production Engineering University of West Attica Athens Greece Department of Medical Physics Medical School University of Patras Patra Greece Medical School University of Thessaly Larissa Greece Department of Biomedical Engineering University of West Attica Athens Greece

Context: Medical imaging has a wide range of applications in today’s society. Basic projectional radiography, CT scans, mammograms and a range of other advanced technologies all use x-rays to create a large number of examinations every day across the world. The most essential component of such medical equipment is the x-ray tube, which creates and produces x-rays. Objective: We describe and investigate an abstract model-geometry of a simple x-ray tube utilizing the open-source software package of BEAMnrc of the EGSnrcmp family, which is well validated by several studies over the years, for high and low energy photons generation. Methodology: Our research focuses on two different electron beam energies: 120 keV and 30 keV. The 120 keV is the typical energy for simple projectional radiographic exams and CT examinations, whereas the 30 keV is the typical energy of mammography. Results: Two different anode materials are used for each case, Gold (Au) and Tungsten (W) for 120 keV because these are the most common in projectional radiography and CT;Molybdenum (Mo) and Rhodium (Rh) for 30 keV because with these targets most mammography exams are carried out. The aim of this work is to show how the BEAMnrc software package can simulate effectively x-ray generation of low-energy photons which are utilized in modern medical imaging procedures. We describe useful information on anode-target characteristics, such as anode angle, anode material, and metal filter materials, based on previous quality studies even by using software other than BEAMnrc. Conclusion: We demonstrate that BEAMnrc can be efficiently used for Monte Carlo modeling of low-energy photons.

关键词： Bremsstrahlung Filter Monte Carlo Spectral Distribution X-Ray Tube

嵌入学习管理系统的基于词汇表的概念图应用程序

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开放教育研究 2005年第5期11卷 38-43页

作者： Giouvanakis thanasis Fragidis Garyfallos Paschaloudis Dimitrios Tarabanis Konstantinos 赵国庆 Technological Educational Institute of Serres Greece University of Macedonia Greece

概念构图作为一种有价值的教学活动,有着非常稳固的理论框架作为支持,其在教育教学中的作用不容置疑。本文介绍了一个软件工具的开发,在该工具中,概念构图被当作一种重要的教学活动予以支持。该工具以课程词汇表为基础,被集成到一个学... 详细信息

概念构图作为一种有价值的教学活动,有着非常稳固的理论框架作为支持,其在教育教学中的作用不容置疑。本文介绍了一个软件工具的开发,在该工具中,概念构图被当作一种重要的教学活动予以支持。该工具以课程词汇表为基础,被集成到一个学习管理系统中。该工具允许在词汇表中概念的详细描述和认知结构的知识表示之间切换。论文介绍了该应用程序的开发动机、合理性、特色及其应用。

关键词：概念构图知识表征学习教学词汇表

Scheduling Heuristics for Live Video Transcoding on Cloud Edges

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ZTE Communications 2017年第2期15卷 35-41页

作者： Panagiotis Oikonomou Maria G. Koziri Nikos Tziritas thanasis Loukopoulos XU Cheng-Zhong University of Thessaly Lamia 35100 Greece Research Center for Cloud Computing Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China

Efficient video delivery involves the transcoding of the original sequence into various resolutions,bitrates and standards,in order to match viewers’*** video coding and transcoding are computationally demanding,performing a portion of these tasks at the network edges promises to decrease both the workload and network traffic towards the data centers of media *** by the increasing popularity of live casting on social media platforms,in this paper we focus on the case of live video ***,we investigate scheduling heuristics that decide on which jobs should be assigned to an edge minidatacenter and which to a backend *** simulation experiments with different Qo S requirements we conclude on the best alternative.

关键词： video transcoding edge computing scheduling heuristics x264

A Connectivity-Based Legalization Scheme for Standard Cell Placement

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Circuits and Systems 2017年第8期8卷 191-201页

作者： Antonios N. Dadaliaris Panagiotis Oikonomou Maria G. Koziri Evangelia Nerantzaki thanasis Loukopoulos Georgios I. Stamoulis Department of Computer Science University of Thessaly Lamia Greece Department of Electrical and Computer Engineering University of Thessaly Volos Greece Department of Computer Science and Biomedical Informatics University of Thessaly Lamia Greece

Standard cell placement algorithms have been at the forefront of academic research concerning the physical design stages of VLSI design flows. The penultimate step of a standard cell placement procedure is legalization. In this step the manufacturability of the design is directly settled, and the quality of the solution, in terms of wirelength, congestion, timing and power consumption is indirectly defined. Since the heavy lifting regarding processing is performed by global placers, fast legalization solutions are protruded in state-of-the-art design flows. In this paper we propose and evaluate a legalization scheme that surpasses in execution speed two of the most widely used legalizers, without not only corrupting the quality of the final solution in terms of interconnection wirelength but improving it in the process.

关键词： Legalization Standard Cell Placement Heuristics Interconnect Wirelength

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多媒体学习研究的演进

远程教育杂志 2006年第6期24卷 22-29页

作者： Haido Samaras 张丽盛群力希腊马其顿大学浙江大学教育学院浙江杭州310028

在起源于教育领域之外的多媒体学习资源(像光盘和网络)大规模涌入之前,关于多媒体对学习的影响方面的实验研究已经有几十年的时间。尽管研究的结果并不是决定性的,但是前两代多媒体研究帮助我们确定了影响有效多媒体设计的要素。本文总... 详细信息

在起源于教育领域之外的多媒体学习资源(像光盘和网络)大规模涌入之前,关于多媒体对学习的影响方面的实验研究已经有几十年的时间。尽管研究的结果并不是决定性的,但是前两代多媒体研究帮助我们确定了影响有效多媒体设计的要素。本文总结了现有研究的结论,评述了每一代多媒体研究的主要理论问题、研究方向以及不足之处。论文还讨论了已经开始受到人们关注的第三代多媒体设计和学习研究新动向,也提出了若干表来发展趋势的建议。

关键词：多媒体学习技术多媒体学习环境认知学习研究