Shandong Computer Science Center National Supercomputer Center in Jinan

Jinan, China

Shandong Computer Science Center National Supercomputer Center in Jinan

Jinan, China
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Yang Y.,Soochow University of China | Guo M.,Shandong Computer Science Center National Supercomputer Center in Jinan | Zhang G.,Institute of High Performance Computing of Singapore | Li W.,Soochow University of China
Carbon | Year: 2017

We present a density-functional-theory study of the recently synthesized graphene-like carbon nitride monolayer (C2N) with transition metal atom (TM = Fe, Co and Ni) doping. We find that for three elements, the TM-C2N binding is strong and covalent in nature. While the pristine C2N is a semiconductor with non-magnetism at the ground state, the TM-C2N complexes exhibit metal characteristic and is spin-polarized. Particularly, a Fe atom on C2N can induce 3.91 μB magnetic moment with ferromagnetic coupling. For Co and Ni, smaller magnetic moment is observed with weaker coupling or even no coupling. The spin-polarization can be understood in the local-orbital picture, involving hybridizations of nitrogen's pz orbital with the 3d orbitals of metal. The work function of C2N can be effectively modulated by metal doping from 5.25 eV for pristine C2N to a range of 3.85–4.15 eV for doped ones. Our results indicate that the properties of C2N layer can be effectively modulated by chemical doping and the co-realization of metallic and ferromagnetic properties in doped C2N might find broad applications in the design of nanoscale electronic and spintronic devices. © 2017 Elsevier Ltd

Hao F.,Shandong Computer Science Center National Supercomputer Center in Jinan | Luo X.,Shandong Computer Science Center National Supercomputer Center in Jinan | Mu C.,Shandong Academy of Agricultural Sciences
Proceedings - 2016 International Conference on Smart City and Systems Engineering, ICSCSE 2016 | Year: 2016

The intelligent perception nodes for farmland environment information has the features of low cost and high efficiency, and with it the data in multiple crop growth cycle are available. Based on this, this paper, after making clear the relationship between farmland environmental factors and crop growth cycle and crop yield, aims at the establishment of environment-production model and building the system of crop growth environment perception and intelligent decision, in order to analyze agricultural data and give constructive advice about agricultural production, agricultural layout and agricultural scientific research. © 2016 IEEE.

Sun D.,Beihang University | Liu B.,Shandong Computer Science Center National Supercomputer Center in Jinan
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

With the development of new web technologies, the Massive Open Online Course (MOOC) which aims at unlimited participation and access is emerging. In contrast to traditional education, learners could get access to filmed lectures and tests online anytime and anywhere. However, there still exists some problems with MOOCs. Currently, one major problem is the imbalance between teachers and learners online. In many courses, thousands of learners enroll in a class with a single instructor which could lead to bad learning effect and very low completion rates, so we propose crowdsourcing based teaching assistant assignment for MOOC in order to optimize the reasonable disposal of manpower. We present effective algorithms for the selection and assignment of teaching assistants. With experiments on various datasets, we verify the effectiveness of our proposed methods. © Springer International Publishing AG 2017.

Wang Z.,Qingdao University | Wang Z.,Kyushu University | Bauch C.T.,University of Waterloo | Bhattacharyya S.,Shiv Nadar University | And 6 more authors.
Physics Reports | Year: 2016

Historically, infectious diseases caused considerable damage to human societies, and they continue to do so today. To help reduce their impact, mathematical models of disease transmission have been studied to help understand disease dynamics and inform prevention strategies. Vaccination–one of the most important preventive measures of modern times–is of great interest both theoretically and empirically. And in contrast to traditional approaches, recent research increasingly explores the pivotal implications of individual behavior and heterogeneous contact patterns in populations. Our report reviews the developmental arc of theoretical epidemiology with emphasis on vaccination, as it led from classical models assuming homogeneously mixing (mean-field) populations and ignoring human behavior, to recent models that account for behavioral feedback and/or population spatial/social structure. Many of the methods used originated in statistical physics, such as lattice and network models, and their associated analytical frameworks. Similarly, the feedback loop between vaccinating behavior and disease propagation forms a coupled nonlinear system with analogs in physics. We also review the new paradigm of digital epidemiology, wherein sources of digital data such as online social media are mined for high-resolution information on epidemiologically relevant individual behavior. Armed with the tools and concepts of statistical physics, and further assisted by new sources of digital data, models that capture nonlinear interactions between behavior and disease dynamics offer a novel way of modeling real-world phenomena, and can help improve health outcomes. We conclude the review by discussing open problems in the field and promising directions for future research. © 2016 Elsevier B.V.

Long R.,Beijing Normal University | Guo M.,Shandong Computer Science Center National Supercomputer Center in Jinan | Liu L.,Beijing Normal University | Fang W.,Beijing Normal University
Journal of Physical Chemistry Letters | Year: 2016

Black phosphorus (BP) is an appealing material for applications in electronics and optoelectronics because of its tunable direct band gap and high charge carrier mobility. For real optoelectronic device utilization, nonradiative electron-hole recombination should be slow because it constitutes a major pathway for charge and energy losses. Using time-domain density functional theory combined with nonadiabatic (NA) molecular dynamics, we show that nonradiative electron-hole recombination occurs within several tens of picoseconds in bilayer BP, agreeing well with experimental data. When a single layer of BP is stacked with monolayer MoS2, the recombination is reduced because of the increased band gap and reduced electron-phonon NA coupling compared to bilayer BP. The slow electron-phonon energy losses in BP-MoS2 van der Waals heterojunction relative to bilayer BP indicate that rationally stacking BP with other two-dimensional materials is an attractive route for designing novel and efficient photovoltaic materials. © 2016 American Chemical Society.

Fu Y.,Shandong Computer Science Center National Supercomputer Center in Jinan
International Journal of Distributed Sensor Networks | Year: 2017

This article presents an anchor node based on directional antenna array and reports the design of an automatic test system. The antenna radiation characteristics and the wireless channel model are studied first, followed by the evaluation of a single anchor node localization algorithm for wireless sensor network real-time positioning on the base of antenna radiation modeling and radio channel propagation model research then. Finally, the algorithm is evaluated by experiments in real environments. Experimental results show that the algorithm positioning accuracy could reach 1 m, and angular positioning accuracy error is less than 20º with no data exchange required during the positioning process. Hence, the wireless data transmission protocol complexity is reduced with improved real-time performance. This study is expected to provide technical references for the method research of wireless sensor network real-time positioning and new positioning system in practical applications. © The Author(s) 2017.

Hao F.,Shandong Computer Science Center National Supercomputer Center in Jinan | Zhao X.,Qingdao Technological University | Wang M.,Shandong Computer Science Center National Supercomputer Center in Jinan
Advances in Intelligent Systems and Computing | Year: 2018

Combining the advanced arm architecture and embedded Linux operating system and equipment running information test and diagnosis technology, the power of the embedded Linux intelligent agricultural machinery equipment condition monitoring system was designed and developed. The whole monitoring system is divided into two parts, the foreground and the background. 3S technology as the core of the research and development of digital agriculture spatial information management platform is a breakthrough in digital agriculture research. In recent years, supported by agricultural research information management system development has laid a good foundation. Front desk is mainly used for data collection and simple data analysis, these data for monitoring the status of the agricultural, including information, position information, state of the engine, torque converter oil temperature, brake system pressure, transmission oil temperature etc. Background to provide a powerful data processing function, used to collect the data for further analysis and processing. And these data of an effective combination of cloud technology achieve the command and dispatch of agricultural machinery and effectively achieve the monitoring of equipment operating conditions, with obvious practical and engineering application value. © 2018, Springer International Publishing AG.

Cheng G.H.,Shandong Computer Science Center National Supercomputer Center in Jinan | Sun R.R.,Shandong University of Technology
Advanced Materials Research | Year: 2014

Due to construction projects testing requirements work continuously for more than a week or even a month or so, so for a battery-powered portable heat and temperature acquisition system, its power consumption has the constraints. In accordance with the need of the acquisition system of actual engineering, this paper from two aspects of hardware and software to consider heat flux and temperature acquisition system of low power design, specific design ideas and implementation methods is also given in this paper. The test results demonstrate that the sleep state, the actual operating current is 0.59mA. A nominal 1000mAh lithium battery, the case of the sleep wake of five minutes, can work continuously for about 20 days, the case of 10 minutes to wake up dormant, can work continuously for about a month. © (2014) Trans Tech Publications, Switzerland.

Zhao D.,Shandong Computer Science Center National Supercomputer Center in Jinan | Wang L.,Shandong Computer Science Center National Supercomputer Center in Jinan | Li S.,Shandong Institute of Business and Technology | Li S.,National University of Defense Technology | And 3 more authors.
PLoS ONE | Year: 2014

Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks. Copyright: © 2014 Zhao et al.

Ge L.,Shandong Computer Science Center National Supercomputer Center in Jinan | Wang L.,Shandong Computer Science Center National Supercomputer Center in Jinan
Communications in Computer and Information Science | Year: 2015

The forensics for the iPhone backup files is an important problem in digital forensics. Since the backup files are often encrypted and the key chain data is always encrypted even if the data is not completely encrypted, it is difficult to deal with this problem by the traditional methods such as sequence brute force. In this paper, we give a new method based on parallel random search on CPU+GPU platform to solve this problem. The main principle of this method is to parallel random search the passwords in the given dictionary based on the CPU+GPU platform in order to crack the password of the encrypted iPhone backup files. An analysis of decryption and reduction method as well as the file structure is also shown in this paper. Finally the experiment result shows that the method given in this paper can greatly improve the efficiency of forensics for the encrypted iPhone backup files. © Springer-Verlag Berlin Heidelberg 2015.

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