Person-Dependent Handwriting Verification for Special Education Using DeepLearning

Individuals with special needs learn more slowly than their peers and they need repetitions to be permanent.However,in crowded classrooms,it is dif-ficult for a teacher to deal with each student individually.This problem can be overcome by using supportive education applications.However,the majority of such applications are not designed for special education and therefore they are not efficient as expected.Special education students differ from their peers in terms of their development,characteristics,and educational qualifications.The handwriting skills of individuals with special needs are lower than their peers.This makes the task of Handwriting Recognition(HWR)more difficult.To over-come this problem,we propose a new personalized handwriting verification sys-tem that validates digits from the handwriting of special education students.The system uses a Convolutional Neural Network(CNN)created and trained from scratch.The data set used is obtained by collecting the handwriting of the students with the help of a tablet.A special education center is visited and the handwrittenfigures of the students are collected under the supervision of special education tea-chers.The system is designed as a person-dependent system as every student has their writing style.Overall,the system achieves promising results,reaching a recognition accuracy of about 94%.Overall,the system can verify special educa-tion students’handwriting digits with high accuracy and is ready to integrate with a mobile application that is designed to teach digits to special education students.

Processes of DNA condensation induced by multivalent cations: Approximate annealing experiments and molecular dynamics simulations

The condensation of DNA induced by spermine is studied by atomic force microscopy （AFM） and molecular dynamics （MD） simulation in this paper. In our experiments, an equivalent amount of multivalent cations is added to the DNA solutions in different numbers of steps, and we find that the process of DNA condensation strongly depends on the speed of adding cations. That is, the slower the spermine cations are added, the slower the DNA aggregates. The MD and steered molecular dynamics （SMD） simulation results agree well with the experimental results, and the simulation data also show that the more steps of adding multivalent cations there are, the more compact the condensed DNA structure will be. This investigation can help us to control DNA condensation and understand the complicated structures of DNA--cation complexes.

Decondensation behavior of DNA chains induced by multivalent cations at high salt concentrations:Molecular dynamics simulations and experiments

Using molecular dynamics simulations and atomic force microscopy （AFM）, we study the decondensation process of DNA chains induced by multivalent cations at high salt concentrations in the presence of short cationic chains in solutions. The typical simulation conformations of DNA chains with varying salt concentrations for multivalent cations imply that the concentration of salt cations and the valence of multivalent cations have a strong influence on the process of DNA decondensation. The DNA chains are condensed in the absence of salt or at low salt concentrations, and the compacted conformations of DNA chains become loose when a number of cations and anions are added into the solution. It is explicitly demonstrated that cations can overcompensate the bare charge of the DNA chains and weaken the attraction interactions between the DNA chains and short cationic chains at high salt concentrations. The condensation-decondensation transi- tions of DNA are also experimentally observed in mixing spermidine with X-phage DNA at different concentrations of NaCl/MgCl2 solutions.

Large eddy simulation of high-Reynolds-number atmospheric boundary layer flow with improved near-wall correction

It is highly attractive to develop an efficient and flexible large eddy simulation(LES)technique for high-Reynolds-number atmospheric boundary layer(ABL)simulation using the low-order numerical scheme on a relatively coarse grid,that could reproduce the logarithmic profile of the mean velocity and some key features of large-scale coherent structures in the outer layer.In this study,an improved near-wall correction scheme for the vertical gradient of the resolved streamwise velocity in the strain-rate tensor is proposed to calculate the eddy viscosity coefficient in the subgrid-scale(SGS)model.The LES code is realized with a second-order finite-difference scheme,the scale-dependent dynamic SGS stress model,the equilibrium wall stress model,and the proposed correction scheme.Very-high-Reynolds-number ABL flow simulation under the neutral stratification condition is conducted to assess the performance of the method in predicting the mean and fluctuating characteristics of the rough-wall turbulence.It is found that the logarithmic profile of the mean streamwise velocity and some key features of large-scale coherent structures can be reasonably predicted by adopting the proposed correction method and the low-order numerical scheme.

Ground motion record simulation for structural analysis by consideration of spectral acceleration autocorrelation pattern

A novel approach is introduced to generate simulated ground motion records by considering spectral acceleration correlations at multiple periods. Most of the current reliable Ground Motion Record(GMR) simulation procedures use a seismological model including source, path and site characteristics. However, the response spectrum of simulated GMR is somewhat different when compared with the response spectrum based on recorded GMRs. More specifi cally, the correlation between the spectral values at multiple periods is a characteristic of a record which is usually different between simulated and recorded GMRs. As this correlation has a signifi cant infl uence on the structural response, it is needed to investigate the consistency of the simulated ground motions with actual records. This issue has been investigated in this study by incorporating an optimization algorithm within the Boore simulation technique. Eight seismological key parameters were optimized in order to achieve approximately the same correlation coeffi cients and spectral acceleration between two sets of real and simulated records. The results show that the acceleration response spectra of the synthetic ground motions also have good agreement with the real recorded response spectra by implementation of the proposed optimized values.

Rice yield estimation using remote sensing and simulation model

Remote sensing techniques have the potential to provide information on agricultural crops quantitstively,instantaneously and above all nondestrctively over large areas.Crop simulation models describe the relationship between physiological process in plants and environmental growing conditions.The integration between remote sensing data and crop growth simulation model is an important trent for yield estirmation and prediction,since remote sensing can provide information on the actual status of the agricultural crop.In this study,a new model(Rice-SRS) was developed based mainly on ORYZA1 model and modified to accept remote sensing data as input from different sources.The modelc an accept three kinds of NDVI,data.NOAA AVHRR(LAC)-NDVI,NOAA AVHRR(GAC)-NDVI and radiometric measurements-HDVI,The integration between NOAA AVHRR(LAC) data and simulation model as applied to Rice-SPS resulted in accurate estimates for rice yield in the Shaoxing area.reduced the estimating error to 1.027%,0.794% and (-0.787%) for early,single,and late season repectively.Utilizing NDVI data derived from NOAA AVHRR(GAC) as input in Rice-SRS can yield good estimation for rice yield with the average error (-7.43%) .Testing the new model for radiometric meassurements showed that the average estimation error for 10 varieties under early rice conditions was less than 1%.

台风-浪-流耦合作用超大浮体水弹性响应分析方法

海上机场超大浮体结构在台风等极端海洋环境下的动态响应准确预测是保障其安全性能的关键前提,其难点在于准确构建中/小尺度复杂流场与浮体结构的流固耦合计算模型。本文提出了一种基于中/小尺度嵌套的海上机场超大浮体水弹性响应分析方法,二次开发实现了台风-浪-流耦合模拟,分析了超强台风“莫兰蒂”途经海上机场超大浮体全过程台风-浪-流时空演变规律;采用中/小尺度流场嵌套技术计算水动力和气动力,代入结构动力学方程进行双向迭代解耦求解;通过算例分析了台风-浪-流耦合作用下浮体结构水弹性响应及影响机制。研究表明:本文提出的方法能够有效地预测此类极端环境下超大浮体结构水弹性响应。

特高压GIS用磁环型阻尼母线VFTO抑制性能试验研究

GIS中的隔离开关在操作过程中由于断口重复击穿会产生特快速瞬态过电压(very fast transient overvoltage,VFTO)。VFTO幅值高、波前陡,严重威胁电气一次绝缘,并会产生电磁干扰问题。目前,实际工程中除采用带投切电阻的隔离开关抑制VFTO外,还可以采用磁环型阻尼母线对VFTO进行抑制。为了保证GIS的可靠性,磁环型阻尼母线抑制性能的优劣至关重要。为此,亟需研究提出一种在试验室进行磁环抑制效果的评定方法。文中针对磁环型阻尼母线的抑制性能,设计了专门的抑制性能试验回路,该试验回路中主要包含套管、阻尼电阻、放电间隙、磁环型阻尼母线、GIS短母线、VFTO传感器以及VFTO测量系统。该试验回路的额定电压为1100 kV,回路中的套管和母线可承受的额定工频电压为1100 kV,阻尼电阻的阻值为560Ω或1500Ω,放电间隙可以通过电极间距的调整产生不同等级的放电电压值和放电陡波,陡波上升时间可以达到30 ns。应用该试验回路在试验室进行模拟试验的方法检验磁环型阻尼母线的抑制效果,试验结果表明,该试验回路可以完成磁环型阻尼母线抑制效果的检验,可以定量地给出抑制效果的优劣。该方法可以推广到其他电压等级的GIS产品中,有助于推动实现磁环型阻尼母线的工业化设计、制造及检验。

充气式平底旋流器流场数值模拟研究

为提高旋流器的分离精度和效率,设计了一种充气式平底旋流器,并采用CFD数值模拟技术探究其内部流场规律。研究结果表明:充气式旋流器外旋流附近的压力梯度高于平底旋流器,切向充气式旋流器更加明显;充气式旋流器的切向速度在半径10 mm以外区域高于平底旋流器,切向充气式旋流器更明显;在内旋流区域中心,充气式旋流器的轴向速度较大,切向充气式旋流器的变化更为明显,充气式旋流器在外旋流区域的轴向速度小于平底旋流器;对于粗颗粒来说,切向充气式旋流器的分级效率最高,对于细颗粒来说,径向充气式旋流器的分级效率最高;研究结果可为充气式旋流器的设计及应用提供经验借鉴。

Multi-objective optimization of high-sulfur natural gas purif ication plant

There exists large space to save energy of high-sulfur natural gas purification process.The multi-objective optimization problem has been investigated to effectively reduce the total comprehensive energy consumption and further improve the production rate of purified gas.A steady-state simulation model of high-sulfur natural gas purification process has been set up by using ProMax.Seven key operating parameters of the purification process have been determined based on the analysis of comprehensive energy consumption distribution.To solve the problem that the process model does not converge in some conditions,back-propagation(BP)neural network has been applied to substitute the simulation model to predict the relative parameters in the optimization model.The uniform design method and the table U21(107)have been applied to design the experiment points for training and testing BP model.High prediction accuracy can be achieved by using the BP model.Nondominated sorting genetic algorithm-II has been developed to optimize the two objectives,and 100 Pareto optimal solutions have been obtained.Three optimal points have been selected and evaluated further.The results demonstrate that the total comprehensive energy consumption is reduced by 13.4%and the production rate of purified gas is improved by 0.2%under the optimized operating conditions.

Calculation of all-time apparent resistivity of large loop transient electromagnetic method with very fast simulated annealing

In large loop transient electromagnetic method(TEM),the late time apparent resistivity formula cannot truly reflect the geoelectric model,thus it needs to define the all-time apparent resistivity with the position information of measuring point.Utilizing very fast simulated annealing(VFSA) to fit the theoretical electromagnetic force(EMF) and measured EMF could obtain the all-time apparent resistivity of the measuring points in rectangular transmitting loop.The selective cope of initial model of VFSA could be confirmed by taking the late time apparent resistivity of transient electromagnetic method as the prior information.For verifying the correctness,the all-time apparent resistivities of the geoelectric models were calculated by VFSA and dichotomy,respectively.The results indicate that the relative differences of apparent resistivities calculated by these two methods are within 3%.The change of measuring point position has little influence on the tracing pattern of all-time apparent resistivity.The first branch of the curve of all-time apparent resistivity is close to the resistivity of the first layer medium and the last branch is close to the resistivity of the last layer medium,which proves the correctness of the arithmetics proposed.

极缓坡黄土坡面片状侵蚀及其水动力学参数特征

随着黄土高原生态文明建设的持续开展,极缓坡耕地成为当地受生产活动影响最显著的区域,其土壤侵蚀规律应得到关注。基于此,采用室内模拟降雨试验,在90 mm/h雨强、两种坡度(2.5°和5°)和两种坡长(5 m和10 m)情况下,对两种土壤(安塞土和绥德土)的片状侵蚀特征及水动力学参数的变化规律进行了研究。结果表明:与安塞土相比,绥德土的产流和径流增加速度快,有较高径流率和含沙量,且易发生细沟。安塞土在径流稳定前的平均径流率和含沙量的变化范围分别为2.76~8.61 L/min和0.80~9.26 g/L,径流稳定后两者的变化范围分别为3.76~11.69 L/min和0.46~2.88 g/L;绥德土径流稳定前后平均径流率和含沙量的范围分别为3.94~12.75 L/min、2.13~10.64 g/L和4.51~15.02 L/min、1.20~4.51 g/L。两种土壤的含沙量与径流率的关系可以用线性递减函数和含沙量作为常数两种线性关系进行表征。雷诺数和径流功率与径流率呈明显稳定的线性递增函数关系;径流流速和弗劳德数随径流率增加有较明显的增加趋势,但波动性较大;径流剪切力随径流率变化表现出很大的离散性。总体上对于片蚀,雷诺数和径流功率是最能用以表征土壤侵蚀的水动力学参数,其次是径流流速和弗劳德数,再者是径流剪切力。研究结果可为优化土壤侵蚀模型参数提供理论参考。

水翼端部间隙泄漏流的压降及黏性损失机理

叶顶泄漏流产生的局部压降及黏性损失是导致轴流式水力机械效率下降和轮缘间隙空化的主要原因.为探明间隙泄漏流的黏性损失特性和低压形成机制,以NACA0009水翼为对象,采用超大涡模拟方法(VLES)对翼端间隙流动进行数值模拟,基于平均流动动能转换与输运分析,提出了间隙区黏性损失定量计算模型,研究了翼端间隙区湍动能生成、黏性损失和压降的产生机理及主要影响因素.结果表明,间隙区存在间隙分离涡(TSV)、间隙泄漏涡(TLV)和诱导涡(IV)等流动结构;湍动能生成是导致TSV内压降的主导因素,TLV内压降则主要受湍动能生成和平均动能的对流和扩散效应影响;湍动能耗散导致的翼端区域黏性损失占间隙区黏性损失总量的91.2%.间隙区不同流动结构对湍动能生成的影响存在明显差异,水翼吸力面的强剪切效应主要生成湍动能的■分量,而TLV,TSV和IV等间隙涡结构则主要生成湍动能的■和■分量;湍动能产生机制分析表明,湍动能生成项分量Pvw是TLV和TSV中湍动能生成的主导因素,减小TSV和TLV内的速度梯度■,可有效降低湍动能生成,进而减少翼端区域因湍流耗散导致的黏性损失.研究结果可为间隙流动控制提供参考.

基于超大涡模拟的燃烧室气动性能仿真研究进展

航空发动机燃烧室涉及旋流、雾化蒸发、掺混、化学反应、湍流与火焰相互作用等多尺度强耦合物理化学过程,相关的高精度建模和数值模拟面临极大的挑战。超大涡模拟是近些年发展的兼顾计算精度、计算效率和强鲁棒性的数值模拟新方法,具备试验室尺度和复杂工程应用场景下湍流流动与燃烧仿真能力。针对航空发动机燃烧室相关流动与燃烧基本特征,阐述了超大涡模拟的理论方法及特点,从旋流流动、湍流燃烧、液雾雾化、碳烟生成、燃烧不稳定等典型多物理过程,以及双旋流模型燃烧室和高温升燃烧室气动性能集成仿真等方面介绍了超大涡模拟的研究进展,对涉及的物理机制进行了分析,为超大涡模拟在航空发动机燃烧室中规模化工程应用提供了坚实支撑。超大涡模拟在较低的计算资源消耗下具备与传统大涡模拟相当的计算精度,是一种经济可承受的燃烧室高精度气动性能仿真新方法。

Cloning and Functional Validation of Mung Bean VrPR Gene

For the purpose of functional validation,the mung bean(Vigna radiata)VrPR gene was cloned and overexpressed in Arabidopsis thaliana.Thefindings revealed that the ORF of VrPR contained 1200 bp,in which 399 amino acids were encoded.Bioinformatics analysis showed that the VrPR protein belonged to the NADB Rossmann superfamily,which was one of the non-transmembrane hydrophilic proteins.VrPR was assumed to have 44 amino acid phosphorylation sites and be contained in chloroplasts.The VrPR secondary structure comprised of random coil,αhelix,βangle,and extended chain,all of which were quite compatible with the anticipated tertiary structure.Moreover,analysis of the phylogenetic tree indicated that the soybean PR(Glyma.12G222200)and VrPR were closely related.Furthermore,chlorophyll content in leaves is markedly increased in Arabidopsis when VrPR is overexpressed.Ourfindings will serve as a reference for more functional studies on the PR genes in mung bean.

Multi Attribute Case Based Privacy-preserving for Healthcare Transactional Data Using Cryptography

Medical data mining has become an essential task in healthcare sector to secure the personal and medical data of patients using privacy policy.In this background,several authentication and accessibility issues emerge with an inten-tion to protect the sensitive details of the patients over getting published in open domain.To solve this problem,Multi Attribute Case based Privacy Preservation(MACPP)technique is proposed in this study to enhance the security of privacy-preserving data.Private information can be any attribute information which is categorized as sensitive logs in a patient’s records.The semantic relation between transactional patient records and access rights is estimated based on the mean average value to distinguish sensitive and non-sensitive information.In addition to this,crypto hidden policy is also applied here to encrypt the sensitive data through symmetric standard key log verification that protects the personalized sensitive information.Further,linear integrity verification provides authentication rights to verify the data,improves the performance of privacy preserving techni-que against intruders and assures high security in healthcare setting.

Electro-chemo-mechanical design of polymer matrix in composited LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode endows solid-state batteries with superior performance

Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathode material has been widely concerned due to its high voltage,high specific capacity and excellent rate performance,which is considered as one of the most promising cathode materials for the next generation of high-energy-density solid-state lithium batteries.However,serious electro-chemo-mechanical degradation of Nickel-rich cathode during cycling,especially at a high voltage(over 4.5 V),constrains their large-scale application.Here,using the multiphysical simulation,highly-conductive polymer matrix with spontaneous stress-buffering effect was uncovered theoretically for reinforcing the electrochemical performance of composited NCM81 1 cathode through the visualization of uniform concentration distribution of Li-ion coupled with improved stress field inside NCM811 cathode.Thereupon,polyacrylonitrile(PAN) and soft polyvinylidene fluoride(PVDF) were selected as the polymer matrix to fabricate the composited NCM811 cathode(PVDFPAN@NCM811) for improving the electrochemical performance of the solid-state NMC811|Li full cells,which can maintain high capacity over 146.2 mA h g^(-1)after 200 cycles at a high voltage of 4.5 V.Suggestively,designing a multifunctional polymer matrix with high ionic conductivity and mechanical property can buffer the stress and maintain the integrity of the structure,which can be regarded as the door-opening avenue to realize the high electrochemical performance of Ni-rich cathode for solidstate batteries.

不同过冷度条件下HCP-Mg凝固过程中的空位捕获

采用不同的分子动力学(molecular dynamics, MD)技术模拟了密排六方(hexagonal close-packed, HCP)金属Mg在深、中、浅过冷度条件下的凝固及退火过程,并利用新建的时间平均原子体积谱(time-averaged atomic volume spectrum, TAVS)方法对空位进行了标定分析.结果表明:凝固过程中的空位捕获效应非常明显,即过冷度越大,捕获空位的浓度就越高,且远高于对应的平衡空位浓度.同时发现, HCP-Mg在凝固过程中存在一定量的自间隙原子.这与对称性更高的面心立方(face-centered cubic, FCC)金属Al完全不同.此外,HCP-Mg的空位原子(vacancy atoms, VA)笼存在外扩位移,而不是目前普遍公认的金属空位原子的内缩位移.

水自由基阳离子化学的研究进展

对水自由基阳离子及其团簇离子((H_(2)O)_(n)^(+·))反应的研究可更好地理解某些自然过程的机制,如水溶液中的质子转移、氢键形成、DNA等生物大分子的破坏以及发现新的气相反应和产物.此外,(H_(2)O)_(n)^(+·)在放射生物学中以及作为初级反应离子在选择性电离和提高分析灵敏度等分析领域均具有广阔的应用前景.目前,质子化水团簇和水合电子成键及结构研究较多,但对具有超高的反应活性和极短寿命的(H_(2)O)_(n)^(+·)的分离和理化性质研究较少.近期,质谱技术、分子光谱-质谱联合技术和高精度量子化学理论计算发展迅速,基于此综述有关(H_(2)O)_(n)^(+·)的形成方法与产生机制、结构理论模拟与实验验证、化学性质分析以及应用研究等方面的进展.