Research on Real-time Abnormal Detection of Network Traffic under The Big Data Environment

随着互联网的快速发展，数据网规模不断扩大，基于数据网的各种应用业务也越来越广泛，对各大运营商以及业务数据量大的企业，在运维管理方面不得不投入了大量的人力与物力。在运维管理中，故障实时预警是最重要的一部分，快速并准确地预警故障，可以以最快的速度发现业务环境中的问题，从而及时地避免故障带来的严重损失。在大数据环境下，研究实时故障预警技术的理论和实现机制，在现实运维管理中有很大的实际意义。 其中流量实时预警是最重要的一个环节，通过流量的实时预警，可以很大程度反馈业务的故障。因此，本文的研究重点主要是针对流量序列的异常检测展开。 本文的研究内容主要包含两个部分：流量异常检测的准确性和在大数据环境下...With the rapid development of Internet, the data network scale expands unceas-ingly, on the basis of data network business is becoming more and more widely ap-plied, the operators and enterprises, business data in operational management had to spend a lot of manpower and material resources. In operations management, real-time fault early warning is one of the most important part of early warning a...学位：工学硕士院系专业：软件学院_计算机软件与理论学号：2432011115228

A Study on Tax Source Management Based on The Idea of Information-based Tax Administration

税源管理是税收管理的基础，是决定税收征管水平的重要方面。税源管理的水平直接决定着征管质量水平，只有强化税源管理，才能不断提高征管效能，堵塞征管漏洞，减少税收流失的风险。随着我国税收信息化水平的提高和经济飞速发展，税收管理环境发生急剧变化，我国适时地把“信息管税”作为指导今后税收征管工作的指导思想。这一思路的提出，必然挑战现行的税收管理框架，所以，在新思路指导下的税源管理也必须做出调整，才能适应税收征管指导思想的转变。因此，研究基于信息管税思路的税源管理有着非常强的现实指导意义。 本文首先运用系统分析的方法对税源管理的各个方面所受到的“信息管税”思路的冲击进行分析，接着运用比较分析的方法将国外...Tax source management is the foundation of tax revenue administration and an important aspect which determines the level of tax revenue collection and administration. The level of tax source management decides the level of tax revenue collection and management directly. Only by strengthening the tax source management, can we improve the efficiency and tighten the loophole of tax revenue collection...学位：经济学硕士院系专业：经济学院财政系_财政学(含税收学)学号：1552009115157

Parametric optimum design of an irreversible photon-enhanced thermionic emission solar cell hybrid system

考虑实际系统中存在的多种传热损失,本文建立一类不可逆光子增强热离子发射太阳能电池与温差热电发电器组合而成的混发电系统模型.基于太阳能电池与温差热电发电器之间的能量平衡方程,导出该混合系统输出功率和效率的表达式.通过数值计算,详细分析了光增热离子太阳能电池的面积、阴极半导体材料的禁带宽度、电子亲和势以及温差热电发电器的无量纲电流对混合系统优化性能的影响,确定混合发电系统运行于最大效率下光子增强热离子太阳能电池阴极材料的禁带宽度,电子亲和势,电池面积和温差热电发电器的无量纲电流的优化值.结果表明,采用混合发电系统,太阳能转换效率与工作于相同条件下的单一光增热离子太阳能电池的效率相比可提高约10%,而光增热离子太阳能电池阴极半导体材料禁带宽度在最大效率下的优化值则比单一光增热离子太阳能电池的小.本文所得结果可为实际光子增强热离子太阳能电池混合发电系统的设计和优化运行提供理论依据.A class of an irreversible thermodynamic model of the hybrid power system consisting of a photon-enhanced thermiomic emission solar cell(PETSC) and a thermoelectric generator(TEG) is established, in which some main irreversible losses existing real hybrid systems are taken into account. Based on equations of the energy balance between the solar cell and thermoelectric generator,expressions for the power output and efficiency of the hybrid system are derived. By using the numerical calculation, influences of the cell area, the energy band gap and electron affinity of the cathode semiconductor materials, and the dimensionless current of the generator on the optimal performance of the hybrid system are analyzed in detail. Under the operating condition of maximum efficiency, the optimal values of some important performance parameters of the hybrid system, such as the energy band gap, electron affinity, area and dimensionless current, are given. The results obtained in this paper show that by using the hybrid system, the solar energy conversion efficiency can be increased by about 10% and the optimal value of the energy band gap for the PESTC of the hybrid system at maximum efficiency is smaller than that of the energy band gap for alone operating PESTC. All the results obtained in this article will provide some theoretical basis for the design and optimal operation of practical PETSC hybrid system.国家自然科学基金(批准号:11175148,11305064);; 福建省自然科学基金(批准号:2011J01012);; 华侨大学引进人才科研启动资金(编号:09BS510)资助项

鲁米诺电致化学发光机理的研究

The electrochemiluminescence (ECL) of the luminol in aqueous alkaline solu tion has been studied using cyclic voltammetry, potential step tecdrique and time resolved UV/Vis spectroscopy. The results of the electrochemical experimens showed that the ECL of the luminol can carry out in the potential region of oxygen adsorption also and lead us suggest a new light-endtting pathway for the bonol on which the reaction between some of the luminol radical Anons and the adsorbed superokide radical sndtaneously gener ated in the anodic oxidation process yields excited 3-drinophthalate, the light emitting species. The results of the time resolved spectroscopic experiments manifested that the formation of the polymeric film produced by the luminol radical anions is one of important faetors decreasing the ECL of the luminol

Comparison of Two Axisymmetrical Finite Element Models for Pulsed Eddy Current Simulation

脉冲涡流检测技术是近年来发展迅速的一种新型涡流检测技术。由于其激励信号频谱宽广,不同频率分量的涡流能够渗透到不同深度,使其检测信号包含更丰富的深度方向的缺陷信息,在航空维修等工业领域有着重要的意义。对脉冲涡流检测的仿真可以指导脉冲涡流检测技术的研究。本文利用二维轴对称模型,介绍了脉冲涡流有限元仿真的两种方法—傅里叶变换法和时间步进法,并详细比较了这两种方法的优缺点。Pulsed eddy current testing(PECT) is one of the new techniques of eddy current testing.Thanks to the large amount of frequency components,the response signal contains rich information about defect and material properties along the depth direction.Therefore the PECT plays a significant role in the maintenance of aircrafts,nuclear power plants and so on.This paper introduces the two main methods used in the finite element modeling of PECT.Comparison of the methods is given.航空科学基金项目资助(批准号:2009ZD68004

Investigation on the iodine status among the population in rural and urban areas of Xiamen in 2013

目的了解碘盐新标准实施后农村和城市人群的碘营养现况,为有效落实科学补碘防控策略提供依据。方法在农村和城市调查点各抽取1个镇的1个村,在每个村采集自来水厂出厂水和末梢水各2份;抽取30户以上居民,采集各户家庭食用盐,用3日称量法测算各户居民人均食盐摄入量;抽取18-45岁成人50名以上,采集尿样。在抽中的镇随机选择8-10岁儿童(男女各半)、孕妇和哺乳期妇女各50名以上,采集尿样。测定盐碘、尿碘和水碘含量。结果农村和城市自来水末梢水水碘含量均值分别为4.5μg/L和6.0μg/L;居民人均每日食用盐摄入量中位数分别为7.0和5.6g;8~10岁儿童尿碘中位数分别为152.0和181.2μg/L;哺乳妇尿碘中位数分别为108.3和107.7μg/L;18-45岁成人尿碘中位数分别为121.1和147.4μg/L;孕妇尿碘中位数分别为116.0和112.2μg/L,尿碘含量低于150μg/L的比例分别达67.9%和64%;除农村人均每日食用盐摄入量高于城市,农村18-45岁成人尿碘水平低于城市外,其他指标农村和城市间差异无显著性。结论厦门市仍是缺碘地区,在现有碘盐标准下,8-10岁儿童、18-45岁成人、哺乳期妇女的碘营养处于适宜水平,但孕妇的碘营养不足,要开展针对孕期人群的碘营养监测和指导,杜绝碘缺乏所造成的危害。Objective To gain knowledge of the iodine status among the population in rural and urban areas after the implement of new standard for edible salt and to provide scientific evidence for the initiative of the iodine supplement strategy. Method 1 village / community was selected randomly from rural and urban area as research site respectively. 2 samples of treated water and tap water were collected respectively in both sites, 30 + houses were enrolled randomly and edible salt samples were collected. 3days weighed record was employed to estimate average salt daily intake. Urine sample was collected from 50 + adults aged from 18 to 45. Identical sample was also collected from 50 + children aged from 8 to 10( same amount of subjects in both genders),pregnant women, and lactating women respectively. Iodine level of water, salt, and urine was determined by laboratory assay.Results The iodine concentration of tap water in rural and urban areas was 4. 5 μg / L and 6. 0 μg / L,respectively. The median of average iodine intake in rural and urban areas was 7. 0 g and 5. 6 g, respectively. The median in urine iodine was 152. 0 μg / L and 181. 2 μg / L,respectively. This measurement in lactating women was 108. 3 μg / L and 107. 7 μg / L,respectively. And it was121. 1 μg / L and 147. 4 μg / L in adults aged 18 to 45, respectively. As for the pregnant women, the iodine level reached 116. 0μg /L and 112. 2 μg /L,respectively. The proportion of subjects has urine iodine level less than 150 μg /L reached 67. 9 % and 64 %, respectively. The average salt intake in rural area was higher than urban significantly, and the urine iodine level in adults aged 18 to 45 from rural area was significantly lower than urban. No significance was found in other comparison. Conclusion Through our investigation,Xiamen is still an iodine deficiency area. Under the implement of new edible salt standard, the iodine status in children aged 8 to 10, adults aged 18 to 45 and lactating women was adequate, however, we found that pregnant women enrolled in our study have iodine deficiency in some degrees. Therefore the iodine surveillance and dietary guidance should be performed among pregnant women to eliminate the harm caused by iodine deficiency

Selective dynamical imaging of interferometric data

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT’s (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data sethttp://iopscience.iop.org/2041-8205Physic

First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring

In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow

First Sagittarius A* Event Horizon Telescope results. II. EHT and multiwavelength observations, data processing, and calibration

We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5–11 campaign. The observations were carried out with eight facilities at six locations across the globe. Novel calibration methods are employed to account for Sgr A*'s flux variability. The majority of the 1.3 mm emission arises from horizon scales, where intrinsic structural source variability is detected on timescales of minutes to hours. The effects of interstellar scattering on the image and its variability are found to be subdominant to intrinsic source structure. The calibrated visibility amplitudes, particularly the locations of the visibility minima, are broadly consistent with a blurred ring with a diameter of ∼50 μas, as determined in later works in this series. Contemporaneous multiwavelength monitoring of Sgr A* was performed at 22, 43, and 86 GHz and at near-infrared and X-ray wavelengths. Several X-ray flares from Sgr A* are detected by Chandra, one at low significance jointly with Swift on 2017 April 7 and the other at higher significance jointly with NuSTAR on 2017 April 11. The brighter April 11 flare is not observed simultaneously by the EHT but is followed by a significant increase in millimeter flux variability immediately after the X-ray outburst, indicating a likely connection in the emission physics near the event horizon. We compare Sgr A*'s broadband flux during the EHT campaign to its historical spectral energy distribution and find that both the quiescent emission and flare emission are consistent with its long-term behavior.http://iopscience.iop.org/2041-8205Physic