Method for rapid warning and activity concentration estimates in online waterγ-spectrometry systems

Onlineγ-spectrometry systems for inland waters,most of which extract samples in situ and in real time,are able to produce reliable activity concentration measurements for waterborne radionuclides only when they are distributed relatively uniformly and enter into a steady-state diffusion regime in the measurement chamber.To protect residents’health and ensure the safety of the living environment,better timeliness is required for this measurement method.To address this issue,this study established a mathematical model of the online waterγ-spectrometry system so that rapid warning and activity estimates can be obtained for water under non-steady-state(NSS)conditions.In addition,the detection efficiency of the detector for radionuclides during the NSS diffusion process was determined by applying the computational fluid dynamics technique in conjunction with Monte Carlo simulations.On this basis,a method was developed that allowed the online waterγ-spectrometry system to provide rapid warning and activity concentration estimates for radionuclides in water.Subsequent analysis of the NSS-mode measurements of^(40)K radioactive solutions with different activity concentrations determined the optimum warning threshold and measurement time for producing accurate activity concentration estimates for radionuclides.The experimental results show that the proposed NSS measurement method is able to give warning and yield accurate activity concentration estimates for radionuclides 55.42 and 69.42 min after the entry of a 10 Bq/L^(40)K radioactive solution into the measurement chamber,respectively.These times are much shorter than the 90 min required by the conventional measurement method.Furthermore,the NSS measurement method allows the measurement system to give rapid(within approximately 15 min)warning when the activity concentrations of some radionuclides reach their respective limits stipulated in the Guidelines for Drinking-water Quality of the WHO,suggesting that this method considerably enhances the warning capacity of in situ online waterγ-spectrometry systems.

Pure State Feedback Switching Control Based on the Online Estimated State for Stochastic Open Quantum Systems

For the n-qubit stochastic open quantum systems,based on the Lyapunov stability theorem and LaSalle’s invariant set principle,a pure state switching control based on on-line estimated state feedback(short for OQST-SFC)is proposed to realize the state transition the pure state of the target state including eigenstate and superposition state.The proposed switching control consists of a constant control and a control law designed based on the Lyapunov method,in which the Lyapunov function is the state distance of the system.The constant control is used to drive the system state from an initial state to the convergence domain only containing the target state,and a Lyapunov-based control is used to make the state enter the convergence domain and then continue to converge to the target state.At the same time,the continuous weak measurement of quantum system and the quantum state tomography method based on the on-line alternating direction multiplier(QST-OADM)are used to obtain the system information and estimate the quantum state which is used as the input of the quantum system controller.Then,the pure state feedback switching control method based on the on-line estimated state feedback is realized in an n-qubit stochastic open quantum system.The complete derivation process of n-qubit QST-OADM algorithm is given;Through strict theoretical proof and analysis,the convergence conditions to ensure any initial state of the quantum system to converge the target pure state are given.The proposed control method is applied to a 2-qubit stochastic open quantum system for numerical simulation experiments.Four possible different position cases between the initial estimated state and that of the controlled system are studied and discussed,and the performances of the state transition under the corresponding cases are analyzed.

数字普惠金融对乡村产业兴旺的影响研究——基于系统GMM和门槛效应分析

产业兴旺是乡村振兴的题中要义,利用金融力量激发产业兴旺活力是当前较为可行的方式。文章基于2011—2021年省级面板数据,使用系统GMM模型和动态面板门槛模型研究数字普惠金融与乡村产业兴旺之间的关系。结果表明:我国乡村产业兴旺水平在总体上呈现上升态势,且数字普惠金融能够对乡村产业兴旺起到良好的推进作用。分维度而言,数字普惠金融能够对乡村产业兴旺的各个维度产生不同的影响。分地区而言,数字普惠金融在中西部地区推动乡村产业兴旺建设的力度明显高于东部地区。通过进一步研究,数字普惠金融在促进乡村产业兴旺时,在其自身发展水平方面存在显著的双门槛效应。基于上述结果,文章从因地制宜执行三农相关政策、加大数字普惠金融实施力度、提高风险监测与控制水平等角度提出相应的对策建议。

Using a Spatial Convolution Method to Estimate Ecosystem Services Values at Regional Level: a Case Study in Northeast China

Since the introduction of the concept, studies on valuation of ecosystem services have been overwhelming, in cognizance of its great significance. In this article, the authors took Northeast China as the study area and applied the published coefficients for the world by Costanza to calculate the ecosystem services values through a spatial convolution method. The convolution analysis was done with a square processor with 5×5 neighborhood cells. The results showed that the ecosystem services value for the study area in the year 2003 was US$44 990 million which is US$89 million less than the value without operation, and the main contributions for that decrease were from water bodies, wetlands and estuaries. It is expected that this article can attract more interest to explore this field adopting geographic methods.

基于GMM聚类的AM-BiLSTM机场安检旅客流量预测

针对现有安检旅客流量预测研究大多为正常情况下的预测,未考虑异常突发情况下安检旅客流量的变化趋势,提出一种基于高斯混合模型(GMM)聚类的融合注意力机制的多变量双向长短期记忆(AM-BiLSTM)机场安检旅客流量预测模型。首先,利用GMM聚类算法对原始数据集使用日期特征和延误特征分别进行聚类分析,根据聚类所得的不同日安检旅客流量场景构建不同的AM-BiLSTM旅客流量预测模型。实验结果表明:与现有多种预测方法相比,该方法在不同场景下均能准确预测各时段的安检旅客流量。

A PRIORI L_2 ERROR ESTIMATES FOR A NONLINEAR PARABOLIC SYSTEM BASED ON COMBINING THE METHOD OF CHARACTERISTICS WITH MIXED FINITE ELEMENT PROCEDURE

A nonlinear parabolic system is derived to describe incompressible nuclear waste-disposal contamination in porous media. A sequential implicit tirne-stepping is defined, in which the pressure and Darcy velocity of the mixture are approximated simultaneously by a mixed finite element method and the brine, radionuclid and heat are treated by a combination of a Galerkin finite element method and the method of characteristics. Optimal-order convergence in L2 is proved. Time-truncation errors of standard procedures are reduced by time stepping along the characteristics of the hyperbolic part of the brine, radionuclide and heal equalios, temporal and spatial error are lossened by direct compulation of the velocity in the mixed method, as opposed to differentiation of the pressure.

A LARGE-SCALE ESTIMATE OF THE NUMBEROF PERIODIC SMALL OSCILLATIONS OFNONLINEAR SYSTEMS

A conservative system performing a small oscillation near every equilibrium position is analysed in classical way. The paper tries to answer the following question: How many types of the periodic small oscillation in the whole configuration space of the system are there? Making some hypotheses, it expresses the lower bounds of the number of the types for two cases where critical points of the potential function are nondegenerate and degenerate respectively by the Betti numbers and dimension of the constraint manifold only.

L^p-L^q decay estimates of solutions to Cauchy problems of thermoviscoelastic systems

L^p- L^q decay estimate of solution to Cauchy problem of a linear thermoviscoelastic system is studied. By using a diagonalization argument of frequency analysis, the coupled system will be decoupled micrologically. Then with the help of the information of characteristic roots for the coefficient matrix of the system, L^p- L^q decay estimate of parabolic type of solution to the Cauchy problem is obtained.

Models for Improving Software System Size Estimates during Development

This paper addresses the challenge of estimating eventual software system size during a development project. The ap-proach is to build a family of estimation models that use information about architectural design characteristics of the evolving software product as leading indicators of system size. Four models were developed to provide an increasingly accurate size estimate throughout the design process. Multivariate regression analyses were conducted using 21 Ada subsystems, totaling 183,000 lines of code. The models explain from 47% of the variation in delivered software size early in the design phase, to 89% late in the design phase.

基于改进GMM算法的非侵入式负荷监测方法研究

非侵入式负荷监测是实现电力负荷精细化管理的重要技术手段,负荷分解及特征提取是非侵入式负荷监测的关键环节。针对常规算法负荷特征提取弱或者过度拟合造成泛化能力低的问题,提出了基于拟合和聚类思想的负荷分解及特征提取算法,即改进的高斯混合模型(GMM)。首先通过引入AIC和BIC信息准则,分析不同混合成分个数下的GMM模型的拟合程度,选取最优的混合成分个数;其次研究和分析电力负荷功率信号的特征曲线,结合混合成分个数,改进初始值的选取;最后进行优化后的功率信号聚类分解,输出能充分体现时域功率曲线特征的特征矩阵。基于智能洗衣机洗涤模式下的实测功率信号,验证了改进GMM算法的可行性,并对模型改进前后的特征矩阵进行差异性分析,验证了采用改进高斯混合模型进行负荷分解得到的特征矩阵具有更好的信息表征能力及更好的训练识别特性。结果表明提出改进算法具有较强的自适应性以及较高的准确性。

E^2KF Based Joint Multiple CFOs and Channel Estimate for MIMO-OFDM Systems over High Mobility Scenarios

An enhanced extended Kalman filtering （E2KF） algorithm is proposed in this paper to cope with the joint multiple carrier frequency offsets （CFOs） and time-variant channel estimate for MIMO-OFDM systems over high mobility scenarios. It is unveiled that, the auto-regressive （AR） model not only provides an effective method to capture the dynamics of the channel parameters, which enables the prediction capability in the EKF algorithm, but also suggests an method to incorporate multiple successive pilot symbols for the improved measurement update.

基于Prophet-GMM的大坝监测数据异常检测算法

大坝监测数据受环境等因素影响,往往存在异常数据,异常数据的检测对于大坝的正常运行起着不可或缺的作用,但是传统异常检测算法对于大坝监测数据往往达不到精度要求。提出了一种基于Prophet-GMM的异常检测算法,利用Prophet算法较好的拟合性能对大坝数据进行拟合,由拟合数据与实测数据求残差序列,再利用GMM算法对残差序列进行聚类,从而准确识别出异常值。结果表明:Prophet-GMM法对于不同类型的大坝监测数据都能准确识别出异常值,与传统检测算法相比,在查准率、查全率及准确率3个检测指标上,均有较为明显的提升。

Testing the governance-performance relationship for the Tunisian banks: a GMM in system analysis

Rationale:This study aims to contribute to settling the lack of consensus regarding the determinants of bank performance,not only by considering bank governance,but also by including factors such as CEO compensation and risk management committee.Previous literature has included bank governance and considered only large banks in their surveys.The exclusion of other factors such as small-and medium-size banks may render the findings of these studies limited in applicability.Objective:The objective of this paper is to examine the impact of internal governance on bank performance.Methodology:To achieve this goal,we used annual data of a sample of ten Tunisian commercial banks listed in the Tunisian Stock Exchange observed during the period 1998–2015.We use the Generalized Method of Moments(GMM)to estimate the parameters of our econometric model.Results:Our study finds that the correlation between the size of the board of directors,the state’s inclusion,and the presence of independent directors is positive and significant.On the other hand,we have found that CEO compensation,as well as foreign and institutional investors negatively affect the performance of the banks.Conclusions and implications:Tunisian banks are invited to broaden their size through appropriate restructuring,adopt new remuneration policies and define the optimal number of directors representing the state within the board of directors.Our results suggest managerial implications that can be of great value to ensuring the success of Tunisian banks.The latter should favor a higher presence of independent directors to reduce the bank control ineffectiveness caused by having a significant number of foreign and institutional investors in the board of directors.

基于DBSCAN算法与GMM理论的铝合金板孔边疲劳裂纹萌生监测

针对航空结构中多孔铝合金板在疲劳载荷作用下的孔边裂纹萌生监测问题,以光纤传感系统为基础结合小波分解、含噪声的密度空间聚类以及高斯混合模型,提出了一种孔边裂纹萌生监测方法。首先以光纤光栅传感系统采集循环加载条件下多孔铝合金板孔边裂纹萌生至结构断裂全程中孔边微应变并构建孔边微应变曲线。对孔边微应变曲线进行小波分解,得到微应变曲线的低频分量与高频分量,并以低频分量最小值及高频分量突变作为孔边裂纹萌生特征。在分析裂纹萌生时引入DBSCAN算法与GMM理论用于计算孔边裂纹萌生时的疲劳加载循环数并进行比较与分析得到多孔铝合金板孔边主裂纹的萌生位置以及孔边主裂纹裂纹萌生时的疲劳加载循环数。试验结果表明:此监测方法能够准确定位出孔边主裂纹的萌生位置,计算孔边主裂纹萌生时的疲劳加载循环数,且疲劳加载循环数计算误差在5%以内。在未来可应用于全机地面疲劳试验、结构健康监测等多种场景。

The First Quantitative Slip-Rate Estimated Along the Ashikule Fault at the Western Segment of the Altyn Tagh Fault System

As one of the longest strike-slip fault in Asia,the Altyn Tagh Fault（ATF）defines the northern boundary of the Tibetan Plateau and plays a significant role inaccommodating the deformation resulting from the IndiaAsia convergence.

Nonlinear Phase Noise Estimate Based on Electronic Orthogonal Coherent for 112 Gb/s PDM-4QAM System

In this paper, we proposed a novel method of joint phase noise estimate (JPNE) for PDM-M-QAM (M = 4, 16, 32, 64, …) transmission systems, and established the theoretical model to illustrate the operation mechanism. The simulation of laser phase noise and fiber nonlinearity compensation based on the proposed JPNE method had also been demonstrated. For 112 Gb/s PDM-4QAM transmission system, the simulation results had showed that the optimum launch power increased from -4 dBm to at least 0 dBm compared with the condition of no phase noise compensation in reach of all simulation distances.

农村商业银行同业业务发展现状与风险承担水平研究——基于动态面板System GMM的实证分析

随着银行业同业业务的快速发展,地方性法人金融机构的同业业务逐渐成为其业务经营的重要方面,在规模扩张的同时也带来了各种经营风险。本文在梳理我国农村商业银行发展基础上,通过动态面板System GMM模型实证分析了同业业务对农村商业银行风险承担水平的影响。实证结果表明,农村商业银行同业资产与风险承担存在正向效应,即同业资产规模扩大将增加其风险承担;同业负债业务与风险承担呈负相关,即同业负债的增加会减少农商行的风险承担。

财政支农对农业现代化的动态影响研究--基于系统GMM及门槛效应的检验

农业现代化是我国保障粮食安全建设农业强国的头等大事,财政支农支出与农业现代化建设有着天然的契合性。为研究财政支农支出对农业现代化的作用与影响,文章首先从理论方面探讨了财政支农支出影响农业现代化发展的作用机理。随后,基于农业现代化内涵从农业机械化、产业化等五个维度构建了农业现代化测评指标体系,并采用熵值法测度2011-2021年中国内地31省域的农业现代化发展指数。在此基础上,选取系统GMM方法和门槛效应模型进一步验证财政支农支出作用农业现代化的动态影响及门槛特征。研究结果表明:我国农业现代化总体水平提升较慢,各省农业现代化发展趋势较好,但存在地区差异,发展不够均衡;财政支农支出对我国农业现代化发展水平具有显著正向促进作用;财政支农支出与农业现代化发展水平之间并不是简单的线性关系,财政支农支出对农业现代化的影响作用具有单一门槛特征。财政支农支出水平位于第一门槛值(10.872)水平时,财政支农支出对农业现代化的作用最为明显。最后,基于研究结果,分别从加强对各地区间的协调发展、进一步加大财政支农支出力度和优化财政支农支出结构等方面提出对策建议。研究结论为农业现代化的财政支农路径优化提供了科学决策依据。

Alternating current sensor system using GMM

Based on the principle of FBG sensing mechanism,an alternating current sensor system,which uses a FBG attached on a magnetostrictive rod as the probe,was developed.A dynamic interrogation method was proposed based on wide band light source,by making use of the linear relationship between its power intensity and wavelength as spectrum filter.A 50 Hz AC signal is interrogated successfully through the developed system and the system transfer function was established.The amplitude and frequency of the AC signal to be measured can be well deduced through the transfer function of the system, so the alternating current measurement is accomplished.

Model-driven full system dynamics estimation of PMSM-driven chain shell magazine

Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge exponentially to zero, and the parameter estimation error can be obtained from the extended state. Then, based on the extended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and excitation signal. Under persistent excitation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the extended state. Simulation and experimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.