上海市社区老年人牙列状态及其与衰弱和认知功能的关系

目的:探讨上海市社区老年人牙列状态及其与衰弱和认知障碍的关系。方法:选取2019年10月—2023年10月在上海市徐汇区某社区卫生服务中心参加老年人健康体检的240名老年居民为研究对象。根据对其进行的简易精神状况检查表评分结果将其分为认知功能异常组(n=119)、认知功能正常组(n=121),根据对其进行的Fried衰弱身体表型量表评分结果将其分为健康组(n=102)、衰弱前期组(n=103)、衰弱期组(n=35)。观察不同认知功能老年人、不同衰弱状态老年人牙齿数目及佩戴义齿情况,分析老年人牙列状态与衰弱及认知功能的关系。结果:不同性别和年龄老年人牙列完整、牙列缺损、牙列缺失者占比比较,差异均无统计学意义(P>0.05)。相较于认知功能正常组,认知功能异常组老年人佩戴义齿、牙齿数目>21颗占比显著减少。相较于健康组,衰弱前期组、衰弱期组老年人佩戴义齿、牙齿数目>21颗占比显著减少。与健康组对比,衰弱前期组、衰弱组老年人简易精神状况检查表评分均显著降低。logistic回归分析结果显示,牙齿数目的减少与衰弱及认知障碍呈负相关(β=-0.823, P<0.05)。结论:上海市社区老年人牙列状态对衰弱及认知功能均存在一定影响,牙列缺损可促进衰弱及认知障碍发展,且衰弱与认知障碍呈正相关关系。

基于密钥状态散列树的密钥存储管理方案

针对密文检索系统中多源数据加密带来的海量密钥存储管理问题,提出了以密钥状态散列树作为密钥派生结构的密钥存储管理方案。该方案借助根密钥及密钥派生树进行密钥计算,且只需要存储根密钥和树结构,大大降低了密钥存储开销;另外,该方案可以根据撤销状态值进行密钥撤销管理,解决了派生树密钥撤销及结构更新难题。安全分析表明,部分数据密钥的泄露并不会泄露其他数据机密性,且基于实际数据集的性能分析表明所提密钥管理方案在实际应用中是可行的。

柴油机燃油系临界失效状态的研究

以６１３５型柴油机为例，针对柴油机燃油系中主要偶件的失效进行了分析研究，根据各偶件磨损的不同程度对发动机功率的影响，经大量试验，得到了各偶件临界失效状态值，取得了可信的判断依据。

一种可配置的合并单元电压并列与切换方案研究

合并单元电压并列与切换功能是单母分段或双母线接线变电站中保证供电可靠性的重要手段。针对利用编程语言实现的合并单元电压并列与切换功能的灵活性差且难保证程序稳定的特点,提出了一种通过配置状态列控制二次电压并列与切换功能的方案。通过分析合并单元电压并列与切换的特点,配置逻辑状态列和接收刀闸开入量,使用逻辑判别机制判断合并单元使用的结果状态列,并通过SV9-2输出。实验证明通过配置合并单元并列与切换状态列,能够实现二次电压并列与切换功能,满足功能指标,提高了合并单元的稳定性和灵活性。

Optimal state and branch sequence based parameter estimation of continuous hidden Markov model

A parameter estimation algorithm of the continuous hidden Markov model isintroduced and the rigorous proof of its convergence is also included. The algorithm uses theViterbi algorithm instead of K-means clustering used in the segmental K-means algorithm to determineoptimal state and branch sequences. Based on the optimal sequence, parameters are estimated withmaximum-likelihood as objective functions. Comparisons with the traditional Baum-Welch and segmentalK-means algorithms on various aspects, such as optimal objectives and fundamentals, are made. Allthree algorithms are applied to face recognition. Results indicate that the proposed algorithm canreduce training time with comparable recognition rate and it is least sensitive to the training set.So its average performance exceeds the other two.

Effects of Snow Cover on Ground Thermal Regime： A Case Study in Heilongjiang Province of China

The important effects of snow cover to ground thermal decades. In the most of previous research, the effects were usually regime has received much attention of scholars during the past few evaluated through the numerical models and many important results are found. However, less examples and insufficient data based on field measurements are available to show natural cases. In the present work, a typical case study in Mohe and Beijicun meteorological stations, which both are located in the most northern tip of China, is given to show the effects of snow cover on the ground thermal regime. The spatial （the ground profile） and time series analysis in the extremely snowy winter of 2012-2013 in Heilongjiang Province are also performed by contrast with those in the winter of 2011-2012 based on the measured data collected by 63 meteorological stations, Our results illustrate the positive （warmer） effect of snow cover on the ground temperature （GT） on the daily basis, the highest difference between GT and daily mean air temperature （DGAT） is as high as 32.35℃. Moreover, by the lag time analysis method it is found that the response time of GT from 0 cm to 20 cm ground depth to the alternate change of snow depth has 10 days lag, while at 40 cm depth the response of DGAT is not significant. This result is different from the previous research by modeling, in which the resnonse denth of ground to the alteration of snow depth is far more than 40 cm.

Instability and Death of Spiral Wave in a Two-Dimensional Array of Hindmarsh-Rose Neurons

Spiral wave could be observed in the excitable media, the neurons are often excitable within appropriateparameters. The appearance and formation of spiral wave in the cardiac tissue is linked to monomorphic ventriculartachycardia that can denervate into polymorphic tachycardia and ventricular fibrillation. The neuronal system oftenconsists of a large number of neurons with complex connections. In this paper, we theoretically study the transitionfrom spiral wave to spiral turbulence and homogeneous state (death of spiral wave) in two-dimensional array of theHindmarsh-Rose neuron with completely nearest-neighbor connections. In our numerical studies, a stable rotating spiralwave is developed and selected as the initial state, then the bifurcation parameters are changed to different values toobserve the transition from spiral wave to homogeneous state, breakup of spiral wave and weak change of spiral wave,respectively. A statistical factor of synchronization is defined with the mean field theory to analyze the transition fromspiral wave to other spatial states, and the snapshots of the membrane potentials of all neurons and time series of meanmembrane potentials of all neurons are also plotted to discuss the change of spiral wave. It is found that the sharpchanging points in the curve for factor of synchronization vs. bifurcation parameter indicate sudden transition fromspiral wave to other states. And the results are independent of the number of neurons we used.

基于改进人工蜂群算法的机器人任务最优指派

为了快速准确地求解机器人任务最优指派问题,本文提出了一种改进的人工蜂群算法。考虑到指派问题解决方案离散性的特点,在应用蜂群算法求解问题的过程中对可行解空间进行离散编码;在采蜜蜂和观察蜂更新解时,采用列状态转移的方法生成候选解,保证解的可行性和多样性。实验结果表明,改进的蜂群算法在求解指派问题模型时,具有良好的收敛速度和求解精度。

Interactions of Two Identical Wave Trains with a Relative Separation Angle of 24?

Interactions between two identical monochromatic wave trains with a relative separation angle of 24? were experimentally investigated in a well-designed ‘X' configuration.Wave trains with different amplitudes and frequencies were generated.The results demonstrated that the interaction was strongly dependent on both wave amplitude and frequency.For nonbreaking and lower-frequency cases,the wave trains can approximately reestablish their initial state following the interaction.However,for larger waves,the interaction was enhanced,distorting the surfaces significantly-the wave trains were no longer two-dimensional after the encounter.During the interaction process,there was an obvious increase in wave height,reaching a maximum amplification in the middle of the interaction region that was approximately 1.55 times the initial height.Furthermore,the images captured by high-speed cameras illustrated that two wave trains entered the interaction region at the same time and then merged during the interaction process,resulting in an increase in wave amplitude.The combined wave crest was initially composed of two straight segments with a relative angle of 24? and gradually morphed into a single segment as is evident in the plan view.The wave then broke in the downstream,still within the interaction region,exhibiting a crescent pattern along the crest.

LINEAR FILTERING FOR VASICEK TERM STRUCTURE MODEL WITH SEQUENTIALLY CORRELATED NOISE

When Kalman filter is used in the estimation of Vasicek term structure of interest rates,it is usual to assume that the measurement noise is uncorrelated.Study results are more favorable to the assumption of correlated measurement noise.An augmented state Kalman filter form for Vasicek model is proposed to optimally estimate the unobservable state variable with the assumption of correlated measurement noise.Empirical results indicate that the model with sequentially correlated measurement noise can more accurately describe the dynamics of the term structure of interest rates.

DAMAGE LOCATION DUE TO CORROSION IN REINFORCED CONCRETE STRUCTURES

An investigation on damage location due to the corrosion in reinforced concrete structures is conducted. The frequency change square ratio is used as a parameter for the damage. It is theoretically verified that the parameter is a function of the damage location. Experimental results of the corrosion in reinforced concrete structures show that the predicted damage location is in agreement with the real damage location. The modal parameters are used to detect the damages in structural concrete elements, and so they are useful for structural appraisal.

Entropy of Partitions on Quantum Logic

Partition and entropy of partitions in quantum logic are introduced and their properties are investigated.The results are generalized to the general case of T-norm and T-conorm.

Remaining Useful Life Prediction of Aeroengine Based on Principal Component Analysis and One-Dimensional Convolutional Neural Network

In order to directly construct the mapping between multiple state parameters and remaining useful life(RUL),and reduce the interference of random error on prediction accuracy,a RUL prediction model of aeroengine based on principal component analysis(PCA)and one-dimensional convolution neural network(1D-CNN)is proposed in this paper.Firstly,multiple state parameters corresponding to massive cycles of aeroengine are collected and brought into PCA for dimensionality reduction,and principal components are extracted for further time series prediction.Secondly,the 1D-CNN model is constructed to directly study the mapping between principal components and RUL.Multiple convolution and pooling operations are applied for deep feature extraction,and the end-to-end RUL prediction of aeroengine can be realized.Experimental results show that the most effective principal component from the multiple state parameters can be obtained by PCA,and the long time series of multiple state parameters can be directly mapped to RUL by 1D-CNN,so as to improve the efficiency and accuracy of RUL prediction.Compared with other traditional models,the proposed method also has lower prediction error and better robustness.

Real-time road traffic states estimation based on kernel-KNN matching of road traffic spatial characteristics

The accurate estimation of road traffic states can provide decision making for travelers and traffic managers. In this work,an algorithm based on kernel-k nearest neighbor(KNN) matching of road traffic spatial characteristics is presented to estimate road traffic states. Firstly, the representative road traffic state data were extracted to establish the reference sequences of road traffic running characteristics(RSRTRC). Secondly, the spatial road traffic state data sequence was selected and the kernel function was constructed, with which the spatial road traffic data sequence could be mapped into a high dimensional feature space. Thirdly, the referenced and current spatial road traffic data sequences were extracted and the Euclidean distances in the feature space between them were obtained. Finally, the road traffic states were estimated from weighted averages of the selected k road traffic states, which corresponded to the nearest Euclidean distances. Several typical links in Beijing were adopted for case studies. The final results of the experiments show that the accuracy of this algorithm for estimating speed and volume is 95.27% and 91.32% respectively, which prove that this road traffic states estimation approach based on kernel-KNN matching of road traffic spatial characteristics is feasible and can achieve a high accuracy.

Research on the Summer Drought in Chongqing Using MODIS-EVI Time Series Data

MODIS-EVI time series data from 2000 to 2009 in Chongqing were selected for this study.By the use of best index slope extraction （BISE） method for cloud elimination,analysis on the change vector of EVI time series data were conducted to investigate the EVI response on drought; then,four typical regions were selected to study the relationship between precipitation,temperature and EVI when the sever drought occurred in 2006; finally,based on the time series of vegetation condition index （VCI） and precipitation abnormity percentage,the temporal and spatial distributions of drought were studied.The results showed that,the EVI value of the summer in 2006 was significantly lower than the average EVI at the corresponding period of the other years in Chongqing.In addition,summer drought occurred mainly during the hot and dry weather.Except the southeast area,most of the other regions in Chongqing were all under severe drought.

Energy-Efficient Resource Allocation for Small-Cell Networks：A Stable Queue Perspective

The small-cell technology is promising for spectral-efficiency enhancement. However, it usually requires a huge amount of energy consumption. In this paper, queue state information and channel state information are jointly utilized to minimize the time average of overall energy consumption for a multi-carrier small-cell network, where the inter-cell interference is an intractable problem. Based on the Lyapunov optimization theory, the problem could be solved by dynamically optimizing the problem of user assignment, carrier allocation and power allocation in each time slot. As the optimization problem is NP-hard, we propose a heuristic iteration algorithm to solve it. Numerical results verify that the heuristic algorithm offers an approximate performance as the brute-force algorithm. Moreover, it could bring down the overall energy consumption to different degrees according to the variation of traffic load. Meanwhile, it could achieve the same sum rate as the algorithm which focuses on maximizing system sum rate.

An Image Encryption Approach Using a Shuffling Map

A new image encryption approach is proposed.First,a sort transformation based on nonlinear chaoticalgorithm is used to shuffle the positions of image pixels.Then the states of hyper-chaos are used to change the greyvalues of the shuffled image according to the changed chaotic values of the same position between the above nonlinearchaotic sequence and the sorted chaotic sequence.The experimental results demonstrate that the image encryptionscheme based on a shuffling map shows advantages of large key space and high-level security.Compared with someencryption algorithms,the suggested encryption scheme is more secure.

Single Server Queueing Models and Birth-Death Process

A transition diagram is used to describe the behavior of systems. Birth-death equations were derived from transition diagram depicting the state of the birth-death processes. Queue models and characteristics of queue models are also derivable from birth-death processes. These queue models consist of mathematical formulas and relationships that can be used to determine the operating characteristics （performance measures） for a waiting line. Schematic and transition diagrams of different single server queue models were shown. Relationships between birth-death processes, waiting lines （queues） and transition diagrams were given. While M/M/I/K queue model states was limited by K customers and had （K＋I） states, M/M/1/1 queue model had only two states. M/G/1/∝/∝ and M/M/1/∝/∝ shared similar characteristics. Many ideal queuing situations employ M/M/1 queueing model.

Comparative Study of Changes in Stress-drop of the Jinggu MS6.6 and Ludian MS6.5 Earthquake Sequences

The earthquake stress-drop values of two sequences were accurately calculated after taking away the effects due to regional earthquake anelastic attenuation and station site response,using waveform data and seismic phase data of sequences of the Jinggu M_S6. 6,and Ludian M_S6. 5 earthquakes in Yunnan. These results show that the stress drop with magnitude increases within the scope of this study of magnitude. After eliminating the influence of the magnitude,the average value of stress-drop in the Jinggu sequence is higher than that of the Ludian sequence at the same magnitude range. This may be related to the stress state in different regions. In terms of the changes of time and space of stress-drop,before M_S5. 8 strong aftershock,the stress-drop is "slowing down-turning up-keeping a high value"after the mainshock,meanwhile,almost all of the abnormally high stress drop value is distributed around the M_S5. 8 strong aftershock, showing that the stress environment in the region was increasing after the mainshock. And after the M_S5. 9 strong aftershock,stress-drop rapidly declines to a relatively stable state,meanwhile,the high value of stress-drop is distributed around the strong aftershock,showing that the regional tectonic stress gets more fully release,its stress environment begins to rapidly decrease.For the Ludian sequence without a strong aftershock occurring,the average value of stress drop is lower than that of the Jinggu earthquake sequence at the same magnitude range,while at the same time,the stress-drop of the aftershock sequence almost hasn't changed much. In the time after the mainshock,combined with the release characteristics of the main energy,the stress in the region is excessively released,the subsequent stress in the region gradually returns to normal. This may be the reason why the activity of Ludianaftershocks significantly was weaker and subsequently there were no strong aftershocks occurred.

数字化正颌外科中锥形束CT重建牙列与激光扫描牙模配准精度影响因素研究

目的评价锥形束CT(CBCT)重建牙列与激光扫描牙模配准时,托槽、牙列状态及配准方法3个因素对配准精度的影响。方法回顾性分析天津市口腔医院正颌外科2017年12月至2019年12月接受数字化设计的双颌手术治疗的患者资料。将患者的CBCT及激光扫描牙模(简称光扫牙模)数据导入Mimics 20.0软件,分别采用全局配准、局部配准对非咬合状态及咬合状态CBCT牙列和光扫牙模进行配准操作,分为4组:组1,非咬合状态牙列局部配准;组2,非咬合状态牙列全局配准;组3,咬合状态牙列局部配准;组4,咬合状态牙列全局配准。每组包括3个亚组:A亚组使用3.0 mm距离参数配准1次,B亚组使用3.0、1.5 mm距离参数配准2次,C亚组使用3.0、1.5、0.3 mm距离参数配准3次。借助Geomagic Studio软件的距离分析功能,获得两图像间距离的均方根(RMS)等配准精度数据。亚组间正态分布计量资料比较采用方差分析,各亚组间多重比较采用LSD-t检验;采用多因素方差分析,建立一般线性模型,检验有无托槽、牙列状态及配准方法三者之间是否存在交互作用,再使用单变量检验分析单独效应。结果共纳入24例患者,男7例,女17例,年龄19~30岁,其中12例有正畸金属托槽,12例无托槽。(1)无论有无托槽、咬合/非咬合状态牙列,采用局部配准时均为A亚组的配准方案最优,而采用全局配准时均为C亚组的配准方案最佳。(2)有无托槽、牙列状态、配准方法3个主变量对配准结果的影响均有统计学意义(P<0.05);三者间的交互作用无统计学意义(P>0.05);但有无托槽与牙列状态、有无托槽与配准方法、牙列状态与配准方法两两间交互作用有统计学意义(P<0.05)。结论在CBCT牙列和光扫牙模进行配准时,若使用局部配准法,只需用3.0 mm的距离参数配准1次;若使用全局配准法,需依次按照3.0、1.5、0.3 mm的距离参数设置配准3次。有无托槽、牙列状态、配准方法对CBCT牙列和光扫牙模的配准精度均有影响。