LONG VALID TIME ENERGY PERFECT CONSERVATIVE FIDELITY SPECTRAL SCHEMES OF BAROTROPIC PRIMITIVE EQUATIONS

In accordance with a new compensation principle of discrete computations,the traditional meteo- rological global (pseudo-) spectral schemes of barotropic primitive equation (s) are transformed into perfect energy conservative fidelity schemes,thus resolving the problems of both nonlinear computa- tional instability and incomplete energy conservation,and raising the computational efficiency of the traditional schemes. As the numerical tests of the new schemes demonstrate,in solving the problem of energy conser- vation in operational computations,the new schemes can eliminate the (nonlinear) computational in- stability and,to some extent even the (nonlinear) computational diverging as found in the traditional schemes,Further contrasts between new and traditional schemes also indicate that,in discrete opera- tional computations,the new scheme in the case of nondivergence is capable of prolonging the valid in- tegral time of the corresponding traditional scheme,and eliminating certain kind of systematical com- putational“climate drift”,meanwhile increasing its computational accuracy and reducing its amount of computation.The working principle of this paper is also applicable to the problem concerning baroclin- ic primitive equations.

Efficient Dynamic Time Warping by Adaptively Controlling the Valid Warping Range

Dynamic time warping(DTW)spends most of the time in generating the correlation table,and it establishes the global path constraints to reduce the time complexity.However,the global constraints restrain just in terms of the time axis.In this paper,we therefore propose another version of DTW,to be called branch-and-bound DTW(BnB-DTW),which adaptively controb its global path constraints by reflecting the contents of input patterns. Experimental results show that the suggested BnB-DTW algorithm performs more efficiently than other conventional DTW approaches while not increasing the optimal warping cost.

Validation concurrency control protocol in parallel real-time database systems

In parallel real-time database systems, concurrency control protocols must satisfy time constraints as well as the integrity constraints. The authors present a validation concurrency control(VCC) protocol, which can enhance the performance of real-time concurrency control mechanism by reducing the number of transactions that might miss their deadlines, and compare the performance of validation concurrency control protocol with that of HP2PL(High priority two phase locking) protocol and OCC-TI-WAIT-50(Optimistic concurrency control-time interval-wait-50) protocol under shared-disk architecture by simulation. The simulation results reveal that the protocol the author presented can effectively reduce the number of transactions restarting which might miss their deadlines and performs better than HP2PL and OCC-TI-WAIT-50. It works well when arrival rate of transaction is lesser than threshold. However, due to resource contention the percentage of missing deadline increases sharply when arrival rate is greater than the threshold.

多模式对四川盆地强降水过程的预报性能检验

为进一步认识当前数值预报模式的预报能力,选取2018—2020年发生在四川盆地的47次强降水过程进行分型,再基于多源降水融合产品和地面观测资料,通过TS评分、时空滑动等方法对欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)数值预报模式、国家气象中心区域中尺度数值预报模式(China Meteorological Administration Mesoscale Model,CMA_MESO)和西南区域数值预报系统(Southwest Center WRF ADAS Real-time Modeling System,SWC_WARMS)在强降水过程范围、强度、极值、时间和位移偏差等方面的预报能力进行检验评估。结果表明,各模式08:00(北京时,下同)预报优于20:00预报,ECMWF对中雨和大雨预报更优,SWC_WARMS的暴雨量级评分更高。各模式对中雨的预报范围普遍较实况偏大,随着降水量级增大,逐渐转为低估,其中SWC_WARMS更接近实况。对于降水强度,ECMWF和CMA_MESO的平均降水量和极值普遍较实况偏小,SWC_WARMS更接近实况。3种模式时间偏差不明显,仅个别起报时次有-6~3 h的时间偏差;ECMWF的位移偏差最小,纬向上ECMWF和SWC_WARMS以偏北为主,经向上ECMWF以偏西为主,CMA_MESO和SWC_WARMS以偏东为主。

新时代加强大学生中共党史教育“时度效”的要求、问题与路径

“时度效”是检验中共党史教育成效的重要指标。新时代加强大学生中共党史教育“时度效”需要遵循坚持党性与时代性相统一、思想性与科学性相融合、精准性与有效性相结合等基本要求。从“时度效”视角透视新时代部分大学生中共党史教育问题,主要体现在“时”的掌握不准、“度”的把握不足、“效”的实现不佳三个方面,亟需以“育以因时”为基本点、以“育以适度”为关节点、以“育以有效”为落脚点,着力从更新教育理念内容、创新教育方式方法、提升党史育人质量三个层面协同推进、共同发力,以助力于新时代大学生中共党史教育提质增效。

Study on Multi-effect Time Parameters of Ergonomic Validity Index in Low-carbon Residential Kitchen

In the study on functional low-carbon ergonomic validity in buildings,ergonomic validity is different from resource validity which is easy for quantitative analysis. To eliminate the complexity and uncertainty impacts of human factors on quantitative study,it proposes a method of building a parameter of ergonomic validity—multi-effect time by using cardiotachometer to record heart rate change,being used to evaluate the functional low-carbon ergonomic validity targeting at the ontological characteristics of kitchen. This method is used to determine the physical consumption intensity( multi-effect) through heart rate incremental relation based on the principles of physiology and ergonomics,and to confirm the ergonomic validity of environmental factors by the time to complete standard work as well as multi-effect quantitative analysis. The test results show that,under the kitchen operating conditions,the multi-effect( ME) can properly reflect the real-time status of the operator and is easily operated; the parameters obtained are not significantly related to the physiological status of the operator,and multi-effect time( MT) is sensitive to the physical consumption brought about to the operator due to kitchen environmental factors; thus,it can be taken as an objective index,which is simple and easy to operate in residential kitchen functional low-carbon evaluation.

平衡时间观量表中文版测评高校学生的效度和信度

目的:检验平衡时间观量表(BTPS)中文版在高校学生群体中的效度和信度。方法:在样本1(n=500)中应用中文版BTPS施测,进行条目分析和探索性因子分析;在样本2(n=722)中以津巴多时间观量表(ZTPI)、学习投入量表(UWE-S)、幸福感指数量表(IWB)为效标工具检验其效标效度,并进行验证性因子分析;选取样本3(n=102)进行间隔3周的重测。结果:BTPS中文版共27条目,包含过去、未来2个维度。两因子模型拟合良好(χ^(2)/df=3.10,CFI=0.92,TLI=0.91,SRMR=0.05,RMSEA=0.05);效标检验显示,BTPS得分与ZTPI、UWE-S、IWB得分均正相关(ICC=0.59、0.70、0.68、0.51,均P<0.001)。总量表及过去、未来维度的Cronbachα系数分别为0.95、0.92、0.93;总量表及2个维度的重测信度(ICC)分别为0.85、0.80、0.84。结论:平衡时间观量表中文版测量高校学生时间观的效度和信度良好。

职业未来时间洞察力量表的汉化及信效度检验

目的:对英文版职业未来时间洞察力量表(Occupational Future Time Perspective Scale)进行汉化,并检验其信效度。方法:通过Brislin翻译-回译原则对职业未来时间洞察力量表进行直译、回译、文化调适和预测试后形成中文版职业未来时间洞察力量表。采用便利抽样法抽取河南省3所三级公立医院护士480人作为研究对象,进行信效度检验。结果:中文版职业未来时间洞察力量表包括3个维度、9个条目。量表条目水平的内容效度指数(I-CVI)为0.860~1.000,平均量表内容效度(S-CVI/Ave)为0.953。探索性因子分析提取3个公因子,累计方差贡献率为82.277%;验证性因子分析显示模型拟合度良好。量表Cronbach'sα系数为0.887,重测信度为0.876,折半信度为0.765。结论:中文版职业未来时间洞察力量表具有良好的信效度,可以作为评估我国护士职业未来时间洞察力的有效工具。

基于模型组合的电力负荷精准预测

电力负荷的预测涉及环境和社会因素,因此,设计一种高效准确的预测模型是电力行业的重要任务。设计了一种基于传统机器学习模型组合的电力负荷预测模型。该模型从特征层面入手并采用Wrapper与梯度的特征排序选择方法对主要特征进行筛选和优化。在实验中,对预测结果进行了基于时序扩展窗口拆分的K折时序交叉验证和比较。结果表明,该模型能够有效预测电力负荷的短期时序变化,且预测效果比传统的单一机器学习模型好。通过贝叶斯超参数调优方法得到的超参数组合能够显著提高模型的准确性和泛化能力。这说明贝叶斯超参数调优方法能够在一定程度上解决模型过拟合和欠拟合问题,提高模型的稳定性和可靠性。

基于分段特征提取的仿真模型结果验证方法

校核、验证与确认(verification,validation,and accreditation,VV&A)是保证仿真模型可信度的关键手段,其中模型验证是核心环节。针对导弹飞行仿真模型结果验证存在的参考数据不可获得、参考数据来源多样、专家验证主观性强等问题,提出一种基于时间序列分段特征提取的导弹飞行仿真模型结果验证方法。提出了一种综合的时间序列分段线性方法,由基于二阶导数提取趋势边缘点的线性分段算法和基于极值点优化的Top-Down线性分段算法两部分组成,以实现对导弹飞行仿真数据和参考数据进行有效的线性分段表示。基于上述分段结果,对各段时间序列的均值、方差、斜率等特征进行提取,以辅助专家进行验证,从而降低验证中的主观性;或者直接利用TIC系数法、动态时间规整(dynamic time warping,DTW)等方法进行客观的相似性分析。通过充分利用时间序列的分段特征,可实现各种情形下的导弹飞行仿真模型结果验证。通过一个导弹模型结果验证案例演示了所提方法的可行性和有效性。

基于改进BP的分子泵故障诊断研究

分子泵为EAST装置提供洁净的真空环境,其运行状态影响EAST实验的顺利开展。由于在EAST实验运行过程中,分子泵设备可能会出现异物坠入或者真空泄漏故障,对装置造成次生危害。针对分子泵故障数据集不平衡导致故障诊断精度低以及模型过拟合问题,提出一种基于时域频域预处理与改进BP相结合的算法,实现分子泵故障诊断。通过在BP神经网络的基础上,引入粒子群算法(PSO)并结合五折交叉验证优化模型。首先在模拟分子泵故障的破坏性测试平台上,采集正常态、真空泄漏以及异物坠入故障振动信号,然后对数据进行时域频域特征提取融合,将得到的特征向量集作为优化算法的输入,对模型进行训练,实现分子泵故障诊断。经实验验证,所提出改进BP算法在诊断精确率上可以达到96.84%,优于支持向量机(SVM)、K近邻(KNN)和BP算法。

基于DnCNN 的侵彻过载时频去噪方法

目的提高从侵彻过载中准确估计刚体过载信号的能力。方法提出一种基于前馈去噪卷积神经网络(DnCNN)的侵彻过载时频去噪方法,该方法首先应用短时傅里叶变换(STFT)提取侵彻过载信号的时频图像,使DnCNN能够充分利用时频图像信息,估计出刚体过载时频图像。最后,通过逆STFT将时频图像转换回时域,得到估计的刚体过载信号。结果在5-Fold交叉验证中,所提方法在测试集上的平均绝对误差(MAE)为0.968%,Pearson相关系数(r)为90.35%。与低通滤波、总体经验模态分解(EEMD)和小波变换方法相比,所提方法的平均MAE分别降低了1.82%、1.00%、0.75%,平均相关系数r值分别提高了47.81%、17.48%、22.93%。结论所提方法可以从侵彻过载中准确估计出刚体过载信号,在去噪能力上优于低通滤波、EEMD和小波变换方法,且在去噪过程中,无需调整参数,能够自动完成去噪任务。

食品中羊源性成分检测的方法学验证

本文主要依据SN/T 2051—2008标准对食品中羊源性成分检测进行特异性、灵敏度、稳定性等方法学验证,同时进行掺伪样和市售商品检测。结果表明,本方法灵敏度高(0.001%)、特异性强、稳定性好,适用于食品中羊源性成分检测。

通勤时耗、通勤方式及通勤活动对通勤享受的影响

通勤享受是衡量通勤积极效用的要素,是对现有通勤出行研究的重要补充。以通勤时耗、通勤方式及通勤活动3项重要指标作为研究对象设计通勤出行调查问卷,基于北京、上海、广州、深圳4个城市709份有效问卷数据研究对通勤享受的影响。使用SPSS 26.0软件和R语言4.1.3版对通勤享受量表进行信效度分析,并采用二次项回归和协方差分析进行不同群体通勤享受的差异检验。结果表明:通勤享受量表具有良好的信效度,通勤时耗与通勤享受存在非线性相关关系,通勤时耗约为29.5 min时通勤享受水平最高;不同通勤方式间通勤享受水平差异并不显著,步行和自行车出行并没有显示具有更高的通勤享受水平;相比于只进行通勤出行本身,在通勤过程中进行休闲娱乐活动能够显著提升通勤享受水平。最后,建议通过推进职住平衡、提高交通服务效率、改善通勤出行环境等措施改善通勤交通出行条件,以提高通勤享受水平、促进城市交通良性发展。

A metaheuristic method for the multireturn-to-depot petrol truck routing problem with time windows

The petrol truck routing problem is an important part of the petrol supply chain.This study focuses on determining routes for distributing petrol products from a depot to petrol stations with the objective of minimizing the total travel cost and the fixed cost required to use the trucks.We propose a mathematical model that considers petrol trucks returning to a depot multiple times and develop a heuristic algorithm based on a local branch-and-bound search with a tabu list and the Metropolis acceptance criterion.In addition,an approach that accelerates the solution process by adding several valid inequalities is presented.In this study,the trucks are homogeneous and have two compartments,and each truck can execute at most three tasks daily.The sales company arranges the transfer amount and the time windows for each station.The performance of the proposed algorithm is evaluated by comparing its results with the optimal results.In addition,a real-world case of routing petrol trucks in Beijing is studied to demonstrate the effectiveness of the proposed approach.

On the validity of the Boltzmann–BGK model through relaxation evaluation

The Boltzmann-Bhatnagar-Gross-Krook（BGK）model is investigated for its validity regarding the collision term approximation through relaxation evaluation. The evaluation is based on theoretical analysis and numerical comparison between the BGK and direct simulation Monte Carlo（DSMC） results for three specifically designed relaxation problems. In these problems, one or half component of the velocity distribution is characterized by another Maxwellian distribution with a different temperature. It is analyzed that the relaxation time in the BGK model is unequal to the molecular mean collision time. Relaxation of component distribution fails to involve enough contribution from other component distributions, which makes the BGK model unable to capture details of velocity distribution, especially when discontinuity exists in distribution. The BGK model,however, predicts satisfactory results including fluxes during relaxation when the temperature difference is small. Particularly, the model-induced error in the BGK model increases with the temperature difference, thus the model is more reliable for low-speed rarefied flows than for hypersonic flows.

基于血清代谢组学研究祛浊通痹方改善高脂饮食诱导的肥胖小鼠胆汁酸代谢紊乱

[目的]基于血清代谢组学探究祛浊通痹方(Quzhuo Tongbi,QZTB)改善高脂饮食(high fat diet,HFD)诱导的肥胖小鼠胆汁酸代谢紊乱的相关机制。[方法]将雄性C57BL/6J小鼠随机分为空白组、HFD模型组和QZTB组,采用超高效液相色谱-四极杆飞行时间串联质谱(ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry,UHPLC-QTOF-MS)技术进行血清代谢组学分析,筛选潜在生物标志物。通过实时荧光定量聚合酶链式反应(Real-time quantitative polymerase chain reaction,RT-qPCR)验证富集代谢通路的关键靶点。[结果]代谢组学分析共筛选到103个潜在生物标志物,主要富集到胆汁酸生物合成代谢通路,提示QZTB可明显改善HFD诱导的小鼠胆汁酸代谢紊乱。RT-qPCR结果显示,与空白组比较,HFD模型组小鼠肝组织胆固醇7α羟化酶(cholesterol 7-alpha hydroxylase,CYP7A1)、细胞色素P450家族8亚家族B成员1(cytochrome P450 family 8 subfamily B member 1,CYP8B1)、法尼醇X受体(farnesoid X receptor,FXR)及小异源二聚体(small heterodimer partner,SHP)表达量显著降低(P<0.01,P<0.01,P<0.001,P<0.01);经QZTB干预后经典途径关键酶CYP7A1与CYP8B1明显升高(P<0.01,P<0.05),FXR与SHP被激活(P<0.05),固醇调节元件结合蛋白-1C(sterol regulatory elementbinding protein-1C,SREBP-1C)和脂肪酸合成酶(fatty acid synthase,FAS)被显著抑制(P<0.01,P<0.001)。[结论]QZTB主要通过提高胆汁酸合成经典途径关键酶的活性,促进初级胆汁酸的合成,激活FXR-SHP通路,调节胆汁酸生物合成代谢途径,从而改善HFD诱导的肥胖小鼠胆汁酸代谢紊乱。

时变交通拥挤和需求随机的移动设施运营优化

为了优化移动设施(Mobile Facility,MF)的运营,在充分考虑时变交通状况和用户需求随机性的基础上,构建了一个两阶段随机规划模型,以期为决策者提供有力的工具。在第一阶段,模型针对MF的数量、时刻表和路径进行决策;第二阶段则聚焦于用户需求的分配和未满足服务量的确定。在求解此模型的过程中,本研究结合了时间依赖最短路径算法与L-shaped算法。在解决MF的移动路径和用户到达服务点的时间依赖最短路径问题时,将时变路段行驶速度离散化为分段函数,使得路段行驶时间成为连续分段线性函数,并且满足网络先进先出的原则,从而可以修改现有最短路径算法高效求解时间依赖最短路径。在L-shaped算法中,视一阶段模型为主问题,二阶段模型为子问题。首先通过求解主问题获得一阶段的决策变量,然后利用这些变量求解子问题,为主问题生成最优割。通过主、子问题的迭代交互,实现了对模型全局最优解的收敛,同时,通过加入有效不等式,使得算法能够快速收敛。在上海市嘉定区COVID-19核酸检测服务的MF实例中,对所提出的模型和算法进行了实证研究。结果表明:多割L-shaped算法结合有效不等式显著提升求解效率;同时,随着用户需求分布情况数量的增加,完美信息期望值和随机解价值均显著增加,这强调了在决策过程中获取准确信息和考虑时变交通状况与需求随机性的重要性。

基于岭回归的地铁车载设备故障预测

针对现场实际记录中屡次发生故障的车载设备,为预测其下一次故障发生时间,提出基于岭回归算法的故障时间预测方法,整个研究过程通过随机森林算法结合人为经验的方式提取出6个有效故障特征,建立岭回归故障预测模型,并通过网格搜索结合交叉验证(Gridsearch CV)的方法优化模型超参数,在深圳某地铁线路实际数据中得到有效的验证,提出的方法可以较为准确的预测下一次故障,可以作为指导预防性维修的依据,实现故障的提前预测、提前感知、提前处理。

Reliability and validity of the French version of the Global Physical Activity Questionnaire

Background:The Global Physical Activity Questionnaire(GPAQ)has been used to measure physical activity(PA)and sedentary time in France,but no study has assessed its psychometric properties.This study aimed to compare the reliability as well as criterion and concurrent validity of the French version of the GPAQ with the French International Physical Activity Questionnaire long form(IPAQ-LF)and use of an accelerometer in a general adult population.Methods:We included 92 participants(students or staff)from the Medicine Campus at the University of Lorraine,Nancy(north-eastern France).The French GPAQ was completed twice,7 days apart,to study test-retest reliability.The IPAQ-LF was used to assess concurrent validity of the GPAQ,and participants wore an accelerometer(ActiGraph GT3X+)for 7 days to study criterion validity.Reliability as well as concurrent and criterion validity of the GPAQ were tested by the intraclass correlation coefficient(ICC),Spearman correlation coefficient for quantitative variables,and Kappa and Phi coefficients for qualitative variables.Both concurrent and criterion validity of GPAQ were assessed by Bland-Altman plots.Results:The GPAQ showed poor to good reliability(ICC=0.37-0.94;Kappa=0.50-0.62)and concurrent validity(Spearman r=0.41-0.86),but only poor criterion validity(Spearman r=-0.22-0.42).Limits of agreement for the GPAQ and accelerometer were wide,with differences between 286.5 min/week and 601.3 min/week.Conclusion:The French version of the GPAQ provides limited but acceptable reliability and validity for the measurement of PA and sedentary time.It may be used for assessing PA and sedentary time in a French adult population.