A Multidimensional Item Response Theory Model for Continuous and Graded Responses With Error in Persons and Items     

Pere J. Ferrando  David Navarro-Gonzlez 《Educational and psychological measurement》2021,81(6):1029

Item response theory “dual” models (DMs) in which both items and individuals are viewed as sources of differential measurement error so far have been proposed only for unidimensional measures. This article proposes two multidimensional extensions of existing DMs: the M-DTCRM (dual Thurstonian continuous response model), intended for (approximately) continuous responses, and the M-DTGRM (dual Thurstonian graded response model), intended for ordered-categorical responses (including binary). A rationale for the extension to the multiple-content-dimensions case, which is based on the concept of the multidimensional location index, is first proposed and discussed. Then, the models are described using both the factor-analytic and the item response theory parameterizations. Procedures for (a) calibrating the items, (b) scoring individuals, (c) assessing model appropriateness, and (d) assessing measurement precision are finally discussed. The simulation results suggest that the proposal is quite feasible, and an illustrative example based on personality data is also provided. The proposals are submitted to be of particular interest for the case of multidimensional questionnaires in which the number of items per scale would not be enough for arriving at stable estimates if the existing unidimensional DMs were fitted on a separate-scale basis.  相似文献   

汇率变动的短期影响因素分析及其对跨国银行的影响     

崔鸿发  修国义 《科技与管理》2004,6(1):72-74

汇率变动受多种因素的影响，同时汇率的频繁波动也使跨国银行面临着巨大的汇率风险。从利率、中央银行的干预、市场投机等方面对影响汇率变动的短期因索进行分析，并阐述汇率变动对跨国银行的影响，以使跨国银行对汇率变动进行准确地预测、有效地管理汇率风险。  相似文献   

中国粮食价格波动的农户福利效应研究简   总被引：2，自引：1，他引：1  

苗珊珊 《资源科学》2014,36(2):370-378

本文基于1978-2011年中国粮食生产与消费的相关数据,在对粮食供需弹性以及粮食收益率估计的基础上,运用Minot福利效应模型,对粮食价格波动中农户福利的变动进行了测算与分解。结果表明：粮食价格波动的农户福利效应由两方面组成,包括农户作为净生产者的福利变动和其作为净消费者的福利变动。生产福利变动与粮食生产价格变动具有同向作用关系,粮食生产价格平均每提高10%,农户的短期生产福利将增加2.17%,长期生产福利增加2.19%;而消费福利变动与粮食销售价格变动具有负向作用关系,粮食销售价格平均每提高10%,短期消费福利减少1.44%,长期消费福利将减少1.34%。粮食价格变动引起农户收入与粮食消费支出变化的相对值决定农户总福利效应。最后本文分析了这一结论的政策性含义。  相似文献   

对量子噪声实虚部互关联情况下饱和激光模型光强涨落的分析     

李跃宏 《云南电大学报》2007,9(3):90-93

针对实、虚部关联的量子噪声及泵噪声驱动的饱和激光模型,基于近似福克—普郎克方程,推导激光强度定态概率分布函数,利用投影算子法,分析了由于量子噪声实虚部关联度λq导致锁相时的光强度关联函数C(τ)和集中驰豫时间Tc。通过计算机数据计算及作图,得到了定态情况下光强概率分布函数图形,讨论了量子噪声实、虚部的互关联对光强关联函数和集中驰豫时间的影响。结果表明:量子噪声实、虚部互关联会导致激光强度涨落增大。  相似文献   

自耗电极真空电弧炉控制系统的设计     

宁欣  李建朝 《河南科技学院学报》2007,35(2):64-66

针对纯模拟器件自耗电极真空电弧炉电极升降控制系统故障率高、维护量大等一系列问题,设计出了由PLC和模糊控制组成的电极升降控制系统。介绍了系统主要硬件配置,并给出了主程序循环块方框图。该系统控制算法采用模糊控制算法,且根据现场工艺要求实现了从手动到自动的无扰切换功能。实验运行数据表明,基于模糊控制规律的电弧炉电极升降PLC控制系统运行稳定可靠,操作方便,维护量小,对同行业的生产将起到推动作用。  相似文献   

On the stochastic dynamics of molecular conformation     

DENG Mao-lin ZHU Wei-qiu 《浙江大学学报(A卷英文版)》2007,8(9):1401-1407

An important functioning mechanism of biological macromolecules is the transition between different conformed states due to thermal fluctuation. In the present paper,a biological macromolecule is modeled as two strands with side chains facing each other,and its stochastic dynamics including the statistics of stationary motion and the statistics of conformational transition is studied by using the stochastic averaging method for quasi Hamiltonian systems. The theoretical results are confirmed with the results from Monte Carlo simulation.  相似文献   

两种激光模型的量子起伏     

张登玉 《湖南城市学院学报》1996,(5)

本文研究激光理论中使用的两种模型（Haken模型和Louised模型）的量子起伏。在原子变量绝热消除条件下，研究两种模型在阈值附近或远高于阈值时，输出光谱的振幅起伏，并给出两种模型相互逼近的条件。  相似文献   

Influence of temperature fluctuation on thermophilic anaerobic digestion of municipal organic solid waste     

Wu MC  Sun KW  Zhang Y 《Journal of Zhejiang University. Science. B》2006,7(3):180-185

INTRODUCTION The use of anaerobic process to treat municipal organic solid waste (MOSW) has dramatically in-creased recently. Anaerobic digestion can be carried out under ambient (<25 °C), mesophilic (25~45 °C) and thermophilic (>45 °C) conditions (El-Mashad et al., 2004). Thermophilic digestion has many advan-tages such as higher metabolic rate and higher con-sequent specific growth rate compared with meso-philic digestion, although the thermophilic bacteria death rate is higher (…  相似文献   

台湾产出周期波动的状态分解、冲击效应及走势判断     

陈鹏 《福建师范大学学报(哲学社会科学版)》2010,(1)

将一个国家或地区总产出应用现代计量技术进行分解,可以从整体上再现其中所隐含的经济波动的特征事实。本文运用状态分解方法,将1951-2008年台湾真实GDP序列数据分解成趋势成分与周期波动成分。研究结果表明:(1)台湾GDP随时间推移呈现周期波动特征,但其长期经济增长趋势仍然比较稳健;(2)台湾经济波动的冲击的因素主要来自供给与需求冲击的交互作用。  相似文献