基于MFFAKF的微惯导磁匹配粗对准方法

针对微机电系统(MEMS)陀螺仪精度低,无法完成惯导系统方位对准的问题,该文提出一种采用加速度计与磁强计输出完成MEMS惯导系统粗对准法。同时针对遗忘卡尔曼滤波法的缺点,提出将一种多遗忘因子自适应卡尔曼滤波法(MFFAKF)引入系统的对准方案中。该方法通过基于指数渐消记忆的方式计算量测噪声方差阵,并采用多遗忘因子调节不同的滤波通道。实验结果表明,采用MFFAKF得到的粗对准航向角精度满足MEMS惯导系统粗对准要求。     

Simultaneous Prediction for Multiple Key Performance Indicators in Semiconductor Wafer Fabrication

The prediction and key factors identification for lot Cycle time (CT) and Equipment utilization (EU) which remain the Key performance indicators (KPI)are vital for multi-objective optimization in semiconductor manufacturing industry.This paper proposes a prediction methodology which predicts CT and EU simultaneously and identifies their key factors.Bayesian neural network (BNN) is used to establish the simultaneous prediction model for Multiple key performance indicators (MKPI),and Bayes theorem is key solution in model complexity controlling.The closed-loop structure is built to keep the stability of MKPI prediction model and the weight analysis method is the basis of identifying the key factors for CT and EU.Compared with Artificial neural network (ANN)and Selective naive Bayesian classifier (SNBC),the simulation results of the prediction method of BNN are proved to be more feasible and effective.The prediction accuracy of BNN has been obviously improved than ANN and SNBC.     

LED电视在2D模式下的视觉健康舒适度测试研究

通过客观量测人眼观视时的各项视觉生理指标,并将各项指标嵌入人眼健康舒适度评价模型进行分析运算。经由583人次的人因实验,从视觉健康舒适度、电视屏幕人眼色觉客观量化反馈以及操控可用性3个方面对12款主流品牌的LED电视样机的视觉健康舒适度与人机交互设计进行了测试与评价。     

基于RCM 的导弹装备最佳预防性维修周期决策

针对目前确定预防性维修周期时存在不确定性的问题,建立了基于RCM的导弹装备维修周期决策模型。分别以总费用最小和可用度最大为目标建立导弹装备维修周期决策模型,采用蒙特卡罗仿真进行模型求解,采用模糊决策方法确定多目标综合最佳预防性维修周期,并以某型导弹装备密封圈为例,验证方法的有效性。实践分析结果表明:该方法综合权衡了费用和可用度因素,能较好地解决可用度低下且维修费用居高不下的问题,有一定应用和参考价值。     

水力压裂裂缝几何形态的数值模拟及影响因素分析

本文利用具有最优系数的线性四步法求解了水力压裂裂缝几何形态的数学模型,从而求得了裂缝各截面的高度、宽度和压力。通过大量的计算,对影响裂缝几何形态的因素进行了分析。与此同时,本文给出了比较合理的流量模型和粘度模型。     

对科学的态度：概念、影响因素及测量

我国对科学的态度有关研究始于20世纪90年代初期,起步较晚,此领域的学者以及研究机构较少,已有研究较为零散。在《全民科学素质行动计划纲要（2006-2010-2020年）》的指导下,我国已将民众对科学的态度列入科学素质的测评体系中,并且作为核心要素用于指导全民科学素质的提高。本文拟从态度理论研究入手,对科学的态度研究（概念、影响因素及测量）进行回顾与总结,提出我国对科学的态度研究中的不足以及未来努力的方向。     

Psychosocial predictors of cigarette smoking among adolescents living in public housing developments

BACKGROUND: Adolescents residing in low-income public housing developments in inner-city regions may be particularly vulnerable to a variety of risk factors associated with cigarette smoking. OBJECTIVE: To elucidate the aetiology of cigarette smoking among adolescents living in public housing developments. DESIGN, SETTING, AND SUBJECTS: We examined predictors of smoking from four domains: background characteristics, social influences, behavioural control, and psychosocial characteristics using a sample of seventh graders (mean age 12.9 years) who reside in public housing developments in New York City (n = 624). The addresses of participants in a larger investigation of the aetiology and prevention of smoking were checked to determine if they lived in one of 335 public housing developments in New York City. All participants living in public housing developments were included in the current study. MAIN OUTCOME MEASURES: African-American and Hispanic students completed questionnaires about their cigarette use, social pressures to smoke, smoking attitudes, smoking knowledge, and smoking resistance skills. Students also provided information on demographic and behavioural control (such as church and school attendance). RESULTS: Logistic regression analyses indicated that social influences from friends and family members predicted smoking. Psychosocial characteristics such as advertising resistance skills, anti-smoking attitudes, and refusal skills lowered the odds of smoking. CONCLUSIONS: These findings suggest that smoking prevention approaches targeted at these young people should increase their awareness of social pressures to smoke, correct misperceptions about the prevalence of smoking among friends, and teach relevant psychosocial skills.     

In vitro and in vivo determinations of sun protection factors of sunscreen lotions with octylmethoxycinnamate

The aim of this work was to evaluate the correlation between in vitro and in vivo determinations of sun protection factors (SPF) of sunscreen lotions containing the synthetic sunscreen octyl methoxycinnamate. Three sunscreen lotions containing either 2, 4.5 or 7.5% octyl methoxycinnamate were prepared. The in vitro SPFs of these sunscreen lotions were determined according to the spectrophotometric method of Mansur et al. The in vivo SPF values were determined according to the Food and Drug Administration (FDA) method. The results indicate that there was a good correlation between the in vitro and in vivo determinations for the sunscreen lotions examined.     

Reflectivity Model of Low Grazing Angle Radar Sea Clutter

The commonly used reflectivity models of radar sea clutter are summarized. Among these models, the adjusted Barton model and the adjusted Morchin model are compared. From the analysis result, the γ-p reflectivity model is presented for low grazing angle radar sea clutter by the adjustment of the original Barton reflectivity model. The model takes into account radar frequency, grazing angle, sea condition, and polarization property. The influences of these factors on the proposed model are analyzed. The model absorbs the merits from commonly used reflectivity models for sea clutter. It introduces several researchers‘ opinions, and extends them. And it accounts for the reflectivity at arbitrary radar frequency from VHF to X-band, arbitrary low grazing angle, arbitrary sea condition and different polarization property. One of the main results is the proposed γ-p reflectivity model can reflect the influence of polarization on sea clutter reflectivity to some extent. The proposed γ-p reflectivity model of low-angle radar-sea clutter is validated by comparing the simulated and statistically experimental data.     

Parameter design using the Taguchi methodology

This article aims to give an overview of the Taguchi methodology and more specific of its key step: parameter design. The purpose of parameter design is to bring quality into the product/process by determining the relevant parameters and their optimal settings such that the quality characteristics of the product are optimised and have minimal sensitivity to “noise” (i.e., those disturbing factors which are difficult or too expensive to control). The (mainly statistical) tools used in the methodology will be handled and some actual Bell cases will be mentioned as practical examples.