Nonparametric fixed effects model for panel data with locally stationary regressors

We develop methods for inference in nonparametric time-varying fixed effects panel data models that allow for locally stationary regressors and for the time series length $T$ and cross-section size $N$ both being large. We first develop a pooled nonparametric profile least squares dummy variable approach to estimate the nonparametric function, and establish the optimal convergence rate and asymptotic normality of the resultant estimator. We then propose a test statistic to check whether the bivariate nonparametric function is time-varying or the time effect is separable, and derive the asymptotic distribution of the proposed test statistic. We present several simulated examples and two real data analyses to illustrate the finite sample performance of the proposed methods.     

NFC协议的模糊测试优化方案

针对NFC协议进行模糊测试方案时产生大量不符合协议规范的无效测试用例而导致测试效率较低的问题,应用图论思想,提出了基于生成的策略与深度优先算法融合后的模糊测试方案。在基于生成的策略下构造测试用例的过程中,遍历由协议规范连接成的测试需求图,以深度优先算法搜索图中覆盖点较多的生成路径,精简测试用例的生成路径,保证生成的测试用例能够接近协议规范。实验分析表明,所提出的模糊测试方案能够有效地减少无效测试用例的生成,提高测试效率。     

高层剪力墙结构问题的探析

高层剪力墙结构形式和布局要适度合理,需要按照“强剪弱弯”、“强柱弱梁”的总体建筑理念设计。可采用三维杆系的薄壁柱空间分析方法或墙组元的分析方法进行计算,但对墙肢长的剪力墙,应该用空间杆的墙组元程序进行校验。异形柱结构是多肢的,其延性较差,由于截面的特殊性,其各项承载能力也有较大差异。高层剪力墙结构通过恰当的布局、设计,达到高层建筑荷载力量均衡的目标。     

Data preprocessing and quantile regression for probabilistic load forecasting in the GEFCom2017 final match

Team QUINKAN competed in the GEFCom2017 final match of hierarchical probabilistic load forecasting by adopting the quantile regression method using the R package quantreg. The weather stations were clustered into 11 groups, from which an optimal one was chosen for each load meter using the boosting method. The load meter records were cleaned and/or supplemented by various methods in order to secure robust quantile predictions. The variation in the regression formulas was kept as small as possible by introducing measures for suppressing prediction instability, although special formulas were employed for loading meters that were of an industrial nature. Several procedures were applied to help improve the accuracy, such as the smoothing of season transitions, coarse graining of the relative humidity, the use of load-oriented day-type definition, the averaging of weather data, and outlier removal.     

食品检验检测中存在的问题分析及应对措施

食品安全是直接关系人们生活的重要问题,同时也是人们所关注的重点问题之一.实施食品安全管理可以有效减少安全事故发生,保障消费者权益.现阶段,食品市场中经常会存在一些安全问题,实施食品安全管理迫在眉睫,本文主要是针对食品检验检测中存在的问题开展分析,完善市场经济管理.     

Optimal surveillance against foot‐and‐mouth disease: the case of bulk milk testing in Australia

Previous foot‐and‐mouth disease (FMD) outbreaks and simulation‐based analyses suggest substantial payoffs from detecting an incursion early. However, no economic measures for early detection have been analysed in an optimising framework. We investigate the use of bulk milk testing (BMT) for active surveillance against an FMD incursion in Australia. We find that BMT can be justified, but only when the FMD entry probability is sufficiently high or the cost of BMT is low. However, BMT is well suited for post‐outbreak surveillance, to shorten the length of time and size of an epidemic and to facilitate an earlier return to market.     

The comprehensive business exam: Usefulness for assessing instructional and student performance outcomes

The authors explore the results of the Comprehensive Business Exam (CBE) administered to business majors during their senior-year business capstone course. The study results identified students' SAT and grade point average as a predictor of CBE performance, and variables that explain the correlation between CBE performance, SAT score, and grade point average are discussed. This study expands the research stream by demonstrating how faculty can use CBE information to more deeply assess student learning at both the course and instructor level than is possible with the Major Field Test for Bachelor's Degree in Business.     

生物工程技术在食品工业领域中的应用

生物工程技术作为21世纪的高新技术,在各个领域都能发挥出极关键作用.随着新技术的发展,生物工程技术在食品工业领域中更是绽放出了夺目的光彩.在本文中,笔者针对生物工程技术在食品资源开发、食品加工、食品资源安全检测、传统食品改良等方面的应用做出阐述,希望能为相关从业者提供新的工作思路.     

价值工程在特大型不锈钢封头制造中的应用

在对太空模拟训练仓中的特大形不锈钢封头制造中,运用了价值工程手段,并创新采用近似椭圆参数(R=0.8415D和r=0.1285D)和椭圆形封头顶圆的足球瓣结构,产品质量满足要求且降低了成本。     

罗布麻针织物性能测试与研究

随着人们生活水平的提高和对健康理念的逐步深入,对针织产品的舒适性和功能性要求也逐步提高,具有天然抗菌效果的罗布麻纱线被越来越多的应用到针织产品中。本文选取了100%纯罗布麻纱线和其它三种针织产品中常见的纱线——纯棉、纯羊毛和纯腈纶纱线,通过电脑横机以相同的编织参数编织成满针罗纹织物,然后对织物进行面密度、透气性和悬垂性等性能的测试,从而比较罗布麻针织物和其它纱线针织物的各项性能指标。`