An analysis of review content and reviewer variables that contribute to review helpfulness

Review helpfulness is attracting increasing attention of practitioners and academics. It helps in reducing risks and uncertainty faced by users in online shopping. This study examines uninvestigated variables by looking at not only the review characteristics but also important indicators of reviewers. Several significant review content and two reviewer variables are proposed and an effective review helpfulness prediction model is built using stochastic gradient boosting learning method. This study derived a mechanism to extract novel review content variables from review text. Six popular machine learning models and three real-life Amazon review data sets are used for analysis. Our results are robust to several product categories and along three Amazon review data sets. The results show that review content variables deliver the best performance as compared to the reviewer and state-of-the-art baseline as a standalone model. This study finds that reviewer helpfulness per day and syllables in review text strongly relates to review helpfulness. Moreover, the number of space, aux verb, drives words in review text and productivity score of a reviewer are also effective predictors of review helpfulness. The findings will help customers to write better reviews, help retailers to manage their websites intelligently and aid customers in their product purchasing decisions.     

在数学教学中融入探索研究--关于发现型讨论式教学的案例与思考

面对知识经济时代,数学教学中应该融入探索研究思想.本文从具体的案例出发,阐述了在教学活动中如何进行探索研究思想的渗透.     

光泵磁共振中的双射频子吸收

给出一种测量地磁的新方法，解释了实验中出现的双射频子吸收现象。     

生物大分子的共振光散射分析

文章介绍了共振光散射技术及其在生物大分子定量分析中的应用,并讨论了其发展方向和前景。     

个性·矛盾·悲鸣--论苏曼殊的感伤之旅

苏曼殊作为一个神秘、浪漫的文学天才,在近代中国东/西杂陈的剧烈动荡中,走过了他短暂而凄凉的一生.他孤独、矛盾的心灵在世纪末的风雨中痛苦挣扎、绝望哀鸣,这种浓郁的感伤情愫已融入他生命的深层,并成为他浪漫生命之旅中的一朵哀艳之花.他的感伤之旅主要包括个性主义反抗的矛盾性;与英国浪漫主义诗人拜伦的情感共鸣及个体反抗的精神畸变;浪漫感伤情怀在小说中的深入呈现等.     

Stabilization of stochastic nonholonomic systems

INTRODUCTION In recent years, much progress has been made in the design of control laws for systems subjected to nonholonomic constraint making it impossible to stabilize the system by any time-invariant continuous state feedback control law. This fact stimulates re- searchers to construct time-varying (Jiang and Ni- jmeijer, 1999; Jiang, 2001; Samson, 1995; Tian and Li, 2002) or discontinuous (Chang and Chen, 2002; Ge et al., 2003; Hu et al., 2004; Kim and Tsiotras, 2002; Mnif, 2004;…     

频散效应对铁磁共振曲线的影响

在铁磁共振实验中，通过铁磁共振曲线测量共振线宽十分重要，因为它表示铁磁材料磁损耗的大小。频散效应对铁磁共振曲线有明显的影响，该文从理论上分析了频散效应的物理本质以及它对铁磁共振曲线的影响，阐述了测量共振线宽的具体实验方法。     

浅谈“随机过程”课程教学改革与实践

“随机过程”是大多数研究生和少数高年级本科生的一门重要的专业基础课。如何提高“随机过程”教学效果?这是一个从事“随机过程”教学的教育工作者必须面对和深入探索的问题。本文从“随机过程”课程的现状、“随机过程”的教学目标、“随机过程”的教学内容、“随机过程”的教学方法和师生作用五个方面对该问题进行了分析,并且给出了相关改革建议。     

唱好高音的几个重要因素

基于专业教学经验的总结，对唱好高音的问题提出了自己的看法，认为唱好高音必须运用采取的方法是：真正打开喉龙；正确运用气息；声音“走向”正确无误；科学运用混合共鸣等。     

一种非线性方程的强非线性共振的转迁集

运用多尺度法和改进的L-P方法,通过引入参数变换把较大的摄动参数ε转换成小参数α,从而使讨论的非线性方程可用多尺度法和L-P方法求其近似解。求出了该方程亚谐共振(即k=1/2)时的分岔响应方程和转迁集。