Parent academic involvement as related to school behavior, achievement, and aspirations: demographic variations across adolescence

A longitudinal model of parent academic involvement, behavioral problems, achievement, and aspirations was examined for 463 adolescents, followed from 7th (approximately 12 years old) through 11th (approximately 16 years old) grades. Parent academic involvement in 7th grade was negatively related to 8th-grade behavioral problems and positively related to 11th-grade aspirations. There were variations across parental education levels and ethnicity: Among the higher parental education group, parent academic involvement was related to fewer behavioral problems, which were related to achievement and then aspirations. For the lower parental education group, parent academic involvement was related to aspirations but not to behavior or achievement. Parent academic involvement was positively related to achievement for African Americans but not for European Americans. Parent academic involvement may be interpreted differently and serve different purposes across sociodemographic backgrounds.     

反者道之动(2本)——后现代主义思潮与教育

从后现代主义的起源、流变及其表现形式来看,后现代主义思潮具有反传统、反理性、多元化、自组织等特征.这种思潮已经波及科学及教育领域,正在并将继续对教育科学的理论及实战产生诸多正面、负面的影响.     

Parsimonious translation models for information retrieval

In the KL divergence framework, the extended language modeling approach has a critical problem of estimating a query model, which is the probabilistic model that encodes the user’s information need. For query expansion in initial retrieval, the translation model had been proposed to involve term co-occurrence statistics. However, the translation model was difficult to apply, because the term co-occurrence statistics must be constructed in the offline time. Especially in a large collection, constructing such a large matrix of term co-occurrences statistics prohibitively increases time and space complexity. In addition, reliable retrieval performance cannot be guaranteed because the translation model may comprise noisy non-topical terms in documents. To resolve these problems, this paper investigates an effective method to construct co-occurrence statistics and eliminate noisy terms by employing a parsimonious translation model. The parsimonious translation model is a compact version of a translation model that can reduce the number of terms containing non-zero probabilities by eliminating non-topical terms in documents. Through experimentation on seven different test collections, we show that the query model estimated from the parsimonious translation model significantly outperforms not only the baseline language modeling, but also the non-parsimonious models.     

Concurrent droplet charging and sorting by electrostatic actuation

This paper presents a droplet-based microfluidic device for concurrent droplet charging and sorting by electrostatic actuation. Water-in-oil droplets can be charged on generation by synchronized electrostatic actuation. Then, simultaneously, the precharged droplets can be electrostatically steered into any designated laminar streamline, thus they can be sorted into one of multiple sorting channels one by one in a controlled fashion. In this paper, we studied the size dependence of the water droplets under various relative flow rates of water and oil. We demonstrated the concurrent charging and sorting of up to 600 droplets∕s by synchronized electrostatic actuation. Finally, we investigated optimized voltages for stable droplet charging and sorting. This is an essential enabling technology for fast, robust, and multiplexed sorting of microdroplets, and for the droplet-based microfluidic systems.