We estimate the effects of attending the first versus second-tier of higher education institutions on Chinese students' at-college and expected post-college outcomes using various quasi-experimental methods such as regression discontinuity, genetic matching, and regression discontinuity controlling for covariates. Overall we find that just attending the first versus second-tier makes little dif...

Spatially organized clusters are basic structure for large-scale wireless sensor networks. A cluster is generally composed by a large amount of energy-limited low-tier nodes (LNs), which are managed by a powerful cluster head (CH). The low-tier nodes that are close to the cluster head generally become bottlenecks in data collection applications. Energy efficient scheduling is important for the ...

Motivated by allocation of cloud computing services, bandwidth and wireless spectrum in secondary network markets, we introduce a hierarchical auction model for network resource allocation. The Tier 1 provider owns all of the resource, who holds an auction in which the Tier 2 providers participate. Each of the Tier 2 providers then holds an auction to allocate the acquired resource among the Ti...

Flash-based solid state storage devices (SSDs) are now becoming commonplace in server environments. In this paper, we consider the use of SSDs as a persistent second-tier cache for database systems. We argue that it is desirable to change the behavior of the database system’s buffer cache when a second-tier SSD cache is used, so that the buffer cache is aware of which pages are in the SSD cache...

Hierarchically-organized ensembles of shared memory multiprocessors possess a richer and more complex model of locality than previous generation multicomputers with single processor nodes. These dual-tier computers introduce many new factors into the program-mer's performance model. We present a methodology for implementing block-structured numerical applications on dual-tier computers, and a r...

The impact of high-speed rail (the following text is written as HSR) on regional economy has become an important research hotspot in the world. Using Difference Differences (DID) method, this paper analyzes influence HSR opening 223 cities from 2011 to 2018, considering time delay effect opening. After Propensity Score Matching (PSM-DID) method and counterfactual regression for robustness test,...

Application owners are typically concerned about getting the best performance at the lowest cost. When the workload demand for an application is dynamic, lowering the cost necessitates dynamic management of the hosting infrastructure (physical servers or virtual machines). An application deployment is often divided into multiple tiers. The frontend tier is usually stateless, and processes incom...

BACKGROUND Tissue repair in the adult mammalian liver occurs in two distinct processes, referred to as the first and second tiers of defense. We undertook to characterize the changes in molecular constituents of the extracellular matrix when hepatic progenitor cells (HPCs) respond in a second tier of defense to liver injury. RESULTS We used transcriptional profiling on rat livers responding b...