In most applications of DEA with internal structures in the literature, the models are designed to evaluate the performance of homogeneous Decision Making Units (DMUs). In many instances, however, DMUs operating in a similar technological environment may have different internal structures. In...

The existing literature on investment and reinsurance is limited to the study of continuous-time problems, while discrete-time problems are always ignored by researchers. In this study, we first discuss a multi-period investment and reinsurance optimization problem under the classical...

The existing cryptocurrency portfolio studies have relied heavily on historical asset returns and ignored the importance of the prediction information of asset returns, which leads to poor out-of-sample performance of the resulting portfolio strategies. To this end, we first crawl the tweets...

Traditional DEA models and nonlinear (diversification) DEA models are often used in performance evaluation of portfolios. However, the diversification models are usually very complicated to compute except the very basic models. And the classic DEA models still need to be further justified and...

In a question-answering system, learner generated content including asked and answered questions is a meaningful resource to capture learning interests. This paper proposes an approach based on question topic mining for revealing learners' concerned topics in real community question-answering...