Ranking efficient DMUs using cooperative game theory

The problem of ranking Decision Making Units (DMUs) in Data Envelopment Analysis (DEA) has been widely studied in the literature. Some of the proposed approaches use cooperative game theory as a tool to perform the ranking. In this paper, we use the Shapley value of two different cooperative games in which the players are the efficient DMUs and the characteristic function represents the increase in the discriminant power of DEA contributed by each efficient DMU. The idea is that if the efficient DMUs are not included in the modified reference sample then the efficiency score of some inefficient DMUs would be higher. The characteristic function represents, therefore, the change in the efficiency scores of the inefficient DMUs that occurs when a given coalition of efficient units is dropped from the sample. Alternatively, the characteristic function of the cooperative game can be defined as the change in the efficiency scores of the inefficient DMUs that occurs when a given coalition of efficient DMUs are the only efficient DMUs that are included in the sample. Since the two cooperative games proposed are dual games, their corresponding Shapley value coincide and thus lead to the same ranking. The more an ef- ficient DMU impacts the shape of the efficient frontier, the higher the increase in the efficiency scores of the inefficient DMUs its removal brings about and, hence, the higher its contribution to the overall discriminant power of the method. The proposed approach is illustrated on a number of datasets from the literature and compared with existing methods

Preparing for an interdisciplinary future: A perspective from early-career researchers

Increasingly, research is moving towards more interdisciplinary endeavours. Effective collaboration between people from different disciplines is necessary to maximise the potential benefits of interdisciplinarity for future research activity. This paper analyses an approach to fostering the skills required for successful cross-disciplinary collaboration from the perspective of an interdisciplinary group of early-career researchers. Our reflection on how specially-designed encounters can help to shape future interdisciplinary research initiatives draws on the discussion of a four-day workshop, a post-event survey, and a review of other experiences. We conclude that interdisciplinary encounters are an effective means to support the development of future interdisciplinary researchers, with a major advantage of this approach being the opportunity for open communication. Depending on the organiser's aim, we distinguish between “cultivation” and “development” encounters. Among the multiple factors that produce successful interdisciplinary encounters, we found that selection of a theme, participants and location need to be tailored to the encounter's particular objectives. We recommend that funding bodies and other members of the research community should take note of the effectiveness of encounters to foster interdisciplinarity and generate space to develop more innovative and high-impact research that delivers solutions to the challenges facing humanity in the future

Laredo, Texas: Gateway Community on the Texas Borderlands, Archaeological and Historical Investigations for the Laredo City Toll Plaza

In July 1980, the Center for Archaeological Research, The University of Texas at San Antonio, conducted archaeological and historical investigations at sites designated as 41 WB 36,41 WB 37, and 41 WB 38, which are located in a residential district on the east side of the town of Laredo, Texas. These sites are represented by late historic foundations which were uncovered after a group of houses were razed to make way for a new toll bridge complex to facilitate international travel between the United States and the Republic of Mexico. A short history of Laredo and of the four house foundations excavated by the Center for Archaeological Research is presented in this report. The archaeological investigations of the structures and their associated artifacts are described and interpreted to provide a better understanding of sociocultural activities in Laredo from early historic times to the present

Linking nitrogen cycling transformations to microbial diversity in freshwater ecosystems

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