Incremental optimization of independent sets under the reconfiguration framework

Journal of Combinatorial Optimization - Suppose that we are given an independent set $$I_0$$ of a graph G, and an integer $$l\ge 0$$ . Then, we are asked to find an independent set of G having the...     

Are middle schoolers with diverse friends liked,disliked, or unnoticed - and by whom?

Having cross-ethnic friends in early adolescence is associated with more positive intergroup attitudes, but little is known about the social signaling function of the diversity of friends. The current study examined how the ethnic diversity of students’ friends in seventh grade is related to their social status (e.g., acceptance, rejection, and social impact) by eighth grade in multi-ethnic schools. It is hypothesized that friend diversity is (a) related to higher social status among ethnic out-group peers as it signals inclusiveness, but (b) related to lower in-group social status as diversity of friends may threaten the ethnic in-group. Utilizing a longitudinal sample of ethnically diverse youth (n = 4653) from 26 middle schools, the study capitalizes on outgoing friendship nominations in seventh grade and incoming acceptance and rejection nominations in eighth grade, while controlling for overall social status in grade seven. A novel index was used to calculate the diversity of youth's friend groups, and precise coding was done to retain biracial youth in the analytic sample. Results showed that having diverse friends was related to higher visibility (i.e., social impact) and greater acceptance from ethnic out-group members. In contrast, adolescents with diverse friend groups were less visible and less accepted by their in-group. Diversity of friends was not associated with out-group or in-group rejection. Findings highlight the importance of understanding how the composition of friend groups may signal intergroup attitudes and in-group solidarity in ways that have social status trade-offs among out- and in-group members.     

Understanding Patterns of Publishing Activity in Academic Research Occupations*

While it is widely understood that faculty in various disciplines tend to publish at different rates and in different forms, knowledge of these differences is too limited to facilitate systematically differentiated performance appraisal and reward systems. In this study, theory concerning knowledge production system characteristics as influences on individual performance is applied to academic research occupations using a classification scheme developed by Biglan [4]. Regression analysis is applied to a general (industry-wide) sample of United States faculty, with publishing patterns as performance measures. Each dimension of the classification scheme is found to have predictive validity. Output patterns are consistent with a conceptualization of research occupations in terms of (1) transformational/technological processes, (2) research mission, and (3) input/subject matter characteristics. The results offer a basis for generating disciplinary publishing norms and differentiated reward systems.