Mixed-Integer Programming for a Class of Robust Submodular Maximization Problems

We consider robust submodular maximization problems (RSMs), where given a set of $m$ monotone submodular objective functions, the robustness is with respect to the worst-case (scaled) objective function. The model we consider generalizes two variants of robust submodular maximization problems in the literature, depending on the choice of the scaling vector. On one hand, by using unit scaling, we obtain a usual robust submodular maximization problem. On the other hand, by letting the scaling vector be the optimal objective function of each individual (NP-hard) submodular maximization problem, we obtain a second variant. While the robust version of the objective is no longer submodular, we reformulate the problem by exploiting the submodularity of each function. We conduct a polyhedral study of the resulting formulation and provide conditions under which the submodular inequalities are facet-defining for a key mixed-integer set. We investigate several strategies for incorporating these inequalities within a delayed cut generation framework to solve the problem exactly. For the second variant, we provide an algorithm to obtain a feasible solution along with its optimality gap. We apply the proposed methods to a sensor placement optimization problem in water distribution networks using real-world datasets to demonstrate the effectiveness of the methods

2-(1H-Pyrrolo­[2,3-b]pyridin-2-yl)pyridine

In the title compound, C12H9N3, the dihedral angle between the pyridine and aza­indole rings is 6.20 (2)°. In the crystal, pairs of N—H⋯N hydrogen bonds link mol­ecules into inversion dimers

The Value of Academic Directors to Stakeholders: Evidence on Corporate Social Responsibility Reporting

This study explores the regulatory setting in Taiwan and examines the association between academic directors and corporate social responsibility (CSR) reporting. We find that firms with academic directors on the board are more likely to issue a stand-alone CSR report and obtain third-party assurance on their CSR reports. We also find a positive association between CSR reporting and academic directors with industry expertise. Further cross-sectional analyses indicate that the positive relation between academic directors (and their industry expertise) and CSR reporting is stronger in firms with higher growth, greater institutional ownership, and lower control-ownership divergence. Our findings that the presence of academic directors can promote better sustainability reporting suggest that academic directors contribute not only to shareholder value but also to wider stakeholder interests

THE ANTECEDENTS OF AN INDIVIDUAL\u27S COMMITMENTS TOWARD CONTINUOUSLY USING SOCIAL NETWORK SITE

The Social network sites (SNS) has been rapid diffusion around the world. With the increasing importance of SNS, continuance intention also becomes a popular issue in the SNS context. SNS providers have to maintain better relationships with users and make individuals continue to use their sites. Based on this phenomenon, the objective of this study is to gain a better understanding of the continuance intention of SNS through examining the effects of commitments. Specifically, followed Meyer and Allen’s three-component model of commitment, we develop a theoretical model to understand the factors that influence normative, affective and continued commitment and investigate the effects of commitments on continuance intention in the SNS context. Through a survey-based empirical investigation, we anticipate the results to enhance our existing knowledge on continuance intention in the SNS context