Interdependent Network Recovery Games

Recovery of interdependent infrastructure networks in the presence of catastrophic failure is crucial to the economy and welfare of society. Recently, centralized methods have been developed to address optimal resource allocation in postdisaster recovery scenarios of interdependent infrastructure systems that minimize total cost. In real-world systems, however, multiple independent, possibly noncooperative, utility network controllers are responsible for making recovery decisions, resulting in suboptimal decentralized processes. With the goal of minimizing recovery cost, a best-case decentralized model allows controllers to develop a full recovery plan and negotiate until all parties are satisfied (an equilibrium is reached). Such a model is computationally intensive for planning and negotiating, and time is a crucial resource in postdisaster recovery scenarios. Furthermore, in this work, we prove this best-case decentralized negotiation process could continue indefinitely under certain conditions. Accounting for network controllers' urgency in repairing their system, we propose an ad hoc sequential game-theoretic model of interdependent infrastructure network recovery represented as a discrete time noncooperative game between network controllers that is guaranteed to converge to an equilibrium. We further reduce the computation time needed to find a solution by applying a best-response heuristic and prove bounds on ε-Nash equilibrium, where ε depends on problem inputs. We compare best-case and ad hoc models on an empirical interdependent infrastructure network in the presence of simulated earthquakes to demonstrate the extent of the tradeoff between optimality and computational efficiency. Our method provides a foundation for modeling sociotechnical systems in a way that mirrors restoration processes in practice.     

Simultaneous Search

We introduce and solve a new class of “downward‐recursive” static portfolio choice problems. An individual simultaneously chooses among ranked stochastic options, and each choice is costly. In the motivational application, just one may be exercised from those that succeed. This often emerges in practice, such as when a student applies to many colleges or when a firm simultaneously tries several technologies. We show that such portfolio choice problems quite generally entail maximizing a submodular function of finite sets—which is NP‐hard in general. Still, we show that a greedy algorithm finds the optimal set, finding first the best singleton, then the best single addition to it, and so on. We show that the optimal choices are “less aggressive” than the sequentially optimal ones, but “more aggressive” than the best singletons. Also, the optimal set in general contains gaps. We provide some comparative statics results on the chosen set.     

Goffman's Interaction Order at the Margins: Stigma,Role, and Normalization in the Outreach Encounter

This article considers Goffman's conceptualization of interaction order at the margins of society in encounters between urban welfare workers and their clients. Observations from these encounters demonstrate practices relating to the situated management of stigma and identity, and the accomplishment of role within these service encounters. A reading of Goffman's theoretical contribution lies in revealing how social actors and social structures are realized in situ within the constraints of the interaction order sui generis. The article discusses three aspects of the outreach encounter, namely, (1) the accomplishment of role and motive, (2) the sequential phases of the outreach encounter, and (3) “the normalization ritual,” and introduces the concept of willful disattention.     

Towards a Sociology of Disclosure: The Case of Surgical Performance

Despite the increasingly widespread emphasis on the need for transparency in health‐care and elsewhere, there is limited evidence regarding the consequences of disclosing medical performance data. The evidence is disparate and has not been synthesised in a coherent way. This paper focuses on surgical performance, whose measurement is generally often seen as straight forward. It begins by outlining the context for understanding the publication of such data and then presents an analytical framework as a vehicle for conceptualising the nature of disclosure in surgery and health‐care more generally. The framework addresses key dimensions concerning one surgical specialty (cardiac surgery) and its relationship with a range of stakeholders in an English context. In particular, we examine the interaction between surgeons and between surgeons, patients, managers and policy‐makers. These relationships are framed in terms of choice and calculativeness, strategies and tactics, and trust, and need to be understood at micro, meso and macro levels. We conclude by considering how this framework provides a research agenda for a sociology of disclosure.     

Common factors influence bee foraging in urban and wildland landscapes

Bees are important flower-visiting insects that display differential occurrences at food resources throughout urban and wildland landscapes. This study examined the visitation rates and foraging patterns of eight taxonomic groups of bees that are common to California poppies, Eschscholzia californica, in both landscape types. Bee occurrence was documented in relation to floral resource characteristics (patch area, poppy coverage, and poppy density), local landscape characteristics (distance to the wildland-urban interface, distance to riparian areas, distance to green space, and land use), and regional landscape context (urban versus wildland). Similar abundance and richness measures were recorded at both urban and wildland poppy patches, but community composition varied in each landscape. Bumble bees were more abundant at poppies in the wildland whereas species in the family Halictidae (sweat bees) were more abundant at poppies within the urban landscape. Resource patch size and density consistently correlated with increased bee presence for all bee types foraging in the wildland. Individual patterns of occurrence in the urban landscape were somewhat divergent; the foraging dynamics of larger bodied-bees (Bombus vosnesenskii and Megachile species) correlated significantly with resource patch size and density, whereas smaller-bodied bees (family Halictidae and Andrena species) were influenced by landscape characteristics such as distance to the wildland-urban interface and distance to riparian areas. In summary, the surrounding landscape had an influence on community composition, but the magnitude of the floral resource present at a site and factors relating to foraging energetics were dominant drivers of local occurrence. These results suggest that management strategies that provide dense and abundant floral resources should be successful in attracting bees, irrespective of their location within the urban matrix.     

From Access to Opportunity: The Evolving Social Roles of Community Colleges

This paper looks at the social role played by community colleges, the students they serve, and some of the current challenges they face. Community colleges have always been multi-mission institutions and in recent decades have been leaders in enrolling students from diverse family backgrounds. “Nontraditional” students make up the majority of community college students. This paper looks at the diversity of students in terms of race and ethnicity, first-generation college-goers, and students who are academically underprepared. The paper concludes with a discussion of the strengths of the community college experience for students coming from diverse backgrounds.     

An intelligent workstation controller for integrated planning and scheduling of FMS cell

This paper presents an experimental design developed to determine a combination of robust planning and scheduling rules for an intelligent workstation controller (IWC). The IWC is used as part of the control system for an automated flexible manufacturing system. A three-level hierarchical control structure (shop, workstation and equipment)is adopted in order effectively to control a shop-floor. At the top level is a shop controller which receives orders and their associated manufacturing information, and manages interactions among workstations. The IWC defines and resolves the production control activities necessary to coordinate a group of equipment controllers so as to ensure the completion of orders. Specifically, the IWC is responsible for selecting a specific process routeing for each part, allocating resources, scheduling and coordinating the activities across the equipment, monitoring the progress of activities, detecting and recovering from errors, and preparing reports. These activities are accomplished using planning, scheduling, and execution functions. In order to demonstrate the effectiveness and robustness of the IWC, all the controllable and uncontrollable factors need to be identified and detailed. Controllable factors are those which are set by the controller and cannot be directly affected by the production environment. Uncontrollable factors are those which vary with the production environment and cannot be directly changed by the controller developer. The objective of the paper is to illustrate how a good set of controllable factors that dictate the IWC's effectiveness and robustness over various uncontrollable factors can be determined. Due to the number of possible combinations of all the factors, a complete validation of the effectiveness and robustness of the IWC is extremely time consuming and far beyond the scope of this paper. Therefore, a few planning and scheduling strategies are selected and a formal experiment is conducted. The experiment illustrates how significant performance dependencies for various planning and scheduling strategies can be identified.