A Fast Algorithm for Source-Wise Round-Trip Spanners

In this paper, we study the problem of efficiently constructing source-wise round-trip spanners in weighted directed graphs. For a source vertex set $S\subseteq V$ in a digraph $G(V,E)$, an $S$-source-wise round-trip spanner of $G$ of stretch $k$ is a subgraph $H$ of $G$ such that for every $u\in S,v\in V$, the round-trip distance between $u$ and $v$ in $H$ is at most $k$ times of the original distance in $G$. We show that, for a digraph $G(V,E)$ with $n$ vertices, $m$ edges and nonnegative edge weights, an $s$-sized source vertex set $S\subseteq V$ and a positive integer $k$, there exists an algorithm, in time $O(ms^{1/k}\log^5n)$, with high probability constructing an $S$-source-wise round-trip spanner of stretch $O(k\log n)$ and size $O(ns^{1/k}\log^2n)$. Compared with the state of the art for constructing source-wise round-trip spanners, our algorithm significantly improves their construction time $\Omega(\min\{ms,n^\omega\})$ (where $\omega \in [2,2.373)$ and 2.373 is the matrix multiplication exponent) to nearly linear $O(ms^{1/k}\log^5n)$, while still keeping a spanner stretch $O(k\log n)$ and size $O(ns^{1/k}\log^2n)$, asymptotically similar to their stretch $2k+\epsilon$ and size $O((k^2/\epsilon)ns^{1/k}\log(nw))$, respectively

Communication-Optimal Distributed Dynamic Graph Clustering

We consider the problem of clustering graph nodes over large-scale dynamic graphs, such as citation networks, images and web networks, when graph updates such as node/edge insertions/deletions are observed distributively. We propose communication-efficient algorithms for two well-established communication models namely the message passing and the blackboard models. Given a graph with $n$ nodes that is observed at $s$ remote sites over time $[1,t]$, the two proposed algorithms have communication costs $\tilde{O}(ns)$ and $\tilde{O}(n+s)$ ($\tilde{O}$ hides a polylogarithmic factor), almost matching their lower bounds, $\Omega(ns)$ and $\Omega(n+s)$, respectively, in the message passing and the blackboard models. More importantly, we prove that at each time point in $[1,t]$ our algorithms generate clustering quality nearly as good as that of centralizing all updates up to that time and then applying a standard centralized clustering algorithm. We conducted extensive experiments on both synthetic and real-life datasets which confirmed the communication efficiency of our approach over baseline algorithms while achieving comparable clustering results.Comment: Accepted and to appear in AAAI'1

Understanding the forces that affect the market orientation of three diverse teams : a mixed-methods, longitudinal study

D.B.A. ThesisPrior research has shown a relationship between market orientation and business performance. Relatively little research, however, has focused on antecedents to market orientation. Additionally, insufficient market orientation research has been conducted at the team level, specifically on new product development and customer teams, the groups closest to new product launches, which are critical to organizational success. There is also insufficient research on how a group’s market orientation might change over time. Lastly, most past studies have used data collected from one or two employees to assess the market orientation of the entire organization. It is not clear how perceptions of market orientation might differ among employees, based on their role within the organization. This research seeks to address these gaps. This research presents the findings from data collected over three years from three teams in the same organization. The teams’ market orientation is viewed through three different lenses: the MKTOR scale developed by Narver and Slater, one-on-one interviews, and network analysis. The research presents a substantive theory that explains the data collected from all three teams and from all three data sources. The data suggests that market orientation is the coordinated effort to gather, disseminate, and respond to information in order to maintain and increase business with the customer, thus supporting an integration of the two primary conceptualizations of market orientation. Throughout the process the team faces ambiguity on many fronts, and the team must deliberately manage this ambiguity in order to be successful. Managing ambiguity, however, is not the same thing as eliminating ambiguity as resource limitations and team size restrict how much ambiguity can be removed. Clarifying communications, including developing a shared understanding of customer targets, serve to remove ambiguity in the team

Building an Ethical Small Group (Chapter 9 of Meeting the Ethical Challenges of Leadership)

This chapter examines ethical leadership in the small-group context. To help create groups that brighten rather than darken the lives of participants, leaders must foster individual ethical accountability among group members, ensure ethical group interaction, avoid moral pitfalls, and establish ethical relationships with other groups. In his metaphor of the leader\u27s light or shadow, Parker Palmer emphasizes that leaders shape the settings or contexts around them. According to Palmer, leaders are people who have an unusual degree of power to create the conditions under which other people must live and move and have their being, conditions that can either be as illuminating as heaven or as shadowy as hell. 1 In this final section of the text, I\u27ll describe some of the ways we can create conditions that illuminate the lives of followers in small-group, organizational, global, and crisis settings. Shedding light means both resisting and exerting influence. We must fend off pressures to engage in unethical behavior while actively seeking to create healthier moral environments

Annual reports of the town officers, town of Francestown, New Hampsire, year ending December 31, 1946, reports of the school district officers, June 30, 1946.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

Fifteenth annual report of the municipal government of the city of Franklin, for the financial year 1909.

This is an annual report containing vital statistics for a town/city in the state of New Hampshire

AT THE BASE OF THE BRIDGE: A CASE STUDY OF BOUNDARY SPANNING BY MEMBERS OF A UNIVERSITY'S PRESIDENTIAL LEADERSHIP TEAM

This study examined the extent to which presidential leadership teams in institutions of higher education realize their goal of helping college and university presidents with decision making. The literatures on leadership teams in higher education and in other contexts suggest that these teams have promise for helping presidents manage complex internal and external demands. However, empirical research on these teams has been limited. This dissertation addresses that research gap with an in-depth qualitative case study of one presidential leadership team. I drew on management and organizational behavior literature to conceptualize team members as boundary spanners who operated between the president and the rest of the university and the university's external environment. This literature suggested team members would help manage both information and political relationships. I then used concepts from the new institutionalism in sociology to help me identify those conditions that might help or hinder team members' boundary-spanning activities. My primary data sources were interviews, extensive observations, and document analysis. I found that the university president in this case intended for his team to operate as boundary spanners who would manage information and political relationships, but that team members' engagement in these intended activities varied. I found that most team members helped with information management only occasionally and focused their efforts primarily on political activities outside of the institution. However, a core group frequently engaged in these activities. The variation in participation seemed to depend on whether individuals came with the capacity and orientation to engage in these roles. The team setting itself did not provide basic structures or resources to encourage these forms of participation among all members. This study suggests the need to apply additional frameworks and methods to illuminate other dimensions of teamwork in presidential leadership teams. In practice, this study shows that in order for individuals to fulfill boundary-spanning functions, the team setting may need to foster particular dynamics and provide certain structures that enable information management. These structures range from the provision of basic meeting agendas and facilitation to models of how to engage in information and political management activities