Efficient, Optimal kk-Leader Selection for Coherent, One-Dimensional Formations

We study the problem of optimal leader selection in consensus networks with noisy relative information. The objective is to identify the set of $k$ leaders that minimizes the formation's deviation from the desired trajectory established by the leaders. An optimal leader set can be found by an exhaustive search over all possible leader sets; however, this approach is not scalable to large networks. In recent years, several works have proposed approximation algorithms to the $k$-leader selection problem, yet the question of whether there exists an efficient, non-combinatorial method to identify the optimal leader set remains open. This work takes a first step towards answering this question. We show that, in one-dimensional weighted graphs, namely path graphs and ring graphs, the $k$-leader selection problem can be solved in polynomial time (in both $k$ and the network size $n$). We give an $O(n^3)$ solution for optimal $k$-leader selection in path graphs and an $O(kn^3)$ solution for optimal $k$-leader selection in ring graphs.Comment: 7 pages, 5 figures, submitted to ECC1

Influence of Principal Work Styles and Behaviors on Teacher Commitment During School Reform in Georgia

Research was conducted to learn about the influence of leadership work styles and behavior patterns of three high school principals in northeast Georgia whose schools were undergoing reform through the No Child Left Behind Act of 2001. The study sought to identify specific work styles and behaviors that affected teacher commitment when implementing change during school reform initiatives. A mixed methods study of collecting and analyzing both quantitative and qualitative data was used in a case study involving three different high schools. Principals and their teachers responded to interview questions and survey questions to reveal patterns of work styles and behaviors used in the change process. The responses to both interview questions and surveys were analyzed to find common themes of work styles that influence teacher motivation towards implementation of school reform. Responses to the interview questions and surveys that supplemented observations made by the researcher added to the panoramic view of interactions between teachers and leaders in the change process. A convergence of both responses and various methods of data collection were conducted to reveal what motivates or prevents others to embrace change and implement reform structures. The findings indicated that principal work styles and behaviors affected teacher commitment. Interactions have been shown between three personality types of leadership and their respective teachers in acceptance of change within the school system. Leadership personalities which scored strongly in scale groupings that included achievement, self-actualizing, humanistic-encouraging and affilative were shown to foster positive and confident reactions from the teachers to commit, by contrast while the leadership personalities which scored strongly in the scale groupings that included approval, conventional-dependent and avoidance were shown to foster negative reactions in teacher commitment. Low confidence levels and insecurities over shadowed the support needed for teachers to embrace change. Therefore, it was recommended that districts seeking to promote change in specific schools, seek to appoint principals to those schools that possess the characteristics that foster positive teacher commitment to change

Cascading Behavior in Large Blog Graphs

How do blogs cite and influence each other? How do such links evolve? Does the popularity of old blog posts drop exponentially with time? These are some of the questions that we address in this work. Our goal is to build a model that generates realistic cascades, so that it can help us with link prediction and outlier detection. Blogs (weblogs) have become an important medium of information because of their timely publication, ease of use, and wide availability. In fact, they often make headlines, by discussing and discovering evidence about political events and facts. Often blogs link to one another, creating a publicly available record of how information and influence spreads through an underlying social network. Aggregating links from several blog posts creates a directed graph which we analyze to discover the patterns of information propagation in blogspace, and thereby understand the underlying social network. Not only are blogs interesting on their own merit, but our analysis also sheds light on how rumors, viruses, and ideas propagate over social and computer networks. Here we report some surprising findings of the blog linking and information propagation structure, after we analyzed one of the largest available datasets, with 45,000 blogs and ~ 2.2 million blog-postings. Our analysis also sheds light on how rumors, viruses, and ideas propagate over social and computer networks. We also present a simple model that mimics the spread of information on the blogosphere, and produces information cascades very similar to those found in real life

Studies on the dissociation reactions of [M + H]⁺ and [M + A]⁺ ions of small, model peptides using tandem mass spectrometry and fast atom bombardment ionization

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Bibliography: leaves 82-83.Not availabl

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