Many interesting theoretical problems arise from computer networks. In this thesis we will consider three of them: algorithms and data structures for problems involving distances in networks (in particular compact routing schemes, distance labels, and distance oracles), algorithms for wireless capacity and scheduling problems, and algorithms for optimizing iBGP overlays in autonomous systems on the Internet. While at first glance these problems may seem extremely different, they are similar in that they all attempt to look at a previously studied networking problem in new, more realistic frameworks. In other words, they are all as much about new models for old problems as they are about new algorithms. In this thesis we will define these models, design algorithms for them, and prove hardness and impossibility results for these three types of problems.

Thesis advisor: Rebecca Lowenhaupt / This qualitative study examined the organizational learning mechanisms (OLMs) used by school district educational leaders to improve the implementation of curriculum reform. This portion of the study focused on the OLMs used by central office boundary spanners to help school principals implement curriculum reform chosen by school district leaders. Drawing from interview and document data analysis, the results of this study indicated that OLMs used by central office boundary spanners are critical to the successful implementation of school reform. Examples of the OLMs used by central office boundary spanners included utilizing online technology and providing whole and small group support as well as individualized coaching to help school principals implement curriculum reform. Frequent communication, collaborative opportunities, and consistent messaging with school principals surfaced as the key OLM techniques used by central office boundary spanners to consistently improve the implementation of school reform. / Thesis (EdD) — Boston College, 2016. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

We study the complexity of finding so called spanner paths between arbitrary nodes in Euclidean graphs. We study both general Euclidean graphs and a special type of graphs called Integer Graphs. The problem is proven NP-complete for general Euclidean graphs with non-constant stretches (e.g. (2n)^(3/2) where n denotes the number of nodes in the graph). An algorithm solving the problem in O(2^(0.822n)) is presented. Integer graphs are simpler and for these special cases a better algorithm is presented. By using a partial order of so called Images the algorithm solves the spanner path problem using O(2^(c(\log n)^2)) time, where c is a constant depending only on the stretch.

Pour pouvoir assurer l’innovation, les alliances sont confrontées à un besoin de gestion des logiques d’exploration et d’exploitation, faisant naître le concept d’ambidextrie. La gestion de l’ambidextrie semble pourtant potentiellement portée par les alliance managers, acteurs aux frontières des organisations partenaires d’une alliance. Ils peuvent être qualifiés de boundary-spanners, mais leur rôle est peu connu. La recherche tente d’identifier les rôles de ces acteurs dans la gestion de l’ambidextrie dans les alliances. / Alliances have to deal with the dynamic of exploration and exploitation to innovate, which conducts to the ambidexterity concept. Managing ambidexterity is potentially led by the alliance managers who are boundary-spanners in alliances. However, there is a lack of knowledge concerning their roles. The research seeks to identify the roles of alliance managers as boundary-spanners in managing ambidexterity in alliances.

Syftet med undersökningen är att studera och öka förståelsen för relationen mellan bemanningsföretagens konsultchefer och deras kontaktpersoner vid kundföretagen. Genom att beskriva och analysera hur kontakten mellan konsultchefer och kundföretag ser ut är målet att besvara följande frågor: vem som ansvarar för vad, hur ser konsultchefen respektive kundföretaget på sin och den andra partens roll samt hur de ser på den överlappning som uppstår i ansvar och ledning av konsulterna. Undersökningen är kvalitativ och intervjuer har används för att samla in empiri. Fem personer intervjuades: tre konsultchefer på bemanningsföretag och två kontaktpersoner på kundföretag som hyr in personal av bemanningsföretag. I intervjuerna framkom att faktorer som har betydelse för hur relationen mellan konsultchef och hans eller hennes kontakt vid kundföretaget utvecklas är tid och volym på antalet konsulter som hyrs in. I vilken utsträckning konsultchef och kontaktpersonen vid kundföretaget delar ledarskap tycks hänga samman med om relationen över tid förblir formell eller om det tillkommer mer informellt utbyte. Undersökningen visar att när kundföretagen hyr in konsulter från samma bemanningsföretag under längre tid eller hyr in många konsulter finns större möjlighet till ömsesidigt utbyte i betydelsen att de kan diskutera fram beslut, dela på arbetsuppgifterna och ansvaret gentemot konsulterna samt byta erfarenheter som ökar lärandet. / The purpose of this study is to analyze and increase the understanding of the relationship between consultant managers in temporary work agencies (TWA) and their contacts in the client companies. The study aims to describe and analyze how they stay in contact with each other, who is responsible for what, how they view their own and the other's role and how they see the overlap that occurs in the responsibility and guidance of the agency workers. The study is qualitative and interviews were used to collect empirical data. Five people were interviewed: three consultant managers in TWA and two contacts who work in the client companies that hire TWA. The interviews revealed that the factors that are relevant to how the relationship between the consultant manager and his or her contact at the client company is developing are time and volume of the number of agency workers. The extent to which the consultant manager and contact person at the client company share leadership appears to be related to if the relationship over time remains a formality, or if there will be more informal exchange. The study shows that when the client companies hire agency workers from the same TWA for a longer time or hire many consultants, there are greater opportunities for mutual exchange in the sense that they can discuss the decisions, share tasks and responsibilities with regard to consultants, and share experiences that increase learning.

The purpose of this study is to investigate the ways in which members of interorganizational collaborations (IOCs) create and maintain the processes and structures of collaborative organizing. This research argues that IOCs are complex organizations that include ongoing communicative processes among individuals who act as collaborative members and constituent representatives. Specifically, this research seeks to explain how individual boundary spanners come to understand collaborative identities that create structures affecting actions and outcomes of the collaboration. Five research questions are posed using social identity theory as a guide to explore the data collected. The communication processes of IOC boundary spanners was investigated during a 13-month ethnographic field study, which included meeting observations, in-depth interviews, video stimulated recall, and document analysis. Overall, over 90% of the active members in the IOC were interviewed. Data was analyzed using the constant comparative method and organized by research question. Results indicate that boundary spanners in IOC use social identity to help orient and organize the diverse voices present within the collaboration. IOC members invoked group prototypes that created sub-groups within the IOC, thus allowing members with different goals for participation to find ways to justify membership. These prototypes also formed norms for communicating between members and created a collaborative environment that eventually led to organizational collapse. In addition, memberships within the IOC was constantly negotiated between members as the IOC worked towards certain goals. As sub-groups communicatively interacted with each other in the IOC, individuals would become more or less engaged in the collaborative process based on the successes and failures of the sub-group a boundary spanner has joined. Overall, this study helps us better understand how individuals within the IOC experience the collaboration and emphasize the importance of communication in collaborative processes. This study concludes with a discussion of the results and implications of the data for social identity theory, boundary spanner research and IOC research, as well as implications for practice. Limitations and future directions are also discussed. / text

Today we can see how companies are making significant investments in various methods and tools to access and utilize the users’ knowledge for the purpose of innovation efforts. What many highly innovative companies try to accomplish with these investments is to develop and establish sustained producer-user ecosystems. The aim of these ecosystems is often to encourage users to collaborate with each other and with the producer in order to generate innovations related to the offering of the producer. However, although these ecosystems are proven to create new innovation opportunities for companies, it has been shown that a close collaboration with many users brings about a number of challenges for companies. For example, it can be costly and time-consuming to establish and utilize large numbers of user relationships and it can be difficult to align the innovation interests of established producers with those of the users. Moreover, the fact that many innovating users have relationships to one another can contribute to conflicts of interests and established producers may have to balance stability and change within the ecosystem. Another challenge in the utilization of user relationships is that it is not only dependent on the direct interaction with users but also the internal dissemination and utilization of information related to the users’ needs. This dissemination can be problematic since it is costly and difficult to forward timely and reliable information about the users’ needs. Consequently, the aim of this thesis is to better understand how companies that are operating within sustained producer-user ecosystems can leverage user relationships for the purpose of innovation. The research forming the foundation for this thesis was carried out within two established medical technology companies that successfully had developed innovations within this type of ecosystems. Quantitative and qualitative data was collectedand a number of different analyses were conducted. The results reveal that these ecosystems can be understood as a system where direct and indirect user experiences are distributed among employees and users. This in turn implies that employees utilization of user relationships can be understood as a function of the extent to which employees knows and values the pertinence of their own as well as others direct and indirect user experiences as well as accessibility and cost of seeking user-information from other people. The results demonstrate that when companies experience high costs related to the acquisition of user experiences they may benefit from employing users to occupy boundary-spanning roles. However, the thesis reveals how the utilization of such boundary-spanning roles brings with it a number of organizational challenges. Moreover, an important aspect of success tends to be the utilization of relationships to so-called transformational users. These users experience problems with established producers' current products before the majority of users, they adopt new technologies earlier than their peers, and they cooperate with established producers for the purpose of transformation of a product field in order to obtain or maintain a central position within the ecosystem. Furthermore, the results reveal how established producers and users are jointly engaged in value creation through various collaborations. However, the results also indicate that the utilization of user relationships for innovation within these types of ecosystems is, to a large extent, a matter of managing tensions emerging within and around these collaborations. On a general level, this thesis points to the potential benefits of considering producer-user ecosystems as a comprehensive perspective, which may explain how companies gain and sustain a competitive edge, rather than one out of many approaches that companies can apply in order to leverage user relationships for innovation. / <p>QC 20140918</p>

In November 1953, the editor of the Manchester Guardian, AP Wadsworth, responded to Jodrell Bank Director Bernard Lovell regarding a complaint over an article that had appeared on the observatory's radio telescope project. Wadsworth understood there had been much collaboration between Lovell and his journalists in regard to the construction of the article and so the complaint suggested that there was 'far more to it (production) than appears on the surface'. Many scholars of science and the media point to the importance of uncovering the context of production from which popular science emerges in interactions between science and media actors. However, these and many other scholars also point to the difficulty of symmetrically unravelling the production context because of the complexities of such interactions and the diverse actors and agendas at play. To view and draw out these complexities, I employ the analytical flexibility and utility of space science as a lens because the production of popular space science was of interest, and valuable, to diverse scientific and media actors. I also use a broad and triangulated selection of primary sources, including from the often-elusive media context, to explore episodes of contingency where agendas and approaches are revealed. I hypothesise the notion of a 'common arena' to aid understandings of the context of production of science and the media. Within this common arena scientists, media professionals and science-mediating specialists met to negotiate the production of popular scientific representations. Scientific and media culture and science-mediating specialists sought authority over and identities within the arena through 'contributory expertise'. In such negotiations, popular scientific representations became a form of 'boundary object'. Across the middle of the twentieth century, and especially in the space age, popular space scientific representations were prestigious and high-profile and the subject of much negotiation. In many ways, the media gained much at the expense of science by redrawing the arena, exploiting science in the way that science sought to exploit the media. On reflection the arena is too simplistic a concept to support the rich narrative history and, in future, it is hoped, will be surpassed by a more constructivist encounter model that characterises interactions and developments at the science-media interface. Despite these limitations, two supplementary arguments emerge from the empirical application of the arena concept. Firstly, that the 'problem' of science and the media is historical and its origins long precede the political movement of the same name of the 1970s. In fact, the problem originated in the 1930s as soon as the traditional authority over the production arena enjoyed by scientific culture, and celebrity scientists such as cosmologist James Jeans, was challenged by media professionals. The Council of the British Interplanetary Society identified it, for example. Motivated by increased public demand for popular scientific material and intensifying competition among media industries, print and broadcasting media professionals extended their cultural authority over the common arena. This extension was facilitated because technological developments, such as satellite broadcasting, further restricted membership of the arena to those who understood the demands of media technique and were committed to serving the interests of audiences rather than science; in sociological terms arena and production authority was 'reduced' to media culture. Such developments reduced the ability of experts to directly address audiences and, thus, the influence of scientists over popular representations of science. In other words, mediation was a threat to the social authority of science. However, this problem was not mobilised into a movement because the relationship between scientific and media actors remained somewhat deferent and symbiotic. This fluidity allowed the likes of radio astronomer Lovell to continue to popularise, at least for a time. Another reason why the problem was not mobilised, and comprising the second supplementary argument, was the development of science-mediating specialists as 'boundary spanners'. Public eagerness for popular science, and the tensions between scientific and media culture for authority over its production, provided the opportunity for new social identities to emerge in the arena. Science writers such as JG Crowther, Ritchie Calder, and John Maddox, and science broadcasters such as Mary Adams, Aubrey Singer, and James McCloy, developed who mediated between, and were expert in and partisan to, both media and science; they were intercultural boundary spanners. However, the extension of the cultural authority of the media over the arena meant that membership of the arena became predicated on producing copy and programming that served the commercial interests of the media. Combined with, and reflecting, growing popular ambivalence with science, such pressures on science writers and broadcasters to actively challenge the social authority of science were the catalyst for the mobilisation of the problem movement by the scientific establishment. This movement sought to redraw production arena authority and re-establish the influence of scientists over popular scientific representations, as with Beagle 2.

<p>We start by slightly modifying the generic framework for solving online covering and packing linear programs (LP) proposed in the seminal work of Buchbinder and Naor (Mathematics of Operations Research, 34, 2009) to obtain efficient implementations in settings in which one has access to a separation oracle.</p> <p><br></p> <p>We then apply the generic framework to several online network connectivity problems with LP formulations, namely pairwise spanners and directed Steiner forests. Our results are comparable to the previous state-of-the-art results for these problems in the offline setting.</p> <p><br></p> <p>Further, we extend the generic frameworks to online optimization problems enhanced with <strong>machine-learning predictions</strong>. In particular, we present <strong>learning-augmented</strong> algorithms for online covering LPs and semidefinite programs (SDP), which outperform any optimal online algorithms when the prediction is accurate while maintaining reasonable guarantees when the prediction is misleading. Specifically, we obtain general online learning-augmented algorithms for covering LPs with fractional advice and general constraints and initiate the study of learning-augmented algorithms for covering SDPs.</p>

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