Survey of Spectrum Sharing for Inter-Technology Coexistence

Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open to multiple technologies. These will, in turn, increase the level of interference and also result in more complex inter-technology interactions, which will need to be managed through spectrum sharing mechanisms. Consequently, novel spectrum sharing mechanisms should be designed to allow spectrum access for multiple technologies, while efficiently utilizing the spectrum resources overall. Importantly, it is not trivial to design such efficient mechanisms, not only due to technical aspects, but also due to regulatory and business model constraints. In this survey we address spectrum sharing mechanisms for wireless inter-technology coexistence by means of a technology circle that incorporates in a unified, system-level view the technical and non-technical aspects. We thus systematically explore the spectrum sharing design space consisting of parameters at different layers. Using this framework, we present a literature review on inter-technology coexistence with a focus on wireless technologies with equal spectrum access rights, i.e. (i) primary/primary, (ii) secondary/secondary, and (iii) technologies operating in a spectrum commons. Moreover, we reflect on our literature review to identify possible spectrum sharing design solutions and performance evaluation approaches useful for future coexistence cases. Finally, we discuss spectrum sharing design challenges and suggest future research directions

The economics of copyright law: a stocktake of the literature

This article is a survey of publications by economists writing on copyright law. It begins with a general overview of how economists analyse these questions; the distinction is made between the economics of copying and the economic aspects of copyright law as analysed in law and economics. It then continues with sections on research on the effects of copying and downloading and the effects of unauthorised use (‘piracy’) and ends with an overall evaluation of the economics of copyright in the light of recent technological changes. Economists have always been, and still are, somewhat sceptical about copyright and question what alternatives there are to it. On balance, most accept the role of copyright law in the creative industries while urging caution about its becoming too strong. And although European authors’ rights are different in legal terms from the Anglo-American copyright, the economic analysis of these laws is essentially the same

Determinants of science-based cooperation: evidence in a sample of small and micro firms

We study the determining factors of cience-based cooperation in the case of small and micro firms. In this research, we propose an analytical framework based on the resource-based view of the firm and we identify a set of organisational characteristics, which we classify as internal, external and structural factors. Each factor can be linked to at least one reason, from the firm¿s point of view, to cooperate with universities and public research centres. Each reason can, in turn, be used as an indicator of a firm¿s organisational needs or organisational capacities. In order to validate the theoretical model, we estimate a logistic regression that models the propensity to participate in science-based cooperation activities within a sample of 285 small and micro firms located in Barcelona. The results show the key role played by the absorptive capacity of new and small companies.Se estudian los factores determinantes de la ciencia basada en la cooperación en el caso de las pequeñas empresas y microempresas. En esta investigación, se propone un análisis marco basado en el punto de vista de los recursos de la empresa y que identifica un conjunto de características de la organización, que podemos clasificar como factores internos, externos y estructurales. Cada factor puede estar relacionado por lo menos con una razón, desde el punto de vista de la empresa, para cooperar con las universidades y centros públicos de investigación. Cada una de ellas, a su vez, se utilizará como un indicador de las necesidades organizativas de la empresa o su capacidad de organización. Con el fin de validar el modelo teórico, se estima una regresión logística que muestra la propensión a participar en las actividades de cooperación basadas en la ciencia de una muestra de 285 empresas pequeñas y microempresas ubicadas en Barcelona. Los resultados muestran el papel clave desempeñado por la capacidad de absorción de las empresas nuevas y pequeñas.S'estudien els factors determinants de la ciència basada en la cooperació en el cas de les petites empreses i microempreses. Aquesta investigació es proposa una anàlisi marc basada en el punt de vista dels recursos de l'empresa i que identifica un conjunt de característiques de la organització, que podem classificar amb factors interns, externs i estructurals. Cada factor pot estar relacionat com a mínim amb una raó, des del punt de vista de l'empresa, per cooperar amb universitats i centres públics d'investigació. Cada una d'aquestes, al seu torn, s'utilitzarà com un indicador de les necessitats organitzatives de l'empresa o la seva capacitat d'organització. Amb l'objectiu de validar el model teòric, es preveu una regressió logística que mostra la tendència a participar en les activitats de cooperació basades en la ciència d'una mostra de 285 empreses petites i microempreses ubicades a Barcelona. Els resultats mostren el paper clau dut a terme per la capacitat d'absorció de les noves i petites empreses

Storage Solutions for Big Data Systems: A Qualitative Study and Comparison

Big data systems development is full of challenges in view of the variety of application areas and domains that this technology promises to serve. Typically, fundamental design decisions involved in big data systems design include choosing appropriate storage and computing infrastructures. In this age of heterogeneous systems that integrate different technologies for optimized solution to a specific real world problem, big data system are not an exception to any such rule. As far as the storage aspect of any big data system is concerned, the primary facet in this regard is a storage infrastructure and NoSQL seems to be the right technology that fulfills its requirements. However, every big data application has variable data characteristics and thus, the corresponding data fits into a different data model. This paper presents feature and use case analysis and comparison of the four main data models namely document oriented, key value, graph and wide column. Moreover, a feature analysis of 80 NoSQL solutions has been provided, elaborating on the criteria and points that a developer must consider while making a possible choice. Typically, big data storage needs to communicate with the execution engine and other processing and visualization technologies to create a comprehensive solution. This brings forth second facet of big data storage, big data file formats, into picture. The second half of the research paper compares the advantages, shortcomings and possible use cases of available big data file formats for Hadoop, which is the foundation for most big data computing technologies. Decentralized storage and blockchain are seen as the next generation of big data storage and its challenges and future prospects have also been discussed

Evaluating an online learning community: Intellectual, social and emotional development and transformations.

Developing online learning communities is a promising pedagogical approach in online learning contexts for adult tertiary learners, but it is no easy task. Understanding how learning communities are formed and evaluating their efficacy in supporting teaching-learning involves a complex set of issues that have a bearing on the design and facilitation of successful online learning experiences. This paper presents findings of a case study of a semester-long online graduate course designed to facilitate a learning community at a New Zealand tertiary institution. It adopts a sociocultural analytical framework and argues for a multiple developmental analytical approach to evaluating learning that considers lecturer and student intellectual, social and emotional development and transformations. Implications are presented for online lecturers, course designers and institutional administrators

Evaluating Collaborative Information Seeking Interfaces with a Search-Oriented Inspection Method and Re-framed Information Seeking Theory

Despite the many implicit references to the social contexts of search within Information Seeking and Retrieval research, there has been relatively little work that has specifically investigated the additional requirements for collaborative information seeking interfaces. Here, we re-assess a recent analytical inspection framework, designed for individual information seeking, and then apply it to evaluate a recent collaborative information seeking interface: SearchTogether. The framework was built upon two models of solitary information seeking, and so as part of the re-assessment we first re-frame the models for collaborative contexts. We re-frame a model of search tactics, providing revised definitions that consider known collaborators. We then re-frame a model of user profiles to analyse support for different group dynamics. After presenting an analysis of SearchTogether, we reflect on its accuracy, showing that the framework identified 8 known truths, 8 new insights, and no known-to-be-untrue insights into the design. We conclude that the framework a) can still be applied to collaborative information seeking interfaces; b) can successfully produce additional requirements for collaborative information seeking interfaces; and c) can successfully model different dynamics of collaborating searchers