Energy-Efficient Streaming Using Non-volatile Memory

The disk and the DRAM in a typical mobile system consume a significant fraction (up to 30%) of the total system energy. To save on storage energy, the DRAM should be small and the disk should be spun down for long periods of time. We show that this can be achieved for predominantly streaming workloads by connecting the disk to the DRAM via a large non-volatile memory (NVM). We refer to this as the NVM-based architecture (NVMBA); the conventional architecture with only a DRAM and a disk is referred to as DRAMBA. The NVM in the NVMBA acts as a traffic reshaper from the disk to the DRAM. The total system costs are balanced, since the cost increase due to adding the NVM is compensated by the decrease in DRAM cost. We analyze the energy saving of NVMBA, with NAND flash memory serving as NVM, relative to DRAMBA with respect to (1) the streaming demand, (2) the disk form factor, (3) the best-effort provision, and (4) the stream location on the disk. We present a worst-case analysis of the reliability of the disk drive and the flash memory, and show that a small flash capacity is sufficient to operate the system over a year at negligible cost. Disk lifetime is superior to flash, so that is of no concern

When Things Matter: A Data-Centric View of the Internet of Things

With the recent advances in radio-frequency identification (RFID), low-cost wireless sensor devices, and Web technologies, the Internet of Things (IoT) approach has gained momentum in connecting everyday objects to the Internet and facilitating machine-to-human and machine-to-machine communication with the physical world. While IoT offers the capability to connect and integrate both digital and physical entities, enabling a whole new class of applications and services, several significant challenges need to be addressed before these applications and services can be fully realized. A fundamental challenge centers around managing IoT data, typically produced in dynamic and volatile environments, which is not only extremely large in scale and volume, but also noisy, and continuous. This article surveys the main techniques and state-of-the-art research efforts in IoT from data-centric perspectives, including data stream processing, data storage models, complex event processing, and searching in IoT. Open research issues for IoT data management are also discussed

Parsing consumption preferences of music streaming audiences

As demands for insights on music streaming listeners continue to grow, scientists and industry analysts face the challenge to comprehend a mutated consumption behavior, which demands a renewed approach to listener typologies. This study aims to determine how audience segmentation can be performed in a time-relevant and replicable manner. Thus, it interrogates which parameters best serve as indicators of preferences to ultimately assist in delimiting listener segments. Accordingly, the primary objective of this research is to develop a revised typology that classifies music streaming listeners in the light of the progressive phenomenology of music listening. The hypothesis assumes that this could be solved by positioning listeners – rather than products – at the center of streaming analysis and supplementing sales- with user-centered metrics. The empirical research of this paper was based on grounded theories, enriched by analytical case studies. For this purpose, behavioral and psychological research results were interconnected with market analysis and streaming platform usage data. Analysis of the results demonstrates that a concatenation of multi-dimensional data streams facilitates the derivation of a typology that is applicable to varying audience pools. The findings indicate that for the delimitation of listener types, the motivation, and listening context are essential key constituents. Since these variables demand insights that reach beyond existing metrics, descriptive data points relating to the listening process are subjoined. Ultimately, parameter indexation results in listener profiles that offer novel access points for investigations, which make imperceptible, interdisciplinary correlations tangible. The framework of the typology can be consulted in analytical and creational processes. In this respect, the results of the derived analytical approach contribute to better determine and ultimately satisfy listener preferences.Während die Nachfrage nach Erkenntnissen über Musik-Streaming-Hörer kontinuierlich steigt, stehen Wissenschaftler sowie Industrieanalysten einem geänderten Konsumptions- verhalten gegenüber, das eine überarbeitete Hörertypologie fordert. Die vorliegende Studie erörtert, wie eine Hörersegmentierung auf zeitgemäße und replizierbare Weise umgesetzt werden kann. Demnach beschäftigt sie sich mit der Frage, welche Parameter am besten als Indikatoren für Hörerpräferenzen dienen und wie diese zur Abgrenzung der Publikumsseg- mente beitragen können. Dementsprechend ist es das primäre Ziel dieser Forschung, eine überarbeitete Typologie aufzustellen, die Musik-Streaming-Hörer in Anbetracht der progressiven Erscheinungsform des Musikhörens klassifiziert. Die Hypothese nimmt an, dass dies realisierbar ist, wenn der Hörer – anstelle von Produkten – im Zentrum der Streaming-Analyse steht und absatzzen- trierte durch hörerzentrierte Messungen ergänzt werden. Die empirische Forschung basiert auf systematischen Theorien, untermauert durch analytische Fallbeispiele. Hierfür werden psychologische und verhaltenswissenschaftliche Forschungserkenntnisse mit Marktanalysen und Nutzerdaten von Musikstreaming-Portalen fusioniert. Die Analyse der Ergebnisse verdeutlicht, dass eine Verkettung von multidimensionalen Rohdaten die Erhebung einer Typologie ermöglicht, die auf mehrere Hörergruppen anwend- bar ist. Die Befunde signalisieren, dass die Hörmotivation und der Hörkontext bei der Abgrenzung der Publikumstypen Schlüsselelemente darstellen. Da diese Variablen spezifis- che Kenntnisse fordern, die über vorliegende Kennzahlen hinausgehen, werden deskriptive Datenpunkte über den Hörvorgang ergänzt. Letztlich, resultiert die Indexierung der Pa- rameter in Hörerprofilen, die neue Zugangspunkte für Untersuchungen bieten, die nicht ersichtliche, interdisziplinäre Korrelationen greifbar machen. Das Gerüst der Hörertypologie kann sowohl in Erstellungs- als auch in Analyseprozessen herangezogen werden. Somit tragen die Ergebnisse der entwickelten Analysemethode zum Verständnis und letztlich zur Erfüllung von Hörerpräferenzen bei

Parsing consumption preferences of music streaming audiences

As demands for insights on music streaming listeners continue to grow, scientists and industry analysts face the challenge to comprehend a mutated consumption behavior, which demands a renewed approach to listener typologies. This study aims to determine how audience segmentation can be performed in a time-relevant and replicable manner. Thus, it interrogates which parameters best serve as indicators of preferences to ultimately assist in delimiting listener segments. Accordingly, the primary objective of this research is to develop a revised typology that classifies music streaming listeners in the light of the progressive phenomenology of music listening. The hypothesis assumes that this could be solved by positioning listeners – rather than products – at the center of streaming analysis and supplementing sales- with user-centered metrics. The empirical research of this paper was based on grounded theories, enriched by analytical case studies. For this purpose, behavioral and psychological research results were interconnected with market analysis and streaming platform usage data. Analysis of the results demonstrates that a concatenation of multi-dimensional data streams facilitates the derivation of a typology that is applicable to varying audience pools. The findings indicate that for the delimitation of listener types, the motivation, and listening context are essential key constituents. Since these variables demand insights that reach beyond existing metrics, descriptive data points relating to the listening process are subjoined. Ultimately, parameter indexation results in listener profiles that offer novel access points for investigations, which make imperceptible, interdisciplinary correlations tangible. The framework of the typology can be consulted in analytical and creational processes. In this respect, the results of the derived analytical approach contribute to better determine and ultimately satisfy listener preferences.Während die Nachfrage nach Erkenntnissen über Musik-Streaming-Hörer kontinuierlich steigt, stehen Wissenschaftler sowie Industrieanalysten einem geänderten Konsumptions- verhalten gegenüber, das eine überarbeitete Hörertypologie fordert. Die vorliegende Studie erörtert, wie eine Hörersegmentierung auf zeitgemäße und replizierbare Weise umgesetzt werden kann. Demnach beschäftigt sie sich mit der Frage, welche Parameter am besten als Indikatoren für Hörerpräferenzen dienen und wie diese zur Abgrenzung der Publikumsseg- mente beitragen können. Dementsprechend ist es das primäre Ziel dieser Forschung, eine überarbeitete Typologie aufzustellen, die Musik-Streaming-Hörer in Anbetracht der progressiven Erscheinungsform des Musikhörens klassifiziert. Die Hypothese nimmt an, dass dies realisierbar ist, wenn der Hörer – anstelle von Produkten – im Zentrum der Streaming-Analyse steht und absatzzen- trierte durch hörerzentrierte Messungen ergänzt werden. Die empirische Forschung basiert auf systematischen Theorien, untermauert durch analytische Fallbeispiele. Hierfür werden psychologische und verhaltenswissenschaftliche Forschungserkenntnisse mit Marktanalysen und Nutzerdaten von Musikstreaming-Portalen fusioniert. Die Analyse der Ergebnisse verdeutlicht, dass eine Verkettung von multidimensionalen Rohdaten die Erhebung einer Typologie ermöglicht, die auf mehrere Hörergruppen anwend- bar ist. Die Befunde signalisieren, dass die Hörmotivation und der Hörkontext bei der Abgrenzung der Publikumstypen Schlüsselelemente darstellen. Da diese Variablen spezifis- che Kenntnisse fordern, die über vorliegende Kennzahlen hinausgehen, werden deskriptive Datenpunkte über den Hörvorgang ergänzt. Letztlich, resultiert die Indexierung der Pa- rameter in Hörerprofilen, die neue Zugangspunkte für Untersuchungen bieten, die nicht ersichtliche, interdisziplinäre Korrelationen greifbar machen. Das Gerüst der Hörertypologie kann sowohl in Erstellungs- als auch in Analyseprozessen herangezogen werden. Somit tragen die Ergebnisse der entwickelten Analysemethode zum Verständnis und letztlich zur Erfüllung von Hörerpräferenzen bei

Role based behavior analysis

Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2009Nos nossos dias, o sucesso de uma empresa depende da sua agilidade e capacidade de se adaptar a condições que se alteram rapidamente. Dois requisitos para esse sucesso são trabalhadores proactivos e uma infra-estrutura ágil de Tecnologias de Informacão/Sistemas de Informação (TI/SI) que os consiga suportar. No entanto, isto nem sempre sucede. Os requisitos dos utilizadores ao nível da rede podem nao ser completamente conhecidos, o que causa atrasos nas mudanças de local e reorganizações. Além disso, se não houver um conhecimento preciso dos requisitos, a infraestrutura de TI/SI poderá ser utilizada de forma ineficiente, com excessos em algumas áreas e deficiências noutras. Finalmente, incentivar a proactividade não implica acesso completo e sem restrições, uma vez que pode deixar os sistemas vulneráveis a ameaças externas e internas. O objectivo do trabalho descrito nesta tese é desenvolver um sistema que consiga caracterizar o comportamento dos utilizadores do ponto de vista da rede. Propomos uma arquitectura de sistema modular para extrair informação de fluxos de rede etiquetados. O processo é iniciado com a criação de perfis de utilizador a partir da sua informação de fluxos de rede. Depois, perfis com características semelhantes são agrupados automaticamente, originando perfis de grupo. Finalmente, os perfis individuais são comprados com os perfis de grupo, e os que diferem significativamente são marcados como anomalias para análise detalhada posterior. Considerando esta arquitectura, propomos um modelo para descrever o comportamento de rede dos utilizadores e dos grupos. Propomos ainda métodos de visualização que permitem inspeccionar rapidamente toda a informação contida no modelo. O sistema e modelo foram avaliados utilizando um conjunto de dados reais obtidos de um operador de telecomunicações. Os resultados confirmam que os grupos projectam com precisão comportamento semelhante. Além disso, as anomalias foram as esperadas, considerando a população subjacente. Com a informação que este sistema consegue extrair dos dados em bruto, as necessidades de rede dos utilizadores podem sem supridas mais eficazmente, os utilizadores suspeitos são assinalados para posterior análise, conferindo uma vantagem competitiva a qualquer empresa que use este sistema.In our days, the success of a corporation hinges on its agility and ability to adapt to fast changing conditions. Proactive workers and an agile IT/IS infrastructure that can support them is a requirement for this success. Unfortunately, this is not always the case. The user’s network requirements may not be fully understood, which slows down relocation and reorganization. Also, if there is no grasp on the real requirements, the IT/IS infrastructure may not be efficiently used, with waste in some areas and deficiencies in others. Finally, enabling proactivity does not mean full unrestricted access, since this may leave the systems vulnerable to outsider and insider threats. The purpose of the work described on this thesis is to develop a system that can characterize user network behavior. We propose a modular system architecture to extract information from tagged network flows. The system process begins by creating user profiles from their network flows’ information. Then, similar profiles are automatically grouped into clusters, creating role profiles. Finally, the individual profiles are compared against the roles, and the ones that differ significantly are flagged as anomalies for further inspection. Considering this architecture, we propose a model to describe user and role network behavior. We also propose visualization methods to quickly inspect all the information contained in the model. The system and model were evaluated using a real dataset from a large telecommunications operator. The results confirm that the roles accurately map similar behavior. The anomaly results were also expected, considering the underlying population. With the knowledge that the system can extract from the raw data, the users network needs can be better fulfilled, the anomalous users flagged for inspection, giving an edge in agility for any company that uses it