353 research outputs found

    On the Comparisons of Decorrelation Approaches for Non-Gaussian Neutral Vector Variables

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    three different approaches for localization in a corridor environment by means of an ultrasonic wide beam

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    In this paper the authors present three methods to detect the position and orientation of an observer, such as a mobile robot, with respect to a corridor wall. They use an inexpensive sensor to spread a wide ultrasonic beam. The sensor is rotated by means of an accurate servomotor in order to propagate ultrasonic waves towards a regular wall. Whatever the wall material may be the scanning surface appears to be an acoustic reflector as a consequence of low air impedance. The realized device is able to give distance information in each motor position and thus permits the derivation of a set of points as a ray trace-scanner. The dataset contains points lying on a circular arc and relating to strong returns. Three different approaches are herein considered to estimate both the slope of the wall and its minimum distance from the sensor. Slope and perpendicular distance are the parameters of a target plane, which may be calculated in each observer's position to predict its new location. Experimental tests and simulations are shown and discussed by scanning from different stationary locations. They allow the appreciation of the effectiveness of the proposed approaches

    A review on data fusion in multimodal learning analytics and educational data mining

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    The new educational models such as smart learning environments use of digital and context-aware devices to facilitate the learning process. In this new educational scenario, a huge quantity of multimodal students' data from a variety of different sources can be captured, fused, and analyze. It offers to researchers and educators a unique opportunity of being able to discover new knowledge to better understand the learning process and to intervene if necessary. However, it is necessary to apply correctly data fusion approaches and techniques in order to combine various sources of multimodal learning analytics (MLA). These sources or modalities in MLA include audio, video, electrodermal activity data, eye-tracking, user logs, and click-stream data, but also learning artifacts and more natural human signals such as gestures, gaze, speech, or writing. This survey introduces data fusion in learning analytics (LA) and educational data mining (EDM) and how these data fusion techniques have been applied in smart learning. It shows the current state of the art by reviewing the main publications, the main type of fused educational data, and the data fusion approaches and techniques used in EDM/LA, as well as the main open problems, trends, and challenges in this specific research area

    Where does Computational Media Aesthetics Fit?

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    Communicating Uncertainty in Digital Humanities Visualization Research

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    Due to their historical nature, humanistic data encompass multiple sources of uncertainty. While humanists are accustomed to handling such uncertainty with their established methods, they are cautious of visualizations that appear overly objective and fail to communicate this uncertainty. To design more trustworthy visualizations for humanistic research, therefore, a deeper understanding of its relation to uncertainty is needed. We systematically reviewed 126 publications from digital humanities literature that use visualization as part of their research process, and examined how uncertainty was handled and represented in their visualizations. Crossing these dimensions with the visualization type and use, we identified that uncertainty originated from multiple steps in the research process from the source artifacts to their datafication. We also noted how besides known uncertainty coping strategies, such as excluding data and evaluating its effects, humanists also embraced uncertainty as a separate dimension important to retain. By mapping how the visualizations encoded uncertainty, we identified four approaches that varied in terms of explicitness and customization. This work contributes with two empirical taxonomies of uncertainty and it's corresponding coping strategies, as well as with the foundation of a research agenda for uncertainty visualization in the digital humanities. Our findings further the synergy among humanists and visualization researchers, and ultimately contribute to the development of more trustworthy, uncertainty-aware visualizations

    PERSPECTIVES ON THE PROSUMER ROLE IN THE SUSTAINABLE ENERGY SYSTEM

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    Climate change and the ever-growing demand for energy are pushing us to find new ways to manage energy production, distribution, and consumption. This energy transition is enabled, for example, by the digitalization, decentralization, and democratization of the energy system. The energy system is already transitioning from fossil-fuel and large power-plant–based generation toward a flexible system based on renewable energy sources. Traditional transmission grids are being replaced by smart grids enabled by digitalization that facilitate bi-directional flows of information and energy. At the consumption end, smart energy meters, energy monitoring devices and applications, and renewable energy technologies such as solar photovoltaic and battery storages empower energy consumers to evolve into prosumers: the producers and consumers of energy. These prosumers, also referred to as active consumers and energy citizens, are envisioned to play an important role in the sustainable energy system in the future. While the energy prosumer role has gained more research attention during the past few years, plenty of gaps in completely understanding energy prosumerism still remain. This research focuses on studying the prosumer role in the sustainable energy system. I study the enablers and activities of energy prosumers and explore how the growing number of prosumers may influence the socio-technical energy transition. The research presents two main perspectives on prosumerism; it explores both the micro and macro-level influences on the energy prosumers. The main research fields of this study are sustainability transitions, innovation studies, and policy. Based on theory and literature review, a novel research framework synthesizing the theoretical concepts and earlier research related to prosumers is introduced. From the methodology viewpoint, a pragmatic research approach and mixed methods are used to explore the enablers for prosumerism as well as prosumer activities and their impact on the ongoing energy transition. The research results are displayed in the form of six articles published in international peer-reviewed journals and conferences. The first two articles make propositions about the prosumer role as part of the changing socio-technical energy and innovation system. The next two articles focus on understanding the micro-level impact on the energy prosumers and examine the producer–consumer, in particular, as a co-developer of energy-related innovations. The remaining two articles address the impact of macro-level policies on prosumers. Overall, this research contributes to the understanding of the energy prosumer role in the future sustainable energy system. Theoretical contributions are related to the novel research framework that combines the concepts from the socio-technical multi-level perspective, innovation studies, and policy research as well as offers a more pragmatic framework for inquiry in the context of the changing energy system to observe the prosumer role therein. A specific theoretical contribution is made to the technology acceptance model that is tested in the context of external policy influence. Furthermore, the research contributes to innovation studies and especially to the field of user-centric innovations by bringing new results for understanding the factors behind end users’ collaboration interests. Practical contributions of the study are related to the understanding of the micro-foundations of prosumer interests toward innovation co-creation activities. Practitioners benefit from evidence concerning the differences between consumers and prosumers, which may help them in designing products and services for these different categories. This improved understanding is necessary, for example, to accelerate the diffusion of renewable energy technologies that is crucial for the sustainability transition. Policy- makers may benefit from the findings related to the policy analysis that combines and compares different prosumer activities with policy mixes and calls for a more holistic and systemic approach for the development of the prosumer related policies. While prosumer research has increased during the past decade, many future research avenues for the topic exist. For example, more research on prosumer role as part of the sustainability transition can help in designing better policies as well as products and services for consumers and prosumers. Moreover, systemic activities, such as those related to the integration of electric vehicle smart charging into the power system combined with other prosumer activities, offer opportunities for researchers. Furthermore, research concerning novel prosumer-centric business models, for instance related to energy communities, is needed to accelerate the diffusion of sustainable technology solutions. -- Ilmastomuutos ja kasvava energian kysyntä ajavat meidät etsimään uusia tapoja hallita energian tuotantoa, jakelua ja kulutusta. Energiajärjestelmä onkin jo siirtymässä fossiilisten polttoaineiden ja suurten voimalaitosten tuotannosta uusiutuviin energialähteisiin perustuvaan joustavaan järjestelmään. Sähköverkot on transformoitu digitalisoinnin mahdollistamana älykkäiksi Smart Grid -verkoiksi, jotka pystyvät siirtämään sekä energiaa että dataa molempiin suuntiin tuotannon ja kulutuksen välillä. Kulutuspäässä älykkäät energiamittarit, seurantalaitteet ja - sovellukset sekä uusiutuvien energialähteiden teknologiat, kuten aurinkosähkö ja akkuvarasto, antavat energiankuluttajille mahdollisuuden kehittyä prosumereiksi eli energian tuottaja-kuluttajiksi (engl. prosumer = producer-consumer). Prosumereilla, joihin viitataan myös nimillä ”aktiivinen kuluttaja” ja “energiakansalainen”, on tulevaisuudessa tärkeä rooli kestävässä energiajärjestelmässä. Vaikka prosumerit ovat saaneet lisää huomiota tutkimuksessa viime vuosina, energia prosumerismin ymmärtämisessä on vielä paljon aukkoja. Tämä tutkimus keskittyy selvittämään prosumerien roolia osana kestävää energiajärjestelmää ja sen murrosta. Tutkin prosumereihin liittyviä mahdollistajia, prosumerien toimintaa osana energiajärjestelmää sekä vaikutuksia kestävän kehityksen energiamurrokseen. Tutkimus on luonteeltaan monialainen, yhdistäen innovaatiotutkimusta, transitiotutkimusta ja myös jossain määrin politiikantutkimusta. Tässä pragmaattisessa tutkimuksessa käytetään sekä kvantitatiivisia että laadullisia tutkimusmetodeja. Tutkimuksen tulokset esitetään liitteenä olevien kuuden vertaisarvioidun konferenssi ja -journaaliartikkelin avulla. Ensimmäiset kaksi artikkelia esittävät propositioita prosumerin roolista osana muuttuvaa sosio-teknistä energia- ja innovaatiopelikenttää. Seuraavat kaksi artikkelia keskittyvät ymmärtämään mikrotason vaikutusta näihin toimijoihin ja tutkivat erityisesti energiaan liittyvien innovaatioiden yhteiskehittämistä. Lopuksi kaksi artikkelia käsittelevät makrotason politiikkatoimien vaikutusta prosumereihin. Tutkimuksen pääkontribuutio on ymmärryksen lisääminen kuluttajan muuttuvasta roolista osana energiajärjestelmää. Teoriakontribuutiot kytkeytyvät uusiin tapoihin yhdistää keskeisiä teorioita kestävän kehityksen transitiotutkimuksesta, innovaatiotutkimuksesta sekä politiikan tutkimuksesta. Käytännön elämään vaikuttavat kontribuutiot liittyvät empiirisiin tutkimustuloksiin esimerkiksi tavallisten kuluttajien ja prosumereiden eroista. Tietämyksen lisääminen auttaa teknologia- ja palveluyrityksiä suunnittelemaan tuotteita ja palveluita, jotka sopivat erilaisiin tarpeisiin, joka voi edelleen auttaa nopeuttamaan uusiutuvaan energiaan liittyvien innovaatioiden leviämistä ja siten edistää kestävää kehitystä. Prosumer -tutkimuksessa on edelleen paljon tilaa uudelle tieteenharjoitukselle. Esimerkiksi energiayhteisöt ovat yleistymässä ja tutkimus niiden roolista osana energiajärjestelmää on vasta käynnistynyt. Tutkimalla energiayhteisöjä pystytään lisäämään ymmärrystä niiden vaikutuksesta esimerkiksi sähköverkkoon ja lainsäädäntöön. Toisaalta myös yksittäisten aktiviteettien ja ajureiden tutkimuksessa on vielä paljon mahdollisuuksia. Esimerkiksi systeemiset ja integroidut ratkaisut, kuten sähköautojen käyttäminen osana kysyntäjoustoa, tarjoavat hyviä tutkimusaiheita. Lisäksi erityisesti uudet liiketoimintamallit liittyen prosumereihin ja energiayhteisöihin kaipaavat selkeyttämistä ja kokeiluja sekä regulaation muunnoksia

    A Comparative Study on Performance Evaluation of Intrusion Detection System through Feature Reduction for High Speed Networks

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    Abstract- The rapid growth in the usage of the internet had led to many serious security issues in the network The intrusion detection system IDS is one of the sophisticated defensive systems used to detect the malicious activities happening in the network services across the world Hence more advanced IDS are been developed in past few years To improve the performance of the IDS the system has to be trained effectively to increase the efficiency and decrease the false alarm rate To train the system the attributes selection plays the major role This paper evaluates and compares the performance of the intrusion detection systems for different feature reduction techniques in high speed network

    On Evaluating Commercial Cloud Services: A Systematic Review

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    Background: Cloud Computing is increasingly booming in industry with many competing providers and services. Accordingly, evaluation of commercial Cloud services is necessary. However, the existing evaluation studies are relatively chaotic. There exists tremendous confusion and gap between practices and theory about Cloud services evaluation. Aim: To facilitate relieving the aforementioned chaos, this work aims to synthesize the existing evaluation implementations to outline the state-of-the-practice and also identify research opportunities in Cloud services evaluation. Method: Based on a conceptual evaluation model comprising six steps, the Systematic Literature Review (SLR) method was employed to collect relevant evidence to investigate the Cloud services evaluation step by step. Results: This SLR identified 82 relevant evaluation studies. The overall data collected from these studies essentially represent the current practical landscape of implementing Cloud services evaluation, and in turn can be reused to facilitate future evaluation work. Conclusions: Evaluation of commercial Cloud services has become a world-wide research topic. Some of the findings of this SLR identify several research gaps in the area of Cloud services evaluation (e.g., the Elasticity and Security evaluation of commercial Cloud services could be a long-term challenge), while some other findings suggest the trend of applying commercial Cloud services (e.g., compared with PaaS, IaaS seems more suitable for customers and is particularly important in industry). This SLR study itself also confirms some previous experiences and reveals new Evidence-Based Software Engineering (EBSE) lessons
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