5,654 research outputs found

    A Trust Management Framework for Vehicular Ad Hoc Networks

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    The inception of Vehicular Ad Hoc Networks (VANETs) provides an opportunity for road users and public infrastructure to share information that improves the operation of roads and the driver experience. However, such systems can be vulnerable to malicious external entities and legitimate users. Trust management is used to address attacks from legitimate users in accordance with a user’s trust score. Trust models evaluate messages to assign rewards or punishments. This can be used to influence a driver’s future behaviour or, in extremis, block the driver. With receiver-side schemes, various methods are used to evaluate trust including, reputation computation, neighbour recommendations, and storing historical information. However, they incur overhead and add a delay when deciding whether to accept or reject messages. In this thesis, we propose a novel Tamper-Proof Device (TPD) based trust framework for managing trust of multiple drivers at the sender side vehicle that updates trust, stores, and protects information from malicious tampering. The TPD also regulates, rewards, and punishes each specific driver, as required. Furthermore, the trust score determines the classes of message that a driver can access. Dissemination of feedback is only required when there is an attack (conflicting information). A Road-Side Unit (RSU) rules on a dispute, using either the sum of products of trust and feedback or official vehicle data if available. These “untrue attacks” are resolved by an RSU using collaboration, and then providing a fixed amount of reward and punishment, as appropriate. Repeated attacks are addressed by incremental punishments and potentially driver access-blocking when conditions are met. The lack of sophistication in this fixed RSU assessment scheme is then addressed by a novel fuzzy logic-based RSU approach. This determines a fairer level of reward and punishment based on the severity of incident, driver past behaviour, and RSU confidence. The fuzzy RSU controller assesses judgements in such a way as to encourage drivers to improve their behaviour. Although any driver can lie in any situation, we believe that trustworthy drivers are more likely to remain so, and vice versa. We capture this behaviour in a Markov chain model for the sender and reporter driver behaviours where a driver’s truthfulness is influenced by their trust score and trust state. For each trust state, the driver’s likelihood of lying or honesty is set by a probability distribution which is different for each state. This framework is analysed in Veins using various classes of vehicles under different traffic conditions. Results confirm that the framework operates effectively in the presence of untrue and inconsistent attacks. The correct functioning is confirmed with the system appropriately classifying incidents when clarifier vehicles send truthful feedback. The framework is also evaluated against a centralized reputation scheme and the results demonstrate that it outperforms the reputation approach in terms of reduced communication overhead and shorter response time. Next, we perform a set of experiments to evaluate the performance of the fuzzy assessment in Veins. The fuzzy and fixed RSU assessment schemes are compared, and the results show that the fuzzy scheme provides better overall driver behaviour. The Markov chain driver behaviour model is also examined when changing the initial trust score of all drivers

    Mathematical Problems in Rock Mechanics and Rock Engineering

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    With increasing requirements for energy, resources and space, rock engineering projects are being constructed more often and are operated in large-scale environments with complex geology. Meanwhile, rock failures and rock instabilities occur more frequently, and severely threaten the safety and stability of rock engineering projects. It is well-recognized that rock has multi-scale structures and involves multi-scale fracture processes. Meanwhile, rocks are commonly subjected simultaneously to complex static stress and strong dynamic disturbance, providing a hotbed for the occurrence of rock failures. In addition, there are many multi-physics coupling processes in a rock mass. It is still difficult to understand these rock mechanics and characterize rock behavior during complex stress conditions, multi-physics processes, and multi-scale changes. Therefore, our understanding of rock mechanics and the prevention and control of failure and instability in rock engineering needs to be furthered. The primary aim of this Special Issue “Mathematical Problems in Rock Mechanics and Rock Engineering” is to bring together original research discussing innovative efforts regarding in situ observations, laboratory experiments and theoretical, numerical, and big-data-based methods to overcome the mathematical problems related to rock mechanics and rock engineering. It includes 12 manuscripts that illustrate the valuable efforts for addressing mathematical problems in rock mechanics and rock engineering

    Soundscape in Urban Forests

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    This Special Issue of Forests explores the role of soundscapes in urban forested areas. It is comprised of 11 papers involving soundscape studies conducted in urban forests from Asia and Africa. This collection contains six research fields: (1) the ecological patterns and processes of forest soundscapes; (2) the boundary effects and perceptual topology; (3) natural soundscapes and human health; (4) the experience of multi-sensory interactions; (5) environmental behavior and cognitive disposition; and (6) soundscape resource management in forests

    Innovation in Energy Security and Long-Term Energy Efficiency Ⅱ

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    The sustainable development of our planet depends on the use of energy. The increasing world population inevitably causes an increase in the demand for energy, which, on the one hand, threatens us with the potential to encounter a shortage of energy supply, and, on the other hand, causes the deterioration of the environment. Therefore, our task is to reduce this demand through different innovative solutions (i.e., both technological and social). Social marketing and economic policies can also play their role by affecting the behavior of households and companies and by causing behavioral change oriented to energy stewardship, with an overall switch to renewable energy resources. This reprint provides a platform for the exchange of a wide range of ideas, which, ultimately, would facilitate driving societies toward long-term energy efficiency

    Essays on Manufacturers’ IT Capabilities for Digital Servitization

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    Over the last decades, studies have found that transformational drivers affect how firms innovate their business models (Chesbrough, 2010; Massa et al., 2016). In markets in which physical products become commodities, the servitization of business models is a transformational driver for firms (Wise & Baumgartner, 1999). For its part, digitalization increases the potential to reshape business models through novel use cases of technology (Yoo et al., 2010). Recently, digitalization was found to extend the opportunities from servitization through digital technologies as digital servitization (Paschou et al., 2020). Digital servitization describes a firm’s shift from product-centric offerings to service-centric offerings with the help of novel IT assets (Naik et al., 2020). The manufacturing industry provides promising examples of firms with portfolios of physical offerings that might undergo such a transformational shift (Baines et al., 2017). So far, digital servitization research focuses primarily on four topics: re-defining the notion of servitization in the context of digitalization, identifying digital servitization value drivers, linking the transformation to specific technologies, and deriving how novel service offerings arise (Paschou et al., 2020; Zhou & Song, 2021). Despite the breadth of digital servitization research, how firms can shift to service-centric offerings remains unclear (Kohtamäki et al., 2019). Specifically, research lacks studies on the prerequisites and mechanisms that link theory with evidence on achieving IT-enabled service innovation (Paschou et al., 2020). Further, how firms must organize to build and operate IT-enabled services around these technologies remains unclear (Paschou et al., 2020). In a recent report on the manufacturing industry, practitioners confirm these gaps and associate them with a lack of managerial and technical knowledge (Illner et al., 2020). A theoretical lens that helps to address these shortcomings is the knowledge-based theory. It suggests that knowledge is the primary rationale, so that a firm benefits from its assets (Grant, 1996b; Nonaka, 1994). The knowledge-based theory understands a capability as a directed application of knowledge in a firm’s activities (Grant, 1996b; Nonaka, 1994). In the context of digitalization, firms require IT capabilities based on knowledge of how to capitalize on IT assets (Lee et al., 2015). Digital servitization research finds that IT capabilities are critical for identifying, adapting, and exploiting IT-enabled service innovations (Johansson et al., 2019). Still, little extant research informs firms that undergo digital servitization about which IT capabilities can help to strengthen their competitive advantage (Coreynen et al., 2017). Even though IT capabilities may be necessary for success in innovating IT-enabled services, the required knowledge needs to be disseminated effectively throughout an organization (Foss et al., 2014; Grant, 1996a; Nonaka, 1994). The organizational control theory offers a theoretical perspective about knowledge dissemination mechanisms, which can be horizontal or vertical (Ouchi, 1979). Horizontal knowledge dissemination mechanisms depend on codifying processes in rules or measuring process outputs through indicators, while the locus of exerting these rules and indicators determines the vertical knowledge dissemination. The IT innovation and IT governance literature refers to these knowledge dissemination mechanisms as formalization of IT activities and centralization of IT decision-making (Weill, 2004; Winkler & Brown, 2013; Zmud, 1982). However, how to orchestrate knowledge, particularly for IT capabilities, in firms that undergo digital servitization is not yet clear (Kohtamäki et al., 2019; Münch et al., 2022; Sjödin et al., 2020). Against this background, this dissertation addresses how manufacturers organize their IT capabilities while encountering the transformational drivers of digital servitization by answering the following overarching research question: How can manufacturers organize their IT capabilities to capitalize on digital servitization? (References to be found in the full text):List of abbreviations in synopsis............................................................................................................V Part I: Synopsis of the dissertation..........................................................................................................11 Motivation.......................................................................................................................................12 Research design...............................................................................................................................22. 1Conceptual approach and research objectives....................................................................22. 2Research methodologies and methods................................................................................4 3Structure of the dissertation.............................................................................................................5 3.1Systematization of the papers.............................................................................................5 3.2Paper1: Revisiting the concept of IT capabilities in the era of digitalization....................7 3.3Paper2: Short and sweet –Multiple mini case studies as a form of rigorous case studyresearch...............................................................................................................................9 3.4Paper3: Linking IT capabilities and competitive advantage of servitized business models..........................................................................................................................................11 3.5Paper4: From selling machinery to hybrid offerings –Organizational impact of digitalservitization on manufacturing firms................................................................................11 3.6Paper5: Manufacturers’ IT-enabled service innovation success as a multifacetedphenomenon: A configurational study..............................................................................13 3.7Paper6: The missing piece –Calibration of qualitative data for qualitative comparativeanalyses in IS research......................................................................................................14 3.8Paper7: Prerequisites and causal recipes for manufacturers’ success in innovating ITenabled services................................................................................................................16 4Conclusion.....................................................................................................................................19 4.1Resultssummary...............................................................................................................19 4.2Contributions....................................................................................................................20 4.2.1Theoretical contributions......................................................................................20 4.2.2Methodological contribution................................................................................21 4.2.3Practical contribution............................................................................................21 4.3Limitations and future research........................................................................................22 5References.....................................................................................................................................24 Part II: Papers of the dissertation...........................................................................................................29 Paper1: Revisiting the concept of IT capabilities in the era of digitalization.......................................30 Paper2: Short and sweet –Multiple mini case studies as a form of rigorous case study research.......41 Paper3: Linking IT capabilities and competitive advantage of servitized business model..................64 Paper4: From selling machinery to hybrid offerings –Organizational impact of digital servitization on manufacturing firms......................................................................................................................80 Paper5: Manufacturers’ IT-enabled service innovation success as a multifaceted phenomenon: A configurational study...................................................................................................................108 Paper6: The missing piece –Calibration of qualitative data for qualitative comparative analyses in IS research........................................................................................................................................119 Paper7: Prerequisites and causal recipes for manufacturers’ success in innovating IT-enabled services.....................................................................................................................................................136 Overview of the digital appendix on CD.............................................................................................17

    Systemic Circular Economy Solutions for Fiber Reinforced Composites

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    This open access book provides an overview of the work undertaken within the FiberEUse project, which developed solutions enhancing the profitability of composite recycling and reuse in value-added products, with a cross-sectorial approach. Glass and carbon fiber reinforced polymers, or composites, are increasingly used as structural materials in many manufacturing sectors like transport, constructions and energy due to their better lightweight and corrosion resistance compared to metals. However, composite recycling is still a challenge since no significant added value in the recycling and reprocessing of composites is demonstrated. FiberEUse developed innovative solutions and business models towards sustainable Circular Economy solutions for post-use composite-made products. Three strategies are presented, namely mechanical recycling of short fibers, thermal recycling of long fibers and modular car parts design for sustainable disassembly and remanufacturing. The validation of the FiberEUse approach within eight industrial demonstrators shows the potentials towards new Circular Economy value-chains for composite materials

    Reshaping Higher Education for a Post-COVID-19 World: Lessons Learned and Moving Forward

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    Accurate Battery Modelling for Control Design and Economic Analysis of Lithium-ion Battery Energy Storage Systems in Smart Grid

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    Adoption of lithium-ion battery energy storage systems (Li-ion BESSs) as a flexible energy source (FES) has been rapid, particularly for active network management (ANM) schemes to facilitate better utilisation of inverter based renewable energy sources (RES) in power systems. However, Li-ion BESSs display highly nonlinear performance characteristics, which are based on parameters such as state of charge (SOC), temperature, depth of discharge (DOD), charge/discharge rate (C-rate), and battery-aging conditions. Therefore, it is important to include the dynamic nature of battery characteristics in the process of the design and development of battery system controllers for grid applications and for techno-economic studies analyzing the BESS economic profitability. This thesis focuses on improving the design and development of Li-ion BESS controllers for ANM applications by utilizing accurate battery performance models based on the second-order equivalent-circuit dynamic battery modelling technique, which considers the SOC, C-rate, temperature, and aging as its performance affecting parameters. The proposed ANM scheme has been designed to control and manage the power system parameters within the limits defined by grid codes by managing the transients introduced due to the intermittence of RESs and increasing the RES penetration at the same time. The validation of the ANM scheme and the effectiveness of controllers that manage the flexibilities in the power system, which are a part of the energy management system (EMS) of ANM, has been validated with the help of simulation studies based on an existing real-life smart grid pilot in Finland, Sundom Smart Grid (SSG). The studies were performed with offline (short-term transient-stability analysis) and real-time (long-term transient analysis) simulations. In long-term simulation studies, the effect of battery aging has also been considered as part of the Li-ion BESS controller design; thus, its impact on the overall power system operation can be analyzed. For this purpose, aging models that can determine the evolving peak power characteristics associated with aging have been established. Such aging models are included in the control loop of the Li-ion BESS controller design, which can help analyse battery aging impacts on the power system control and stability. These analyses have been validated using various use cases. Finally, the impact of battery aging on economic profitability has been studied by including battery-aging models in techno-economic studies.Aurinkosähköjärjestelmien ja tuulivoiman laajamittainen integrointi sähkövoimajärjestelmän eri jännitetasoille on lisääntynyt nopeasti. Uusiutuva energia on kuitenkin luonteeltaan vaihtelevaa, joka voi aiheuttaa nopeita muutoksia taajuudessa ja jännitteessä. Näiden vaihteluiden hallintaan tarvitaan erilaisia joustavia energiaresursseja, kuten energiavarastoja, sekä niiden tehokkaan hyödyntämisen mahdollistaviea älykkäitä ja aktiivisia hallinta- ja ohjausjärjestelmiä. Litiumioniakkuihin pohjautuvien invertteriliitäntäisten energian varastointijärjestelmien käyttö joustoresursseina aktiiviseen verkonhallintaan niiden pätö- ja loistehon ohjauksen avulla on lisääntynyt nopeasti johtuen niiden kustannusten laskusta, modulaarisuudesta ja teknisistä ominaisuuksista. Litiumioniakuilla on erittäin epälineaariset ominaisuudet joita kuvaavat parametrit ovat esimerkiksi lataustila, lämpötila, purkaussyvyys, lataus/ purkausnopeus ja akun ikääntyminen. Akkujen ominaisuuksien dynaaminen luonne onkin tärkeää huomioida myös akkujen sähköverkkoratkaisuihin liittyvien säätöjärjestelmien kehittämisessä sekä teknis-taloudellisissa kannattavuusanalyyseissa. Tämä väitöstutkimus keskittyy ensisijaisesti aktiiviseen verkonhallintaan käytettävien litiumioniakkujen säätöratkaisuiden parantamiseen hyödyntämällä tarkkoja, dynaamisia akun suorituskykymalleja, jotka perustuvat toisen asteen ekvivalenttipiirien akkumallinnustekniikkaan, jossa otetaan huomioon lataustila, lataus/purkausnopeus ja lämpötila. Työssä kehitetyn aktiivisen verkonhallintajärjestelmän avulla tehtävät akun pätö- ja loistehon ohjausperiaatteet on validoitu laajamittaisten simulointien avulla, esimerkiksi paikallista älyverkkopilottia Sundom Smart Gridiä simuloimalla. Simuloinnit tehtiin sekä lyhyen aikavälin offline-simulaatio-ohjelmistoilla että pitkän aikavälin simulaatioilla hyödyntäen reaaliaikasimulointilaitteistoa. Pitkän aikavälin simulaatioissa akun ikääntymisen vaikutus otettiin huomioon litiumioniakun ohjauksen suunnittelussa jotta sen vaikutusta sähköjärjestelmän kokonaistoimintaan voitiin analysoida. Tätä tarkoitusta varten luotiin akun ikääntymismalleja, joilla on mahdollista määrittää akun huipputehon muutos sen ikääntyessä. Akun huipputehon muutos taas vaikuttaa sen hyödynnettävyyteen erilaisten pätötehon ohjaukseen perustuvien joustopalveluiden tarjoamiseen liittyen. Lisäksi väitöstutkimuksessa tarkasteltiin akkujen ikääntymisen vaikutusta niiden taloudelliseen kannattavuuteen sisällyttämällä akkujen ikääntymismalleja teknis-taloudellisiin tarkasteluihin.fi=vertaisarvioitu|en=peerReviewed

    Tradition and Innovation in Construction Project Management

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    This book is a reprint of the Special Issue 'Tradition and Innovation in Construction Project Management' that was published in the journal Buildings

    Current issues of the management of socio-economic systems in terms of globalization challenges

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    The authors of the scientific monograph have come to the conclusion that the management of socio-economic systems in the terms of global challenges requires the use of mechanisms to ensure security, optimise the use of resource potential, increase competitiveness, and provide state support to economic entities. Basic research focuses on assessment of economic entities in the terms of global challenges, analysis of the financial system, migration flows, logistics and product exports, territorial development. The research results have been implemented in the different decision-making models in the context of global challenges, strategic planning, financial and food security, education management, information technology and innovation. The results of the study can be used in the developing of directions, programmes and strategies for sustainable development of economic entities and regions, increasing the competitiveness of products and services, decision-making at the level of ministries and agencies that regulate the processes of managing socio-economic systems. The results can also be used by students and young scientists in the educational process and conducting scientific research on the management of socio-economic systems in the terms of global challenges
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