2,243 research outputs found

    Risks, Safety and Security in the Ecosystem of Smart Cities

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    We have performed a review of systemic risks in smart cities dependent on intelligent and partly autonomous transport systems. Smart cities include concepts such as smart transportation/use of autonomous transportation systems (i.e., autonomous cars, subways, shipping, drones) and improved management of infrastructure (power and water supply). At the same time, this requires safe and resilient infrastructures and need for global collaboration. One challenge is some sort of risk based regulation of emergent vulnerabilities. In this paper we focus on emergent vulnerabilities and discussion of how mitigation can be organized and structured based on emergent and known scenarios cross boundaries. We regard a smart city as a software ecosystem (SEC), defined as a dynamic evolution of systems on top of a common technological platform offering a set of software solutions and services. Software ecosystems are increasingly being used to support critical tasks and operations. As a part of our work we have performed a systematic literature review of safety, security and resilience software ecosystems, in the period 2007–2016. The perspective of software ecosystems has helped to identify and specify patterns of safety, security and resilience on a relevant abstraction level. Significant vulnerabilities and poor awareness of safety, security and resilience has been identified. Key actors that should increase their attention are vendors, regulators, insurance companies and the research community. There is a need to improve private-public partnership and to improve the learning loops between computer emergency teams, security information providers (SIP), regulators and vendors. There is a need to focus more on safety, security and resilience and to establish regulations of responsibilities on the vendors for liabilities

    Relative generalized hamming weights and extended weight polynomials of almost affine codes

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    This is a post-peer-review, pre-copyedit version of an article published in Lecture Notes in Computer Science, International Castle Meeting on Coding Theory and Applications ICMCTA 2017: Coding Theory and Applications, 207-216. The final authenticated version is available online at: http://dx.doi.org/10.1007/978-3-319-66278-7_17 .This paper is devoted to giving a generalization from linear codes to the larger class of almost affine codes of two different results. One such result is how one can express the relative generalized Hamming weights of a pair of codes in terms of intersection properties between the smallest of these codes and subcodes of the largest code. The other result tells how one can find the extended weight polynomials, expressing the number of codewords of each possible weight, for each code in an infinite hierarchy of extensions of a code over a given alphabet. Our tools will be demi-matroids and matroids

    Swimming against the tide: supplier bridging roles in diffusing sustainability upstream and downstream in supply networks

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    Purpose: This paper aims to investigate the bridging role of first-tier suppliers in diffusing sustainability in supply networks and how this role is facilitated by the procurement function. Design/methodology/approach: The paper is based on an embedded case study of two supply networks of a coffee beans roasting company. The embedded cases focus on coffee beans and packaging supply networks. Findings: The findings reveal less than expected involvement of the focal company and its procurement function in sustainability implementation with first-tier suppliers. Instead, sustainability diffuses upstream to lower-tier suppliers but also downstream, against the tide, as a result of the various bridging roles performed by first-tier suppliers. Research limitations/implications: This paper provides two theoretical contributions. First, it contributes to the sustainable supply network management literature by providing rich insights on sustainability diffusion to lower-tier suppliers and the role of first-tier suppliers in this process. Second, the paper contributes to structural hole theory by revealing a typology of bridging roles that actors, such as suppliers, undertake in the sustainability context. Practical implications: The paper provides managers with practical insights on how sustainability can be diffused in the supply network and the different roles that first-tier suppliers can play in this direction. Originality/value: This paper shows that sustainability diffusion to lower-tier suppliers is possible in the absence of focal company procurement involvement when bridging roles are undertaken by first-tier suppliers and their procurement functions are involved in the implementation process. These bridging roles facilitate sustainability diffusion both upstream and downstream

    Vitamin K2 Facilitating Inter-Organ Cross-Talk

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    This chapter features how vitamin K2 is instrumental in bringing about inter-organ communication, thus facilitating (a) a synthesis/secretion of the endocrine, humoral factors from various organs and (b) physiological responses to the said factors by a multitude of organ systems of the body, thus creating a ‘lattice’ of reciprocal regulatory loops in order to ensure endocrine homeostasis

    Temperature dependence of binary and ternary recombination of H3+ ions with electron

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    We study binary and the recently discovered process of ternary He-assisted recombination of H3+ ions with electrons in a low temperature afterglow plasma. The experiments are carried out over a broad range of pressures and temperatures of an afterglow plasma in a helium buffer gas. Binary and He-assisted ternary recombination are observed and the corresponding recombination rate coefficients are extracted for temperatures from 77 K to 330 K. We describe the observed ternary recombination as a two-step mechanism: First, a rotationally-excited long-lived neutral molecule H3* is formed in electron-H3+ collisions. Second, the H3* molecule collides with a helium atom that leads to the formation of a very long-lived Rydberg state with high orbital momentum. We present calculations of the lifetimes of H3* and of the ternary recombination rate coefficients for para and ortho-H3+. The calculations show a large difference between the ternary recombination rate coefficients of ortho- and para-H3+ at temperatures below 300 K. The measured binary and ternary rate coefficients are in reasonable agreement with the calculated values.Comment: 15 page

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    Intet resum

    Recombination of H3+ Ions in the Afterglow of a He-Ar-H2 Plasma

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    Recombination of H3+ with electrons was studied in a low temperature plasma in helium. The plasma recombination rate is driven by two body, H3+ + e, and three-body, H3+ + e + He, processes with the rate coefficients 7.5x10^{-8}cm3/s and 2.8x10^{-25}cm6/s correspondingly at 260K. The two-body rate coefficient is in excellent agreement with results from storage ring experiments and theoretical calculations. We suggest that the three-body recombination involves formation of highly excited Rydberg neutral H3 followed by an l- or m- changing collision with He. Plasma electron spectroscopy indicates the presence of H3.Comment: 4 figure

    Mie light scattering calculations for an Indian age-related nuclear cataract with a high density of multilamellar bodies

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    Purpose: Multilamellar bodies (MLBs) are lipid-coated spheres (1–4 ”m in diameter) found with greater frequency in the nuclear region of human age-related cataracts compared with human transparent lenses. Mie light scattering calculations have demonstrated that MLBs are potential sources of forward light scattering in human age-related nuclear cataracts due to their shape, size, frequency, and cytoplasmic contents, which often differ in refractive index from their surroundings. Previous studies have used data from several non-serial tissue sections viewed by light microscopy to extrapolate a volume and have assumed that MLBs are random in distribution. Currently, confocal microscopy is being used to examine actual tissue volumes from age-related nuclear cataracts and transparent lenses collected in India to confirm MLB shape, size, frequency, and randomness. These data allow Mie scattering calculations to be done with directly observed MLBs in intact tissue. Methods: Whole Indian donor lenses and Indian lens nuclei after extracapsular cataract extraction were immersion-fixed in 10% formalin for 24 h and in 4% paraformaldehyde for 24 h before sectioning with a Vibratome. The 160 ”m thick sections were stained for 24 h in the lipid dye DiI (1,1’-dilinoleyl-3,3,3â€Č,3â€Č tetramethylindocarbocyanine, 4-chlorobenzenesulfonate), washed, stabilized in Permount under coverslips and examined with a Zeiss LSM 510 confocal microscope. Individual volumes of tissue (each typically 500,000 ”m3) were examined using a plan-apochromat 63X oil (NA=1.4) lens. Other lenses were prepared for electron microscopy and histological examination using previously described procedures. Results: Analysis of tissue volumes within Indian age-related nuclear cataracts and transparent lenses has confirmed that most MLBs are 1–4 ”m in diameter and typically spherical with some occurring as doublets or in clusters. Most Indian cataracts and transparent lenses are similar to samples obtained in the United States. One cataract contained as many as 400,000 MLBs per mm3 –100 times more than in cataracts collected in the United States. Pairwise distribution analysis has revealed that MLBs even in this exceptional case are found with a distribution that appears to be random. Mie calculations indicate that more than 90% of the incident light could be scattered by the high density of MLBs. Conclusions: An important finding was that one advanced Indian cataract contained many more MLBs than cataracts examined from India and previously from the United States. This indicates that specific conditions or susceptibilities may exist that promote the formation of excessive MLBs. Based on the extremely high frequency, as well as their spherical shape, large size, and apparent random distribution, the MLBs are predicted according to Mie light scattering calculations to cause high amounts of forward scattering sufficient to produce nuclear opacity
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