31 research outputs found

    Simulating resource management in fog computing systems

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    The fog computing paradigm was introduced to address the new challenges and requirements posed by the Internet of Things (IoT). It extends the cloud to the edge of the network, thereby facilitating processing and storing a massive amount of data where it is created and used. This novel computing paradigm is widely studied in both the academy and the industry, primarily by simulation. Today, a large variety of edge and fog computing simulators exist and are reviewed by several surveys. These reviews, however, mainly focus on high-level comparisons of these simulators and often make contradictory statements, which makes it difficult to assess what studies are feasible with a simulation tool. To address these challenges, we focus on a single state-of-the-art fog simulation tool, iFogSim2. In this paper, we provide an in-depth review of the simulator and examine its model, assumptions, and technical characteristics. Our analysis describes the details of fog resource management mechanisms implemented by iFogSim2 and discusses what it is capable of and where its limitations lie. We construct a case study to assess the tool's suitability for a mobile 5G scenario, namely, road surface weather analysis with smart vehicles. The case study is used to retrieve qualitative results of what is feasible with the tool, and what is not. We demonstrate that iFogSim2 has a valid locality model for the mobile 5G use case, but it is not suitable for experimenting with vehicular fog computing, dynamic placement, server-side service discovery, and load-balancing. In addition, we present a modeling and analytics framework, built for iFogSim2, to improve the simulation software and facilitate future research with the tool

    NFKB1 -94ins/delATTG polymorphism is a novel prognostic marker in first line-treated multiple myeloma

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    Nuclear factor kappa B (NFKB) plays an important role in multiple myeloma (MM), and bortezomib affects this pathway. We retrospectively analysed the effect of the NFKB1 -94ins/delATTG polymorphism on the survival of 295 MM patients treated at a single centre. The median progression-free survival (PFS) was 790 (659-921) d in patients with NFKB1 homozygous insertion genotype (I/I, n = 99) and 624 (515-733) d in deletion-carriers (I/D&D/D, n = 196, P = 0.013). In multivariate analysis, I/I carriers showed a favourable PFS compared to I/D&D/D with a hazard ratio of 0.622 (0.457-0.847), P = 0.003, in addition to international staging system (ISS) score, fluorescence in situ hybridization (FISH) risk score, age and bortezomib treatment. I/I patients benefited more from bortezomib treatment [PFS 902 (703-1101) and 580 (343-817), P = 0.008] than I/D&D/D patients [PFS 659 (487-831) and 488 (323-653), P = 0.531]; in addition the beneficial effect of low ISS score was not observed in the I/D&D/D group [PFS 639 (454-824) and 650 (458-842), P = 0.226], while it was clear in I/I patients [PFS 1140 (803-1477) and 580 (408-752), P < 0.001]. We conclude that homozygous carriers of the insertion allele of the NFKB1 -94ins/delATTG polymorphism have a better prognosis and probably benefit more from bortezomib treatment than MM patients carrying the deletion allele

    Why did socialist economies fail? The role of factor inputs reconsidered

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    We re-estimate investment and present revised growth accounts for three socialist economies between 1950 and 1989. Government statistics reported distorted measures for both the rate and trajectory of productivity growth in Czechoslovakia, Hungary, and Poland. Researchers have benefited from revised output data, but continued to use official statistics on capital input, or estimated capital stock from official investment data. Investment levels and rates of capital accumulations were much lower than officially claimed and over-reporting worsened over time. A setback in factor accumulation, both equipment investment and labor input, contributed very significantly to the socialist growth failure of the 1980s

    The seeds of divergence: the economy of French North America, 1688 to 1760

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    Generally, Canada has been ignored in the literature on the colonial origins of divergence with most of the attention going to the United States. Late nineteenth century estimates of income per capita show that Canada was relatively poorer than the United States and that within Canada, the French and Catholic population of Quebec was considerably poorer. Was this gap long standing? Some evidence has been advanced for earlier periods, but it is quite limited and not well-suited for comparison with other societies. This thesis aims to contribute both to Canadian economic history and to comparative work on inequality across nations during the early modern period. With the use of novel prices and wages from Quebec—which was then the largest settlement in Canada and under French rule—a price index, a series of real wages and a measurement of Gross Domestic Product (GDP) are constructed. They are used to shed light both on the course of economic development until the French were defeated by the British in 1760 and on standards of living in that colony relative to the mother country, France, as well as the American colonies. The work is divided into three components. The first component relates to the construction of a price index. The absence of such an index has been a thorn in the side of Canadian historians as it has limited the ability of historians to obtain real values of wages, output and living standards. This index shows that prices did not follow any trend and remained at a stable level. However, there were episodes of wide swings—mostly due to wars and the monetary experiment of playing card money. The creation of this index lays the foundation of the next component. The second component constructs a standardized real wage series in the form of welfare ratios (a consumption basket divided by nominal wage rate multiplied by length of work year) to compare Canada with France, England and Colonial America. Two measures are derived. The first relies on a “bare bones” definition of consumption with a large share of land-intensive goods. This measure indicates that Canada was poorer than England and Colonial America and not appreciably richer than France. However, this measure overestimates the relative position of Canada to the Old World because of the strong presence of land-intensive goods. A second measure is created using a “respectable” definition of consumption in which the basket includes a larger share of manufactured goods and capital-intensive goods. This second basket better reflects differences in living standards since the abundance of land in Canada (and Colonial America) made it easy to achieve bare subsistence, but the scarcity of capital and skilled labor made the consumption of luxuries and manufactured goods (clothing, lighting, imported goods) highly expensive. With this measure, the advantage of New France over France evaporates and turns slightly negative. In comparison with Britain and Colonial America, the gap widens appreciably. This element is the most important for future research. By showing a reversal because of a shift to a different type of basket, it shows that Old World and New World comparisons are very sensitive to how we measure the cost of living. Furthermore, there are no sustained improvements in living standards over the period regardless of the measure used. Gaps in living standards observed later in the nineteenth century existed as far back as the seventeenth century. In a wider American perspective that includes the Spanish colonies, Canada fares better. The third component computes a new series for Gross Domestic Product (GDP). This is to avoid problems associated with using real wages in the form of welfare ratios which assume a constant labor supply. This assumption is hard to defend in the case of Colonial Canada as there were many signs of increasing industriousness during the eighteenth and nineteenth centuries. The GDP series suggest no long-run trend in living standards (from 1688 to circa 1765). The long peace era of 1713 to 1740 was marked by modest economic growth which offset a steady decline that had started in 1688, but by 1760 (as a result of constant warfare) living standards had sunk below their 1688 levels. These developments are accompanied by observations that suggest that other indicators of living standard declined. The flat-lining of incomes is accompanied by substantial increases in the amount of time worked, rising mortality and rising infant mortality. In addition, comparisons of incomes with the American colonies confirm the results obtained with wages— Canada was considerably poorer. At the end, a long conclusion is provides an exploratory discussion of why Canada would have diverged early on. In structural terms, it is argued that the French colony was plagued by the problem of a small population which prohibited the existence of scale effects. In combination with the fact that it was dispersed throughout the territory, the small population of New France limited the scope for specialization and economies of scale. However, this problem was in part created, and in part aggravated, by institutional factors like seigneurial tenure. The colonial origins of French America’s divergence from the rest of North America are thus partly institutional

    The Seeds of Divergence: The Economy of French North America, 1688 to 1760

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    Transition, Integration and Convergence. The Case of Romania

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