1,093 research outputs found

    Analysis of Transaction Management Performance

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    There is currently much interest in incorporating transactions into both operating systems and general purpose programming languages. This paper provides a detailed examination of the design and performance of the“¢ transaction manager of the Camelot system. Camelot is a transaction facility that provides a rich model of transactions intended to support a wide variety of general-purpose applications. The transaction manager's principal function is to execute the protocols that ensure atomicity. The conclusions of this study are: a simple optimization to two-phase commit reduces logging activity of distributed transactions; non-blocking commit is practical for some applications; multithreaded design improves throughput provided that log batching is used; multi-casting reduces the variance of distributed commit protocols in a LAN environment; and the performance of transaction mechanisms such as Camelot depend heavily upon kernel performance

    216 Jewish Hospital of St. Louis

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    https://digitalcommons.wustl.edu/bjc_216/1168/thumbnail.jp

    216 Jewish Hospital of St. Louis

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    https://digitalcommons.wustl.edu/bjc_216/1171/thumbnail.jp

    Rise and demise of the global silver standard

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    In the early modern period, the world economy gravitated around the expansion of long-distance commerce. Together with navigation improvements, silver was the prime commodity which moved the sails of such trade. The disparate availability and the particular demand for silver across the globe determined the participation of producers, consumers, and intermediaries in a growing global economy. American endowments of silver are a known feature of this process; however, the fact that the supply of silver was in the form of specie is a less known aspect of the integration of the global economy. This chapter surveys the production and export of silver specie out of Spanish America, its intermediation by Europeans, and the reexport to Asia. It describes how the sheer volume produced and the quality and consistency of the coin provided familiarity with, and reliability to, the Spanish American peso which made it current in most world markets. By the eighteenth century, it has become a currency standard for the international economy which grew together with the production and coinage of silver. Implications varied according to the institutional settings to deal with specie and foreign exchange in each intervening economy of that trade. Generalized warfare in late eighteenth-century Europe brought down governance in Spanish America and coinage fragmented along with the political fragmentation of the empire. The emergence of new sovereign republics and the end of minting as known meant the cessation of the silver standard that had contributed to the early modern globalization

    Maintaining consistency in distributed systems

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    In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability

    The Terlingua Quicksilver Deposits, Brewster County

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    "Quicksilver-Occurence, production, prices, etc., by Wm. B. Phillips": p. 53-74.Bulletin of the University of Texas, no. 15Mode of access: Internet

    Seeking out and building monopolies, Rothschild strategies in non ferrous metals international markets (1830-1940)

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    The aim of this article is to analyse the strategies employed by the Rothschilds until 1940 to limit competition in the non ferrous international market. We will study how they opted for rigid demand products of highly concentrated supply which were favourable to market control (mercury, nickel, lead and copper and sulphur) by assuming administrative monopolies (mercury from Spanish Almadn Mines) or through control of the leading businesses of the respective markets (Le Nickel, Pearroya and Rio Tinto). We will also analyse how the family was able to gain worldwide monopolies, or if not, how they promoted collusive oligopolies with the competition in any number of forms in their quest to maintain profitability and to flee from any competition.International Raw material markets, Cartels, Rothschild, mining, Non-ferrous metals.

    ‘It Wasn't the Money Boat’: The Myth and Reality of Treasure Hunting for Western River Steamboats in the United States

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    This dissertation chronicles the historical record of the attempt to recover treasure from buried western river steamboats in the United States by examining the site formation of steamboat wreck sites, treasure myths, protective legislation regarding historic shipwrecks, and treasure hunting attempts from the late-nineteenth century to modern day. Primary accounts from the nineteenth century through current day, including newspapers, magazines, literature, narratives written by treasure hunters, legislative agendas, legal documents, and court case proceedings, were utilized. Seven case studies of steamboats targeted by treasure hunters were included: Missouri Packet (1820), Ben Sherrod (1837), Arabia (1856), Twilight (1865), Bertrand (1865), Leodora (1866), and City of New Orleans (unidentified). Each of these vessels sunk in the nineteenth century and later became the target of treasure seekers who hoped to recover valuables. In the nineteenth century, the steamboat was a crucial mode of transportation of goods and people. Cargoes included foodstuffs, raw materials, ceramics, clothing, alcoholic spirits, and tools. Basically, if it was needed or wanted, it could be found in the cargo hold of a steamboat. Despite their utility, transporting goods by steamboat involved risk. Accidents—including boiler explosions or being impaled by snags—were common. In many cases, the boat sank after an accident. Some steamboats and their cargo were salvaged shortly after they sank. Others were abandoned, either inaccessible or forgotten. An abandoned vessel potentially holds thousands of artifacts, some of it with potential market value. Thus, western river steamboats have become the subject of treasure hunting lore. These tales focused on rumored whiskey cargoes and precious metals buried on steamboats along the Ohio, Mississippi, and Missouri rivers and their tributaries. Treasure hunters of late nineteenth century attempted to get at the rumored treasure but often failed due to difficult conditions. Later attempts proved to be more thorough, and they could also prove to be more destructive to the archaeological record. Treasure hunters have recovered thousands of artifacts but no treasure troves. Some have worked to conserve and display artifacts. At the same time, treasure hunting methods are often at odds with archaeological principles and the conservation of cultural heritage

    216 Jewish Hospital of St. Louis

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    https://digitalcommons.wustl.edu/bjc_216/1162/thumbnail.jp

    Sequence stratigraphic interpretation methods for low-accommodation, alluvial depositional sequences: applications to reservoir characterization of Cut Bank field, Montana

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    In South Central Cut Bank Sand Unit (SCCBSU) of Cut Bank field, primary production and waterflood projects have resulted in recovery of only 29 % of the original oil in place from heterogeneous, fluvial sandstone deposits. Using highresolution sequence stratigraphy and geostatistical analysis, I developed a geologic model that may improve the ultimate recovery of oil from this field. In this study, I assessed sequence stratigraphic concepts for continental settings and extended the techniques to analyze low-accommodation alluvial systems of the Cut Bank and Sunburst members of the lower Kootenai formation (Cretaceous) in Cut Bank field. Identification and delineation of five sequences and their bounding surfaces led to a better understanding of the reservoir distribution and variability. Recognition of stacking patterns allowed for the prediction of reservoir rock quality. Within each systems tract, the best quality reservoir rocks are strongly concentrated in the lowstand systems tract. Erosional events associated with falling baselevel resulted in stacked, communicated (multistory) reservoirs. The lowermost Cut Bank sandstone has the highest reservoir quality and is a braided stream parasequence. Average net-to-gross ratio value (0.6) is greater than in other reservoir intervals. Little additional stratigraphically untapped oil is expected in the lowermost Cut Bank sandstone. Over most of the SCCBSU, the Sunburst and the upper Cut Bank strata are valley-fill complexes with interfluves that may laterally compartmentalize reservoir sands. Basal Sunburst sand (Sunburst 1, average net-to-gross ratio ~0.3) has better reservoir quality than other Sunburst or upper Cut Bank sands, but its reservoir quality is significantly less than that of lower Cut Bank sand. Geostatistical analysis provided equiprobable representations of the heterogeneity of reservoirs. Simulated reservoir geometries resulted in an improved description of reservoir distribution and connectivity, as well as occurrences of flow barriers. The models resulting from this study can be used to improve reservoir management and well placement and to predict reservoir performance in Cut Bank field. The technical approaches and tools from this study can be used to improve descriptions of other oil and gas reservoirs in similar depositional systems
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