985 research outputs found

    The MVA Priority Approximation

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    A Mean Value Analysis (MVA) approximation is presented for computing the average performance measures of closed-, open-, and mixed-type multiclass queuing networks containing Preemptive Resume (PR) and nonpreemptive Head-Of-Line (HOL) priority service centers. The approximation has essentially the same storage and computational requirements as MVA, thus allowing computationally efficient solutions of large priority queuing networks. The accuracy of the MVA approximation is systematically investigated and presented. It is shown that the approximation can compute the average performance measures of priority networks to within an accuracy of 5 percent for a large range of network parameter values. Accuracy of the method is shown to be superior to that of Sevcik's shadow approximation

    Snapshot Processing in Streaming Environments

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    Computational issues related to streaming data, and in particular the monitoring and rapid correlation of multiple sources of streaming data, are becoming increasingly important in contexts ranging from business processes to crisis detection. For example, a government system to detect bioterror attacks must correlate multiple streams of possibly low-confidence data from sensors and local and national public health information networks with cues from indicators such as news and government sources indicating geographical locations, tactics and timing of possible attacks. The results of this correlation trigger appropriate responses, such as flagging information for more in-depth analysis or sending alerts to public health officials. Monitoring and correlation applications of this type are ideal for deployment on distributed computing grids, because they have high transaction throughput, require low latency, and can be partitioned into sets of small communicating computations with regular communication patterns. An important consideration in these applications is the need to ensure that, at any given time, computations are carried out on an accurate - or at least close to accurate - picture of the environment being monitored. One way of doing this, which we call snapshot processing, is to treat collections of events that occur at approximately the same time as representing a global snapshot - a valid state - of the environment. Computation on the resulting series of snapshots is much like computation on a real-time video of the entire environment. We briefly describe our model for these stream processing computations and introduce the concept of snapshot processin

    UC: a language for the connection machine

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    n designing parallel languages, the concern for defining a simple virtual machine must be balanced against the need to efficiently map a program on a specific architecture. UC addresses this problem by separating the programming task from efficiency considerations. UC programs are designed using a small set of constructs that include reduction, parallel assignment, and fixed-point computation. The language also provides a map section that may optionally be used by a programmer to specify data mappings for the program. The authors describe the UC constructs and their implementation on the Connection Machine. They also present measurements of the compiler for simple benchmarks

    HYALURONAN-A NOVEL POLYMER ISOLATED FROM MUTATED CLINICAL BACTERIAL ISOLATE

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    Objective: This study was done to optimize the production parameters involved in the isolation of hyaluronan (HA) from UV mutated a clinical strain of Klebsiella pneumonia (M 3020).Methods: Glucose and nitrogen enriched media (D-glucose, L-glutamic acid, and peptone) were utilized to cultivate the clinical isolate K. pneumoniae. The strain was Ultra Violet (UV) radiation mutated (254 nm, 25 min) and HA production was optimized by parameters such as pH and temperature. The isolated HA from the fermented broth was subjected to purification by isopropyl alcohol and silica gel and further dried by lyophilization. Produced HA was confirmed with UV and Fourier Transform Infra-Red (FT-IR) spectroscopy.Results: UV treated strain at 254 nm for 25 min predominantly produce a high quantity of HA (3.5 g/l) in 37 °C, 300 rpm and pH 6.8 at 24 h run. UV and IR spectrum of produced HA showed strong similarity with the standard hyaluronan.Conclusion: To conclude, high quantity and quality of HA can be isolated from mutated clinical strains of K. pneumoniae

    A parallel algorithm for correlating event streams

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    This paper describes a parallel algorithm for correlating or “fusing” streams of data from sensors and other sources of information. The algorithm is useful for applications where composite conditions over multiple data streams must be detected rapidly, such as intrusion detection or crisis management. The implementation of this algorithm on a multithreaded system and the performance of this implementation are also briefly described

    Enterprise Computing Systems as Information Factories

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    The analysis, and eventual approval or rejection, of new enterprise information technology (IT) initiatives often proceeds on the basis of informal estimates of return on investment. Investment in new IT initiatives includes the costs of hardware, software licenses, application development tailored to the enterprise, and maintenance. Returns are typically estimated informally in terms of cost savings or revenue increases. This paper makes the case for evaluating certain IT investments in the same way as investments in factories and other resources have been evaluated for decades. Just as industrial factories create value by transforming raw materials into finished products, some IT investments, which we call “information factories”, create value by transforming raw information (events) into structured data (and possibly actions based on that data). The return on investment is estimated by the difference between the economic value of the structured data and concomitant actions (the “finished product”) and that of the data available within the enterprise, from its partners and customers, and from the Internet (the “raw materials”). This paper introduces the concept of the information factory, and explores design considerations for maximizing the economic efficiency of information factories

    Effects of the Medicare Modernization Act on Spending for Outpatient Surgery

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/1/hesr12807_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/2/hesr12807-sup-0001-AppendixSA1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/3/hesr12807.pd

    Salmonella choleraesuis subsp. indica serovar bornheim causing urinary tract infection

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    An unusual Salmonella species, S. choleraesuis subsp. indica serovar bornheim, was isolated from the urine of a patient with aplastic anemia, diabetes mellitus, and a healed urethral injury. An immune response to this isolate was demonstrated by whole-bacterial-cell agglutination

    Salvage with a mini-allograft after primary engraftment failure following autologous transplant for multiple myeloma

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