8,866 research outputs found
Optimal Elephant Flow Detection
Monitoring the traffic volumes of elephant flows, including the total byte
count per flow, is a fundamental capability for online network measurements. We
present an asymptotically optimal algorithm for solving this problem in terms
of both space and time complexity. This improves on previous approaches, which
can only count the number of packets in constant time. We evaluate our work on
real packet traces, demonstrating an up to X2.5 speedup compared to the best
alternative.Comment: Accepted to IEEE INFOCOM 201
Clustering Patients with Tensor Decomposition
In this paper we present a method for the unsupervised clustering of
high-dimensional binary data, with a special focus on electronic healthcare
records. We present a robust and efficient heuristic to face this problem using
tensor decomposition. We present the reasons why this approach is preferable
for tasks such as clustering patient records, to more commonly used
distance-based methods. We run the algorithm on two datasets of healthcare
records, obtaining clinically meaningful results.Comment: Presented at 2017 Machine Learning for Healthcare Conference (MLHC
2017). Boston, M
Charter-School Management Organizations: Diverse Strategies and Diverse Student Impacts
Examines the growth of charter school management organizations, characteristics of students served, and use of resources; CMO practices; impact on students, including middle school test scores; and structures and practices linked to positive outcomes
Efficient Measurement on Programmable Switches Using Probabilistic Recirculation
Programmable network switches promise flexibility and high throughput,
enabling applications such as load balancing and traffic engineering. Network
measurement is a fundamental building block for such applications, including
tasks such as the identification of heavy hitters (largest flows) or the
detection of traffic changes.
However, high-throughput packet processing architectures place certain
limitations on the programming model, such as restricted branching, limited
capability for memory access, and a limited number of processing stages. These
limitations restrict the types of measurement algorithms that can run on
programmable switches. In this paper, we focus on the RMT programmable
high-throughput switch architecture, and carefully examine its constraints on
designing measurement algorithms. We demonstrate our findings while solving the
heavy hitter problem.
We introduce PRECISION, an algorithm that uses \emph{Probabilistic
Recirculation} to find top flows on a programmable switch. By recirculating a
small fraction of packets, PRECISION simplifies the access to stateful memory
to conform with RMT limitations and achieves higher accuracy than previous
heavy hitter detection algorithms that avoid recirculation. We also analyze the
effect of each architectural constraint on the measurement accuracy and provide
insights for measurement algorithm designers.Comment: To appear in IEEE ICNP 201
A systematic review of the role of bisphosphonates in metastatic disease
Objectives: To identify evidence for the role of bisphosphonates in malignancy for the treatment of hypercalcaemia, prevention of skeletal morbidity and use in the adjuvant setting. To perform an economic review of current literature and model the cost effectiveness of bisphosphonates in the treatment of hypercalcaemia and prevention of skeletal morbidity Data sources: Electronic databases (1966-June 2001). Cochrane register. Pharmaceutical companies. Experts in the field. Handsearching of abstracts and leading oncology journals (1999-2001). Review methods: Two independent reviewers assessed studies for inclusion, according to predetermined criteria, and extracted relevant data. Overall event rates were pooled in a meta-analysis, odds ratios ( OR) were given with 95% confidence intervals (CI). Where data could not be combined, studies were reported individually and proportions compared using chi- squared analysis. Cost and cost-effectiveness were assessed by a decision analytic model comparing different bisphosphonate regimens for the treatment of hypercalcaemia; Markov models were employed to evaluate the use of bisphosphonates to prevent skeletal-related events (SRE) in patients with breast cancer and multiple myeloma. Results: For acute hypercalcaemia of malignancy, bisphosphonates normalised serum calcium in >70% of patients within 2-6 days. Pamidronate was more effective than control, etidronate, mithramycin and low-dose clodronate, but equal to high dose clodronate, in achieving normocalcaemia. Pamidronate prolongs ( doubles) the median time to relapse compared with clodronate or etidronate. For prevention of skeletal morbidity, bisphosphonates compared with placebo, significantly reduced the OR for fractures (OR [95% CI], vertebral, 0.69 [0.57-0.84], non-vertebral, 0.65 [0.54-0.79], combined, 0.65 [0.55-0.78]) radiotherapy 0.67 [0.57-0.79] and hypercalcaemia 0.54 [0.36-0.81] but not orthopaedic surgery 0.70 [0.46-1.05] or spinal cord compression 0.71 [0.47-1.08]. However, reduction in orthopaedic surgery was significant in studies that lasted over a year 0.59 [0.39-0.88]. Bisphosphonates significantly increased the time to first SRE but did not affect survival. Subanalyses were performed for disease groups, drugs and route of administration. Most evidence supports the use of intravenous aminobisphosphonates. For adjuvant use of bisphosphonates, Clodronate, given to patients with primary operable breast cancer and no metastatic disease, significantly reduced the number of patients developing bone metastases. This benefit was not maintained once regular administration had been discontinued. Two trials reported significant survival advantages in the treated groups. Bisphosphonates reduce the number of bone metastases in patients with both early and advanced breast cancer. Bisphosphonates are well tolerated with a low incidence of side-effects. Economic modelling showed that for acute hypercalcaemia, drugs with the longest cumulative duration of normocalcaemia were most cost-effective. Zoledronate 4 mg was the most costly, but most cost-effective treatment. For skeletal morbidity, Markov models estimated that the overall cost of bisphosphonate therapy to prevent an SRE was pound250 and pound1500 per event for patients with breast cancer and multiple myeloma, respectively. Bisphosphonate treatment is sometimes cost-saving in breast cancer patients where fractures are prevented. Conclusions: High dose aminobisphosphonates are most effective for the treatment of acute hypercalcaemia and delay time to relapse. Bisphosphonates significantly reduce SREs and delay the time to first SRE in patients with bony metastatic disease but do not affect survival. Benefit is demonstrated after administration for at least 6-12 months. The greatest body of evidence supports the use of intravenous aminobisphosphonates. Further evidence is required to support use in the adjuvant setting
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