Metrics and Algorithms for Processing Multiple Continuous Queries

Data streams processing is an emerging research area that is driven by the growing need for monitoring applications. A monitoring application continuously processes streams of data for interesting, significant, or anomalous events. Such applications include tracking the stock market, real-time detection of diseaseoutbreaks, and environmental monitoring via sensor networks.Efficient employment of those monitoring applications requires advanced data processing techniques that can support the continuous processing of unbounded rapid data streams. Such techniques go beyond the capabilities of the traditional store-then-query Data BaseManagement Systems. This need has led to a new data processing paradigm and created a new generation of data processing systems,supporting continuous queries (CQ) on data streams.Primary emphasis in the development of first generation Data Stream Management Systems (DSMSs) was given to basic functionality. However, in order to support large-scale heterogeneous applications that are envisioned for subsequent generations of DSMSs, greater attention willhave to be paid to performance issues. Towards this, this thesis introduces new algorithms and metrics to the current design of DSMSs.This thesis identifies a collection of quality ofservice (QoS) and quality of data (QoD) metrics that are suitable for a wide range of monitoring applications. The establishment of well-defined metrics aids in the development of novel algorithms that are optimal with respect to a particular metric. Our proposed algorithms exploit the valuable chances for optimization that arise in the presence of multiple applications. Additionally, they aim to balance the trade-off between the DSMS's overall performance and the performance perceived by individual applications. Furthermore, we provide efficient implementations of the proposed algorithms and we also extend them to exploit sharing in optimized multi-query plans and multi-stream CQs. Finally, we experimentally show that our algorithms consistently outperform the current state of the art

Homotopy Continuation Method for Solving a Class of Slightly Perturbed Equations

In the present paper, an iterative method of second order convergence for solving a class of slightly perturbed equations is established using homotopy continuation technique. The accuracy of the method is very high and verified through two applications, in the first application we fix all the input parameters of our algorithm and allow the homotopy function to vary. For this application we considered as a typical example, Kepler equation of elliptical motion. In the second applications, the function is fixed while the other input parameters of the algorithm are varied, and we used for these applications seven highly transcendental slightly perturbed equations. The most important characteristic of the method is that it does not need any priori knowledge of the initial guess, a property which avoids the critical situations between divergent to very slow convergent solutions, that may exist in the application of other numerical methods which depending on initial guess. Moreover, the method allows freedom in choosing the function in order to secure any required accuracy

The Comparative Evaluation of the Post-Antimicrobial Effect of MTAD® and 2% Chlorhexidine against Enterococcus faecalis of Permanent Teeth with Necrotic Pulp

AIM: Enterococcus faecalis is one of the most resistant bacteria in necrotic teeth. That’s why the goal of this study was to determine the post-antibiotic effect of MTAD®& 2% Chlorhexidine® as root canal irrigating solution on clinical isolates of E. faecalis from infected root canals of permanent teeth, using the spectrophotometric technique. MATERIAL AND METHODS: The antibacterial efficacy of Chloramphenicol 30 mcg, Nitrofurantoin 300 mcg, Vancomycin 5 mcg, Amoxicillin/clavulanic acid 30 mcg and Ofloxacin 5 mcg against E. faecalis was compared using the Disc diffusion method. Patients were selected for this study with permanent necrotic teeth. The sterile paper point was inserted inside the infected root canal and left for 60 seconds; to obtain the microbiological sample. Postantibiotic effect of MTAD® and 2% Chlorohexidine® on E. faecalis was compared. The absorbance of bacterial growth was examined for both irrigating solutions during the first 10 hours with an hour interval, and then tested at 48, 72, 96 up to 240 hours. RESULTS: The results showed that during the first 10 hours, MTAD® showed immediate antibacterial effect and maintained its higher antibacterial activity than 2% chlorohexidine®. After 48, 72, 96 and 240 hours, both MTAD® and 2% chlorohexidine® showed the same prolonged action of post-antibiotic effect against E. faecalis with a non-significant difference. According to Antibiotic sensitivity, the results revealed MTAD® is the most effective antimicrobial drug, showing the highest zone of inhibition, followed by 2% Chlorhexidine and Nitrofurantoin 300 mcg which showed the same inhibitory activity CONCLUSION: From the current study, it can be concluded that MTAD® has a strong bactericidal effect against E. faecalis and showed the highest zone of inhibition

Recent advances in numerical simulation and control of asymmetric flows around slender bodies

The problems of asymmetric flow around slender bodies and its control are formulated using the unsteady, compressible, thin-layer or full Navier-Stokes equations which are solved using an implicit, flux-difference splitting, finite-volume scheme. The problem is numerically simulated for both locally-conical and three-dimensional flows. The numerical applications include studies of the effects of relative incidence, Mach number and Reynolds number on the flow asymmetry. For the control of flow asymmetry, the numerical simulation cover passive and active control methods. For the passive control, the effectiveness of vertical fins placed in the leeward plane of geometric symmetry and side strakes with different orientations is studied. For the active control, the effectiveness of normal and tangential flow injection and surface heating and a combination of these methods is studied

Nosocomial imipenem-resistant Acinetobacter baumannii infections in intensive care units: incidence and risk factors assessment

Imipenem-resistant Acinetobacter baumannii (A. baumannii) (IRAB) has emerged as a challenging nosocomial pathogen particularly in intensive care units (ICUs). Studying the risk factors associated with IRAB infection is of paramount importance for appropriate control of IRAB spread. The aim of this study was to assess the incidence rate and possible risk factors associated with nosocomial IRAB infections in ICUs. A prospective cohort study was carried out in surgical and emergency ICUs of a tertiary care hospital in Egypt. All patients who developed nosocomial A. baumannii infection from the start of January 2014 to the end of December 2015 were included. Isolates were identified as A. baumannii using API 20NE and E-test was used to define IRAB. Out of 146 A. baumannii isolates, 11 were found to be IRAB (7.5% incidence rate), of them 72.7% (8/11) were found to be multidrug resistant (MDR). Univariate analysis demonstrated that hospital stay before ICU admission [Relative risk (RR) 3.51, 95% confidence interval (CI) 1.0- 12.7, P= 0.04)], longer ICU stay (P= 0.005), exposure to emergent surgery (RR 17.5, CI 7.39-41.4, P= 0.000), the presence of central venous catheter (RR 3.26, CI 1.0-10.6, P= 0.04) and previous carbapenem use (RR 4.05, CI 1.12-14.6, P =0.02) were significant risk factors for IRAB infection. In conclusion, a relatively high IRAB incidence was recorded in ICUs of our hospital. Hospital stay before ICU admission, longer ICU stay, exposure to emergent surgery, the presence of central venous catheter and previous carbapenem use were significant risk factors for IRAB infection. Rationale use of carbapenems in ICUs should be considered.Keywords: Imipenem-resistant, Acinetobacter baumannii, Intensive care unit