341 research outputs found
P-LUPOSDATE: Using Precomputed Bloom Filters to Speed Up SPARQL Processing in the Cloud
Increasingly data on the Web is stored in the form of Semantic Web data. Because of today's information overload, it becomes very important to store and query these big datasets in a scalable way and hence in a distributed fashion. Cloud Computing offers such a distributed environment with dynamic reallocation of computing and storing resources based on needs. In this work we introduce a scalable distributed Semantic Web database in the Cloud. In order to reduce the number of (unnecessary) intermediate results early, we apply bloom filters. Instead of computing bloom filters, a time-consuming task during query processing as it has been done traditionally, we precompute the bloom filters as much as possible and store them in the indices besides the data. The experimental results with data sets up to 1 billion triples show that our approach speeds up query processing significantly and sometimes even reduces the processing time to less than half
New-onset diabetes and antihypertensive treatment
Introduction: Chronic diseases substantially contribute to the continuous increase in health care expenditures, including type-2 diabetes mellitus as one of the most expensive chronic diseases. Arterial hypertension presents a risk factor for the development of type-2 diabetes mellitus. Numerous analyses have demonstrated that antihypertensive therapies promote the development of type-2-diabetes mellitus. Studies indicate, that the application of angiotensin converting enzyme (ACE) inhibitors and angiotensin-receptor-blockers (ARB) lead to less new-onset diabetes compared to beta-blockers, diuretics and placebo. Given that beta-blockers and diuretics impair the glucose metabolism, the metabolic effects of different antihypertensive drugs should be regarded; otherwise not only the disease itself, but also antihypertensive therapies may promote the development of new-onset diabetes. Even though, the cost of ACE inhibitors and ARB are higher, the use in patients with metabolic disorders could be cost-effective in the long-term if new-onset diabetes is avoided. Objectives: To evaluate which class of antihypertensive agents promote the development or the manifestation of type-2 diabetes mellitus. How high is the incidence of new-onset diabetes during antihypertensive therapy and how is treatment-induced type-2 diabetes mellitus evaluated clinically? Which agents are therefore cost-effective in the long term? Which ethical, social or legal aspects should be regarded?MethodsA systematic literature review was conducted including clinical trials with at least ten participants which reported new-onset diabetes in the course of antihypertensive treatment. The trials had to be published after 1966 (after 2003 for economic publications) in English or German. Results: A total of 34 clinical publications meet the inclusion criteria. Of these, eight publications focus on the development of diabetes mellitus under treatment with diuretic and/or beta-blockers, six publications focused on ACE inhibitors alone or in combination with calcium-channel-blockers, ten publications on ARB and/or ACE inhibitors with respect to their effects on new-onset diabetes or their preventive aspects. Furthermore, five publications investigate the role of calcium-channel-antagonists in the development of diabetes, and five publications indicate the development of new-onset diabetes with different antihypertensive agents amongst each other or in comparison to no antihypertensive treatment. The clinical trials show a significant difference in the development of new-onset diabetes. Therapies with diuretics and/or beta-blockers result in a higher incidence of new-onset diabetes. ARB as well as ACE inhibitors have a preventive effect and calcium-channel-blockers show a neutral position regarding the development of new-onset diabetes. Two publications report on economic results. The first one evaluates the cost-effectiveness of ARB alone or in combination with calcium-channel-blockers in comparison to diuretics alone or in combination with beta-blockers. The second publication compares economic outcomes of calcium-channel-blockers and beta-blockers considering the development of new-onset diabetes. Treatment with the ARB candesartan lead to savings in total costs of 549 US-Dollar per patient and in incremental costs of 30,000 US-Dollar per diabetes mellitus avoided. In the second publication, costs to the amount of 18,965 Euro in Great Britain and 13,210 Euro in Sweden are quoted for an avoided event. The treatment with calcium-channel-blockers compared to beta-blockers is proven to be more cost-effective. No publications were identified regarding ethical, social and legal aspects. Discussion: The available meta-analyses allow for a high clinical evidence level. A few studies vary in terms of diabetes definition and study duration. In most of the trials, the incidence of new-onset diabetes is not an endpoint. The evaluation of treatment-induced diabetes mellitus cannot be conducted, due to the lack of sufficient results in the identified literature. The two economic studies do not address all the objectives sufficiently. Ethical, social and legal aspects are discussed but not analysed systematically. Conclusion: Based on these studies, sufficient evidence to confirm the presumption that diuretics and/or beta-blockers promote the development of new-onset diabetes compared to other antihypertensive agents, especially in patients who are predisposed, is presented with this report. Trials reflecting the clinical relevance of treatment-induced diabetes mellitus compared to existing diabetes mellitus regarding cardiovascular outcomes are required. Also health economic evaluations considering the development of new-onset diabetes should be conducted for the different classes of antihypertensive agents
Nonlinear output feedback and periodic disturbance attenuation for a speed tracking of a combustion engine test bench
The quality of control actions depends strongly on the availability and the quality of signals to construct the controller. While most control design tools assume all states, hence signals, are measurable, this is often unrealistic. An observer is often necessary to use in controller implementation. This paper proposes a reduced order observer design and output feedback control for a class of nonlinear systems, namely extended Hammerstein systems. We apply the proposed design to a combustion engine testbench, to solve a set point tracking problem. As in real practice the measured signals are often affected by periodic disturbance from combustion oscillations, the controller is extended with an internal model based filter, to remove the effect of the disturbance. Some simulation results are presented, comparing the performance of the proposed output feedback with the state feedback controller
Road Friction Virtual Sensing:A Review of Estimation Techniques with Emphasis on Low Excitation Approaches
In this paper, a review on road friction virtual sensing approaches is provided. In particular, this work attempts to address whether the road grip potential can be estimated accurately under regular driving conditions in which the vehicle responses remain within low longitudinal and lateral excitation levels. This review covers in detail the most relevant effect-based estimation methods; these are methods in which the road friction characteristics are inferred from the tyre responses: tyre slip, tyre vibration, and tyre noise. Slip-based approaches (longitudinal dynamics, lateral dynamics, and tyre self-alignment moment) are covered in the first part of the review, while low frequency and high frequency vibration-based works are presented in the following sections. Finally, a brief summary containing the main advantages and drawbacks derived from each estimation method and the future envisaged research lines are presented in the last sections of the paper
Prognostic Value of Self-Reported Versus Objectively Measured Functional Capacity in Patients With Heart Failure Results From the TIME-CHF (Trial of Intensified Versus Standard Medical Therapy in Elderly Patients With Congestive Heart Failure)
- …