168 research outputs found

    Demystifying EQA statistics and reports

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    Reports act as an important feedback tool in External Quality Assessment (EQA). Their main role is to score laboratories for their performance in an EQA round. The most common scores that apply to quantitative data are Q- and Z-scores. To calculate these scores, EQA providers need to have an assigned value and standard deviation for the sample. Both assigned values and standard deviations can be derived chemically or statistically. When derived statistically, different anomalies against the normal distribution of the data have to be handled. Various procedures for evaluating laboratories are able to handle these anomalies. Formal tests and graphical representation techniques are discussed and suggestions are given to help choosing between the different evaluations techniques. In order to obtain reliable estimates for calculating performance scores, a satisfactory number of data is needed. There is no general agreement about the minimal number that is needed. A solution for very small numbers is proposed by changing the limits of evaluation. Apart from analyte- and sample-specific laboratory evaluation, supplementary information can be obtained by combining results for different analytes and samples. Various techniques are overviewed. It is shown that combining results leads to supplementary information, not only for quantitative, but also for qualitative and semi-quantitative analytes

    Design and control technique for single phase bipolar H-bridge inverter connected to the grid

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    The power quality injected into the grid and the performance of the converter system depend on the quality of the inverter current control. This paper proposes a design and control technique for a photovoltaic inverter connected to the grid based on the digital pulse-width modulation (DSPWM) which can synchronise a sinusoidal output current with a grid voltage and control a power factor. The current injected must be sinusoidal with reduced harmonic distortion. The connected PV system is based on H-Bridge inverter controlled by bipolar PWM Switching. The current control technique and functional structure of this system are presented and simulated. Detailed analysis, Simulations results of output voltage and current waveform demonstrate the contribution of this approach to determinate the suitable control of the system. A digital design of a generator PWM using VHDL is proposed and implemented on an Xilinx FPGA and it has been validated with experimental results. As a result, the proposed inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications

    Pharmaceutical pricing policies in Qatar and Lebanon: narrative review and document analysis

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    Objectives: This study aimed at reviewing and analysing the pharmaceutical pricing policies implemented in two middle-east countries. Methods: Official documents related to national pharmaceutical pricing policies were reviewed, and meetings with key informants in the registration and pricing departments in the Qatari and Lebanese ministries of public health were conducted. Key findings: As of April 2017, the laws currently in effect in Qatar and Lebanon are based on the latest versions of decrees enacted in 2011 and 2005 respectively. Both countries have implemented similar pharmaceutical pricing policies which apply only to the private sectors in both countries. Landing price in Lebanon is either free-on-board (FOB) or cost-insurance-freight (CIF) while it is only CIF in Qatar. External reference pricing and mark-up regulations were two of the common policies identified in both countries. For external reference pricing, the basket of countries considered and the price adopted were different. Mark-ups were applied with different schemes along the pharmaceutical supply chain in each country with Qatar imposing an overall higher mark-up margin. Moreover, Qatar utilized health technology assessment whenever such economic evaluation studies were available at the time of medicine registration. These pricing strategies applied to both public and private sectors in Lebanon, while they only applied to the private sector in Qatar. Conclusions: The pharmaceutical pricing policies implemented in Qatar and Lebanon are reflective of both the advancements in the human capital and financial resources of the nations and are in line with the World Health Organization-recommended pricing policies for developing countries.This work was supported by Qatar University [QUST-CPH-SPR-15/16-7 and QUST-CPH-SPR\2017-18].Scopu

    3-Hy­droxy-4-phenyl-1-(prop-2-en-1-yl)-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-2-one

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    The asymmetric unit of the title compound, C18H18N2O2, contains three independent mol­ecules. In each, the seven-membered diazepine ring adopts a boat conformation with the hy­droxy-substituted C atom at the prow and fused-ring C atoms at the stern. In the crystal, the mol­ecules are linked by O—H⋯O and N—H⋯O hydrogen bonds. The allyl group of one mol­ecule is equally disordered over two positions

    Relationship between pharmaceutical pricing strategies with price, availability, and affordability of cardiovascular disease medicines: Surveys in Qatar and Lebanon

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    Background: Cardiovascular diseases are the leading cause of death in Lebanon and Qatar. When lifestyle modifications prove insufficient, medication becomes a cornerstone in controlling such diseases and saving lives. Price, availability, and affordability hinder the equitable access to medicines. The study aimed to assess prices, availability, and affordability of essential cardiovascular disease medicines in relation to pricing strategies in Qatar and Lebanon. Methods: A cross-sectional survey using a variant of the World Health Organization and Health Action International (WHO/HAI) methodology as outlined in "Measuring medicine prices, availability, affordability and price components" (2008), second edition, was adopted. Prices and availability of 27 cardiovascular medicines were collected from public and private dispensing outlets. For international comparison, prices were adjusted to purchasing power parity. Data was analyzed across multiple sectors, within and across countries. Results: A total of 15 public and private outlets were surveyed in each country. Prices were more uniform in Qatar than in Lebanon. In the public sector, medicines were free-of-charge in Lebanon and priced lower than the international reference prices in Qatar. The ratio of medicine unit price to international reference price in the private sectors surveyed are significantly higher than the acceptable threshold of 4. This ratio of originator brands and lowest priced generics in Qatar were up to two and five times those in Lebanon, respectively, even after adjusting for purchasing power parity. However, prices of lowest priced generics in the private sector were at least 35% cheaper in Qatar and 65% cheaper in Lebanon than their comparative originator brands. Medicines were more available in the private sector in Lebanon than in Qatar, but only the originator brand availability in the public sector in Qatar exceeded the WHO target of more than 80%. While affordable in the public sector in Qatar, four out of thirteen medicines exceeded the threshold in all private sectors covered. Hence, only the public sector in Qatar had a satisfying level of availability and affordability. Conclusions: Except for the Qatari public sector, medicine prices, availability, and affordability are falling short from targets. Key policy decisions should be implemented to improve access to medicines. - 2019 The Author(s).This study was supported by Qatar University with the grants’ numbers (QUST-CPH-SPR-15/16–7 & QUST-CPH-SPR\2017–18). It funded the collection of data and a revision of the written English. The publication fee for this article was funded by the Qatar National Library.Scopu

    5-Acetyl-3-hy­droxy-4-phenyl-4,5-dihydro-1H-1,5-benzodiazepin-2(3H)-one

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    In the title compound, C17H16N2O3, the seven-membered diazepine ring adopts a boat conformation with the hy­droxy-substituted C atom at the prow and fused benzene ring C atoms at the stern. The phenyl substituent occupies an equatorial position. The amino group of the ring system is a hydrogen-bond donor to the oxo O atom of an inversion-related mol­ecule, and the hy­droxy group is a hydrogen-bond donor to the acetyl O atom of another inversion-related mol­ecule. The two hydrogen bonds generate a ribbon motif parallel to [10] in the crystal structure

    RETRACTED : Elastic-plastic analysis of reinforced composite materials

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    This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see : http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 25 June 202

    Intelligent and Improved Self-Adaptive Anomaly based Intrusion Detection System for Networks

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    With the advent of digital technology, computer networks have developed rapidly at an unprecedented pace contributing tremendously to social and economic development. They have become the backbone for all critical sectors and all the top Multi-National companies. Unfortunately, security threats for computer networks have increased dramatically over the last decade being much brazen and bolder. Intrusions or attacks on computers and networks are activities or attempts to jeopardize main system security objectives, which called as confidentiality, integrity and availability. They lead mostly in great financial losses, massive sensitive data leaks, thereby decreasing efficiency and the quality of productivity of an organization. There is a great need for an effective Network Intrusion Detection System (NIDS), which are security tools designed to interpret the intrusion attempts in incoming network traffic, thereby achieving a solid line of protection against inside and outside intruders. In this work, we propose to optimize a very popular soft computing tool prevalently used for intrusion detection namely Back Propagation Neural Network (BPNN) using a novel machine learning framework called “ISAGASAA”, based on Improved Self-Adaptive Genetic Algorithm (ISAGA) and Simulated Annealing Algorithm (SAA). ISAGA is our variant of standard Genetic Algorithm (GA), which is developed based on GA improved through an Adaptive Mutation Algorithm (AMA) and optimization strategies. The optimization strategies carried out are Parallel Processing (PP) and Fitness Value Hashing (FVH) that reduce execution time, convergence time and save processing power. While, SAA was incorporated to ISAGA in order to optimize its heuristic search. Experimental results based on Kyoto University benchmark dataset version 2015 demonstrate that our optimized NIDS based BPNN called “ANID BPNN-ISAGASAA” outperforms several state-of-art approaches in terms of detection rate and false positive rate. Moreover, improvement of GA through FVH and PP saves processing power and execution time. Thus, our model is very much convenient for network anomaly detection.
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