4,605 research outputs found

    Non Parametric Distributed Inference in Sensor Networks Using Box Particles Messages

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    This paper deals with the problem of inference in distributed systems where the probability model is stored in a distributed fashion. Graphical models provide powerful tools for modeling this kind of problems. Inspired by the box particle filter which combines interval analysis with particle filtering to solve temporal inference problems, this paper introduces a belief propagation-like message-passing algorithm that uses bounded error methods to solve the inference problem defined on an arbitrary graphical model. We show the theoretic derivation of the novel algorithm and we test its performance on the problem of calibration in wireless sensor networks. That is the positioning of a number of randomly deployed sensors, according to some reference defined by a set of anchor nodes for which the positions are known a priori. The new algorithm, while achieving a better or similar performance, offers impressive reduction of the information circulating in the network and the needed computation times

    Strengthening the Security of the Kuwait International Airport by Detecting Threats in X-ray Images

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    The substantial number of false positives in X-ray analysis of images is one of the current problems, which causes delays and adds to the responsibilities of security staff. Maintaining security measures to confront growing threats and new technology is a continuing concern. Using a Convolutional Neural Network-Gated Recurrent Unit (CNN-GRU) model, this research suggests a novel strategy for upgrading the safety precautions at Kuwait International Airport. This research tackles the requirement for more precise and efficient threat detection, which is crucial for airport security. Utilizing the advantages of CNNs and GRUs is the goal of the CNN-GRU approach. The GRU, a recurrent neural network, can evaluate the ordered sequence of X-ray scans and keep context across time. At the same time, the CNN element is skilled at extracting features and can interpret X-ray images to identify potential hazards. With the help of this communication, the model is better equipped to identify hidden risks and is more accurate. This research involves a thorough analysis of the effectiveness of the suggested model via intensive training and testing. The findings show that the CNN-GRU model works better than traditional approaches in recognizing threats in X-ray pictures, considerably lowering false positives and increasing safety precautions at Kuwait International Airport. The CNN-GRU model’s deployment reflects an innovative approach to security at airports, offering a reliable and flexible instrument to protect passengers and staff successfully. This study contributes to continuing attempts to maintain and improve airport security in a threat environment that is always changing

    Cost analysis study of price variation among the various brands of proton pump inhibitors available in Benghazi-Libya

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    Background: A large proportion of patients in developing countries have to pay out of pocket for their medications. The prices of different brands of the same medications vary considerably and may vary from one community pharmacy to another. This study was undertaken to evaluate the variation in costs of proton pump inhibitors (PPI) and histamine H2-receptor antagonists available in Libya. Methods: Prices of various brands of PPI and various formulations were collected from four community pharmacies in the city of Benghazi. Both cost ratio and percentage variation were calculated and compared for various brands of the same strength and number of tablets, capsules, injections, or syrups. Results: The highest cost ratio and percentage price variation were found with omeprazole 20 mg, followed by omeprazole 40 mg. Other significant cost variations (>100%) were seen with pantoprazole 40 mg, Downoprazol (omeprazole + sodium bicarbonate) 40 mg, and esomeprazole 40 mg. Ampoules of omeprazole, cimetidine, and ranitidine had cost ratios of 1:1.7, 1:1.7, and 1:1.8, and cost variation ratios of 71.4, 66.7, and 75, respectively. Variations in prices of PPI and histamine H2 antagonists from the same manufacturer between different community pharmacies were common. The highest percentage cost variation (100) was seen with omeprazole 20 mg. Conclusions: Due to political instability, the prices of all drugs are controlled by importing private companies and the owners of community pharmacies instead of governmental authorities, that leads to cost variations. Therefore, the health authorities exert strict control on pricing of medications

    Chemokine and Chemokine Receptor Gene Polymorphism in Tunisian Hemodialysis Patients with HCV Infection

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    Introduction: Our aim was to investigate the possibility of a significant relationship between chemokines and chemokine receptor genes polymorphisms and the spontaneous clearance or the persistence of HCV infection. Methods: A total of 96 hemodialysis (HD) patients infected with HCV were classified into two groups: G1 included 73 patients with persistently positive HCV-RNA and G2 included 23 HD patients who have spontaneously eliminated the virus. The control group consisted of 170 healthy blood donors. All subjects were genotyped for CCR5 Δ32, CCR5 (-59029) A/G, CCR2 (64Ile) and MCP-1(-2518) A/G gene polymorphisms. Results: Our results showed statistically significant increased frequencies of the CCR2 (64Ile) and the (-59029) CCR5 A alleles in patients infected with HCV (22.1% and 35.9%) compared to G1 (24.3% and 40.6%) and compared to controls (14.4% and 20%). We also observed a lower frequency of the MCP-1 G allele and a greater frequency of the CCR5Δ32 variant in G2 (15.2% and 6.5%) compared to G1 (22.6% and 1.4%) that was not statistically significant. However, adjustment for known covariates (age, gender and HCV genotypes) didn’t confirm the results of univariate analysis. Conclusion: In conclusion, our study suggests a possible role for some of the studied chemokines polymorphisms in the spontaneous clearance or persistence of HCV infection in Tunisian population. These results should be further investigated by a prospective cohort studies and large population-based studies.Keywords: Chemokines; Receptors; Hepatitis C virus; Spontaneous Clearance; Polymorphisms

    An Expression for Nonlinear Noise in Optical Phase Conjugation Systems with Lumped Amplifiers

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    We develop an analytical formula for evaluating the impact of fiber nonlinearity in systems employing optical phase conjugation with multi-span lumped amplification, highlighting the detailed balance of effects leading to compensation when the phase conjugator is added to the middle of the link. We apply the approach to the effect of adding a pre-dispersion element to improve the symmetry, deriving the required optimum predispersion. The closed-form is validated through simulation and shows good matching with the results within a margin of error less than 0.2 dB

    Near-threshold boson pair production in the model of smeared-mass unstable particles

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    Near-threshold production of boson pairs is considered within the framework of the model of unstable particles with smeared mass. We describe the principal aspects of the model and consider the strategy of calculations including the radiative corrections. The results of calculations are in good agreement with LEP II data and Monte-Carlo simulations. Suggested approach significantly simplifies calculations with respect to the standard perturbative one.Comment: 15 pages, 6 figures, minor corrections, references adde

    Ultrasonographic findings in patients with abdominal symptoms or trauma presenting to an emergency room in rural Tanzania

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    BACKGROUND: Frequencies of ultrasonographic findings and diagnoses in emergency departments in sub-Saharan Africa are unknown. This study aimed to describe the frequencies of different sonographic findings and diagnoses found in patients with abdominal symptoms or trauma presenting to a rural referral hospital in Tanzania. METHODS: In this prospective observational study, we consecutively enrolled patients with abdominal symptoms or trauma triaged to the emergency room of the Saint Francis Referral Hospital, Ifakara. Patients with abdominal symptoms received an abdominal ultrasound. Patients with an abdominal or thoracic trauma received an Extended Focused Assessment with Ultrasound in Trauma (eFAST). RESULTS: From July 1st 2020 to June 30th 2021, a total of 88838 patients attended the emergency department, of which 7590 patients were triaged as 'very urgent' and were seen at the emergency room. A total of 1130 patients with abdominal symptoms received an ultrasound. The most frequent findings were abnormalities of the uterus or adnexa in 409/754 females (54.2%) and abdominal free fluid in 368 (32.6%) patients; no abnormality was found in 150 (13.5%) patients. A tumour in the abdomen or pelvis was found in 183 (16.2%) patients, an intrauterine pregnancy in 129/754 (17.1%) females, complete or incomplete abortion in 96 (12.7%), and a ruptured ectopic pregnancy in 32 (4.2%) females. In males, most common diagnosis was intestinal obstruction in 54/376 (14.4%), and splenomegaly in 42 (11.2%). Of 1556 trauma patients, 283 (18.1%) received an eFAST, and 53 (18.7%) had positive findings. A total of 27 (9.4%) trauma patients and 51 (4.5%) non-trauma patients were sent directly to the operating theatre. CONCLUSION: In this study, ultrasound examination revealed abnormal findings for the majority of patients with non-traumatic abdominal symptoms. Building up capacity to provide diagnostic ultrasound is a promising strategy to improve emergency services, especially in a setting where diagnostic modalities are limited

    Higher Order Power Corrections in Inclusive B Decays

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    We discuss order 1/m_b^4 and 1/m_b^5 corrections in inclusive semileptonic decay of a BB meson. We identify relevant hadronic matrix elements of dimension seven and eight and estimate them using the ground-state saturation approximation. Within this approach the effects on the integrated rate and on kinematic moments are estimated. The overall relative shift in V_{cb} turns out about +0.4% as applied to the existing fits. Similar estimates are presented for B -> X_s+\gamma decays.Comment: 30 pages, 16 figure
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