137 research outputs found

    A new model for threat assessment in data fusion based on fuzzy evidence theory

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    In this paper a new method for threat assessment is proposed based on Fuzzy Evidence Theory. The most widely classical and intelligent methods used for threat assessment systems will be Evidence or Dempster Shafer and Fuzzy Sets Theories. The disadvantage of both methods is failing to calculate of uncertainty in the data from the sensors and the poor reliability of system. To fix this flaw in the system of dynamic targets threat assessment is proposed fuzzy evidence theory as a combination of both Dempster- Shafer and Fuzzy Sets Theories. In this model, the uncertainty in input data from the sensors and the whole system is measured using the best measure of the uncertainty. Also, a comprehensive comparison is done between the uncertainty of fuzzy model and fuzzy- evidence model (proposed method). This method applied to a real time scenario for air threat assessment. The simulation results show that this method is reasonable, effective, accuracy and reliability

    Target threat assessment using fuzzy sets theory

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    The threat evaluation is significant component in target classification process and is significant in military and non military applications. Small errors or mistakes in threat evaluation and target classification especial in military applications can result in huge damage of life and property. Threat evaluation helps in case of weapon assignment, and intelligence sensor support system. It is very important factor to analyze the behavior of enemy tactics as well as our surveillance. This paper represented a precise description of the threat evaluation process using fuzzy sets theory. A review has been carried out regarding which parameters that have been suggested for threat value calculation. For the first time in this paper, eleven parameters are introduced for threat evaluation so that this parameters increase the accuracy in designed system. The implemented threat evaluation system has been applied to a synthetic air defense scenario and four real time dynamic air defense scenarios. The simulation results show the correctness, accuracy, reliability and minimum errors in designing of threat evaluation syste

    The improvement of uncertainty measurements accuracy in sensor networks based on fuzzy dempster-shafer theory

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    Threat Assessment is one of the most important components in combat management systems. However, uncertainty is one of the problems that occur in the input data of these systems that have been provided using several sensors in sensor networks. In literature, there are some theories that state and model uncertainty in the information. One of the new methods is the Fuzzy Dempster-Shafer Theory. In this paper, a model-based uncertainty is presented in the air defense system based on the Fuzzy Dempster-Shafer Theory to measure uncertainty and its accuracy. This model uses the two concepts naming of the Fuzzy Sets Theory, and the Dempster-Shafer Theory. The input parameters to sensors are fuzzy membership functions, and the basic probability assignment values are earned from the Dempster-Shafer Theory. Therefore, in this paper, the combination of two methods has been used to calculate uncertainty in the air defense system. By using these methods and the output of the Dempster-Shafer theory are calculated and presented the uncertainty diagrams. The advantage of the combination of two theories is the better modeling of uncertainties. This makes that the output of the air defense system is more reliable and accurate. In this method, the air defense system’s total uncertainty is measured using the best uncertainty measure based on the Fuzzy Dempster-Shafer Theory. The simulation results show that this new method has increased the accuracy to 97% that is more computational toward other theories. This matter significantly increases the computational accuracy of the air defense system in targets threat assessment

    Timing calibration for up-converting DAC

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    This thesis deals with the timing error problem that appears in high frequency Digital to Analog Converters. Inequalities among signal paths in different branches and inaccuracies happened during fabrication, result in different time delays in different branches of a Digital to Analog Converter. The consequence of this inequality is having the data for different bits not arriving to the summation point at the same time. This timing error will create some glitches in the output analog signal. A new approach is introduced in this work that measures the timing error among branches of the DAC and corrects them through a calibration process. Being all the error measurement and its correction process done on chip, this approach can correct the errors created by both sources. This idea was implemented and tested in Eldo simulator. A timing error of 8pS was inserted to the MSB branch of a 10-bit binary coded DAC. After performing the calibration process on this DAC, the SFDR of the output signal was increased by about 3.2dB

    A Real-time Global Optimal Path Planning for mobile robot in Dynamic Environment Based on Artificial Immune Approach

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    This paper illustrates a method to finding a globaloptimal path in a dynamic environment of known obstacles foran Mobile Robot (MR) to following a moving target. Firstly, theenvironment is defined by using a practical and standard graphtheory. Then, a suboptimal path is obtained by using DijkstraAlgorithm (DA) that is a standard graph searching method. Theadvantages of using DA are; elimination the uncertainness ofheuristic algorithms and increasing the speed, precision andperformance of them. Finally, Continuous Clonal SelectionAlgorithm (CCSA) that is combined with Negative SelectionAlgorithm (NSA) is used to improve the suboptimal path andderive global optimal path. To show the effectiveness of themethod it is compared with some other methods in this area

    The study of enrichment capability of adult Artemia franciscana with singular or combined administration of Pediococcus acidilactici and fructooligosaccharide

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    The present study investigates the possibility of enriching adult Artemia franciscana with singular or combined administration of Pediococcus acidilactici and fructooligosaccharide (FOS). The experiment was conducted in a completely randomized design with four treatments, including synbiotic, P. acidilactici +FOS (T1), probiotic, P. acidilactici (T2), prebiotic, FOS (T3) and control (T4). To evaluate the enrichment of adult Artemia with each treatment, sampling was performed at 2, 4 and 6 hrs post enrichment. The bacterial counts was measured using the microbial culture and expressed as log CFU per g Artemia. A pre-experiment has been designed and probiotic was used in three levels (107, 108 and 109 CFU per litter of suspension) and prebiotic was used in three levels of 1, 2 and 5 g per litter of suspension. Based on pre experiment results, 108 CFU per litter of probiotic and 5 g per litter of prebiotic was selected. The results of this experiment showed that over time, consumed bacteria increased by adult Artemia and there was a significant difference between sampling in terms of ingested bacteria. The highest bacterial count (6.78±0.03 log CFU g-1) was observed 6 hrs after the start of enrichment. Based on microbial culture, the number of bacteria P. acidilactici in T1 and T2 was significantly higher than those in T4 (control) and T3 (prebiotic). There was no significance difference between T2 (probiotic) and T1 (synbiotic). In conclusion, the results of this study showed that adult Artemia in a short time (about 4 hrs) can retain a large amount of probiotic bacteria

    Target threat assessment using fuzzy sets theory

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    The threat evaluation is significant component in target classification process and is significant in military and non military applications. Small errors or mistakes in threat evaluation and target classification especial in military applications can result in huge damage of life and property. Threat evaluation helps in case of weapon assignment, and intelligence sensor support system. It is very important factor to analyze the behavior of enemy tactics as well as our surveillance. This paper represented a precise description of the threat evaluation process using fuzzy sets theory. A review has been carried out regarding which parameters that have been suggested for threat value calculation. For the first time in this paper, eleven parameters are introduced for threat evaluation so that this parameters increase the accuracy in designed system. The implemented threat evaluation system has been applied to a synthetic air defense scenario and four real time dynamic air defense scenarios. The simulation results show the correctness, accuracy, reliability and minimum errors in designing of threat evaluation syste

    Immunomodulation and Generation of Tolerogenic Dendritic Cells by Probiotic Bacteria in Patients with Inflammatory Bowel Disease

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    In inflammatory bowel diseases (IBD), the therapeutic benefit and mucosal healing from specific probiotics may relate to the modulation of dendritic cells (DCs). Herein, we assessed the immunomodulatory effects of four probiotic strains including Lactobacillus salivarius, Bifidobacterium bifidum, Bacillus coagulans and Bacillus subtilis natto on the expression of co-stimulatory molecules, cytokine production and gene expression of signal-transducing receptors in DCs from IBD patients. Human monocyte-derived DCs from IBD patients and healthy controls were exposed to four probiotic strains. The expression of co-stimulatory molecules was assessed and supernatants were analyzed for anti-inflammatory cytokines. The gene expression of toll-like receptors (TLRs), IL-12p40 and integrin \u3b1v\u3b28 were also analyzed. CD80 and CD86 were induced by most probiotic strains in ulcerative colitis (UC) patients whereas only B. bifidum induced CD80 and CD86 expression in Crohn's disease (CD) patients. IL-10 and TGF-\u3b2 production was increased in a dose-independent manner while TLR expression was decreased by all probiotic bacteria except B. bifidum in DCs from UC patients. TLR-4 and TLR-9 expression was significantly downregulated while integrin f8 was significantly increased in the DCs from CD patients. IL-12p40 expression was only significantly downregulated in DCs from CD patients. Our findings point to the general beneficial effects of probiotics in DC immunomodulation and indicate that probiotic bacteria favorably modulate the expression of co-stimulatory molecules, proinflammatory cytokines and TLRs in DCs from IBD patients

    Identifying teamwork-related needs of the medical emergency team: Nurses' perspectives

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    © 2021 The Authors. Background The role of medical emergency team (MET) in managing deteriorating patients and enhancing patient safety is greatly affected by teamwork. Aims To identify teamwork-related needs of the MET from MET nurses' perspectives. To assess the associations between MET nurses' perceptions of teamwork and their work experience and education. Study design A quantitative, descriptive correlational design. Methods Registered intensive care unit (ICU) nurses (n = 50) who were members of the MET in an acute tertiary care hospital answered a modified version of the team assessment questionnaire in 2017. Data were analysed using descriptive statistics, the Kruskal-Wallis test, and the univariate analysis of variance method. The reporting of this study adheres to the strengthening the reporting of observational studies (STROBE) guidelines. Results Participants showed least agreement with the items presenting leadership skills (mean = 2.6, SD = 0.68). Approximately 50% nurses disagreed that the MET had adequate resources, training, and skills. The majority of nurses (80%) felt that their responsibilities as a MET member interfered with taking care of their own ICU patients. Many nurses (64%) felt that they did not have a voice in MET's decision-making process. Approximately 50% nurses felt that they were not recognized for their individual contribution, and they were uncertain regarding MET's policies for dealing with conflicts. The amounts of MET nurses' work experience and education were associated with MET skills and function, respectively. Conclusion Key teamwork elements of the MET that need improvements include decision-making and conflict resolution skills, valuing team members, and team leadership. Practicing shared mental models, implementing the TeamSTEPPS curricula at hospitals for training ICU nurses, and simulation-based team-training programmes may be beneficial in improving teamwork of MET members. Relevance to clinical practice This study revealed key teamwork elements of the MET that need improvements. Our findings may contribute to improve teamwork, thereby optimizing MET function, and enhancing patient outcomes.Finnish Cultural Foundation North Savo region Funds. Grant Numbers: 2017, 2018; Finnish Nursing Education Foundation. Grant Number: 2016; Marja-Terttu Korhonen's Fund; Otto A. Malm Donations Funds; University of Eastern Finland. Grant Number: 201
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