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In the present study, fuzzy uncertainty and reliability analysis of aeroelastic aircraft wings are investigated. The uncertain air speed and structural parameters are represented by fuzzy triangular membership functions. These uncertainties are propagated through the wing model using a fuzzy interval approach, and the uncertain flutter speed is obtained as a fuzzy variable. Further, the reliability of the wing flutter is based on the interference area in the pyramid shape defined by the fuzzy flutter speed and air speed. The ratio between the safe region volume and the total volume of the pyramid gives the reliability value. Two different examples are considered—a typical wing section, and a clean wing—and the results are given for various wind speed conditions. The results show that the approach considered is a low-cost but suitable method to estimate the reliability of the wing flutter speed in the presence of uncertainties.
In this paper, two strategies are proposed to optimize the energy consumption of a new screw in-pipe inspection robot which is steerable. In the first method, optimization is performed using the optimal path planning and implementing the Hamilton–Jacobi–Bellman (HJB) method. Since the number of actuators is more than the number of degrees of freedom of the system for the proposed steerable case, it is possible to minimize the energy consumption by the aid of the dynamics of the system. In the second method, the mechanics of the robot is modified by installing some turbine blades through which the drag force of the pipeline fluid can be employed to decrease the required propulsion force of the robot. It is shown that using both of the mentioned improvements, that is, using HJB formulation for the steerable robot and installing the turbine blades can significantly save power and energy. However, it will be shown that for the latter case this improvement is extremely dependent on the alignment of the fluid stream direction with respect to the direction of the robot velocity, while this optimization is independent of this case for the former strategy. On the other hand, the path planning dictates a special pattern of speed functionality while for the robot equipped by blades, saving the energy is possible for any desired input path. The correctness of the modeling is verified by comparing the results of MATLAB and ADAMS, while the efficiency of the proposed optimization algorithms is checked by the aid of some analytic and comparative simulations.
The standard transthoracic echocardiography has some limitations in emergent and community-based situations. The emergence of pocket-sized ultrasound has led to influential advancements.
In this prospective study, in the hospital-based phase, children with suspected structural heart diseases were enrolled. In the school-based phase, healthy children were randomly selected from six schools. All individuals were examined by experienced operators using both the standard and the pocket-sized echocardiography.
A total of 73 individuals with a mean age of 9.9 ± 3.2 years in the hospital-based cohort and 143 individuals with a mean age of 12.8 ± 2.9 years in the school-based cohort were examined. The agreements between the standard and the pocket-sized echocardiography were good or excellent for major CHDs in both cohorts (κ statistics > 0.61). Among valvular pathologies, agreements for tricuspid and pulmonary valves’ regurgitation were moderate among school-based cohorts (0.56 [95% confidence interval 0.12–1] and 0.6 [95% confidence interval 0.28–0.91], respectively). The agreements for tricuspid and pulmonary valves’ regurgitation were excellent (>0.9) among hospital-based population. Other values for valvular findings were good or excellent. The overall sensitivity and specificity were 87.5% (95% confidence interval 47.3–99.7) and 93.8% (95% confidence interval 85–98.3) among the hospital-based individuals, respectively, and those were 88% (95% confidence interval 77.8–94.7) and 68.4% (95% confidence interval 56.7–78.6) among the school-based individuals, respectively. The cost of examination was reduced by approximately 70% for an individual using the pocket-sized device.
When interpreted by experienced operators, the pocket-sized echocardiography can be used as screening tool among school-aged population.
The aim of this study was to investigate the foraging behavior of Aphidius matricariae (Haliday) (Hymenoptera: Braconidae) as a biological control agent of Myzus persicae nicotianae Blackman (Hemiptera: Aphididae), a key and cosmopolitan pest of tobacco fields. To achieve a strategy for the control of this pest and a mass-rearing program of the parasitoid, host stage preference, switching, functional response, and mutual interference of A. matricariae were investigated at 25 ± 1°C, 70 ± 5% RH and 16:8 h L:D photoperiod. The parasitoid showed a preference for third- and fourth-instar nymphs of tobacco aphid in both choice and no-choice experiments. Using the Murdach's model, switching behavior was observed in A. matricariae between different density proportions of third- and fourth-instar nymphs. Further, the parasitoid exhibited a type II functional response when it was offered to third-instar nymphs of M. persicae nicotianae at six densities (2, 4, 8, 16, 32, and 64). Based on the linear regression analysis, there was a significance difference between the logarithm of per capita searching efficiency and the logarithm of parasitoid density. As the wasp density increased, per capita searching efficiency decreased. The result of this study revealed that A. matricariae is an effective agent in the integrated management of M. persicae nicotianae. In addition, application of these results can be important in mass-rearing program of A. matricariae.
Arboviruses are pathogens that widely affect the health of people in different communities around the world. Recently, a few successful approaches toward production of effective vaccines against some of these pathogens have been developed, but treatment and prevention of the resulting diseases remain a major health and research concern. The arbovirus infection and replication processes are complex, and many factors are involved in their regulation. Apoptosis, autophagy and the unfolded protein response (UPR) are three mechanisms that are involved in pathogenesis of many viruses. In this review, we focus on the importance of these pathways in the arbovirus replication and infection processes. We provide a brief introduction on how apoptosis, autophagy and the UPR are initiated and regulated, and then discuss the involvement of these pathways in regulation of arbovirus pathogenesis.
In this paper, a switchable antenna with capability to operate in ultrawideband (UWB) frequency from 3 to 10.7 GHz with two switchable notch bands of 3.3–3.7 and 3.7–4.2 GHz, is presented for cognitive radio (CR) and multiband orthogonal frequency-division multiplexing (MB-OFDM) applications. The proposed antenna has a simple structure and compact size of 17 × 24 mm2. The antenna in the UWB characteristics is obtained using a circular radiator patch with an embedded T-slot on the patch and a rectangular parasitic element that is attached to the patch. The reconfigurability is also achieved by two L-shaped parasitic elements placed in the left and right of the patch that two ideal switches is inserted over the these elements and the circular patch. The function of the antenna can be changed by tuning status of the switches that make the notch bands in application frequencies. The measurement and simulation results show that the antenna has good characteristics for CR application and MB-OFDM, where the UWB antenna is required for spectrum sensing and the switchable band rejection antenna is used for reconfigurable operation.
Mean residual life and failure rate functions are ubiquitously employed in reliability
analysis. The term of useful period of lifetime distributions of bathtub-shaped failure
rate functions is referred to the flat rigion of this function and has attracted authors
and researchers in reliability, actuary, and survival analysis. In recent years,
considering the change points of mean residual life and failure rate functions has been
extensively utelized in determining the optimum burn-in time. In this paper we investigate
the difference between the change points of failure rate and mean residual life functions
of some generalized gamma type distributions due to the capability of these distributions
in modeling various bathtub-shaped failure rate functions.
Let F be a bathtub-shaped (BT) hazard rate distribution function. It has been shown that the hazard rate function of the order statistics may be BT, increasing, etc. Then, we have carried out a graphical study for some useful lifetime models.
Moreover, we are interested to compare the time that maximizes the mean residual life (MRL) function of F with the one related to a general weighted model in terms of their locations. Also, the times maximizing the conditional reliability proposed by Mi  of F have been compared with the corresponding times of a general weighted model. As special cases, we consider order statistics and the proportional hazard rate model.
This paper presents the research work on a 1 degree of freedom (DOF) force reflecting tele-micromanipulation system. This system enables a human operator to position remote objects very precisely having haptic feedback. The slave robot is a nano-positioning piezo-actuator with hysteretic dynamics. This intrinsic nonlinearity results in positioning inaccuracy and instability. Hence, a LuGre friction model is employed to model and compensate for this undesirable behavior. By means of a transformation, the 2-DOF master–slave system (1-DOF each) is decomposed into two 1-DOF new systems: the shape system, representing the master–slave position coordination, and the locked system, representing dynamics of the coordinated system. A key innovation of this paper is to generalize this approach to the hysteresis-type nonlinear teleoperated systems. For the shape system, a position tracking controller is designed in order to achieve position coordination. This position coordination is guaranteed not only in free space motion, but also during contact at the slave side. Furthermore, a force tracking controller is designed for the locked system in order to achieve tracking of the force exerted on the master and slave robots. Using this force controller, transparency is remarkably enhanced. Based on the virtual flywheels concept, passivity of the closed-loop teleoperator is guaranteed against dynamic parameter uncertainties and force measurement inaccuracies. The simulation and experimental results verify the capability of the proposed control architectures in achieving high-level tracking of the position and force signals while the system remains stable.
Today the use of enzymes is common in practical poultry nutrition. Enzyme supplementation usually result in numerous beneficial effects, such as increased utilization of nutrients (e.g. fat & protein), improved AME values, increased growth rate, improved feed conversion ratio, decreased viscosity of intestinal digesta, reduced incidence of sticky excreta and improved litter conditions (Broz and Ward., 2007). The use of multi enzymes to improve the digestibility of corn-soybean meal-wheat diets for broilers is less well documented than wheat and barely diets. Therefore, the aim of the present study was to examine the effects of a multi-enzyme supplementation on the performance of broiler chicks fed on corn-soybean meal-wheat diets.
One hundred and nine patients with primary antibody deficiencies were selected in order to determine the frequency of ENT complications.
Demographic information and ENT medical histories were collected for each patient. Duration of study for each patient was divided into two periods of before diagnosis and after diagnosis and the initiation of treatment.
Eighty-two of 109 patients (75.2 per cent) experienced ENT infections during the course of the disease (63: otitis media, 75: sinusitis and nine: mastoiditis). At the time of diagnosis, 52 (47.7 per cent) out of 109 patients presented with an ENT symptom. The frequencies of episodes were 27 for sinusitis and 25 for otitis media (one complicated with mastoiditis). After immunoglobulin replacement therapy the incidence of otitis media was reduced from 1.75 before treatment to 0.39 after treatment per patient per year (p = 0.008). The incidence of sinusitis also significantly decreased from 2.38 to 0.78 (p value = 0.011).
ENT infections are common medical problems in primary antibody deficiency patients. Persistent and recurrent ENT infections should be suspected as originating from a possible underlying immunodeficiency.
Maize is the principal energy source in most poultry diet in developing countries. As the cultivating of maize is limited in Iran, annually a large amount of maize is imported. Broken rice (BR) is a major cereal by-product for animal feeding in rice-growing countries. The annual production of rice paddy in Iran is about 2 million tonnes. After milling of paddy, broken rice is available for utilization in animal diet. BR consists of 40 to 80 g/kg of rice paddy. It contains good sources of protein (100-110 g/kg), fat (60-110 g/kg), carbohydrate, fibre (20-50 g/kg). Due to mixing with bran and hull the chemical composition of BR varies in different samples. In some part of the country the price of this ingredient is lower than maize. The objective of the present experiment was to evaluate the effect diets containing different levels of BR on performance of broiler chicks from 1 to 8 weeks of age.
Soyabean meal (SBM) is used extensively in poultry rations. As the cultivation of soya bean is limited in Iran, annually a large amounts of SBM is imported. In recent years cultivation of some oil seed such as sunflower seed (Heliantus annus) is undertaken in some provinces of Iran. This plant will grow in cooler and dried climates than the soya bean or cotton plants. It contains 45 percent oil and a good source of protein and B-group vitamins. Due to high fibre content and low lysine content, use of sunflower meal (SSM) is limited in poultry feeds, but dehulled SSM is suitable for broiler feeds (Church, 1988 and Scott et al., 1982). The objective of the present study was to investigate the effect of SSM on performance of broiler chicken.
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