Minimum variance adaptive beamforming combined with coherence factor weighting applied to ultrafast active cavitation imaging

The ultrafast active cavitation imaging(UACI)based on plane wave transmission and delay-and-sum(DAS)beamforming has been developed to monitor cavitation events with a high frame rate.However,DAS beamforming leads to images with limited resolution and contrast.In this paper,minimum variance(M V)adaptive beamforming and coherence factor(CF)weighting are combined to achieve an MVCF-based UACI,which can improve the cavitation imaging quality.The detailed algorithm evaluation has been investigated from both simulation and experimental data The simulation data include10point targets and a cyst,while the experimental data are obtained by detecting the dissipation of cavitation bubbles in water excited by a single element transducer with frequency of1.2MHz.The advantages of the proposed methodology as well as the comparison with conventional B-mode,DAS?M V,DAS-CF and MV on the basis of compressive sensing(CS)(called MVCS)beamformers are discussed.The results show that MVCF beamformer has a significant improvement in terms of both resolutions and signal-to-noise ratio(SN R).The MVCF-based UACI has a SNR at21.82dB higher,lateral and axial resolution at2.69times and1.93times?respectively,which were compared with those of B-mode active cavitation mapping.The MVCF-based UACI can be used to image the residual cavitation bubbles with a higher SNR and better spatial resolution

Retrieval Single-Doppler Radar Wind with Variational Assimilation Method-Part I: Objective Selection of Functional Weighting Factors

In variational problem, the selection of functional weighting factors (FWF) is one of the key points for discussing many relevant studies. To overcome arbitrariness and subjectivity of the empirical selecting methods used widely at present, this paper tries to put forward an optimal objective selecting method of FWF. The focus of the study is on the weighting factors optimal selection in the variation retrieval single-Doppler radar wind field with the simple adjoint models. Weighting factors in the meaning of minimal variance are calculated out with the matrix theory and the finite difference method of partial differential equation. Experiments show that the result is more objective comparing with the factors obtained with the empirical method.

New weighting factors assignment of evidence theorybased one vidence distance

Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict information exists. Based on the analysis of some modified methods, Assigning the weighting factors according to the intrinsic characteristics of the existing evidence sources is proposed, which is determined on the evidence distance theory. From the numerical examples, the proposed method provides a reasonable result with good convergence efficiency. In addition, the new rule retrieves to the Yager's formula when all the evidence sources contradict to each other completely.

Weight Determining of Factors Influencing Grain Output Based on Entropy Weight Method

This article selects 8 main factors(the number of rural employees,total power of agricultural machinery,effective irrigation area of crops,growing area of grain crops,fertilizer consumption,electricity consumption in rural areas,area affected and area covered) as the factors influencing grain output,and offers the method of determining weight of factors influencing grain output using entropy weight method.According to the relevant data in the period 1985-2005,we analyze the weight of factors influencing grain output in China by example.The results show that the electricity consumption in rural areas has the greatest impact on grain output,followed by total power of agricultural machinery,fertilizer consumption and area covered.To increase grain output,we must enhance the degree of mechanization,free people from the former process of direct cultivation,strengthen water conservancy construction,and do a good job in disaster prevention and mitigation.

Time Domain Full Waveform Inversion Based on Gradient Preconditioning with an Angle-Dependent Weighting Factor

There are lots of low wavenumber noises in the gradients of time domain full waveform inversion(FWI),which can seriously reduce the accuracy and convergence speed of FWI.Thus,we introduce an angle-dependent weighting factor to precondition the gradients so as to suppress the low wavenumber noises when the multi-scale FWI is implemented in the high frequency.Model experiments show that the FWI based on the gradient preconditioning with an angle-dependent weighting factor has faster convergence speed and higher inversion accuracy than the conventional FWI.The tests on real marine seismic data show that this method can adapt to the FWI of field data,and provide high-precision velocity models for the actual data processing.

An Improved Bald Eagle Search Algorithm with Cauchy Mutation and Adaptive Weight Factor for Engineering Optimization

The Bald Eagle Search algorithm(BES)is an emerging meta-heuristic algorithm.The algorithm simulates the hunting behavior of eagles,and obtains an optimal solution through three stages,namely selection stage,search stage and swooping stage.However,BES tends to drop-in local optimization and the maximum value of search space needs to be improved.To fill this research gap,we propose an improved bald eagle algorithm(CABES)that integrates Cauchy mutation and adaptive optimization to improve the performance of BES from local optima.Firstly,CABES introduces the Cauchy mutation strategy to adjust the step size of the selection stage,to select a better search range.Secondly,in the search stage,CABES updates the search position update formula by an adaptive weight factor to further promote the local optimization capability of BES.To verify the performance of CABES,the benchmark function of CEC2017 is used to simulate the algorithm.The findings of the tests are compared to those of the Particle Swarm Optimization algorithm(PSO),Whale Optimization Algorithm(WOA)and Archimedes Algorithm(AOA).The experimental results show that CABES can provide good exploration and development capabilities,and it has strong competitiveness in testing algorithms.Finally,CABES is applied to four constrained engineering problems and a groundwater engineeringmodel,which further verifies the effectiveness and efficiency of CABES in practical engineering problems.

LDFF,the large molecular weight DNA fragmentation factor,is responsible for the large molecular weight DNA degradation during apoptosis in Xenopus egg extracts

DNA degradation is a biochemical hallmark in apoptosis. It has been demonstrated in many cell types that there are two stages of DNA fragmentation during the apoptotic execution. In the early stage, chromatin DNA is cut into large molecular weight DNA fragments, although the responsible nuclease(s) has not been recognized. In the late stage, the chromatin DNA is cleaved further into short oligonucleosomal fragments by a well-characterized nuclease in apoptosis,the caspase-activated DNase (CAD/DFF40). In this study, we demonstrate that large molecular weight DNA fragmentation also occurs in Xenopus egg extracts in apoptosis. We show that the large molecular weight DNA fragmentation factor (LDFF) is not the Xenopus CAD homolog XCAD. LDFF is activated by caspase-3. The large molecular weight DNA fragmentation activity of LDFF is Mg2+-dependent and Ca2+-independent, can occur in both acidic and neutral pH conditions and can tolerate 45℃ treatment. These results indicate that LDFF in Xenopus egg extracts might be a new DNase (or DNases) responsible for the large DNA fragmentation.

Risk Factors for Low Birth Weight and Preterm Birth：A Population-based Case-control Study in Wuhan,China

Low birth weight（LBW） and preterm birth（PB） are associated with newborn mortality and diseases in adulthood.We explored factors related to LBW and PB by conducting a population-based case-control study from January 2011 to December 2013 in Wuhan,China.A total of 337 LBW newborn babies,472 PB babies,and 708 babies with normal birth weights and born from term pregnancies were included in this study.Information of newborns and their parents was collected by trained investigators using questionnaires and referring to medical records.Univariate and logistic regression analyses with the stepwise selection method were used to determine the associations of related factors with LBW and PB.Results showed that maternal hypertension（OR=6.78,95% CI：2.27–20.29,P=0.001）,maternal high-risk pregnancy（OR=1.53,95% CI：1.06–2.21,P=0.022）,and maternal fruit intake ≥300 g per day during the first trimester（OR=1.70,95% CI：1.17–2.45,P=0.005） were associated with LBW.BMI ≥24 kg/m^2 of mother prior to delivery（OR=0.48,95% CI：0.32–0.74,P=0.001） and gestation ≥37 weeks（OR=0.01,95% CI：0.00–0.02,P〈0.034） were protective factors for LBW.Maternal hypertension（OR=3.36,95% CI：1.26–8.98,P=0.016）,maternal high-risk pregnancy（OR=4.38,95% CI：3.26–5.88,P〈0.001）,maternal meal intake of only twice per day（OR=1.88,95% CI：1.10–3.20,P=0.021）,and mother liking food with lots of aginomoto and salt（OR=1.60,95% CI：1.02–2.51,P=0.040） were risk factors for PB.BMI ≥24 kg/m^2 of mother prior to delivery（OR=0.66,95% CI：0.47–0.93,P=0.018）,distance of house from road ≥36 meters（OR=0.72,95% CI：0.53– 0.97,P=0.028）,and living in rural area（OR= 0.60,95% CI：0.37–0.99,P=0.047） were protective factors for PB.Our study demonstrated some risk factors and protective factors for LBW and PB,and provided valuable information for the prevention of the conditions among newborns.

Maternal risk factors for low birth weight for term births in a developed region in China:a hospital-based study of 55,633 pregnancies

Low birth weight （LBW） is an important risk factor for neonatal and infant mortality and morbidity in adults.. How- ever, no large scale study on the prevalence of LBW and related maternal risk factors in China has been published. To explore the effects of maternal factors on LBW for term birth in China, we conducted a hospital-based retrospective study of 55, 633 Chinese pregnancy cases between 2001 and 2008. Maternal sociodemographic data, history of infer- tility and contraceptive use were obtained. Their medical status and diseases during pre-pregnancy were examined by physical examination at the first antenatal care visit. Maternal medical status before childbirth and pregnancy outcomes, including body weight, infant gender, multiple pregnancy and congenital anomalies, were recorded. Univariate and multivariate logistic regression, and linear regression were used to investigate the relationship be- tween maternal factors and term LBW. The general incidence of term LBW was 1.70% in the developed area of China. After preliminary analysis using the univariate model, low primary education, anemia, hypertensive disor- ders, placental previa, oligohydramnios and premature rupture of membrane were predicted as independent factors of term LBW in the multivariate model. Furthermore, the decrease in annual frquencies of these risk factors were major causes of gradual decline in the incidence of LBW （from 2.43% in 2001 to 1.21% in 2008）. The study dem- onstrated that among maternal factors, primary education, anemia and hypertensive disorders could contribute to LBW for term birth even in the most developed area of China.

SEMI-WEIGHT FUNCTION METHOD ON COMPUTATION OF STRESS INTENSITY FACTORS IN DISSIMILAR MATERIALS

Semi_weight function method is developed to solve the plane problem of two bonded dissimilar materials containing a crack along the bond. From equilibrium equation, stress and strain relationship, conditions of continuity across interface and free crack surface, the stress and displacement fields were obtained. The eigenvalue of these fields is lambda. Semi_weight functions were obtained as virtual displacement and stress fields with eigenvalue?_lambda. Integral expression of fracture parameters, K Ⅰ and K Ⅱ, were obtained from reciprocal work theorem with semi_weight functions and approximate displacement and stress values on any integral path around crack tip. The calculation results of applications show that the semi_weight function method is a simple, convenient and high precision calculation method.

Problem of the reference height of the projectile trajectory as a reduced meteo-ballistic weighting factor

This paper deals with the issue of preparation of the aiming angles with the use of tabular firing tables and needed determination of the ballistic elements μ_B(ballistic wind w_B,w_(xB),w_(ZB),ballistic(virtual) temperature τ_B.ballistic density p_B) from the standardized met messages.The weighting factors are used for the calculation of ballistic elements μ_B that are incorporated into the trajectory calculations characteristics of weapon and ammunition.Two different methodologies practically used in the praxis are analysed and compared.For the comparison of the two methodologies the reference height of trajectory determined from the weighting factor functions is employed.On the basis of the analyses conducted,the potential for further increase in accuracy of these aiming angles preparation methods is pointed out.

A WEIGHTED RESIDUAL METHOD FOR ELASTIC-PLASTIC ANALYSIS NEAR A CRACK TIP AND THE CALCULATION OF THE PLASTIC STRESS INTENSITY FACTORS

In this paper, a weighted residual method for the elastic-plastic analysis near a crack tip is systematically given by taking the model of power-law hardening under plane strain condition as a sample. The elastic-plastic solutions of the crack lip field and an approach based on the superposition of the nonlinear finite element method on the complete solution in the whole crack body field, to calculate the plastic stress intensity factors, are also developed. Therefore, a complete analvsis based on the calculation both for the crack tip field and for the whole crack body field is provided.

Model Predictive Yaw Control Using Fuzzy-Deduced Weighting Factor for Large-Scale Wind Turbines

Yaw control system plays an important role in helping large-scale horizontal wind turbines capture the wind energy.To track the stochastic and fast-changing wind direction,the nacelle is rotated by the yaw control system.Therein,a difficulty consists in the variation speed of the wind direction much faster than the rotation speed of the nacelle.To deal with this difficulty,model predictive control has been recently proposed in the literature,in which the previewed wind direction is employed into the predictive model,and the estimated captured energy and yaw actuator usage are two contradictive objectives.Since the performance of the model predictive control strat-egy relies largely on the weighting factor that is designed to balance the two objectives,the weighting factor should be carefully selected.In this study,a fuzzy-deduced scheme is proposed to derive the weighting factor of the mod-el predictive yaw control.For the proposed fuzzy-deduced strategy,the variation degree and the increment of the wind direction during the predictive horizon are used as the inputs,and the weighting factor is the output,which is dynamically adjusted.The proposed model predictive yaw control is demonstrated by some simulations using real wind data and its performance is compared with the conventional model predictive control with thefixed weighting factor.Comparison results confirm the outweighing performance of the proposed control strategy over the conventional one.

Improved theory of generalized meteo-ballistic weighting factor functions and their use

It follows from the analysis of artillery fire errors that approximately two-thirds of the inaccuracy of indirect artillery fire is caused by inaccuracies in the determination of the meteo parameters included in fire error budget model.Trajectories calculated under non-standard conditions are considered to be perturbed.The tools utilized for the analysis of perturbed trajectories are weighting factor functions(WFFs)which are a special kind of sensitivity functions.WFFs are used for calculation of meteo ballistic elements B(ballistic wind w B,densityρB,virtual temperatureτB,pressure p B)as well.We have found that the existing theory of WFF calculation has several significant shortcomings.The aim of the article is to present a new,improved theory of generalized WFFs that eliminates the deficiencies found.Using this theory will improve methods for designing firing tables,fire control systems algorithms,and meteo message generation algorithms.

Weight Function Method for Stress Intensity Factor of Internal Surface Semi-elliptical Crack in Elliptical Holes

The hatches for inspecting are usually designed with elliptical holes in airplane structures, so computation of the stress intensity factor of three dimensional crack at elliptical holes is pivotal for damage tolerance analysis of these structures. In this paper, weight function is derived for a two dimensional through cracks at elliptical holes by applying a compounding method. Stress intensity factor formulas for an internal surface semi-elliptical crack in elliptical holes are obtained wing the three dimensional weight function method. Stress intensity factors for an internal surface semi-elliptical crack in elliptical holes under remote tension are computed. At the same time, research on how radius of curvature for elliptical holes affect stress intensity factors was conducted. Stress intensity factors decrease when radius of curvature increases. Some results and conclusions which are of practical value are given.

Effects of Orlistat - induced Weight Loss on Cardiovascular Risk Factors in Obese Chinese Subjects

Objectives To observe the influence of weight loss induced by orlistat on several cardiovascular diseases risk factors in obese Chinese subjects. Methods Sixty obese Chinese patients participated in a 24 week clinical trial. Participants were prescribed a slightly hypocaloric diet and exercise, then they were randomly assigned double -blind treatment with either orlistat 120 mg three times a day or placebo. Their body weight, blood pressure, fasting glucose, insulin, HbA1c, and serum lipid profile were performed before and after the weight loss intervention. Results After 24 weeks, orlistat -treated group lost more of their body weight than placebo group (6. 66 ± 0. 52 kg, 8. 44±4.08% and 1. 98 ± 0. 44 kg, 2. 44±1. 74 % , respectively, P < 0. 05) . Moreover, after treatment, orlistat - treated patients showed significant decreases in serum levels of total cholesterol, low density lipoprotein - cholesterol and high density lipoprotein - cholesterol ( P < 0.01), but in placebo group we found no change. Both systolic blood pressure and diastolic blood pressure fell significantly in orlistat - treated group. Fasting glucose and HOMA - IR in orlistat - treated group was distinctly reduced if compared with placebo group. Conclusions Weight loss resulting from orlistat treatment and slightly hypocaloric diet has produced favorable effects on several cardiovascular risk factors in obese Chinese subjects.

Factors of Low Birth Weight Risk in the Department of Gynecology-Obstetrics of the Ignace Deen National University Teaching Hospital in Conakry, Guinea

Introduction: The underweight at birth is recognized as a major cause of morbidity and mortality in childhood. Objective: To identify maternal and obstetric sociodemographic factors associated with low birth weight. Patients and Methods: This is a retrospective study of analytical type that examined the records of women who gave birth in the Obstetrics and Gynecology department of Ignace Deen National University Teaching Hospital from 1st December 2016 to 30th April 2017. The analysis was made with the R version 3.3.1 software. We did a univariate and multivariate analysis. Outcomes: Out of the 1633 live births of single pregnancies that occurred during the study period, 109 children were born with a low weight (<2500 g) corresponding to a rate of 6.7%. In univariate analysis, we found a significant association between low birth weight and maternal single status (p = 0.019), maternal weight less than 60 kg (p = 0.038), primary parity (p = 0.018), maternal history of abortion (p = 0.001), history of preterm birth (p < 0.001), arterial hypertension (p < 0.001), anemia (p < 0.001) and malaria (p < 0.001). In multivariate analysis, the variables associated with low birth weight were: history of preterm delivery with OR of 8.5 [1.8 - 40.1], history of abortion (OR = 4.4 [1.4 - 13.9]), malaria (OR = 23.8 [6.1 - 92.5]), anemia (OR = 11.8 [3.7 - 38.2]) and high blood pressure (OR = 5.4 [1.6 - 17.9]). Conclusion: The decrease in frequency of low birth weight in Guinea will be done by improving the quality of prenatal care with an emphasis on screening, prevention and treatment of malaria, anemia and high blood pressure during pregnancy, prevention of abortion and premature birth.

Individual Cotton Boll Weight as Influenced by Different Production Eco-Regions and Meteorological Factors

In order to explore systematically the physiological mechanism of high yield cotton ( Gossypium hirsutum L.) in Xinjiang, and further improve yield, the yield components were compared between three ecological regions. Boll number per plant was lower in South and North Xinjiang, but the harvested plant population were nearly 1.5 times higher than that in Nangong, so total boll numbers per unit area were greater in South and North Xinjiang. Weight per boll in south and north of Xinjiang was 5.896.50 g and 5.43 6.12 g respectively, 24 to 51% heavier than that in Nangong. The diurnal temperature difference between day and night was relatively greater in Xinjiang than in Nangong, benefitting the accumulation of photosynthetic product in bolls. The temperature difference and total hours of sunshine in boll period are the main reasons for cottons higher boll weight and yield in Xinjiang than in Nangong.

Low Birth Weight at Term: Risk Factors and Perinatal Prognosis in the Teaching Hospital Yalgado Ouédraogo, Burkina Faso

Objective: The objective of our study was to study the risk factors of low birth weight at term in the Teaching Hospital Yalgado (CHU-YO) Ouédraogo. Patients and Methods: This dealt with a comparative and analytical control case study. The group of cases was made up of female patients who gave birth to newborns with low birth weight at term and that of control cases included female patients who delivered a normal-weighted newborn at term. Results: The frequency of low birth weight at term was therefore estimated at 4.4%. The average age of the parturients was 25 ± 6.36 years. Female patients living in a marital setting accounted for 93.1% of cases and 64.4% of them had no income-generating activities. A maternal underweight, a height below 155 cm, passive smoking, and malaria during pregnancy have been identified as the factors associated with a low birth weight. Conclusion: Quality prenatal care could reduce the incidence of low birth weight at term.

Passive Smoking and Other Principal Risk Factors Associated with Low Birth Weight

Background: Neonatal morbidity and mortality is one of the most public health problems in the world. A lot of neonatal deaths occur in foetus with low birth weight (LBW). Several risk factors of LBW have been described in the literature such as maternal age, chronic and gestational hypertension infection and anémia. Smoking is one of the most important preventable risk factor of LBW in developed and developing countries. Aims: In this study, we evaluated the incidence and the impact of passive smoking and some other principle risk factors of LBW. Material & Methods: This case control study was conducted in the department of obstetrics and gynecology of Marrakesh university hospital in Morocco. During a period of 3 years, all LBW babies were included in the study. Data analysis was performed by SPSS software. The association between LBW and each variable was studied by the chi square test comparing cases and controls groups. Logistic regression analysis was performed after including all variables found to have significant differences on univariate analysis. Results: 288 cases of LBW have been identified representing 2.19% of all births. The study of the categories showed that 84.3% of babies were moderate LBW (1500 - 2500 g), including 49 babies from twin pregnancies. 15.7% were very LBW (<1500 g). Several risk factors have been identified in LBW. Passive smoking was significantly associated with LBW [(OR 1.77;CI: 1.22 - 2.25)]. Conclusion: A number of risk factors are related to low birth weight, which is one of the main predictors of infant mortality. This study shows that passive smoking is one of those risk factors and it is a preventable one.