Interval Mean Value Research Articles

Hybrid uncertainty analysis of functionally graded plates via multiple-imprecise-random-field modelling of uncertain material properties

This paper presents the mixed probabilistic/non-probabilistic uncertainty problem regarding the hybrid uncertainty propagation on physical model of functionally graded plates through dissimilarly uncertain characterisation of material properties in the presence of the multiple-imprecise-random-field modelling. The spectral stochastic finite element framework is extended to perform mixed uncertainty analysis of functionally graded material whereby the spatial variation of elastic modulus of the plate is uniquely characterised as the multiple-imprecise-random-field modelling more than a purely homogeneous random field. This characterisation has originated in heeding the construction of physical models and the significant influences of separately uncertain characteristics propagated on the physical model through different material ingredients are examined to make physical models more reliable and realistic. Mechanics and mathematics intrusive-formulations are then established to explicitly produce the uncertain-but-bounded statistical characteristics of responses, namely interval mean value, interval standard deviation. Bounded surfaces of statistical moments and bounding distribution functions are vividly depicted for demonstration. The feasibility and effectiveness of the presented work are illustrated via test cases of numerical examples.

Propagation of uncertain structural properties described by imprecise Probability Density Functions via response surface method

The present study addresses the analysis of structures with uncertain properties modelled as random variables characterized by imprecise Probability Density Functions (PDFs), namely PDFs with interval basic parameters (mean-value, variance, etc.). Due to imprecision in the probabilistic model, the statistics of the response and the failure probability are described by interval quantities. An efficient procedure for evaluating the bounds of such quantities is developed. The proposed method stems from the application of a ratio of polynomial response surface (Impollonia and Sofi, 2003; Sofi and Romeo, 2018) in conjunction with the classical probabilistic analysis and the so-called Improved Interval Analysis via Extra Unitary Interval (IIA via EUI) (Muscolino and Sofi, 2012). Interval response statistics are derived as approximate explicit functions of the interval parameters describing imprecise probabilities. The range of the interval failure probability is estimated in terms of the interval reliability index once the bounds of the interval mean-value and variance of the response are evaluated.Numerical results concerning a frame structure and a grid structure with uncertain Young’s moduli characterized by imprecise PDFs are presented. The accuracy of the proposed method along with the influence of randomness and imprecision of the input parameters on response statistics and reliability assessment are investigated.

Acute Fingolimod Effects on Baroreflex and Cardiovascular Autonomic Control in Multiple Sclerosis.

Background:Fingolimod, an oral drug used in multiple sclerosis (MS) treatment, exerts its action through S1P-receptor engagement. These receptors are also expressed in heart and endothelial cells. The engagement of receptors on the atrial heart myocytes may cause a slowing effect on heart rate (HR). We aimed to explore the acute effect of fingolimod on the cardiac autonomic control, a side-effect of the drug that still needs to be clarified.Methods:In 10 MS patients, we investigated the influence of the first administration of fingolimod (0.5 mg) on sympathetic and parasympathetic indexes via the analysis of the HR variability, and on the baroreflex sensitivity via sequence and alpha coefficient techniques.Results:Fingolimod produced an average HR maximal drop of 12.7 (7.8) beats/min and the minimal HR occurred after 2.73 (0.38) hours from the dose administration. The pulse interval (PI) mean value and the pNN50 and RMSSD indexes of parasympathetic drive to the heart significantly increased. Interestingly, in 6 out of 10 patients also the power in the low-frequency band (LF) increased. The baroreflex sensitivity was not modified by the first dose of the drug.Conclusions:Our findings indicate that although the first dose of fingolimod invariably activates the parasympathetic system, in several subjects, it may induce also a surge in the sympathetic cardiac drive. This suggests that not only the vagal, as usually assumed, but also the sympathetic autonomic branch should be considered in the risk profile assessment of MS patients starting treatment with fingolimod.

Hybrid evidence-and-fuzzy uncertainty propagation under a dual-level analysis framework

With the development of modern computing technology, the uncertainty propagation theory plays an increasing important role in the thermal engineering practice. Under this context, our paper proposes an efficient dual-level framework for hybrid uncertainty propagation analysis. Two kinds of epistemic uncertainties are considered simultaneously in inputs, which are respectively modeled as evidence parameters with basic probability assignment and fuzzy parameters with membership function. The hybrid uncertainty characteristic of output response is interpreted by the interval-type mean value with fuzzy bounds, where the interval mean value is derived by focal element subintervals in the first-level evidence uncertainty analysis, and the membership function of fuzzy bounds is constructed by cut-set operation in the second-level fuzzy uncertainty analysis. In order to enhance the computational efficiency for cross-extreme-value prediction, a dual-level parameter perturbation method (DPPM) with small computational cost is developed, where the subinterval dividing strategy can be adopted in sub-DPPM to further improve the computational precision. By comparing results with the direct optimization method, two examples prove the effectiveness of proposed method in engineering application.

PO-149 Taekwondo Exercise Improving Cardiopulmonary Function of Female College Students after 16 Weeks Intervention

Objective Taekwondo is one of the popular exercise styles to promote aerobic endurance for college students because of its combination of hands and feet and simple technology and interesting. This study observed the effect of Taekwondo on the cardiopulmonary function of female college students, trying to find the best heart rate in the teaching class of Taekwondo and evaluate the effect of maximal oxygen uptake and improve the basic theory of Taekwondo exercise to enhance students' aerobic endurance and provide theoretical reference for scientific methods to improve classroom practice intensity.
 Methods 1)This study used heart rate telemetry to perform a time domain analysis of heart rate variability in 10 university students in the Taekwondo class. The indicators used in the time domain analysis are: average RR interval value, standard deviation of RR interval (SDNN), standard deviation of the average of every 5 minutes R-R interval (SDANN), and standard deviation of R-R interval every 5 minutes The mean value (SDNNindex), the difference between adjacent NNs> the percentage of the number of total sinus beats per 50 ms (PNN50). By analyzing the information of these indicators, the sympathetic and vagal nerves are balanced. 2) The maximum oxygen uptake and respiratory exchange rate of 10 female college students were measured by the treadmill exercise load per breath method. The cardiopulmonary function of female college students was assessed by cardiopulmonary function indicators and heart rate variability indicators.
 Results 1) The R-R interval value, the mean value of the R-R interval standard deviation (SDNNindex), and the standard deviation (SDANN) of the R-R interval mean value per 5 min were increased after exercise intervention. The three indicators increased by 438.22ms, 0.87ms, and 64.67 ms, respectively; The standard deviation of the R-R interval (SDNN), the difference between adjacent NNs >50ms, the percentage of total sinus beats (PNN50) decreased.They dropped by 44.23ms and 0.06% respectively. With the increase of the sports load of Taekwondo students, the heart rate variability gradually decreases, showing a decline in the vagus nerve tension of female college students.2) The average relative oxygen uptake of female college students before the start of the course was 30.7ml (kg*min), 35 ml (kg*min) after the intervention, and the maximum oxygen uptake increased by 14.01%. The average respiratory exchange rate of female college students before the start of the course was 1.26, 1.28 after the course intervention, and the respiratory exchange rate increased by 1.59%.
 Conclusions 1) Taekwondo exercise reduces the heart rate variability of female college students, and long-term exercise can enhance the ability of the vagus nerve to control the heart. 2) Increased maximal oxygen uptake and respiratory exchange rate of female college students through Taekwondo course intervention.After a long period of Taekwondo exercise, it can effectively improve the aerobic endurance of college students and improve their cardiopulmonary function.（NSFC：31401018 SKXJX2014014).

Correlations of the von Mangoldt and higher divisor functions I. Long shift ranges

We study asymptotics of sums of the form ∑ X < n ⩽ 2 X Λ ( n ) Λ ( n + h ) , ∑ X < n ⩽ 2 X d k ( n ) d l ( n + h ) , ∑ X < n ⩽ 2 X Λ ( n ) d k ( n + h ) , and ∑ n Λ ( n ) Λ ( N − n ) , where Λ is the von Mangoldt function, d k is the kth divisor function, and N , X are large. Our main result is that the expected asymptotic for the first three sums holds for almost all h ∈ [ − H , H ] , provided that X σ + ε ⩽ H ⩽ X 1 − ε for some ε > 0 , where σ : = 8 33 = 0.2424 ⋯ , with an error term saving on average an arbitrary power of the logarithm over the trivial bound. This improves upon results of Mikawa and Baier–Browning–Marasingha–Zhao, who obtained statements of this form with σ replaced by 1 3 . We obtain an analogous result for the fourth sum for most N in an interval of the form [ X , X + H ] with X σ + ε ⩽ H ⩽ X 1 − ε . Our method starts with a variant of an argument from a paper of Zhan, using the circle method and some oscillatory integral estimates to reduce matters to establishing some mean-value estimates for certain Dirichlet polynomials associated to ‘Type d 3 ’ and ‘Type d 4 ’ sums (as well as some other sums that are easier to treat). After applying Hölder's inequality to the Type d 3 sum, one is left with two expressions, one of which we can control using a short interval mean value theorem of Jutila, and the other we can control using exponential sum estimates of Robert and Sargos. The Type d 4 sum is treated similarly using the classical L 2 mean value theorem and the classical van der Corput exponential sum estimates. In a sequel to this paper we will obtain related results for the correlations involving d k ( n ) for much smaller values of H but with weaker bounds.

Developing English Speaking Learning Materials for Saturday English School Program

This study aims at (1) identifying the target needs, and learning needs of students, (2) developing appropriate English speaking learning materials for grade VII students of SES Program at SMPIT ABY. This research was a research and development study consisting of seven steps: needs analysis, developing course grid, developing first draft, getting the expert judgment, trying out the materials, evaluating and revising the materials, and writing the final draft. The subjects were grade VII students of SES Program at SMPIT ABY. The data were collected using questionnaires and an interview guide. The results found that the target needs of grade VII students of SES program at SMPIT ABY are the English speaking learning materials which are related to Islamic contents. Their learning needs are related to the goal, input, setting, procedure, teachers’ role, and students’ role. Four units were developed based on the target and learning needs. The interval mean value of each task component in all units of the developed materials is between 2.52&lt; Ẍ ≤ 3.27and 3.28 &lt; Ẍ ≤ 4.03. This indicates that, the materials are appropriate to grade VII students of SES Program at SMPIT ABY.Keywords: speaking, learning materials and saturday English school program

Stochastic finite element analysis of structures in the presence of multiple imprecise random field parameters

The research work presents the study on non-deterministic problems in the presence of the multiple imprecise-random-field uncertainties by extending the spectral stochastic finite element framework. The standard random field is expanded to characterize the behaviour of physical model with imprecise randomness more appropriately for real engineering problems based on available sources of uncertainty. The Young’s modulus and body force of structures are considered as imprecise random fields with bounded statistical moments. Mathematical expressions and solution procedure are developed to produce the uncertain-but-bounded statistical characteristics of responses, namely interval mean value, interval standard deviation and bounding distribution functions. The bounding probability density and cumulative distribution of the imprecise random response are then effectively visualized by means of Polynomial Chaos Expansion. The feasibility and effectiveness of the presented method are illustrated by three numerical examples.

Reliability analysis of structures with interval uncertainties under stationary stochastic excitations

Reliability analysis of linear discretized structural systems with interval uncertainties subjected to stationary Gaussian random excitation is addressed. Under the assumption of independent up-crossings of a specified threshold, an efficient procedure for the evaluation of the bounds of the interval reliability function of the generic response process is presented. The first step of the proposed approach is to derive approximate expressions of the interval mean-value and spectral moments of the response along with the associated bounds. To this aim, the improved interval analysis via extra unitaryinterval is applied in conjunction with a novel series expansion of the inverse of an interval matrix with modifications, called Interval Rational Series Expansion (IRSE). Then, the lower bound and upper bounds of the interval reliability function are readily evaluated by properly combining the bounds of the interval mean-value and spectral moments of the response. Two numerical examples are provided to demonstrate the accuracy of the proposed procedure and its usefulness in view of decision-making in engineering practice.

Efficacy, safety, and tolerability of long-term lipoprotein apheresis in patients with LDL- or Lp(a) hyperlipoproteinemia: Findings gathered from more than 36,000 treatments at one center in Germany

LDL cholesterol (LDL-C) and lipoprotein(a) (Lp(a)) are main risk factors for cardiovascular disease (CVD).Efficacy, safety, and tolerability of lipoprotein apheresis (LA) were investigated in 36,745 LA treatments of 118 patients with CVD in a retrospective, monocentric study. Indications were severe hypercholesterolemia (n = 83) or isolated Lp(a) hyperlipoproteinemia (n = 35). Average age of patients at start of LA treatment was 58.1 years for males and 62.5 years for females. Medium interval between the first cardiovascular event and LA treatment was 6.4 ± 5.6 years and the average LA treatment period was 6.8 ± 4.9 years. On average treatments were performed once a week, via peripheral venous access in 79.3% of non-hemodialysis patients.In patients with hypercholesterolemia initial pre-LA LDL-C was lowered from 176.4 ± 67.0 mg/dL by 66.7 ± 10.8% per session, achieving a long-term interval mean value of 119.8 ± 34.7 mg/dL, i.e. reduction by 32.1 ± 19.6% (p < 0.0001). In patients with isolated elevated Lp(a) initial pre-LA Lp(a) was lowered from 127.2 ± 67.3 mg/dL by 66.8 ± 5.8% per session, achieving a long-term interval mean value of 60.0 ± 19.5 mg/dL, i.e. reduction by 52.8 ± 23.0% (p < 0.0001). After start of LA the average annual rate of major adverse coronary events (MACE) of all patients declined by 79.7% (p < 0.0001). Subgroup analysis showed decline by 73.7% (p < 0.0001) in patients with severe hypercholesterolemia, and by 90.4% (p < 0.0001) in patients with isolated elevated Lp(a). Adverse events (AE) occurred in 1.1% of treatments.LA treatment of patients with high risk for CVD due to LDL and/or Lp(a) hyperlipoproteinemia was effective, safe, and well tolerated. The number of cardiovascular events, at least during a six-year period, declined by 80%.

A supply chain application of fuzzy set theory to inventory control models – DRP system analysis

As competition abounds, the efficient solution on inventory control of a DRP’s (Distribution Requirement Planning) supply chain management is a vital success factor for companies in today’s business world. A stochastic program of market distribution and its deterministic equivalent control program is approximated by a multi-echelon lot-sizing model based on “risk inflated effective demands”. The DRP-decomposition of this approximate model, which can be used with allocation application of Fuzzy Set Theory, is then introduced. The aim of this paper is to find methods to address traditional DRP’s weaknesses and to improve the performances of DRP systems. In this paper, the field of continuous review model will be focused in, and a new method on the model with triangular fuzzy numbers (input data) will be presented. By using the method, the maximum of order quantity under a minimum of total cost can be obtained. In many previous research, authors take a precise number approximately as the representative of a fuzzy number. But the precise number can not reflect the property of fuzzy inventory control number fully. Therefore, in a numerical example of this paper, in addition to providing a transformation for reducing a fuzzy number into a closed interval by introducing the interval mean value concept proposed by Dubios and Prude, this fuzzy system can be transformed into a more precise diagnosis system for channel members in the supply chain distribution organization.

Zusammenhänge zwischen dem Wohlbefinden der Mutter und der Herzfrequenzvariabilität von Frühgeborenen

The relationship between mothers' well-being and the heart rate variability of their preterm babies was investigated. In order to study a possible influence of the mother's well-being on the calming quality of her voice and thereby on the heart rate variability of her preterm infant, maternal/paternal stress and competences as well as family functionality were assessed via respective questionnaires. (N = 30) Preterm babies at the postnatal age of approximately 4 weeks were acoustically stimulated with the voice of their own mother. Various heart rate variability measures (NN interval mean value, NN interval median, variance of NN intervals, standard deviation of NN intervals, pnn 6,25, RMSSD, SDSD and RSA) were recorded 15 minutes before, 15 minutes during and 15 minutes after the acoustic stimulation. Non-REM sleep sections of 2 minutes duration were matter of analyses. The correlations between the mothers' well-being and their babies' heart rate variability indicate a strong relationship. The correlations point out that a higher family functionality is associated with a higher heart rate variability of preterm babies. Contradictory to the expectations, higher burden and lower resources as well as lower competences of the mothers were associated with a higher heart rate variability of the preterm babies. Simultaneous real-time investigations of the mothers' and the babies' heart rate variability during a live mother-baby-interaction seems necessary to provide further explanations.

Evaluation of the optimal image reconstruction interval for coronary artery imaging using 64-slice computed tomography

Cardiac computed tomography (CT) has become an established complement in cardiac imaging. Thus, optimized image quality is diagnostically crucial. To prospectively evaluate whether, by using 64-slice CT, a specific reconstruction interval can be identified providing best image quality for all coronary artery segments and each individual coronary artery. 311 coronary segments of 14 men and seven women were analyzed using 64-slice CT. Data reconstruction was performed in 5% increments from 5-100% of the R-R interval. Four experienced observers independently evaluated image quality of the coronary arteries according to the AHA classification. A three-point ranking scale was applied: 1, very poor, no evaluation possible; 2, diagnostically sufficient quality; 3, highest image quality, no artifacts. The best reconstruction point for all segments was found to be 65% of the R-R interval (mean value 2.4+/-0.5; P<0.05). On a per-artery basis, best image quality was again achieved at 65% of the R-R interval: RCA 2.2+/-0.4, LCA 2.4+/-0.5, LM 2.5+/-0.2, LAD 2.3+/-0.4, LCX 2.3+/-0.5. By using 64-slice CT, the need for adjusting the reconstruction point to each coronary segment might be overcome. Best image quality was achieved with image reconstruction at 65% of the R-R interval for all coronary segments as well as each coronary artery.

Why there is a one-way crossability between D. melanogaster and D. simulans? An ontogenic explanation.

In the Drosophila melanogaster complex, females D. melanogaster mate relatively easily with males Drosophila simulans but the reciprocal cross is rare. The species sexual isolation is mainly based on chemical and acoustic signal exchanges between partners. The male side of this communication is investigated in this paper in order to understand the asymmetry. In D. melanogaster the acoustic signature is highly significant, and is synergistically reinforced by the chemical signal. In D. simulans the importance of the two signaling channels seems to be reversed. This could explain why D. simulans males produce less precise interpulse interval (IPI) mean value in the courtship song, which can readily overlap those of D. melanogaster. As the males of the two species use the same chemical key, D. simulans males could be recognized by D. melanogaster females as a conspecific.

An application of fuzzy set theory to inventory control models

A method for solving an inventory control problem, of which input data are described by triangular fuzzy numbers will be presented here. The continuous review model of the inventory control problem with fuzzy input data will be focused in, and a new solution method will be presented. For the reason that the result should be a fuzzy number because of fuzzy input data, and the certain number about order quantity is prefered in the real-world, it is necessary to transform the fuzzy result to crisp one. The interval mean value concept is used here to help to solve this problem. Under the condition of total cost minimum, the interval order quantity maximum can be obtained.