Solving Fuzzy Linear Programming Problems with Piecewise Linear Membership Function

In this paper, we concentrate on linear programming problems in which both the right-hand side and the technological coefficients are fuzzy numbers. We consider here only the case of fuzzy numbers with linear membership functions. The symmetric method of Bellman and Zadeh (1970) is used for a defuzzification of these problems. The crisp problems obtained after the defuzzification are non-linear and even non-convex in general. We propose here the modified subgradient method and method of feasible directions and uses for solving these problems see Bazaraa (1993). We also compare the new proposed methods with well known fuzzy decisive set method . Finally, we give illustrative examples and their numerical solutions

Neural network models for solving the maximum flow problem

In this paper, two new neural network models for solving the maximum flow problem are presented. The maximum flow problem in networks is formulated as a special type of linear programming problem and it is solved by appropriately defined neural networks. The nonlinear neural networks are able to generate optimal solution for maximum flow problem. We solve neural network models by one of the numerical method. Finally, some numerical examples are provided for the sake of illustration

Energy-Efficient Trajectory Planning for Skid-Steer Rovers

A skid-steer rover’s power consumption is highly dependent on the turning radius of its path. For example, a point turn consumes a lot of power compared to a straight-line motion. Thus, in path planning for this kind of rover, turning radius is a factor that should be considered explicitly. Based on the literature, there is a lack of analytical approach for finding energy-optimal paths for skid-steer rovers. This thesis addresses this problem for such rovers, specifically on obstacle-free hard ground. The equivalency theorem in this thesis indicates that, when using a popular power model for skid-steer rovers on hard ground, all minimum-energy solutions follow the same path irrespective of velocity constraints that may or may not be imposed. This non-intuitive result stems from the fact that with this model of the system the total energy is fully parametrized by the geometry of the path alone. It is shown that one can choose velocity constraints to enforce constant power consumption, thus transforming the energy-optimal problem to an equivalent time-optimal problem. Existing theory, built upon the basis of Pontryagin’s minimum principle to find the extremals for time-optimal trajectories for a rigid body, can then be used to solve the problem. Accordingly, the extremal paths are obtained for the energy-efficient path planning problem. As there is a finite number of extremals, they are enumerated to find the minimum-energy path for a particular example. Moreover, the analysis identifies that the turns in optimal paths (aside from a small number of special cases called whirls) are to be circular arcs of a particular turning radius, R′, equal to half of a skid-steer rover’s slip track. R′ is the turning radius at which the inner wheels of a skid-steer rover are not commanded to turn, and its description and the identification of its paramount importance in energy-optimal path planning are investigated. Experiments with a Husky UGV rover validate the energy-optimality of using R′ turns. Furthermore, a practical velocity constraint for skid-steer rovers is proposed that maintains constant forward velocity above R’ and constant angular velocity below it. Also, in separate but related work, it is shown that almost always equal “friction requirement” can be used to obtain optimal traction forces for a common and practical type of 4-wheel rover

A New Piecewise-Spectral Homotopy Analysis Method for Solving Chaotic Systems of Initial Value Problems

An accurate algorithm for solving initial value problems (IVPs) which are highly oscillatory is proposed. The proposed method is based on a novel technique of extending the standard spectral homotopy analysis method (SHAM) and adapting it to a sequence of multiple intervals. In this new application the method is referred to as the piecewise spectral homotopy analysis method (PSHAM). The applicability of the proposed method is examined on the differential equation system modeling HIV infection of CD4+ T cells and the Genesio-Tesi system which is known to be chaotic and highly oscillatory. Also, for the first time, we present here a convergence proof for SHAM. We treat in detail Legendre collocation and Chebyshev collocation. The method is compared to MATLAB’s ode45 inbuilt solver as a measure of accuracy and efficiency

Serum profiles of calcium, phosphorus, magnesium, vitamin D and parathyroid hormone in Caspian horses during different seasons

Minerals play an essential role in the normal vital process. Calcium, phosphorus and magnesium are the most abundant minerals. Vitamin D and parathyroid hormone play a key role in regulation of their homeostasis as well. The aim of this study was to evaluate calcium, phosphorus, magnesium, vitamin D and parathyroid hormone on 30 Caspian horses of Guilan Province (south of the Caspian Sea) in two different seasons. So that, 15 stallions and 15 mares were sampled at the age groups ≤ 3 years and > 3 years, respectively. Fasting blood samples were collected twice, in August and January 2015 from jugular vein of horses. Serum calcium, phosphorus and magnesium were measured by colorimetric methods, while 25(OH)D3 and parathyroid hormone were measured by ELISA. The calcium (11.50 vs. 14.25 mg dL-1 ), magnesium (2.13 vs. 3.72 mg dL-1 ) and vitamin D (1.66 vs. 2.48 ng mL-1 ) levels were lower in winter than in summer (P < 0.05). The Caspian horses had higher phosphorus (4.52 vs. 3.26 mg dL-1 ) in winter than in summer (P < 0.05). Effect of sex on the measured parameters was not significant. Effects of age on the calcium, magnesium, vitamin D and parathyroid hormone levels were not significant, but ≤ 3 year - old horses had higher phosphorus (4.63 vs. 3.15 mg dL-1 ) than > 3 year - old ones (P < 0.05). The vitamin D level of mares was higher (3.10 vs. 1.43 ng mL-1 ) in summer than in winter (P < 0.05). Effects of sex, season, age and their interactions on parathyroid hormone were not significant. In conclusion, calcium, phosphorus, magnesium and parathyroid hormone levels in Caspian horses were within their physiological range, but vitamin D was low without any signs of deficiency. The Caspian horses had lower calcium, magnesium and vitamin D levels in winter than in summer

Renal denervation in patients who do not respond to cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) reduces the morbidity and mortality in advanced heart failure (HF) in about two-thirds of the patients. Approximately one-third of the patients do not respond to CRT. The overactivity of sympathetic nervous system is associated with advanced HF and deteriorates the hemodynamic state. We tested the hypothesis that controlling sympathetic overactivity by renal denervation (RDN) could be beneficial in nonresponders for CRT. In our HeartF-RDN study (ClinalTrials.gov. NCT02638324), RDN could not reverse the progression of HF in subjects with New York Heart Association Classification (NYHA) III-IV stage symptoms.Peer reviewe

Pulmonary manifestations and the effectiveness of enzyme replacement therapy in Fabry Disease with the p. Arg227Ter (p.R227*) mutation

Background: Fabry disease (FD) is caused by a defect in α-galactosidase A gene (GLA) which leads to a progressive accumulation of neutral shingolipids, mainly globotriaosylceramide and its metabolites in several organs. Pulmonary manifestations of FD mimic chronic obstructive pulmonary disease and are disproportionate to smoking status. The effect of enzyme replacement therapy (ERT) on pulmonary function is inconclusive. We studied the effect of ERT on pulmonary function in FD with a mutation p. Arg227Ter (p.R227*) which is one of the most common mutations causing classical FD in Finland and worldwide.Methods: Patients were annually examined by multidisciplinary team. Based on the maximal pulmonary oxygen consumption at the baseline, either cardiopulmonary exercise test or combination of spirometry and 6-minute walking test were performed annually during 5-year follow-up.Results: Four males and eight females met the criteria for ERT and were included in this study. Three of 12 patients had obstruction by GOLD criterion before ERT, and one had a borderline obstruction. In 5 years, five patients were classified as obstructive, although the real change in FEV1/FVC was unchanged in the whole cohort. Only one patient was an active smoker.Conclusion: In nonsmokers, pulmonary manifestations in classical FD are mild and might be stabilized by ERT.</p

Evaluation of Sleep Quality and Its Socio-demographic Predictors in Three Trimesters of Pregnancy among Women Referring to Health Centers in Tabriz, Iran: A Cross-sectional Study

This study aimed to determine sleep quality and its socio-demographic predictors regarding three trimesters of pregnancy. This cross-sectional study was conducted on 605 pregnant women referred to health centers in Tabriz, Iran, using a two-stage cluster sampling method. Data were collected using socio-demographic characteristics questionnaire and the Pittsburgh Sleep Quality Index. The mean±SD of the total sleep quality scores were estimated at 5.22±2.52, 5.82±3.07, 8.60±3.03, and 6.56±3.24 in the first, second, and third trimester, and during the whole pregnancy, respectively. Moreover, the study results showed that 81 (40.1%), 105 (53.0%), 172 (83.9%), and 358 (59.2%) mothers experienced sleep disorder in the first, second, and third trimester, and during the whole pregnancy, respectively. According to the results of this study, sleep quality predictors may help health providers identify high-risk pregnant women in terms of sleep disorder to provide them with appropriate interventional programs

Cardiac Involvement in Fabry Disease: JACC Review Topic of the Week

Fabry disease (FD) is a rare X-linked inherited lysosomal storage disorder caused by deficient α-galactosidase A activity that leads to an accumulation of globotriasylceramide (Gb3) in affected tissues, including the heart. Cardiovascular involvement usually manifests as left ventricular hypertrophy, myocardial fibrosis, heart failure, and arrhythmias, which limit quality of life and represent the most common causes of death. Following the introduction of enzyme replacement therapy, early diagnosis and treatment have become essential to slow disease progression and prevent major cardiac complications. Recent advances in the understanding of FD pathophysiology suggest that in addition to Gb3 accumulation, other mechanisms contribute to the development of Fabry cardiomyopathy. Progress in imaging techniques have improved diagnosis and staging of FD-related cardiac disease, suggesting a central role for myocardial inflammation and setting the stage for further research. In addition, with the recent approval of oral chaperone therapy and new treatment developments, the FD-specific treatment landscape is rapidly evolving