124 research outputs found
METAHEURISTICS FOR HUB LOCATION MODELS
In this research, we propose metaheuristics for solving two p-hub median problems.. The first p-hub median problem, which is NP-hard, is the uncapacitated single p-hub median problem (USApHMP). In this problem, metaheuristics such as genetic algorithms, simulated annealing and tabu search, are applied in different types of representations. Caching is also applied to speed up computational time of the algorithms. The results clearly demonstrate that tabu search with a permutation solution representation, augmented with caching is the highest performing method, both in terms of solution quality and computational time among these algorithms for the USApHMP. We also investigate the performance of hybrid metaheuristics, formed by path-relinking augmentation of the three base algorithms (genetic algorithms, simulated annealing and tabu search). The results indicate that hybridrization with path-relinking improvees the performance of base algorithms except tabu search since a good base metaheuristic does not require path-relinking. For the second p-hub median problem, the NP-hard uncapacitated multiple p-hub median problem (UMApHMP), we proposed Multiple TS. We identify multiple nodes using the convex hull and methods derived from the tabu search for the USApMHP. We find optimal allocations using the Single Reallocation Exchange procedure, developed for the USApHMP. The results show that implementing tabu search with a geometric interpretation allows nearly all optimal solutions to be found
ANALYTICAL SOLUTION FOR THE TEMPERATURE DISTRIBUTION IN CROSS-FLOW PLATE HEAT EXCHANGER CHANNELS OF ISOSCELES TRIANGULAR GEOMETRY
This paper presents the analytical solutions for the temperature distribution in cross-flow plate heat exchanger under uniform temperature boundary conditions. The heat transfer channel is in a form of an isosceles triangular geometry. The governing equations are based on the conservation of energy principle. The mathematical models, for both unmixed fluid, are solved by Laplace Transform leads to the developed analytical solution that is in the form of modified Bessel function of the first kind and zero order
Depression in adults asthmatic patients: pathophysiology, impacts, related factors, and nursing care
Both severe and non severe asthmatic attack have influenced on the patient in all perspectives consists of physical, psychological, social and economic perspectives. Ineffective control of the asthma can cause depression that leads to inconsistent to the treatment. In the depressed asthmatic patients, the daily activities are limited and the pulmonary function is declined due to inconsistent to the treatment. In order to effectively control and treat the asthma ,tie patients, the depression should be identified and treated
Emergency contraception in adolescences
Unintended pregnancy in adolescences is an important public health problem in bothdeveloping and developed country, and causes various adverse maternal and fetal outcomes which results in increased mortality and morbidity of the mother and the newborn. The emergency contraception is effective in preventing unintended pregnancy. To prevent unintended pregnancy effectively, the adolescence should know and use the emergency contraception properly. The method of usage, effectiveness, mechanism, side effect, and factors of emergency contraceptive methods were described in this presentation
Attitude, awareness and characteristics of emergency contraceptive pill usage among adolescents
The emergency contraceptive pill (ECP) is effective in preventing unintended pregnancy. This study was a descriptive research. The aim of this study was to investigate the characteristics of ECP usage in female adolescence, and compare the attitudes and awareness of using ECP. The subjects were junior and senior high school students living in Bangkok, aged between 13-19 years. They were divided into 2 groups, 85 subjects per group. The research tool was a questionnaire asking about attitude, awareness and the characteristics of ECP used. The data was analyzed by descriptive statistics and t-test. The results found the group of junior and senior high school students knew the ECP for preventing unintended pregnancy after unprotected sexual intercourse (98.8% vs. 97.6%, respectively). However, the adolescents were uncertain when the ECP should be used efficiently (58.8% vs. 41.2%, respectively). Most of these adolescents have ever received information about ECP from peer (23.5% vs. 22.3%, respectively) and most gave a reason to use ECP that it might be the most effective way to prevent pregnancy (20.0% vs. 23.5%). The senior high school students had lower mean scores for attitudes about using ECP than the junior high school students (34.6 vs. 36.2, p = 0.121, respectively). However, they had statistically significant higher scores for awareness about ECP than the junior high school students (7.2 vs. 5.5, p = 0.000 respectively). The overall attitudes about using ECP were in positive. Most of this group have everheard or been aware of the ECP (88.2% and 94.1%, respectively). Some in both groups had ever heard about or understood the mechanisms of emergency contraceptive pills (30.6% and 51.8%, respectively). Adolescents should be use the ECP for prevent unintended pregnancy. The health care providers shouldprovide information of mechanism, method of usage, side effect, and effectiveness of ECP to adolescents
Optimization for Biodiesel Production by Transesterification with Electric Fields
The objective of this research is to study optimization for biodiesel production from transesterification with electric fields. The catalyst in this reaction is potassium hydroxide (KOH) at 1% weight (wt). The molar ratio is 6:1. Two factors at three levels are considered using the response surface method. The first factor, the intensity of the electric field, is set at 85 volts/centimeter (V/cm), 170 V/cm, and 255 V/cm. The second factor, the retention time of the electric fields, is set at 2 minutes (min), 6 min, and 10 min. In the experiments, the best yields are produced from an electric fields intensity of 85 V/cm, with the electric field’s retention time of 2 min. The calculated and experimental results are 98.26% and 98.41%, respectively
Localized radial roll patterns in higher space dimensions
Localized roll patterns are structures that exhibit a spatially periodic profile in their center. When following such patterns in a system parameter in one space dimension, the length of the spatial interval over which these patterns resemble a periodic profile stays either bounded, in which case branches form closed bounded curves (“isolas”), or the length increases to infinity so that branches are unbounded in function space (“snaking”). In two space dimensions, numerical computations show that branches of localized rolls exhibit a more complicated structure in which both isolas and snaking occur. In this paper, we analyse the structure of branches of localized radial roll solutions in dimension 1+ε, with 0 < ε 1, through a perturbation analysis. Our analysis sheds light on some of the features visible in the planar case.http://math.bu.edu/people/mabeck/Bramburgeretal18.pdfFirst author draf
Development of Augmented Reality Application for Exercise to Promote Health among Elderly
This research aimed to: (1) develop and find the effectiveness of augmented reality application for exercise to promote health among elderly, (2) compare physical fitness in terms of flexibility of the elderly before and after exercising by augmented reality application for exercise to promote health among elderly, and (3) study elderly satisfaction towards the use of augmented reality application for exercise. The samples were 30 elderly in Bueng Namrak, Thailand. The samples were selected through a purposive sampling technique. The instruments were augmented reality application for exercise to promote health among elderly, physical fitness test in terms of flexibility, and satisfaction form. The results showed that learning and using augmented reality application for exercise to promote health among elderly was effective according to KW1 80.80 at KW1 80/83.33. The physical fitness in terms of flexibility after using the application was higher than before using the application. The physical fitness in terms of flexibility before using the application was 5.91 in average, with standard deviation of 6.76, whereas the average after using the application was 6.15, with the standard deviation of 6.53. The t-test value after using the application was 2.80 at a statistically significant level of.05. The satisfaction of the elderly towards the use of augmented reality application for exercise to promote health among elderly was 4.64 in average, which was at the highest level
Molecular dynamics simulation study of the concentration dependence of the self-diffusivity of methanol in NaX zeolite
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