An efficient optimization approach for designing machine learning models based on genetic algorithm

Machine learning (ML) methods have shown powerful performance in different application. Nonetheless, designing ML models remains a challenge and requires further research as most procedures adopt a trial and error strategy. In this study, we present a methodology to optimize the architecture and the feature configurations of ML models considering a supervised learning process. The proposed approach employs genetic algorithm (GA)-based integer-valued optimization for two ML models, namely deep neural networks (DNN) and adaptive neuro-fuzzy inference system (ANFIS). The selected variables in the DNN optimization problems are the number of hidden layers, their number of neurons and their activation function, while the type and the number of membership functions are the design variables in the ANFIS optimization problem. The mean squared error (MSE) between the predictions and the target outputs is minimized as the optimization fitness function. The proposed scheme is validated through a case study of computational material design. We apply the method to predict the fracture energy of polymer/nanoparticles composites (PNCs) with a database gathered from the literature. The optimized DNN model shows superior prediction accuracy compared to the classical one-hidden layer network. Also, it outperforms ANFIS with significantly lower number of generations in GA. The proposed method can be easily extended to optimize similar architecture properties of ML models in various complex systems

Accurate determination of elastic parameters for multi-component membranes

Heterogeneities in the cell membrane due to coexisting lipid phases have been conjectured to play a major functional role in cell signaling and membrane trafficking. Thereby the material properties of multiphase systems, such as the line tension and the bending moduli, are crucially involved in the kinetics and the asymptotic behavior of phase separation. In this Letter we present a combined analytical and experimental approach to determine the properties of phase-separated vesicle systems. First we develop an analytical model for the vesicle shape of weakly budded biphasic vesicles. Subsequently experimental data on vesicle shape and membrane fluctuations are taken and compared to the model. The combined approach allows for a reproducible and reliable determination of the physical parameters of complex vesicle systems. The parameters obtained set limits for the size and stability of nanodomains in the plasma membrane of living cells.Comment: (*) authors contributed equally, 6 pages, 3 figures, 1 table; added insets to figure

Enhancing the Mass Sensitivity of Graphene Nanoresonators Via Nonlinear Oscillations: The Effective Strain Mechanism

We perform classical molecular dynamics simulations to investigate the enhancement of the mass sensitivity and resonant frequency of graphene nanomechanical resonators that is achieved by driving them into the nonlinear oscillation regime. The mass sensitivity as measured by the resonant frequency shift is found to triple if the actuation energy is about 2.5 times the initial kinetic energy of the nanoresonator. The mechanism underlying the enhanced mass sensitivity is found to be the effective strain that is induced in the nanoresonator due to the nonlinear oscillations, where we obtain an analytic relationship between the induced effective strain and the actuation energy that is applied to the graphene nanoresonator. An important implication of this work is that there is no need for experimentalists to apply tensile strain to the resonators before actuation in order to enhance the mass sensitivity. Instead, enhanced mass sensitivity can be obtained by the far simpler technique of actuating nonlinear oscillations of an existing graphene nanoresonator.Comment: published versio

The bilingual native speaker competence: evidence from explicit and implicit language knowledge using elicited production, sentence-picture matching, and pupillometry

The present pilot study investigated potential effects of early and late child bilingualism in highly proficient adult bilinguals. It has been shown that some early second language (eL2) speakers stagnate when it comes to complex linguistic phenomena and that they display subtle difficulties in adulthood. Therefore, we have chosen the complex structure of double object constructions. We investigate the long-term achievement in a combined-method approach using elicited production, explicit comprehension by sentence-picture matching and a measure of implicit linguistic knowledge, namely pupillometry. This eye tracking method is suitable for measuring implicit reactions of the pupils to unexpected or ungrammatical stimuli. For production, ditransitive structures were elicited by means of a game. For comprehension, a sentence-picture matching task was conducted. Two pictures were shown on a monitor that were equal with respect to the involved objects, but the thematic roles of direct and indirect objects were interchanged. Items were controlled for length, gender, animacy, semantic likelihood and word order. Reaction times and accuracy scores were analyzed. To this end, N = 18 bilingual adult speakers of German (+ another language, mean age: 26.5) with different ages of onset participated in this study and were compared to N = 26 monolingual German adult speakers (mean age 23.9). All participants had a proficiency of German above 89% correct in placement and cloze tests. Results show fully comparable productive and comprehensive competencies in monolinguals and bilinguals including the reaction times in the sentence-picture matching task and a word order effect on the reaction times in both groups. In the pupillometry task, we found monolinguals and bilinguals to be sensitive to differing conditions with respect to grammatical and ungrammatical utterances. However, we find between group differences in pupil dilations in that bilinguals react differently to strong grammatical violations than monolinguals. These results are discussed with respect to the term of native speaker competence and the variation within both groups

Quality Assessment of MORL Algorithms: A Utility-Based Approach

Sequential decision-making problems with multiple objectives occur often in practice. In such settings, the utility of a policy depends on how the user values different trade-offs between the objectives. Such valuations can be expressed by a so-called scalarisation function. However, the exact scalarisation function can be unknown when the agents should learn or plan. Therefore, instead of a single solution, the agents aim to produce a solution set that contains an optimal solution for all possible scalarisations. Because it is often not possible to produce an exact solution set, many algorithms have been proposed that produce approximate solution sets instead. We argue that when comparing these algorithms we should do so on the basis of user utility, and on a wide range of problems. In practice however, comparison of the quality of these algorithms have typically been done with only a few limited benchmarks and metrics that do not directly express the utility for the user. In this paper, we propose two metrics that express either the expected utility, or the maximal utility loss with respect to the optimal solution set. Furthermore, we propose a generalised benchmark in order to compare algorithms more reliably

Relationship Between Body Composition, Diet, and Food Addiction in Young Adult Females

Addictive behavior in relation to food is often a consistent variable with obesity and aberrant eating. However, body composition alone is not a strong indicator of food addiction, rather is associated with other factors such as quality of diet, making the compulsive behavior difficult to diagnose. Eating disorders are widespread amongst young adult females and warrant further investigation. PURPOSE: To identify various factors that may attribute to food addiction symptoms in young adult females. METHODS: The study consisted of twelve physically healthy females (age = 20.8 ± 1.6 yr and BMI = 21.9 ± 1.6 kg/m2). Dual-Energy X-ray absorptiometry was used to evaluate body composition. A 3-day dietary log was collected (2 weekdays and 1 weekend day) and analyzed using the Food Processor Software. Symptoms of food addiction were evaluated using the Yale Food Addiction Scale 2.0. Six participants displaying food addiction symptoms (FAS) were matched (BMI, age, fat-free mass, and body fat %) and compared with 6 complementary females without food addiction symptoms (WFAS). Data were analyzed via a Pearson correlation analysis and a one-way ANOVA (p \u3c 0.05). RESULTS: There was no statistically significant difference found in intake of energy, carbohydrates, proteins, fats, and saturated fats based on total calories. Although not statistically significant, the mean omega-3 intake of FAS (.88 ± .58g) was lower than that of WFAS (1.07 ± 1.03g), and omega-6 was 6.2 ± 4.9g for FAS and 4.2 ± 2.5g for WFAS, respectively. The macronutrient breakdown for FAS was as follows: total intake – 1572 ± 69 kcal/day, carbohydrates – 706 ± 132 kcal/day, proteins – 308 ± 52 kcal/day, and fats – 557 ± 83 kcal/day. The macronutrient breakdown for WFAS was 1923 ± 527 kcal/day (total intake), 875 ± 208 kcal/day (carbohydrates), 346 ± 123 kcal/day (proteins), and 701 ± 248 kcal/day (fats). WFAS consumed 208 ± 72 kcal/day of saturated fats, while FAS consumed 25% more saturated fats (265 ± 35 kcal/day). Waist to hip ratio between FAS and WFAS was significantly different (p = .032), where FAS = 0.75 ± 0.03 and WFAS = 0.70 ± 0.03. CONCLUSION: Though there was no significant statistical difference in total caloric intake between the food addictive and non-addictive groups, there was a noticeable trend that the food addictive group consumed fewer calories but had a higher waist to hip ratio. This trend suggests that the quality of diet, rather than total intake, may be related to a higher waist to hip ratio. Additionally, the food addictive group had a lower total fat intake and consumed more saturated fats than the non-addictive group. Saturated fats are conventional in most heavily processed foods. Though the food addictive group is consuming fewer total calories, there is a larger portion of their diet made up of saturated fats suggesting an imbalance in diet quality associated with food addiction. Future research analyzing the type and quality of food consumed in larger sample size is encouraged

Obesidad infantil y parámetros de composición corporal en niños de extremadura (españa).

Introducción En las sociedades desarrolladas la obesidad es uno de los trastornos nutricionales más frecuente en la infancia y la adolescencia (Serra Majem, 2003) y el quinto factor principal de riesgo de defunción en el mundo (Fernández-Bergés, 2012. Estudios previos establecen que 2 de cada 10 niños/as extremeños padecen obesidad o sobrepeso (Torres, 2008). El objetivo del estudio es describir la prevalencia de la obesidad en escolares extremeños y conocer la influencia de la obesidad sobre factores de parámetros de composición corporal. Métodos 242 niños/as (9 a 12 años) de centros de primaria de la Comunidad Autónoma de Extremadura fueron evaluados. Tras informar y recibir el consentimiento informado de los tutores legales de los sujetos, se llevaron a cabo mediciones individuales de parámetros antropométricos : peso, talla, IMC, masa grasa, masa libre de grasa, % grasa y peso óseo, índice cintura-cadera. Se llevó a cabo un análisis descriptivo para conocer el porcentaje de obesidad entre los escolares y un ANOVA de un factor con un test post hoc para comparar los resultados con los tres niveles del factor de estudio (normopeso, sobrepeso y obesidad). Resultados El 9,9% de los niños/as extremeños evaluados eran obesos, siendo este porcentaje mayor en el caso de los niños (11,2% frente a 8,54% de las niñas). Existen diferencias significativas (p> 0.05) en cuanto al nivel de composición corporal en las variables IMC, ICC, masa grasa y % masa grasa. Conclusiones 18% escolares extremeños presenta sobrepeso u obesidad, valor que se ha mantenido constante en los últimos años. Los niños/as con sobrepeso y obesidad presentan mayores niveles de IMC, ICC y niveles de grasa corporal

An Evaluation Of Static and Dynamic Yoga Training Programs

While traditional yoga programs focus on static stretching and core stability, Essentrics yoga relies more heavily on full-body stretch and strengthening regiments coupled with dynamic movements such as ceiling reaches, side-to-side bends, lunges, and side leg lifts. Through the incorporation of more dynamic movements, Essentrics yoga is thought to elicit greater improvements in overall body composition, flexibility, and balance. PURPOSE: To examine the benefits of a 6-weeks long Essentrics (dynamic) program compared to standard (static) Yoga on body composition, flexibility, and balance. METHODS: Thirty-one participants (24 females and 7 males, age = 20.4 ± 0.2yrs, and BMI = 22.58 ± 0.55kg/m2) were assigned to two groups – a standard Yoga (YOG, n = 20) and an Essentrics (ESS, n = 11) group. For 6 weeks, both groups attended a 45–50-minute class, 3 times per week. Body composition (dual-energy x-ray absorptiometry), flexibility (sit-and-reach), balance (lower extremity Y-balance), as well anthropometric measurements were assessed at the beginning and end of the 6-week program. Measurements of the balance test included 3 reaches and their combined values [anterior (ANT), posteromedial (PM), posterolateral (PL), and composite reach distance (CRD)]. All reaches were averaged for the right and left sides and then normalized to leg length. Data were analyzed using an ANOVA with repeated measures (p \u3c 0.05), and a post-hoc test was performed if any significant main or interaction effects were found. RESULTS: Interestingly, the total body fat percentage was significantly reduced only in the YOG group (24.44 ± 6.73 to 23.51 ± 6.32%, p=.002). There were no significant group differences between YOG and ESS in balance and flexibility. However, balance was improved after the 6-week workout programs; PM (87.13 ± 11.64cm to 92.25 ± 9.91cm, p=.001), PL (82.88 ± 11.28 to 88.62 ± 9.62cm, p=.002), CRD (225.96 ± 27.17 to 238.26 ± 22.98cm, p=.001), normalized PM (98.31 ± 11.68 to 104.27 ± 11.14%, p=.001), normalized PL (93.60 ± 11.98 to 100.15 ± 10.70%, p=.001), and normalized CRD (255.12 ± 27.89 to 269.21 ± 25.07%, p=.001). Additionally, flexibility was improved from 51.42 ± 8.24 to 53.38 ± 7.04cm (p=.010) after the 6-week workout programs, while total body fat percentage was significantly reduced only in the YOG group (24.44 ± 6.73 to 23.51 ± 6.32%, p=.002). CONCLUSION: Whether an individual prefers a static or dynamic yoga program, both show improvements in flexibility and balance; however, neither program had a significant benefit over the other