Using Machine Learning to Greatly Accelerate Path Integral Ab Initio Molecular Dynamics

Ab initio molecular dynamics (AIMD) has become one of the most popular and robust approaches for modeling complicated chemical, liquid, and material systems. However, the formidable computational cost often limits its widespread application in simulations of the largest scale systems. The situation becomes even more severe in cases where the hydrogen nuclei may be better described as quantized particles using a path integral representation. Here, we present a computational approach that combines machine learning with recent advances in path integral contraction schemes, and we achieve a two-orders-of-magnitude acceleration over direct path integral AIMD simulation while at the same time maintaining its accuracy.

A Study on the Estimation of Source Bearing in an ASA Wedge: Diminishing the Estimation Error Caused by Horizontal Refraction

The performance of warping transformation in diminishing the error in underwater source-bearing estimation, caused by horizontal refraction effects (also named 3D effects), is studied. First, the capability of warping transformation for separating the normal modes, as well as their direct and horizontally refracted paths, in a standard Acoustical Society of America (ASA) wedge is demonstrated. Second, the error values for source bearing estimation in three different manners, i.e., using the full signal, using its component corresponding to the first mode, and using the component of the latter corresponding only to the direct path are compared for the same wedge case. The results show that the estimation error can be significantly reduced by beamforming, with only the first mode, or using the direct path of the first mode in cases where there exists a horizontally refracted path of the first mode.

THE EXISTENTIAL NATURE OF THE HIKMETS OF AHMED YASSAWI

This article analyzes existential concepts in the work of Ahmet Yassawi “Diwani hikmet”, which forms the Sufi direction of the deeply rooted Turkic civilization, using comparative research methods. In this context, the article collected and investigated the following metaphysical problems, such as the unity and struggle of time and being, disinterested attachment to the Creator, as well as the phenomenon of life and death. The content of the Hikmet is an existential representation of a religious preaching orientation, filled with the principles of a nomadic civilization developed in the Kazakh steppe. Although the main goal of the Hikmet is religious, there are often such existentials as the existence of the Creator and the problems of human existence, life and death, morality, justice, responsibility, conscience. The main position of the Hikmets is to point out a direct path to the Islamic world and suggest ways to form a “True Muslim”. The concepts of the book of wisdom are a way of revealing transcendental contradictions for those who are in an existential crisis. For those who cannot understand the meaning of life and are in existential stagnation, we decided to use the hikmet of Ahmet Yassawi to explain the meaning of real life.

Social Networks and Internet Emotional Relationships on Mental Health and Quality of Life in Students: Structural Equation Modelling

Background: Social networks and relationships create a sense of belonging and social identity and therefore have a major effect on mental health and quality of life, especially in young people. The present study was conducted to determine the predictor role of social networks and Internet emotional relationships on mental health and quality of life in students. Methods: The present cross-sectional study was conducted in 2021 on 350 students at Alborz University of Medical Sciences selected by convenience sampling. Data were collected using five questionnaires: Socioeconomic Status, Social Networks, Internet Emotional Relationships Mental Health, Quality of Life and a checklist of demographic details. Data were analyzed in SPSS-25, PLS-3, and Lisrel-8.8.Results: According to the path analysis results, mental health had the most significant positive causal relationship with Internet emotional relationships in the direct path (B=0.22) and the most negative relationship with socioeconomic status (B=-0.09). Mental health was assessed using DASS-21, in which higher scores mean higher mental disorders. Quality of life had the highest negative causal relationship with the DASS-21 score in the direct path (B=-0.26) and the highest positive relationship with socioeconomic status in the indirect path (B=0.023). The mean duration of using social networks (B=-0.067) and Internet emotional relationships (B=-0.089) had the highest negative relationship with quality of life.Conclusion: The use of the Internet and virtual networks, Internet emotional relationships and unfavourable socioeconomic status were associated with mental disorders and reduced quality of life in the students. Since students are the future of any country, it is necessary for policymakers to further address this group and their concerns.

OBSERVER’S TRAJECTORY TRACKING OBJECT BYPASSING OBSTACLE ON THE SHORTEST CURVE

Motion of some object is considered. The object t moves from the initial point t∗ to the final one t ∗ . But since absent of the direct path, he should bypass an obstacle a connected bodily set G. It is supposed that t moves by the most short trajectory T = Tt , and the trajectory T is a convex curve. The observer’s f task is to find the trajectory Tf that provides tracking the object on the most part of the object’s motion and, if possible, the lesser object’s stealth of motion along the trajectory T . The latency is defined by the distance that the observer must pass to see the object in the field of vision. The object and observer start at the same initial instant, and their velocities are equal. In the paper, examples of the trajectories Tf in R 2 are presented, on which the observer can see the object’s trajectory T ; also, the value of the object’s latency is shown for the invisible parts of the trajectory T . The variant of Tf in R 3 is shown.

Using Machine Learning to Greatly Accelerate Path Integral Ab Initio Molecular Dynamics

Ab initio molecular dynamics (AIMD) has become one of the most popular and robust approaches for modeling complicated chemical, liquid, and material systems. However, the formidable computational cost often limits its widespread application in simulations of the largest scale systems. The situation becomes even more severe in cases where the hydrogen nuclei may be better described as quantized particles using a path integral representation. Here, we present a computational approach that combines machine learning with recent advances in path integral contraction schemes, and we achieve a two-order-of-magnitude acceleration over direct path integral AIMD simulation while at the same time maintaining its accuracy.

Interrelationships among whole-body skeletal muscle mass, masseter muscle mass, oral function, and dentition status in older Japanese adults

Background Generalized loss of skeletal muscle mass (SMM) may modulate or otherwise affect the loss of masseter muscle mass and be responsible for low masseter muscle performance and strength (i.e., low oral function). Moreover, dentition status can affect oral function independent of the muscle state. This cross-sectional study aimed to simultaneously investigate the relationships among whole-body SMM, masseter muscle mass, oral function (masseter muscle performance and strength), and dentition status in 1349 Japanese adults (mean age = 73.6 years). Methods We determined the estimated masseter muscle mass (e-MMM) based on morphological measurements of the masseter muscle. Masseter muscle performance was assessed via masticatory performance evaluation scores using gum, and strength was assessed as the maximal occlusal force. Dentition status was assessed as the number of functional teeth. SMM was measured by bioelectrical impedance analysis. Structural equation modeling stratified by sex was employed to investigate associations among SMM, e-MMM, gum score, occlusal force, and number of functional teeth. Results The direct path from SMM to e-MMM was statistically significant, as was the direct path from e-MMM to oral function (gum score and maximum occlusal force) for both sexes. We additionally confirmed that SMM indirectly affected gum score and maximum occlusal force via e-MMM (men; standardized coefficient [95% CI] = 3.64 [1.31 to 5.96] for maximum occlusal force and 0.01 [0.01 to 0.02] for gum score, women; 2.01 [0.38 to 3.81] for maximum occlusal force and 0.01 [0.002 to 0.01] for gum score). The number of functional teeth had direct effects on e-MMM, gum score, and maximum occlusal force. Conclusions Low SMM was significantly indirectly associated with poor oral function through a low masseter muscle mass, and dentition status was independently associated with oral function.

Predictors of the Relationship Between the Duration of Cancer and Care Time with the Supportive Care Needs of Patients and the Quality of Life of Their Caregivers: A Path Analysis

Background Breast cancer patients face various material, and the mutual impact of patients and caregivers on each other show the need for further supportive care from the community and family. This study aimed to identify the predictors of the direct and indirect relationships of the duration of cancer and care time with the supportive needs of the patients and the quality of life of their family caregivers.Methods This descriptive-analytical study was carried out on 150 patients and their caregivers in Iran. Data were collected using the Supportive Care Needs Survey-short form (SCNS-SF34), the Caregiver Quality of Life Index-Cancer (CQOLC) scale, and a socio-demographic checklist and were then analyzed in SPSS-24 and Lisrel-8.8 software using descriptive-analytical statistics and path analysis.Results The mean age of the patients and caregivers was 45.76±10.44 and 43.46±9.5, respectively. Based on the test results, the duration of cancer was positively correlated with the total score of supportive needs in both paths (B=0.799). The patients’ sexuality needs had the highest negative correlation with their duration of cancer in the direct path (B=-0.87) and psychological needs the highest negative correlation in the indirect path (B=-0.32). The care time (in hours) had the highest positive correlation with the total score of supportive needs (B=15.6) in both the direct and indirect paths, and the highest positive correlation with physical needs in the direct path (B=10.65). The caregivers’ quality of life had a negative and direct relationship with the duration of cancer (B=-0.27) and there was a positive and direct relationship between care time and the caregivers’ quality of life (B=3.09). Conclusions Duration of cancer and care time had the highest positive correlation with the patients’ supportive needs, and the caregivers’ quality of life had a negative correlation with the duration of cancer and a positive correlation with care time. It is therefore vital to emphasize the design and implementation of supportive care programs for breast cancer patients and their family caregivers.