Visualizing and Slicing Topological Surfaces in Four Dimensions

2021 ◽  
Author(s):  
Huan Liu ◽  
Hui Zhang
Keyword(s):  
Longitudinal Axis ◽  
Time Lapse ◽  
Usability Study ◽  
Cross Sectional ◽  
Triangle Meshes ◽  
New Approach ◽  
Four Dimensions ◽  
Topological Features ◽  
Internal Structures ◽  
3D Movie

Smooth topological surfaces embedded in 4D create complex internal structures in their projected 3D figures. Often these 3D figures twist, turn, and fold back on themselves, leaving important properties behind the surface sheets. Triangle meshes are not well suited for illustrating such internal structures and their topological features. In this paper, we propose a new approach to visualize these internal structures by slicing the 4D surfaces in our dimensions and revealing the underlying 4D structures using their cross-sectional diagrams. We think of a 4D-embedded surface as a collection of 3D curves stacked and evolved in time, very much like a 3D movie in a time-elapse form; and our new approach is to translate a surface in 4-space into such a movie — a sequence of time-lapse frames where successive terms in the sequence differ at most by a critical change. The visualization interface presented in this paper allows us to interactively define the longitudinal axis, and the automatic algorithms can partition the 4D surface into parallel slices and expose its internal structure by generating a time-lapse movie consisting of topologically meaningful cross-sectional diagrams from the representative slices. We have extracted movies from a range of known 4D mathematical surfaces with our approach. The results of the usability study show that the proposed slicing interface allows a mathematically true user experience with surfaces in four dimensions.

Validation of mathematical model of electrothermal calculation of DC catenary on the basis of scale model

2018 ◽  
Vol 77 (4) ◽  
pp. 222-229 ◽  
Author(s):  
A. V. Paranin ◽  
A. B. Batrashov
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Scale Model ◽  
Contact Network ◽  
Scaled Model ◽  
Cross Sectional ◽  
Current Collection ◽  
Topological Features ◽  
Study Results ◽  
Real Physical Process

The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.

scholarly journals Preferences for Updates on General Research Results: A Survey of Participants in Genomic Research from Two Institutions

2021 ◽  
Vol 11 (5) ◽  
pp. 399
Author(s):  
Casey Overby Taylor ◽  
Natalie Flaks Manov ◽  
Katherine D. Crew ◽  
Chunhua Weng ◽  
John J. Connolly ◽  
...  
Keyword(s):  
Research Result ◽  
Hierarchical Cluster ◽  
Genomic Research ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Four Dimensions ◽  
Research Participants ◽  
Research Activities ◽  
Study Results ◽  
Set Up

There is a need for multimodal strategies to keep research participants informed about study results. Our aim was to characterize preferences of genomic research participants from two institutions along four dimensions of general research result updates: content, timing, mechanism, and frequency. Methods: We conducted a web-based cross-sectional survey that was administered from 25 June 2018 to 5 December 2018. Results: 397 participants completed the survey, most of whom (96%) expressed a desire to receive research updates. Preferences with high endorsement included: update content (brief descriptions of major findings, descriptions of purpose and goals, and educational material); update timing (when the research is completed, when findings are reviewed, when findings are published, and when the study status changes); update mechanism (email with updates, and email newsletter); and update frequency (every three months). Hierarchical cluster analyses based on the four update preferences identified four profiles of participants with similar preference patterns. Very few participants in the largest profile were comfortable with budgeting less money for research activities so that researchers have money to set up services to send research result updates to study participants. Conclusion: Future studies may benefit from exploring preferences for research result updates, as we have in our study. In addition, this work provides evidence of a need for funders to incentivize researchers to communicate results to participants.

Digital skills and complex thinking in engineering students of a particular university in Lima in times of pandemic

2021 ◽  
Vol 7 (3C) ◽  
pp. 155-165
Author(s):  
Luis Alex Valenzuela Fernández ◽  
Violeta Cadenillas Albornoz ◽  
Blanca Soledad Zavala Alfaro ◽  
Jean Paul Suazo Zárate ◽  
Cesar Ulloa-Silvestre
Keyword(s):  
Digital Literacy ◽  
Engineering Students ◽  
Private University ◽  
Communication Management ◽  
Management Communication ◽  
Cross Sectional ◽  
Four Dimensions ◽  
Complex Thinking ◽  
Digital Skills ◽  
Medium Level

This article focuses on the relationship of digital skills and complex thinking in engineering students from a private university in Lima, Peru. A non-experimental, descriptive, correlational, cross-sectional quantitative study was carried out. The sample consisted of 175 engineering students who were administered the questionnaires developed in Google Forms for digital skills and the complex XXI scale to measure complex thinking with reliability values of .965 and .941 respectively for the alpha of Cronbach. The descriptive results showed that 48% of the respondents were found at the medium level of digital skills and that in the case of complex thinking there was a significant tie between the medium and high levels (approximately 41%). It was concluded that there was a strong and positive correlation between digital skills and complex thinking (Pearson's correlation = .759). In addition, four dimensions of digital literacy were evaluated (information management, communication management, wearable technology management and organizational aspects) which showed a positive and moderate relationship with complex thinking.

scholarly journals A Study on Emotional Intelligence among School Going Adolescents in Kolkata

2021 ◽  
pp. 47-58
Author(s):  
Bikash Chandra Ghorai ◽  
Samayita Kundu ◽  
Sunil Santra
Keyword(s):  
Emotional Intelligence ◽  
Sampling Technique ◽  
Cross Sectional Survey ◽  
School Students ◽  
Cross Sectional ◽  
Data Set ◽  
Intelligence Scale ◽  
Four Dimensions ◽  
Significant Difference ◽  
Understanding Emotions

The aim of the present study is to determine the level of emotional intelligence of school going adolescents; and to compare the emotional intelligence and its four dimensions/sub-factors i.e., understanding emotions, understanding motivation, empathy and handling relation of school going adolescents with respect to their gender, grade and board pattern of education. The present study was carried out on 288 higher secondary school students selected as sample from six schools of three different boards of education (viz. two WBCHSE, two CBSE and two ICSE) of Kolkata district in West Bengal using convenient sampling technique. This research is cross-sectional survey type study. The measuring tool in this research originally was of two-point emotional intelligence scale entitled as ‘Emotional Intelligence Scale (ESI – SANS) of Dr. A. K. Singh and Dr. S. Narain [1] which was translated in Bengali version by B. C. Ghorai and L. L. Mohakud [2]. After the initial exploratory analysis of the data, different statistical (descriptive and inferential) techniques are used to analyze the data set via SPSS 20. Results of the study revealed that there is no statistically significant difference in emotional intelligence and it’s sub-factors of school going adolescent with respect to their gender grade and board pattern of education. The findings provide a further need on how to more improve upon the emotional intelligence of school going adolescent. Implications and recommendations for developing emotional intelligence school going adolescent are discussed.

scholarly journals Diseño y validación de un cuestionario sobre las concepciones y percepción de los estudiantes sobre la evaluación en Educación Física (Design and validation of a questionnaire about the conceptions and perception of the students about the assessment in P

Retos ◽  
2020 ◽  
pp. 317-325
Author(s):  
Enoc Valentín González Palacio ◽  
Beatriz Elena Chaverra Fernández ◽  
Sirley Andrea Bustamante Castaño ◽  
Carlos Andrés Toro Suaza
Keyword(s):  
High School Students ◽  
Physical Education ◽  
Physical Education Teachers ◽  
Physical Education Class ◽  
Information Process ◽  
School Students ◽  
Cross Sectional ◽  
Four Dimensions ◽  
Education Class ◽  
Experimental Type

 El propósito de este estudio fue diseñar y validar un cuestionario sobre las concepciones y percepción de los estudiantes de educación secundaria sobre la evaluación en la clase de Educación Física (EF). Este estudio fue de corte transversal, de tipo no experimental descriptivo, el proceso de validación del cuestionario contó con la participación de ocho expertos licenciados en educación física (seis doctores y dos magister en el área), quienes determinaron el número de preguntas establecidas para el cuestionario. La aplicación del instrumento se hizo con 355 estudiantes del área metropolitana del Valle de Aburrá (Antioquia-Colombia). La muestra fue no probabilística, el tratamiento de la información se realizó mediante el software SPSS v23. El cuestionario está estructurado en cuatro dimensiones: concepciones, actores, instrumentos-momentos y contenidos. La conclusión principal del estudio derivado del proceso de la validez del contenido y el análisis de fiabilidad, demuestra que el instrumento es acertado y adecuado, convirtiéndolo en un elemento significativo para la realización de diagnóstico y valoración de la evaluación para los docentes y futuras investigaciones.  Abstract. The purpose of this study was to design and validate a questionnaire about the conceptions and perception of high school students about the assessment in the Physical Education class. This study was cross-sectional, descriptive non-experimental type, the validation process of the questionnaire had the participation of eight experts, physical education teachers (six doctors and two magister in the area), who finally determined the number of questions established for the questionnaire. The application of the instrument was made with 355 students from the metropolitan area of ​​Valle de Aburrá (Antioquia-Colombia). The sample was non-probabilistic; the information process was carried out using SPSS v23 software. The questionnaire is structured in four dimensions: conceptions, actors, instruments-moments and content. The main conclusion of the study derived from the content validity process (CVR) and the reliability analysis demonstrates that the instrument is successful and adequate, making it a significant element for carrying out diagnosis and assessment for teachers and future researches.

PREDICTION OF MUSCLE FORCES USING STATIC OPTIMIZATION FOR DIFFERENT CONTRACTILE CONDITIONS

2013 ◽  
Vol 13 (03) ◽  
pp. 1350022 ◽  
Author(s):  
YUNUS ZIYA ARSLAN ◽  
AZIM JINHA ◽  
MOTOSHI KAYA ◽  
WALTER HERZOG
Keyword(s):  
Cost Function ◽  
Fiber Type ◽  
Degree Of Freedom ◽  
Muscle Forces ◽  
Cross Sectional ◽  
Satisfactory Description ◽  
New Approach ◽  
Force Sharing ◽  
Synergistic Muscles ◽  
The Cost

In this study, we introduced a novel cost function for the prediction of individual muscle forces for a one degree-of-freedom musculoskeletal system. Unlike previous models, the new approach incorporates the instantaneous contractile conditions represented by the force-length and force-velocity relationships and accounts for physiological properties such as fiber type distribution and physiological cross-sectional area (PCSA) in the cost function. Using this cost function, it is possible to predict experimentally observed features of force-sharing among synergistic muscles that cannot be predicted using the classical approaches. Specifically, the new approach allows for predictions of force-sharing loops of agonistic muscles in one degree-of-freedom systems and for simultaneous increases in force in one muscle and decreases in a corresponding agonist. We concluded that the incorporation of the contractile conditions in the weighting of cost functions provides a natural way to incorporate observed force-sharing features in synergistic muscles that have eluded satisfactory description.

Hemodynamic Measurements in Human Arterial Casts, and Their Correlation With Histology and Luminal Area

1980 ◽  
Vol 102 (3) ◽  
pp. 247-251 ◽  
Author(s):  
M. H. Friedman ◽  
C. B. Bargeron ◽  
G. M. Hutchins ◽  
F. F. Mark ◽  
O. J. Deters
Keyword(s):  
Laser Doppler Anemometer ◽  
Longitudinal Variation ◽  
Sectional Area ◽  
Vascular Response ◽  
Velocity Measurements ◽  
Cross Sectional ◽  
New Approach ◽  
Flow Acceleration ◽  
Luminal Area ◽  
Hemodynamic Measurements

A new approach is presented for studying the vascular response to hemodynamic stress. A laser doppler anemometer is used to make velocity measurements very near the walls of human arterial casts; these measurements are then correlated with the histology of the artery from which the cast was made. Several illustrative results are given which suggest that the velocity profiles along the outer walls of aortic bifurcations may be significantly determined by the longitudinal variation of cross-sectional area. The shapes of these profiles were qualitatively different for each cast studied. In one specimen, the location of initial lipid deposits appeared to correlate with flow acceleration.

Metacognitions, Emotions, and Procrastination

2006 ◽  
Vol 20 (3) ◽  
pp. 319-326 ◽  
Author(s):  
Marcantonio M. Spada ◽  
Kalliopi Hiou ◽  
Ana V. Nikcevic
Keyword(s):  
Multiple Regression ◽  
Depression Scale ◽  
Regression Analyses ◽  
Cross Sectional ◽  
Convenience Sample ◽  
Four Dimensions ◽  
Decisional Procrastination ◽  
Penn State ◽  
State Worry ◽  
Anxiety Depression

The present study explored the relationships between metacognitions, negative emotions, and procrastination. A convenience sample of 179 participants completed the following questionnaires: General Procrastination Scale, Decisional Procrastination Scale, Meta-cognitions Questionnaire 30, Penn State Worry Questionnaire and Hospital Anxiety and Depression Scale. A cross-sectional design was adopted and data analysis consisted of correlation and multiple regression analyses. One dimension of metacognitions was found to be positively and significantly correlated with behavioral procrastination. Four dimensions of metacognitions were found to be positively and significantly correlated with decisional procrastination. Positive and significant relationships were also observed between anxiety, depression and behavioral procrastination; and between anxiety, depression, worry, and decisional procrastination. Multiple regression analyses indicated that depression and beliefs about cognitive confidence independently predicted behavioral procrastination, and that depression and positive beliefs about worry independently predicted decisional procrastination. These preliminary results would seem to suggest that metacognitive theory may be relevant to understanding procrastination.

Factors Controlling the Change of Shape of Certain Nemertean and Turbellarian Worms

1958 ◽  
Vol 35 (4) ◽  
pp. 731-748 ◽  
Author(s):  
R. B. CLARK ◽  
J. B. COWEY
Keyword(s):  
Water Conservation ◽  
Ecological Factors ◽  
Longitudinal Axis ◽  
The Body ◽  
Cross Sectional ◽  
Ciliary Action ◽  
Theoretical Predictions ◽  
Observed Behaviour ◽  
Body Wall Musculature ◽  
Sectional Shape

1. Nemerteans and turbellarians have an inextensible fibre system around them in the form of a lattice of left- and right-handed spirals. The effect of this system on the change of shape on these worms has been analysed theoretically and compared with the observed behaviour of nine species of turbellarian and nemertean from widely differing habitats. 2. The following theoretical relationships have been studied: (a) Variation of the angle between the geodesics and the longitudinal axis of the worm during changes in length, and the role of the fibre system in limiting changes in length of the animal. (b) The change in cross-sectional shape during changes in length. (c) The extension of the fibres and the extensibility of the worms, assuming the fibres of the lattice to be elastic. 3. The species investigated conform with the theoretical predictions to varying degrees and have been grouped accordingly: (a) Geonemertes dendyi and Rhynchodemus bilineatus have low extensibilities and fit the prediction well. They are nearly circular in cross-section at all lengths as a result of their low extensibility and this is related to their terrestrial habit and need for water conservation. (b) Amphiporus lactifloreus, Lineus gesserensis and L. longissimus are moderately flattened in the relaxed position and have extensibilities between 6 and 10. They are marine crawling forms using cilia for locomotion and so must present a fairly large ciliated surface to the substratum. The fibre system does not limit contraction; the compression of the epithelial cells causes the observed extensibilities to fall a little short of the theoretical values. (c) Cerebratulus lacteus, Malacobdella grossa, Polycelis nigra and Dendrocoelum lacteum are very flattened forms and have very high theoretical extensibilities, but very low observed ones. The factors causing this are the thickness of the body-wall musculature (Cerebratulus), the limiting effect of longitudinal and circular reticulin fibres in the muscle layers, and the presence of dorso-ventral and diagonal muscles. Their flattened form is correlated with ecological factors (with swimming in Cerebratulus, with its parasitic life in the mantle of bivalves in Melacobdella) or with physical ones in turbellarians where a permanently flattened form is necessary for these worms to move by ciliary action.

Design for Desired Mode Shapes: Preliminary Results

1998 ◽  
Author(s):  
Elizabeth K. Lai ◽  
G. K. Ananthasuresh
Keyword(s):  
Finite Element ◽  
Feasibility Study ◽  
Mode Shape ◽  
Longitudinal Axis ◽  
Mode Shapes ◽  
Future Research ◽  
Structural Members ◽  
Element Analysis ◽  
Cross Sectional ◽  
Made In

Abstract This paper is concerned with the shape optimization of structures to attain prescribed normal mode shapes. Optimizing structural members in order to have desired mode shapes, besides the desired natural frequencies, is of interest in some applications at both macro and micro scales. After reviewing the relevant past work on the “inverse mode shape” problem, a feasibility study using the lumped spring-mass models and finite element models of an axially vibrating bar is presented. Based on the observations made in the feasibility study with bars, a meaningful optimization problem is formulated and solved. Using finite element analysis and numerical optimization, a method for designing beam-like structures for prescribed mode shapes is developed. The method is demonstrated with an example of designing the cross-sectional area profile of a beam along its longitudinal axis to get a desired fundamental mode shape. The nonuniqueness of the solution is noted and avenues for future research are identified.

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