scholarly journals Control and Optimization of Interfacial Flows Using Adjoint-Based Techniques

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 156
Author(s):  
Alexandru Fikl ◽  
Vincent Le Chenadec ◽  
Taraneh Sayadi
Keyword(s):  
Characteristic Function ◽  
Two Dimensions ◽  
Interfacial Flows ◽  
Volume Of Fluid Method ◽  
Optimal Solutions ◽  
One Dimensional ◽  
Open Questions ◽  
Gradient Computation ◽  
Truncated Newton ◽  
Future Work

The applicability of adjoint-based gradient computation is investigated in the context of interfacial flows. Emphasis is set on the approximation of the transport of a characteristic function in a potential flow by means of an algebraic volume-of-fluid method. A class of optimisation problems with tracking-type functionals is proposed. Continuous (differentiate-then-discretize) and discrete (discretize-then-differentiate) adjoint-based gradient computations are formulated and compared in a one-dimensional configuration, the latter being ultimately used to perform optimisation in two dimensions. The gradient is used in truncated Newton and steepest descent optimisers, and the algorithms are shown to recover optimal solutions. These validations raise a number of open questions, which are finally discussed with directions for future work.

scholarly journals Assessing a Linear Nanosystem's Limiting Reliability from its Components

2008 ◽  
Vol 45 (03) ◽  
pp. 879-887 ◽  
Author(s):  
Nader Ebrahimi
Keyword(s):  
Present State ◽  
Size Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Present Moment ◽  
One Dimensional ◽  
The One ◽  
Fixed Moment ◽  
Nanosized Systems

Nanosystems are devices that are in the size range of a billionth of a meter (1 x 10-9) and therefore are built necessarily from individual atoms. The one-dimensional nanosystems or linear nanosystems cover all the nanosized systems which possess one dimension that exceeds the other two dimensions, i.e. extension over one dimension is predominant over the other two dimensions. Here only two of the dimensions have to be on the nanoscale (less than 100 nanometers). In this paper we consider the structural relationship between a linear nanosystem and its atoms acting as components of the nanosystem. Using such information, we then assess the nanosystem's limiting reliability which is, of course, probabilistic in nature. We consider the linear nanosystem at a fixed moment of time, say the present moment, and we assume that the present state of the linear nanosystem depends only on the present states of its atoms.

The Structure of Emotional Response: 1984 Presidential Candidates

1988 ◽  
Vol 82 (3) ◽  
pp. 737-761 ◽  
Author(s):  
George E. Marcus
Keyword(s):  
Emotional Response ◽  
Two Dimensions ◽  
Negative Emotionality ◽  
One Dimensional ◽  
Presidential Candidates ◽  
The Past ◽  
Emotional Appraisal ◽  
Psychological Models ◽  
Dimensional Models ◽  
Feeling Thermometer

Over the past two decades psychological models of affect have changed from valence (one-dimensional) models to multiple-dimensional models. The most recent models, circumplex models, are two-dimensional. Feeling thermometer measures, which derive their theoretical logic from earlier (valence) models of emotional appraisal, are shown to be confounded. Underlying the variation obtained using feeling thermometer measures are two dimensions of emotional response, mastery (positive emotionality) and threat (negative emotionality). Analysis of the 1984 NES survey suggests that positive emotional response is twice as influential as negative emotional response in predicting presidential candidate vote disposition to the presidential candidates. Reliance on emotional response is shown to be uniformly influential across various strata of the electorate.Policy considerations have little direct influence on vote disposition, though policy considerations are indirectly related to vote disposition through the influence of issues on the degree of feelings of threat evoked by the candidates.

scholarly journals THE EFFECT OF THE THIRD DIMENSION ON ROUGH SURFACES FORMED BY SEDIMENTING PARTICLES IN QUASI-TWO-DIMENSIONS

2002 ◽  
Vol 16 (08) ◽  
pp. 1217-1223 ◽  
Author(s):  
K. V. MCCLOUD ◽  
M. L. KURNAZ
Keyword(s):  
Two Dimensions ◽  
Scaling Analysis ◽  
Silica Spheres ◽  
Two Dimensional ◽  
One Dimensional ◽  
The Third ◽  
Roughness Exponent ◽  
Third Dimension ◽  
Dimensional Cell ◽  
Roughness Exponents

The roughness exponent of surfaces obtained by dispersing silica spheres into a quasi-two-dimensional cell is examined. The cell consists of two glass plates separated by a gap, which is comparable in size to the diameter of the beads. Previous work has shown that the quasi-one-dimensional surfaces formed have two roughness exponents in two length scales, which have a crossover length about 1 cm. We have studied the effect of changing the gap between the plates to a limit of about twice the diameter of the beads. If the conventional scaling analysis is performed, the roughness exponent is found to be robust against changes in the gap between the plates; however, the possibility that scaling does not hold should be taken seriously.

scholarly journals Digital methods for measuring grain size parameters of aggregate–binder mixtures.

2013 ◽  
Vol 47 (4) ◽  
pp. 1834
Author(s):  
E. Profitis ◽  
D. Kapatos ◽  
E. Chatzitheodoridis ◽  
D. Xirouchakis ◽  
C. Loupasakis
Keyword(s):  
Three Dimensional ◽  
Two Dimensions ◽  
Geometrical Parameters ◽  
Bituminous Mixtures ◽  
Dimensional Measurements ◽  
Digital Methods ◽  
Significant Cost Reduction ◽  
Future Work ◽  
Grain Size Parameters ◽  
Exact Separation

Geometrical parameters of natural and crushed aggregates such as grain length, perimeter, area, etc., underline the shape and flakiness indices definition. The latter indices have a measurable effect on the mechanical properties of aggregates–binder mixtures, e.g. concrete, mortar, bituminous mixtures. In this work, digital methods were developed with the mathematical software Matlab, by applying a statistical method called k-means clustering for the exact separation between background and aggregates to compute the aforementioned properties. The overall code can be applied in real time by analysing quickly a large volume of data with accuracy and significant cost reduction. Currently, only the two dimensions of the grains could be measured. Future work will focus on full three-dimensional measurements by comparing paired images taken from different angles but also aggregate segmentation in case of touching particles.

scholarly journals Numerical Simulation of the Fused Deposition Modeling for the Manufacturing of Parts with both High Geometric Fidelity and Mechanical Quality

2021 ◽  
Vol 14 (6) ◽  
pp. 712-725
Author(s):  
Holm Altenbach ◽  
◽  
G´abor Janiga ◽  
Rene Androsch ◽  
Mario Beiner ◽  
...  
Keyword(s):  
Fused Deposition Modeling ◽  
Two Dimensions ◽  
Volume Of Fluid Method ◽  
Ansys Fluent ◽  
Mechanical Parts ◽  
Fused Deposition ◽  
Modeling Process ◽  
Mechanical Quality ◽  
Deposition Modeling ◽  
Manufacturing Methods

With increasing usage of additive manufacturing methods for mechanical parts the need for precise and reliable simulations of the manufacturing process increases as well. In this paper various com- putations suited for simulating the fused deposition modeling process are considered in two dimensions. In fused deposition modeling a molten polymer is laid down on a prescribed path before the cooling of the melt begins. The occuring flows are treated as multiphase flows. To model the deposition of the filament, methods of computational fluid dynamics are used in ANSYS-Fluent, namely the volume of fluid method (VOF). Different numerical experiments are simulated

Taking Skills Seriously: Toward an Integrative Model and Agenda for Social, Emotional, and Behavioral Skills

2020 ◽  
pp. 096372142097861
Author(s):  
Christopher J. Soto ◽  
Christopher M. Napolitano ◽  
Brent W. Roberts
Keyword(s):  
Social Relationships ◽  
Social Engagement ◽  
Integrative Model ◽  
Self Management ◽  
Social Emotional ◽  
Behavioral Skills ◽  
Emotional Resilience ◽  
Assessment Development ◽  
Open Questions ◽  
Future Work

Success in life is influenced by more than cognitive ability and opportunity. Success is also influenced by social, emotional, and behavioral (SEB) skills: a person’s capacities to maintain social relationships, regulate emotions, and manage goal- and learning-directed behaviors. In this article, we propose an integrative model that defines SEB skills as capacities (what someone is capable of doing) rather than personality traits (what someone tends to do) and identifies five major skill domains: social engagement, cooperation, self-management, emotional resilience, and innovation. We then argue that operational measures of SEB skills should reflect rather than obscure the distinction between skills and traits. Finally, we propose an agenda for future work by highlighting open questions and hypotheses about the assessment, development, and outcomes of SEB skills as well as interventions and public policy targeting these skills.

scholarly journals Evaluation of a VERT-based module for proton radiotherapy education and training

2020 ◽  
pp. 1-5
Author(s):  
Amber Rabus ◽  
Mike C. Kirby ◽  
Laura Nasole ◽  
Pete Bridge
Keyword(s):  
Assessment Tool ◽  
New Technology ◽  
Statistical Significance ◽  
Basic Knowledge ◽  
Teaching Session ◽  
Open Questions ◽  
Before And After ◽  
Long Term Impact ◽  
Dose Deposition ◽  
Future Work

Abstract Introduction: In many countries, there is a skills gap in proton therapy with many staff unprepared to work with the new technology. The new Virtual Environment for Radiotherapy Training (VERT) proton module provides learners with a simulated proton machine 3D environment. This project aimed to evaluate the role of VERT in training the radiotherapy workforce for the future use of protons. Methods: A practical teaching session using VERT was deployed after a traditional teaching session had provided basic knowledge. A questionnaire deployed before and after VERT enabled comparison of knowledge while a combination of Likert and open questions gathered participant feedback concerning the initiative. Results: A total of 38 students provided evaluation of the session. Overall, there were high levels of satisfaction and enjoyment with 35 participants reporting enjoyment and 36 indicating that the event be repeated. Discussion: Participants felt that they had learned from the experience, although quantitative data lacked statistical significance to demonstrate this. All participants agreed that VERT had provided improved understanding of proton dose deposition arising from visualisation of beams and dose deposition. Most participants agreed that the simulation was realistic and that it had improved their understanding. Feedback in relation to future sessions concerned smaller group sizes, more patient cases, more time and additional clinical datasets. Conclusion: A proton simulation module has been shown to be an enjoyable teaching tool that improves students’ confidence in their knowledge of the underpinning theory and clinical usage of the modality. Learners felt better prepared to encounter protons in clinical practice. Future work will build on these findings using smaller group work and a more robust assessment tool to identify long-term impact of the training.

scholarly journals Chaotic Behavior of One-Dimensional Cellular Automata Rule 24

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zujie Bie ◽  
Qi Han ◽  
Chao Liu ◽  
Junjian Huang ◽  
Lepeng Song ◽  
...  
Keyword(s):  
Cellular Automata ◽  
Characteristic Function ◽  
Symbolic Dynamics ◽  
Bernoulli Shift ◽  
Chaotic Behavior ◽  
Class Ii ◽  
Chaotic Attractors ◽  
One Dimensional ◽  
Dynamical Behaviors ◽  
Shift Map

Wolfram divided the 256 elementary cellular automata rules informally into four classes using dynamical concepts like periodicity, stability, and chaos. Rule 24, which is Bernoulliστ-shift rule and is member of Wolfram’s class II, is said to be simple as periodic before. Therefore, it is worthwhile studying dynamical behaviors of four rules, whether they possess chaotic attractors or not. In this paper, the complex dynamical behaviors of rule 24 of one-dimensional cellular automata are investigated from the viewpoint of symbolic dynamics. We find that rule 24 is chaotic in the sense of both Li-Yorke and Devaney on its attractor. Furthermore, we prove that four rules of global equivalenceε52of cellular automata are topologically conjugate. Then, we use diagrams to explain the attractor of rule 24, where characteristic function is used to describe the fact that all points fall into Bernoulli-shift map after two iterations under rule 24.

An Instrument for One- or Two-Dimensional Tracking

1965 ◽  
Vol 21 (1) ◽  
pp. 307-312
Author(s):  
William C. Roehrig
Keyword(s):  
Low Cost ◽  
Two Dimensions ◽  
Two Dimensional ◽  
Error Signal ◽  
One Dimensional ◽  
Constant Torque ◽  
Sinusoidal Motion ◽  
The Cross ◽  
Target Path

A rugged electro-mechanical tracking apparatus of simple, low-cost construction is described. The apparatus can be used for one-dimensional tracking by connecting only the longitudinal motor, thus forcing the target to move back and forth in either simple sinusoidal motion or according to the sum of two or three sinusoids. The relative phases of the three sinusoids can be rapidly altered, as can the amplitudes (within limits) of each of the sinusoids. The frequency of the sinusoids can be changed either independently or conjointly. By also connecting the cross-feed motor, an essentially unpredictable target path in two dimensions is obtained, and this path can be rapidly altered by changing cams, and/or frequency, amplitude, and phase of the sinusoids. Movement of the cursor is by low, constant torque lathe-type controls. The distance the cursor moves per each rotation of the controls, can be altered for either or both of the controls. A continuous error signal is generated which is directly proportional to the distance the cursor is off target in any direction.

Differences in the Heat Transfer at the Core-Reflector Boundary of the PBMR Due to the Use of Different Numerical Methods

2009 ◽  
Author(s):  
Pieter S. du Toit ◽  
Onno Ubbink
Keyword(s):  
Two Dimensions ◽  
Heat Sources ◽  
Coarse Mesh ◽  
One Dimensional ◽  
Root Cause ◽  
The Core ◽  
Modified Method ◽  
The Difference ◽  
Horizontal Slice ◽  
Mesh Cell

The PBMR (Pebble Bed Modular Reactor) is a High-Temperature Gas-cooled Reactor (HTGR) concept. One of the exercises of the PBMR benchmark of the Organization for Economic Cooperation and Development (OECD) is a steady state two-dimensional (2D) thermal-hydraulics simulation of a simplified PBMR with prescribed heat sources. Two different programs were used to model this exercise. They predicted similar core temperatures but the side reflector temperatures next to the core differed by more than 30 °C (when using a relatively coarse mesh). The underlying methods define temperatures at either vertices (VC) or at mesh cell centres (CC). A study was undertaken using one-dimensional (1D) implementations of the VC and CC methods to model a horizontal slice through the core. This study revealed the root cause of the different predictions. A modified version of the 1D CC method was developed that essentially predicts the same temperatures as the VC method. The extension of the modified method to two dimensions is under investigation. If the difference in predicted temperatures next to the core can be eliminated or reduced, then the focus can shift to other differences between the results of the two programs.

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