scholarly journals Influence of sample slenderness and boundary conditions in triaxial test - a review

2019 ◽  
Vol 92 ◽  
pp. 02009
Author(s):  
Elena Peri ◽  
Lars Bo Ibsen ◽  
Benjaminn Nordahl Nielsen
Keyword(s):  
Boundary Conditions ◽  
Triaxial Test ◽  
Point Of View ◽  
Single Line ◽  
Triaxial Testing ◽  
Theoretical Point ◽  
Test Configuration ◽  
Fem Modelling ◽  
The Past ◽  
Made In

In the past decades an extensive work was done in order to improve the performance and increase the reliability of triaxial testing. Among the several changes made in order to solve the inaccuracies of the traditional test configuration, two of them are discussed in this paper: the sample slenderness [in other words, the H/D ratio] and the introduction of smooth end platens instead of the rough ones. By using H/D=1 and not the usual H/D=2 ratio, the formation of a single line-rapture and the bulge shape seem prevented. The smooth ends decrease the restrain at the top and bottom of the sample. From a theoretical point of view the effects of these changes are clear, but experimentally, the results coming from various studies are contradictory. The purpose of this paper is to elucidate the previous findings on the topic, including both laboratory and FEM modelling test programs.

scholarly journals Twinning in MAPbI3 at room temperature uncovered through Laue neutron diffraction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joachim Breternitz ◽  
Michael Tovar ◽  
Susan Schorr
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Point Of View ◽  
Temperature Structure ◽  
Theoretical Point ◽  
Laue Diffraction ◽  
The Past ◽  
Halide Perovskites

Abstract The crystal structure of MAPbI3, the signature compound of the hybrid halide perovskites, at room temperature has been a reason for debate and confusion in the past. Part of this confusion may be due to twinning as the material bears a phase transition just above room temperature, which follows a direct group–subgroup relationship and is prone to twinning. Using neutron Laue diffraction, we illustrate the nature of twinning in the room temperature structure of MAPbI3 and explain its origins from a group-theoretical point-of-view.

One Point of View: Let the Learning Disabled Learn

1986 ◽  
Vol 33 (5) ◽  
pp. 2
Author(s):  
Nancy Bley
Keyword(s):  
Learning Disabilities ◽  
Learning Disabled ◽  
Point Of View ◽  
Computer Assisted Instruction ◽  
Computer Assisted ◽  
Teacher Education Programs ◽  
Students With Special Needs ◽  
The Past ◽  
Assisted Instruction ◽  
Made In

The past ten or fifteen years have produced numerous changes in the field of education, particularly in mathematic. Many advances have been made in teacher education programs, in the use of mechanical aids, and particularly in the area of computers and computer-assisted instruction. At the same time awarenes has increased of the need to deal more effectively with students with special needs, or those more commonly described as having learning disabilities.

scholarly journals SPATIAL DETERMINISM AND TERRITORIAL PUBLIC ACTION IN FRANCE: CHALLENGES AND EVOLUTIONS

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Grégory BUSQUET
Keyword(s):  
Point Of View ◽  
Theoretical Point ◽  
Spatial Transformation ◽  
The Past ◽  
Urban Narrative ◽  
The People ◽  
Strategic Approach ◽  
Urban Project ◽  
The City

This article proposes a theoretical point of view in order to show the importance of the collective memory and the urban narrative in the strategic approach of the urban project. The capacity of a municipality to build a local narrative joining the past, the memory and the project, is examined in the second part of the article, in a case study of a collectivity confronted with the project of the Grand Paris and strong socio-spatial transformation since 1950. The conclusions of thirty deep interviews, conducted on the people involved in the city organization allow to differentiate legitimated and rejected places in the spaces of remembering, and the difficulties of this kind of municipalities to be pro active in the Grand Paris project.

scholarly journals The comparative method for policy studies: the thorny aspects

2019 ◽  
Vol 10 (1) ◽  
pp. 56-67
Author(s):  
Tatiana-Camelia Dogaru Cruceanu
Keyword(s):  
Comparative Research ◽  
Comparative Method ◽  
Policy Research ◽  
Point Of View ◽  
Decision Makers ◽  
Theoretical Point ◽  
Policy Studies ◽  
New Approach ◽  
The Past ◽  
Policy Systems

Abstract Over the past decades, the comparative method has attracted the attention of the theorists, and studies based on this approach have increased in applied policy research. In their daily and strategically policy decisions, the decision makers from local, regional and national levels use more and more the comparative research methods, especially due to interlinked relationship and the need for bench learning and benchmarking practices. The comparative method allows the actors to analyse other experiences, and thus to take decisions more efficient. This is a normal, an inevitable situation, when the unit of analysis is a country, a field of matters or a process where researchers compare cases from empirical or theoretical point of view. The purpose of this paper is to provide a critical view on the capacity of comparative method to foster knowledge in policy studies. The intention is to see and to explore the utility of comparative method for policy studies and policy analysis, since a new approach “evidence-based policymaking” arise, emphasising the importance of using evidence from other political and policy systems.

Notizen: On a Field-Theoretic Formulation of Scaling Laws in Molecular Scattering

1979 ◽  
Vol 34 (7) ◽  
pp. 897-898
Author(s):  
E. Ficocelli Varracchio
Keyword(s):  
Boundary Conditions ◽  
Inelastic Scattering ◽  
Ab Initio ◽  
Scaling Laws ◽  
Point Of View ◽  
Theoretical Point ◽  
Rotational Excitation ◽  
Molecular Scattering ◽  
Excitation Processes ◽  
The Relationship

Vibro-rotational excitation processes, in particle-diatom scattering, are considered from a field-theoretical point of view. It is shown that a relaxation of the relationship directly connecting boundary conditions and reference state, of the Green's functions of the theory’, can lead to a formulation of ab initio “scaling laws”, for both elastic and inelastic scattering.

Ivan Petrović, Photographer, Archivist and Artist: Interview with Ivan Petrović

2017 ◽  
pp. 4-9
Author(s):  
Miha Colner ◽  
Ivan Petrović
Keyword(s):  
Point Of View ◽  
Artistic Expression ◽  
Film Production ◽  
Theoretical Point ◽  
Artistic Practice ◽  
Photographic Image ◽  
The Past ◽  
Archival Work

Ivan Petrović (1973) has been working in the fields of photography and art for twenty years as a researcher, creator and collector. Since 1997, he has been creating and publishing photographic projects that reflect the spirit of space and time in which they are created, while in his works he uses both documentary approaches as well as research principles. In 2011, together with photographer Mihail Vasiljević, he founded a para-institution, the Centre for Photography (CEF). Despite lacking its own premises, infrastructure or funds for performing its activities, the institution deals with the search, preservation, collection and analysis of local photographic materials from recent history. In the past ten years, Petrović also moved his artistic practice beyond mere artistic expression, since he addresses the phenomena of photography from an analytical-theoretical point of view. His interest lies in the nature of the photographic image and its role in society and historiography. In this spirit, long-term projects such as Documents (1997–2008), Images (2002–), Portfolio Belgrade (2015–) and the latest film production were created. The interview with Ivan Petrović took place on 1 September 2017 in Belgrade. The main themes were the role of photography in the dominant history, the boundary between one’s own practice and archival work, photography as an art and the likes. Keywords: collection, documentary, photography's role, preservation, research

scholarly journals Gestural coordination at prosodic boundaries and its role for prosodic structure and speech planning processes

2014 ◽  
Vol 369 (1658) ◽  
pp. 20130397 ◽  
Author(s):  
Jelena Krivokapić
Keyword(s):  
Point Of View ◽  
Prosodic Structure ◽  
Multiple Functions ◽  
The Past ◽  
Prosodic Boundaries ◽  
Planning Processes ◽  
Speech Planning ◽  
Prosodic Boundary ◽  
Important Progress ◽  
Made In

Prosodic structure is a grammatical component that serves multiple functions in the production, comprehension and acquisition of language. Prosodic boundaries are critical for the understanding of the nature of the prosodic structure of language, and important progress has been made in the past decades in illuminating their properties. We first review recent prosodic boundary research from the point of view of gestural coordination. We then go on to tie in this work to questions of speech planning and manual and head movement. We conclude with an outline of a new direction of research which is needed for a full understanding of prosodic boundaries and their role in the speech production process.

NONLOCAL CONTINUUM ADAPTIVE ELASTIC BONE-COLUMN BUCKLING MODEL

2021 ◽  
Vol 21 (03) ◽  
pp. 2150015
Author(s):  
H. BENNACEUR ◽  
S. RAMTANI ◽  
T. OUTTAS ◽  
T. BOUKHAROUBA
Keyword(s):  
Bone Density ◽  
Beam Theory ◽  
Point Of View ◽  
Theoretical Point ◽  
Column Buckling ◽  
Strength Based ◽  
Buckling Failure ◽  
Euler Bernoulli Beam ◽  
Clinical Problems ◽  
Made In

It is well argued that stability-initiated failure dominates, especially in older bone, because of the instability of single trabeculae which is prone to inelastic buckling at stresses far less than expected for strength-based failure. It is also well known that when several horizontal struts have disappeared, trabecula fails due to compression-buckling load. In this contribution, our main goal is to improve, from theoretical point of view, the mechanistic understanding of bone buckling failure which is known to be at the core of important clinical problems. For that and with respect to previous works, an attempt is made in order to establish a simplified adaptive-beam buckling model, formulated within the context of the nonlocal adaptive continuum mechanics, from which numerical computations were performed in order to get a better knowledge about bone-column buckling mechanism affected by both bone density and bone density gradient distributions restricted to Euler–Bernoulli beam theory. An attempt is made to compare the experimental data with the response of our simplified model. For that, controlled buckling tests of single trabeculae were carried out from three medial tibia end sections (knee joint).

Physical properties of Class I methanol masers

2017 ◽  
Vol 13 (S336) ◽  
pp. 17-22 ◽  
Author(s):  
Silvia Leurini ◽  
Karl M. Menten
Keyword(s):  
Physical Properties ◽  
Recent Progress ◽  
Class Ii ◽  
Point Of View ◽  
Class I ◽  
Theoretical Point ◽  
The Past ◽  
Methanol Masers

AbstractAs first realised in the late 1980s, methanol masers come in two varieties, termed Class I and Class II. While Class II masers had observationally been extensively studied in the past, until recently relatively little attention was paid to Class I methanol masers due to their low luminosities compared to other maser transitions. In this review, we will focus on the recent progress in our understanding of Class I methanol masers both from an observational and from a theoretical point of view.

scholarly journals An Empirical Review of Automated Machine Learning

Computers ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Lorenzo Vaccaro ◽  
Giuseppe Sansonetti ◽  
Alessandro Micarelli
Keyword(s):  
Machine Learning ◽  
Computer Science ◽  
Research Work ◽  
Industrial Sector ◽  
Point Of View ◽  
Future Research ◽  
Theoretical Point ◽  
Academic Field ◽  
Automated Machine Learning ◽  
Made In

In recent years, Automated Machine Learning (AutoML) has become increasingly important in Computer Science due to the valuable potential it offers. This is testified by the high number of works published in the academic field and the significant efforts made in the industrial sector. However, some problems still need to be resolved. In this paper, we review some Machine Learning (ML) models and methods proposed in the literature to analyze their strengths and weaknesses. Then, we propose their use—alone or in combination with other approaches—to provide possible valid AutoML solutions. We analyze those solutions from a theoretical point of view and evaluate them empirically on three Atari games from the Arcade Learning Environment. Our goal is to identify what, we believe, could be some promising ways to create truly effective AutoML frameworks, therefore able to replace the human expert as much as possible, thereby making easier the process of applying ML approaches to typical problems of specific domains. We hope that the findings of our study will provide useful insights for future research work in AutoML.

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