scholarly journals Walking on Kendall’s Shape Space: Understanding Shape Spaces and Their Coordinate Systems

2020 ◽  
Vol 47 (4) ◽  
pp. 334-352
Author(s):  
Christian Peter Klingenberg
Keyword(s):  
Shape Change ◽  
Shape Space ◽  
Three Dimensions ◽  
Simulation Studies ◽  
Shape Spaces ◽  
Closed Surfaces ◽  
Local Approximations ◽  
Quality Of Approximation ◽  
Available Information

Abstract More and more analyses of biological shapes are using the techniques of geometric morphometrics based on configurations of landmarks in two or three dimensions. A fundamental concept at the core of these analyses is Kendall’s shape space and local approximations to it by shape tangent spaces. Kendall’s shape space is complex because it is a curved surface and, for configurations with more than three landmarks, multidimensional. This paper uses the shape space for triangles, which is the surface of a sphere, to explore and visualize some properties of shape spaces and the respective tangent spaces. Considerations about the dimensionality of shape spaces are an important step in understanding them, and can offer a coordinate system that can translate between positions in the shape space and the corresponding landmark configurations and vice versa. By simulation studies “walking” along that are great circles around the shape space, each of them corresponding to the repeated application of a particular shape change, it is possible to grasp intuitively why shape spaces are curved and closed surfaces. From these considerations and the available information on shape spaces for configurations with more than three landmarks, the conclusion emerges that the approach using a tangent space approximation in general is valid for biological datasets. The quality of approximation depends on the scale of variation in the data, but existing analyses suggest this should be satisfactory to excellent in most empirical datasets.

Evaluation of the Academic Setting in Spain 1This study was financed by the University of Oviedo.

1995 ◽  
Vol 11 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Juan Fernández ◽  
Miguel A. Mateo ◽  
José Muñiz
Keyword(s):  
Higher Education ◽  
Decision Making ◽  
Social Climate ◽  
Three Dimensions ◽  
Academic Setting ◽  
Teaching And Research ◽  
Evaluation Questionnaire ◽  
University Teachers ◽  
The University

The conditions are investigated in which Spanish university teachers carry out their teaching and research functions. 655 teachers from the University of Oviedo took part in this study by completing the Academic Setting Evaluation Questionnaire (ASEQ). Of the three dimensions assessed in the ASEQ, Satisfaction received the lowest ratings, Social Climate was rated higher, and Relations with students was rated the highest. These results are similar to those found in two studies carried out in the academic years 1986/87 and 1989/90. Their relevance for higher education is twofold because these data can be used as a complement of those obtained by means of students' opinions, and the crossing of both types of data can facilitate decision making in order to improve the quality of the work (teaching and research) of the university institutions.

scholarly journals Techniques for Mitigating the Effects of Smoke Taint While Maintaining Quality in Wine Production: A Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1672
Author(s):  
Ysadora A. Mirabelli-Montan ◽  
Matteo Marangon ◽  
Antonio Graça ◽  
Christine M. Mayr Marangon ◽  
Kerry L. Wilkinson
Keyword(s):  
Global Perspective ◽  
Wine Industry ◽  
Wine Production ◽  
Specific Data ◽  
Main Research ◽  
Initial Severity ◽  
The Subject ◽  
Available Information

Smoke taint has become a prominent issue for the global wine industry as climate change continues to impact the length and extremity of fire seasons around the world. Although the issue has prompted a surge in research on the subject in recent years, no singular solution has yet been identified that is capable of maintaining the quality of wine made from smoke-affected grapes. In this review, we summarize the main research on smoke taint, the key discoveries, as well as the prevailing uncertainties. We also examine methods for mitigating smoke taint in the vineyard, in the winery, and post production. We assess the effectiveness of remediation methods (proposed and actual) based on available research. Our findings are in agreement with previous studies, suggesting that the most viable remedies for smoke taint are still the commercially available activated carbon fining and reverse osmosis treatments, but that the quality of the final treated wines is fundamentally dependent on the initial severity of the taint. In this review, suggestions for future studies are introduced for improving our understanding of methods that have thus far only been preliminarily investigated. We select regions that have already been subjected to severe wildfires, and therefore subjected to smoke taint (particularly Australia and California) as a case study to inform other wine-producing countries that will likely be impacted in the future and suggest specific data collection and policy implementation actions that should be taken, even in countries that have not yet been impacted by smoke taint. Ultimately, we streamline the available information on the topic of smoke taint, apply it to a global perspective that considers the various stakeholders involved, and provide a launching point for further research on the topic.

scholarly journals Transporting Deformations of Face Emotions in the Shape Spaces: A Comparison of Different Approaches

2021 ◽  
Author(s):  
Paolo Piras ◽  
Valerio Varano ◽  
Maxime Louis ◽  
Antonio Profico ◽  
Stanley Durrleman ◽  
...  
Keyword(s):  
Computer Vision ◽  
Shape Change ◽  
Surface Matching ◽  
Human Face ◽  
Matching Algorithm ◽  
Mathematical Procedure ◽  
Shape Spaces ◽  
Diffeomorphic Deformation ◽  
Common Application ◽  
Scientific Fields

AbstractStudying the changes of shape is a common concern in many scientific fields. We address here two problems: (1) quantifying the deformation between two given shapes and (2) transporting this deformation to morph a third shape. These operations can be done with or without point correspondence, depending on the availability of a surface matching algorithm, and on the type of mathematical procedure adopted. In computer vision, the re-targeting of emotions mapped on faces is a common application. We contrast here four different methods used for transporting the deformation toward a target once it was estimated upon the matching of two shapes. These methods come from very different fields such as computational anatomy, computer vision and biology. We used the large diffeomorphic deformation metric mapping and thin plate spline, in order to estimate deformations in a deformational trajectory of a human face experiencing different emotions. Then we use naive transport (NT), linear shift (LS), direct transport (DT) and fanning scheme (FS) to transport the estimated deformations toward four alien faces constituted by 240 homologous points and identifying a triangulation structure of 416 triangles. We used both local and global criteria for evaluating the performance of the 4 methods, e.g., the maintenance of the original deformation. We found DT, LS and FS very effective in recovering the original deformation while NT fails under several aspects in transporting the shape change. As the best method may differ depending on the application, we recommend carefully testing different methods in order to choose the best one for any specific application.

scholarly journals The conceptualisation of vital communities related to ageing in place: a scoping review

2021 ◽  
Author(s):  
Katinka E. Pani-Harreman ◽  
Joop M. A. van Duren ◽  
Gertrudis I. J. M. Kempen ◽  
Gerrie J. J. W. Bours
Keyword(s):  
Older People ◽  
Scoping Review ◽  
Health Care Professionals ◽  
Living Environment ◽  
Three Dimensions ◽  
Informal Networks ◽  
Ageing In Place ◽  
Additional Support ◽  
People Today

AbstractOlder people today are more likely to age in their own private living environment. However, many face declining health and/or other issues that affect their ability to live independently and necessitate additional support. Such support can be provided by formal networks, but a considerable part can also be offered by informal networks of older people themselves. Going beyond these networks, older people can additionally and perhaps even more substantially benefit from vital communities. Nevertheless, even though this term is increasingly common in the literature, its meaning remains indistinct. A more thorough understanding of this concept might provide valuable knowledge that health care professionals, researchers and community workers can use to offer meaningful and effective support. The purpose of this paper is to draw on existing empirical research on vital communities to build knowledge of the different descriptions and dimensions of the concept. Arksey and O’Malley’s scoping review methodology was adopted. Our search, conducted on 23 March 2020 and updated on 06 January 2021, yielded 4433 articles, of which six articles were included in the scoping review. We deduced that the conceptualisation of a vital community is based on three dimensions: the aim of a vital community, the processes behind a vital community and the typical characteristics of a vital community. None of the selected studies have mapped all three dimensions. Nevertheless, we assume that understanding all three matters when vital communities aim to contribute to the quality of life of people ageing in place.

scholarly journals A Simulation Model of Construction Projects Executed in Random Conditions with the Overlapping Construction Works

2021 ◽  
Vol 13 (11) ◽  
pp. 5795
Author(s):  
Sławomir Biruk ◽  
Łukasz Rzepecki
Keyword(s):  
Simulation Model ◽  
Technological Process ◽  
Construction Projects ◽  
Working Time ◽  
Simulation Studies ◽  
Construction Methods ◽  
The Impact ◽  
Construction Works

Reducing the duration of construction works requires additional organizational measures, such as selecting construction methods that assure a shorter realization time, engaging additional resources, working overtime, or allowing construction works to be performed simultaneously in the same working units. The simultaneous work of crews may affect the quality of works and the efficiency of construction processes. This article presents a simulation model aimed at assessing the impact of the overlap period on the extension of the working time of the crews and the reduction of a repetitive project’s duration in random conditions. The purpose of simulation studies is to provide construction managers with guidelines when deciding on the dates of starting the sequential technological process lines realized by specialized working crews, for sustainable scheduling and organization of construction projects.

Radial generation of n-dimensional poisson processes

1984 ◽  
Vol 21 (03) ◽  
pp. 548-557
Author(s):  
M. P. Quine ◽  
D. F. Watson
Keyword(s):  
Poisson Process ◽  
Poisson Processes ◽  
Three Dimensions ◽  
Simulation Studies ◽  
Simple Method ◽  
Efficient Simulation ◽  
Nearest Neighbours

A simple method is proposed for the generation of successive ‘nearest neighbours' to a given origin in ann-dimensional Poisson process. It is shown that the method provides efficient simulation of random Voronoi polytopes. Results are given of simulation studies in two and three dimensions.

scholarly journals PARALLEL DELAUNAY REFINEMENT: ALGORITHMS AND ANALYSES

2007 ◽  
Vol 17 (01) ◽  
pp. 1-30 ◽  
Author(s):  
DANIEL A. SPIELMAN ◽  
SHANG-HUA TENG ◽  
ALPER ÜNGÖR
Keyword(s):  
Mesh Size ◽  
Constant Factor ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Delaunay Refinement ◽  
Steiner Points ◽  
Input Domain ◽  
Set Of Points ◽  
Refinement Algorithm

We present a parallel Delaunay refinement algorithm for generating well-shaped meshes in both two and three dimensions. Like its sequential counterparts, the parallel algorithm iteratively improves the quality of a mesh by inserting new points, the Steiner points, into the input domain while maintaining the Delaunay triangulation. The Steiner points are carefully chosen from a set of candidates that includes the circumcenters of poorly-shaped triangular elements. We introduce a notion of independence among possible Steiner points that can be inserted simultaneously during Delaunay refinements and show that such a set of independent points can be constructed efficiently and that the number of parallel iterations is O( log 2Δ), where Δ is the spread of the input — the ratio of the longest to the shortest pairwise distances among input features. In addition, we show that the parallel insertion of these set of points can be realized by sequential Delaunay refinement algorithms such as by Ruppert's algorithm in two dimensions and Shewchuk's algorithm in three dimensions. Therefore, our parallel Delaunay refinement algorithm provides the same shape quality and mesh-size guarantees as these sequential algorithms. For generating quasi-uniform meshes, such as those produced by Chew's algorithms, the number of parallel iterations is in fact O( log Δ). To the best of our knowledge, our algorithm is the first provably polylog(Δ) time parallel Delaunay-refinement algorithm that generates well-shaped meshes of size within a constant factor of the best possible.

Service journey quality: conceptualization, measurement and customer outcomes

2021 ◽  
Vol 32 (6) ◽  
pp. 1-27
Author(s):  
Elina Jaakkola ◽  
Harri Terho
Keyword(s):  
Service Quality ◽  
Service Delivery ◽  
Customer Loyalty ◽  
Financial Services ◽  
Three Dimensions ◽  
Service Research ◽  
Research Approach ◽  
Critical Determinant ◽  
Content Type

PurposeThe quality of the customer journey has become a critical determinant of successful service delivery in contemporary business. Extant journey research focuses on the customer path to purchase, but pays less attention to the touchpoints related to service delivery and consumption that are key for understanding customer experiences in service-intensive contexts. The purpose of this study is to conceptualize service journey quality (SJQ), develop measures for the construct and study its key outcomes.Design/methodology/approachThe study uses a discovery-oriented research approach to conceptualize SJQ by synthesizing theory and field-based insights from customer focus group discussions. Next, using consumer survey data (N = 278) from the financial services context, the authors develop measures for the SJQ. Finally, based on an additional survey dataset (N = 239), the authors test the nomological validity and predictive relevance of the SJQ.FindingsSJQ comprises of three dimensions: (1) journey seamlessness, (2) journey personalization and (3) journey coherence. This study demonstrates that SJQ is a critical driver of service quality and customer loyalty in contemporary business. This study finds that the loyalty link is partially mediated through service quality, indicating that SJQ explains loyalty above and beyond service quality.Research limitations/implicationsSince service quality only partially mediates the link between service journey quality and customer loyalty, future studies should examine alternative mediators, such as customer experience, for a more comprehensive understanding of the performance effects.Practical implicationsThe study offers concrete tools for service managers who wish to understand and develop the quality of service journeys.Originality/valueThis study advances the service journey concept, demonstrates that the quality of the service journey is a critical driver of customer performance and provides rigorous journey constructs for future service research.

Measurement of cortical plate volume based on CBCT of frontal teeth in studies with retrusion and normality

2021 ◽  
pp. 17-21
Author(s):  
N. G. Meskhiya ◽  
I. S. Kopetskiy ◽  
I. A. Nikolskaya ◽  
D. A. Eremin ◽  
O. N. Kovaleva
Keyword(s):  
Orthodontic Treatment ◽  
Soft Tissues ◽  
Three Dimensions ◽  
Cone Beam ◽  
Cortical Plate ◽  
Imaging Method ◽  
New Approach ◽  
Accuracy Of Measurements ◽  
Bone Structures

Cone Beam Computed Tomography (CBCT) is the preferred imaging method for a comprehensive orthodontic examination. Thanks to the development of this technique, clinicians today can make most accurate measurements without fear of errors associated with projection distortion or localization of landmarks on radiographs. The quality of CBCT images gives to orthodontists the ability to analyze bone structures, teeth (even impacted teeth), and soft tissue in three dimensions. The accuracy of measurements of hard and soft tissues from CBCT images determines the accuracy of diagnosis and treatment planning. A fundamentally new approach has been proposed, which makes it possible to thoroughly study the bone tissue surrounding the tooth at the stages of planning orthodontic treatment. Аnalysis of radiation studies of patients with dentoalveolar anomalies was carried out to select the optimal treatment tactics and to control its effectiveness.

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