scholarly journals A Survey on Latent Tree Models and Applications

2013 ◽  
Vol 47 ◽  
pp. 157-203 ◽  
Author(s):  
R. Mourad ◽  
C. Sinoquet ◽  
N. L. Zhang ◽  
T. Liu ◽  
P. Leray
Keyword(s):  
Graphical Models ◽  
Latent Variables ◽  
Simple Structure ◽  
Tree Model ◽  
The Past ◽  
Latent Tree Models ◽  
Tree Models ◽  
Complex Relationships ◽  
Latent Tree Model ◽  
Comprehensive Study

In data analysis, latent variables play a central role because they help provide powerful insights into a wide variety of phenomena, ranging from biological to human sciences. The latent tree model, a particular type of probabilistic graphical models, deserves attention. Its simple structure - a tree - allows simple and efficient inference, while its latent variables capture complex relationships. In the past decade, the latent tree model has been subject to significant theoretical and methodological developments. In this review, we propose a comprehensive study of this model. First we summarize key ideas underlying the model. Second we explain how it can be efficiently learned from data. Third we illustrate its use within three types of applications: latent structure discovery, multidimensional clustering, and probabilistic inference. Finally, we conclude and give promising directions for future researches in this field.

scholarly journals Latent Tree Models and Approximate Inference in Bayesian Networks

2008 ◽  
Vol 32 ◽  
pp. 879-900 ◽  
Author(s):  
Y. Wang ◽  
N. L. Zhang ◽  
T. Chen
Keyword(s):  
Bayesian Networks ◽  
Linear Time ◽  
Computational Cost ◽  
Approximate Inference ◽  
Tree Model ◽  
Approximation Accuracy ◽  
Latent Tree Models ◽  
Tree Models ◽  
Novel Method ◽  
Latent Tree Model

We propose a novel method for approximate inference in Bayesian networks (BNs). The idea is to sample data from a BN, learn a latent tree model (LTM) from the data offline, and when online, make inference with the LTM instead of the original BN. Because LTMs are tree-structured, inference takes linear time. In the meantime, they can represent complex relationship among leaf nodes and hence the approximation accuracy is often good. Empirical evidence shows that our method can achieve good approximation accuracy at low online computational cost.

Applying Item Response Trees to Personality Data in the Selection Context

2018 ◽  
Vol 22 (4) ◽  
pp. 1007-1018 ◽  
Author(s):  
David Michael LaHuis ◽  
Caitlin E. Blackmore ◽  
Kinsey Blue Bryant-Lees ◽  
Kristin Delgado
Keyword(s):  
Item Response ◽  
Personnel Selection ◽  
Decision Process ◽  
Latent Variables ◽  
Latent Variable ◽  
Decision Processes ◽  
Self Report ◽  
Tree Model ◽  
Tree Models ◽  
Better Than

Self-report personality scales are used frequently in personnel selection. Traditionally, researchers have assumed that individuals respond to items within these scales using a single-decision process. More recently, a flexible set of item response (IR) tree models have been developed that allow researchers to investigate multiple-decision processes. In the present research, we found that IR tree models fit the data better than a single-decision IR model when fitted to seven self-report personality scales used in a concurrent criterion-related validity study. In addition, we found evidence that the latent variable underlying the direction of a response (agree or disagree) decision process predicted job performance better than latent variables reflecting the other decision processes for the best fitting IR tree model.

Plant leaf recognition with shallow and deep learning: A comprehensive study

2020 ◽  
Vol 24 (6) ◽  
pp. 1311-1328
Author(s):  
Jozsef Suto
Keyword(s):  
Machine Learning ◽  
Plant Species ◽  
Research Area ◽  
Research Papers ◽  
Plant Leaf ◽  
Leaf Characteristics ◽  
The Past ◽  
The Earth ◽  
Test Sets ◽  
Comprehensive Study

Nowadays there are hundreds of thousands known plant species on the Earth and many are still unknown yet. The process of plant classification can be performed using different ways but the most popular approach is based on plant leaf characteristics. Most types of plants have unique leaf characteristics such as shape, color, and texture. Since machine learning and vision considerably developed in the past decade, automatic plant species (or leaf) recognition has become possible. Recently, the automated leaf classification is a standalone research area inside machine learning and several shallow and deep methods were proposed to recognize leaf types. From 2007 to present days several research papers have been published in this topic. In older studies the classifier was a shallow method while in current works many researchers applied deep networks for classification. During the overview of plant leaf classification literature, we found an interesting deficiency (lack of hyper-parameter search) and a key difference between studies (different test sets). This work gives an overall review about the efficiency of shallow and deep methods under different test conditions. It can be a basis to further research.

scholarly journals 3D Insights into the Effects of Captivity on Wolf Mastication and Their Tooth Marks; Implications in Ecological Studies of Both the Past and Present

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2323
Author(s):  
Lloyd A. Courtenay ◽  
Darío Herranz-Rodrigo ◽  
José Yravedra ◽  
José Mª Vázquez-Rodríguez ◽  
Rosa Huguet ◽  
...  
Keyword(s):  
Data Science ◽  
Surface Modifications ◽  
Human Populations ◽  
Ecological Studies ◽  
The Past ◽  
Carnivore Species ◽  
Different Populations ◽  
Complex Relationships ◽  
As Stress ◽  
Tooth Marks

Human populations have been known to develop complex relationships with large carnivore species throughout time, with evidence of both competition and collaboration to obtain resources throughout the Pleistocene. From this perspective, many archaeological and palaeontological sites present evidence of carnivore modifications to bone. In response to this, specialists in the study of microscopic bone surface modifications have resorted to the use of 3D modeling and data science techniques for the inspection of these elements, reaching novel limits for the discerning of carnivore agencies. The present research analyzes the tooth mark variability produced by multiple Iberian wolf individuals, with the aim of studying how captivity may affect the nature of tooth marks left on bone. In addition to this, four different populations of both wild and captive Iberian wolves are also compared for a more in-depth comparison of intra-species variability. This research statistically shows that large canid tooth pits are the least affected by captivity, while tooth scores appear more superficial when produced by captive wolves. The superficial nature of captive wolf tooth scores is additionally seen to correlate with other metric features, thus influencing overall mark morphologies. In light of this, the present study opens a new dialogue on the reasons behind this, advising caution when using tooth scores for carnivore identification and contemplating how elements such as stress may be affecting the wolves under study.

Old and New Results for First Order Periodic ODEs without Uniqueness: a Comprehensive Study by Lower and Upper Solutions

2004 ◽  
Vol 4 (3) ◽  
Author(s):  
Franco Obersnel ◽  
Pierpaolo Omari
Keyword(s):  
Cauchy Problem ◽  
Differential Equations ◽  
Lower And Upper Solutions ◽  
Elementary Approach ◽  
Qualitative Properties ◽  
First Order ◽  
The Past ◽  
The Cauchy Problem ◽  
Qualitative Properties Of Solutions ◽  
Comprehensive Study

AbstractAn elementary approach, based on a systematic use of lower and upper solutions, is employed to detect the qualitative properties of solutions of first order scalar periodic ordinary differential equations. This study is carried out in the Carathéodory setting, avoiding any uniqueness assumption, in the future or in the past, for the Cauchy problem. Various classical and recent results are recovered and generalized.

scholarly journals Interactive Modeling of 3D Tree with Ball B-Spline Curves

2009 ◽  
Vol 8 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Zhongke Wu ◽  
Mingquan Zhou ◽  
Xingce Wang
Keyword(s):  
Iterated Function Systems ◽  
Interactive Methods ◽  
Tree Model ◽  
B Spline ◽  
Spline Curves ◽  
Novel Approach ◽  
Iterated Function ◽  
Tree Models ◽  
Generating Tree ◽  
L Systems

A novel approach to modeling realistic tree easily through interactive methods based on ball B-Spline Curves (BBSCs) and an efficient graph based data structure of tree model is proposed in the paper. As BBSCs are flexible for modifying, deforming and editing, these methods provide intuitive interaction and more freedom for users to model trees. If conjuncted with other methods like generating tree models through L-systems or iterated function systems (IFS), the models are more realistic and natural through modifying and editing. The method can be applied to the design of bonsai tree models.

Yugoslavism: Some Aspects and Comments

1974 ◽  
Vol 1 (1) ◽  
pp. 192-201 ◽  
Author(s):  
Dimitrije Djordjević
Keyword(s):  
Salt Lake ◽  
Salt Lake City ◽  
Rocky Mountain ◽  
The Past ◽  
Nineteenth And Twentieth Centuries ◽  
Lake City ◽  
Post War ◽  
Science Association ◽  
Social Science Association ◽  
Comprehensive Study

AbstractAt the April, 1972, Annual Meeting of the Rocky Mountain Social Science Association, which took place in Salt Lake City, five young American scholars presented papers dealing with various aspects of Yugoslavism in the nineteenth and twentieth centuries. The papers and subsequent discussions were interesting from two standpoints. First, the authors belong to the youngest generation of American scholars familiar with the several Yugoslav languages and with Yugoslav archives and other sources. Second, the topic of Yugoslavism is not only complex and provocative, but currently topical as well. It is striking that even today, more than fifty-five years after the creation of the Yugoslav state, we do not have a modern and comprehensive study of the origins and development of the Yugoslav idea and, consequently, of the Yugoslav movement in the past. Inter-war Yugoslav historiography usually approached the problem from the "unitaristic" viewpoint, which corresponded to the political necessities of the time.1 As a reaction to this. post-war Yugoslav historiography espoused the other extreme: a stress on the national histories of the various Yugoslav peoples, to the detriment of the Yugoslav entity.2 When we attempt to study the development of Yugoslavism in the past, it strikes me as necessary to find the answers to three general questions: 1. What caused the origin of the Yugoslav idea? 2. What were the features of its development? 3. What were the internal and external obstacles the Yugoslav movement had to confront?

Medical Imaging

2013 ◽  
pp. 634-712 ◽  
Author(s):  
Ge Wang ◽  
Alex Cong ◽  
Hao Gao ◽  
Jie Zhang ◽  
Victor J. Weir ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Biomedical Engineering ◽  
Medical Physics ◽  
Physics Students ◽  
The Past ◽  
Interdisciplinary Field ◽  
Imaging Theory ◽  
Upper Level ◽  
Indispensable Tool ◽  
Comprehensive Study

Medical imaging is both an indispensable tool and a highly interdisciplinary field. Over the past decades, progress in medical imaging theory and technology has dramatically accelerated. This chapter provides a comprehensive study of the fundamental and advanced principles behind each of the major imaging modalities. It also presents topics related to the vision of the future of each modality. The chapter is intended for upper level or graduate biomedical engineering/bioengineering/medical physics students, researchers, and faculty.

scholarly journals Estonian traces in the tree of life concept and in the language family tree theory

2012 ◽  
Vol 3 (1) ◽  
pp. 297-326
Author(s):  
Urmas Sutrop
Keyword(s):  
Charles Darwin ◽  
Tree Of Life ◽  
Family Tree ◽  
Language Family ◽  
Animal Life ◽  
Tree Model ◽  
Tree Models

In this paper the tree model – a well-formed tree is shortly described. After that the language family tree model by August Schleicher is treated and compared with the Charles Darwin’s tree of life diagram and metaphor. The development of the idea of the linguistic trees and the tree of life is considered historically. Earlier models – scala naturae – and tree models, both well-formed and not-well-formed are introduced. Special attention is paid to the scholars connected to Estonia who developed the idea of tree models: Georg Stiernhielm was the first who pictured a language tree already in 1671; Karl Eduard Eichwald published an early tree of animal life in 1829; and Karl Ernst von Baer influenced the tree of  life models and diagrams of Charles Darwin.

Sign in / Sign up

Export Citation Format

Share Document