scholarly journals The Choice of Initial Configurations in Multidimensional Scaling: Local Minima, Fit, and Interpretability

2017 ◽  
Vol 46 (2) ◽  
pp. 19-32 ◽  
Author(s):  
Ingwer Borg ◽  
Patrick Mair
Keyword(s):  
Multidimensional Scaling ◽  
Simulation Study ◽  
Optimal Solution ◽  
Model Fit ◽  
Local Minima ◽  
Excellent Model ◽  
Different Types ◽  
The One

Multidimensional scaling (MDS) algorithms can easily end up in local minima, depending on the starting configuration. This is particularly true for 2-dimensional ordinal MDS. A simulation study shows that there can be many local minima that all have an excellent model fit (i.e., small Stress) even if they do not recover a known latent configuration very well, and even if they differ substantially among each other. MDS programs give the user only one supposedly Stress-optimal solution. We here present a procedure for analyzing all MDS solutions resulting from using a variety of different starting configurations. The solutions are compared in terms of fit and configurational similarity. This allows the MDS user to identify different types of solutions with acceptable Stress, if they exist, and then pick the one that is best interpretable.

Quantifying Randomness Versus Consensus in Wine Quality Ratings

2014 ◽  
Vol 9 (2) ◽  
pp. 202-213 ◽  
Author(s):  
Jing Cao
Keyword(s):  
Data Analysis ◽  
Simulation Study ◽  
Mixed Model ◽  
Model Fit ◽  
Direct Measure ◽  
Wine Quality ◽  
Excellent Model ◽  
Quality Ratings ◽  
Jel Classifications ◽  
Direct Quantification

AbstractThere has been ongoing interest in studying wine judges' performance in evaluating wines. Most of the studies have reached a similar conclusion: a significant lack of consensus exists in wine quality ratings. However, a few studies, to the author's knowledge, have provided direct quantification of how much consensus (as opposed to randomness) exists in wine ratings. In this paper, a permutation-based mixed model is proposed to quantify randomness versus consensus in wine ratings. Specifically, wine ratings under the condition of randomness are generated with a permutation method, and wine ratings under the condition of consensus can be produced by sorting the ratings for each judge. Then the observed wine ratings are modeled as a mixture of ratings under randomness and ratings under consensus. This study shows that the model can provide excellent model fit, which indicates that wine ratings, indeed, consist of a mixture of randomness and consensus. A direct measure is easily computed to quantify randomness versus consensus in wine ratings. The method is demonstrated with data analysis from a major wine competition and a simulation study. (JEL Classifications: C10, C13, C15)

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

scholarly journals Visualizing Profiles of Large Datasets of Weighted and Mixed Data

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 891
Author(s):  
Aurea Grané ◽  
Alpha A. Sow-Barry
Keyword(s):  
Multidimensional Scaling ◽  
Random Sample ◽  
Simulation Study ◽  
Clustering Algorithm ◽  
Computational Cost ◽  
Interpolation Formula ◽  
Large Datasets ◽  
Mixed Data ◽  
Multivariate Techniques ◽  
High Computational Cost

This work provides a procedure with which to construct and visualize profiles, i.e., groups of individuals with similar characteristics, for weighted and mixed data by combining two classical multivariate techniques, multidimensional scaling (MDS) and the k-prototypes clustering algorithm. The well-known drawback of classical MDS in large datasets is circumvented by selecting a small random sample of the dataset, whose individuals are clustered by means of an adapted version of the k-prototypes algorithm and mapped via classical MDS. Gower’s interpolation formula is used to project remaining individuals onto the previous configuration. In all the process, Gower’s distance is used to measure the proximity between individuals. The methodology is illustrated on a real dataset, obtained from the Survey of Health, Ageing and Retirement in Europe (SHARE), which was carried out in 19 countries and represents over 124 million aged individuals in Europe. The performance of the method was evaluated through a simulation study, whose results point out that the new proposal solves the high computational cost of the classical MDS with low error.

scholarly journals A Bird’s-Eye View of Cell Sources for Cell-Based Therapies in Blood Cancers

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1333
Author(s):  
Benjamin Motais ◽  
Sandra Charvátová ◽  
Matouš Hrdinka ◽  
Michal Šimíček ◽  
Tomáš Jelínek ◽  
...  
Keyword(s):  
Hematological Malignancies ◽  
Antigen Receptors ◽  
Chimeric Antigen Receptors ◽  
Blood Cancer ◽  
Cell Based Therapy ◽  
Cell Source ◽  
Different Types ◽  
Cell Sources ◽  
The One ◽  
Initial Results

Hematological malignancies comprise over a hundred different types of cancers and account for around 6.5% of all cancers. Despite the significant improvements in diagnosis and treatment, many of those cancers remain incurable. In recent years, cancer cell-based therapy has become a promising approach to treat those incurable hematological malignancies with striking results in different clinical trials. The most investigated, and the one that has advanced the most, is the cell-based therapy with T lymphocytes modified with chimeric antigen receptors. Those promising initial results prepared the ground to explore other cell-based therapies to treat patients with blood cancer. In this review, we want to provide an overview of the different types of cell-based therapies in blood cancer, describing them according to the cell source.

How Universal Is a Construct of Loneliness? Measurement Invariance of the UCLA Loneliness Scale in Indonesia, Germany, and the United States

Assessment ◽  
2021 ◽  
pp. 107319112110345
Author(s):  
Joevarian Hudiyana ◽  
Tania M. Lincoln ◽  
Steffi Hartanto ◽  
Muhammad A. Shadiqi ◽  
Mirra N. Milla ◽  
...  
Keyword(s):  
United States ◽  
Measurement Invariance ◽  
Social Isolation ◽  
Total Sample ◽  
The United States ◽  
Cross Cultural ◽  
Model Fit ◽  
Short Version ◽  
Loneliness Scale ◽  
The One

The UCLA Loneliness Scale (ULS-20) and its short version (ULS-8) are widely used to measure loneliness. However, the question remains whether or not previous studies using the scale to measure loneliness are measuring the construct equally across countries. The present study examined the measurement invariance (MI) of both scales in Germany, Indonesia, and the United States ( N = 2350). The one-, two-, and three-factor structure of the ULS-20 did not meet the model fit cut-off criteria in the total sample. The ULS-8 met the model fit cut-off criteria and has configural, but not metric invariance because two items unrelated to social isolation were not MI. The final six items (ULS-6) exclusively related to social isolation had complete MI. Participants from the United States scored highest in the ULS-6, followed by participants from Germany and then Indonesia. We conclude that the ULS-6 is an appropriate measure for cross-cultural studies on loneliness.

Plausibility and Aesthetic Interpretation

1977 ◽  
Vol 7 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Denis Dutton
Keyword(s):  
Scientific Inquiry ◽  
The Other ◽  
Inquiry Science ◽  
Works Of Art ◽  
Different Types ◽  
Logical Structures ◽  
The One

If a catalogue were made of terms commonly used to affirm the adequacy of critical interpretations of works of art, one word certain to be included would be “plausible.” Yet this term is one which has received precious little attention in the literature of aesthetics. This is odd, inasmuch as I find the notion of plausibility central to an understanding of the nature of criticism. “Plausible” is a perplexing term because it can have radically different meanings depending on the circumstances of its employment. ln the following discussion, I will make some observations about the logic of this concept in connection with its uses in two rather different contexts: the context of scientific inquiry on the one hand, and that of aesthetic interpretation on the other. In distinguishing separate senses of “plausible,” I shall provide reason to resist the temptation to imagine that because logical aspects of two different types of inquiry—science and criticism—happen to be designated by the same term, they may to that extent be considered to have similar logical structures.

Fluid turbulence simulations of divertor heat load for ITER hybrid scenario using BOUT++

2021 ◽  
Author(s):  
Xueyun Wang ◽  
Xueqiao Xu ◽  
Philip B Snyder ◽  
Zeyu Li
Keyword(s):  
Heat Flux ◽  
Steady State ◽  
Energy Loss ◽  
Heat Load ◽  
Type I ◽  
Fluid Turbulence ◽  
Drift Model ◽  
Steady State Operation ◽  
Different Types ◽  
The One

Abstract The BOUT++ six-field turbulence code is used to simulate the ITER 11.5MA hybrid scenario and a brief comparison is made among ITER baseline, hybrid and steady-state operation (SSO) scenarios. Peeling-ballooning instabilities with different toroidal mode numbers dominate in different scenarios and consequently yield different types of ELMs. The energy loss fractions (ΔWped/Wped) caused by unmitigated ELMs in the baseline and hybrid scenarios are large (~2%) while the one in the SSO scenario is dramatically smaller (~1%), which are consistent with the features of type-I ELMs and grassy ELMs respectively. The intra ELM divertor heat flux width in the three scenarios given by the simulations is larger than the estimations for inter ELM phase based on Goldston’s heuristic drift model. The toroidal gap edge melting limit of tungsten monoblocks of divertor targets imposes constraints on ELM energy loss, giving that the ELM energy loss fraction should be smaller than 0.4%, 1.0%, and 1.2% for ITER baseline, hybrid and SSO scenarios, correspondingly. The simulation shows that only the SSO scenario with grassy ELMs may satisfy the constraint.

scholarly journals Evaluation of a Handheld Gluten Detection Device

2018 ◽  
Vol 81 (10) ◽  
pp. 1723-1728 ◽  
Author(s):  
STEVE L. TAYLOR ◽  
JULIE A. NORDLEE ◽  
SHYAMALI JAYASENA ◽  
JOSEPH L. BAUMERT
Keyword(s):  
Ice Cream ◽  
Weight Basis ◽  
Processed Foods ◽  
Gluten Free ◽  
Specific Enzyme ◽  
Different Types ◽  
Food Matrices ◽  
The One ◽  
Addition Level ◽  
Positive Results

ABSTRACT A portable, handheld gluten detection device, the Nima sensor, is now available for consumers wishing to determine if gluten is present in food. By U.S. regulation, gluten-free foods should contain <20 ppm of gluten. Thirteen gluten-free foods (muffins, three different types of bread, three different types of pasta, puffed corn snack, ice cream, meatballs, vinegar and oil salad dressing, oatmeal, and dark chocolate) were prepared; each food was spiked on a weight to weight basis with gluten levels of 0, 5, 10, 20, 30, 40, and 100 ppm before processing or preparation. Unprocessed and processed foods were tested with the handheld gluten sensor and by two gluten-specific enzyme-linked immunosorbent assays (ELISAs) on the basis of the R5 and G12 monoclonal antibodies, respectively. The portable gluten detection device detected gluten in all food types at the 30-ppm addition level, failing to detect gluten in only 5 (6.4%) of 78 subsamples. At the 20-ppm addition level, the portable gluten detection device failed to detect gluten in one type of pasta but detected gluten residues in 63 (87.5%) of 72 other subsamples. The device was able to detect gluten at the 10-ppm addition level in 9 of the 13 food matrices (41 of 54 subsamples, 75.9%) but not in the three types of pasta and the puffed corn snack. The gluten-sensing device did not perform reliably at the 5-ppm addition level in 11 of 13 food matrices (exceptions: ice cream and muffins). In contrast, the ELISA methods were highly reliable at gluten addition levels of ≥10 ppm in all food matrices. The portable gluten detection device yielded a low percentage of false-positive results (4 of 111, 3.6%) in these food matrices. Thus, this handheld portable gluten sensor performed reliably in the detection of gluten in foods having ≥20 ppm of added gluten with only 18 (5.9%) of 306 failures, if results of the one type of pasta are excluded. The device worked with greater reliability as the gluten levels in the foods increased.

scholarly journals Automation of the one-storey underground parking space organization

2021 ◽  
Vol 284 ◽  
pp. 06012
Author(s):  
Natalia Knyazeva ◽  
Anastasia Kolosova
Keyword(s):  
Evolutionary Algorithms ◽  
Urban Area ◽  
Optimal Solution ◽  
Parking Space ◽  
Space Planning ◽  
Parking Lots ◽  
Legal Documents ◽  
Space Organization ◽  
Big Cities ◽  
The One

With the growing car population in big cities, the problem of its keeping in conditions of a compact urban area has happened. The organisation of parking space in a different way has resolved this issue. Underground parking was in demand in many countries even in the XX century. By the way, they are becoming more and more popular now. The design of car parking is based on legal documents, which regulate the size of car parking seats and the width of the passage inside the garage. It is expedient to use evolutionary algorithms as one of the tools of algorithmic modelling for automation of design the car parking lots and for identifying the most effective and profitable way of the car parking space planning. So, the process of looking for the most optimal solution in underground car parking designing.

scholarly journals Linear programming measures for solving the problem of a linear division of convex multiplayers.

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Sarmad H. Ali ◽  
Osamah A. Ali ◽  
Samir C. Ajmi
Keyword(s):  
Machine Learning ◽  
Linear Programming ◽  
Optimal Solution ◽  
Optimal Method ◽  
Linear Separation ◽  
Different Types ◽  
Simplex Methods

In this research, we are trying to solve Simplex methods which are used for successively improving solution and finding the optimal solution, by using different types of methods Linear, the concept of linear separation is widely used in the study of machine learning, through this study we will find the optimal method to solve by comparing the time consumed by both Quadric and Fisher methods.

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