Akinori Okada

Akinori Okada
Tama University

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83
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Publications

Publications (83)
Article
Full-text available
What is known and objective: In our previous studies, we developed a cross-resistance rate (CRR) correlation diagram (CRR diagram) that visually captures the magnitude of CRRs between antimicrobials using scatter plots. We used asymmetric multidimensional scaling (MDS) to transform cross-resistance similarities between antimicrobials into a 2-dime...
Chapter
Models and methods of cluster analysis for asymmetric data are presented by considering two main classes: hierarchical and non-hierarchical methods. They are presented and applied to the same small illustrative data set which allows to highlight their different features and capabilities by using, when appropriate, graphical representations of the r...
Chapter
The properties of the decomposition of a square data matrix in its symmetric and skew-symmetric components are firstly presented and discussed. The orthogonal breakdown of the sum of squares of the proximities characterizing the decomposition is emphasized. Afterwards, an overview of models and methods proposed to represent, separately or jointly,...
Chapter
After a brief recall to the main aspects of the graphical representation of a rectangular matrix, two classes of methods to represent proximity matrices are reviewed: bilinear and distance-like methods. The main steps for the bilinear model estimation are presented by studying the properties of the Singular Value Decomposition of a proximity matrix...
Chapter
The present chapter deals with the types of data which are more complicated than those dealt with in previous chapters. Chapters 1 through 4 deal with one data matrix. They are classified into two kinds; one is a square matrix of objects x objects which represents relationships among a set of objects, and the other is a rectangular matrix of object...
Chapter
Some researchers noticed that proximities of three objects are useful to disclose relationships among objects. Sometimes it is not easy to obtain one-mode three-way proximities in contrast to obtain one-mode two-way proximities. Hence, a procedure to assemble one-mode three-way proximities from one-mode two-way proximities is introduced. And a meth...
Book
This book provides an accessible introduction and practical guidelines to apply asymmetric multidimensional scaling, cluster analysis, and related methods to asymmetric one-mode two-way and three-way asymmetric data. A major objective of this book is to present to applied researchers a set of methods and algorithms for graphical representation and...
Book
This edited volume focuses on the latest developments in classification and data science and covers a wide range of topics in the context of data analysis and related areas, e.g. the analysis of complex data, analysis of qualitative data, methods for high-dimensional data, dimensionality reduction, data visualization, multivariate statistical metho...
Chapter
Asymmetric multidimensional scaling is extended to represent differences among consumers in brand switching. The asymmetric multidimensional scaling, based on the singular value decomposition, represents asymmetric relationships among brands in the brand switching by introducing the outward tendency which corresponds to the left singular vector and...
Article
Asymmetric pairwise relationships are frequently observed in experimental and non-experimental studies. They can be analysed with different aims and approaches. A brief review of models and methods of multidimensional scaling and cluster analysis able to deal with asymmetric proximities is provided taking a ‘data-analytic’ approach and emphasizing...
Conference Paper
The subjective similarity among ten occupational categories is analyzed by the asymmetric multidimensional scaling based on singular value decomposition. The similarity among occupational categories is obtained by a procedure where the similarity from occupational categories j to k is judged by respondents engaged in occupational category j, and th...
Chapter
A procedure of cluster analysis to deal with asymmetric similarities is introduced, where the similarity from one object to the other object is not necessarily equal to the similarity from the latter to the former. The procedure analyzes one-mode two-way asymmetric similarities among objects to classify objects into clusters. Each cluster consists...
Article
The multi-layer cluster analysis specifies a hierarchical structure which consists of layers specified in advance, where each layer has clusters, and allocates brands to one of the clusters at each layer which minimizes a badness of fit measure based on the sum of squares of deviations in each cluster. The multi-layer cluster analysis is evaluated...
Chapter
Recently, several major advances in models of asymmetric proximity data analysis have occurred. These models usually do not deal with the relationships among three or more objects, but instead, those between two objects. However, there exist some approaches for analyzing one-mode three-way asymmetric proximity data that represent triadic relationsh...
Chapter
Brand switching data among eight soft drink brands were analyzed. The data are represented by an 8 × 8 brand switching matrix. The brand switching matrix is inevitably asymmetric, because the relationship from brand j to brand k is not necessarily equal to the relationship from brand k to brand j. The brand switching matrix was analyzed by asymmetr...
Chapter
Brand switching data among potato snacks are analyzed to evaluate a new brand. The brand switching matrix among existing brands is analyzed by asymmetric multidimensional scaling. The analysis shows the outward and the inward tendencies of existing brands, which tell the strength of switching from the corresponding brand to the other brands and the...
Book
This volume focuses on innovative approaches and recent developments in clustering, analysis of data and models, and applications: The first part of the book covers a broad range of innovations in the area of clustering, from algorithmic innovations for graph clustering to new visualization and evaluation techniques. The second part addresses new d...
Article
Sixteen Ss analyzed differences among eight kinds of type styles by means of a nonmetric multidimensional scaling procedure. This procedure is a means of explaining individual differences in perceptual structure and gives us a perceptual structure for each of the Ss as well as for a configuration of Ss. Ss discriminated differences in the color den...
Article
Cluster analysis can be divided into two categories; hierarchical and nonhierarchical cluster analyses. In the present study, a method of cluster analysis which does not utilize hierarchical nor non-hierarchical procedures is introduced. The present cluster analysis pre-specifies a structure having multiple layers, e.g., the species, the genus, the...
Article
Several analysis models for proximity data have been introduced.While most of them were for one-mode two-way data, some analysis models which are able to analyze one-mode three-way data have been suggested in recent years. One-mode three-way multidimensional scaling and overlapping cluster analysis models were suggested. Furthermore, several studie...
Article
An asymmetric similarity matrix among objects, for example, a brand switching matrix of consumers, can be analyzed by asymmetric multidimensional scaling. Suppose that n brands exist, and that m new brands are introduced. While the brand switching from existing to new brands can be observed, the brand switching from new to existing brands nor that...
Article
The centrality of an asymmetric social network, where relationships among actors are asymmetric, is investigated by singular value decomposition, conjoint measurement, and asymmetric multidimensional scaling. They were applied to asymmetric relationships among managers of a small firm. Two sets of outward and inward centralities were derived by sin...
Conference Paper
Full-text available
Some models have been proposed to analyze one-mode three-way data [e.g. De Rooij and Gower (J Classification 20:181-220, 2003), De Rooij and Heiser (Br J Math Stat Psychol 53:99-119, 2000)]. These models usually assume triadic symmetric relationships. Therefore, it is general to transform asymmetric data into symmetric proximity data when one-mode...
Conference Paper
Full-text available
Car switching or car trade-in data among car categories were analyzed by a procedure of asymmetric multidimensional scaling. The procedure, which deals with one-mode two-way asymmetric similarities, has originally been introduced to derive the centrality of the asymmetric social network. In the present procedure, the similarity from a car category...
Chapter
The purpose of the present study is to introduce a procedure to derive the centrality of an asymmetric social network, where the relationships among actors are asymmetric. The procedure is based on the singular value decomposition of an asymmetric matrix of friendship relationships among actors. Two kinds of the centrality are introduced; one is th...
Chapter
In recent years, it is possible to more easily obtain multi-way data, and various analysis models for the data have been suggested by several researchers. However, only small number of studies have been done on the one-mode multi-way data analysis model. The authors suggested an overlapping cluster analysis model for one-mode three-way similarity d...
Article
In the present paper, we propose and investigate three-way scaling and clustering approaches to musical structural analysis of emotion expression. The approach is applied to the affective values of music by subjects who were interested in theater and in instrumental music as well. We expected that we would find interesting structure in the affectiv...
Article
The present paper introduces an overlapping cluster analysis model and an associated algorithm that can analyze one-mode three-way similarities. The present model is an extension of ADCLUS model, and the present algorithm is based on the MAPCLUS algorithm. In the present model, one-mode three-way similarities are represented by the sum of the numer...
Chapter
The purpose of the present study is to disclose the relationships among Japanese prefectures in the marriage by using asymmetric multidimensional scaling. The analysis was done by external multidimensional scaling where the location of each prefecture was given externally. The data consist of frequencies of the marriage between any two prefectures...
Article
When we use multidimensional scaling (MDS) to analyze a dataset in which the magnitude of the values considerably differ (vary) among objects, for example, customer purchase history data, it often occurs that the only points of objects with large values scatter well in the configuration, but the others with small values do not scatter well. It is s...
Book
This volume presents theories, models, algorithms, and applications in clustering, classification, and visualization. It also includes applications of clustering, classification, and visualization in various fields such as marketing, recommendation system, biology, sociology, and social survey. The contributions give insight into new models and con...
Conference Paper
The relationships among government officials, working in the old capital of Japan at the eighth century, were analyzed by using asymmetric multidimensional scaling. The data consist of the relationships of giving guarantee (guarantor) and being given guarantee (warrantee) relationships among 26 government officials in the years 772, 773, and 774. T...
Conference Paper
A procedure of deriving the centrality in a social network is presented. The procedure uses the characteristic values and the vectors of a matrix of friendship relationships among actors. While the centrality of an actor has been usually derived by the characteristic vector corresponding to the largest characteristic value, the present study uses n...
Chapter
Yokoyama and Okada (2005, in press) suggested a new method that rescales a brand-switching data matrix using entropy. These studies applied the rescaling method to car-switching data, and the configuration derived by Kruskal's multidimensional scaling was interpreted as the circumplex. In the present paper, we apply that rescaling method to interge...
Article
The university enrollment flow among Japanese 47 prefectures for 31 years from 1972 through 2002 was analyzed. University enrollment flow data in the present study consist of 31 tables. Each table is 47×47, the (j, k) element of the i-th table, corresponding to year i, is the number of high school graduates in prefecture j who entered into universi...
Article
Several researchers have analyzed the brand-switching matrix using multidimensional scaling models. When a brand-switching matrix is analyzed using multidimensional scaling, it is necessary to rescale the matrix because there are differences among the overall sums of the rows and columns that depend on external factors, such as market share. This s...
Conference Paper
The purpose of the present study is to introduce a model and the associated nonmetric algorithm of multidimensional scaling for analyzing one-mode two-way (object x object) asymmetric proximities. In the model each object is represented as a point in a multidimensional Euclidean space, and a point, called the dominance point, is also embedded in th...
Chapter
A joint space model and an associated nonmetric algorithm to analyze two-mode three-way asymmetric proximities (object × object × source) are presented. Each object is represented as a point and a circle (sphere, hyper sphere) in the common joint configuration which is common to all sources. Each source is represented as a point in the common joint...
Article
Relationships among managers of a firm were analyzed. Each manager responded who goes to whom for help or advice for work-related problems. Resulting responses constitute a set of matrices, each comes from a manager. Each matrix is transformed to a matrix of geodesic distances from row to column managers. The set of geodesic distance matrices was a...
Conference Paper
An external analysis of two-mode three-way (object×object×source) asymmetric multidimensional scaling is introduced, which is similar to the external analysis of INDSCAL. The present external analysis discloses the asymmetry of each object, and source differences in symmetric and in asymmetric proximity relationships among objects respectively for...
Article
A layout of a supermarket, which increases the jointly purchasing items of different categories, was developed based on purchase data of more than 14,000 customers for half a year at a supermarket. Similarities among 24 categories of items sold at the supermarket were defined, for each of 12 conditions (the age of the customers, the place they live...
Chapter
A model and an associated nonmetric algorithm of multidimensional scaling (MDS) for analyzing two-mode three-way (object×object×source) asymmetric proximities are introduced. The model and the algorithm of the present two-mode three-way asymmetric MDS were extended from those of Okada and Imaizumi (1997) which can represent differences of symmetric...
Chapter
A procedure for analyzing social network data is introduced. The procedure can analyze social networkdata which are (a) not binary but discrete or continuously valued, and (b) asymmetric. The procedure utilizes the additive conjoint measurement by regarding rows and columnsof a social network data matrix as two different attributes, and the (j, k)...
Article
An overview of studies is presented which utilize cluster analysis and MDS (MultiDimensional Scaling) in sociology. Before focusing our attention onto studies in sociology, questionable ways of applying these two procedures are discussed which can be seen not only in studies in sociology but also commonly in many other areas. Then several aspects o...
Chapter
A model and an associated nonmetric algorithm for multidimensional scaling of two-mode three-way asymmetric proximities or a set of proximity matrices, where each matrix can be asymmetric, is presented. The present model is extended from that of (1997), and can represent differences among sources both in symmetric and in asymmetric proximity relati...
Article
A model and an associated nonmetric algorithm for analyzing two-mode three-way asymmetric proximities are presented. The model represents proximity relationships among objects which are common to all sources, the salience of symmetric proximity relationships along dimensions for each source, and the salience of asymmetric proximity relationships al...
Chapter
An asymmetric cluster analysis was applied to car switching data among 16 car segments. The asymmetric cluster analysis, which is based on an algorithm corresponding to the mean method, can represent asymmetric relationships among car segments on a dendrogram and can deal with non switchers of the car switching data (diagonal elements of the car sw...
Chapter
A model and an accompanying algorithm for two-mode three-way asymmetric multidimensional scaling is presented. The present model has a constraint on asymmetry, compared with the model of Okada, Imaizumi (1997) where each source has a different magnitude of asymmetry, but all sources are constrained so that the relative importance of the asymmetry a...
Chapter
Differences in assessments of one’s values on personal or private issues among different cohorts in age and sex in the Japanese society were investigated. Responses of about 2,700 people to 13 items were analyzed by multidimensional scaling. The two-dimensional configuration of items given by INDSCAL showed that one dimension represents extroverted...
Article
The attraction among a group of subjects was predicted by a procedure which had been originally introduced to predict the amount of purchase of a brand. The procedure, which is based on two multidimensional scaling methods ; INDSCAL and PREFMAP, was applied to friendship tie data among members of a group of 17 students collected once a week for 16...
Chapter
Brand-switching data among instant coffee brands were analyzed by a non-metric asymmetric multidimensional scaling (Okada and Imaizumi, 1987) to identify effects of the end-aisle display and of the flier. Two-dimensional solutions show that the end-aisle display of the brand is in general not effective to induce switching to the brand and is vulner...
Chapter
A predicting procedure based on two multidimensional scaling methods, INDSCAL and PREFMAP, was applied to scanner data on a brand of beer and its competitive brands at a supermarket. The data, collected at the supermarket during the first 13 weeks after the introduction of the brand, were analyzed by the procedure to predict the amount of purchase...
Article
An asymmetric multidimensional scaling model and an associated nonmetric algorithm to analyze two-mode three-way proximities (object × object × source) are introduced. The model consists of a common object configuration and two kinds of weights, i.e., for both symmetry and asymmetry. In the common object configuration, each object is represented by...
Chapter
An asymmetric multidimensional scaling model, which is derived by generalizing the predecessor, and the nonmetric algorithm to fit the present model to an asymmetric proximity matrix is presented. In the present model asymmetries in proximities are accounted for not only by the term related with stimuli or with dimensions but by the term related wi...
Conference Paper
Car switching data among 16 car segments was analyzed by an asymmetric multidimensional scaling. The car switching data was formed by rescaling a 16 × 16 car switching matrix whose (j, k) element represents the frequency with which any car in car segment j was traded-in for any car in car segment k. The asymmetric multidimensional scaling utilized...
Article
Nonmetric multidimensional scaling which could be applied to a square asymmetric interstimulus proximity matrix is presented. In the model each stimulus is represented as a point and a circle (sphere, hypersphere) whose center is at that point in a multidimensional Euclidean space . The radius of a circle (sphere, hypersphere) tells the skew-symmet...
Article
Two experiments found that the beneficial effect of feedback on performace was anegative function of goal progress. In Study 1, 87 female college students were given the goal to solve 70 arithmetic problems on a trial lasting 10 min. After 5-min work on the trial, the subjects received feedback on the number attempted. To the extentthat their goal...
Article
91 undergraduates set their own goal to be attained on a perceptual speed task lasting 15 min and received feedback after 7½ min of work. Ss' achievement need, as assessed through the Manifest Needs Questionnaire, significantly correlated with the goals set and total number attempted. Partial correlation between achievement need and the total numbe...
Article
Goal theory postulates that harder goals lead to higher performance than do easier goals. The present study tested the prediction, based on expectancy valence theory, that this would be true only if the payoff for succeeding at the harder goal is sufficiently greater than the alternatives to compensate for its greater difficulty. 63 undergraduates...
Article
A new method is introduced which can explain individual differences in dissimilarity judgments by N subjects. The method is based on a weighted distance model which is a generalization of DeLeeuw and Pruzansky's model to Minkowski r metric. A set of N dissimilarity matrices is analyzed nonmetrically to derive a group stimulus configuration and a su...
Article
An introduction for preparing manuscripts for the conference volume of The 72nd Annual Meeting of the Psychometric Society held on 9-13 July, 2007 is pro- vided in this paper. This paper is written in a format to be used for all manuscripts and illustrates the final appearance for workshop papers. It is very important to follow these instructions t...