On the closure of relational models

Relational models for contingency tables are generalizations of log-linear models, allowing effects associated with arbitrary subsets of cells in a possibly incomplete table, and not necessarily containing the overall effect. In this generality, the MLEs under Poisson and multinomial sampling are not always identical. This paper deals with the theory of maximum likelihood estimation in the case when there are observed zeros in the data. A unique MLE to such data is shown to always exist in the set of pointwise limits of sequences of distributions in the original model. This set is equal to the closure of the original model with respect to the Bregman information divergence. The same variant of iterative scaling may be used to compute the MLE in the original model and in its closure

Faithfulness and learning hypergraphs from discrete distributions

The concepts of faithfulness and strong-faithfulness are important for statistical learning of graphical models. Graphs are not sufficient for describing the association structure of a discrete distribution. Hypergraphs representing hierarchical log-linear models are considered instead, and the concept of parametric (strong-) faithfulness with respect to a hypergraph is introduced. Strong-faithfulness ensures the existence of uniformly consistent parameter estimators and enables building uniformly consistent procedures for a hypergraph search. The strength of association in a discrete distribution can be quantified with various measures, leading to different concepts of strong-faithfulness. Lower and upper bounds for the proportions of distributions that do not satisfy strong-faithfulness are computed for different parameterizations and measures of association.Comment: 23 pages, 6 figure

Relational models for contingency tables

The paper considers general multiplicative models for complete and incomplete contingency tables that generalize log-linear and several other models and are entirely coordinate free. Sufficient conditions of the existence of maximum likelihood estimates under these models are given, and it is shown that the usual equivalence between multinomial and Poisson likelihoods holds if and only if an overall effect is present in the model. If such an effect is not assumed, the model becomes a curved exponential family and a related mixed parameterization is given that relies on non-homogeneous odds ratios. Several examples are presented to illustrate the properties and use of such models

Approximation to the theory of affinities to manage the problems of the groupping process

New economic and enterprise needs have increased the interest and utility of the methods of the grouping process based on the theory of uncertainty. A fuzzy grouping (clustering) process is a key phase of knowledge acquisition and reduction complexity regarding different groups of objects. Here, we considered some elements of the theory of affinities and uncertain pretopology that form a significant support tool for a fuzzy clustering process. A Galois lattice is introduced in order to provide a clearer vision of the results. We made an homogeneous grouping process of the economic regions of Russian Federation and Ukraine. The obtained results gave us a large panorama of a regional economic situation of two countries as well as the key guidelines for the decision-making. The mathematical method is very sensible to any changes the regional economy can have. We gave an alternative method of the grouping process under uncertainty

IDENTITY FOCUSED ADAPTATION OF NEWCOMERS IN ORGANIZATIONS: RESOURSE FOR PERSONNEL MANAGEMENT

The report addresses the issue of adaptation of newcomers in organizations. This problem is very important now in business and public organizations according to the problem of labor productivity, staff turnover, corporate culture etc. In spite of obvious importance of the adaptation in organization, the studies of this problem require new approaches and methods. Mechanisms are explored that help to retain the staff in organization and to create a desire to continue its activities in this organization. The research is implemented to the framework of the business-psychological approach (S Benton, N. Ivanova, theory of social identity (H. Tajfel, J.C. Turner), concepts of adaptation (T. Bazarov, N. Volkova etc.). Adaptation of newcomers is considered as a natural stage of professional and social self-determination of the individual, as overcoming the identity crisis and identity forming process. In the course of adaptation, an identity is formed that is adequate in relation to the new social roles and goals of activity. The purpose of the study: to develop the identity focused adaptation model, to test the role of this model in the work with newcomers in organization. Methodology: questionnaire (N= 109), Job Satisfaction Survey (N=15), case study in organizations. Results: The role of information and psychological support of a novice from the manager, mentor and team while including a specialist in joint activities is revealed. The directions of improving the system of adaptation of newcomers in the organization are highlighted. An identity focused adaptation model has been developed, which includes the following components: A) Preliminary information to newcomers: preparatory briefing about the company; detailed briefing about the company\u27s rules and regulations. B) Information about newcomers to colleagues: about the new employee, his workplace, the tasks of his adaptation, the appointment of a mentor. C) Communications of the mentor: checking the workplace, the initial conversation, monitoring the problems and successes, the employee\u27s initiation into the company\u27s affairs. D) Communications of the manager: aimed at reducing the uncertainty of the newcomer in the first days of work. E) Communication of newcomers: questions, feedback, ideas, doubts, wishes. Results of this research can be useful for management, counseling and coaching for development of newcomer’s identity, loyalty, and performance

Iterative Scaling in Curved Exponential Families

The paper describes a generalized iterative proportional fitting procedure that can be used for maximum likelihood estimation in a special class of the general log-linear model. The models in this class, called relational, apply to multivariate discrete sample spaces that do not necessarily have a Cartesian product structure and may not contain an overall effect. When applied to the cell probabilities, the models without the overall effect are curved exponential families and the values of the sufficient statistics are reproduced by the MLE only up to a constant of proportionality. The paper shows that Iterative Proportional Fitting, Generalized Iterative Scaling, and Improved Iterative Scaling fail to work for such models. The algorithm proposed here is based on iterated Bregman projections. As a by-product, estimates of the multiplicative parameters are also obtained. An implementation of the algorithm is available as an R-package

THE ROLE OF IDENTITY FOCUSED COMUNICATIONS IN PERSONNEL MANAGEMENT

The report addresses the issue of business communication and its role in organizations in the aspects of personnel management. We study how communication influences the retention and good performance of personnel. Communications are an integral part of the activity of organizations. Communications largely determine the effectiveness of personnel management. Well-designed communications reduce the time of problem solving and of adaptation of employees, help in conflict resolutions etc. In spite of obvious importance of the communications in organization the studies of this problem require new approaches and methods. We explore mechanisms that help to keep the staff in organization and to create a desire to continue its activities in this organization. On base of social identity approach (H. Tajfel, J.C. Turner) and business psychology approach (S Benton, N. Ivanova,) we studied the Identity Focused Communication (IFC). This type of communication realizes, through integrated work of organization, the development of cognitive, value-motivational and behavioral characteristics of social identity. IFC can be considered as a human development technology which helps employers in clear understanding of values, professional and social role and pattern of behavior in organization. On this theoretical basis and case studies method in different organizations we observed the role of IFC in the development of organizational culture for rising of personnel engagement and loyalty. Results of this research can be useful for business counseling and business management process, development of personnel identity, loyalty, and performance. The results allow us to see new aspects in communication, develop training programs and staff development, and improve internal communication. Our results can develop the understanding of the semantic core of effective communication’s strategy of organization which include corporate “picture of world” and image of the organization. We can add the knowledge of professional values and patterns of behavioral and social roles. The data obtained can be considered as a pilot to build new hypotheses and further research on a broader sample and with the use of experimental procedures