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Abstract

The purpose of this article is to identify the relationship between the declared activities in line with corporate social responsibility and the implementation of diversity management concepts. The paper presents the essence of corporate social responsibility as an element of company strategy, and the importance of the concept of managing diversity of employees in building an organizational culture based on mutual respect and a sense of security of employees, and thus increasing the efficiency and innovation of the company, by recognizing the individual characteristics of the people employed. An in-depth interview method was used, conducted on the basis of a non-standardized interview questionnaire with HR directors of domestic companies. The obtained empirical material was presented as a case study.

Abstract

Data have shapes, and human intelligence and perception have to classify the forms of data to understand and interpret them. This article uses a sliding window technique and the main aim is to answer two questions. Is there an opportunity window in time series of stock exchange index? The second question is how to find a way to use the opportunity window if there is one. The authors defined the term opportunity window as a window that is generated in the sliding window technique and can be used for forecasting. In analysis, the study determined the different frequencies and explained how to evaluate opportunity windows embedded using time series data for the S&P 500, the DJIA, and the Russell 2000 indices. As a result, for the S&P 500 the last days of the patterns 0111, 1100, 0011; for the DJIA the last days of the patterns 0101, 1001, 0011; and finally for the Russell 2000, the last days of the patterns 0100, 1001, 1100 are opportunity windows for prediction.

Abstract

The main purpose of the paper is an expert assessment of the relationship existing between selected indicators carried out using a relatively new tool in economic sciences: Fuzzy Cognitive Maps. The effect of its application is a graphical presentation of the relationship between the factors identified as the key ones. In the paper 23 indicators, describing four selected goals in the Strategy for Sustainable Development, 2030 Agenda were selected. It is assumed that the sustainable development goals should be related but according to the experts opinion this only applies to some indicators. This kind of relationships can be certainly identified in the case of the goals describing social and economic development, but often also economic and environmental development. However, the research results presented in the paper do not always confirm the existence of connections between individual indicators selected for the description of the goals of sustainable development. The paper tries to explain this problem.

Abstract

The paper deals with an evaluation of the quality of services provided by healthcare organizations. First, an index representing a patient’s health condition is described, then its changes before and after being treated by a given entity are employed as a criterion to assess the operations of this entity. The index of a patient’s health condition is based on the theory of survival analysis, while a model of random effects is used to determine the quality of services based on health value added.

Abstract

This paper presents a proposition to utilize flexible neural network architecture called Deep Hybrid Collaborative Filtering with Content (DHCF) as a product recommendation engine. Its main goal is to provide better shopping suggestions for customers on the e-commerce platform. The system was tested on 2018 Amazon Reviews Dataset, using repeated cross validation and compared with other approaches: collaborative filtering (CF) and deep collaborative filtering (DCF) in terms of mean squared error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE). DCF and DHCF were proved to be significantly better than the CF. DHCF proved to be better than DCF in terms of MAE and MAPE, it also scored the best on separate test data. The significance of the differences was checked by means of a Friedman test, followed by post-hoc comparisons to control p-value. The experiment shows that DHCF can outperform other approaches considered in the study, with more robust scores.

Abstract

The quarterly unemployment rate from the Labour Force Survey covering Poland’s data from the first quarter 2005 to the third quarter 2019 was investigated. The issue was to reveal its stochastic structure as a trend, seasonality and disturbance and to make a prognosis. The analysed data comes from a survey based on rotational design, so the problem of possibly autocorrelated survey errors was taken into consideration. Following Harvey (2000), Pfeffermann, Feder, and Signorelli (1997), Yu and Mantel (1997) and Bell and Carolan (1998) it seemed to be of great importance to include the proper autocorrelation structure of the errors into a statistical treatment. It appeared that for Polish unemployment data that structure was not as it could have been expected. After the model was fitted to the data, a conclusion about the specificity of the unemployment rate with respect to gender was drawn. Unemployment forecast until 2020:Q4 is provided.

Abstract

The problem of small area prediction is considered under a Linear Mixed Model. The article presents a proposal of an empirical best linear unbiased predictor under a model with two correlated random effects. The main aim of the simulation analyses is a study of an influence of the occurrence of a correlation between random effects on properties of the predictor. In the article, an increase of the accuracy due to the correlation between random effects and an influence of model misspecification in cases of the lack of correlation between random effects are analyzed. The problem of the estimation of the Mean Squared Error of the proposed predictor is also considered. The Monte Carlo simulation analyses and the application were prepared in R language.

Abstract

The paper presents a method of detecting atypical observations in time series with or without seasonal fluctuations. Unlike classical methods of identifying outliers and influential observations, its essence consists in examining the impact of individual observations both on the fitted values of the model and the forecasts. The exemplification of theoretical considerations is the empirical example of modelling and forecasting daily sales of liquid fuels at X gas station in the period 2012-2014. As a predictor, a classic time series model was used, in which 7-day and 12-month cycle seasonality was described using dummy variables. The data for the period from 01.01.2012 to 30.06.2014 were for the estimation period and the second half of 2014 which was the period of empirical verification of forecasts. The obtained results were compared with other classical methods used to identify influential observations and outliers, i.e. standardized residuals, Cook distances and DFFIT. The calculations were carried out in the R environment and the Statistica package.