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Sapiness–sentiment analyser

Abstract

In our ever-evolving world, the importance of social networks is bigger now than ever. The purpose of this paper is to develop a sentiment analyzer for the Hungarian language, which we can then use to analyze any text and conduct further experiments. One such experiment is an application which can interface with social networks, and run sentiment analysis on the logged-in users friends’ posts and comments, while the other experiment is the use of sentiment analysis in order to visualize the evolution of relationships between characters in a text.

Open access
On the scores and degrees in hypertournaments

Abstract

A k-hypertournament H = (V, A), where V is the vertex set and A is an arc set, is a complete k-hypergraph with each k-edge endowed with an orientation, that is, a linear arrangement of the vertices contained in the edge. In a k-hypertournament, the score si(losing score ri) of a vertex is the number of edges containing vi in which vi is not the last element(in which vi is the last element) and the total score of a vertex vi is ti = si − ri. For v ∈ V we denote dH+=aHρ(v,a) (or simply d+(v)) the degree of a vertex where, ρ(v, a) is k − i if v ∈ a ∈ A and v is the ith entry in a, otherwise zero. In this paper, we obtain necessary and sufficient conditions for a k-hypertournament to be degree regular. We use the inequalities of Holder and Chebyshev from mathematical analysis to study the score and degree structure of the k-hypertournaments.

Open access
Tripartite graphs with given degree set

Abstract

If k ≥ 1, then the global degree set of a k-partite graph G = (V 1, V 2, . . . , V k, E) is the set of the distinct degrees of the vertices of G, while if k ≥ 2, then the distributed degree set of G is the family of the k degree sets of the vertices of the parts of G. We propose algorithms to construct bipartite and tripartite graphs with prescribed global and distributed degree sets consisting from arbitrary nonnegative integers. We also present a review of the similar known results on digraphs.

Open access
Trade Credit Insurance and Asymmetric Information Problem

Abstract

The presence of different risk factors in international trade gives evidence of the necessity of support in gaps that may affect exporters’ activity. To maximize the trade volumes and in the same time to minimize the exporters’ risks the stakeholders use trade credit insurance. The paper provides analysis of conceptual background of the trade credit insurance in the world. We analyzed briefly the problems, arising in insurance markets due to asymmetric information, such as adverse selection and moral hazard. Also we discuss the main stages of development of trade credit insurance in countries worldwide. Using comparative and graphical analysis we provide a brief evaluation of the dynamics of claims and recoveries for different forms of trade credit insurance. We found that the claims related to the commercial risk for medium and long trade credits in recent years exceed the recoveries, while with the political risk the reverse trend holds. And we originally consider these findings in terms of information asymmetry in the trade credit insurance differentiated by type of risk.

Open access
Estimating the maximum rise in temperature according to climate models using abstract interpretation

Abstract

Current climate models are complex computer programs that are typically iterated time-step by time-step to predict the next set of values of the climate-related variables. Since these iterative methods are necessarily computed only for a fixed number of iterations, they are unable to answer the natural question whether there is a limit to the rise of global temperature. In order to answer that question we propose to combine climate models with software verification techniques that can find invariant conditions for the set of program variables. In particular, we apply the constraint database approach to software verification to find that the rise in global temperature is bounded according to the common Java Climate Model that implements the Wigley/Raper Upwelling-Diffusion Energy Balance Model climate model.

Open access
Financial Stability of Insurance Companies in Selected CEE Countries

Abstract

Background: Financial stability or soundness of insurance companies has gained importance over the years, especially after the financial crisis of 2008. Various stakeholders such as policy makers, regulators, the insured, etc. are interested in keeping the insurance sector stable since it contributes to overall financial stability.

Objectives: The authors explore the determinants of insurers’ soundness in selected countries in Central and Eastern Europe. The analysis covers life, non-life and composite insurers that operated in Croatia, Hungary, and Poland in the period 2013 – 2017.

Methods/Approach: A set of insurer – specific, industry – specific and macroeconomic variables are taken into consideration for having a potential influence on soundness measured by the Z-score. The variables include the size based on total assets, the share of premium ceded to reinsurance, claims growth, gross written premium growth, the premium to surplus ratio, market shares held by the five largest insurers, the share of gross written premium in the gross domestic product (GDP) and the GDP per capita growth.

Results: The findings reveal that soundness of Croatian insurers is positively influenced by the size of an insurer. Both in Hungary and Poland reinsurance plays an important factor positively affecting soundness.

Conclusions: Each of the insurance markets covered by the analysis reveals its characteristics and offers guidelines on factors influencing financial stability.

Open access
Identifying Key Fraud Indicators in the Automobile Insurance Industry Using SQL Server Analysis Services

Abstract

Customer segmentation represents a true challenge in the automobile insurance industry, as datasets are large, multidimensional, unbalanced and it also requires a unique price determination based on the risk profile of the customer. Furthermore, the price determination of an insurance policy or the validity of the compensation claim, in most cases must be an instant decision. Therefore, the purpose of this research is to identify an easily usable data mining tool that is capable to identify key automobile insurance fraud indicators, facilitating the segmentation. In addition, the methods used by the tool, should be based primarily on numerical and categorical variables, as there is no well-functioning text mining tool for Central Eastern European languages. Hence, we decided on the SQL Server Analysis Services (SSAS) tool and to compare the performance of the decision tree, neural network and Naïve Bayes methods. The results suggest that decision tree and neural network are more suitable than Naïve Bayes, however the best conclusion can be drawn if we use the decision tree and neural network together.

Open access
Economic Factors in the Process of Calculation of Annuities in Bodily Injury Compensation Claims Under Liability Insurance

Abstract

The article constitutes a legal and economic discussion of the economic factors which may and should be taken into account while calculating the benefits compensating the loss of income of the injured and of their families in case of death. The analyzed benefits are an important element of compensation of economic loss in personal injury cases where the compensation is the duty of the perpetrator (or the entity responsible for him/her) within the system based on tort liability. In light of the ubiquitous nature of TPL insurance, the payer is usually the insurance company liable under the granted guarantee. The scope of such cover results from the contract and/or legal acts. The subject calculation was based on an actuarial annuity which also takes into account the likelihood of the claimant and his/her relatives living until the subsequent periodical payments. The applied calculation is of an illustrative nature with regard to the considerations of the relevant economic assumptions made at the time of loss calculation. The discussion carried out in the article concerns the size and value of the economic factors that can be used in this model.

Open access
New results on connected dominating structures in graphs

Abstract

A set of vertices in a graph is a dominating set if every vertex not in the set is adjacent to at least one vertex in the set. A dominating structure is a subgraph induced by the dominating set. Connected domination is a type of domination where the dominating structure is connected. Clique domination is a type of domination in graphs where the dominating structure is a complete subgraph. The clique domination number of a graph G denoted by γk(G) is the minimum cardinality among all the clique dominating sets of G. We present few properties of graphs admitting dominating cliques along with bounds on clique domination number in terms of order and size of the graph. A necessary and sufficient condition for the existence of dominating clique in strong product of graphs is presented. A forbidden subgraph condition necessary to imply the existence of a connected dominating set of size four also is found.

Open access
Life tables estimation for pension system actuarial projection model with insufficient data: case of Republic of Srpska

Abstract

This article provides an upgraded model for actuarial projection of the dependency ratio of the pension fund in the Republic of Srpska. The nonexistence of complete upto-date life tables presents a huge problem of the pension system and life insurance industry modelling in the Republic of Srpska. Therefore, this article tries to encompass the problem by using the life tables of the Republic of Croatia as a starting point for adjustment of age-grouped life tables available for population of the Republic of Srpska. The actuarial projection model for the Pension and Disability Insurance Fund of the Republic of Srpska is upgraded by using these adjusted life tables and the best estimate mortality trend for mortality forecasting. The results of the Republic of Srpska pension fund dependency ratio projections obtained using a forecast of adjusted life tables are compared to the previous research on this topic which used the life tables of the Republic of Serbia for 2013 for the same model. This way we can observe the effect of life expectancy growth on pension fund’s dependency ratio estimates as one of the measures of pension fund’s sustainability.

Open access