In the Gamma-semigroup generated from a semigroup, we can define some equivalence relations called the Green relation. Furthermore, we can examine the relationship between the Green relation on the Gamma-semigroup and the Green relation on it’s generating semigroup.

We are discussed operator norms on space of Dunford integral function. We show that sets of all bounded linear operator from dual space of Banach space into space of Lebesgue integral function is Banach space. Abstrak. Artikel ini membahas norma operator atas operator linear terbatas pada ruang fungsi terintegral Dunford. Himpunan semua operator linear dari ruang dual atas ruang Banach ke ruang fungsi terintegral Lebesgue merupakan ruang bernorma yang lengkap terhadap norma operator yang diberikan.

Coprime Graph is a geometric representation of a group in the form of undirectedgraph. The coprime graph of a group G, denoted by $\Gamma_G$ is a graph whose vertices are all elements of group G; and two distinct vertices a and b are adjacent if and only if $(|a|,|b|)=1$. In this paper, we study coprime graph of integers modulo n group and its subgroups. One of the results is if n is a prime number, then coprime graph of integers modulo n group is a bipartite graph.

Based on data from Badan Pusat Statistik (BPS), the number of Indonesia's population has consistently increased every year. This will cause several problems, one of them is public health. Health problems that occur cause some risks that cause losses. Therefore, one way to reduce the impact of these risks is insurance. This study analyzes how the process of forming premium prices with loading assumptions that are in accordance with existing assumptions in order to meet the criteria of equitable to the client, deliverable by the agent, and profitable to the company. This research uses a quantitative research approach. The population in this study was all Sum Insured (SI) while the sample was 1000 SI male sex. The data used in this study are secondary data that is data from an ABC insurance company in Indonesia, literature study through books, journal references, and previous research. The results of this study are the calculation of premiums by the methods used by the company more efficiently when compared with formulas in accordance with the theory. Although the price of a premium is more expensive using the company method, it is not significantly different. If using the company method, the sum insured used is the sum insured from death benefit whereas the theory is the average of claims incurred at that age. The fees charged are still fairly reasonable in accordance with the rules of setting the price of insurance premiums. In addition, the use of CSO 80 tables and Reinsurance Rates that have been adjusted to the company's interest rate of 5% in accordance with the expected cash value desired by the company.

Imbalanced data might cause some issues in problem definition level, algorithm level, and data level. Some of the methods have been developed to overcome this issue, one of state-of-the-art method is Easy Ensemble. Easy Ensemble was claimed can improve model performance to classify minority class, and overcome the deficiency of random under- sampling. In this paper we discussed the implementation of Easy Ensemble with Random Forest Classifiers to handle imbalance problem in credit scoring case. This combination method is implemented in two datasets which taken from data science competition website, finhacks.id and kaggle.com with class proportion within majority and minority is 70:30 and 94:6. The results showed that resampling with Easy Ensemble can improve Random Forest classifier performance upon minority class. Recall on minority class increased significantly after the resampling. Before resampling, the recall on minority class for the first dataset (finhacks.id) was 0.49, and increased to 0.82 after the resampling. Similar results were obtained for the second data set (kaggle.com), where the recall for the minority class was increased from just 0.14 to 0.73.

A fractional diffusion-wave equations in a fractional viscoelastic media can be constructed by using equations of motion and kinematic equations of viscoelasticmaterial in fractional order. This article concerns the fractional diffusion-wave equations in the fractional viscoelastic media for semi-infinite regions that satisfies signalling boundary value problems. Fractional derivative was used in Caputo sense. The analytical solution of the fractional diffusion-wave equation in the fractional viscoelastic media was solved by means of Laplace transform techniques in the term of Wright function for simple form solution. For general parameters, Numerical Inverse Laplace Transforms (NILT) was used to determine the solution.

A Secret sharing scheme is a method for dividing a secret into several partialinformation. The secret can be reconstructed if a certain number of partial information is collected. One of the known secret sharing schemes is the Shamir’s secret sharing scheme. It uses Lagrange interpolation (with one indeterminate) for reconstructing the secret. In this paper, we present a secret sharing scheme using multivariate polynomials with the secret reconstruction process using the multivariate interpolation formula derived by Saniee (2007). The resulted scheme can be considered as a generalization of the Shamir’s secret sharing scheme.

In this paper, it will be discussed some fixed point theorems in ultrametric spaces. By using spherically complete properties, it can be shown that there exists a unique fixed point of strictly contractive function. At the end, it will be shown there exists fixed point of strictly contracting on orbits function.

The definition of symmetric element in a ring with unity and equipped with involution can be generalized to generalized symmetric elements. But the properties of symmetric element not automatically can be generalized to generalized symmetric elements. In this paper, we discuss the property of symmetric element which can or cannot be generalized to generalized symmetric elements. Because of at least there is an element of symmetric and generalized symmetric elements which have the generalized Moore Penrose inverse, so method in this paper is by establishing a relationship between symmetric element, generalized symmetric element and generalized Moore Penrose inverse of element.

In this paper, we discuss that in the approachable functions set can be defined a complete norm. Furthermore, we obtained that all of approachable functions set is a Banach Space.

Multiple imputation is one of estimation method used to impute missing observations. This method imputes missing observation several times then it is more possible to get the right estimate than just one time imputation. In this research, the method will be applied to estimate missing observations in covariates of recurrent event data. Some multiple imputation methods will be considered including combination of the event indicator, the event times, the logarithm of event times, and the cumulative baseline hazard. To compare these methods, Monte Carlo simulation will be used based on relative bias and Mean Squared Error (MSE). The recurrent events will be modelled using Cox proportional hazard model. Furthermore, real data application will be presented.