No abstract

To maintain the confidential data, a scheme or algorithm is needed to protect the data from many attacks. Recently, many cryptography schemes and algorithms have been introduced. One of them is the cryptography algorithm based on chaotic maps. The nature of the chaotic maps gives many advantages to the algorithm. In this paper, an algorithm to encrypt the text is purposed. The algorithm utilizes the nature of the chaotic map by using the MS map as a keystream generator. The ciphertext found by the purposed algorithm is very difficult to be cracked by the bruce-force attack and known-plaintext attack. The decryption process has been tested using 3 different secret keys (that is very similar with the secret key on the encrypted process), and resulting the decrypted text is the same with plaintext only if the input is exactly the same secret key as in encrypted process.

Fuzzy Logic is a development of Binary Logic that can be used to analyze data in research in both the exact and social fields. In this study, fuzzy logic is used to analyze data in a "Ayam Goreng Murah Rezeki" restaurant related to three linguistic attributes, each of which consists of two linguistic variables: Inventory (Little, Many), Sales (Down, Up), and Purchases (Reduced, Increased) using the Mamdani method. The purpose of the study is to provide an input value of Inventory and Sales to get a Purchase output value. The results of data analysis using a linear down graph and a linear upward graph on each linguistic variable with the Mamdani method yield results in the estimated area or range.

<p class="Default"><strong><em>Actuarial science study program is a new study program in Indonesia. Recently many universities in Indonesia have opened the study program. Currently, Indonesia needs more actuary, this is one of the reasons for the existence of the actuarial science study program in Indonesia. However, many Indonesians do not know about the actuary and actuarial science field. Besides that, most Indonesians have not realized the importance of insurance for our life. The socialization about actuary and insurance is one of the ways to introduce actuary and increase the insurance awareness to the people in Indonesia, especially in Cikarang. This event went by distributing pamphlet and giving a short explanation to the respondent about actuary, insurance, and the relationship between them.</em></strong></p>

In investing, all investors must be faced with risk that must be borne. Therefore, to determine the best strategy in investing, every investor must calculate the risk. One statistical approach that can be used to measure the risk is Value at Risk (VaR). VaR is defined as a tolerable loss with a certain level of confidence. The purpose of this research is to estimate VaR using Variance Covariance and Historical Simulation methods on banking stock portfolio consisting of three stocks for the period 11 September 2020-30 September 2021. Both methods will then be evaluated using backtesting to determine the accuracy of VaR and to obtain the best method. From the research results, if the holding period is 1 day, then the VaR calculation for banking stock portfolio using both methods can be used to estimate the risk at 99% and 95% confidence levels, except for the VaR value using the Variance Covariance method for banking stock portfolio at 95% confidence level. The results show that Variance Covariance method is the best method for 99% confidence level. As for the 95% confidence level, Historical Simulation method is the best method.