Kankan Parmikanti

Stocks are an investment instrument that is in high demand and can provide large profits for investors, especially stocks from large and popular companies, such as PT Unilever Indonesia. However, the boycott action causes its share price to tend to decline and makes it difficult for investors to make investment decisions. In this research, the development of the Fuzzy Time Series Markov Chain (FTSMC) method, namely Fuzzy Time Series Markov Chain Absolute Differences K-Means Clustering (FTSMC-ADKC) and Fuzzy Time Series Markov Chain Tree Partition Method (FTSMC-TPM) is used in forecasting the stock price of PT Unilever Indonesia. Both methods have a good ability to forecast volatile time series data and do not require data distribution assumptions such as classical forecasting methods. Furthermore, the accuracy of the two methods is compared through the Mean Absolute Percentage Error (MAPE) value, resulting in FTSMC-ADKC being more accurate with a MAPE of 0.71% compared to FTSMC-TPM with a MAPE of 1.21%. By using FTSMC-ADKC, the closing price of PT Unilever Indonesia shares on March 27, 2024 is estimated to be Rp2724.46, which has decreased from the previous day.

Viscosity, also known as thickness, is the measure of a fluid's resistance to the stress it experiences, caused by cohesive forces between fluid particles. Surface tension is the force or downward pull caused by unbalanced attractive forces at the liquid interface, leading to the contraction of the liquid surface. Numerous studies have been conducted, particularly on determining the relationship between these two phenomena. However, very few studies are associated with fractional differential equations. This paper presents research results based on empirical data obtained from laboratory testing on viscosity and surface tension and explores their interrelationship. Through scatter plot data and regression of logarithmic functions, the obtained function is claimed as a solution to a first-order linear differential equation, with the graph of its solution matching the actual data. Subsequently, this differential equation will be generalized into a fractional differential equation with guaranteed existence and uniqueness of solutions. The method used to find solutions is the Adomian-Laplace Decomposition, and the result is that the graph of the solution function coincides with the graph of the exact solution. This indicates that the relationship between viscosity and surface tension can be described using a solution derived from a fractional differential equation model.

Every university graduate certainly expects to obtain the desired job as soon as possible. But in reality, because of high competitiveness in job markets many graduates have long waiting time to get a job. Survival analysis can be used to analyse the length of waiting time to obtain the first job. Thus, the objectives of this research are to get Cox Proportional Hazard model parameter on the length of waiting time of the graduate of Faculty of Social and Political Sciences Syarif Hidayatullah State Islamic University Jakarta to obtain the first job based on Maximum Likelihood Estimation principle and to explain factors influencing the graduate’s length of waiting time to obtain the first job by analysing the variable of gender, GPA, and study program. Data used in this research are from document of the faculty. The research found Cox Proportional Hazard model parameter on the graduate’s length of waiting time to obtain the first job and its significant influential factors, namely GPA and study program.

Rice is a primary food requirement for Indonesian people. Food processing must be managed well by companies capable of running an effective and efficient operation to facilitate the fulfillment of food needs. PT. Duta Hadir Sejahtera is one of the reputable rice companies in Kuningan. The number of production for the upcoming period will use Winters methods. The main priority rice selection will be done using Activity Based Costing (ABC) Method while the optimum purchase level and the total cost supply will be fixed using Economic Order Quantity (EOQ) Double Price method.There are two types of rice the produced, i.e. medium rice and premium rice. Using Winters method, the resulting medium rice forecasting is 146371643,5 kg each year and premium rice forecasting is 140007919,7 kg each yeas. The main priority, which is determined by using ABC Method, is premium rice with the need expectationfor a period 140007919,7 kg. By applying EOQ Double Price Break Method, it obtained the optimum purchase level for premium rice 1.500.000 kg with the price per kg Rp8.800 and the incurred total cost per year Rp1.234.965.345.154,84.   Keywords: Brown Method, Winters Method, Activity Based Costing and Economic Order Quantity (EOQ) Double Price Break Method.