Science and Technology Nakhon Sawan Rajabhat University Journal

Stock Price Forecasting using SARIMA Time Series

Salman Saleng — 2026-04-16

This article presents stock price forecasting using SARIMA time series analysis, which is suitable for seasonal data. The study utilizes daily closing prices of CP All Public Company Limited (CPALL) stock from 2014 to 2024. The analysis process includes data collection, data formatting and cleaning, exploratory data analysis, and the creation and testing of the SARIMA model using Python on Google Colab. The research findings indicate that the SARIMA(0,1,1)(0,0,2,12) model can effectively forecast stock price trends with an RMSE of 6.226 baht, which represents a low average deviation between forecasted and actual prices. This reflects the accuracy of the model in capturing stock price trends. These research findings can effectively support long-term investment decision-making.

Diurnal Variations and Morphology of PM2.5 During Haze Period in Mueang Nakhon Sawan District, Nakhon Sawan Province

Anuwat Sangon — 2026-04-23

This research investigates the diurnal variations and morphology of PM2.5 during the haze period in Mueang Nakhon Sawan District, Nakhon Sawan Province. PM2.5 concentration and meteorological data were retrieved from the Pollution Control Department (PCD) database and the Meteostat website for the period of March–April 2025. Concurrently, PM2.5 samples were collected for morphological and elemental composition analysis via scanning electron microscopy. The results indicated that PM2.5 levels exhibited diurnal variations corresponding to agricultural residue burning and heavy traffic during rush hours. Correlation analysis with meteorological data suggested that atmospheric stability significantly influenced the accumulation and dispersion of PM2.5. Morphological and elemental analysis identified biomass burning, fossil fuel combustion, and long-range transport as the primary sources of PM2.5. Furthermore, two carcinogenic heavy metals—mercury (Hg) and chromium (Cr)—were detected within the PM2.5 samples.

Analysis of the Angular Velocity of a Spinner using Smartphone-Based Measurement

Nichawee Sangsen — 2026-04-16

Rotation is a fundamental topic in physics education at both secondary and university levels, helping students understand the concepts of torque, moment of inertia, and angular velocity. However, students often encounter difficulties in linking theoretical models with the actual behavior of systems subject to rotational damping. This article presents a study on the decrease in angular velocity of a modified spinner using a smartphone as a measuring device through its gyroscope sensor to explain the mechanism of rotational damping torque and enhance the empirical understanding of the theoretical model. The experimental results show that the angular deceleration exhibits distinct behaviors between the high and low angular velocity ranges. In the high angular velocity range, the decrease follows an exponential relationship, reflecting the influence of linear damping torque caused by air resistance and internal bearing friction. In contrast, in the low angular velocity range, the decrease is nearly linear, consistent with constant frictional torque. The analysis reveals a transition between these two damping mechanisms and suggests that this phenomenon can be effectively used as a case study to help students connect theoretical models with real experimental observations in rotational dynamics.