จำนวน Repository ( 34 )
การประมาณค่าความแปรปรวนของการแจกแจงพาเรโตะ : การศึกษาเชิงจำลอง
This research proposes the variance estimation method of Pareto data and to compare three variance estimation methods. Those methods are simple method the adjusted variance method with term (n - 1)/n and the adjusted variance method with term (n - 2)/n. The research was considered by the absolute of bias (|Bias|) the mean absolute errors (MAE) and the mean square errors (MSE) of variance estimator. This research used Monte Carlo Simulation method. Results of this research show that the |Bias| of simple method is the lowest for almost all conditions. We can arrange the methods as follows: the adjusted variance method with term (n - 1)/n and the adjusted variance method with term (n - 2)/n respectively. For all situations the MAE and MSE the of adjusted variance method with term (n - 2)/n is the lowest. We can arrange the methods as follows: the adjusted variance method with term (n - 1)/n and simple method respectively.
Study of Ozone Generator with Electric Fields Distribution on Water Surface
This paper proposes a study of an Ozone generator. The generator under the study is designed using the electrode with uniform field. The electrode is constructed in the plane shape with positive potential. The transformer oil is used as insulating materials to prevent discharges around the electrode discharges in the air void depends on the size the types of dielectrics and level of applied voltage. Between the electrode and the air void there is acyclic dielectric. The stainless electrode with water is used as a ground potential. The breakdown depends on the electric field intensity. It is found that there is sufficient amount of ozone due to the ionization Development and design ozone generator this research electric field intensity on the water type and this can be used as a principle to construct a new type of ozone generator.
แบบจำลองระบบควบคุมสั่งจ่ายการจ่ายไฟฟ้าแบบอัตโนมัติ
This project report proposes a Model of Command System for Automatic d by the device can be controlled automatic transmission. Using the computer Power Control. Generator as a second pass through devices various. And to analyze what is happening in the transmission line. Design and Create Model of Command System for Automatic Power Control This purpose Create Model of Command System for Automatic Power Control. In order to understand the transmission line. And cause occurring in the transmission line. Can be cut the voltage or current out of range immediately beyond the setting. Experiments will be power supply to model And connected to the load for the parameters In order to show the value of the program window That over or under the setting or not. By experiment will be test the effectiveness of the program That has performance any. From experimentation model of Command System for Automatic Power Control able to control the power supply according to demand.
กระบวนการสโตแคสติก สำหรับการวิเคราะห์ตัวแบบอนุกรมเวลา โดยประยุกต์ใช้กับข้อมูลราคาจริง และราคาในตลาดล่วงหน้าของข้าวในประเทศไทย
The objective of this research is to use a stochastic process for building a model using Bayesian parameter estimation. The model is applied to the of crash prices and future prices of rice in Thailand for 120 moths including monthly closing average price of white rice 5% non-glutinous paddy 15% and Hom Mali non-glutinous paddy 105. The data are time series data containing autocorrelation trend seasonality and outliers. The algorithms are turned into codes in OpenBugs and the performance of the model is evaluated using simulation in R. The model with a Weibull cumulative distribution function trend the model with an exponential cumulative distribution function trend and the exponential smoothing model are compared. The root mean squared error (RMSE) mean absolute percentage error (MAPE) and mean absolute error (MAE) are used as the criteria. The results show that the model with the model with an exponential cumulative distribution function trend gives smallest RMSE MAPE and MAE for the crash prices of non-glutinous paddy 15% and Hom Mali non-glutinous paddy 105 for both model fitting part and model validation part. The model with a Weibull cumulative distribution function trend gives the smallest RMSE MAPE and MAE for the closing average price of white rice 5% for both model fitting part and model validation part.
พัฒนาโลหะมีค่าชนิดทังสเตนคาร์ไบต์ผ่านการรีไซเคิลหมุนเวียนมาใช้ใหม่เพื่อผลิตชิ้นส่วนโลหะความแข็งสูง
This research was on the production of hardmetal from recovery of tungsten carbide tool scraps recycling through ball milling for 40 hours. The metal powder obtained which was of the size between 0.11-0.22 µm was composed of 96.69% of tungsten carbide (WC) 1.68% of tantalum (Ta) 1.21% of titanium (Ti) and 0.42% of niobium (Nb). When mixed with 5-15% cobalt binder metal cold isostatic press (CIP) sintered at 1450 ° C it became hardmetal work piece dimension 12.39 x 13.82 x 5.60 mm with 1410 HV hardness and 14.34 g/cm3 density. The result of S45C steel turning was tools life good. The research concluded that the hardmetal work piece produced by the developed material had suitable basic specification and would lead to the development in working in the future.