จำนวน Repository ( 36 )
การวิจัยปัญหาในงานหล่อและการพัฒนาแนวทางแก้ไขปัญหาในงานหล่อเครื่องประดับสมัยใหม่
Thailand’s gem and jewelry industry is widely considered one of the greatest potential markets in the world. One of the important processes is producing the body jewellery or casting. The lost-wax castingtechnique is a popular technique used widely. However it can also be a source of many defects such as porosity tarnishing incomplete form filling and water stain. There is not finding causes of problems affecting the cost of production labor energy and time increased. This research aims to study the production problems and deficiencies of work piece in the actual work from10 casting industriesto identifying and preventing all these problems. This study will be helpful to entrepreneurs gems and jewelry industry to use as guidelines to prevent defects reduce waste reduce production costs and improve the casting process for the piece even more quality. The study found that most of the production process is the main the machinery / equipment and material problems the problem of secondary respectively by this process the main problem is the casting and foundry molds the injection and the candles prototype and mold making rubber the order is a minor respectively work piece for defects in castings are very common a flaw was found in the specimens I have a 6 specimen defects found in wax and defects found in rubber molds and prototypes the defect occurs in each style be caused by a wide variety of cases. Problems encountered in this study the most hole of the shrinkage problem problem of casting porosity the hole of the bubble the cracking problem the cast is not full the problem is the ceiling.
ตัวแบบการพยากรณ์ความต้องการเหล็กภายใต้ความไม่แน่นอนโดยวิธีเบย์
The objective of this research is to propose a forecasting model for uncertain demand index data of steel. The forecasting model proposed by Yelland (2010) was modified by adjusting the prior distributions of some parameters in the model in order that it is suitable for the demand of steel in Thailand. The algorithms for model fitting were written in OpenBUGS. The proposed model was compared to a classical exponential smoothing model. The research found that the forecast errors from the proposed forecasting model were minimum.
Forecasting agricultural Products Prices by Exponential Smoothing
The objective of this study is to compare three forecasting methods on three agricultural products consisting of fresh whole chicken (include bone no entrails) red meat pork hip section and Jasmine rice. These methods are Simple Exponential Smoothing method Holt’s method and Winter’s method. Data are colleced for a period of 60 months from January 2007 to December 2011. The most suitable forecasting method are the one that shows no residual autocorrelation and gives the lowest MSE MAPE. The results show that Simple Exponential Smoothing method is the most suitable method on three agricultural products due to this method reveals no residual autocorrelation and displays the lowest MSE MAPE.
Forecasting model for the export quantity of concentrated latex
The objective of this research is to construct the appropriate forecasting model for the export quantity of concentrated latex by the three time series analysis methods which are Box-Jenkins method Winters’ multiplicative exponential smoothing method and combined forecasting method. Time series data from the website of Office of Agricultural Economics during January 1998 to February 2014 (194 values) are used and divided into two series. The first 182 values from January 1998 until February 2013 for the models prediction and the last 12 values from March 2013 until February 2014 for comparison the performance of forecasting models via the criterion of the lowest root mean squared error and the criterion of the highest correlation coefficient between existing values and forecasted values. Research findings indicated that for all forecasting methods that have been studied the most powerful method is the combined forecasting and the forecasting model is where and represent the single forecasts at time t from Box-Jenkins method and Winters’ multiplicative exponential smoothing method respectively.
Comparison of statistical techniques for forecasting The Stock Exchange of Thailand index
The purpose of this study is to compare four forecasting methods on SET Index SET 50 Index and SET 100 index. These methods are Simple Exponential Smoothing Holt’s Method Box-Jenkins Method and Regression Analysis. Two sets of Index data were used in this study. The first one used as a training set was collected at the end of each day from January 2 2008 to September 30 2011. The other one used as a testing set was collected at the end of each day from October 3 2011 to October 14 2011. The diagnostic check was used to test each method. The MAE MSE and MAPE from each method shows that Box-Jenkins is more appropriate to the forecasting of SET Index SET 50 Index and SET 100 Index because its MAE MSE and MAPE are fairly low and have no autocorrelations. This leads to the conclusion that the appropriate models for forecasting of SET Index SET 50 Index and SET 100 Index are ARIMA (212) ARIMA (213) and ARIMA (213) respectively. The most stock market indices are correlated to SET Index SET 50 Index and SET 100 Index is Composite Index of Indonesia