This research is to develop a prototype of a salinity intrusion monitoring system using fuzzy logic to extract salinity values. A system is developed according to a fuzzy logic model using FAOs for appropriate agricultural water quality data considering the electrical conductivity (EC) and total dissolved solids (TDS) as indicators of the salinity value by using the Fuzzy Logic Toolbox to produce and test the generated model. Transformation of the generated models to Embedded C format using the Simulink Coder tool installed in the ARM STM32F microcontroller and a 10-fold cross-validation test was used to validate the data extraction. The Root Mean Square Error (RMSE) for the test results was 0.58175 on average. This research result indicates that the generated model is able to extract data that very closely matches the specified data.

This quantitative research aimed 1) to study operation performance of Thai Gem Businesses. 2) To study factors affecting firm performance of Thai Gem Businesses. The research was collected data by using questionnaire with 452 participants from production group of Thai Gem Businesses. The samples were collected conveniently and analyzed by frequency percentage mean standard deviation Pearson’s correlation coefficient and analysis confirmatory with Structural Equation Modeling: SEM. It was one of all statistic techniques to test for causal relationship of variables. The results found that database information management systems have positively affect strategic management and firm performance of Thai Gem Businesses with significant level 0.05. Database information management systems also have positive affect on strategic management of Thai Gem Businesses with significant level α < 0.05. Besides this research results found that database information management systems has positively direct and indirect affecting firm performance by pass strategic management with direct affect on firm performance equal to 0.346 and indirect affect by pass strategic management equal to 0.575. And total affect was equal to 0.921 with significant level. It showed that overall affect of database information management system on firm performance was more than strategic management affect to Firm Performance (0.603) with significant level 0.05. The analysis of correlation coefficient model showed that measurement between latent variables have positive correlation with significant level α < 0.05. The analysis of Structural Equation Model revealed that it wassuitable harmonize with empirical data ( χ2 / df = 1.489 CFI = 0.997 AGFI = 0.957 RMSEA = 0.08 RMR = 0.004) and consistent with the define hypothesis. The research results described the environmental of firm performance approach to strategic management by TOWS Matrix and recommendation on strategic management to solve problems on firm performance of Thai Gem Businesses in order to develop continuous firm performance for competitive advantage.

This research aimed 1) to study levels of transformational leadership innovative climate knowledge management systems innovative work behaviors and firm performances 2) to investigate causal relationship of transformational leadership innovative climate knowledge management system as well as innovative work behaviors which influenced on performances of the Medical Device Business in Thailand 3) to examine relevance of those variables along with causal relationships of the antecedents affecting performance of the Medical Device Business in Thailand to empirical data. Data were collected from 312 middle level managers in Medical Device Business in Thailand by using questionnaires as a research instrument. All of the data were analyzed using Structural Equation Model. The analysis of correlation coefficient model showed that the latent variables significantly related to one other at statistical level of 0.001. The analysis of structural equation model (SEM) revealed that the model was completely compatible with the empirical data and the hypothesis. (GFI = 0.933 CFI = 0.972 RMSEA = 0.078 RMR = 0.018) The findings also showed that transformational leadership significantly affected innovative work behaviors at statistical level of 0.001. Similarly innovative climate significantly affected innovative work behaviors at statistical level of 0.001. Likewise knowledge management system significantly affected innovative work behaviors at statistical level of 0.001. Finally innovative work behaviors significantly and directly affected the firm performance at statistical level of 0.05.

This research presents the development of ultrasonic scaler for mobile dental unit. The operation of the scaler uses a phase-locked loop circuit to generate high frequency electrical signal. Then the signal is amplified with a Darlington amplifier circuit to feed to the coil in the Hand Piece resulting in Magnetostriction. This phenomenon causes the stretching and shrinking of the magneto-strictive stack with high frequency which causes the tip of the scaling head to vibrate more than 20000 times/second. Traditional ultrasonic scaler for mobile dental unit has thermal problem of the amplifier circuit due to use of the transistors as the switching devices. When used for a period of time the scaler is necessary to stop working resulting in not much scaling per day. This research solved the problem by using MOSFETs as switching devices and adding cooling system to the amplifier circuit. The experiment was carried out using actual conditions. The experimental results show that the developed scaler has increased the number of scaling per day. In addition it will still remove plaque and dirt in the gumline around the base of the teeth similar to the scaler used by general dentists.

The objectives of this theses are: 1) to study the attitude motivation marketing mix and the decision to purchase second-hand brand name shoes from Facebook; 2 ) to compare personal factors i.e. gender age occupation education level that affecting decision to purchase second-handed brand name shoes from Facebook and; 3 ) to study factors affecting the decision to purchase second-handed brand name shoes from Facebook using the quantitative research methodology through an online survey tool in order to collect required data from 400 samples who actually purchased second-handed brand name shoes from 4 different Facebook pages. The pages were: 1) Second-handed shoes on Khao Lam Road FB Page 2) Taii Taew 2nd handed FB Page; 3) Shoes-Project FB Page; and 4) Cho Chopping FB Page. The data was analyzed by finding frequency percentage average t-test One-way Analysis of Variance and Enter Multiple Regression Analysis. The key research findings are: 1) Most of purchasers who decide to purchase second-handed shoes via Facebook are 215 males (62.50%) 162 are at aged over 51 years (40.50%) 178 are private business owners/entrepreneurs (44.50%) 214 posed bachelors degree or are currently studying (53%). 2) The study on motivation attitude for purchasing second-handed brand name shoes from Facebook found that respondents recognized cost saving as the most important key decision making factor in purchasing second-handed brand name shoes (x̅ = 4.36); followed by the user-friendly and uncomplicated purchasing process (x̅ = 4.19). 3) The study on motivation for purchasing the second-handed brand name shoes from Facebook found that the respondents recognized the importance of price advantage when comparing to the new brand name product (x̅ = 4.40) seconded by product limitation and availability in general local market (x̅ = 4.29). 4) Overall marketing mix factors of second-handed brand name shoes on Facebook was at high level (x̅ =3.79) in which price factor is at high level (x̅ = 4.32) followed by distribution factor ( x̅ = 4.23) product factor ( x̅ = 4.04) marketing promotion factor and market factor (x̅ = 3.89) respectively. 5) The study decision to purchase second-handed brand name shoes via Facebook found that respondents recognized the “convenience to purchase secondhanded brand name shoes via online channels fast and diverse in payment methods” as the most important factor (x̅ = 4.14) followed by personal preference (x̅ = 4.10). 6) From the hypothesis found that: 6.1) Gender age and education differences differentiated the decision to purchase second-handed brand name shoes from Facebook with a statistical significance at .05 level. 6.2) Attitude motivation and product marketing mix that included distribution sales & promotion affected the decision to purchase second-handed brand names shoes from Facebook with statistical significance at the .05 level.