Design of grounding system to protect against lightning and fault is important for both safety and reliability especially for Metropolitan Electricity Authority (MEA) as mostly Metropolitan Electricity Authority operates on overhead networks. This thesis assesses lightning performance for 69 kV 115 kV overhead subtransmission lines 24 kV distribution line using case study from Metropolitan Electricity Authority. Because of the limitation of the right of way distribution feeders are regularly installed together with subtransmission lines in a single concrete pole. Overhead Ground Wire (OHGW) installed at top of the pole and grounding system in concrete pole protects fault current or direct lightning surge to ground. Metropolitan Electricity Authority has developed lightning protection based on an IEEE standard which uses international data for insulation coordination. As a result reliability of the system is lower than the designed value. This thesis suggests a methodology to improve the performance in order to increase the reliability of subtransmission and distribution lines feeding distribution substations. This thesis recommends installation of addition external ground wire on the outer surface of the concrete pole to reduce top pole voltage and back flashover rate or installation of bundle overhead ground wires to protect shielding failure. As all the case studies presented in the thesis which constitute this thesis are applied to existing systems of Metropolitan Electricity Authority it is expected that the proposed methodologies can be served as useful practical guidelines for lightning performance assessment subtransmission lines and distribution lines of Metropolitan Electricity Authority.

Most of Metropolitan Electricity Authority (MEA) electric power system is using overhead line. It is 94% in the system including subtransmission distribution and low voltage system. All of them were installed on concrete pole. At present many public facilities have been built such as Sky-Train. It causes more constrains for construction with concrete pole due to lack of right of way. MEA needs to using electrical monopole plays an important role. It’s easier than concrete pole for construction and it requires less construction area than concrete pole. The thesis evaluation of lightning performance in subtransmission line 69 kV study on MEA. Case lightning strike on overhead ground wire (OHGW) at pole top of electrical monopole with suspension insulator Focusing on three factors is pole top voltage critical current and back flashover rate (BFOR). ATP-EMTP software is used for simulation. The results show that BFOR is reduced by 79% on electrical monopole structure with suspension insulator compared with existing concrete pole. BFOR is also reduced by 33.17% on concrete pole with external ground wire. The results could be served as a guideline in subtransmission line design and improvement in MEA power system.

The objectives of this research were to study the personal and environment and investment experiences factors influencing decision making to invest in the provident funds of The Office of the Rubber Replanting Aid Fund’s Staffs. The sample consisted of 341 persons from Rubber Replanting Aid Fund’s staffs at Bangkok office (central region). The research instrument was a questionnaire and using the descriptive statistic such as mean percentage standard deviation to analyze the data and Exploratory Factor Analysis : EFA and Binary Logistic Regression Analysis to test the hypothesis. The results of the study found that sex age the knowledge and investment experiences the risks of investment the economy the politics differences influencing the decision making to invest in the provident funds of The Office of the Rubber Replanting Aid Fund’s Staffs at statistically 0.05 significant level.

The objective of this research aimed to study factors affecting earning persistence and firm value of list firms in the stock exchange of Thailand in set 100 Index. The data was collected in 5 years period from 2011 – 2015 which including 213 samples and then analyzed data by using descriptive statistics and multiple regression analysis. The research revealed growth rate of sales current earnings and cash flow for short term investment reflected to earnings persistence. Furthermore this research also shed some light on factors affecting firm value and found that earnings persistence financial risk dispersed ownership structure and discretionary accrual directly affected to firm value. These results provided more information to investors about significant factors for decision making especially discretionary accrual factor. Therefore firms who have low level of earnings management and high level of earning persistence will reflect to future firm value.

This research was aimed to analyze work performance classified by personal information to investigate internal factors of support personnel work performance and influence of internal factors affecting work performance of the support personnel at Rajamangala University of Technology Phra Nakhon. The population used in this study was 693 staff working at Rajamangala University of Technology Phra Nakhon Bangkok. The sample size was determined by Craig and Morgan method to draw out 250 samples. The research instrument was a questionnaire constructed by the researcher to collect data manually. The data obtained from the questionnaire were analyzed using percentage mean standard deviation and T-test F-test ANOVA Pearson coefficient and multiple regression analysis. The research revealed the results as follows. Work performance of the support personnel of Rajamangala University of Technology Phra Nakhon in the overall was at high level with the mean Organization factors of the support personnel of Rajamangala University of Technology Phra Nakhon in the overall was at high level with the The results of the study on personal factors agreed with the overall performance of Rajamangala University of Technology Phra Nakhon personnel. It was found that the status salary and educationhours and working centers were significantly different .