จำนวน Repository ( 1852 )

Modeling and Forecasting the Demand for Automotive Part of Foreign Markets to Thailand
Modeling and Forecasting the Demand for Automotive Part of Foreign Markets to Thailand

The problem of this research is automotive part companies do not have order because of the world economic crisis and effect to automotive industry. Automotive and automotive parts demand in the world decrease. Automotive Industry of Thailand received affect. Automotive part companies cannot export to foreign markets. The companies in Thailand need the forecasting of automotive part quantity demanded by foreign markets by selecting the most accurate model. This paper presents the modeling for forecasting demand for automotive part of foreign markets to Thailand with time series forecasting techniques. In this study the automotive part are wheels and including parts and accessories because Thailand exported the most in group of automotive parts. These five countries have consistently demanded the largest number of wheels and including parts and accessories are Japan China South Korea Germany and Indonesia. The research involves historical collecting data for the period of 1997 to 2008. The evaluation function of forecast error is used with MAPE. The results reveal that each country suits for each model in term of the chosen dimension. The government can use the forecasting demand for effective production planning by informing manufactures.

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Fluctuation Voltage Control of Wind Turbines via STATCOM
Fluctuation Voltage Control of Wind Turbines via STATCOM

This paper presents distributed STATCOM for controlling voltage in distribution line with wind turbines generations at 48 volts. The connection of wind turbine to distribution systems may affect the voltage quality offered to the consumers. One of the factors contributing to this effect is the rapid variations of the wind turbine output power which cause respective fluctuations in the supply voltage. This paper presents the design control and analysis of a Distributed STATCOM when combined with a wind turbine comprising small variable speed generators in this paper it is shown that the distributed STATCOM controlled via a rotating referent frame: RRF and recursive DFT are simple method to DSP control technique. The result of experiments the STATCOM can improve the transient stability voltage of wind turbine that we have referred the IEEE1159:1995 standard of power quality.

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Influence of Electrode Force Affecting the Complete of the Resistance Spot Welding
Influence of Electrode Force Affecting the Complete of the Resistance Spot Welding

This research was to influence of electrode force affecting the complete of the resistance spot welding. The specimen was mild steel sheet metal has 1 mm. thickness. Then applied the force to the specimen are 1.0 2.0 3.0 4.0 and 5.0 kN. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and Macro structure testing according to JIS Z 3139: 1978.The results showed that electrode force had affected on tensile shear and nugget size at 95% confidential (P value > 0.05). The low electrode force had increase the nugget heating because it had a high resistance (Q=I2Rt) and increase the gab between specimen. When the resistance increasing so the current flow will difficult to passed that fusion zone will had a high heating. It will affected to nugget seize heat affected zone and mechanical properties decreasing. The electrode forces are complete 2.0 kN. Tensile shear 6.39 kN and Nugget Size 5.83 mm. This data can be applied to be used as process monitoring of resistance spot weld quality.

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Temperature Reduction in Hydroponic Planting System Using Heat Pipe
Temperature Reduction in Hydroponic Planting System Using Heat Pipe

This paper presents an establishment of a mathematical model to determine the optimal size of heat pipe (thermosyphon) heat exchanger for reduce the inlet air temperature in evaporative cooling system of greenhouse. The condition of a mathematical model is the total length of heat pipe is 1.5 m. A mathematical model will determine the optimal value of evaporator section and condenser section. The range of evaporator length is 0.5 – 1.4 m with an increment of 0.1 m and condenser length is in range of 0.1 – 1.0 m with an increment of 0.1 m. The inlet air temperature in evaporative cooling of greenhouse is depend on ambient temperature about 35 degree Celsius. While the cooling water temperature is 20 degree Celsius. Evaporative pad of evaporative cooling system is 2 m in width and 7 m in length. From the conditions above the optimize results from a mathematical model are as follows: evaporator section length is 0.9 m and condenser section length is 0.6 m moreover it was shown that investment net saving and maximum heat rate are 79.83 Thousand Baht 0.552 Million Baht and 15.6 kW respectively.

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A study of the participation with the  Education Quality Assurance in Rajamangala University of Technology Phra Nakhon
A study of the participation with the Education Quality Assurance in Rajamangala University of Technology Phra Nakhon

The objectives of this research were to examine the participation of students in the education quality assurance in Rajamangala University of Technology Phra Nakhon and compare the differences of participation rating scale based on personal factors. The study sample of 381 students was randomly selected from RMUTP undergraduate students in 9 faculties. The data were collected by questionnaire (5 rating scales) and analyzed by Statistical Package for Social Science (SPSS) to find statistic Percentage mean standard deviation (S.D) t-test and F-test. The test of hypotheses defined the statistical significance at level 0.5.

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