Nowadays the majority of environment problem is pollution of vehicle including the noise of engine combustion. For this reason this thesis aims to compare and study the parameters which affect noise reduction on exhaust pipe. Not only reduce the noise pollution but also maintain the efficiency of the engine. These two substances must be considered. Therefore the researcher emphasized to study the parameters on 3 types of muffler with an equal volume: direct reverse and offset type of mufflers. Initiated by data collection the pressure and the velocity in muffler at the speed of engine at 1000 RPM (slow-running engine mode) and 4000 RPM (maximum running engine mode) were investigated. The data were applied into the program that called “SolidWorks” in order to study parameters. In this step the relation between the pressure and velocity of exhaust were represented. In addition the muffler models were selected to manufacture and test by the standard of The Department of Land Transport. As a result there are two major parameters of the muffler. Firstly the metamorphism of the exhaust gas flow direction pleasurably causes the lower noise at the speed of engine at 1000 RPM. Besides an increase of the flow gas distance can diminish noise at the speed of engine at 4000 RPM as well. However this muffler models were tested under the working mode of catalytic device that is standard equipment for automotive vehicles.

The aim of this research is to study the varieties of weight density distribution affect to the center of mass and vehicle stability. The weight density distribution tester was designed and changed the position of mass. Base on the center of mass is main points of vehicle stability. On the other hand FMCSA standard was applied to field test for considering of the brake performance and vehicle stability. The results of research discovered to the mass distribution on horizontal plane and fixed position Y1 are absolutely influence under an increasing 50 kilograms of mass condition. For the mass distribution on longitudinal plane and fixed position Z2 and Z3 are affected to the increasing of mass 100 and 150 kilograms respectively. Otherwise under an increasing of mass 200 and 250 kilograms there is non-influence to the weight density distribution. In term of the braking performance it’s depends on the lateral mass distribution especially the center position of mass installed on longitudinal and horizontal plane and close up on the front axle (Y2). For the vehicle stability results the position (Y2) is the highest influence for yaw rate and sideslip. Otherwise the position (Y3) or the position of mass installed on longitudinal plane and nearly at the left wheel on the rear axle. Additionally wheel lock-up condition was appeared on the front axle only. Because the behavior of the weight distribution on front axle was decreased lead to mass distribution on longitudinal plane.

Nowadays an automotive industry steadily has been growing and playing a major role on economy development for many years. The crash box is one of the most important parts for safety but it was found that the crash boxes manufactured domestically are not met international standard requirements. This is due to process and material limitation. This process for automotive safety test requires high budget and there is unclear approach for specific test. Therefore a study of crash boxes referred to energy absorption project was conducted as an alternative choice of testing. Regarding to the problems as addressed above this project was aimed to design and test crash boxes which come in various structures; simple type corrugated type and honeycomb type of crash box. In addition it was also emphasized in studying energy absorption behavior and physical deformation of crash boxes after dynamic and static energy being applied. Numeric simulation and static test methodology of front collision were applied for these tests in reference to USA NCAP standard for automobile collision test. Testing all types of crash boxes indicated that the corrugated type was able to absorb energy at 2.8% and 5.9% higher than honeycomb type and rectangular type respectively. This is capable to pick up stress and strain continually and effecting to more energy absorb than another type. Additionally this corrugated structure is feasible and suitable for crash box design in automotive manufacturing.

The objectives of this research are to estimate the morbidity rate of Dengue Hemorrhagic fever in each province of Thailand and to construct the map of the Dengue Hemorrhagic fever. A Bayesian model is used for the data analysis. The data are mathematical spatial correlated in the form of the conditional autoregressive model (CAR). The secondary data were collected at a provincial level. They were the number of Dengue Hemorrhagic fever patients rainfall and average temperature. The research found that the rainfall (RR = 1.0026) and the average temperature (RR = 1.2681) had influence on the morbidity of Dengue Hemorrhagic fever. The season during July to September had more influence on the morbidity of Dengue Hemorrhagic fever than during the other seasons. The top 5 highest morbidity rates per 100000 population were Chiangmai in October (1288.00) July (1096.00) September (804.30) Surin in October (772.30) and Nakhon Si Thammarat in August (666.20). The disease map constructed for showing the distribution of the disease is easy to understand and useful for public health.

This paper presents a low cost wireless sensor network system which is developed to be an alerting system for relatives or caregivers when the elder is immobile for a long period. The alerting signal is sent via the Internet link and a mobile phone. Remote transducers capture input signal from the mobility subject. If the target subject has immobilized behavior for long period which is analyzed abnormal condition the system will send the alerting messages to a selected mobile phone or Internet link. After detection of motionless elder from the set–point periods the system immediately distributes messages via SMS on the mobile network and a server to warn a relative or a caregiver with the image option to send. The sensor modules have ease-ofinstallation with coverage area nearly 3 square meters 80 % of detection level suitable for a small room and a bathroom