จำนวน Repository ( 757 )
The Mode Estimation Method of Inverse Gaussian Data
The objectives of this research are to propose the mode estimation method of Inverse Gaussian data and to compare three mode estimation methods. Those methods are simple method adjusted mode method with term (n+1)/n and adjusted mode method with term (n+2)/n. The performance of each method can be measured by the absolute bias (|Bias|) and the mean square errors (MSE). This study was performed by using different sample sizes (n) of 5 10 20 30 and 50 whereas the parameter is fixed to be 1 and parameters are fixed to be 1 3 5 10 15 and 20. This research used the Monte Carlo Simulation technique. The experiment was repeated 50000 times for each condition. The results showed that the adjusted mode method with term (n+2)/n gave the lowest value of |Bias| and MSE in most of the criterions of sample sizes and parameter values.
The Design of Bit-Serial Lattice Wave Digital Filter Using FPGA
This article describes an efficient approach to the implementation of bit-serial lattice wave digital filters based on field programmable gate array (FPGA). In this paper a time schedule of all of the bit-serial two-port adaptors is presented as a bridge between conception and completion. Finally with the satisfying frequency response the filter is successfully tested by both computer simulation and real signal measured from the programmed FPGA.
การปรับปรุงคุณภาพไฟฟ้าในระบบจำหน่ายไฟฟ้าโดยการเชื่อมต่อแหล่งผลิตไฟฟ้าแบบกระจายตัวพลังงานแสงอาทิตย์
This thesis presents improving power quality in power distribution system with integration of photovoltaic energy distributed generation having objectives to improve power quality in distribution system model of voltage sag and voltage swell in distribution system model of power loss in distribution system application of mathematical model model of power generation by using solar energy and distributed generation connection technique simulation. In this thesis the power flow was tested with Newton-Raphson algorithm joining with mathematical model. The case study was done by reduction of power loss in distribution system by using techniques of connection of distributed generation joining with model of distribution system 33 bus. The case study about improvement of voltage sag and voltage swell in distribution system used connection techniques of distributed generation joining with model of distribution system 69 bus. The study found that technique of connection of distributed generation that was presented could reduce power loss and showed the percentage of improvement of voltage sag and voltage swell in distribution system especially voltage sag case according to IEEE 1159-1995 standard. This thesis showed that severity level of voltage sag depended on the size and duration of each distribution system model situation by photovoltaic energy distributed generation can reduce voltage sag.
การศึกษาสมบัติทางกลของโพลิเอทิลีนน้ำหนักโมเลกุลสูงยิ่งยวดเชิงประกอบสำหรับล้อ Run-flat
This research project aimed to test the mechanical properties and the capability in wear resistance of ultra-high molecular weight polyethylene composite as well as determine the optimal formulation of UHMWPE-based composites which had a main component of aluminum oxide. The developed formula was used in the manufacture of run-flat wheels and thus applied to build run-flat wheels with an understanding of the proper molding conditions under the run-flat wheel forming process. Two materials used in the research consisted of super-high molecular weight polyethylene (UHMWPE) as the base material and the additive of aluminum oxide (Al2O3). The parameters employed in the hot compression process to obtain the specimen for the experiment consisted of compressive force temperature time and the ratio between super-high molecular weight polyethylene and aluminum oxide. The test for mechanical properties consisted of an impact test a hardness test according to the ASTM D2240 standard a tensile test according to the ASTM D638 standard type I and a wear test according to the ASTM G77 standard. The results indicated that a hot compression condition under a pressure of 5 MPa a temperature of 210°C for 90 min and using 5% Al2O3 HTM 30 material caused mixed uneven powder particle sizes between 2 to 5 µm. The tensile test results inferred the yield strength of 20.52 MPa ultimate tensile strength at 29.96 MPa breaking strength at 22.83 MPa elongation at break at 265.8% and modulus of elasticity at 784.46 MPa. The highest hardness was 62 shore D the high impact strength was 586.8 J/m and it was displayed for the wear rate of hot compression specimens made of UHMWPE mixed with 5% HTM-30. Moreover it introduced a coefficient of friction the wear rate and the density of 0.12 8.66E-11 mm3/N.m and 1.2446958 g/cm3 respectively.
การเพิ่มประสิทธิภาพการผลิตอิฐช่องลมลวดลายอาหรับ การณีศึกษา : มุสลิมโมเดิร์น์ จังหวัดปัตตานี
The objective of this study is to improve the efficiency in manufacturing process of Arabian-style ventilation bricks with a new production method that uses a machine. The study focuses on all steps of productions in order to increase productivity. After the experiment the study shows that the improvement of ventilation brick manufacturing includes the increase in production volume from 20 pieces per day to 50 pieces per day representing an increase of 76.19 percent; and the decrease in production cycle time originally from 1401 minutes per piece to 97 minutes per piece representing a decrease of 93.07 percent respectively.