Oscillatory Stability Prediction Using PSO Based Synchronizing and Damping Torque Coefficients

This paper presents the assessment of stability domains for the angle stability condition of the power system using Particle Swarm Optimization (PSO) technique. An efficient optimization method using PSO for synchronizing torque coefficients Ks and damping torque coefficients Kd to identify the angle stability condition on multi-machine system. In order to accelerate the determination of angle stability, PSO is proposed to be implemented in this study. The application of the proposed algorithm has been justified as the most accurate with lower computation time as compared to other optimization techniques such as Evolutionary Programming (EP) and Artificial Immune System (AIS). Validation with respect to eigenvalues determination, Least Square (LS) method and minimum damping ratio ξmin confirmed that the proposed technique is feasible to solve the angle stability problems

Performance assessment of parabolic trough collector (ptc) by using three passes receiver for preheating the fuel oil under Iraq climate for different mass flow rates

An alternative design receiver of parabolic trough collector (PTC) has been discussed in the present study. The three passes design (3p) receiver made from copper and coated with selective black paint was studied and optimized experimentally. Mass flow rates were varied alongside number of days. The proposed design was compared with the PTC equipped with smooth receiver (SM). The aforementioned variations resulted in the experiments performed in September 2018. The 17th, 18th, 19th, and 20th, were chosen for the PTC with smooth receiver, while 25th , 26th, 27th, and 28th were for the receiver with three passes). The solar irradiances for these days were similar. The heat transfer fluid (HTF) was fuel oil. Mass flow rates of 2, 2.5, 3, 3.5 LPM were observed alongside change in number of days for the experiment. The results show that the PTC with three passes receiver achieved higher average thermal efficiency and average useful energy than the PTC with smooth receiver

Design, fabrication and modelling of four-wheeled mobile robot platform with two differential and two caster wheels

This paper presents a design and modeling of wheeled mobile robot (MWR) when navigating autonomously in environment such as road and factory. It needs a good and robust design and control for wheeled mobile robot to move from one to another points with smooth moving and small tracking errors. This paper is focused on mechanical design and modeling of wheeled mobile robot. Autodesk inventor software is used to draw the design of the WMR because this software is simple to make any design and a wheeled mobile robot structure is designed with a center of gravity to be located below the axle wheels level. The wheeled mobile robot is driven using two differential drive and two castor wheels to balance robot while it is moving in the environment. Two kinds of coordinate systems are used to describe the movement of the robot in the environment; namely are Local and global coordinate system; where local is related to the heading angle and the deferential wheel shaft, however the global describes the motion in x, y and z directions. The kinematic model is derived for the four wheeled mobile robot using angular velocities equations for the left and right wheels with estimation the heading angle of the robot

Penerapan Metode Variativ dalam Meningkatkan Pembelajaran Bahasa Indonesia di SMP Buru

Penelitian untuk mengeatahui pengaruh penerapan metode Metode Variative dalam meningkatkan hasil belajar isswa di SMP 9 Buru. Adapun Metode yang digunakan yakni deskriptif Kuantitatif. Metode deskriptif kuantitatif yaitu menggambarkan secara jelas dan nyata variabel penelitian dalam bentuk angka-angka dan statistik. Untuk memperoleh data penelitian, penulis menggunakan teknik pengumpulan yairu Angket atau kuesioner, sementara itu dalam menganalisis data penulis menggunakan analisis data distribusi frekuensi sedangkan mencari hubungan metode variatif dalam peningkatan motivasi belajar siswa kelas XII SMP Negeri 9 Buru, penulis menggunakan analisa statistik dengan rumus. Korelasi Product Momet. Karena data ini membahas dua variabel yang berhubungan. Rata-rata skor penggunaan metode variatif adalah 72,4 dan rata-rata nilai motivasi belajar siswa adalah 71. Untuk mengetahui apakah ada hubungan yang positif anatara Penggunaan metode variatif (variabel X) dengan motivasi belajar siswa (variabel Y), maka penulis menggunakan rumus Product Moment. Dari perhitungan di atas ternyata angka nilai koefisien korelasi antara hasil penelitian skor penggunaan metode variatif dengan nilai motivasi belajar siswa sangat signifikan

Lubricated wear behaviour of SiC reinforcement on TI-6AL-4V alloy based on Taguchi approach

Titanium alloy grade 5 (Ti-6Al-4V) is widely used in engineering industries as compared to the other titanium alloys. Ti-6Al-4V also has been known to show good mechanical properties, excellent corrosion resistance and having low density [1]. However, the grade 5 titanium alloys have poor tribological properties since it has poor wear resistance, low degree of hardness and high coefficient of friction [2]. There is a need to improve these properties to increase the performance of the engineering components and to extend their life service without any failure. Previous research work by Adeleke & Maleque [3] studied the surface alloying of commercial purity titanium (CP-Ti) using preplaced Fe-C-Si powder by TIG techniques. The surface modified CP-Ti alloy exhibited hardness values ranging from 600 Hv to 800 Hv which was 3 to 3.5 times higher than base metal hardness. The higher hardness observed at particular areas are attributed to high population and big sizes of dendritic microstructures of TiC. The main aim of this study is to improve the tribological properties of grade 5 (Ti-6Al-4V) under lubricated condition based on Taguchi approach. The substrate alloy was preplaced with silicon carbide (SiC) powder and tungsten inert gas (TIG) torch surface melting technique was applied

The Effect of Environmental Treatments on Fiber Surface Properties and Tensile Strength of Sugar Palm Fiber-Reinforced Epoxy Composites

Fiber glass has been used widely in manufacturing industries, especially marine industries, because of low cost and high strength. However, glass fiber can cause acute irritation to the skin, eyes, and upper respiratory tract. This study looked at the possibility of substituting glass fiber with natural fiber in composite materials. The surface properties of sugar palm fiber (Arenga pinnata) were modified using seawater and freshwater as treatment substances. This led to biological, chemical, and water degradation of the sugar palm fiber. Morphological and structural changes in the fibers were investigated using a scanning electron microscope (SEM). A series of tensile tests based on ASTM D638-99 was carried out on epoxy composites with 15% sugar palm fiber by volume. It was found that seawater and freshwater treatments improved the surface properties of the sugar palm fiber and thus resulted in better adhesion quality as compared to untreated fiber. An improvement in tensile strength also supported this finding. Treatment with seawater for 30 days proved to be the best, with 67.26% increase in tensile strength

Effect Of A Discrete PIN Diode On Defected Ground Structure

Email Print Request Permissions Save to Project This paper investigates the effect of a discrete PIN diode on Defected Ground Structure (DGS) where the different resonant frequency between ON and OFF state of the PIN diode is observed. Analytical modeling is determined and analyzed based on equivalent circuit of PIN diode and DGS. Then, a circuit simulation is performed using simulation software with different value of inductance and capacitance of DGS during ON and OFF state of the PIN diode. As a result, the resonant frequency of the PIN diode on the DGS shifted to higher frequency during ON state and shifted to lower frequency during OFF state. Besides, a larger value of inductance with a smaller value of capacitance of DGS will produce a larger range of resonant frequency between ON and OFF state and vice versa

An overview on real-time control schemes for wheeled mobile robot

The purpose of this paper is to review real-time control motion algorithms for wheeled mobile robot (WMR) when navigating in environment such as road. Its need a good controller to avoid collision with any disturbance and maintain a track error at zero level. The controllers are used with other aiding sensors to measure the WMR's velocities, posture, and interference to estimate the required torque to be applied on the wheels of mobile robot. Four main categories for wheeled mobile robot control systems have been found in literature which are namely: Kinematic based controller, Dynamic based controllers, artificial intelligence based control system, and Active Force control. A MATLAB/Simulink software is the main software to simulate and implement the control system. The real-time toolbox in MATLAB/SIMULINK are used to receive/send data from sensors/to actuator with presence of disturbances, however others software such C, C++ and visual basic are rare to be used

Oblique impact behavior of unidirectional natural fiber reinforced composites

This research focuses on the low velocity oblique impact on unidirectional (UD) kenaf reinforces composite plate. This study summarizes oblique impacts testing with angle 0°, 8° and 13° on three laminated layers of UD kenaf fiber with orientation structures of [0°, 30°, 0°] and [0°, 60°, 0°]. Nowadays, market ready composites mostly made-up using synthetic fibers, one of main problem when using synthetic fiber is hard to decompose and make its harms to environment. Natural fibers have high potential for replacing synthetic fibers as main composite materials. Kenaf fibers were chosen in this study due to relatively good mechanical properties with environmental friendly advantages. Kenaf yarn with the size of 855 Tex (1.0 mm diameter) is being used for UD kenaf fabric on the composite. Compression technique was used to prepare the composite with epoxy polymer as its resin. UD kenaf composite was tested using high speed puncher machine at speed 1m/s. Total energy absorption, load over displacement curves and fragmentation profile of the UD Kenaf composite are analyzed. By increasing oblique angle, the total energy absorption will decrease, load over displacement curves become fall off and the fragmentation profile of the composite become smaller had been revealed

Exploring the Effects of Board Characteristics on Innovation Capital Disclosure: Evidence from Malaysia

Innovation is one of the major determinants for competitive advantage and long-term success for business growth. As a result, there is an increased demand for information on innovation activities of firms among stakeholders. The main objective of this research is to investigate whether board characteristics influence the disclosure of innovation capital in the Malaysian public listed companies. The sample consists of 68 public listed companies in the Main Market of Bursa Malaysia over a five-year period from 2011 to 2015. The research employs content analysis methodology to measure the extent of the innovation capital disclosure in the annual report. The multiple regression analysis is then used to investigate the relationships between five board variables and innovation capital disclosure. In general, the extent of innovation capital disclosure indicates an increasing trend in the sample years. The result also reveals that there are significant differences between categories of innovation capital disclosure, with external capital identified as having the highest disclosure. The multiple regression results provide evidence that all five board variables were significantly associated with innovation capital disclosure. Board size, board independent, foreign directors, board meeting, and director age are related to the extent of innovation capital disclosure