The field oriented control of a permanent magnet synchrounous motor (PMSM) by using fuzzy logic

This project presents the comprehensive performance analysis on the principle of operation, design considerations and control algorithms of the field oriented control (FOC) for a permanent magnet synchronous motor (PMSM) drive system of Fuzzy Logic Controller (FLC) and proportional-integral PI for speed control in closed loop operation. To perform speed control of typical PMSM drives, PI controllers and FOC method are classically used. PI Controller controller suffers from the drawback that for its proper performance, the limits of the controller gains and the rate at which they would change have to be appropriately chosen. Fuzzy based gain scheduling of PI controller has been proposed in which uses in order to overcome the PI speed controller problem. The simulation results show that the proposed FLC speed controller produce significant improvement control performance compare to the PI controller. FLC speed controller produced a better performance than PI speed controller where the overshoot is totally removed and the settling time faster than PI speed controller in achieving desired output speed. The fuzzy algorithm is based on human intuition and experience and can be regarded as a set of heuristic decision rules. It is possible to obtain very good performance in the presence of varying load conditions changes of mechanical parameters and inaccuracy in the process modelling. Research and application of fuzzy logic are developing very rapidly, with promising impacts on electric drives and power electronics in future. Keywords: FOC, PMSM, FLC, PI and for Speed Control

Studi Interaksi Seng(II) pada Asam Humat Muara Kuang Serta Aplikasinya terhadap Limbah Industri Pelapisan Seng

Telah diekstraksi asam humat dari tanah gambut asal Muara Kuang dengan menggunakan natrium hidroksida dalam kondisi atmosfir nitrogen. Asam humat yang diperoleh dikarakterisasi dengan spektroskopi infra merah, kadar air dan kadar abu untuk selanjutnya digunakan sebagai material untuk mengikat kation seng(II) dalam medium air dan diterapkan untuk mengikat kation dalam limbah industri pelapisan seng. Hasil penelitian menunjukkan bahwa asam humat dari tanah gambut asal Muara Kuang mengandung gugus karboksilat (-COOH) dengan kadar abu sebesar 26,04% (b/b) dan kadar air sebesar 14,16%(b/b). Kation Zn(II) yang terikat pada asam humat hasil isolasi sebanyak 96,79%. Asam humat hasil isolasi dapat mengikat kation Zn(II) dari limbah industri pelapisan seng sebesar 8,814%

Top-down inputs enhance orientation selectivity in neurons of the primary visual cortex during perceptual learning.

Perceptual learning has been used to probe the mechanisms of cortical plasticity in the adult brain. Feedback projections are ubiquitous in the cortex, but little is known about their role in cortical plasticity. Here we explore the hypothesis that learning visual orientation discrimination involves learning-dependent plasticity of top-down feedback inputs from higher cortical areas, serving a different function from plasticity due to changes in recurrent connections within a cortical area. In a Hodgkin-Huxley-based spiking neural network model of visual cortex, we show that modulation of feedback inputs to V1 from higher cortical areas results in shunting inhibition in V1 neurons, which changes the response properties of V1 neurons. The orientation selectivity of V1 neurons is enhanced without changing orientation preference, preserving the topographic organizations in V1. These results provide new insights to the mechanisms of plasticity in the adult brain, reconciling apparently inconsistent experiments and providing a new hypothesis for a functional role of the feedback connections

Taburan dan Populasi Ikan Air Tawar di Beberapa.Altitud di Taman Kinabalu Sabah, Malaysia.

A survey was conducted to study the distribution and population of freshwater fish fauna of the Kinabalu Park.. Fishes were sampled using electro shocker; the impact of water quality was also studied. Physical parameters were determined in-situ while several nutrient and heavy metal contents were analysed in the laboratory. A total of 22 species were found, representing5families. Rasbora hubbsi, Osteochilus spilurus and Nematabramis alestes are new listings for this area. Oreochromis mossambicus and Trichogaster trichopterus were not found although they had been reported previously. The distribution and population offish were found to vary according to altitude and several physical parameters of the waters

Screening Of Malaysian Medicinal Plants For Immunomodulatory And Haemolytic Activities

Twenty-six water-soluble extracts from eighteen local medicinal plant specirs and fourteen methanol extracts from ten medicinal plants were screened in order to find new immunomodulating substances from those medicinal plants. Effects on lymphocyte proliferation and macrophage function in host defense mechanism including the nitric oxide (NO) production, phagocytic activity and intracellular killing ability were tested. Lymphocyte or macrophage was treated with those extracts at the concentration of 2.5 - 50J..lg/ ml. Four of the water-soluble extracts shows mitogenicity where it causes highest mitogenicity at different concentrations. Both methanol and water-soluble extracts failed to alter or improve macrophage function neither of its phagocytic activity nor its intracellular killing ability. The water extracts of S. torvum (stem bark), C. asiatica, S. grandiflora, U. lobata (stem bark) and G. vulgaris (leaves) produce NO significantly. Apart from that, haemolyti c activity was also determined

Organizational factors, individual factors, perceived organizational support and perceived public recognition on unethical behavior among police personnel / Nusrah Samat

Ethics has been an issue of enormous interest and growing concern from time to time in most areas including in the management field. The inculcation of unethical behavior in both public and private organizations has proven to be an elusive and never ending quest. The issue of unethical conduct is also evident in Malaysia. This can be seen by the increasing frequency of coverage in media, printing and electronic, on unethical behavior and misconducts by individuals and local organizations. Unethical behaviors lead to a wide range of negative consequences. The costs associated with unethical behavior in the organization are great, estimated to be in the amount of billions annually as well as it may negatively impact the organizations’ ability to achieve sustained profitability. This will lead to financial failure and will have a deep impact on its stakeholders or might even harm the strength of the society. A study on the determinants of unethical behavior is deemed important. This will help organizations in determining which variables contribute to such behavior. Amidst the widespread concern regarding the high incidence of crimes, perceptions of corruption in the Royal Malaysia Police (RMP), and general dissatisfaction with the conduct and performance of police personnel, there is a desire to see improvements in the services provided by the police. Thus, the main purpose of this study is to investigate the antecedents of unethical behavior among police personnel as government servants

Bauran Pemasaran terhadap Keputusan Mahasiswa Memilih Perguruan Tinggi Swasta di Kota Palembang

Tujuan penelitian – Penelitian ini membahas tentang Bauran Pemasaran Terhadap Keputusan Mahasiswa Memilih Perguruan Tinggi Swasta di Kota Palembang. Dengan tujuan untuk mengetahui pengaruh bauran pemasaran yang terdiri dari Product, Price, Promotion, Place, Personal traits, Process, dan Physical Evidence terhadap keputusan mahasiswa dalam memilih Perguruan Tinggi Swasta di Kota Palembang.Desain/Metodologi/Pendekatan – Populasi yang digunakan dalam penelitian ini adalah mahasiswa yang kuliah di lima perguruan tinggi swasta di Kota Palembang. Sampel yang digunakan dalam penelitian ini sebanyak 110 mahasiswa yang dijadikan sebagai responden. Teknik analisa data yang digunakan adalah Structural Equation Modeling (SEM).Temuan – Hasil pengujian membuktikan bahwa: 1). Secara parsial didapatkan hasil bahwa ada pengaruh yang signifikan dan positif Product, dan Promotion terhadap keputusan mahasiswa dalam memilih Perguruan Tinggi Swasta di Kota Palembang, sedangkan Price, Place, Personal traits, Process, dan Physical Evidence tidak berpengaruh secara segnifikan terhadap keputusan mahasiswa dalam memilih Perguruan Tinggi Swasta di Kota Palembang. 2) Secara simultan didapatkan hasil bahwa ada pengaruh yang signifikan dan positif terhadap keputusan mahasiswa dalam memilih Perguruan Tinggi Swasta di Kota Palembang.Keterbatasan penelitian – Penelitian ini fokus meneliti tentang faktor bauran pemasaran yang mempengaruhi keputusan mahasiswa, terdapat faktor-faktor lain yang dapat dikembangkan untuk penelitian lanjutan seperti branding, jasa maupun faktor perilaku konsumen lainnya.Originality/value – Penelitian ini membandingkan bauran pemasaran dari organisasi yang sejenis yaitu perguruan tinggi swasta di kota Palembang

Diagonally implicit hybrid method for solving special second order ordinary differential equations

This paper describes the derivation of a fifth-order diagonally implicit hybrid method. The method is zero dissipative and has phase-lag of order six. The method is compared with the existing hybrid method and the numerical comparisons carried out show that the new method improves the accuracy of the existing method for solving several special second order ordinary differential equations