Hadi Akbar - Academia.edu (original) (raw)

Papers by Hadi Akbar

Heavy metal pollution to the soil environment has become a major source of concern and has posed ... more Heavy metal pollution to the soil environment has become a major source of concern and has posed serious health problems to humans and other ecological systems worldwide. Phytoremediation is a biological treatment where plants are used to remove pollutant from environment. An experiment was conducted to evaluate the potentiality of Melastoma malabathricum as a phytoremediator to absorb heavy metals from soil contaminated with sewage sludge. Melastoma malabathricum seedlings were planted on six different growth media: T0 - Control (100% soil), T1 (80% soil + 20% sewage sludge), T2 (60% soil + 40% sewage sludge), T3 (40% soil + 60% sewage sludge), T4 (20% soil + 80% sewage sludge) and T5 (100% sludge). There were significant difference found in growth parameters and plant biomass. The highest growth performance such as plant height and number of leaves and finally biomass was found in T3. However after harvest, the concentration of Zn in growth medium was decreased due to effective ab...

Scientia Agricola, 2018

Heavy metal pollution of the soil environment has become a major source of concern and continues ... more Heavy metal pollution of the soil environment has become a major source of concern and continues to pose serious health problems to both humans and ecological systems worldwide. Phytoremediation is a biological treatment whereby plants are used to remove pollutant from the environment. An experiment was conducted to evaluate the potential of Melastoma malabathricum as a phytoremediator to absorb heavy metals from soil contaminated with sewage sludge. Melastoma malabathricum seedlings were planted on six different growth media: T 0-Control (100 % soil), T 1 (80 % soil + 20 % sewage sludge), T 2 (60 % soil + 40 % sewage sludge), T 3 (40 % soil + 60 % sewage sludge), T 4 (20 % soil + 80 % sewage sludge) and T 5 (100 % sludge). There were differences found in both growth parameters and plant biomass. The highest growth performance such as plant height and number of leaves was found in T 3. Iron was highly accumulated in the roots, Cu in the stems in T 3 , while Pb was accumulated in leaves in T 5. The results showed the lowest Translocation Factor (TF) and highest Bioconcentration Factor (BCF) values in relation to the following elements: Cu, Fe, Mn, Pb and Zn. Melastoma malabathricum roots are able to uptake and translocate the elements into the plant's shoots. Therefore, it can be considered a good accumulator plant due to its capability of concentrating contaminants in aerial tissue. Melastoma malabathricum were thus found to be suitable for absorbing heavy metals in contaminated soils, and this species can also be considered an effective phtyoremediator of contaminated soil and mitigator of soil pollution.

Science of The Total Environment

The increasing of population in Malaysia has led to the increasing of sewage sludge from differen... more The increasing of population in Malaysia has led to the increasing of sewage sludge from different area such as domestic and industrial area. Disposing of sewage sludge on cropland is the most economical way because it gives beneficial to the plants. However, it gives a serious impact to the human, plants, animal and environment due to high concentration of heavy metals. Phytoremediation is a green technology that can remove pollutant especially heavy metals from soil contaminated with sewage sludge. Ricinus communis were planted on six different planting media T0 (100% soil-Control), T1 (80% soil + 20% sewage sludge), T2 (60% soil + 40 % sewage sludge), T3 (40% soil + 60% sewage sludge), T4 (20% soil + 80% sewage sludge) and T5 (100% sewage sludge). The results showed that addition of sewage sludge led to increase in pH and also increase in cation exchange capacity (CEC), exchangeable bases (K, Ca and Mg), available phosphorous (available P) and total carbon (TC). All the parameter...

The cost to dispose of sludge is very high, and Malaysia usually treats it by composting. However... more The cost to dispose of sludge is very high, and Malaysia usually treats it by composting. However, composting is not a feasible method because it is time consuming. The application of sewage sludge on cropland is economical method because it provides the plant nutrients. However, it has a serious impact on the plants, animal and environment due to high concentration of heavy metals. Therefore, phytoremediation is a green technology to remove pollutants especially heavy metals from contaminated soil. This study was conducted to determine the potential of Ricinus communis to remove heavy metal in soil. The seedlings were planted on six different planting media T0 (100% soil-Control), T2 (80% soil + 20% sewage sludge), T3 (60% soil + 40 % sewage sludge), T4 (40% soil + 60% sewage sludge), T5 (20% soil + 80% sewage sludge) and T6 (100% sewage sludge). The highest accumulation of Mn was observed in leaves. Ricinus communis were found to be suitable as phytoremediators to clean heavy meta...

Scientific Research and Essays, Jun 15, 2014

Kenaf is an industrial crop with high potential for cultivation in a tropical climate. It is a so... more Kenaf is an industrial crop with high potential for cultivation in a tropical climate. It is a source of raw material for fiber-based industries and paper production. Considerable research has been conducted to explore its adaptability and utilization in Malaysia since 2000, under the supervision of governmental and private organizations. A number of technologies and expertise among researchers have been developed to enhance kenaf production in Malaysia. However, international documentation of the research is limited, which is important for rectification to provide a comprehensive knowledge base for all tropical and subtropical countries. The main objective of this review is to provide an overview of the results of Malaysian research on kenaf. In addition, the past, present and likely future trends in kenaf research in Malaysia as a representative tropical region are summarized.

HTML (HyperText Markup Language) merupakan bahasa asas bagi pembangunan aplikasi berasaskan web. ... more HTML (HyperText Markup Language) merupakan bahasa asas bagi pembangunan aplikasi berasaskan web. Pemahaman asas terhadap bahasa ini adalah perlu untuk membina dokumen web yang mudah. Apabila asas yang kukuh diguna pakai atau dikuasai, anda mampu membina jaringan dokumen web yang lebih rumit. Mempelajari dan menguasai HTML merupakan satu titik permulaan untuk mempersiapkan diri dengan pelbagai gelagat dalam dunia internet di masa sekarang. Buku ini menjelaskan kaedah pembinaan dokumen web menggunakan HTML dan sesuai dipelajari oleh pembaca daripada kalangan semua peringkat pendidikan.

African Journal of Agricultural Research, Aug 1, 2013

Availability of nutrients for plant uptake is directly related to soil pH and as an indicator of ... more Availability of nutrients for plant uptake is directly related to soil pH and as an indicator of soil fertility status. Determination of effects of soil amendments on soil pH should be a necessary part of fertilizer and fertility research. A pot experiment was carried out to determine and compare the effects of biochar, chicken manure, urea and zeolite on soil pH variability and elevation in a sandy loam acidic soil. A modified method was used to determine the soil pH in the pots. Soil pH in pot was measured by a glass micro-electrode and spatial variability was interpolated and mapped by using geographic information system (GIS) + software. Kriged Maps clearly showed the presence of variability and elevation in pH within each treatment. Furthermore, the position of patches with maxima and minima values for pH changed between all treatments used in the experiment. The highest elevation was found in zeolite treated soil followed by urea and biochar. However, a significant decrease was measured in soil pH in chicken dung treated soil. These findings could be the first step towards temporal stability of the pattern of spatial distribution of soil pH affected by the soil amendments (biochar, urea, chicken manure and zeolite).

For government and non-government organisations to prosper, the practice and culture of innovatio... more For government and non-government organisations to prosper, the practice and culture of innovation must be adopted. Therefore, innovation has been encouraged for each organisation by the Malaysian government since the year 2009. This paper discusses on the innovation processes in two organisations; the Science & Technology Research Institute for Defence (STRIDE), a government agency, and Celcom Axiata Berhad, a public listed company. This study is conducted based on information on innovation activities gathered from representatives from both organisations’ top managements. STRIDE, being the government’s R&D centre for defence & security, and Celcom, a telecommunications service provider, have unique ways of implementing innovations in their respective departments. This paper focuses on both organisations’ achievements with their latest innovations, their plans for the next five to ten years, and the challenges faced in maintaining and improving their performances. Organisation strat...

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2015

In this paper, a hybrid control system called as backstepping adaptive fuzzy control system, whic... more In this paper, a hybrid control system called as backstepping adaptive fuzzy control system, which integrates nominal and compensation controller is developed for autonomous quadrotor helicopter with inherent time-varying disturbance. In this hybrid control system, the nominal controller based on backstepping technique is the main controller, and the compensation controller containing a fuzzy control approach is used to eliminate the effect of uncertainties caused by external disturbance. In addition, in order to relax the requirement of prior knowledge on the bound of external disturbance, an online adaptation law is derived. Asymptotical stability of the closed-loop control system is analytically proven via the Lyapunov theorem. For the problem of determining the backstepping control parameters, particle swarm optimization algorithm has been employed. Finally, the designed controller is experimentally evaluated on a quadrotor simulation environment to demonstrate the effectiveness...

Transactions of the Institute of Measurement and Control, 2014

Designing a controller for multi-input–multi-output (MIMO) uncertain non-linear systems is one of... more Designing a controller for multi-input–multi-output (MIMO) uncertain non-linear systems is one of the most important challenging works. In this paper, the contribution is focused on the design and analysis of an intelligent adaptive backstepping control for a MIMO quadrotor helicopter perturbed by unknown parameter uncertainties and external disturbances. The design approach is based on the backstepping technique and uses a radial basis function neural network (RBFNN) as a perturbation approximator. First, a backstepping controller optimized by the particle swarm optimization is developed for a nominal helicopter dynamic model. Then, the unknown perturbations are approximated based on the universal approximation property of the RBFNN. The parameters of the RBFNN are adjusted through online learning. To improve the control design performance further, a fuzzy compensator is introduced to eliminate the approximation error produced by the neural approximator. Asymptotical stability of t...

2014 5th International Conference on Intelligent and Advanced Systems (ICIAS), 2014

ABSTRACT In this paper, a fuzzy supervisory backstepping controller (FSBC) is designed for the al... more ABSTRACT In this paper, a fuzzy supervisory backstepping controller (FSBC) is designed for the altitude and attitude stabilization of quadrotor unmanned aerial vehicle (UAV). The designed controller consists of a backstepping controller which can automatically select its parameters, on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Numerical simulations using the dynamic model of a four degree of freedom (DOF) quadrotor UAV show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor UAV with better performance than established linear design techniques.

Journal of Intelligent & Robotic Systems, 2014

ABSTRACT Quadrotor unmanned aerial vehicle (UAV) is an underactuated multi-input and multi-output... more ABSTRACT Quadrotor unmanned aerial vehicle (UAV) is an underactuated multi-input and multi-output (MIMO) system which has nonlinear dynamic behavior such as high coupling degree and unknown nonlinearities. It is a great challenge to design a quadrotor control system due to these features. In this paper, the contribution is focused on the backstepping-based robust control design of the quadrotor UAV. Firstly, the dynamic model of the aerial vehicle is mathematically formulated. Then, a robust controller is designed for the stabilization and tracking control of the vehicle. The developed robust control system comprises a backstepping and a proportional-derivative (PD) controller. Backstepping is a recursive design methodology that uses Lyapunov theorem which can guarantee the stability of the nominal model system, while PD control is used to attenuate the effects caused by system uncertainties. For the problem of determining the backstepping control parameters, particle swarm optimization (PSO) algorithm has been employed. In addition, the genetic algorithm (GA) technique is also adopted for the purpose of performance comparison with PSO scheme. Finally, the designed controller is experimentally evaluated on a quadrotor simulation environment to demonstrate the effectiveness and merits of the theoretical development.

2013 IEEE International Conference on Control System, Computing and Engineering, 2013

ABSTRACT Microfluidic devices are important for the single cell analysis such as cell mechanical ... more ABSTRACT Microfluidic devices are important for the single cell analysis such as cell mechanical and electrical characterization. Single cell characterization could be related to many significant applications including early disease diagnosis. However to perform the single cell manipulation, firstly a single cell have to be isolated and a platform for the cell manipulation have to be provided. One of the methods to trap a single cell is by using hydrodynamic trapping in the microfluidic channel. This study provides a finite element model for single cell trapping for a yeast cell model. The objectives of the simulations are to obtain the appropriate channels' geometry and optimized ratio of the fluid's inlet and suction flow rate to trap a single yeast cell. Trap channel was designed to trap a 5 µm yeast cell with a suction hole placed in the end of the trap channel. Design geometry and ratio of fluid flow rates referring to the hydrodynamic concept were studied for the cell trapping model. The analysis was carried out using numerical solutions from the finite element ABAQUS-FEA software. Using the cell trapping model, a single yeast cell able to be trapped into the trap channel with optimized channel's suction hole's geometry and appropriate fluid's inlet and suction flow rate ratio.

2011 Third International Conference on Computational Intelligence, Modelling & Simulation, 2011

... Faculty of Electrical Engineering Universiti Teknologi Malaysia 81300 Skudai, Johor, Malaysia... more ... Faculty of Electrical Engineering Universiti Teknologi Malaysia 81300 Skudai, Johor, Malaysia Centre of Artificial Intelligent and Robotics (CAIRO), Universiti Teknologi Malaysia, Jalan Semarak, 54100, Kuala Lumpur ... [16] Yuchun Tang, Yan-Qing Zhang, Nitesh V. Chawla, and ...

2011 Second International Conference on Intelligent Systems, Modelling and Simulation, 2011

In this paper, Probabilistic Neural Network with image and data processing techniques was employe... more In this paper, Probabilistic Neural Network with image and data processing techniques was employed to implement an automated brain tumor classification. The conventional method for medical resonance brain images classification and tumors detection is by human inspection. Operator-assisted classification methods are impractical for large amounts of data and are also non-reproducible. Medical Resonance images contain a noise caused by operator performance which can lead to serious inaccuracies classification. The use of artificial intelligent techniques for instant, neural networks, and fuzzy logic shown great potential in this field. Hence, in this paper the Probabilistic Neural Network was applied for the purposes. Decision making was performed in two stages: feature extraction using the principal component analysis and the Probabilistic Neural Network (PNN). The performance of the PNN classifier was evaluated in terms of training performance and classification accuracies. Probabilistic Neural Network gives fast and accurate classification and is a promising tool for classification of the tumors.

Jurnal Teknologi, 2014

Microfluidic devices are important for the single cell analysis such as cell mechanical and elect... more Microfluidic devices are important for the single cell analysis such as cell mechanical and electrical characterization. Single cell characterization could be related to many significant applications including early disease diagnosis. However to perform the single cell manipulation, firstly a single cell have to be isolated and a platform for the cell manipulation have to be provided. One of the methods to trap a single cell is by using hydrodynamic trapping in the microfluidic channel. This study provides a finite element model for single cell trapping for a yeast cell model. The objectives of the simulations are to obtain the appropriate channels’ geometry and optimized ratio of the fluid’s inlet and suction flow rate to trap a single yeast cell. Trap channel was designed to trap a 5μm yeast cell with a suction hole placed in the end of the trap channel. Design geometry and the ratio of fluid flow rates for the cell trapping model were studied using the hydrodynamic resistance con...

Jurnal Teknologi, 2011

Artikel ini membentangkan pembangunan sebuah hidung elektronik (e–Hidung) mudah alih berdasarkan ... more Artikel ini membentangkan pembangunan sebuah hidung elektronik (e–Hidung) mudah alih berdasarkan kad perolehan data National Instrument dan LabView. Kajian ini merangkumi rekabentuk litar e–Hidung yang terdiri daripada pelbagai jenis semikonduktor oksida logam daripada FIGARO sebagai sensor gas. Rintangan dari setiap sensor gas diukur melalui litar arus tetap yang dikawal melalui LabView. Sumber arus tetap digunakan sebagai antara muka elektronik bolehubah yang membolehkan pemetaan voltan keluaran sensor untuk profil rintangan sensor dilakukan secara tepat. Rintangan dari setiap sensor dikira secara tepat dan dipaparkan oleh LabView. Keputusan kajian menunjukkan bahawa e – Hidung yang dihasilkan boleh mengesan dan mengklasifikasikan antara dua jenama terkenal iaitu Body Shop dan Avon. Kaedah analisis komponen utama (PCA) yang digunakan menunjukkan diskriminasi besar iaitu 99.53% untuk bau tersebut. Ini menunjukkan bahawa sistem yang dihasilkan mampu membezakan baud an akan digunakan...

Heavy metal pollution to the soil environment has become a major source of concern and has posed ... more Heavy metal pollution to the soil environment has become a major source of concern and has posed serious health problems to humans and other ecological systems worldwide. Phytoremediation is a biological treatment where plants are used to remove pollutant from environment. An experiment was conducted to evaluate the potentiality of Melastoma malabathricum as a phytoremediator to absorb heavy metals from soil contaminated with sewage sludge. Melastoma malabathricum seedlings were planted on six different growth media: T0 - Control (100% soil), T1 (80% soil + 20% sewage sludge), T2 (60% soil + 40% sewage sludge), T3 (40% soil + 60% sewage sludge), T4 (20% soil + 80% sewage sludge) and T5 (100% sludge). There were significant difference found in growth parameters and plant biomass. The highest growth performance such as plant height and number of leaves and finally biomass was found in T3. However after harvest, the concentration of Zn in growth medium was decreased due to effective ab...

Scientia Agricola, 2018

Heavy metal pollution of the soil environment has become a major source of concern and continues ... more Heavy metal pollution of the soil environment has become a major source of concern and continues to pose serious health problems to both humans and ecological systems worldwide. Phytoremediation is a biological treatment whereby plants are used to remove pollutant from the environment. An experiment was conducted to evaluate the potential of Melastoma malabathricum as a phytoremediator to absorb heavy metals from soil contaminated with sewage sludge. Melastoma malabathricum seedlings were planted on six different growth media: T 0-Control (100 % soil), T 1 (80 % soil + 20 % sewage sludge), T 2 (60 % soil + 40 % sewage sludge), T 3 (40 % soil + 60 % sewage sludge), T 4 (20 % soil + 80 % sewage sludge) and T 5 (100 % sludge). There were differences found in both growth parameters and plant biomass. The highest growth performance such as plant height and number of leaves was found in T 3. Iron was highly accumulated in the roots, Cu in the stems in T 3 , while Pb was accumulated in leaves in T 5. The results showed the lowest Translocation Factor (TF) and highest Bioconcentration Factor (BCF) values in relation to the following elements: Cu, Fe, Mn, Pb and Zn. Melastoma malabathricum roots are able to uptake and translocate the elements into the plant's shoots. Therefore, it can be considered a good accumulator plant due to its capability of concentrating contaminants in aerial tissue. Melastoma malabathricum were thus found to be suitable for absorbing heavy metals in contaminated soils, and this species can also be considered an effective phtyoremediator of contaminated soil and mitigator of soil pollution.

Science of The Total Environment

The increasing of population in Malaysia has led to the increasing of sewage sludge from differen... more The increasing of population in Malaysia has led to the increasing of sewage sludge from different area such as domestic and industrial area. Disposing of sewage sludge on cropland is the most economical way because it gives beneficial to the plants. However, it gives a serious impact to the human, plants, animal and environment due to high concentration of heavy metals. Phytoremediation is a green technology that can remove pollutant especially heavy metals from soil contaminated with sewage sludge. Ricinus communis were planted on six different planting media T0 (100% soil-Control), T1 (80% soil + 20% sewage sludge), T2 (60% soil + 40 % sewage sludge), T3 (40% soil + 60% sewage sludge), T4 (20% soil + 80% sewage sludge) and T5 (100% sewage sludge). The results showed that addition of sewage sludge led to increase in pH and also increase in cation exchange capacity (CEC), exchangeable bases (K, Ca and Mg), available phosphorous (available P) and total carbon (TC). All the parameter...

The cost to dispose of sludge is very high, and Malaysia usually treats it by composting. However... more The cost to dispose of sludge is very high, and Malaysia usually treats it by composting. However, composting is not a feasible method because it is time consuming. The application of sewage sludge on cropland is economical method because it provides the plant nutrients. However, it has a serious impact on the plants, animal and environment due to high concentration of heavy metals. Therefore, phytoremediation is a green technology to remove pollutants especially heavy metals from contaminated soil. This study was conducted to determine the potential of Ricinus communis to remove heavy metal in soil. The seedlings were planted on six different planting media T0 (100% soil-Control), T2 (80% soil + 20% sewage sludge), T3 (60% soil + 40 % sewage sludge), T4 (40% soil + 60% sewage sludge), T5 (20% soil + 80% sewage sludge) and T6 (100% sewage sludge). The highest accumulation of Mn was observed in leaves. Ricinus communis were found to be suitable as phytoremediators to clean heavy meta...

Scientific Research and Essays, Jun 15, 2014

Kenaf is an industrial crop with high potential for cultivation in a tropical climate. It is a so... more Kenaf is an industrial crop with high potential for cultivation in a tropical climate. It is a source of raw material for fiber-based industries and paper production. Considerable research has been conducted to explore its adaptability and utilization in Malaysia since 2000, under the supervision of governmental and private organizations. A number of technologies and expertise among researchers have been developed to enhance kenaf production in Malaysia. However, international documentation of the research is limited, which is important for rectification to provide a comprehensive knowledge base for all tropical and subtropical countries. The main objective of this review is to provide an overview of the results of Malaysian research on kenaf. In addition, the past, present and likely future trends in kenaf research in Malaysia as a representative tropical region are summarized.

HTML (HyperText Markup Language) merupakan bahasa asas bagi pembangunan aplikasi berasaskan web. ... more HTML (HyperText Markup Language) merupakan bahasa asas bagi pembangunan aplikasi berasaskan web. Pemahaman asas terhadap bahasa ini adalah perlu untuk membina dokumen web yang mudah. Apabila asas yang kukuh diguna pakai atau dikuasai, anda mampu membina jaringan dokumen web yang lebih rumit. Mempelajari dan menguasai HTML merupakan satu titik permulaan untuk mempersiapkan diri dengan pelbagai gelagat dalam dunia internet di masa sekarang. Buku ini menjelaskan kaedah pembinaan dokumen web menggunakan HTML dan sesuai dipelajari oleh pembaca daripada kalangan semua peringkat pendidikan.

African Journal of Agricultural Research, Aug 1, 2013

Availability of nutrients for plant uptake is directly related to soil pH and as an indicator of ... more Availability of nutrients for plant uptake is directly related to soil pH and as an indicator of soil fertility status. Determination of effects of soil amendments on soil pH should be a necessary part of fertilizer and fertility research. A pot experiment was carried out to determine and compare the effects of biochar, chicken manure, urea and zeolite on soil pH variability and elevation in a sandy loam acidic soil. A modified method was used to determine the soil pH in the pots. Soil pH in pot was measured by a glass micro-electrode and spatial variability was interpolated and mapped by using geographic information system (GIS) + software. Kriged Maps clearly showed the presence of variability and elevation in pH within each treatment. Furthermore, the position of patches with maxima and minima values for pH changed between all treatments used in the experiment. The highest elevation was found in zeolite treated soil followed by urea and biochar. However, a significant decrease was measured in soil pH in chicken dung treated soil. These findings could be the first step towards temporal stability of the pattern of spatial distribution of soil pH affected by the soil amendments (biochar, urea, chicken manure and zeolite).

For government and non-government organisations to prosper, the practice and culture of innovatio... more For government and non-government organisations to prosper, the practice and culture of innovation must be adopted. Therefore, innovation has been encouraged for each organisation by the Malaysian government since the year 2009. This paper discusses on the innovation processes in two organisations; the Science & Technology Research Institute for Defence (STRIDE), a government agency, and Celcom Axiata Berhad, a public listed company. This study is conducted based on information on innovation activities gathered from representatives from both organisations’ top managements. STRIDE, being the government’s R&D centre for defence & security, and Celcom, a telecommunications service provider, have unique ways of implementing innovations in their respective departments. This paper focuses on both organisations’ achievements with their latest innovations, their plans for the next five to ten years, and the challenges faced in maintaining and improving their performances. Organisation strat...

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2015

In this paper, a hybrid control system called as backstepping adaptive fuzzy control system, whic... more In this paper, a hybrid control system called as backstepping adaptive fuzzy control system, which integrates nominal and compensation controller is developed for autonomous quadrotor helicopter with inherent time-varying disturbance. In this hybrid control system, the nominal controller based on backstepping technique is the main controller, and the compensation controller containing a fuzzy control approach is used to eliminate the effect of uncertainties caused by external disturbance. In addition, in order to relax the requirement of prior knowledge on the bound of external disturbance, an online adaptation law is derived. Asymptotical stability of the closed-loop control system is analytically proven via the Lyapunov theorem. For the problem of determining the backstepping control parameters, particle swarm optimization algorithm has been employed. Finally, the designed controller is experimentally evaluated on a quadrotor simulation environment to demonstrate the effectiveness...

Transactions of the Institute of Measurement and Control, 2014

Designing a controller for multi-input–multi-output (MIMO) uncertain non-linear systems is one of... more Designing a controller for multi-input–multi-output (MIMO) uncertain non-linear systems is one of the most important challenging works. In this paper, the contribution is focused on the design and analysis of an intelligent adaptive backstepping control for a MIMO quadrotor helicopter perturbed by unknown parameter uncertainties and external disturbances. The design approach is based on the backstepping technique and uses a radial basis function neural network (RBFNN) as a perturbation approximator. First, a backstepping controller optimized by the particle swarm optimization is developed for a nominal helicopter dynamic model. Then, the unknown perturbations are approximated based on the universal approximation property of the RBFNN. The parameters of the RBFNN are adjusted through online learning. To improve the control design performance further, a fuzzy compensator is introduced to eliminate the approximation error produced by the neural approximator. Asymptotical stability of t...

2014 5th International Conference on Intelligent and Advanced Systems (ICIAS), 2014

ABSTRACT In this paper, a fuzzy supervisory backstepping controller (FSBC) is designed for the al... more ABSTRACT In this paper, a fuzzy supervisory backstepping controller (FSBC) is designed for the altitude and attitude stabilization of quadrotor unmanned aerial vehicle (UAV). The designed controller consists of a backstepping controller which can automatically select its parameters, on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Numerical simulations using the dynamic model of a four degree of freedom (DOF) quadrotor UAV show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor UAV with better performance than established linear design techniques.

Journal of Intelligent & Robotic Systems, 2014

ABSTRACT Quadrotor unmanned aerial vehicle (UAV) is an underactuated multi-input and multi-output... more ABSTRACT Quadrotor unmanned aerial vehicle (UAV) is an underactuated multi-input and multi-output (MIMO) system which has nonlinear dynamic behavior such as high coupling degree and unknown nonlinearities. It is a great challenge to design a quadrotor control system due to these features. In this paper, the contribution is focused on the backstepping-based robust control design of the quadrotor UAV. Firstly, the dynamic model of the aerial vehicle is mathematically formulated. Then, a robust controller is designed for the stabilization and tracking control of the vehicle. The developed robust control system comprises a backstepping and a proportional-derivative (PD) controller. Backstepping is a recursive design methodology that uses Lyapunov theorem which can guarantee the stability of the nominal model system, while PD control is used to attenuate the effects caused by system uncertainties. For the problem of determining the backstepping control parameters, particle swarm optimization (PSO) algorithm has been employed. In addition, the genetic algorithm (GA) technique is also adopted for the purpose of performance comparison with PSO scheme. Finally, the designed controller is experimentally evaluated on a quadrotor simulation environment to demonstrate the effectiveness and merits of the theoretical development.

2013 IEEE International Conference on Control System, Computing and Engineering, 2013

ABSTRACT Microfluidic devices are important for the single cell analysis such as cell mechanical ... more ABSTRACT Microfluidic devices are important for the single cell analysis such as cell mechanical and electrical characterization. Single cell characterization could be related to many significant applications including early disease diagnosis. However to perform the single cell manipulation, firstly a single cell have to be isolated and a platform for the cell manipulation have to be provided. One of the methods to trap a single cell is by using hydrodynamic trapping in the microfluidic channel. This study provides a finite element model for single cell trapping for a yeast cell model. The objectives of the simulations are to obtain the appropriate channels' geometry and optimized ratio of the fluid's inlet and suction flow rate to trap a single yeast cell. Trap channel was designed to trap a 5 µm yeast cell with a suction hole placed in the end of the trap channel. Design geometry and ratio of fluid flow rates referring to the hydrodynamic concept were studied for the cell trapping model. The analysis was carried out using numerical solutions from the finite element ABAQUS-FEA software. Using the cell trapping model, a single yeast cell able to be trapped into the trap channel with optimized channel's suction hole's geometry and appropriate fluid's inlet and suction flow rate ratio.

2011 Third International Conference on Computational Intelligence, Modelling & Simulation, 2011

... Faculty of Electrical Engineering Universiti Teknologi Malaysia 81300 Skudai, Johor, Malaysia... more ... Faculty of Electrical Engineering Universiti Teknologi Malaysia 81300 Skudai, Johor, Malaysia Centre of Artificial Intelligent and Robotics (CAIRO), Universiti Teknologi Malaysia, Jalan Semarak, 54100, Kuala Lumpur ... [16] Yuchun Tang, Yan-Qing Zhang, Nitesh V. Chawla, and ...

2011 Second International Conference on Intelligent Systems, Modelling and Simulation, 2011

In this paper, Probabilistic Neural Network with image and data processing techniques was employe... more In this paper, Probabilistic Neural Network with image and data processing techniques was employed to implement an automated brain tumor classification. The conventional method for medical resonance brain images classification and tumors detection is by human inspection. Operator-assisted classification methods are impractical for large amounts of data and are also non-reproducible. Medical Resonance images contain a noise caused by operator performance which can lead to serious inaccuracies classification. The use of artificial intelligent techniques for instant, neural networks, and fuzzy logic shown great potential in this field. Hence, in this paper the Probabilistic Neural Network was applied for the purposes. Decision making was performed in two stages: feature extraction using the principal component analysis and the Probabilistic Neural Network (PNN). The performance of the PNN classifier was evaluated in terms of training performance and classification accuracies. Probabilistic Neural Network gives fast and accurate classification and is a promising tool for classification of the tumors.

Jurnal Teknologi, 2014

Microfluidic devices are important for the single cell analysis such as cell mechanical and elect... more Microfluidic devices are important for the single cell analysis such as cell mechanical and electrical characterization. Single cell characterization could be related to many significant applications including early disease diagnosis. However to perform the single cell manipulation, firstly a single cell have to be isolated and a platform for the cell manipulation have to be provided. One of the methods to trap a single cell is by using hydrodynamic trapping in the microfluidic channel. This study provides a finite element model for single cell trapping for a yeast cell model. The objectives of the simulations are to obtain the appropriate channels’ geometry and optimized ratio of the fluid’s inlet and suction flow rate to trap a single yeast cell. Trap channel was designed to trap a 5μm yeast cell with a suction hole placed in the end of the trap channel. Design geometry and the ratio of fluid flow rates for the cell trapping model were studied using the hydrodynamic resistance con...

Jurnal Teknologi, 2011

Artikel ini membentangkan pembangunan sebuah hidung elektronik (e–Hidung) mudah alih berdasarkan ... more Artikel ini membentangkan pembangunan sebuah hidung elektronik (e–Hidung) mudah alih berdasarkan kad perolehan data National Instrument dan LabView. Kajian ini merangkumi rekabentuk litar e–Hidung yang terdiri daripada pelbagai jenis semikonduktor oksida logam daripada FIGARO sebagai sensor gas. Rintangan dari setiap sensor gas diukur melalui litar arus tetap yang dikawal melalui LabView. Sumber arus tetap digunakan sebagai antara muka elektronik bolehubah yang membolehkan pemetaan voltan keluaran sensor untuk profil rintangan sensor dilakukan secara tepat. Rintangan dari setiap sensor dikira secara tepat dan dipaparkan oleh LabView. Keputusan kajian menunjukkan bahawa e – Hidung yang dihasilkan boleh mengesan dan mengklasifikasikan antara dua jenama terkenal iaitu Body Shop dan Avon. Kaedah analisis komponen utama (PCA) yang digunakan menunjukkan diskriminasi besar iaitu 99.53% untuk bau tersebut. Ini menunjukkan bahawa sistem yang dihasilkan mampu membezakan baud an akan digunakan...