LMI Approach to Robust Unknown Input Observer Design for Continuous Systems with Noise and Uncertainties

Sharifuddin Mondal,Goutam Chakraborty,Kingshook Bhattacharyya 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.2

The full order robust unknown input observers for continuous systems are presented. The observers are designed for both linear and nonlinear systems considering both noise and uncertainties. First, an unknown input observer is designed for linear systems. The observer is derived based on linear matrix inequality (LMI) approach. Then the observer design problem is extended for a class of nonlinear systems whose nonlinear function satisfies the Lipschitz condition. The main advantage of these observers over the existing works on UIO design is that these can handle both noise and uncertainties simultaneously. The performance of the observers is demonstrated by applying it to the robust state estimation of single link robot arm.

A Fuzzy-based Adaptive Unscented Kalman Filter for State Estimation of Three-dimensional Target Tracking

Manav Kumar,Sharifuddin Mondal 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.11

Although several state estimation methods have been presented for nonlinear systems, the challenges in implementing these estimation methods for unmanned aerial vehicles (UAVs) remain due to the presence of nonlinearities, uncertainties, and complex dynamics. In this paper, an adaptive approach of unscented Kalman filter (UKF) based on fuzzy logic control (FLC) termed as fuzzy adaptive UKF (FAUKF) is proposed to enhance the state estimation performance for three-dimensional bearing-only target tracking. The measurement noise covariance is adjusted based on an adaptation law to deal with noise uncertainties. The output of the Mamdani fuzzy inference system (FIS) is used as a tuning factor in the adaptation law. The performance of the proposed method is compared with that of conventional UKF by root mean square error (RMSE) of states and the mean and standard deviation of these errors through the simulation of 500 Monte Carlo runs. The simulation results show that the FAUKF algorithm for UAVs does a much better job of estimating the state than conventional UKF and AUKF.

Simultaneous Spectrophotometric Determination of Copper, Nickel, and Zinc Using 1-(2-Thiazolylazo)-2-Naphthol in the Presence of Triton X-100 Using Chemometric Methods

Low, Kah Hin,Zain, Sharifuddin Md.,Abas, Mhd. Radzi,Misran, Misni,Mohd, Mustafa Ali Korean Chemical Society 2009 대한화학회지 Vol.53 No.6

Triton X-100이 함유된 상태에서 정색시약인 1-(2-thiazolylazo)-2-naphthol이 첨가된 물에서 구리 (II), 니켈(II)과 아연(II)의 동시 분광광도법적 정량을 위한 다변량 모델들이 개발되었다. 분광학적 간섭의 단점을 극복하기 위해서, 주성분회귀분석법(PCR)과 부분최소자승법(PLS) 다변량 분석법적 접근이 적용되었다. 다양한 시험 세트를 사용하여 본 방법의 수행이 입증되었고 그 결과들이 비교되었다. 일반적으로 PLS와 PCR 모델들 사이에 분석적 수행에서의 심각한 차이가 없었다. $Cu^{2+}$, $Ni^{2+}$ and $Zn^{2+}$ 의 세 성분들을 사용한 예측의 제곱근 평균 제곱 오차(RMSEP)들은 각각 0.018, 0.010, 0.011 ppm이었다. 또한 감도, 분석감도, 검출한계(LOD)와 같은 가치들의 측면들이 평가되었다. 본 논문에서 제안하는 과정이 화합물 혼합용액과 수돗물 속의 $Cu^{2+}$, $Ni^{2+}$ and $Zn^{2+}$의 동시 검출에 적용되었을 때에 높은 신뢰도가 성취되었다. Multivariate models were developed for the simultaneous spectrophotometric determination of copper (II), nickel (II) and zinc (II) in water with 1-(2-thiazolylazo)-2-naphthol as chromogenic reagent in the presence of Triton X-100. To overcome the drawback of spectral interferences, principal component regression (PCR) and partial least square (PLS) multivariate calibration approaches were applied. Performances were validated with several test sets, and their results were then compared. In general, no significant difference in analytical performance between PLS and PCR models. The root mean square error of prediction (RMSEP) using three components for $Cu^{2+}$, $Ni^{2+}$ and $Zn^{2+}$ were 0.018, 0.010, 0.011 ppm, respectively. Figures of merit such as sensitivity, analytical sensitivity, limit of detection (LOD) were also estimated. High reliability was achieved when the proposed procedure was applied to simultaneous determination of $Cu^{2+}$, $Ni^{2+}$ and $Zn^{2+}$ in synthetic mixture and tap water.

Preparation and characterizations of activated carbon from kenaf fiber for equilibrium adsorption studies of copper from wastewater

Zaira Zaman Chowdhury,Sharifuddin Mohd. Zain,Rashid Atta Khan,Md. Sakinul Islam 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.9

The potential of activated carbon prepared from kenaf fiber (KF) to remove copper (II) from aqueous effluents was investigated. The fibers were first semi-carbonized, then impregnated with potassium hydroxide (KOH) and finally activated by using carbon dioxide (CO2) gas to produce activated carbon. Pore structure and physical characteristics of the prepared kenaf fiber activated carbon (KFAC) were determined. Adsorption studies for divalent copper (Cu)ions were carried out to delineate the effect of contact time, temperature, pH and initial metal ion concentration on equilibrium adsorption capacity. The experimental data followed pseudo-second-order kinetics and Elovich Model than pseudo-first-order. Langmuir, Freundlich and Temkin models were implemented to analyze the parameters for adsorption at 30 oC, 50 oC and 70 oC. Thermodynamic parameters such as ΔGo, ΔHo and ΔSo which represent Gibbs free energy,enthalpy and entropy, respectively, were evaluated. It was concluded that activated carbon from kenaf fiber (KFAC)can be used as an efficient adsorbent for removal of Cu (II) from synthetic wastewater.

The Utilisation of Pisang Island as a Platform to Support the Current Safety and Security Needs of Marine Navigation in the Straits of Malacca

Ahmad Faizal AHMAD FUAD,Mohd Sharifuddin AHMAD,Mohd Naim FADZIL,Noor Apandi OSNIN 국제이네비해양경제학회 2017 International Journal of e-Navigation and Maritime Vol.7 No.1

Current marine navigational practice relies less on long-range visual marine signals such as lighthouses for reference purposes. This is due to the availability of Global Navigation Satellite Systems (GNSS), which are integrated with other navigational aids on ships. Therefore, the objective of this study is to review the function of Pisang Island lighthouse and to propose the most relevant use of Pisang Island for current navigational needs. The function of the lighthouse was reviewed according to the IALA Navigational Guide and the AIS data image. The result showed that the most suitable navigational use of the lighthouse is to act as a reference for Line of Position (LOP). The AIS data image indicated that mariners are not using Pisang Island lighthouse for LOP. The trend in the Straits of Malacca (SoM) was compared with the trend in the Straits of Dover, UK. The selected experts verified that LOP was not practised there. As a specific example, a tanker ship route in the South China Sea was used to further support that LOP was not practised. This evidence supported the view that Pisang Island lighthouse is less relevant for current navigational practice and does not directly support the coastal state VTS operation and the establishment of the marine electronic highway. Furthermore, the existing shore-based VTS radar has limitations on range and the detection of targets near Pisang Island. Therefore, this study proposes the establishment of a new radar station on Pisang Island at the existing site of the lighthouse. The proposed new radar station on Pisang Island will add to the existing coverage of the VTS radar, bridging the coverage gaps to overcome the weakness of the existing shore-based radar and improve the safety and security of marine navigation in the SoM.

Effect of Unsaturation on the Stability of C₁₈ Polyunsaturated Fatty Acids Vesicles Suspension in Aqueous Solution

Teo, Yin Yin,Misran, Misni,Low, Kah Hin,Zain, Sharifuddin Md. Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

Degree of unsaturation in fatty acid molecules plays an important role in the formation of vesicles. Vesicle formation from C18 fatty acids with different amount of double bonds such as oleic acid, linoleic acid and linolenic acid with the incorporation of 1,2-dipalmitoyl-sn-glycerol-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DPPE-PEG2000) have been examined by TEM. Critical vesicular concentrations (CVC) of the vesicle suspension are determined by turbidity and surface tension methods. The CVC of fatty acids increases when the amount of unsaturation in the alkyl chain increases. On the other hand, stability of vesicle suspension has been examined by using particle size and zeta potential at $30^{\circ}C$. There was a dramatic decrease in particle size measurement from mono-unsaturation to tri-unsaturation which could be due to the effect of fluidity in the membrane bilayer caused by different degree of unsaturation. The values of zeta potential for vesicles that were formed without the incorporation of DPPE-PEG2000 were in the range of -70 mV to -100 mV. It has been observed that the incorporation of DPPEPEG2000 to the vesicle reduces the magnitude of zeta potential. However, this phenomenon does not obviously seen in fatty acid vesicles formed by linoleate-linoleic acid and linolenate-linolenic acid. We therefore conclude that the addition of DPPE-PEG2000 does not effectively improve the stability of the linoleate-linoleic acid and linolenatelinolenic acid vesicle at pH 9.0 after the evaluation of their particle size and zeta potential over a period of 30 days. Although the vesicles formed were not stable for more than 10 days, they have displayed the potential in encapsulating the active ingredients such as vitamin E and calcein. The results show that the loading efficiencies of vitamin E are of encouraging value.

Preliminary Studies on Embedding Qualitative Reasoning into Qualitative Analysis and Laboratory Simulation

Jen Sen Pang,S.M.F.D Syed Mustapha,Sharifuddin Mohd. Zain 한국지능정보시스템학회 2001 한국지능정보시스템학회 기타 간행물 Vol.- No.-

Effect of Unsaturation on the Stability of C_18 Polyunsaturated Fatty Acids Vesicles Suspension in Aqueous Solution

Yin Yin Teo,Misni Misran,Kah Hin Low,Sharifuddin Md. Zain 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

Degree of unsaturation in fatty acid molecules plays an important role in the formation of vesicles. Vesicle formation from C18 fatty acids with different amount of double bonds such as oleic acid, linoleic acid and linolenic acid with the incorporation of 1,2-dipalmitoyl-sn-glycerol-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000](DPPE-PEG2000) have been examined by TEM. Critical vesicular concentrations (CVC) of the vesicle suspension are determined by turbidity and surface tension methods. The CVC of fatty acids increases when the amount of unsaturation in the alkyl chain increases. On the other hand, stability of vesicle suspension has been examined by using particle size and zeta potential at 30 ^oC. There was a dramatic decrease in particle size measurement from mono-unsaturation to tri-unsaturation which could be due to the effect of fluidity in the membrane bilayer caused by different degree of unsaturation. The values of zeta potential for vesicles that were formed without the incorporation of DPPE-PEG2000 were in the range of ‒70 mV to ‒100 mV. It has been observed that the incorporation of DPPEPEG2000to the vesicle reduces the magnitude of zeta potential. However, this phenomenon does not obviously seen in fatty acid vesicles formed by linoleate-linoleic acid and linolenate-linolenic acid. We therefore conclude that the addition of DPPE-PEG2000 does not effectively improve the stability of the linoleate-linoleic acid and linolenatelinolenic acid vesicle at pH 9.0 after the evaluation of their particle size and zeta potential over a period of 30 days. Although the vesicles formed were not stable for more than 10 days, they have displayed the potential in encapsulating the active ingredients such as vitamin E and calcein. The results show that the loading efficiencies of vitamin E are of encouraging value.

SESSION 5 - SOIL FERTILITY MANAGEMENT : Sustaining Crop Production on Acid Tropical Soils Through Limestone and Gypsum Applications

( J . Shamshuddin S . R . Syed Omar,H . A . H . Sharifuddin ) 한국토양비료학회 1997 Soil Quality Management and Agro-Ecosystem Health Vol.- No.-

Factors influencing Malaysian Maritime Industry in Remaining Sustainable in Global Trade

R. Md HANAFIAH,Kasypi MOKHTAR,Masha MENHAT,Izyan Munirah MOHD ZAIDEEN,Juhaizi MOHD YUSOF,Norhafiza Ilyana YATIM,Mohd Sharifuddin AHMAD 국제이네비해양경제학회 2020 International Journal of e-Navigation and Maritime Vol.14 No.1

Maritime sector has played a critical role for the growth and development of the Malaysia in facilitating global trade. Malaysia rely on the sector for the import and export of goods as around 90% of the nation trade is carried through maritime transportation. Although there are increasing in trade performance, Malaysian maritime industry is still facing a hard times to safeguard Malaysia's economic interests and to retain its competitive advantage as a leading maritime nation. Therefore, this paper aims to identify, analyses and evaluate the factors that influencing Malaysian maritime industry in remaining sustainable in global trade. In order to explain how the influencing factors affect the Malaysian maritime industry, a systematic hierarchical structure was developed. Then, by employed Analytical Hierarchy Process (AHP) technique, the priorities among various criteria was determined through the judgments of experts using a set of scales. The results of this study will assist the shipping entities to cope with those challenges and for Malaysia maritime sector to remain a key enabler of international trade.