Universiti Teknologi Malaysia Institutional Repository: No conditions. Results ordered -Date Deposited. 2023-09-29T20:24:47ZEPrintshttp://eprints.utm.my/images/sitelogo.gifhttp://eprints.utm.my/id/eprint/2017-08-02T07:25:13Z2017-08-02T07:25:31Zhttp://eprints.utm.my/id/eprint/id/eprint/32368This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/323682017-08-02T07:25:13ZPembangunan reaktor DC PECVD dan kajian struktur filem tipis karbon amorfus terhidrogen (a-C:H)Putut Marwoto2014-11-02T02:37:48Z2017-09-25T12:51:42Zhttp://eprints.utm.my/id/eprint/id/eprint/42542This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425422014-11-02T02:37:48ZSynthesis, catalytic activity measurement and characterization of doped cobalt oxide catalysts for toxic gases emission treatment Swee Kuan Yen 2014-11-02T02:37:48Z2014-11-02T02:37:48Zhttp://eprints.utm.my/id/eprint/id/eprint/42545This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425452014-11-02T02:37:48ZTechnique development of a headspace solid-phase microextraction-gas chromatography (SPME-GC) for the forensic analysis of ignitable liquid residues in fire debris Teik Yau Yong 2014-11-02T02:37:47Z2014-11-02T02:37:47Zhttp://eprints.utm.my/id/eprint/id/eprint/42303This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423032014-11-02T02:37:47ZAcid-base properties of modified zeolite beta : modification, characterization and catalytic testing Kah Man Wong 2014-11-02T02:37:45Z2017-09-25T02:56:13Zhttp://eprints.utm.my/id/eprint/id/eprint/42505This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425052014-11-02T02:37:45ZPurification and characterization of glucoamylase from amylomyces rouxii Kian Chuan Sia 2014-11-02T02:37:45Z2017-09-25T12:45:37Zhttp://eprints.utm.my/id/eprint/id/eprint/42538This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425382014-11-02T02:37:45ZStudy on genetic algorithm and heuristic method for solving traveling salesman problem San Nah Sze 2014-11-02T02:37:42Z2020-08-30T04:06:53Zhttp://eprints.utm.my/id/eprint/id/eprint/42370This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423702014-11-02T02:37:42ZDyTAS : discrete event simulation model for dynamic task scheduling Syarifah Zyurina Nordin2014-11-02T02:37:41Z2017-09-25T10:52:24Zhttp://eprints.utm.my/id/eprint/id/eprint/42519This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425192014-11-02T02:37:41ZSinThesis ketohidrazon dan penggunaannya sebagai reagen dalam analisis spektrofluorimetri aluminium (III) Abdul Malik Muhammad Nur2014-11-02T02:37:40Z2020-08-25T07:35:49Zhttp://eprints.utm.my/id/eprint/id/eprint/42290This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/422902014-11-02T02:37:40ZMathematical models for free and mixed convection boundary layer flows of micropolar fluids Roslinda Mohd Nazar2014-11-02T02:37:36Z2020-08-30T01:30:38Zhttp://eprints.utm.my/id/eprint/id/eprint/42336This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423362014-11-02T02:37:36ZCliqCoNet : a visual simulation model for partitioning nodes in static ad hoc networks Leh Yieng Kiew 2014-11-02T02:37:36Z2017-09-23T04:25:56Zhttp://eprints.utm.my/id/eprint/id/eprint/42480This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/424802014-11-02T02:37:36ZPenyediaan dan pencirian komponen berpendafluor melalui teknik pengkompleksan logam-logam Hazmimi Kasim2014-11-02T02:37:35Z2014-11-02T02:37:35Zhttp://eprints.utm.my/id/eprint/id/eprint/42482This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/424822014-11-02T02:37:35ZPenyediaan, pencirian dan ujian keberkesanan TiQ2 berpenyokong melalui kaedah elektro pemendapan sebagai fotomangkin terhadap Pewarna Sumifix Supra Biru (SSB) Ira Dwiyanti Jumari2014-11-02T02:37:34Z2014-11-02T02:37:34Zhttp://eprints.utm.my/id/eprint/id/eprint/42315This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423152014-11-02T02:37:34ZAplikasi biofilem dalam penyingkiran warna dan logam berat daripada air sisa tekstil Aishah Husin2014-11-02T02:37:34Z2017-09-23T02:54:14Zhttp://eprints.utm.my/id/eprint/id/eprint/42462This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/424622014-11-02T02:37:34ZPenentuan pestisid organofosforus menggunakan teknik voltammetri dengan elektrod pasta karbon dan elektrod cetakan skrin Hasuhana Hamid2014-11-02T02:37:33Z2014-11-02T02:37:33Zhttp://eprints.utm.my/id/eprint/id/eprint/42301This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423012014-11-02T02:37:33ZA simulation study of the Korteweg - dE Vries - Burgers Equation Yee Ming Chew 2014-11-02T02:37:32Z2014-11-02T02:37:32Zhttp://eprints.utm.my/id/eprint/id/eprint/42323This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423232014-11-02T02:37:32ZApplications of Fe(III) leaching and biooxidation for the recovery of Au from refractory gold ores Mohammad Azri Bunyok2014-11-02T02:37:31Z2017-09-23T06:07:19Zhttp://eprints.utm.my/id/eprint/id/eprint/42495This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/424952014-11-02T02:37:31ZPreparation, bromination and reduction of meso-tetraphenylporphyrin Mohd. Bakri Bakar2014-11-02T02:37:31Z2017-09-25T13:07:50Zhttp://eprints.utm.my/id/eprint/id/eprint/42553This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425532014-11-02T02:37:31ZThe effect of artificial destratification on the fate of iron and manganese in a tropical reservoir Noor Halini Baharim2014-11-02T02:37:30Z2014-11-02T02:37:30Zhttp://eprints.utm.my/id/eprint/id/eprint/42368This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423682014-11-02T02:37:30ZDiagnostic of laser plasma using optical techniques Ahmad Hadi Ali2014-11-02T02:37:29Z2014-11-02T02:37:29Zhttp://eprints.utm.my/id/eprint/id/eprint/42387This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/423872014-11-02T02:37:29ZFrecast : message transmission model for ad hoc networks Sakhinah Abu Bakar2014-11-02T02:37:29Z2020-09-13T03:21:48Zhttp://eprints.utm.my/id/eprint/id/eprint/42568This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/425682014-11-02T02:37:29ZUjian kesahihan jangkaan kadar dos sinar gama daratan dan kajian implikasi radiologi persekitaran di daerah Kota Tinggi, Johor, MalaysiaAhmad Taufek Abdul Rahman2012-11-23T08:46:26Z2017-03-07T08:50:34Zhttp://eprints.utm.my/id/eprint/id/eprint/533This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/5332012-11-23T08:46:26ZPlasma formation induced by a Q-switched Nd:YAG laserLight energy can create a plasma when high irradiance is focused. This proeess of opticical breakdown can be achieved by using a Q-switched laser. In this paper, we report the application of a high-power Nd:YAG laser to generate plasma. Two different techniques were conducted to generate optical breakdown and initiate the plasma. In the first technique the laser was diverged by a negative lens and brought to focus by a wide-angle camera lens of 28 mm focal length. Secondly, the same concave lens was employed to expand the beam but converged back by using a longer focal length of 50 mm. The plasma formation from both focusing systems are visualized and recorded via CCD video camera in conjunction with a high-speed photography system. The recorded images were analyzed using the Matrox Inspector version 2.1 software. The maximum plasma length obtained from short and long focal length system are 1.193 ± 0.060 mm and 2.815 ± 0.141 mm respectively. Nevertheless, both techniques produced broadly elliptical shape of plasma and exponentially expand with respect to the increasing of laser power.Ahmad Hadi AliNoriah Bidin2012-09-18T06:09:28Z2022-01-31T08:37:52Zhttp://eprints.utm.my/id/eprint/id/eprint/28193This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/281932012-09-18T06:09:28ZMolecular identification of Candida tropicalis RETL-Cr1 By PCR amplification of Ribosomal DNAPCR amplification of ribosomal DNA was used to identify a phenol-degrading yeast strain. Theinternal transcribed spacer regions of the yeast was amplified using universal primers ITSI and ITS4. Based on a BLASTN search of genBank, the complete sequences of ITSI-%.*S rDNA-ITS2 regions and portions of 18S and 28S for the purified DNA products of RETL-Crl shared 98% similarity with Candida tropicalis. The nucleotide swquences of the C. tropicalis RETL-Crl was submitted to the GenBank database under the accession number AY725426.Aishah HusinPiakong Mohd. TuahNoor Aini Abdul RashidAdibah YahyaMadihah Md. SallehSharifah Norhafizah Syed Mohd. Rafeii2012-05-30T08:32:51Z2012-10-04T08:56:51Zhttp://eprints.utm.my/id/eprint/id/eprint/13654This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/136542012-05-30T08:32:51ZThe chemical constituents and bioactivity studies of four Vitex species and PhyllanthusWatsoniChoon Ling Wong2012-05-30T04:43:16Z2012-05-30T08:50:02Zhttp://eprints.utm.my/id/eprint/id/eprint/13586This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/135862012-05-30T04:43:16ZPenyelesaian gelombang solitari bagi persamaan jenis Korteweg-de VriesJusoh Yacob2011-07-06T01:49:33Z2017-11-01T04:17:38Zhttp://eprints.utm.my/id/eprint/id/eprint/12883This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/128832011-07-06T01:49:33ZElasticity measurement using holographic interferometry double exposure techniqueHolographic measurement of modulus elasticity was performed on samples of aluminum can. It is based upon the measurement of the displacement as a function number of fringes appeared on the body of the loaded can. The value of the modulus elasticity for the aluminum can is obtained as (1.00 ± 0.03) × 108 nm–2. This result is found in good agreement with a mechanical measurement by taking into account any experimental errorKua Hock ChuanNoriah Bidin2011-07-06T01:48:18Z2017-11-01T04:17:38Zhttp://eprints.utm.my/id/eprint/id/eprint/12885This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/128852011-07-06T01:48:18ZA visual tool for determining the maximum independent set of a graph using the polynomial formulation methodMaximum independent set is a prototype problem in a graph theory that has many applications in engineering and science. In this paper, we study the problem of determining the largest number of maximum independent sets of a graph G (V, E) of order n using polynomial formulations. This method uses the first and second order neighbourhoods of nodes to determine whether a node is in the maximum independent set. This involves the maximization of an n-variable polynomial, where n is the number of nodes in G. Finally, we present a visual tool developed using the Visual C++ programming language for solving the maximum independent set problem.Wan Heng FongShaharuddin Salleh2011-07-06T01:43:28Z2017-11-01T04:17:38Zhttp://eprints.utm.my/id/eprint/id/eprint/12887This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/128872011-07-06T01:43:28ZDesign of educational software for automatic speech recognition (asr) techniquesSpeech recognition has been an important subject for research, and it has come to a stage where it has been actively applied in a lot of industrial and consumer applications, overseas. However, speech recognition research is still in its infancy stage in Malaysia. The main reason is that speech recognition systems are highly complex and teaching students in this subject matter with the underlying technologies is a challenging task. Currently, some instructors use slide show presentations and white board in giving such courses. At the end of the course, students are not able to figure out the real output of the algorithms given. In this case, students are not exposed to the real technical systems and would easily get bored. This research is mainly on the improvement over the limitations and problems of the traditional teaching method in speech recognition by developing a set of interactive and practical education software to guide and assist students in studying, and performing experiments for speech recognition.Kai Sze HongSheikh Hussain Shaikh Salleh2011-06-30T05:32:33Z2018-03-12T01:42:36Zhttp://eprints.utm.my/id/eprint/id/eprint/12808This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/128082011-06-30T05:32:33ZThe effect of varying process parameters on the Microhardness and Microstru Cu-steel and Al-Al2o3 friction jointsVarying the rotational speed and forging pressures during friction welding affect the joint properties differently. C11000 copper to AISI 1030 mild steel (Cu-steel), and 6061 aluminum to alumina (Al-Al2O3) friction joints were fabricated on a direct drive friction welding machine. Microhardness traverses across the joint showed lower copper hardness, and higher steel hardness compared to the parent material, when 900 rpm rotational speed as used. This trend is reversed when the rotational speed is increased to 1800 rpm. Grain structure distortation was confined to an area of < 0.5 mm from the joint interface. Microhardness traverses across the Al-Al2O3 joint could not yield much information due to the influence of porosity on the microhardness readings. The results indicate that microhardness test is not appropriate for the characterization of Al-Al2O3 friction joints.Cheow Keat YeohShamsul Baharin JamaludinZainal Arifin Ahmad2011-06-30T02:05:14Z2017-02-08T01:07:48Zhttp://eprints.utm.my/id/eprint/id/eprint/12797This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/127972011-06-30T02:05:14ZThe basicity and acidity of beta zeolites after ion-exchange with alkali metal cations: a physicochemical characterizationThe structure, basicity and acidity properties of the alkali metals (Na, K and Cs) exchanged zeolite beta were investigated in this work. Infrared (IR) and X-ray diffraction (XRD) were used for structural characterizations, while Temperature programmed desorption of CO2 and NH3 were use for the determination of basicity and acidity, respectively. Results reveal that the framework structure of zeolite beta is retained after the exchange but with a successive decrease in the relative crystallinity after the modification. The acidity of zeolite beta has decreased significantly with the decrease in the crystallinity. However, the basicity after the exchange was not very significant in comparison to the acidity. The effect of the crystallinity and the type of alkali metal cations on basicity is also shown.Kah Man WongNur HadiAbdul Rahim YacobZainab Ramli2011-05-19T06:52:11Z2011-07-22T08:20:19Zhttp://eprints.utm.my/id/eprint/id/eprint/12339This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/123392011-05-19T06:52:11ZStructural phase transition of boron nitride compoundThe full-potential band-structure scheme based on the linear combination of overlapping nonorthogonal local-orbital (FPLO) is used. The crystal potential and density are represented as a lattice sum of local overlapping nonspherical contributions. The energetic transitions of BN of zinc-blende and wurtzite structures are calculated using the band structure scheme. The energy gap at ambient pressure is found to be indirect for the two structures. The structural properties of two structures of BN are (obtained from the total energy calculations) and the total density of states are calculated. The phase transition parameter of BN is investigated. The ionicity character of BN has been calculated to test the validity of our recent models. The results are in reasonable agreement with experimental and other theoretical results.Yal Al-Douri2011-03-29T04:24:47Z2011-07-22T08:16:11Zhttp://eprints.utm.my/id/eprint/id/eprint/12198This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/121982011-03-29T04:24:47ZExplicit methods in solving stiff ordinary differential equationsIn this article, we extended the existing explicit Taylor method and modified it to gain a new explicit Taylor-liked method in solving stiff differential equations. We also considered the stability property for this method since the stability property of the classical explicit fourth order Runge-Kutta (RK4) method is not adequate for the solution of stiff problems. Implicit methods could work well for stiff problems but have certain drawbacks especially when discussing about the cost. A comparison of the existing implicit Adam-Bashforth, the classical explicit (RK4) and the new explicit Taylor-liked method is presented. R. R. AhmadNazeeruddin YaacobAli Hassan Mohamed Murid2011-03-23T00:29:05Z2017-10-08T04:54:53Zhttp://eprints.utm.my/id/eprint/id/eprint/12180This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/121802011-03-23T00:29:05ZA simple more general boxplot method for identifying outliersThe boxplot method (Exploratory Data Analysis, Addison-Wesley, Reading, MA, 1977) is a graphically-based method of identifying outliers which is appealing not only in its simplicity but also because it does not use the extreme potential outliers in computing a measure of dispersion. The inner and outer fences are defined in terms of the hinges (or fourths), and therefore are not distorted by a few extreme values. Such distortion could lead to failing to detect some outliers, a problem known as "masking". A method for determining the probability associated with any fence or observation is proposed based on the cumulative distribution function of the order statistics. This allows the statistician to easily assess, in a probability sense, the degree to which an observation is dissimilar to the majority of the observations. In addition, an adaptation for approximately normal but somewhat asymmetric distributions is suggested.Neil C. SchwertmanMargaret Ann OwensRobiah Adnan2010-04-02T03:54:20Z2017-04-10T08:13:45Zhttp://eprints.utm.my/id/eprint/id/eprint/9832This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/98322010-04-02T03:54:20ZUnsteady boundary layer flow in the region of the stagnation point on a stretching sheetUnsteady two-dimensional stagnation point flow of an incompressible viscous fluid over a flat deformable sheet is studied when the flow is started impulsively from rest and the sheet is suddenly stretched in its own plane with a velocity proportional to the distance from the stagnation point. After a similarity transformation, the unsteady boundary layer equation is solved numerically using the Keller-box method for the whole transient from τ=0 to the steady state τ→∞. Also, a complete analysis is made of the governing equation at τ=0, the initial unsteady flow, at large times τ=∞, the steady state flow, and a series solution valid at small times τ (≪1). It is found that there is a smooth transition from the initial unsteady state flow (small time solution) to the final steady state flow (large time solution).Roslinda NazarNorsarahaida AminDiana FilipIoan Pop2009-05-12T08:34:33Z2017-10-11T01:56:29Zhttp://eprints.utm.my/id/eprint/id/eprint/8800This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/88002009-05-12T08:34:33ZPemetaan konformal daerah banyak segi melalui persamaan kamiran terhadap Inti Bergman dan Inti Szego.A numerical method is described for computing conformal mapping from a simply connected region with corners onto the unit disk. The numerical method is based on the Fredholm integral equations for Bergman and Szego kernels. The numerical method for solving the integral equations is based on the Nystrom method with trapezoidal rule.
Baharudin HurminAli Hassan Mohamed Murid2009-05-12T08:28:24Z2017-10-11T01:56:42Zhttp://eprints.utm.my/id/eprint/id/eprint/8799This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/87992009-05-12T08:28:24ZA branch and bound and simulated annealing approach for job shop schedulingThis paper presents two approaches to the solution of the job shop scheduling problem, namely the branch and bound, and simulated annealing approach. The objective is to schedule the jobs on the machines so that the total completion time is minimized. In the branch and bound approach, the job shop scheduling problem is represented by a disjunctive graph, then the optimal schedule is obtained using the branch and bound algorithm while simulated annealing is a local search based algorithm which will slightly perturb the initial feasible solution to decrease the makespan.
Hui Woon TanSutinah Salim2009-05-12T08:21:19Z2017-10-11T01:56:05Zhttp://eprints.utm.my/id/eprint/id/eprint/8798This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/87982009-05-12T08:21:19ZGlimpse on the relationship between Feynman integral and integrable systemWe briefly review recent attempts to relate the concept of Feynman integral and integrable systems. This constitutes an endeavour on our part in making the Feynman path integral into a mathematically meaningful entity.Zainal Abdul Aziz2009-03-16T06:35:45Z2018-09-19T05:07:11Zhttp://eprints.utm.my/id/eprint/id/eprint/7997This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/79972009-03-16T06:35:45ZSome characterizations of groups of order 8Group theory is a branch of mathematics which concerns with the study of groups. It has wide applications in other fields too including chemistry. This research focuses on groups of order 8 and their irreducible representations. There are five groups of order 8, namely 0 4 , Q, C8, C2 x C4 and C2 x C2 x C2. For any group, the number of possible representative sets of matrices is infinite, but they can all be reduced to a single fundamental set, called the irreducible representations of the group. Burnside method and Great Orthogonality Theorem method are both used to obtain irreducible representations of all groups of order 8. Then, comparisons of both methods are made. Irreducible representation is actually the nucleus of a character table and is of great importance in chemistry. Groups of order 8 are isomorphic to certain point groups. Point groups are symmetry groups which leave at least one point in space fixed under all operations. In this research, isomorphisms from four out of five groups of order 8, namely 0 4 , C8, C2 x C4 and C2 x C2 x C2, and isomorphisms from proper subgroups of Q to certain point groups are determined.Wan Heng Fong2009-03-16T06:35:25Z2018-09-19T05:07:12Zhttp://eprints.utm.my/id/eprint/id/eprint/7999This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/79992009-03-16T06:35:25ZAn exploratory study on goal programming as an alternative method to develop prediction equationsOne of the most promising techniques for multiple objective decision analysis is goal programming. Goal programming is a powerful tool which draws upon the highly developed and tested technique of linear programming, but provides a simu~taneousolution to a complex system of competing objectives. Least squares method in regression analysis is also a popular technique used in decision making. It is an approach used in the study of relations between variables, particularly for the purpose of understanding how one variable depends on one or more other variables. However, one of the main problems is that the method of least squares is biased by extreme cases. This study proposes goal programming as an alternative to analyze such problems. The analysis were done by using QM for Windows and MINITAB software package.Chik Kong Lau2009-03-16T06:34:50Z2018-09-19T05:07:14Zhttp://eprints.utm.my/id/eprint/id/eprint/8002This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/80022009-03-16T06:34:50ZMathematical models for the boundary layer flow due to a moving flat plateThe boundary-layer flow over a moving continuous solid surface is important in several engineering processes. For example, materials manufactured by extrusion processes and heat-treated materials travelling between a feed roll and a wind-up roll or on conveyor belt possess the characteristics of a moving continuous surface. In this study, the mathematical model for a boundary layer flow due to a moving flat plate in micropolar fluid is discussed. The plate is moving continuously in the positive x -direction with a constant velocity. The governing boundary layer equations are solved numerically using an implicit finite difference scheme. Numerical results presented include the reduced velocity profiles, gyration component profiles and the development of wall shear stress or skin friction for a wide range of material parameter K takes the values, K = 0,0.1,0.3,0.5, 1,3, 5 and 10. The results obtained, when the material parameter K = 0 (Newtonian fluid), are in excellence agreement with those obtained for viscous fluids. Further, the wall shear stress increases with increasing K . For fixed K, the wall shear stress decreases and the gyration component increases with increasing values of n , in the range 0 I n I 1 where n is a ratio of the gyration vector component and the fluid shear stress at the wall.Mohd. Zuki Salleh2009-03-16T06:34:12Z2018-09-19T05:07:15Zhttp://eprints.utm.my/id/eprint/id/eprint/8006This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/80062009-03-16T06:34:12ZFormal language theory and DNAFormal language theory is a branch of applied group theory that is denoted to the study of finite strings called language over some symbols chosen from a prescribed finite set called alphabet. A new manner of relating formal language theory to the study of informational macromolecules is initiated. A language is associated with each pair of sets where the first set consists of double-stranded DNA molecules and the second set consists of the recombinational behaviors allowed by specified classes of enzymatic activities. The scope of this research is on the potential effect of sets of restriction enzymes and ligase that allow DNA molecules to be cleaved and reassociated to produce further molecules. The associated languages are analysed by means of a new generative formalism called a splicing system. Splicing systems were originally developed as a mathematical or dry model of the generative of DNA molecules in the presence of appropriate restriction enzymes and a ligase. A significant subclass of these languages, which we call the persistent splicing languages, is shown to coincide with a class of regular languages which have been previously study in other contexts: the strictly locally testable languages. The relationship between the family SH of simple splicing language and the family of strictly locally testable languages is clarified. This study initiates the formal analysis of the generative power of recombinational behaviors in general. The splicing system formalism allows observations to be made concerning the generative power of general recombination and also of sets of enzymes that include general recombination.Nor Muhainiah Mohd. Ali2009-01-22T07:20:40Z2011-03-22T04:51:23Zhttp://eprints.utm.my/id/eprint/id/eprint/7803This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/78032009-01-22T07:20:40ZDichloromethyl[1-(2-pyridyl)ethanone benzoylhydrazonato]tin(IV)The chelate Sn - O - C - N - N - C - C - N fragment, together with the substituent methyl C atom, in the title complex, [SnCl2(CH 3)(C14H12N3O)], is planar, allowing the tridentate O,N,N-donor atoms and the methyl ligand C atom to occupy the equatorial positions in an octahedral environment. The geometry of the Sn atom is distorted octahedral, with a Cl - Sn - Cl axial bond angle of 172.02 (3)Â°.M.A AffanM.B ShamsuddinM. S M Yusof2009-01-12T00:37:30Z2017-10-11T01:24:14Zhttp://eprints.utm.my/id/eprint/id/eprint/6860This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/68602009-01-12T00:37:30ZHigh temperature liquid chromatography of triazole fungicides on polybutadiene-coated zirconia stationary phaseHigh temperature liquid chromatography using water-rich and superheated water eluent is evaluated as a new approach for the separation of selected triazole fungicides, hexaconazole, tebuconazole, propiconazole, and difenoconazole. Using a polybutadiene-coated zirconia column at temperatures of 100â€“150 oC, clear separations were achieved when 100% purified water was utilized as organic-free eluent. Excellent limits of detection down to pg level were obtained for the separation of the triazole fungicides under optimum conditions. Vanâ€™t Hoff plots for the separations were linear suggesting that no changes occurred in the retention mechanism over the temperature range studied.M. Marsin SanagiH. H. SeeWan Aini Wan IbrahimAhmedy Abu Naim2009-01-06T03:41:48Z2017-02-15T00:20:51Zhttp://eprints.utm.my/id/eprint/id/eprint/7481This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/74812009-01-06T03:41:48ZQuantitative measurement of a mixture of mesophases cubic MCM-48 and hexagonal MCM-41 by 13C CP/MAS NMR.
Quantitative measurement of a mixture of cubic MCM-48 and hexagonal MCM-41 mesophases by means of 13C CP/MAS NMR was discussed. The synthesis of pure cubic MCM-48, pure hexagonal MCM-41 and mixed hexagonal-cubic phases were carried out via mixed cationic-neutral templating route. The result show that in a mixture of hexagonal-cubic phase the presence of MCM-48 at a certain level could not be identified by XRD due to the very weak reflections. The result also show that the technique can be applied to a wide range of mesoporous structures.Hadi NurLau Chin GuanSalasiah EndudHalimaton Hamdan2009-01-02T01:26:50Z2009-01-02T01:26:50Zhttp://eprints.utm.my/id/eprint/id/eprint/7261This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/72612009-01-02T01:26:50ZUnsteady boundary layer flow due to a stretching surface in a rotating fluid The induced unsteady flow due to a stretching surface in a rotating fluid, where the unsteadiness is caused by the
suddenly stretched surface is studied in this paper. After a similarity transformation, the unsteady Navierâ€“Stokes
equations have been solved numerically using the Keller-box method. Also, the perturbation solution for small times as well as the asymptotic solution for large times, when the flow becomes steady, has been obtained. It is found that there is a smooth transition from the small time solution to the large time or steady state solutionRoslinda NazarNorsarahaida AminIoan Pop2009-01-02T01:22:37Z2009-01-02T01:22:37Zhttp://eprints.utm.my/id/eprint/id/eprint/7208This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/72082009-01-02T01:22:37ZUnsteady mixed convection boundary layer flow near the stagnation point on a vertical surface in a porous mediumThe unsteady mixed convection boundary layer flow near the region of a stagnation point on a vertical surface embedded in a Darcian fluid-saturated porous medium is studied in this paper. It is assumed that the unsteadiness is caused by the impulsive motion of the free stream velocity and by sudden increase in the surface temperature. The problem is reduced to a single partial differential equation, which is solved numerically using the Kellerâ€“Box method. The small time (initial unsteady flow) as well as the large time (final steady state flow) solutions are also included in the analysis. The asymptotic behavior of the solution for small and large values of the mixed convection parameter Î» is also examined when the flow becomes steady. It is shown that there is a smooth transition from the small time solution to the large time solution. It is also shown that there is an excellent agreement between the numerical and analytical solutions. The uniqueness of this problem lies on the fact that we have been able to show that in the case of steady state flow, solutions are possible for all values of Î»>0 (assisting flow) and for Î»<0 (opposing flow), solutions are possible only for a limited range of Î»Roslinda NazarNorsarahaida AminIoan Pop2009-01-02T01:19:20Z2011-03-29T04:07:15Zhttp://eprints.utm.my/id/eprint/id/eprint/7249This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/72492009-01-02T01:19:20ZMixed convection boundary-layer flow from a horizontal circular cylinder with a constant surface heat fluxThe laminar mixed convection boundary-layer
flow of a viscous and incompressible fluid past a horizontal circular cylinder, which is maintained at a constant heat flux and is placed in a stream flowing vertically upward has been theoretically studied in this paper. The solutions for the flow and heat transfer characteristics are evaluated numerically for different values of the mixed convection parameter k with the Prandtl number Pr = 1 and 7, respectively. It is found, as for the case of a heated or cooled cylinder, considered by Merkin [5], that assisting flow delays separation of the boundary-layer and can, if the assisting flow is strong enough, suppress it completely. The opposing flow, on the other side, brings the separation point nearer to the lower stagnation point and for sufficiently strong opposing flows there will not be a boundary-layer on the cylinderRoslinda NazarNorsarahaida AminIoan Pop2009-01-02T01:11:58Z2009-01-02T01:11:58Zhttp://eprints.utm.my/id/eprint/id/eprint/7244This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/72442009-01-02T01:11:58ZStagnation point flow of a micropolar fluid towards a stretching sheet The steady two-dimensional stagnation point flow of an incompressible micropolar fluid over a stretching sheet when the sheet is stretched in its own plane with a velocity proportional to the distance from the stagnation point, has been studied in this paper. The resulting equations of non-linear ordinary coupled differential equations are solved numerically using the Kellerâ€“box method. The results obtained for velocity, microrotation and skin friction are shown in tables and graphs. Comparison with the recent results of Mahapatra and Gupta {Heat Mass Transfer 38 (2002) 517} for the corresponding problem of a viscous fluid (K=0) has been done and it has been shown that the results are in excellent agreementRoslinda NazarNorsarahaida AminDiana FilipIoan Pop2009-01-01T04:41:12Z2010-06-01T15:50:17Zhttp://eprints.utm.my/id/eprint/id/eprint/7239This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/72392009-01-01T04:41:12ZProduction of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. TS1-1: Media optimization using experimental design
Cyclodextrin glucanotransferase (CGTase) was produced when the Bacillus sp. TS1-1 was grown in a medium containing sago starch, yeast extract, phosphorus and mineral salt sources, using shake flask mode at 37Â°C for 24 h. Response surface methodology (RSM) was applied to optimize the medium constituents with respect to CGTase production and activity. A 24 full factorial design (first order model) was carried out to identify the significant effect of medium components towards CGTase production. The variables involved in this initial screening study were sago starch, yeast extract, K2HPO 4 and MgSO4Â·7H2O. Statistical analysis of results have shown that only sago starch and yeast extract have a significant effect on CGTase production. A second-order model was proposed by using 2 2 central composite design to represent the production CGTase activity as a function of sago starch and yeast extract. The optimized values of 1.48% and 1.89% of sago starch and yeast extract was obtained, respectively. Under these proposed optimized conditions, the model predicted a CGTase activity of 79.66 U/ml and via experimental rechecking the model, an activity of 84 U/ml was attained.Mohd Khairizal MahatRosli Md. IlliasRoshanida A. RahmanNoor Aini Abd RashidNik Azmi Nik MahmoodOsman HassanSuraini Abdul AzizKamarulzaman Kamaruddin2008-11-17T08:20:44Z2018-09-19T05:07:06Zhttp://eprints.utm.my/id/eprint/id/eprint/6840This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/68402008-11-17T08:20:44ZInvestigation into low energy beta imaging using CCD imaging sensorAutoradiography is an extensively used technique to create a record of the radioactivity dispersion throughout the biological samples. Conventionally, this technique was performed using film. Spatial resolution and sensitivity are the main parameters of interest in developing new digital autoradiography systems. In conventional autoradiography, the images that have been documented display an excellent spatial resolution but at the same time show lack of sensitivity, very limited dynamic range and non-linear response. To overcome the disadvantages of this method, digital autoradiography systems have been developed to address the major drawbacks of the former technique.Suhairul Hashim2008-11-04T01:48:03Z2017-11-01T04:17:37Zhttp://eprints.utm.my/id/eprint/id/eprint/6733This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/67332008-11-04T01:48:03ZDetermination of noise equivalent quanta of medical screen-films
Noise equivalent quanta (NEQ) of Lanex Regular/T Mat G and Lanex Regular/T Mat L screen-film combinations were determined using modulation transfer function (MTF) and noise power spectrum (NPS) data. To accomplish this, average gamma of the radiograph was computed, the MTF and the NPS data were linearly interpolated and these values were used to compute the NEQ by means of a computer program. The computation shows that for spatial frequency 0â€“0.7 cycles/mm the NEQ of Lanex Regular/T Mat G is slightly lower than that of Lanex Regular/T Mat L, for spatial frequency 0.7â€“1.5 cycles/mm the NEQ of both are almost the same, and for frequencies greater than 1.5 cycles/mm the NEQ of the former is greater than that of the latter. Relatively, this indicates that low frequency signals show better on Lanex Rregula/T Mat L, but high frequency signals show better on Lanex Regular/T Mat G.Wan Muhamad Saridan Wan Hassansaridan@dfiz2.fs.utm.myYusof MunajatShamsul Sahibuddin2008-11-04T01:46:30Z2010-06-01T03:03:27Zhttp://eprints.utm.my/id/eprint/id/eprint/2520This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/25202008-11-04T01:46:30ZObjective and subjective image quality measures of medical screen-film systemsImage quality of Lanex Regular/T Mat G and Lanex Regular/T Mat L screen-film systems was measured objectively by means of noise equivalent quanta (NEQ) and subjectively by means of receiver operating characteristic (ROC) curve analysis to study the link between the two measures. For the objective measure, uniformly exposed radiographs and radiographs of bar pattern test object were used to determine the NEQ. For the subjective measure, detection of simulated lesions in posteroanterior anthropomorphic chest radiographs by an observer was analysed by the ROC methodology. Both measures show that a low frequency signal shows better on Lanex Regular/T Mat L, whilst a high frequency signal shows better on Lanex Regular/T Mat G.Wan Muhamad Saridan Wan Hassansaridan@dfiz2.fs.utm.myYusof MunajatShamsul Sahibuddin2008-06-19T01:27:19Z2018-03-07T21:01:48Zhttp://eprints.utm.my/id/eprint/id/eprint/5439This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/54392008-06-19T01:27:19ZThe use of adsorbents in the reduction of petrol volatile organic compound (VOC) emissionsThere has been growing concern over the impact of volatile organic compounds (VOCs) emissions since the implementation of self service petrol filling in Malaysia. High exposure to VOCs at petrol stations has been known to cause some hazardous effects on atmospheric environment and human health. The basis of this study was to determine the effectiveness of using activated carbon and peat in reducing the selected VOCs emission from the petrol sample. The five selected VOCs analyzed in this research were benzene, toluene, p-xylene, m-xylene and oxylene. Generally, the study showed that the selected VOCs emitted from the petrol sample were greatly reduced when adsorbents were used. However, the analysis results indicated that activated carbons were superior in total selected VOC reductions than peat, inferring that the total surface area of the adsorbent materials affected the selected VOC adsorption capacity. The effect of the vessel size on the adsorption capacity using a fixed amount of adsorbent was also investigated. The study showed that activated carbon contained in long vessel had resulted in an increase of adsorbent column height and hence adsorbed more of the target VOCs. The overall results of the analysis concluded that activated carbon mixed with glass chips showed the hlghest percentage of VOC reduction as it adsorbed more selected VOCs due to its higher contact surface area. The averages in the reduction of benzene, toluene and xylene isomers were 80.81 %, 93.18% and 94.04 - 98.56% respectivelyBee Min Goh2008-04-23T05:01:54Z2018-03-07T21:01:52Zhttp://eprints.utm.my/id/eprint/id/eprint/5442This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/54422008-04-23T05:01:54ZStudy on solutions of heat problems using finite difference methods and method of lines incorporate with RK-liked methodsThis dissertation reports a comparison of results from two classes of numerical methods for heat problems. The heat or diffusion equation, which is an example of parabolic equations are classified into the categories of the partial differential equations. Two classes of numerical methods, Method of Lines and Finite Difference Method are discussed. In Method of Lines, several Runge-Kutta methods were incorporated, including the third and fourth order. Finally, analysis on numerical results for the three heat problems is presented.Wan Rukaida Wan Abdullah2008-04-23T03:25:00Z2018-03-07T21:01:54Zhttp://eprints.utm.my/id/eprint/id/eprint/5443This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/54432008-04-23T03:25:00ZDesign and construction of magnetic flux leakage inspection system for ferromagnetic materialThe purpose of this study is to develop a magnetic flux leakage inspection system for ferromagnetic materials. It features a newly designed scanner, together with its signal processing circuit and software: Strong permanent magnet discs (1Tesla) are used to establish a magnetic flux in the material to be inspected. When there is no defect, the uniform flux remains in the plate. In contrast, flux leakage occurs outside the plate when there is a local defect due to corrosion or erosion. Hall effect sensor which can detect thls flux leakage is placed between the poles of the magnet and generate an electric signal proportional to the magnetic leakage flux. Defects causing a leakage flux exceedmg an adjustable predetermined threshold are detected and can be recorded. The amount of leakage flux is dependent on depth, width, breadth of the defects, and also the lie-off sensor and the plate thickness. The developed system enables fast scanning of ferromagnetic plate with qualitative results, with optimum speed 0.2-0.7ms-1. Its sensitivity is 0.2V(mT) -1 and it is able to resolve to defects as close as lrnrn apart. From the output signal displayed on the computer, the location and the severity of defects can be determinedToh Ming Wong2008-04-11T00:20:54Z2018-03-07T20:58:27Zhttp://eprints.utm.my/id/eprint/id/eprint/5346This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/53462008-04-11T00:20:54ZSintesis dan penggunaan cecair ionik terbitan N-Metilpirolidina dalam tindak balas diels-alderResearch in the use of ionic liquid as an alternative solvent for convensional organic solvents in organic synthesis is still in the early stage. In this research, Nmethylpyrrolidinium iodide salts have been synthesised from N-methylpyrrolidine with several alkyl iodides. The tetrafluoroborate and hexafluorophosphate salts were synthesised through metathesis reactions with silver tetrafluoroborate and silver hexafluorophosphate respectively. All salts obtained have been characterized using CHN elemental analysis, melting point, density, molar conductivity and 'H-NMR spectroscopy. The melting point range for the N-methylpyrrolidine salts is between room temperature and up to 300Â°C. The correlations between type of anions and alkyl chain length with melting point, density and molar conductivities have been studied. It was found that the length of the alkyl chain has no effect on the melting point of all the iodides, tetrafluoroborates and hexafluorophophates salts. However, the molar conductivities for the salts increase with increasing alkyl chains length and the type or the size of anion. The density of all the salts increase with increasing salts size. This is because salts with bigger size will have a higher density compared with those with smaller size. Room temperature ionic liquid N-methyl-N-propylpyrolidinium tetrafluoroborate (25) has been selected to be used as an alternative for organic solvents in three Diels-Alder reactions namely, cyclopentadiene (37) with maleic anhydride (41) and N-phenylmaleimide (38), and between N-phenylmaleimide (38) with 3-sulfolene (44). In these reactions, the adducts consist of a mixture of exo and endo stereoisomers The effect of heat towards yield percentage and stereoisomer ratio in the Diels-Alder reactions has been studied. Endo adduct was found to be the main stereoisomer if the reactions were carried out in the presence of heat. In contrast, the exo adduct was the main stereoisomer when the reaction is carried without heat treatment. However, the yield percentages and ratio of exo:endo adducts in ionic liquid solvent are higher than in convensional organic solvents either with or without the presence of heat. Preparative T.L.C, T.L.C, GC-MS, 'H-NMR spectroscopy, CHN and melting point methods have been used to characterize and confirm the adductSofian Ibrahim2008-03-27T09:26:39Z2018-03-07T20:57:49Zhttp://eprints.utm.my/id/eprint/id/eprint/5343This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/53432008-03-27T09:26:39ZPenyediaan kaca aerosilika daripada sekam padiThe aim of this study is to prepare aerosilica glass from silica aerogel synthesized from rice husk. The study was carried out in order to produce a low thermal conductivity aerosilica glass that can be used as thermal insulator. Aerosilica glasses of nominal composition 5 %-55 % mol of aerogel were prepared using a mixture of aerogel, SiOz with sodium carbonate, Na2C03. The glass samples of (Si02)@a20)1, were produced using liquid melt quenchng method at the melting temperature about 1 100 "C for aerosilica glass and 1400 "C for conventional sodium silicate glass. The study shows aerosilica glass is amorphous and exhibits better properties compared to conventional sodmn silicate glass with an optimum composition.of 20 % mol aerogel with density 2.39 g cm", thermal conductivity value of 1.35 ~ m k ' and Vickers micro hardness value of 412 Hv. According to the infrared spectrum, ths phenomena can be related to the structure of Si-0-Si bonds. The presence of foams by SEM micrograph contributes to the low thermal conductivity of aerosilica glass due to the formation of a new closed pores of 8 pm to 89 pm insize. The MAS-NMR spectra indicate a larger number of bridging 2 3 oxygen with Si atom in aerosilica glass as present Q ,Q and ~"pesies. The differential thermal analyzer shows aerosilica glass can be obtained at a lower temperature range of 8 18-828 "C which is stable against corrosive agents. W-VISNIR analysis shows the samples absorbance in UV light range is related to thermal conductivity.Rozieyati Abdullah2008-03-04T04:49:25Z2018-02-28T06:50:01Zhttp://eprints.utm.my/id/eprint/id/eprint/4918This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/49182008-03-04T04:49:25ZDevelopment of Argon fluoride (ArF) excimer laser ablation system and its diagnosis on optical materialsThe growing interest in precise fabrication of micro and nano-structures such as optical components, sensors and devices make the conventional approach no longer satisfactory for micro scale structure. Excimer laser ablation is particularly well suited for material such as polymer because of their excellent properties and ablation behavior. The objective of the project is to diagnose the ablation work for optical material. An ArF excimer laser was utilized as a source of energy. As a preliminary work, the laser was calibrated to determine the best performance of the laser beam. Various materials including thermal paper, high-density polyethylene (HDPE), plasticised polyvinyl chloride (PPVC) and polymethyl methacrylate (PMMA) material were employed as an ablating target. Each specimen was ablated with excimer laser which was operated at various parameter comprising of working distance, high voltage, repetition rate and number of pulses. The ablated materials were analysed by using Matrox Inspector 2.1, Video Test 5.0 and Ms Excel sofhvare. The changes in the refractive index of PMMA sample were analysed using Brewster angle. The results obtained showed that the ablation on these materials depended on working distance. A short working distance offered the best performance for ablation which was 30 cm, since less energy were lost during the propagation. The ablation work also depended on the high voltage in the range of 13 kV - 14kV, suitable for ablation process. The ablation work was also found to be independent with the repetition rate of the laser. Finally, the ablation was found sharply increased with respect to the number of pulses. The best performance for this study was found at 400 pulses. Two of the tested materials, PPVC and PMMA demonstrated good performance for the ablation work. The 3D image analysis, offer an estimation of depth of the ablation spot area. The refractive index of PMMA decreased from 1.46 to 1.23 in the range of 200 to 500 pulses.Mohd. Hazimin Mohd. Salleh2008-03-04T04:29:14Z2018-02-28T06:47:52Zhttp://eprints.utm.my/id/eprint/id/eprint/4813This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/48132008-03-04T04:29:14ZStudy and application of holography system for mechanical stress and surface deformationHolography is a technique to record information and reconstructs it in three dimensions. Although the technique was developed almost 40 years ago, it still possesses great potential and present rapid research in its application will continue. The aim of this project is to study various techniques of holography and the applications of holographic interferometry in mechanical stress and surface deformation measurement. Initially, a dark room and a vibration-free optical table are set-up. Low power He-Ne laser with output power of 1 mW and 10 mW are employed as light source. Various alignment techniques of holography setup are implemented and compared including Gabor holography, reflection holography, transmission holography, rainbow holography, data storage holography and double exposure holographic interferometry. In particular, the double exposure technique is applied to measure the Young's modulus of aluminum can and surface deformation of an object. Although the optical alignment is different for each technique, in general, they need to go through similar procedure: recording, developing, reconstruction and permanent record of hologram image. All the holograms are successfully developed and viewed in three dimensions. Double exposure hologram produces interference patterns which indicate the occurrence of deformation due to the stress given. The Young's modulus of the Aluminum can was measured to be (0.80 * 0.18) x 10' ~ m - ~ which is in the same order of magnitude with the mechanical measurement of (1.76 It 0.01) x 10' ~ m - ~ by the Universal Testing Machine by taking into account the calibration and measurement error. On the other hand, a surface deformation measurement system is developed and capable of detecting displacement up to 2.69 pm.Hock Chuan Kua2008-02-18T08:30:51Z2017-08-09T01:18:46Zhttp://eprints.utm.my/id/eprint/id/eprint/4571This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/45712008-02-18T08:30:51ZDevelopment of optimization Alghorithm for uncertain non-linear dynamical systemNonlinear optimal control problems are problems involving real world situations where the objectives are the maximization of the return from, or the minimization of the cost of, the operation of physical, social, and economic processes. Algorithms used to solve these problems are expected to satisfy the objectives consistently and since time translates into cost, must also be fast. An algorithm that definitely can satisfy the objectives is the Dynamic Integrated Systems Optimization and Parameter Estimation (DISOPE) algorithm. However, this algorithm has an inherent problem of slow convergence due to its gradient descent type updating mechanism. Hence, the purpose of this study is to overcome this convergence problem by modifying the mechanism. Two approaches were chosen for this purpose. The first is the use of momentum terms and the second is the parallel tangent method. Two new algorithms named DISOPE-MOMENTUM and DISOPE-PARTAN sprouted from these modifications and extensive simulations were performed to observe their performances. To strengthen the findings, theoretical analyses were done on each algorithm. These include optimality, stability, convergence, and the rate of convergence analyses. Based on the results of these simulations, we compared the number of iterations needed by each algorithm to arrive at the optimal solution and the CPU time taken for each algorithm to execute the search. From the theoretical analyses, comparisons were done on the speeds of contraction of the algorithms. Both new algorithms managed to arrive at the optimum in fewer numbers of iterations and in shorter CPU times than DISOPE without compromising on the accuracy of the solutions. The new algorithms also boast faster contractions. Both new algorithms performed better than DISOPE. This study succeeded in overcoming the problem of slow convergence and with the modifications, the new algorithms become more efficient in solving the optimal control problems.Mohd. Ismail Abdul Azizm_ismail@mel.fs.utm.myNazeeruddin Yaacobny@mel.fs.utm.myNorfarizan Mohd. SaidNor Hazadura Hamzah2007-06-29T02:43:33Z2007-06-29T02:43:33Zhttp://eprints.utm.my/id/eprint/id/eprint/3866This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/38662007-06-29T02:43:33ZBerkenaan persamaan kamiran rantau dan sempadan terhadap inti Bergman Inti Bergman telah diketahui menepati dua bentuk persamaan kamiran Fredholm jenis kedua; satu di atas sempadan dan satu di atas rantau. Kertas kerja ini akan menunjukkan hubungkait persamaan kamiran sempadan dengan persamaan kamiran rantau menerusi proses pengambilan had. Ali H.M. Muridahmm@mel.fs.utm.my2007-06-28T02:31:42Z2017-10-24T07:04:30Zhttp://eprints.utm.my/id/eprint/id/eprint/3855This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/38552007-06-28T02:31:42ZAn integral equation related to the Riemann problem for a simply connected region with cornersWe shall formulate a new integral equation related to the Riemann problem, a class of boundary value problems for analytic functions, on a simply connected region, bounded by a curve having a continuously turning tangent except possibly at a finite number of corners in the complex plane. The boundary data are assumed to be continuous. The solution to this problem may be characterized as a solution to a singular integral equation on the boundary. By using results of Hille and Muskhelishvili, the theory is extended to include boundaries with corners which are rarely used for numerical computations, mainly due to singularities and other difficulties, arising from the calculation of Cauchy-type contour integrals operating on singular functions around irregular shaped domains. The complex Dirichlet problem, which is a well-known classical boundary value problem, is a particular case of the Riemann problem. Swarztrauber derived an integral equation on the numerical solution for Dirichlet problem for a region of general shape. He used Picard iteration and obtained an iterative formula, then he wrote it in a form so that in numerical integrations the singularities were eliminated. Here, our propose is to present a direct method by extending Swarztrauber's results. In this paper, our new integral equation for Riemann problem with similar region is formulated based on these results. A numerical implementation of solving integral equation using the Picard iteration is suggested; presenting an iterative formula that will eliminate singularities during numerical integrations. I Muniraim@mel.fs.utm.myAli Hassan Mohamed Muridahmm@mel.fs.utm.myBahrom Sanugidfs@mel.fs.utm.my2007-06-27T08:45:09Z2017-10-24T07:02:53Zhttp://eprints.utm.my/id/eprint/id/eprint/3854This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/38542007-06-27T08:45:09ZAn integral equation for the external potential flow problemA second kind Fredholm integral equation is is presented in this paper for the two-dimensional, irrotational, incompressible fluid flow around obstacles with smooth boundaries. It is shown that the integral equation obtained is still valid if the obstacle is an airfoil without a cusp trailing edge. The integral equation is solved using the Nystrom. The numerical results obtained show a good agreement with the exact solutions. Ali Hassan Mohamed Muridahmm@mel.fs.utm.myMohamed M. S. Nassermms_nasser@mel.fs.utm.myNorsarahaida Saidina Aminnsarah@mel.fs.utm.my 2007-06-27T08:33:46Z2017-10-24T07:02:16Zhttp://eprints.utm.my/id/eprint/id/eprint/3852This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/38522007-06-27T08:33:46ZThe numerical solution of the non-uniquely solvable Riemann problem using a Fredholm integral equationThis paper is devoted to the computational aspect of the Riemann problem with non-unique solution in a simply connected region with smooth boundary. The boundary condition of the Riemann problem is transformed to a Fredholm integral equation of the second kind with continuous kernel. By imposing some side conditions, the integral equation can be solved using Nystrom method. The equivalence of the integral equation and the Riemann problem will be established for any smmoth Jordan curve. Typical examples illustrate that numerical results of high accuracy can be obtained provided that the boundaries are sufficiently smooth.Ali Hassan Mohamed Muridahmm@mel.fs.utm.myMohamed M. S. Nassermms_nasser@mel.fs.utm.myBahrom SanugiMohd. Nor Mohamadmohdnor@mel.fs.utm.my2007-05-22T07:08:25Z2017-08-01T01:06:37Zhttp://eprints.utm.my/id/eprint/id/eprint/2997This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/29972007-05-22T07:08:25ZDetection of multiple outliners in linear regression using nonparametric methodsThere have been considerable interest in recent years in the detection and accommodation of multiple outliers in linear regression. However, most of them are complicated and unappealing to users with no mathematical background. The clustering algorithm from Sebert et al. (1998) is discussed and used since it is easy to understand with interesting proposed approach and have a good performance in detecting the presence of outliers. Generally, method proposed by Sebert et al. (1998) is based on the use of single linkage clustering algorithm with the Euclidean distances to cluster the points in the plots of standard predicted versus residuals values from a linear regression model. The predicted and residual values are obtained from an ordinary least squares fit of the data. The algorithm is described and is shown to perform well on classic multiple outlier data sets. A modification is done to the Sebertâ€™s method by replacing the least squares (LS) with two robust estimators. Method 1 is a modification of Sebertâ€™s method where the list squares (LS) fit is replaced by the least median of squares (LMS) fit while Method 2 is a modification of Sebertâ€™s method where the least squares (LS) fit is replaced by the least trimmed of squares (LTS) fit. This reseach also provides a comparison between these three procedure to detect multiple outliers. A Monte Carlo simulations study was used to evaluate the effectiveness of these three procedures. All simulations and calculation were done using statistical package S-PLUS 2000. REFERENCES Agullo, J. (2000). New Algorithms for Computing the Least Trimmed Squares Regression Estimator. Computational Statistics and Data Analysis 36. 425-439. Aldenderfer M.S and Blashfield R.K.(1984). Cluster Analysis. USA: Sage Publications. Atkinson, A.C. (1986). Comment on â€˜Influential Observations, High Leverage Points, and Outliers in Linear regressionâ€™. Statistical Science I. 397-402.Robiah Adnanra@mel.fs.utm.my2007-05-21T07:01:26Z2012-05-02T04:59:39Zhttp://eprints.utm.my/id/eprint/id/eprint/2799This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/27992007-05-21T07:01:26ZKadomtsev-Petviashvili (Kp) nonlinear waves identification
By observing the periodic hexagonal pattern of surface waves in a large basin namely the MOB (Manoevering Ocean Basin) various solitons interactions patterns were observed due to the repetition of the interaction patterns of two Kadomtsev- Petviashvili (KP) solitons. This research is a systematic and comprehensive study on the Kadomtsev-Petviashvili (KP) equation. In particular the KP equation is the two dimensional form of the Korteweg-de Vries (KdV) equation. Soliton solutions of the KP equation using Hirota Bilinear method was adopted in this research. Two-soliton solutions of the KP equation can produce a triad, quadruplet and a non-resonance structures. In three-soliton solutions of the KP equation, many other interaction patterns can be observed. For example, a triad with a soliton and a quadruplet with a soliton. A computer program, KPPRO was developed using Microsoft Visual C++ to simulate various interactions patterns.
Chee Tiong OngWei King TiongMohd. Nor MohamadZainal Abd. AzizIsmail Kamis2007-05-18T07:15:38Z2012-05-22T03:25:14Zhttp://eprints.utm.my/id/eprint/id/eprint/2941This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/29412007-05-18T07:15:38ZParallel strategies on a distributed parallel computer system The formulation of a new parallel iteration methods are created to solve the parabolic equations in one, two and three dimensions run on a distributed parallel computer systems on the homogeneous parallel machines with 20 PC Intel Pentium IV, speed 1.6MHz and with PVM application platform. The development of IADE class and AGE with (4,2) and (2,2) accuracies are oriented by ADI algorithm with time level splitting strategy by an alternating way. The alternative iterative method for IADE and AGE classes is created. There are IADEI method which is based on Richardson's formula and AGE\_BRIAN which is based on linear interpolation concept. The development of a few strategies parallel is being as a mechanism for IADE to make it implemented in parallel. The Comparisons of the sequential performance measurements in IADE class with SUB, SOR, RB, MULTI, VECTOR and MF strategies are implicated the higher convergent and accuracy of IADEB-SUB and IADE-SUB methods. The Comparisons of the parallel performance measurements for IADE and AGE classes shown the elements of AGE class such as the overlapping subdomain and implicit block (2X2) are implicated the speedup and efficiency of AGE class is higher than IADE class. the minimum of the cost communication for the AGE class compared to IADEB-SUB and IADE-SUB are proved that AGE class is compatibility implemented on distributed parallel computer systems. The Expansion of AGE class on one, two and three dimensions for Cartesian, cylindrical and spherical coordinate systems make a decision that AGE-BRIAN methods is an alternative for AGE class in terms of convergent, accuracy, time executions, speedup, efficiency, effectiveness and temporal performance Communication activities and the consistent and work balance of data decomposition technique for CG method compatibility of the distributed parallel computer systems barriers.
Norma Alias2007-05-18T06:40:35Z2017-07-31T07:41:13Zhttp://eprints.utm.my/id/eprint/id/eprint/2990This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/29902007-05-18T06:40:35ZAnalyzing the relationships between organ failure and recuperating ability of patients in intensive care unitsA research on logit, probit and linear probability models have been carried out. The dependent variable being used is binary while the independent variables used consisted of eight variables which were binary, categorical and continuous. Research done based on these models covered its discoveries, functions of models, assumption of residuals, probability distributions and estimation techniques. A case study using the three methods of modeling as mentioned above was carried out. The influential variables were selected using forward stepwise method, backward stepwise method and manual selection. Selected variables using manual selection were based on the principle of parsimonious model. For each model, the results showed two out of eight chosen variables were significant at a significance level of 0.05. Tests on residual, multicollinearity, hypothesis testing, goodness of fit and influences and outliers data diagnostics were applied to these three models. Interpretations on estimated parameters were also carried out. After comparing the three models, it was found that logit model appeared to be the best model having the highest probability of accuracy. Softwares like ‘SPSS for Windows Version 10’, 'Minitab Release 13.2’ and ‘Microsoft Excel 2000’ were used to analyze these data.Zalina Mohd. Daudzalina@atma.gov.myIsmail MohamadMaizah Hura AhmadSaifullah Rusiman2007-05-18T02:19:08Z2017-05-14T07:46:14Zhttp://eprints.utm.my/id/eprint/id/eprint/2926This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/29262007-05-18T02:19:08ZInhibitory effects of compounds from Zingiberaceae species on platelet activating factor receptor bindingTen compounds isolated from Alpinia mutica Roxb., Curcuma xanthorrhiza Roxb. and Kaempferia rotunda Linn. (Family: Zingiberaceae) were investigated for their platelet-activating factor (PAF) antagonistic activities on rabbit platelets using 3H-PAF as a ligand. Among them, four compounds showed significant inhibitory effects. Alpinetin and 5,6-dehydrokawain isolated from A. mutica exhibited IC50 values of 41.6 and 59.3 Âµm, respectively. The IC50 values of 3-deacetylcrotepoxide and 2-hydroxy-4,4,6-trimethoxychalcone from K. rotunda were 45.6 and 57.4 ÂµM, respectively. 1-Methoxy-2-methyl-5-(1,5-dimethylhex-4-enyl)-benzene, synthesized by methylation of xanthorrhizol which was obtained from C. xanthorrhiza, showed an IC50 value of 40.9 Âµm. The results indicated that these compounds were relatively strong PAF receptor binding inhibitorsIbrahim JantanMazura PisarHasnah Mohd. SiratNorazah BasarShajarahtunnur JamilRasadah Mat AliJuriyati Jalil2007-05-18T06:39:27Z2011-12-21T07:46:27Zhttp://eprints.utm.my/id/eprint/id/eprint/2994This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/29942007-05-18T06:39:27ZA goal programming approach for the problems analyzed using the method of least squaresGoal programming (GP) is one of the most promising techniques for multiple objective decision analysis. Goal programming is a powerful tool which draws upon the highly developed and tested technique of linear programming, but provides a simultaneous solutions between variables, particularly for the purpose of understanding how one variable depend on one or more other variables. However, one of the main problems is that the method of least squares is biased by extreme cases. This study proposes goal programming as an alternative to analyze such problems. The analysis were done by using QM for Windows and MINITAB software package.Maizah Hura Ahmadmha@utm.my2007-03-21T04:39:01Z2010-06-01T03:00:18Zhttp://eprints.utm.my/id/eprint/id/eprint/2022This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/20222007-03-21T04:39:01ZIn-situ Ultrasonic Cleaning of Crossflow Sintered Tube Microfiltration: Effect of Sonication Cycle TimeA study was conducted to examine the effect of sonication cycle time on the in- situ ultrasonic cleaning of crossflow sintered tube microfiltration. The research involved attachment of vibra- bar transducer onto the membrane housing as a source of ultrasonic wave fields. Two sets of samples were used: yeast which represents the organic solids suspension, and titanium dioxide which represents the inorganic particles suspension. The research showed that the flux of the in-situ ultrasonic cleaning was increased by 58% for yeast suspension at sonication cycle time of 15 minutes, and an increment of 123% for titanium dioxide suspension at sonication cycle time of 10 minutes. The study concluded that application of in-situ ultrasound field in crossflow microfiltration processes managed to increase the filtration rate significantly, irrespective whether the particles are organic or inorganic in nature. The degree of flux improvement was dependent on the characteristics of the particulate suspension and the sonication cycle time. The main mechanism responsible in enhancing the filtration rate was the cavitational activities, caused by the ultrasonic irradiation, occurring near the filtering surface which reduces the overall resistance of permeate flow across the filter medium. Wan Rosmiza Zana Wan Dagangrosmiza@utm.myRosli Mohd YunusDayang Suhailawati Awang SulongAdnan Ripin2007-03-19T00:29:50Z2017-11-01T04:17:36Zhttp://eprints.utm.my/id/eprint/id/eprint/1939This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/19392007-03-19T00:29:50ZElectrophoretic migration of organophosphorus pesticides as a function of separation potential in micellar electrokinetic chromatography : a basis of predicting the retention factors
Retention Factors (K2) In Micellar Electrokinetic Chromatography (MEKC) Are Very Often Calculated Against The Mobility Of Fully Retained Hydrophobic Micelle Markers, Which Are Not Abundant For Universal Use. An Alternative Approach Was Proposed To Predict The K2 Values On The Basis Of A Functional Relationship Between The Solutes Retention Times And Separation Potentials Using Organophosphorus Pesticides (Opps) As Reference Hydrophobic Compounds. The Use Of The Proposed Simple Linear Model Was Evaluated For Another Set Of Hydrophilic Opps And Its Practicality Was Defined.W. Aini W. IbrahimS. M. Monjurul AlamA. B. Sulaiman2007-01-30T01:24:08Z2017-05-14T06:52:28Zhttp://eprints.utm.my/id/eprint/id/eprint/28This item is in the repository with the URL: http://eprints.utm.my/id/eprint/id/eprint/282007-01-30T01:24:08ZLeast criminals for some given conjectures in group theoryIn the theory of finite groups, many major theorems have been proved by the minimum counterexample technique or sometimes called â€œleast criminalsâ€? technique. It uses the fact that if there is a counterexample to a given theorem, then there is a counterexample of smallest possible order. In this paper, we will find the least criminals for five given conjectures in group theory
Nor Haniza SarminSheila Ilangovan