Theses & Dissertations

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https://hdl.handle.net/20.500.14170/2002

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  • Publication
    Numerical simulation of stress shielding induced by crack interaction in human phalanx bone
    ( 2014)
    Siti Aisyah Abdul Halim
    Bone fracture is an injury not uncommon to everyday life. Most of the time, it leaves permanent damage and a long period of recovery. This situation can be prevented if we understand the mechanics and the process of the bone fracture. This study aims is to evaluate stress shielding induced by crack interaction using a simple model based on Linear Elastic Fracture Mechanics (LEFM). This simulation based on the determination of the Stress Intensity Factor (SIF) and the changes of stress shielding in different crack interval towards the human phalanx bone. Numerical simulation had been carried out in this project to understand the stress shielding induced by crack interaction. The results revealed that the interaction of two cracks is directly proportional to the SIF magnitude and interaction factor at the crack tips. The parallel cracks have experienced increasing shielding effect as the cracks interval increase. The crack interaction limit (CIL) and crack unification limit (CUL) also had been accomplished for every range of crack interval in this project. Several improvements will be conducted for future development of this study, including various stresses loading subjected to the model, porous element added in the model, different planes of the model and use various methods in calculating the stress intensity factor (SIF).
      4  7
  • Publication
    Magnetohydrodynamic (MHD) stagnation point flow and heat transfer towards a stretching sheet with suction in a Nanofluid
    ( 2014)
    Nurul Najwa Mansor
    The magnetohydrodynamic (MHD) stagnation point flow and heat transfer towards a stretching sheet in a nanofluid with suction is investigated. The basic equations governing the fluid flow and heat transfer are transformed into nonlinear ordinary differential equation using a similarity transformation, before being solved by means of a shooting method. The effects of suction parameter on the skin friction coefficient, the local Nusselt number and the local Sherwood number as well as the velocity and the temperature profiles are obtained and analyzed. The numerical results indicate that the magnitude skin friction coefficient, the local Nusselt number and the local Sherwood number increase with suction effect.
      2  6
  • Publication
    A study of LIE group method and its application to solve the unsteady transonic flow
    ( 2014)
    Mohammad Huskhazrin Kharuddin
    The non-linear equations of motion describing the unsteady transonic flow in cartesian coordinates are considered in this dissertation. A method known as Lie group which reduce the non-linear partial differential equation to an ordinary differential equation on the basis of the underlying symmetry structure has been used. The Lie method is quite useful in reducing a complex equation to an easy-to-handle ordinary differential equation. By employing the Lie theory, the full one-parameter infinitesimal transformation group leaving the equations of motion invariance is derived along with its associated Lie algebra. Subgroups of the full group are then used to obtain a reduction by one in the number of independent variables in the system. These reductions are continued until an ordinary differential equation is reached. A series type exact solution of these reduced ordinary differential equation is obtained which leads to a series type exact solution of the unsteady transonic flow equation. The Lie group method seems to be an appropriate choice to handle these nonlinear equation.
      1  5
  • Publication
    Monitoring product quality in cliching process: comparison between univariate and multivariate control charts
    ( 2014)
    Ibrahim Sulong
    In this dissertation, we investigate the stability of clinching process for assembly of LED Lamps II. Currently, univariate control charts such as X chart and R chart are develop for monitoring process target and process variability. However, the company management under study is highlighting the issue of quality in a clinching process because univariate control charts allow only monitoring one quality characteritic at a time. In multivariate environment, there are more than one quality characteristics to be monitored and those characteristics are correlated.
      7  9
  • Publication
    Numerical simulation of stress amplification induced by crack interaction in human femur bone
    ( 2014)
    Noor Alia Md Zain
    This research is about numerical simulation using computational method which study on stress amplification induced by crack interaction in human femur bone. Crack in human femur bone usually occur because of large load or stress applied on it. Usually, the fracture takes longer time to heal itself. The crack interaction is still not well understood due to bone complexity. Thus, brittle fracture behaviour of bone may be underestimated and inaccurate. This study aims in investigating the geometrical effect of double co-planar edge cracks on stress intensity factor (K) in femur bone. Other than that, this research also focus in the amplification effect on fracture behaviour of double co-planar edge cracks, where numerical model is developed using computational method. The concept of fracture mechanics and numerical approaches to solve interacting cracks problems using linear elastic fracture mechanics (LEFM) theory is used. So, it is important to study what is the parameter that can minimize the crack propagation to prevent complete failure. This study has shown that the crack interaction limit (CIL) and crack unification limit (CUL) exist in the model developed. In future development of this research, several improvements will be made such as varying the load, applying thickness on the model and also use different theory or method in calculating the stress intensity factor (K).
      1  8
  • Publication
    Heuristic method for the modified model of capacitated arc routing problems
    ( 2015)
    Muhamad Hafiz Masran
    The management of waste collection in urban areas is a critical issue for some developing countries especially in Malaysia which requires immediate attention. This study attempts to make an analysis and assessment of the development of the Perlis state waste generation distribution and the optimization of waste collection routes. This thesis describes the architecture design of the mathematical modeling for the mixed graph of Capacitated Arc Routing Problem (MCARP) extended from the Capacitated Arc Routing Problem (CARP). Furthermore, it provides a description of several equations that can be used to obtain efficient collection routes such as capacity vehicles constraint. To get the better result, this study used the existing heuristics method for solving MCARP mathematical modeling. The result shows that the total costs produced are considerably acceptable and are also reasonably improved, although the existing heuristics method do not obtain an optimal solution but in term of the computational time is good and better than other methods for small and intermediate networks especially in the mixed graph problem
      6  15
  • Publication
    Application of program evaluation and review technique (PERT) and linear programming (LP) in project management
    ( 2015)
    Siti Fairuz A. Rahim
    Throughout the years, businesses execute a systematic change, such as constructing a building, merging with another company or making a new product. These changes lead to the management of a project. To construct a project, various dataflow are required. However, project management nowadays demand more complex products, higher quality outputs and faster development cycles. This will cause massive scale of planning a project which leads to massive cost. Therefore, this study aims for an optimization in managing a project. The Program Evaluation and Review Technique (PERT) which originally designed to plan a project that emphasizes the relationship between the times each activity takes and the resulting time and cost for the expected completion of the entire project. In PERT, a graphical network is used to illustrate the precedence or parallel relationship among the activities. It‟s also identifying the expected completion time of a project and the critical path where more resources should be concentrated to finish the project on time. However, the expected time of a project can also be shorten to a certain level by the used of additional resources which is called crashing. Reducing the duration might include using overtime, assigning more labour and using more resources such as material, equipment and so on. These actions may result in higher cost and lower quality. Thus, crashing decision can be formulated by using Linear Programming (LP). LP technique seeks to determine the optimization project cost. It is also boast efficiency of computational algorithm for problems with thousands of constraint and variables which analyse by using Excel Solver. In this research, PERT and LP are applied on a large-scale of projects which construct a new building consist of Administration Office and Medan Selera at the Main Campus of University Malaysia Perlis (UniMAP), Mukim Padang Siding, Pauh, Perlis
      1  5
  • Publication
    Modelling and simulation of clustering vehicle routing problem in distribution of burger products
    (Universiti Malaysia Perlis (UniMAP), 2015)
    Rosniza Mohd Nor
    The vehicle routing problem (VRP) in this dissertation aims to minimize the travelling time that satisfies the customers' demands under vehicle capacity by implementing clustering locations. The areas of study focused on 38 customer locations of the case company. Modelling and simulation using the package of Pro Model software where it assists in the objective of implementation. There are two models designed separately due to the limitations of the student version. Neither model did not affected the result in the VRP route plan. Data from the model of VRP distribution results will be compared with data from the case study for system improvement. There is 81.25% of reduction in customer locations to 10 clustering locations, which can reduce the use of vehicle travel time. With the implementation of clustering locations, there are 50.40% (Route 1 and Route 2) and 16.70% (Route 3) of travel time in the system that can be improved. The simulation model can help a company owner to predict the effectiveness of delivering products in terms of travel time when implementing the clustering locations without disturbing the real system.
      33  17
  • Publication
    Application of Program Evaluation and Review Technique (PERT) and Linear Programming (LP) in project management
    ( 2015)
    Siti Fairuz A. Rahim
    Throughout the years, businesses execute a systematic change, such as constructing a building, merging with another company or making a new product. These changes lead to the management of a project. To construct a project, various dataflow are required. However, project management nowadays demand more complex products, higher quality outputs and faster development cycles. This will cause massive scale of planning a project which leads to massive cost. Therefore, this study aims for an optimization in managing a project. The Program Evaluation and Review Technique (PERT) which originally designed to plan a project that emphasizes the relationship between the times each activity takes and the resulting time and cost for the expected completion of the entire project. In PERT, a graphical network is used to illustrate the precedence or parallel relationship among the activities. It‟s also identifying the expected completion time of a project and the critical path where more resources should be concentrated to finish the project on time. However, the expected time of a project can also be shorten to a certain level by the used of additional resources which is called crashing. Reducing the duration might include using overtime, assigning more labour and using more resources such as material, equipment and so on. These actions may result in higher cost and lower quality. Thus, crashing decision can be formulated by using Linear Programming (LP). LP technique seeks to determine the optimization project cost. It is also boast efficiency of computational algorithm for problems with thousands of constraint and variables which analyse by using Excel Solver. In this research, PERT and LP are applied on a large-scale of projects which construct a new building consist of Administration Office and Medan Selera at the Main Campus of University Malaysia Perlis (UniMAP), Mukim Padang Siding, Pauh, Perlis
      7  15
  • Publication
    Factors contributing to air pollution levels using factor analysis
    ( 2015)
    Asmarini Mohamed
    The aims of this study is to determine the major factors and causes of air pollution levels within the four selected Malaysian air monitoring stations. The data were obtained from January 2008 to December 2012. The variables concerned are two meteorological factors (temperature and relative humidity) and four air pollutants (CO, PM10, O3 and NO2). The focus areas comprise of four different localities which are; Perai (S1- industrial), Shah Alam (S2-urban), Seberang Jaya (S3-suburban) and Jerantut (S4- control). Two statistical methods were selected to analyze the datasets which are descriptive statistical analysis and factor analysis. The descriptive statistical analysis showed that Perai recorded the highest concentrations of CO, O3 and NO2 while Seberang Jaya recorded the highest concentration of PM10. The results of the factor analysis showed that there were three factors at Perai, Shah Alam and Jerantut while two factors at Seberang Jaya. However, the combination of the components in each factors are different for every station. Nevertheless, it has a significant combination of the components at Perai where it can be categorized as an Organic Pollution Factor, Meteorological Factor and Fuel Factor. These results present a guideline to establish evaluations appropriate to pollution characteristics and classification systems for air quality monitoring stations in Malaysia.
      10  6
  • Publication
    Differential transformation method (DTM) for solving SIS and SI epidemic models
    (Universiti Malaysia Perlis (UniMAP), 2015)
    Doha Suliman Abedalqader Alsarayreh
    Differential equations play an important role in modeling real world problem. One of the importance of differential equations is seen in the SIS and SIR epidemic models. Many researches have been proposed to solve SIS and SIR models numerically. However, there is no study about the application of Differential Transformation Method (DTM) for solving SIS and SI epidemic models. In this study, DTM is proposed to solve the SIS and SI epidemic models for constant population. Firstly, the theoretical background of DTM is studied and followed by constructing the solutions of SIS and SI epidemic models. Furthermore, the convergence analysis of DTM is proven by proposing two theorems. Finally, numerical computations are made and compare with the exact solution. From the numerical result, the solution produced by DTM approaches the exact solution which agreed with the proposed theorems. In summary, DTM is an alternative technique to be considered in solving many practical problems involving differential equations.
  • Publication
    Modelling and simulation of mixed quieuing server pharmacy system with adjustable parameters
    ( 2015)
    Rashida Abd Rashid
    This dissertation involves discrete event simulation (DES) as a type of computer based modelling that imitates a real world system of pharmacy unit. Queuing theory that is used to model and analyse the characteristic of queuing system at the pharmacy unit of Hospital Tuanku Fauziah, Kangar. The input of this model is based on statistical data collected for 20 working days in June 2014. Currently patient waiting time of pharmacy unit is more than 15 minutes. The actual operation of the pharmacy unit is a mixed queuing server with M / M / 2 queuing model where the adjustable parameter is refer to the pharmacist. Discrete event simulation method and ProModel software is used to simulate the queuing model and to propose the improvement for queuing system at pharmacy unit. Waiting time for each counter is analysed and found out that Counter 3 and 4 has the highest waiting time which is 16.98 and 16.73 minutes. Three scenarios; M / M / 3 , M / M / 4 and M / M / 5 are simulated by using ‘What If Analysis’ and waiting time for actual queuing model and experimental queuing model are compared. The simulation results show that by adding the server (pharmacist) will reduce patient waiting time. Almost 50% average patient waiting time is reduced when one pharmacist is added to the counter. However, it is not necessary to fully utilize all counters because eventhough M / M / 4 and M / M / 5 produced more reduction in patient waiting time, but it is ineffective since Counter 5 is rarely used and current average patient waiting time for Counter 6 is 1.99 minutes
      2  6
  • Publication
    The modelling and simulation on burger production process: a case study in small and medium industry
    (Universiti Malaysia Perlis (UniMAP), 2015)
    Syarafun Nisa Zahelem
    This simulation study focuses on burger production process runs by a SMI (small and medium industry) located in Kedah. The aim of this study is to develop the current production line of the company in order to observe the performance of the system and then suggest the methods for improvement. The efficiency of the current system including the utilization of workstations and workers are estimated from the simulation result. The outputs of simulation are compared with the actual data for validity of the simulation model. This study enables the observation of Queuing Theory application in discrete-event simulation. Queuing Theory is used to develop the mathematical model of the production line. Based on the results from current simulation model, bottleneck of the system is identified. As the company plans to increase the production, therefore an improvement model is built to forecast the possible outcome of the increasing production capacity. The proposed actions are adding another machine at bottleneck point and adding more workers for speeding up the manual tasks. By adding the machine, the structure of multiple server queuing model is observed. The results from the improvement model shows 92%achievement from the targeted output whenever the machine is added. By increasing the number of workers, the total of finish product also increases with 98% from the target. Therefore, it can be concluded that the company is able to increase the production capacity by doing few adjustment on the current burger production system. From the study, methods to improve the production line and increase the production rate are identified where they need to add another forming machine and more workers to speed up the tasks.
      2  1
  • Publication
    Extended hamming distance method for measuring the perfomance of academic staff
    ( 2015)
    Rasyida Md Saad
    This research presents an extended Hamming distance method in measuring the performance of the academic staff. Generally, performance appraisal is responsible in determining the employee works, in which involving in making personnel decisions and employee development. As this process can be used to identify the performance of the employee, a proper method has to be applied in selecting the best employee performance. Multi criteria decision making (MCDM) method is one of the solution for this problem. In this research one of the existing MCDM methods which is a Hamming distance method is extended. Inspired by the Canós algorithm, the extension of the existing algorithm is done. The use of subjective weight and fuzzy linguistic variables are introduced in the newly extended method. The use of criteria weight is essential in evaluating the performance of the alternative. In addition, Shannon’s entropy concept is also applied to determine the most important criteria. Meanwhile, the use of fuzzy linguistic variables will help in dealing with subjective assessment. The extended Hamming distance method is presented in a well-built framework which also depicted in this research. A study case in one of the institute in Universiti Malaysia Perlis, which is Institute of Engineering Mathematics in determining the best academic staff for three years, which are 2010, 2011 and 2012 is presented to validate the extended method. By utilizing the extended method, the most important criteria, the ranking of the academic staff and problems regarding the ranking process for three years are identified. The comparison between the final results of the extended method and TOPSIS method is also done. Based on the final results obtained, it can be concluded that the results for the criteria weight and ranking of the academic staff for the years 2010 and 2011 are different than the year 2012. For the years 2010 and 2011, A22 is declared as the best academic staff. Meanwhile, for the year 2012, the best academic staff is belong to A3. C11 is declared as the most important criteria for the years 2010 and 2011. However, for the year 2012, C6 is declared as the most important criteria. The similarity in the final results between the extended method and TOPSIS method is also identified. Through the application of the extended method it is hope to ease the difficulty in decision making process especially in determining the best performance of the academic staff.
      4  18
  • Publication
    Variational Monte Carlo study of light nuclei
    ( 2015)
    Khairul Anwar Mohamad Khazali
    An outstanding problem in Variational Monte Carlo (VMC) calculations with realistic interactions like Argonne V18 and Urbana IX three-body interactions is that p-shell nuclei turn out to be grossly under bound as compared to the Green’s Function Monte Carlo (GFMC) calculations. A similar situation exists in Diffusion Monte Carlo calculations with somewhat simplified interactions. In this thesis, we improve upon the VMC calculations by bringing about several variations in the established procedure of performing variational calculations. In the first variation, the effect of the errors as a function of the number of particles in the variational wave function are analyzed and then a correction through expanding the radial part in terms of a complete set are made and treat the expansion coefficients as variational parameters. Second variation consists in modifying the variational wave function structure. The state of the art variational wave function for s- and p-shell nuclei consists of two parts, where the first part is a Jastrow part operated upon by a symmetrized sum of two-body operatorial correlations and in the second part this outcome is then operated by a sum of unity, operatorial threebody and spin-orbit two-body correlations. A considerable improvement is obtained over the binding energies, wave functions and variance for the light nuclei 3H, 4He and 6Li by using these two variations. We obtain noticeable improvement in the quality of the wave function and lowering of the energies compared to earlier results. The new energies are –8.38 MeV, –28.07 MeV and –29.90 MeV for 3H, 4He, and 6Li respectively. All the computations have been taken away on a multiprocessor machine developed indigenously
      4  13
  • Publication
    A rational cubic spline technique for preserving the positivity of data
    ( 2016)
    Anas Khalaf Faris Al-Abbasi
    This work intends to address the problem of the visualization of curves (2-dimensional data representation) and surfaces (3-dimensional data representation) with the aim and provision that their display looks smooth and modifiable. In order to achieve these goals, we proposed a C1 spline interpolation. For the treatment of the 2D data visualization problem, the proposed function has been made to contain three positive shape parameters in each subinterval of its construction. Simple data-dependent constraints are derived for single shape parameter to ensure preserving the positivity through given positive data while the remaining two parameters are left free for designer’s choice for the curves’ refinement and/or manipulation. This interpolation has been extended into rational bi-cubic spline interpolation to treat the problem of 3D data visualization. The extended interpolation has been made to involve six positive shape parameters in each rectangular patch of the surface construction. In this case, constraints are derived for two shape parameters for conserving the surface positivity while the remaining four parameters are left free according to designer’s will for the surface smoothing and/or manipulating. Half of these shape parameters are set in the x-direction and the other half are set in the y-direction in such a way that each one of the free parameters can be changed separately to obtain different data representation models accordingly. The scheme under discussion is locally effective on the data intervals and does not allow to be inserted with any new knots to preserve the positivity. Numerical examples are provided to demonstrate that the proposed scheme is successfully producing interactive, smooth and modifiable curves and surfaces.
      7  12
  • Publication
    An extended thomas-fermi model with clustering in Nuclei
    ( 2016)
    Nooraihan Abdullah
    In this study, a phenomenological theory of nuclei that includes clustering at the nuclear surface in a general form is presented. The theory elaborates the recently extracted large symmetry energy by Natowitz et al., at low densities of nuclear matter and is fully consistent with the static properties of nuclei. Clusters of all sizes and shapes together with medium alterations are included in a phenomenological way. Discussion about the symmetric nuclear matter properties are presented in detail. Arguments are stated, which bring to an equation of state of nuclear matter consistent with clustering in the low-density region. In addition, the justification and discussion about the properties of asymmetric nuclear matter are given. Due to the clustering, an interesting interpretation of the equation of state of asymmetric nuclear matter comes into view. An extended version of Thomas-Fermi theory is adopted as a framework for nuclei where it also consist of the phenomenological pairing and Wigner contributions. This theory relates the nuclear matter equation of state, which includes clustering at low densities, with clustering in nuclei at the nuclear surface. Calculations are carried out for different equations of state of nuclear matter. This study take into account binding energies of 2149 nuclei for N,Z  8. The significance of the quartic term in symmetry energy is illustrated at and below the saturation density of nuclear matter. It is demonstrated that it is greatly connected to the use of ab initio, a realistic equation of state of neutron matter, especially the contribution originating from the three neutron interactions and rather clustering. The causes for these are presented. The neutron skin thickness in nuclei is found to reduce significantly, for the reason of clustering. The developed theory predicts circumstances and methodologies to be examine both theoretically and experimentally.
      1  8
  • Publication
    One dimensional heat transfer through rectangular fin using finite element method (FEM)
    (Universiti Malaysia Perlis (UniMAP), 2016)
    Maryam 'Azyyati Ab Aziz
    This dissertation present a study of heat transfer through rectangular fin by using finite element method. In solving heat related problem, there are many methods that can be used. This study will be focused on this area with the objectives to develop FEM algorithm using MATLAB for 1-D heat transfer problem. By applying this algorithm to solve 1-D heat transfer problem, we will compare both numerical and exact solution result. From here, the variables of different number of nodes, length and conductivity properties were tested to investigate the effect. By focusing on 1-Dimenesional heat equation, the Galerkin method is used. This study will apply numerical solution technique using FEM to solve !-dimensional heat transfer through rectangular fins and developed a suitable algorithm for computational purpose. As expected, the results obtain are coherent with the theory with a negligible difference. Overall, this research shows that the number of nodes can affect the accuracy of result however the difference is so small that it does not have much effect. Meanwhile, the length does not relate or affect the number of nodes and are independent variable. Lastly, the material properties are the only variable that can affect both number of nodes and length.
  • Publication
    Numerical simulation of the burger's equation
    ( 2016)
    Intan Mastura Ramlee
    In this study, the exponential finite difference technique has been used to solve one-dimensional Burgers’ equation with different value of h (step size). Burgers’ equation is considered in this study because the equation governing simple nonlinear diffusion process. Since Burgers’ equation is nonlinear equation, the Hopf-Cole transformation has been applied to convert the equation to one-dimensional heat equation. Consequently, the exponential finite difference method has been used to generate of one-dimensional heat equation. Three techniques called explicit exponential finite difference method, implicit exponential finite difference method and modified Burgers’ equation using explicit exponential finite difference method have been implemented. In the solution process, the explicit exponential finite difference method used a direct to solve the Burgers’ equation while the implicit exponential finite difference method leads to a system of nonlinear equation. At each time-level, Newton’s method is used to solve the nonlinear system. The solution of the onedimensional modified Burgers’ equation by using the explicit exponential finite difference method. The solution process have been discretized the time derivative and spatial derivative using exponential finite difference technique. Numerical solutions for each method are compared with exact solution and the results obtained using three methods are precise and reliable. The percent errors are compute and found to be sufficiently small.
      1  9
  • Publication
    Approximating one-dimensional coupled shallow water equation for predicting Tsunami wave propagation using new semi-implicit method
    ( 2016)
    Siti Maryam Hafiza Mohd Kanafiah
    Tsunamis are uncommon events compared to natural hazards. Population growth along the shorelines has increased the statistic of the number of victims affected by the tsunami disaster. In order to help people to be aware about the tsunami disasters, a tsunami wave propagation must be predicted. This study proposed a one dimensional coupled shallow water equation for predicting the tsunami wave propagation. The simulation of numerical modelling was conducted to predict the occurrence of tsunami wave propagation. In order to approximate the shallow water equation, the discretization process was conducted using a new semi-implicit method which is one of the methods in finite difference method. A problem regarding the free surface wave damping problem were used in validating the semiimplicit method. After the validation process, the numerical algorithm was developed in MATLAB software to solve the one dimensional coupled shallow water equation for the tsunami wave propagation. For the purposes of the simulation, the boundary condition and initial condition, the spatial steps and time steps as well as the approximation of shallow water equation were encoded. The simulation results of one dimensional shallow water equation successfully predicted the behaviour of the tsunami propagation near the coastline after the earthquake ground shaking occurred.
      1  5