Faculty of Engineering and Built Environment
Universiti Kebangsaan Malaysia

Volume 21 (2009)

Table of Contents

No. Article Detail
1. Ciri-ciri Asas Beberapa Tanah Yang Dikisar (Fundamental Properties of Few Crushed Soil)
Mohd Raihan Taha, Lim Sook Yee & Zamri ChikAbstract
Laboratory experiments were conducted to study the fundamental properties of kaolinite, montmorillonite and a UKM soil at nano levels. SEM analysis showed that much more nano size particles were obtained after the milling process. Testings and comparison of the properties of kaolinite, montmorillonite and UKM soil with regard to its liquid limit, plastic limit, plasticity index, specific surface, pH and specific gravity at the normal and after crushing were then conducted. Laboratory tests results showed that the values of liquid limit, plastic limit, specific surface and specific gravity of soil/clay were higher after crushing, but its pH and plasticity index were lower compared to the initial soil samples. The results of soil strength test showed that when the percentage of crushed particles in the soil/clay is increased, the strength of the soil/clay will also be increased. Thus, crushed soil/clay or nanoparticles are potentially suitable for changing and improving the properties of soil/clay for various applications.
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2. Address Resolution Protocol Optimization
J.L. Tai, Nor Adnan Yahaya & K. Daniel WongAbstract
This paper proposes an improved Address Resolution Protocol (ARP) for Ethernet-based networks. In the proposed alternative method, the ARP request packets are not broadcasted but instead unicasted to an ARP server which will have all the <ip, MAC> mappings of all the hosts connected to the network. This significantly reduces ARP signaling and processing overhead. The ARP server obtains the mappings through a novel passive method that does not introduce additional overhead in the network. Furthermore, the use of the ARP server makes it much easier to secure the network against certain attacks like ARP poisoning.
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Analisis Data Rawak Terikan-Lesu Menggunakan Kaedah Statistik Purata-Tergerak (Analysis of Fatigue Road Loading Using The Average Statistical Method)
Shahrum Abdullah, Mohammad Darahim Ibrahim, Azami Zaharim & Zulkifli Mohd NopiahAbstract

This paper presents the analysis of fatigue road loading which was measured on a component of an automobile suspension system. Thus, this significant technique was introduced for preserving data associated to the underlying probabilistic properties that are related to the fatigue damage. The analysis was based on the fatigue damage potential, which was related to the random variables in a time series data. Using this data type, the analysis was performed by means of the statistical method, such as the Moving Average technique. This model can then be applied to estimate the data trend by using the related Moving Average models in order to reduce a random variation of fatigue data. In this study, the data were experimentally measured on an automobile suspension system which was travelling over a public road surface. During the measurement, the data collection was performed at the sampling rate of 200 Hz in the 300 second of the record length. For the analysis, the Moving Average method was applied to the fatigue data in order to determine the parameters related to Mean Absolute Percentage Error (MAPE), Mean Absolute Deviation (MAD) and Mean Squared Deviation (MSD). In addition, the significant analysis of data correlation based on Autocorrelation Function (ACF) and Partial Autocorrelation Function (PACF) was also discussed. Finally, it is suggested that this method provided a good platform to process the changeable random fatigue strain loading in order to produce a stationary data, with the removal of the nonstationary parts.

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4. Kajian Ciri-ciri Pasir Pengalas dan Pengisi Sambungan Turapan Blok Konkrit Saling Mengunci (Study of Sand Characteristics as Bearing and Filler in Joint of Inter-locking Concrete Block Pavement)
Nur Izzi Md. Yusoff, Amiruddin Ismail, Rosli Hainin, Hasanan Md. Nor & Khairul Anwar HusinAbstract
The use of interlocking concrete block pavement as a road surface has increased in the road construction recently. This study was conducted to envisage the problems occur particularly for the bedding and joint filling sand of the interlocking concrete block pavement. Moreover, the effect of the moisture on the bedding sand was also studied. Two type of additives namely as palm oil fly ash (POFA) and silica fume, which carry the pozzolanic behaviour, were mixed with joint filling sand in order to improve its quality. These materials are industrial waste compound which can be easily found in Malaysia. Two types of permeability experiments, the constant and falling head tests were conducted to evaluate the permeability of the joint filling sands with the percentage additives used of 2%, 4%, 6%, 8% and 10%. A physical model was developed to investigate the degree of compaction and water absorption via sand in joints. Water absorption test was also conducted onto the model with the addition of additives of 0%, 5% and 10% with the joint filling sand for 5 and 10 days. Study shown that the incorporation of additives reduced the permeability of joint filling sand with the optimum values obtained for both POFA and silica fume mixtures both were at 2% respectively.
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5. L-Momen Peringkat Tinggi: Penggunaan Bagi Memodelkan Taburan Logistik Teritlak (LH Moment: The Usage To Model General Logistic Distribution)
Ani Shabri & Abdul Aziz JemainAbstract
Estimation of floods of large return periods is often required in engineering structure design. This study introduces a method based on LH-moments (LMT) to use generalized logistic (GL) distribution for estimating the upper-part of distribution. Application of the GL distribution using both LMOM and LMT parameter estimates from two actual data are demonstrated. The performance of the LMT method and the LMOM method are assessed by evaluating the bias and mean square error (MSE) of quantile estimates through Monte Carlo simulations with the presence of outlier. Monte Carlo simulation results show that LMT lead to reduced biasand mean square error (MSE) for F = 0.90 and poorer estimation for F = 0.999 compared to L-moments. For the estimation of x(F = 0.9), LMT are in many cases significantly more efficient than LMOM only for sample sizes, n<20.
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6. Load Forecasting Using Time Series Models
Fadhilah Abd. Razak, Mahendran Shitan, Amir H. Hashim & Izham Z. AbidinAbstract
Load forecasting is a process of predicting the future load demands. It is important for power system planners and demand controllers in ensuring that there would be enough generation to cope with the increasing demand. Accurate model for load forecasting can lead to a better budget planning, maintenance scheduling and fuel management. This paper presents an attempt to forecast the maximum demand of electricity by finding an appropriate time series model. The methods considered in this study include the Naïve method, Exponential smoothing, Seasonal Holt-Winters, ARMA, ARAR algorithm, and Regression with ARMA Errors. The performance of these different methods was evaluated by using the forecasting accuracy criteria namely, the Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Mean Absolute Relative Percentage Error (MARPE). Based on these three criteria the pure auto regressive model with an order 2, or AR (2) under ARMA family emerged as the best model for forecasting electricity demand.
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7. Penentuan Tahap Kakisan Tetulang Keluli Menggunakan Kaedah Pengecilan Amplitud (Determination of Rebar Corrosion Rate Using Amplitude Attenuation Method)
Roszilah Hamid, Khairul Anuar Mohd Nayan, Kamarudin Mohd Yusof & Wan Marzuliani Wan Mohd Abstract
This study is to determine whether the amplitude attenuation method can be used to measure the corrosion rate of rebars without having to hack the sructure nor it need not to be in saturated form. A pressure wave is generated by dropping a small steel ball onto the concrete surface. This wave will propagate through the concrete and will be reflected by defects and the opposite surface of the concrete. The wave in the form of amplitude verses frequency is recorded. The frequency reflected by the rebar, fst, can be determined based on CP, the wave velocity in concrete, and the thickness of the concrete cover. Concrete prisms (300 × 150 × 150 mm3) of Grade 15 and 20, embedded with 20 mm diameter of rebar were immersed in 120g/l NaCl concentration for 42 days (G15N and G20N). Other samples were left immersed for 20 days and the corrosion process is accelerated by connecting the rebars to a direct current supply (G15E and G20E). Results show that the amplitud at fst for G15N reduces 21% from the 20th day of immersion to the 42nd day and 24% for G20N. For the samples that had undergone accelerated corrosion process (G15E), the fst amplitude reduction from day 14th of immersion to day 20th is 15% and 18% for G20E. The percentage reductions of electrical potential in the half-cell test are 52%, 50%, 28% and 16% during the same time duration. It can be seen that the amplitude attenuation measurement can determine the corrosion activity of the steel rebars. The overall reductions of amplitude are 46% (G15N), 43% (G20N), 54% (G15E) and 52%(G20E) respectively.
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8. Pengesanan Kerosakan Gentian dalam Rangkaian FTTH Menggunakan Sistem Pengesanan
Kerosakan Terpusat (CFDS) (Detection of Fiber Fault In FTTH Networking Using the Centralized Failure Detection System (CFDS))
Mohammad Syuhaimi Ab-Rahman, Ng Boon Chuan & Kasmiran JumariAbstract
Issues with fiber fault in fiber to the home (FTTH) customer access network often become a challenge to the network service providers. The most important issues troubled the service providers and customer premises are regarding the service reliability and safety. Conventionally, optical time domain reflectometer (OTDR) is used to detect the fiber fault and address the failure location in FTTH upwardly from customer sides toward central office (CO). However, OTDR can only display a measurement result of a testing line in a time and also time and cost misspend. By looking at the stated issues, a simple, attractive and user friendly graphical user interface (GUI) is developed for Centralized Failure Detection System (CFDS) based on MATLAB programming in this study. The developed program will be installed with optical line terminal (OLT) at the CO to centralized monitoring each optical fiber line’s status and identifying the failure location that occurs in the drop region of FTTH downwardly from CO towards customer sides. CFDS is interfaced with OTDR to accumulate every network testing result to be displayed on a single computer screen for further data analyzing. The analysis results will be sent to field engineers or service providers for promptly actions.
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9. Penspesifikasian dan Pengesahsahihan Formal Protokol CSMA/CD Menggunakan Z (Formal Specification and Verification of CSMA/CD Protocol Using Z)
Zarina Shukur, Nursyahidah Alias, Bahari Idrus & Mohd Hazali Mohamed HalipAbstract
This paper discusses the formal specification and validation for CSMA/CD protocol. The Z specification language is used to specify a node in a network and a situation in a bus implementation for CSMA/CD protocol. One basic type, four free types, one global variables, two state schemas and nine operation schemas that represent CSMA/CD protocol have been specified by using the Z language. The specification has been validated by using theorem proving techniques supported by Z/EVES theorem prover. Nine theorems have been identified based on the nine specified operations. This study has shown that, Z has the ability to specify a communication protocol. Beside that, the usage of support tools during a proving process can save time dan energy, and reduce error-prone.
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10. Rekabentuk Peranti Pemisah-Gabung Optik 2×3 Berasaskan Pandu Gelombang Planar (The Design of 2×3 Optical Splitter-Combine Based on Primary Planar Waveguide)
Mohammad Syuhaimi Ab-Rahman, Norazilawati Md-Zain, Siti Rahayu Hassan & Kasmiran JumariAbstract
In this paper, we present the design of 2×3 optical splitter-combine based on waveguide with SU-8 polymer material. The technology ensures low cost fabrication and excellent performance as compared to conventional technique that uses fused coupler for optical splitter fabrication. The optical splitter-combine is suggested to be used in passive customer access network FTTH-PON to variety the signals send to the premises. It is the first time reported. The problems arose such as the loss of output power is also discussed. The simulation result shows that various factors; namely the width of waveguide, refractive index and wide-angle branching will increase the output power loss. To obtain maximum power, the optimization of those parameters’ value must be used. This designed optical splitter is operated at wavelength 1500 nm – 1600 nm. In this study, we characterized the trend of total output power with the effect of the parameters studied.
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11. Kesan Halaju Putaran Gilapan Terhadap Peratus Potongan Hujung Sisi Pandu Gelombang
Polimer SU-8 di atas Substrat Silikon (The Study of the Effects of Polishing Rotation Speed to the Length of Cut End Face SU-8 Polymer on Silicon Substrate)
Mohammad Syuhaimi Ab-Rahman, Fazlinda Ab Aziz, Noor Azie Azura Mohd Arif, Abang Anuar Ehsan & Kasmiran JumariAbstract
This research have focused on polishing characterize of polymer based waveguides. The aims of this research are to study how polishing rotation speeds affect the length of cut end face SU-8 polymer on silicon substrate. There are seven sets of rotation velocities which are 50, 100, 150, 200, 250, 300, and 350 rpm. From the obtained result, it can be concluded that percentage of cut length for each rotation velocity is ≤ 0.5 % (50 rpm), 0.6 – 1.0 % (100 rpm), 3.8 – 4.8 % (150 rpm), 7.7 – 10.6 % (200 rpm), 15.7 – 18.3% (250 rpm), 25.6 – 27.4 % (300 rpm) and 40.0 – 43.7 % (350 rpm).
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