Volume 27 (2015)

Table of Contents

No. Article Page  
1. Factors that Affect Cycling Transportation Mode for Postgraduate Students at Universiti Kebangsaan Malaysia by Logit Method
Sahar Abd Ali Dawood & Riza Atiq bin O.K. RahmatAbstract
The main aim of this study is to investigate the factors that affect cycling transportation mode and give suggestions to encourage students to use these facilities to decrease the use of motorized transportation. Firstly we chose the Universiti Kebangsaan Malaysia (UKM) campus as an example for our study which focused on shifting from motorized transport to non-motorized especially to cycling transport. Our study involved conducting a survey on postgraduate students at 1st semester (2013-2014). A total of 169 questionnaires were distributed personally inside the campus and interviews were done with the students. Our survey showed that the majority of postgraduate students were tending to use car with percentage of 45.5% and 38.4% prefer using the bus followed by 12.4% using motorcycle and the least percentage using bicycles with percentage of 3.5%. The most effective factor in shifting postgraduate students who use cars and motorcycles to use bicycles is imposing fees on parking inside UKM and limiting the space for parking. The decrease in the number of buses inside campus and imposing fees on buses have high effectiveness in switching students who use the bus to cycling transportation.
DOI : dx.doi.org/10.17576/jkukm-2015-27-01
2. Voltage Constrained Optimal Power Flow Based Using Genetic Algorithm
Yassir & Teuku HasannuddinAbstract
Voltage constrained of Optimal Power Flow (OPF) is one of several methods to minimize fuel costs while maintaining system reliability constraints. In this study, Genetic Algorithm (GA) was applied to solve the problem of OPF. Active power generator, generator-buses voltages, transformer tap and injection capacitor are used as control parameters. Effectiveness of the proposed method was tested on IEEE 30 bus system and it has been compared to other optimization of power fl ow using other methods, for example the Evolutionary Programming (EP), Differential Evolution (DE) and Particle Swarm Optimization (PSO) methods. Simulation results of the three-phase voltage profile along the tested feeder using the proposed method provide better results than other mentioned methods. Before applying the proposed method, voltage profile on bus 12 (load-buses) is equal to 1.058 p.u, which is beyond the acceptable limits. However, after applying the proposed method, it improved the voltage profile at bus 12 to be within the acceptable limit, which is equal to 1.045 p.u.
DOI : dx.doi.org/10.17576/jkukm-2015-27-02
3. Modelling of Transportation Policies to Encourage Shifting from Private Car to the Public Transport Usage in Putrajaya
Amiruddin Ismail & Haider Farhan HashimAbstract
The rapid growth of car ownership in Malaysia has led to a number of problems such as air contamination, traffic jams, numerous accidents, extensive fuel consumption and greenhouse effect. The proper solution is by increasing awareness about it and transferring to public transport. This paper includes vast information concerning main differences between workers who use train, bus or their car to go to work to Putrajaya administration area. It also contains information about creating transportation policies meant for encouraging car owners to start using bus on a regular basis. The survey lasted for more than one month and it included 220 respondents who needed to fill out three parts of the questionnaires and provide main travel characteristics, personal information, and name strategies that would inspire people to start using buses on a regular basis. The prime goal of this research is to use logistic regression for creating a model that would illustrate the transfer by using few variables such as gender, age, the level of education, occupation, travel time and cost, as well as car ownership. Education level and occupation were two most important factors that would show the possibility of shifting to public transport. The percentage of respondents who preferred using their own car to go to work or run errands is rather high at 86.1% on average. After that, there is 8.9% of bus travellers and 5% of train travellers. However, 70% of car users stated that they would use a bus in case of decreased time of bus travel and increased parking charges to RM 5 per hour.Keywords: Cars ownership; public transport; traffic congestion; traffic modelling
DOI : dx.doi.org/10.17576/jkukm-2015-27-03
4. Modelling of Elastic Modulus Degradation in Sheet Metal Forming Using Back Propagation Neural Network
M. R. Jamli, A. K. Ariffin & D.A. WahabAbstract
The aim of this study is to develop an elastic modulus predictive model during unloading of plastically prestrained SPCC sheet steel. The model was developed using the back propagation neural networks (BPNN) based on the experimental tension unloading data. The method involves selecting the architecture, network parameters, training algorithm, and model validation. A comparison is carried out of the performance of BPNN and nonlinear regression methods. Results show the BPNN method can more accurately predict the elastic modulus at the respective prestrain levels.Keywords: Back propagation; elastic modulus degradation; neural network
DOI : dx.doi.org/10.17576/jkukm-2015-27-04
5. Analysis of Damper Effect on Cable-Stayed Bridge Using Finite Element Simulation
Chai Mei Hwa & Siti Aminah OsmanAbstract
Cable-stayed bridges generally having common defects such as excessive vibration due to wind action, corrosion and fatigue occurred at the cables supporting member. This study presents two different approaches for the demonstration of the damping effect due to wind action on cable-stayed bridge. The first approach uses a simplified analysis method to study the reaction force at the cable end. A beam element was adopted for modelling the cables and a plate element for modelling the bridge’s deck. The second approach is based on the selected damper system applied at the cable end to determine the reaction response at the bridge models. Two methods are presented in this report with the consideration of bridge geometric effect. The effect of pretension of the cable and the exact treatment of cable sag with the cable weight is ignored. A numerical calculation has been carried out in determining the nominal transverse wind load, the nominal longitudinal wind load on deck and the nominal longitudinal wind load on cables in accordance to the current code of practice. The results generated from MIDAS Civil software have been used for comparing the analysis results. The stiffness coefficient for the selected rubber damper type was being modelled at the cable end to examine the effect of nominal and combined wind action at critical locations. The effectiveness of using the rubber damper to suppress the effects of wind was investigated through superposition of these rubber dampers at the maximum reactions at the cable end. It was found that the damper system adapted on the cable-stays has significant influence on suppressing the action due to wind.Keywords: Cable-stayed bridge; rubber damper; MIDAS Civil
DOI : dx.doi.org/10.17576/jkukm-2015-27-05
6. Kajian Model Penukaran Kadar Hujan untuk Integrasi Masa 60 Minit kepada 1 Minit di Malaysia (Study on Rainrate Conversion Models for 60 Minutes to 1 Minute Integration Times in Malaysia)
Nor Irza Shakhira Bakhtir & Mandeep Singh Jit SinghAbstract
The rapid development of wireless communication technologies has led the frequency band reach its saturated level, particularly in developed countries. This has drawn the attention of telecommunication systems engineer to explore the frequency band above the Ku band (10 GHz). However, raindrops significantly affect the signal propagating in the frequency bands above 10 GHz. Thus, prediction of rain attenuation on the propagation of electromagnetic signals using 1 minute rainfall rate is important. In many countries, 60 minutes rainfall rate distribution are widely available compared to rainfall rate distribution with shorter integration times. Therefore, conversion method is essential to predict 1 minute rainfall rate distribution from 60 minutes rainfall rate distribution. This study was conducted using rainfall data from 10 stations of Malaysia Drainage and Irrigation Department over 3 years period of 2011 to 2013 to determine the best conversion model for 60 minutes rainfall rate in Malaysia. Several conversion models is presented in this study such as Segal, Burgueno et al., Chebil and Rahman, Lee et al., Lavergnat and Golé and Moupfouma and Martin. From the results, Chebil and Rahman’s model is found to be the most suitable model to be used in Malaysia with Root Mean Square (RMS) error below 20% for all locations. This project is very useful to determine rain attenuation in designing a high availability and accessibility satellite communication system.Keywords: Integration time; rainfall rate distribution; conversion method
DOI : dx.doi.org/10.17576/jkukm-2015-27-06
7. Assessing the Contribution Factors for the Enhancement of Green Building Index (GBI) in the Malaysian Construction Industry
Yeong Liang Sim, Frederick Putuhena, Puong Ling Law & Azhaili BaharunAbstract
This research paper focuses on the several most crucial organisation factors that directly influence the Green Building Index (GBI) in the Malaysian construction industry. The findings of the paper are based upon a comprehensive literature search and empirical studies conducted with 102 construction firms in Malaysia. All these firms are selected based on firm sizes of 50 people and above within the organisation. Seven internal organisation factors are correlated with five external factors for the improvement of the green construction organisation. The study used Canonical correlation methods to correlate simultaneously the internal factors to the assessment of the improvement for the organisation. In summary it can be stated that the overall level of organisation factors are medium and there are rooms for improvement. The most important internal factors that influence the Malaysian construction projects were found to be ‘Environmental/Green Technology’, ‘Training’ and ‘resistance to change. The least important factors were documentation and usage of computer technology. On the other hand, external factors that influence projects green performance were found to be ‘Integration with Environmental Management’, ‘New Approaches to Management’ and ‘Shifting Customer Expectations’ The findings suggest that the integration of several factors as the preferred option for the enhancement of the green performance within the Malaysian Construction Industry. Senior Management can utilise these factors to assess their strengths and weaknesses on the organisation practices necessary for the effective deployment in construction projects.Keywords: Green building index (GBI); green technology; organisational factors; environmental management; construction
DOI : dx.doi.org/10.17576/jkukm-2015-27-07
8. Solvent Extraction of Light Rare Earths from Acidic Medium by Di-(2-ethylhexyl) Phosphoric Acid in Kerosene
Khaironie Mohamed Takip, Masturah Markom & Meor Yusoff Meor SulaimanAbstract
An organophosphorus reactant, D2EHPA, in kerosene has been employed as an extractant for solvent extraction of a mixture of light rare earths (La(III), Nd(III) and Ce(IV)) from acidic nitrate and sulphuric medium. Effect of various concentrations of acidic solutions and extractant on the extraction of rare earths was investigated. The experiments were carried out under various concentrations of aqueous phase of acidic solutions (0.1-0.5 M) and organic phase of D2EHPA (0.1-1 M) at organic-to-aqueous (O/A) phase ratio of 1. The effect of temperature on extraction was also studied by varying temperature range from 278 to 318 K. Extraction equilibrium time was investigated to determine the optimum time for extracting the studied rare earths. It was found that the extraction of 99.4%, 99.7% and almost 100% for La(III), Nd(III) and Ce(IV), respectively, was achieved from 0.1 M HNO3 feed solution with 1 M D2EHPA at room temperature. The process showed that the selective extraction was in order of La(III)<Nd(III)<Ce(IV). The loaded organic was stripped with various concentration of several acidic solutions (HCl, HNO3 and H2 SO4 ) at O/A phase ratio of 1. It was found that the recoveries of La(III) and Nd(III) to the strip liquor were relatively moderate (45.2-67.7%), whereas losses of Ce(IV) were very low (><1.5%).Keywords: D2EHPA; rare earth; solvent extraction; stripping> to the strip liquor were relatively moderate (45.2-67.7%), whereas losses of Ce(IV) were very low (<1.5%).Keywords: D2EHPA; rare earth; solvent extraction; stripping
DOI : dx.doi.org/10.17576/jkukm-2015-27-08
9. Pemodelan Hubungan Antara Kualiti Perkhidmatan, Kesan Alam Sekitar, Sikap dan Keinginan untuk Menggunakan Park-and-Ride (Modelling of Relationship Between Service Quality, Environmental Impact, Attitude and Intention to Use Park-and-Ride)
Muhamad Nazri Borhan, Norliza Mohd Akhir, Amiruddin Ismail & Riza Atiq Abdullah O.K. RahmatAbstract
Structural equation modelling (SEM) is a modelling technique that can handle a large number of endogenous and exogenous variables, as well as latent variables specified as linear combinations of the observed variables. Usually, the estimation method used in the modelling analysis is the maximum likelihood (ML) estimation. In this study, the park-and-ride (P&R) usage model was developed to estimate the direct effects, indirect effects and overall impact on the studied phenomenon. Based on the proposed conceptual framework, the full structured models were proposed and tested, thus the significant predictors were identified based on the statistical significance for all paths in the model. The findings revealed that almost all causal relationships were statistically significant. Implications for all predictors were also discussed in this study.Keywords: Structural equation modelling; P&R; maximum likelihood
DOI : dx.doi.org/10.17576/jkukm-2015-27-09
10. Lagrangian Investigation on the Compound Effects of Reclamation and Proposed Tidal Barrage to the Environmental Flow
Wei-Koon Lee & Nur Hidayah Aqilla ZaharuddinAbstract
Large-scale reclamation at Tekong Island, Singapore and the construction of a tidal barrage across Johor River in Kota Tinggi is expected to alter the local hydrodynamics in Johor River Estuary (JRE) and East Tebrau Strait (ETS). Using flow field generated from a set of hyperbolic shallow water equations solved on hierarchical quad tree grid system, Lagrangian particle tracking is performed to examine the individual and combined effects of the above developments on particle fate. Results show that particle escape is highly dependent on the tidal cycle and the initial positions. Stretching of particles is observed in all cases, whereas dispersion occurs only in ETS. While the flushing effect in JRE is enhanced after the completion of the above projects, the resident time of particles released in the ETS increases, suggesting potential environmental threat to the already polluted water body.Keywords: Johor Estuary; Langrangian tracking; Tebrau Strait; Tekong Island
DOI : dx.doi.org/10.17576/jkukm-2015-27-10
11. Study on Drivers’ Behaviour Relationships to Reduce Road Accidents in Puchong, Selangor Darul Ehsan
Amiruddin Ismail, Gan Soon Yi & Mohd Kamarul Ifzam Mohd ZainAbstract
Road accidents are the most common phenomenon in our daily life which occurs in every part of the world. In Malaysia, these issues took away many precious lives despite causing problems to the living family. Based on the Global Status Report, World Health Organisation (WHO) on Road Safety, Malaysian road users are categorized as the worst in South East Asia with an average of 23.8 deaths per 100,000 populations. One of the main factors that contribute the issue is drivers’ behaviour. Moreover, this study was conducted to investigate the relationship between drivers’ attitude towards road accidents in urban areas. Puchong in Selangor was selected and identified to have numerous cases of road accidents. Descriptive data of road accidents in Puchong were analysed to gain the results in graphical and numerical form. The causes of road accident due to driving’s behaviour were verified through the developed drivers’ behaviour model. A related suggestion has been stated based on this study to reduce and prevent the road accident at the studied area.Keywords: Drivers’ behaviour; road accidents; drivers’ behaviour model
DOI : dx.doi.org/10.17576/jkukm-2015-27-11
12. Optical Properties of Fe2+ Ion Doped ZnS Nanoparticles Synthesized Using co-Precipitation Method
Rahizana Mohd Ibrahim, Masturah Markom & Kamal Firdausi Abd RazakAbstract
Nanoparticles of Zn1-xFex S (x = 0.0, 0.1, 0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure and optical properties of nanoparticles was undertaken. Structure, elemental analysis and optical properties have been investigated by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), UV-Visible Spectroscopy and photoluminescence (PL) spectrophotometer. FT-IR and XRF results confirmed the incorporation of ion dopants into ZnS crystal structure, and XRD results showed that Zn1-xFex S (x = 0.00 and 0.10) nanoparticles crystallized in a zinc blende structure without any impurity. The particle size of all of samples ranged from 2 nm to 3 nm, as calculated by the Debye-Scherrer formula. The optical absorption spectra indicate a blue shift of the absorption edge with increasing Fe-content. The luminescence of nanoparticles excite at about 370 nm with an emission peak at around at 452 nm, 490 nm and 550 nm.Keywords: Nanoparticles; ZnS:Fe2+; Sodium Hexamethaphosphate; luminescence
DOI : dx.doi.org/10.17576/jkukm-2015-27-12
13. Pemodelan Kesediaan Pelajar Beranjak kepada Berbasikal di UKM (Modelling of Student Readiness Switch to Cycling Modes at UKM)
Sahar Abd Ali Dawood, Muhamad Nazri Borhan & Riza Atiq RahmatAbstract
Increasing dependence on the use of cars and sedentary lifestyle in the university campus have resulted in growing traffic congestion and more demand for parking, air pollution, and many others. Therefore, many studies were carried out to fulfill the requirement for sustainability in the university campuses. The term of “Active Transportation” such as cycling needs to be a way to acquire sustainability in the university campuses. In order to evaluate the impact of this measure, a total of 169 questionnaires were distributed personally inside the campus to the car drivers and interviews were conducted among the students in National University of Malaysia (UKM). Logistic regression is used to analyses the factors that influenced users to switch their mode choice to cycling. It is concluded that implementing parking fee and limiting parking area will directly affect the cycling activity inside the campus.Keywords: Cycling; university campus; active transport; UKM
DOI : dx.doi.org/10.17576/jkukm-2015-27-13
14. Kejituan Datum Carta dalam Tempoh Cerapan Pasang Surut: Kajian Kes di Teluk Ewa, Pulau Langkawi
(An Accuracy of Chart Datum in the Tidal Observation Period: Case Study for Teluk Ewa, Pulau Langkawi)

Khairul Nizam Abdul Maulud, Zaaim Hasan & Othman A. KarimAbstract
This study elaborates the precision of chart datum at Teluk Ewa, Langkawi Island. Observed tidal data for 19 years at Teluk Ewa tidal station were processed and analyzed using the “RMN Asean Australia Tidal Software” to determine values of chart datum for 19 years observation models (Reference datum), yearly, 6 monthly, 3 monthly and monthly. Datum precisions were tested conforming with International Hydrographic Organization (IHO) Standard. IHO had determined that datum error for special class survey must be less than 5 cm and 10 cm for first class survey and below. Results showed that the standard deviations (one sigma) for all model of chart datum are less than 10 cm, however at two sigma it proved otherwise. The trend of chart datum standard deviation indicated that longer period of observation record better standard deviations. Tides are site specific, therefore holistic approach of the country’s chart datum precision could only be modeled once the studies on all tidal stations are completed.Keywords: Bandwidth; phase range; phase slope; triangular loop; transparent conductive film
DOI : dx.doi.org/10.17576/jkukm-2015-27-14
103 -109