Repository@USM
Welcome to closed access digital repository of Universiti Sains Malaysia (USM).
This repository contains multiple types of scholarly materials, especially USM theses and exam papers.
To access the full text, please log in with your USM email account.
Research outputs
3838
Projects
0
People
0
Recent Additions
- PublicationMAA 161 - Statistics for Science Students(2022-08)Second Semester Examination 2021/2022 Academic Session August 2022 MAA 161 - Statistics for Science Students Duration: 2 hours
- PublicationMAA 101 – Calculus for Science Students 1(2022-07)Second Semester Examination 2021/2022 Academic Session July 2022 MAA 101 – Calculus for Science Students 1 Duration : 2 hours
- PublicationMAT161 – Elementary Statistics(2022-02)First Semester Examination 2021/2022 Academic Session FEBRUARY 2022 MAT161 – Elementary Statistics Duration : 2 hours 45 minutes
- PublicationMAT100 - Mathematical Foundations(2022-02)First Semester Examination 2021/2022 Academic Session February 2022 MAT100 - Mathematical Foundations Duration : 2 hours
- PublicationMAA161 - Statistics for Science Students(2022-02)First Semester Examination 2021/2022 Academic Session February 2022 MAA161 - Statistics for Science Students Duration : 2 hours
Most viewed
- ItemImplementing wavelength division multiplexing for high speed FDDI network(2002-01)The advance in Wavelength Division Multiplexing (WDM) technology has tremendously increased the bandwidth of a single fiber optic. For a local and metropolitan are network (LAN and MAN). FDDI network offers an excellent network resiliency, good Quality of Services (QoS) and high network throughput. These two technologies if combined can offer a network with all excellent performance and higher reliability. By implementing WDM in FDDI will give an approximately N times network throughput offered by conventional FDDI network within a single channel The value of N depends on the number of channels that can be supported in the network. The' number of channels is equal to the number of wavelength used in the network. This thesis presents and discusses a new network architecture, which combined conventional FDDI with WDM to decrease the maximum access delay and increase the throughput over different network configurations. This n~twork is called FDDIIWDM operate over multiple non-overlapping channels, with each channel operating independently on a different wavelength. Each station wilLuse an-interfacing unit to operate over multiple wavelengths channel The performance of IDDIIWDM network operating over different number of wavelength channels is evaluated with different network parameters under heavy load for asynchronous traffic, using discrete event simulator called OMNET ++. Network parameters used are TfRT, total fiber length, number of active stations, frame size. The study shows that FDDIIWDM gives a higher throughput (almost IGbps on 10 channels network) and less delay (- lOOms on 10 channels network) compared to the standard standard FDDI network. Network performance increasing as the number of channels is increased. Furthermore, to achieve higher performance network parameters (i.e. TTRT, total fiber length, number of stations) should be selected carefully.
- PublicationDeformation Monitoring Of Marwat-Khisor Ranges, Pakistan Using Interferometric Synthetic Aperture Radar(2023-02)Main Frontal Thrust (MFT) represents the southern boundary of Himalaya, which accommodated the current orogeny of Eurasian-Indian tectonic plate’s convergence. The deformation pattern and structural style of MFT are crucial for understanding the tectonic activities. A chain of fold-and-thrust (FAT) belts (Salt-Trans Indus Ranges) are identified as the MFT in the western Himalaya. The Salt Range had propagated southward at an average rate of 5-10 mm/year in the influence of salt tectonics. Although the Trans Indus Ranges had indicated an active Quaternary tectonics, the fault slip rate and direction was unknown. This study focused on the Marwat-Khisor Ranges (a segment of Trans Indus Ranges), the youngest part of the MFT in the western Himalaya. Remote sensing techniques such as Interferometric Synthetic Aperture Radar (InSAR) Permanent Scatterer (PS), lineament extraction and geometric analysis of salient were implemented to investigate the deformation mechanisms and active tectonics. InSAR processing of 80 Sentinel-1 images showed the Marwat-Khisor Ranges were uplifting in the satellite line-of-sight at an average rate of 3-7 mm/year dated from 18th October 2014 to 18th June 2019. The Marwat-Khisor Ranges are the hanging wall sequence that ramped up section above the partially emergent Khisor Thrust where surface uplift is expected.
- ItemDynamic modeling and optimization of batch electrodialysis process for hydrochloric acid recovery(2009)Electrodialysis is a feasible method for acid recovery because it has the capability of separating ionic chemicals from non-ionic chemicals in process or waste streams to achieve product purity or eliminate wastes. At the same time, it can also concentrate the separated chemicals involved. Optimum operating conditions are very important for the electrodialysis process to ensure maximum ED performances. To obtain those optimum operating conditions, an optimization technique using mathematical models was implemented. The Nernst-Planck derived relationship was used to build the dynamic process model which contains set of ordinary differential equations (ODE). A degree of freedom analysis was carried out with 38 unknown parameters were identified. The parameters were determined from the literature and various equations. The developed model was then simulated and the results were compared to Lindheimer et al.’s (1993) experimental work. The high accuracy of the developed model was achieved with 99% degree of confidence. The sensitivity analysis of various ED parameters towards its performances was analyzed. The results showed that process time and energy consumption increased when the higher initial HCl concentration in the dilute and concentrate tanks, higher current density and lower V In order to obtain optimal control trajectory, the dynamic optimization problem was applied using a simultaneous approach i.e. the orthogonal collocation method, where the differential variables were fully discretized. This was implemented within the MATLAB® environment by using the dynopt code package. Five objective functions were used in this study: minimize process time (P1), minimize the dilute concentration (P2), minimize energy consumption (P3), maximize degree separation (P4) and maximize operation profit (P5). From the simulation results, it was found that the control trajectories of P5 was chosen to be the most effective control operation in order to achieve the minimum process time for 99% degree of separation. The control trajectory achieved was reliable and practical. Moreover, the process time achieved for P5 was 51.6% faster than the P2, 60.67% faster than P3 and 7.9% faster than P4. The profit and energy consumption of P5 that were achieved were RM 18.54/batch and 780.202 Wh respectively. The study on the effect of different aspects of optimization towards ED performances was also carried out. Based on the results, it can be concluded that the effective number of interval, number of state collocation and trajectory type for this study was five, three and piecewise continuous linear respectively.conc/Vdil ratio were applied. However, the effect of flowrate towards process time and energy consumption was not significant.
- ItemA Brief History Of A Smelting Company With Reference To The History Of Malaysian Tin Industry 1869 - 1966(Universiti Sains Malaysia, 1974)Our research was mainly concentrate at the company office at 73, Dato Keramat Road, Penang. The necessary secondary background was done at the university’s Library at the Minden and also at the company’s Library.
- ItemThe Study Of Semiochemicals And Their Application In The Control Of Aedes Aegypti (Linnaeus)(Universiti Sains Malaysia, 2013-12)In the present study, the attract-and-kill strategy was demonstrated in the larva and adult of Aedes aegypti. The two components in the strategy: attractant and killing agent were determined and bioassay of the combination to Ae. aegypti was carried out. In the larval stage, extraction of the Ae. aegypti oviposition pheromone was performed using fatty acid extraction and modified methanolic extraction from the eggs of Ae. Aegypti (lab strain) from Vector Control Research Unit (VCRU), University Sains Malaysia. Fourteen compounds were identified by fatty acid while eight compounds were identified by modified methanolic extraction. Among these, four compounds (palmitoleic acid, caproic acid, palmitic acid and fumaric acid) were investigated for their attractiveness to gravid female Ae. aegypti; 1ppm caproic acid significantly attracted more gravid female Ae. aegypti to lay eggs (660.83±91.61) than the control (343.83±56.24). Combination of caproic acid with granules temephos as a lethal lure has significantly attracted more gravid female Ae. aegypti to oviposite their eggs (835.40 ± 94.23, P>0.001) than the control (538.30 ± 74.50, P>0.001) and the presence of temephos restricted the hatching of the eggs and kill the progeny when the larvae hatched. Meanwhile, host-seeking behaviour of female Ae. aegypti is influenced by various cues in which odours play major part in this behaviour. The attractiveness of several kairomones: L-lactic acid, ammonia, acetone and acetic acid were tested in its individual and binary combinations. Ammonia-acetone and ammonia-acetic acid significantly attracted more female Ae.