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- PublicationReal time algorithm for the portable recording of fetal and maternal heart rates(2000)
;Ahmed Firoz ;Ali M.Alauddin Mohd ;Zahedi Edmond ;7202460653 ;65074166666603591267A PIC17C44 microcontroller development board and a real-time algorithm were developed with the capability of monitoring the fetal heart rate (FHR) as well as recording both the FHR and maternal heart rate (MHR) for 24 hours. This paper describes the implementation of the real-time algorithm by using the development board which is used to develop the portable recorder. The signal processing algorithm processes the abdominal electrocardiogram (AECG) signal which is sensed via a single pair of electrodes and continuously detect both the fetal and maternal QRS complexes for the measurement of the heart rates. The algorithm detects the MECG complexes and removes these from the AECG signal for enhancing the fetal QRS complexes. The average performance of the algorithm is 70%. It is based upon digital analysis of slope, amplitude and width of the signal. It automatically adjusts thresholds and parameters to adapt to such ECG changes as the QRS morphology and heart rates. The results acquired by the developed algorithm are also here.2 - PublicationSintering behaviour of slip-cast Al2O3 - Y-TZP composites(Kluwer Academic Publishers, 2000)
;Ramesh S. ;Siah L.F. ;Nor Azmah A.K. ;41061958200 ;86108580006504069879The sintering behaviour of alumina-Y-TZP composites prepared by slip-casting technique were studied. Slip-cast samples containing varying amounts of Y-TZP ranging up to 90 vol% were prepared and evaluated. Sintering studies were carried out at 1450 �C to 1600 �C. Sintered samples were characterized where appropriate to determine phases present, grain sizes, bulk density and mechanical properties. Good correlation was obtained between the calculated prepared powder density and experimental results. The sintered bulk density of the composites was observed to increase with increasing Y-TZP content and sintering temperature up to 1550 �C. Maximum hardness values (>14 GPa) were obtained for all samples containing >60 vol% Y-TZP and when sintered at 1550 �C. It has been found that the additions of up to 50 vol% Y-TZP was effective in suppressing Al2O3 grain growth.3 - PublicationUltrasound micro-power meter(2000)
;Ong H.S. ;Ritenour E.R. ;160230444007003924569Novel ultrasound imaging procedures such as harmonics imaging and power Doppler imaging have increased the amount of ultrasonic energy deposition into patient body tremendously. Two safety indices, Thermal and Mechanical Indices, have been proposed to address this concern. Accurate value of ultrasound power output is required in order to calculate the indices. Therefore, this give rises to the need for a device that is capable of measuring ultrasound output power quickly and accurately. In this paper, a micro-power meter, a dual chamber heat conduction calorimeter (HCC) is designed, built and tested for the purpose of measuring ultrasonic output power of clinical diagnostic ultrasound devices. The dual chamber heat conduction calorimeter (HCC) is composed of two identical water filled Aluminum wells housed in two separated compartments of an insulated box. The two compartments form the measuring and reference chambers of the calorimeter. The wells are sealed with plastic membranes that constitute the entrance window for the ultrasound. The bottom of each well is stuffed with a 4 cm layer of 0.5 cm thick rubber pads. These pads serve as a sonic-to-heat energy exchanger. A small resistive heater is embedded in both rubber pads for calibration purposes. Heat is measured with a series of Seebeck effect thermoelectric devices (thermopiles) sandwiched between the well and the heat sink surrounding the wells. The output voltage signal from the thermopiles is amplified, digitized, then analyzed and displayed in term of Thermal Index with a PC-based system. The performance and sensitivity of the HCC is tested and measured, initially with the embedded resistive heaters, then with an experimental transducer, and lastly with transducers from clinical ultrasound scanners.5 - PublicationDevelopment of a portable fetal and maternal heart rate recorder for 24 hours(2000)
;Ahmed F. ;Alauddin M. ;Ali M. ;Zahedi E. ;7202460653 ;7007114966 ;65074166666603591267This paper focuses on developing an ambulatory system capable of monitoring the fetal heart rate (FHR) as well as recording the FHR and maternal heart Rate (MHR) for 24 hours by two-development work. The first is a microcontroller board which uses three electrodes, to sense the abdominal electrocardiogram (AECG) signals and then process the signal for monitoring FHR and recording the fetal and maternal RR intervals for 24 hours. The RR intervals are recorded inside the external memory of the board for downloading into a PC through an RS232 interface. The board accommodates of a PIC17C44 microcontroller chip, address interface, SRAMs, ADC circuit, amplifier circuit, power supply circuit, RS232 interface circuit and display interface circuit. The second development is the appropriate algorithms for extracting the heart rates from the AECG. The algorithms detect the maternal and fetal R waves by using their respective matched filters and adaptive thresholding schemes, whilst the maternal electrocardiogram (MECG) is subtracted by an appropriately scaled template obtained from an averaging process. Then the ambulatory system for monitoring the FHR and recording the RR intervals is constructed. The size of the recorder is 5 inches � 4 inches. Post-processing software have also been developed on the PC to simultaneously display both heart rate traces. The real data from several patients have also been presented in this paper.2 - PublicationLevel control experiment via Internet(2000)
;Salleh Hanim ;Yusaf Talal F. ;Azlan M.Khafif Zol ;24067645400 ;231120659006503929041This project is a result of a number of tests and experimental work that been carried out at the UNITEN laboratory to control the water level via Internet (using LabVIEWTM). The experimental setup consists of water tank, sump, level sensor, proportional valve and centrifugal pump. The computer data acquisition and control system use plug-in module which consist of a converter, a digital input/output module, an analog output module and an analog input module. This project also represents the first phase of controlling and operating stationary single cylinder four stroke diesel engine.3 - PublicationLoss reduction via load balancing single phase versus three phase connectivity(2000)
;Khan Sheroz7404043105Electric load management with single and three phases was analyzed as per customer requirements. The electric losses of unbalanced networks were calculated. Balancing of three phase saved the electric energy and optimized usages. Single phase connectivity for residential consumers was found preferable in all contexts.1 - PublicationContamination of high voltage insulators in the east coast of Peninsular Malaysia(Institute of Electrical and Electronics Engineers Inc., 2000)
;Ahmad A.S. ;Ahmad H. ;Jidin R.B. ;Tamsir T. ;Ahmed S.S. ;Buntat Z. ;7202040740 ;7102866725 ;6508169028 ;7801658692 ;5719373577657194234727Rapid urbanization and industrialization in Malaysia over last two decades has resulted in increased demand for reliable electric power. The reliability in turn is greatly influenced by the grid system and its components being properly maintained. One of the important components is the high voltage insulators used in the switchyards, overhead lines, substations and power stations. A common phenomenon in the east cost of Peninsular Malaysia is rapid buildup of salt contamination on high voltage insulators due to the salty wind coming from the South China Sea. The main objective of this paper is to develop a mathematical model correlating Equivalent Salt Deposit Density (ESDD) with the hydrometeorological variables. The data collected at one of the plants in the east coast during the dry season has been used to develop the model by using multiple regression analysis. This model has been validated for predicting contamination accumulation level during the dry season. � 2000 IEEE.7 - PublicationManagement information systems in higher learning institutes of Malaysia: An overview(2000)
;Jais Jamilin ;Rahman Zarina Abdul ;Hamid Suhaila Abdul ;Ibrahim Zailani ;Yusoff Mohd.Zaliman Mohd ;Hussain Hanafizan ;57212154525 ;7006355235 ;7006292762 ;7005685706 ;2263659020015077784900In Malaysia, Management Information System (MIS) is growing rapidly in most of the higher learning institutions, in line with the Government encouragement to make information technology (IT) as a part of our lives. Thus, a survey was carried out to oversee the roles and application of MIS in the higher learning institutions of Malaysia: emphasizing on managerial roles in decision making. Decision-making consists of stages that can be described as intelligence, design, choice, and implementation. In our survey twelve higher learning institutions are used to help identify factors/ activities involved in the first stage of decision making i.e. intelligence. From the survey, it was found that managers of higher learning institutions play a vital role in the implementation of MIS to enables business objectives and improve its productivity. Any management decisions made about IT are critically important since it will determine the prosperity and survival of the organization.5 - PublicationUsing design patterns in the development of a planner-based courseware system(2001)
;Al-Tahat K.S. ;Sembok T.M.T. ;Idris S.B. ;6508140157 ;92689004008230988900Design patterns have received a lot of attention recently, especially from the object-oriented community as a technique for design reuse. It has proved itself as an important piece that was missing from object-oriented design methods. Design patterns make it easier to reuse successful designs and architectures by providing solutions to common design problems at the abstract level. We have adopted an object-oriented development method complemented with design patterns in the development of a multimedia courseware system. The adoption of design patterns has helped us reuse software architectures and successful design experiences of design experts. In the system architectures, some design patterns are used only once, while others are used more than once in different places. This paper introduces some uses of design patterns in the design of a multimedia courseware system to obtain a flexible and reusable architecture as well as some of our experience in applying design patterns and some points that we think should pay attention to.1 - PublicationBuilding low-cost intelligent building components with Controller Area Network (CAN) bus(2001)
;Hooi T.C. ;Singh M. ;Siah Y.K. ;Bin Ahmad A.R. ;6507178058 ;56259597000 ;2444886440035589598800Intelligent Buildings is a concept that was derived from Theory of AI and has recently being realized by the increasing coverage and reliability of telecommunication equipment and Information Technology. Many of the intelligent building systems however, are derived from either building automation technologies such as Profibus�, ASHRAE's BACNET� or home automation protocols like X10�, BatiBus�, EIB�, HomeBus�, CEBus� and perhaps the more remarkable Echelon's LonWorks�. Most of the networks mentioned above did not offer enough bandwidth for voluminous data except for BACNet, and Profibus. Robustness under harsh condition has yet to be addressed by the above technologies. This paper will look into the construction of Controller Area Network (CAN) bus network (a cost-effective communication bus for in-car electronics with up to 1Mbit/sec and is resilient to extreme heat and harsh environments) to support intelligent building requirements as well as solving the problem of low bandwidth and robustness.6 - PublicationElectric and magnetic fields associated with the use of elecrical power in the workplaces in underdeveloped countries(2001)
;Farag A.57208098840It is a modern fact of life that whether humans at work, at home, or at school, are all exposed to low frequency electric and magnetic fields (EMFs) produced by the generation, transmission, and use of electricity. Some human health studies suggest that there may be links between exposure to EMFs and certain types of cancer, primarily leukaemia and brain cancer. Some scientists doubt that this apparent connection between EMF exposure and cancer is real, as it is difficult to explain biologically and due to the inconsistency of the research results. Most agree that more information and researches are needed to resolve the issue about whether or not EMFs affect human health. Many developed and industrialized countries have initiated national EMF research efforts and programs and important study results are expected in the next few years. This paper provides a thorough investigation and information about EMF exposure in the workplaces in some underdeveloped countries such as Egypt, Saudi Arabia and other Gulf Countries. The paper describes what researchers have learned about typical EMFs exposures in various work environments and identifies sources of EMFs in various industries and workplaces in those countries. This information should help designers, decision-makers, workers and employers understand the scientific basis of the concerns and the uncertainties about EMF exposure and set the standards for such equipment exposures.2 - PublicationElectromagnetic fields policy implications for risk assessment(2001)
;Farag A. ;Hussain H. ;Said I. ;Ahmad A.S. ;57208098840 ;35607922800 ;93363174007202040740The goal of the electromagnetic fields research program is to provide information on the types and extent of human exposure to such fields, as well as guidelines and methods to measure, characterize and manage field exposures. This paper explores the implications of such research for the risk assessment. The policy implications of an exposure are explored after all the data have been gathered and reviewed. This paper shows how risk assessment, exposure assessment and engineering information can be "packed" to address concerns of contributors of EMF policy. It gives a basic decision tree outlining the types of decisions to be encountered. Decisions will have to be taken regarding mitigation options, the certainty of hazard, dose-response relationships and dose-frequency distribution after mitigation. Since risk is a multidimensional concept, therefore, issues concerning electric and magnetic fields need to be addressed by social and political actions beside exposure reduction.5 - PublicationLinear array beampattern gain optimization techniques(IEEE Computer Society, 2001)
;Nagi F.56272534200The work describes here uses optimization techniques to increase the gain of a uniform linear array's beampattern when some of its elements fails. The optimization criteria evaluates the weights of the remaining elements so as to restore the gain as closely as possible to the reference beampattern. LMS and goal programming methods are used to evaluate the weights of the remaining array elements. In the LMS algorithm the error between the reference and the iterated beampattern is reduced. In the goal attaining algorithm the goal of optimization is set to the reference pattern. The comparison between the two techniques reveals that in general the goal programming algorithm perform better in terms of the SNR of the beampattern beamwidths. � 2001 IEEE.4 - PublicationThe AGEB algorithm for solving the heat equation in three space dimensions and its parallelization using PVM(Springer Verlag, 2001)
;Sahimi M.S. ;Alias N. ;Sundararajan E. ;35561342900 ;227334030006507137436In this paper, a new algorithm in the class of the AGE method based on the Brian variant (AGEB) of the ADI is developed to solve the heat equation in 3 space dimensions. The method is iterative, convergent, stable and second order accurate with respect to space and time. It is inherently explicit and is therefore well suited for parallel implementation on the PVM where data decomposition is run asynchronously and concurrently at every time level. Its performance is assessed in terms of speed-up, efficiency and effectiveness. � Springer-Verlag Berlin Heidelberg 2001.5 - PublicationPhase stability and microstructural development of Y-TZP-doped hydroxyapatite(Institute of Biomedical Engineering, 2001)
;Ramesh S. ;Muralithran G. ;410619582006507602730Hydroxyapatite containing yttria-tetragonal zirconia polycrystals (Y-TZP) with different concentrations were prepared by using the conventional ball-milling technique. Samples prepared from these powders were compacted and sintered at three different temperatures (1250�C, 1400�C and 1600�C). The sintering behaviour of the composites were studied in terms of phase stability, densification and microstructural evolution. By X-ray diffraction, tetragonal zirconia as wall as HA was identified as the major phases in the composites. In addition, small diffraction peaks corresponding to ?-TCP was evident indicating sign of HA decomposition. Reaction between the zirconia and HA to form CaZrO2 was also detected in the composite system containing up to 20 wt% Y-TZP.SEM examination of the sintered composites at room temperature suggested the involvement of a reactive liquid phase during sintering. The presence of zirconia phase in hydroxyapatite matrix played an important role in the stability of the HA phase.7 - PublicationTransport critical current density of Ag-sheathed (Tl,Cr)Sr2CaCu2O7 high temperature superconductor tapes(2001)
;A-Hamid N. ;Abd-Shukor R. ;66040771167004750914Ag-sheathed Tl-1212 tapes with a nominal composition of (Tl1.2Cr0.15)Sr2CaCu2O7 were fabricated using the powder-in-tube (PIT) method. The tapes (approximately 3-4 cm long) were annealed in oxygen flow at 820 �C, 870 �C and 890 �C each for 30 minutes, 1 hour and 5 hours, respectively. The x-ray diffraction (XRD) patterns for samples annealed at 820 �C and 870 �C showed the Tl-1212 as the dominant phase with Tl-1201 as minor phase. Scanning electron micrographs (SEM) revealed that the tapes showed no discernible favourable texture. Using a self-field approximation together with Jc dependence on temperature the characteristic length (Lc) associated with the pinning force is estimated to be approximately the same as the average grains size (Rg) for the tapes annealed at 820 �C for 30 minutes. For tapes that were annealed at 870 �C and 890 �C, Lc>Rg. The initial rapid suppression of Jc at low fields (<0.1 T) can be attributed to the weak-links phenomena as observed in other polycrystalline high-Tc materials with random grain orientations.4 - PublicationPower frequency electromagnetic fields management technologies(2001)
;Farag A. ;Said I. ;Hussain H. ;Ahmad A.S. ;57208098840 ;9336317400 ;356079228007202040740Electrical and magnetic fields are complex entities, much more than chemical agents. While exposure to chemicals can often be adequately described by the total amount ingested over some period of time, many more parameters must be considered for fields. Exposures are complicated by movement through fields, spatial variations, and other possible exposure parameters. Field management minimizes the impact that magnetic or electric fields have on their surroundings, may involve (i) measurement programs, (ii) prudent avoidance, (iii) site arrangement, (iv) design change, (v) cancellation, and (vi) shielding or a combination of these methods. This paper provides insight to several field-management strategies developed for if needed. The paper considered six distinct sources, which are transmission lines, distribution lines, substations, building wiring, appliances and transportation systems. Each source presented a unique set of limitations and possibilities for field management options. The effectiveness, cost, environmental impact, safety concerns of field management options were considered for each source.6 - PublicationModeling of various meteorological effects on contamination level for suspension type of high voltage insulators using ANN(2002)
;Ahmad A.S. ;Ghosh P.S. ;Aljunid S.A.K. ;Ahmad H. ;7202040740 ;55427760300 ;371138199007102866725The performance of polluted insulators Is very much dependent on the degree of contamination. For the high voltage Insulators to be installed In areas especially near the coast, determination of the contamination level becomes the major task to design the insulators appropriately. The aim of this paper is to obtain accurate information about the degree of contamination which the high voltage insulators are exposed to when they are installed In coastal areas. Regression technique has been used successfully in estimating the level of contamination on high voltage insulators surfaces in terms of Equivalent Salt Deposit Density (ESDD). This paper has also used artificial neural network algorithm to model ESDD as a function of various meteorological parameters. A comparative analysis has also been carried out between the two methods in this work.3 - PublicationDiscrete layer analysis of laterally loaded piles(2002)
;Lee C.Y.57193686383A discrete layer analysis of laterally loaded piles embedded in homogeneous and non-homogeneous soils is presented. The soil mass is divided into uncoupled discrete soil layers. Basically, the formulation of the analysis is similar to the subgrade reaction theory but the response of the discrete soil layers is evaluated by a semi-analytical solution, which is related to the actual soil properties and the pile geometry instead of the conventional subgrade reaction modulus. The non-linear response of the soil around the pile is represented by a simple hyperbolic soil model. The linear elastic solutions computed by the discrete layer and the more rigorous continuum approaches are compared and are found to be in satisfactory agreement. The computed non-linear response of two piles embedded in stiff clay compares favorably with field measurements.1 - PublicationUsing hot-spot-driven approach in the development of a framework for multimedia presentation on the Web(ICEIS Press, 2002)
;Al-Tahat K.S. ;Idris S.B. ;Sembok T.Mohd.T. ;Yousof M. ;6508140157 ;8230988900 ;926890040056407115700Frameworks can be seen as generative since they are intended and well suited to be used as the foundation for the development of a number of applications in the domain captured by the framework. A framework defines a high-level language with which applications within a domain are created through specialization. Specialization takes place at points of predefined refinement that are called hot spots. Hot spots are the generic and flexible aspects and parts of a framework that can be easily adapted to a specific need. Specialization is accomplished through inheritance or composition. Well-designed framework offers the domain-specification hot spots and the desired flexibility to adapt those hot spots. Hot spots are shown by hook methods and hook classes, where metapatterns express how the required flexibility, represented by the hot spots, is gained in a particular framework. We have adopted the hot-spot approach in the development of a framework for multimedia presentation on the Web. The adoption of this approach has helped us in enhancing the flexibility and extensibility of the framework. This paper describes the use of a hot-spotdriven approach in the development of a framework for multimedia presentation on the Web as well as our experience in using hot spots, design patterns, and metapatterns.4