996 research outputs found

    Disaster Management in Malaysia: An Application Framework of Integrated Routing Application for Emergency Response Management System

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    Malaysia has experienced various disasters either natural or manmade disaster. One of the critical phases in Disaster Management System life cycle is response phase. In this phase, connectivity analysis such as a navigation service to help emergency rescue (ER) units reach at disaster area on time is necessary. Nowadays, commercial navigation system seems not appropriate to be used by ER units as they have different preferences. In addition, location information that is vital was not fully utilized in disaster management, especially in doing multi-task analysis. Thus, the real potential of GIS technology in managing spatial data including real-time (moving objects) data of ER units may influence the quality of the service. However, the services should be supported by a good data model. In order to eliminate inappropriate information, incomplete data, and overloaded information from Database Management System (DBMS) sent to the user, this paper will present the framework of integrated routing application for emergency response units embedded with context-aware

    Requirements Negotiation: Does Consensus Reduce Software Development Cost?

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    The requirements engineering activities within a software project are known to be critical to the successful production of a correctly functioning system. This is particularly so when considering the varying views of multiple stakeholders. One promising approach for improving the outcome is to introduce formal negotiation. Negotiation is beneficial to identify and to resolve conflicts between stakeholders. Consensus achieved through negotiation represents all key stakeholders’ perspectives and perceptions regarding the system to be developed. The aim of implementing negotiation is to minimize the possibility of introducing defects during the creation of requirements and to decrease later effort required to fix requirements’ defects. This paper answers the question of whether consensus gives positive significant impact to the software project as a whole or not. It presents an approach to estimate the savings from implementing negotiation in the requirements elicitation process. An empirical evaluation study is adopted through a role play experiment to evaluate the benefit of exercising negotiation. The net gain and the return on investment show positive values which suggest that negotiation activities are worth an investment. Based on a return on investment of 197 percent on average, this paper suggests that negotiation is a useful prevention activity to inhibit defects from occurring during the requirements creation process

    A Low-Loss Coaxial Cavity Microwave Bandpass Filter with Post-Manufacturing Tuning Capabilities

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    This paper presents a low-loss coaxial cavity microwave bandpass filter with post-manufacturing tuning capabilities. A systematic filter development using a low-pass prototype as the starting point to produce a fourth-degree Chebyshev bandpass response is demonstrated. The coaxial cavity filter based on the transverse electromagnetic mode of the propagation has a center frequency of 2.5 GHz and a bandwidth of 160 MHz. An insertion loss (S21) of 0.15 dB and a return loss (S11) better than 15 dB are obtained, particularly in the passband. An excellent agreement between ideal circuit, EM simulation and measurement results has been achieved. The filter is then modified to have two channels, known as a diplexer, wherein center frequencies are at 2.5 GHz and 2.9 GHz at a bandwidth of 200 MHz. This type of microwave filter will be useful in any microwave system wherein low insertion loss and high selectivity are crucial, such as in base station, radar, and satellite transceivers

    Understanding media literacy in relation to adolescent soft drink consumption behavior

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    This paper examines relationship between media literacy and the Theory of Planned Behavior (TPB) variables focusing on consumption of soft drink among adolescents in Klang Valley, Malaysia. In addition, this paper also determines soft drink consumption, level of media literacy and the influences of the TPB variables on the intention of soft drink consumption. A cluster sampling method was used in collecting data within the Klang Valley area. The sample consisted of 436 adolescents from secondary school, aged between 13 to 18 years old. Two main scales utilized were Media Literacy (ML) scale and TPB scale. The descriptive, multiple linear regression and Pearson product-moment correlation analyses were carried out to answer the research objectives. Results revealed that 36% of respondents drank a minimum of 1 can, bottle or glass of soft drink for the past seven days and possess good level of media literacy (35%).Meanwhile, 14% of variance in adolescents’ intention of soft drink consumption is explained by TPB variables. Additionally, the total media literacy score towards soft drink advertisement was significantly positively correlated with attitude (r = 0.250, p<.05) and subjective norms (r = 0.174, p<.05). Conversely, total media literacy was significant negatively correlated with intention to consume soft drink (r = -0.19, p<.05) and indicated that media literacy could lower the intention to consume soft drink, thus can reduce soft drink consumption among adolescents. The importance of this study is to help the authorities, soft drink marketers and producers in Malaysia to better understand media literacy and adolescent soft drink consumption behavior

    A Numerical Algorithm for Solving Stiff Ordinary Differential Equations

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    An advanced method using block backward differentiation formula (BBDF) is introduced with efficient strategy in choosing the step size and order of the method. Variable step and variable order block backward differentiation formula (VSVO-BBDF) approach is applied throughout the numerical computation.The stability regions of the VSVO-BBDFmethod are investigated and presented in distinct graphs.The improved performances in terms of accuracy and computation time are presented in the numerical results with different sets of test problems. Comparisons are made between the proposed method and MATLAB’s suite of ordinary differential equations (ODEs) solvers, namely, ode15s and ode23s

    Peripheral interface controller-based maximum power point tracking algorithm for photovoltaic DC to DC boost controller

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    A method of developing a maximum power point tracking (MPPT) algorithm for photovoltaic (PV) utilizing a peripheral interface controller (PIC) is presented in this paper. The efficiency and adequacy of a PV depend on the temperature and the exposed position to the sun. Thus, there is an optimum point at which the operating power is at maximum. The goal is to operate the PV module at this point (MPP). It can be accomplished by using the MPPT algorithm designed with a DC-DC boost converter. The boost converter, MPPT circuit, PIC18F4550 microcontroller and PV panel are the main components used in this design. The current and voltage produced by the solar panel are observed continuously by a closed-loop control system. The microcontroller-based control system adjusts the duty cycle of the converter to extract the maximum power. With a DC input voltage of 15 V, the boost converter is capable of generating an output voltage of an approximately 60 Vdc at a maximum power of 213.42 W with minimum voltage ripple as compared to 84 W without the MPPT. It proved the effectiveness of the developed algorithm

    Optimization of Modified Sliding Mode Controller for an Electro-hydraulic Actuator System with Mismatched Disturbance

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    This paper presents the design of the modified sliding mode controller (MSMC) for the purpose of tracking the nonlinear system with mismatched disturbance. Provided that the performance of the designed controller depends on the value of control parameters, gravitational search algorithm (GSA), and particle swarm optimization (PSO) techniques are used to optimize these parameters in order to achieve a predefined system’s performance. In respect of system’s performance, it is evaluated based on the tracking error present between reference inputs transferred to the system and the system output. This is followed by verification of the efficiency of the designed controller in simulation environment under various values, with and without the inclusion of external disturbance. It can be seen from the simulation results that the MSMC with PSO exhibits a better performance in comparison to the performance of the similar controller with GSA in terms of output response and tracking error

    A study of geo-polymer as alternative material in automotive brake pad

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    Todays, there are various of alternative materials that have been studied by many researchers in order to find the appropriate combination of brake pad manufacturing in the automotive industry. Some of the alternative materials that has being used including palm slag, banana peels, nutshell and others. This provide more economical benefit and also environmental preservation by utilizing the waste of natural fiber. In this study, geo-polymer brake pad has been prepare using the waste product which is barren soil. Barren soil is chosen as an alternative brake pad material candidate from natural resources as it consists of deserts, dry salt flats, beaches, sand dunes, exposed rock, strip mines, quaries, and gravel pits. This barren soil are mixed with another candidates such as binder, reinforcement, abrasives and lubricant following the standard formulation of brake pad manufacturing. In this works, three type of samples have been used. The elemental composition for sample 1, 2 and 3 are main content with 10%, 5%, 15% alumina and 10%, 15%, 5% graphite respectively. The physical properties of geo-polymer brake pads studied including hardness test and its morphology structure. Sample has been characterized based on two main parameters which are hardness test and morphology analysis. From the analysis, it was found that a prototype from sample 3 exhibit the highest hardness index compare to sample 1 and 2. Sample 3 hardness also much better compare to the conventional brake pad with 64% of the hardness increment. This finding also support by the morphological analysis, whereby the surface of sample 3 show a compact and flat surface with less cracking and porosity. From both parameter, it can be concluded that sample 3 has a great potential to become a suitable geo-polymer brake pad. Here, the composition of a combination alumina and graphite in all sample play as important role in enhance the hardness parameter for the potential brake pad prototype

    Development of a Quadruped Crawling Robot Prototype

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    Although wheeled robots are commonly used, it has limited ability to move to any terrains at ease. They suffer from difficulties when travelling over uneven and rough terrains. Legged robots have an advantage over the wheeled robots in that they are suited for such situations. The implementation of legged robots normally requires many motors to move every joint in a robot leg. Additional motor will increase the construction cost, robot weight, and the demand for power supply. Moreover, robot simulation becomes more complex. This research is related to the design and development of a cost effective quadruped autonomous robot. The robot can moves according to a unique pattern using three servo motors as its actuator in each of its leg. The design of the robot is firstly made with CAD program and then the structure of the body and the leg is analyzed in order to find a correct balance and to make sure the servo motors are capable to move the robot. A prototype of the quadruped robot is fabricated and tested thoroughly. Experimental studies are carried out to test its stability issues when the robot moves. The robot is capable of moving forward, backward, turn left and turn right by crawling its way. A microcontroller is used as the brain of the robot assisted by two analog distance sensor for better obstacle sensing. It uses a rechargeable battery as the power supply for the microcontroller. The servo motors on the other hand are powered by another rechargeable battery. At the end of this research, a working prototype has been developed

    Design High Gain PHEMT LNA for Wireless Application at 5.8 GHz

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    This research present a design of a higher gain (68.94dB) for PHEMT LNA using an inductive drain feedback technique for wireless application at 5.8GHz. The amplifier it is implemented using PHEMT FHX76LP transistor devices. The designed circuit is simulated with Ansoft Designer SV. The LNA was designed using inductive drain feedback, inductive generation to the source, and the T-network as a matching technique was used at the input and output terminal. The low noise amplifier (LNA) provides a noise figure 0.64 dB and gain (S21) of 68.94 dB. The output reflection (S22), input reflection (s11) and return loss (s12) are -17.37 dB, -15.77 dB and -88.39 dB respectively. The measurement shows the stability were at 4.54 and 3-dB bandwidth of 1.72 GHz. The input sensitivity is -92 dBm exceeded the standards required by IEEE 802.16
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