Optimal solar powered system for long houses in Sarawak by using homer tool

Ensuring electricity coverage for rural areas in Malaysia is still a big challenge due to the houses are in deep forest and scattered locations. The estimated coverage in 2015 is only 94% and still depending on conventional fossil-fuel generators. Considering full utilization of renewable source is highly recommended. Therefore, this paper proposes optimal design of full solar powered system for long houses in one selected area in Sarawak, Malaysia. Interestingly, the work has been started with evaluation and estimation of loads with site survey done to the selected area, which is Kampung Sungai Merah. The site visit has been conducted to survey and estimate the loads at the site. The design considers meteorological and climate data, specifications of system, and simulation configuration. HOMER tool is used in this work which comes with the optimization algorithm to search for the least cost system. The simulation results reveal the outcomes by considering three discount rates of 3%, 6% and 12%, and the system is presented with the best design for each rate. Lower discount rate contributes to higher PV and lower battery architectures as compared to higher discount rates. In short, it can be concluded that the system is optimally designed to be fully depended on utilization of solar as solid renewable source, which affects PV and battery architectures as two key design elements. Finally, this work should be able to provide the designer an opportunity to fully consider various options in developing the best renewable and full solar powered system for rural electrification

Development and Application of Outdoor Router Cost Estimation with Parametric Modelling Technique

Internet development is a challenging issue among Internet Server Providers (ISPs) and researchers due to high investment cost and unforeseen risk. The internet accessibilities of those rural areas are low and seem disconnected from the society. Rural areas unable to enjoy the benefits from high-speed Internet. Rural internet development is not prioritized because of low population density and return of investment from urban area development is more favorable. Outdoor equipment such as router, antennas and access points are the main components in Internet development. The accuracy of various cost estimation model is depending on the availability of raw data and data analysis techniques. There is no accurate model that allow ISPs to estimate the cost of outdoor routers for Wireless Fidelity (Wi-Fi) transmission. Those estimations can assist ISPs in risk management and reduce the total project cost. Therefore, this paper aimed to produce and demonstrate a suitable outdoor router cost estimation model. Friis transmission equation and link budget equation were used in this model. Suitable key parameters were selected by using P-value regression analysis. Original key parameters and calculated unique key parameters were utilized in this model to provide better performance and realistic estimated cost. This paper also demonstrated the usage of outdoor router cost estimation model under long-range and short-range wireless data transmission

Cost estimation methods for internet infrastructure deployment in Rural Sarawak: a review

In rural Sarawak, the internet accessibility is low due to unreliable power grids to support telecommunication network and large geographical area. The risk for network infrastructure implementation is high for internet service provider (ISP), thus more practical and accurate cost estimation methods should be used. This paper reviews different types of cost estimation methods and the accuracy and feasibility of each methods are discussed and compared for network infrastructure implementation in rural Sarawak. The unique characteristics of rural Sarawak are considered in this work, including the topography, development of rural areas and acceptance of new technologies. Different cost estimation methods are identified for different senarios and availability of data

Enhancing MEMS switch reliability through the reduction of dielectric charging and bouncing mitigation

RF MEMS switch is becoming the preferred choice for RF switching due to its outstanding performance when compared to conventional counterparts. However, due to its electro-mechanical nature, the RF MEMS switch suffers from reliability issues such as early failure, inconsistent switching characteristics, and higher cost where a driver circuit is necessary to drive the MEMS device. Thus, the reliability and characteristic of the RF MEMS switch have to be improved significantly before it can benefit from a much wider market acceptance. Dielectric charging in MEMS switches was reported to be one of the causes that limits the lifespan of the device. This phenomenon is mainly due to the high actuation voltage required to activate the MEMS switch where a penetration and trapping of charge carriers occur within the dielectric layer present in most capacitive RF MEMS switches. Other notable causes of early failure of the MEMS switch are mechanical failure and material degradation of the contacting surfaces. Mechanical contact made in metal-tometal MEMS switches improves the insertion loss, however, accelerates the physical failure of the device. Contact bouncing occurrence during the actuation period was reported to be one of the main factors that accelerates wear and tear of the contacting surfaces. In this work, the dielectric charging was investigated for the conventional driving method and existing charge-reducing actuation schemes through numerical simulation and corroborated by experimental findings. A novel actuation voltage waveform was proposed to effectively minimize the charge accumulation during continuous actuation, thus prolonging the lifetime of the MEMS switches. Also, the contact bouncing occurrence of MEMS switch was analyzed by simulating the dynamic response of the moving component upon contact. The ability of mitigating contact bouncing of the proposed actuation voltage waveform was evaluated and compared to the existing actuation schemes. Experiments were conducted on commercially available RF MEMS switches to support the analytical findings. Apart from life-limiting issues, MEMS switches also suffer from inconsistency of switching response due to parameters variation. The micro-scaled fabrication imperfection causes the devices' parameters to vary which in turn affects the switching characteristics of the MEMS switch such as pull-in and pull-out voltage requirements. In order to examine the robustness of different actuation waveforms to the MEMS switch's parameters variation, the dynamic response of the typical RF MEMS switch was simulated with changeable parameters, and the effects on the switching response were observed. Experiments were carried out to verify the analytical findings. Beside the characteristic variation due to fabrication, the temperature effect on MEMS switches was also investigated. A novel actuation strategy was introduced to optimize the actuation voltage while the MEMS switch is working under varying temperature condition. Finally, a generic MEMS switch driver was developed to implement the proposed actuation voltage waveform. As demonstrated in the analyses, the reliability of electrostatically actuated MEMS switch is expected to improve significantly without any physical changes on the MEMS device by replacing the conventional actuation method with the proposed MEMS switch driver. In addition, the implementation of the proposed Temperature Dependent Actuation Voltage (TDAV) approach was also presented. This actuation method can also be integrated into the proposed MEMS switch driver as an add-on feature when the system is operating under changeable temperature condition

Accurate indoor positioning technique using RSSI assisted inertial measurement

An indoor positioning technique based on the inertial measurement of the object and the received signal strength indicator (RSSI) measured from an active RFID tag placed on the object is presented. The inertial measurement complements the inaccuracy of the RSSI measurements, especially when the object is far away from RFID reader. Correspondingly, a strong RSSI reading when the object is near a RFID reader provides accurate information about the location of the object. This information could then be used to amend the position estimated from the inertial measurement. Experiment has shown that the proposed technique provides better positioning accuracy

Accurate indoor positioning technique using RSSI assisted inertial measurement

Abstract An indoor positioning technique based on the inertial measurement of the object and the received signal strength indicator (RSSI) measured from an active RFID tag placed on the object is presented. The inertial measurement complements the inaccuracy of the RSSI measurements, especially when the object is far away from RFID reader. Correspondingly, a strong RSSI reading when the object is near a RFID reader provides accurate information about the location of the object. This information could then be used to amend the position estimated from the inertial measurement. Experiment has shown that the proposed technique provides better positioning accuracy