Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
Not a member yet
776 research outputs found
Sort by
Reliable characterization of organic dielectrics degraded by high electric field
Get PDFThe study of the degradation of organic dielectrics is of great interest for industrial applications, especially in electrical industry. So great, that other applications are also being developed in the fields of optical communications, information storage, stacked memories or manufacturing new components in micro technology, mainly in the fields of MEMS and sensors. Under the same conditions of temperature and of high intensity electric field during operation, we present results on Poly Ethylene Terephthalate (PET) which is the most useful material; the degradation considered here is induced by high electric field in ambient atmosphere with a high voltage range scaled around on 12kV during 1h.The physical and thermal characterization is carried out by an implementation of an experimental technique very fine high sensitivity and high accuracy measures such as Broadband Dielectric Spectroscopy (BDS) and Differential Scanning Calorimetry (DSC). Phase transition, relaxation mode changes, molecular relaxation and trapping effect will be discussed
Spatial Variability Study of Duty Cycle in GSM 900 and 1800 MHz Bands in Rural and Urban Environments
Get PDFThis paper examines the spatial variability of duty cycle in the GSM 900 and 1800 MHz bands within Kwara State, Nigeria. The results show spatial variance in the duty cycle with average occupancies of 1.67%, 17.76%, 10.55% and 0.39%, 11.00% and 5.11 in the rural, urban and all locations for 900 and 1800 MHz bands. Findings also show that there is very high positive correlation between rural 900/1800 MHz and urban 900/1800 MHz. But very high negative correlations exits between urban 900 and rural 1800, and urban 1800 and rural 1800. There is a weak and negative correlation between rural and urban 900 MHz, rural-urban 1800. These results clearly showthe abundance of unutilised spectrum within the GSM bands. Therefore, regulatory commissions should adopt flexible spectrum reuse strategy to relax the regulatory bottlenecks to maximize the scarce radio resources in the licensed bands, especially for rural network deployment
Comparison of Transient Stability Response for MMPS using UPFC with PI and Fuzzy Logic Controller
Get PDFThe increasing pressure on the power system increases the complexity that is becoming a concern for the stability of the power system and mainly for transitory stability. To operate the system in the event of faults, Flexible AC Transmission System (FACTS) devices are used that provide opportunities to control power and vibrations damping. This paper deals with the two control strategies of the Unified Power Flow Controller (UPFC) to damping the system oscillations stability. The stability of the Multi-Machine Power System (MMPS) was analysed with the presence of UPFC. The first strategy is the traditional PI controller (PI-C) with UPFC, and the second strategy is the proposed Fuzzy Logic controller (FL-C) proposed for UPFC device along with PI controller. The MATLAB R2014a was used in all simulations. Based on the results, FL-C for UPFC device along with the PI controller has proven its superiority by has enhanced response to the system, thus minimized in the transitions overshoot and undershoot, and has lower ripple compared to traditional PI-C, both with and without UPFC
The methods of duo output neural network ensemble for prediction of coronary heart disease
Get PDFThe occurrence of Coronary heart disease (CHD) is hard to predict yet, but the assessment of CHD risk for the next ten years is possible. The prediction of coronary heart disease can be modelled using multi-layer perceptron neural network (MLP-ANN). Prediction model with MLP-ANN has either positive or negative CHD output, which is a binary classification. A prediction model with binary classification requires determination of threshold value before the classification process which increases the uncertainty in the classification process. Another weakness of the MLP-ANN model is the presence of overfitting. This study proposes a prediction model for coronary heart disease using the duo output artificial neural network ensemble (DOANNE) method to overcome the problems of overfitting and uncertainty of classification in MLP-ANN. This research method was divided into several stages, namely data acquisition, pre-processing, modelling into DOANNE, neural network ensemble training with Levenberg-Marquard (LM) algorithm, system performance testing, and evaluation. The results of the study showed that the use of DOANNE-LM method was able to provide a significant improvement from the MLP-ANN method, indicated by the results of statistical tests with p-value <0.05
Structural adaptive anisotropic recursive filter for blind medical image deconvolution
Get PDFPerformance of radiographic diagnosis and therapeutic intervention heavily depends on the quality of acquired images. Over decades, a range of pre-processing for image enhancement has been explored. Among the most recent proposals is iterative blinded image deconvolution, which aims to identify the inheritant point spread function, degrading images during acquisition. Thus far, the technique has been known for its poor convergence and stability and was recently superseded by non-negativity and support constraints recursive image filtering. However, the latter requires a priori on intrinsic properties of imaging sensor, e.g., distribution, noise floor and field of view. Most importantly, since homogeneity assumption was implied by deconvolution, recovered degrading function was global, disregarding fidelity of underlying objects. This paper proposes a modified recursive filtering with similar non-negativity constraints, but also taking into account local anisotropic structure of content. The experiment reported herein demonstrates its superior convergence property, while also preserving crucial image feature
Integration of time of use (TOU) tariff in net energy metering (NEM) scheme for electricity customers
Get PDFThe introduction of Net Energy Metering (NEM) scheme for electricity customers in Malaysia is seen as an improvement from the previous Feed-In Tariff (FIT). However, the new NEM scheme only benefited the large residential customers but not to medium and small residential customers. Due to electricity tariff blocks structure, the large customers can avoid paying expensive tariff and hence reducing their electricity bill. This is not the case for medium and small customers since they are already paying lower tariff blocks due to their lower electricity consumption. This issue will discourage most residential customers to install solar PV system in their home and affect the Malaysia’s renewable energy target. This paper proposed a NEM scheme that integrates Time of Use (TOU) electricity tariff to the scheme. The proposed NEM-TOU scheme will be simulated, tested and compared to the new NEM scheme by using practical small, medium and large residential customers’ data. The results show that the proposed TOU-NEM scheme able to overcome the weakness of the current scheme where all customers (large, medium and low) can benefited by installing solar PV system in their home
Network anomaly detection research: a survey
Get PDFData analysis to identifying attacks/anomalies is a crucial task in anomaly detection and network anomaly detection itself is an important issue in network security. Researchers have developed methods and algorithms for the improvement of the anomaly detection system. At the same time, survey papers on anomaly detection researches are available. Nevertheless, this paper attempts to analyze futher and to provide alternative taxonomy on anomaly detection researches focusing on methods, types of anomalies, data repositories, outlier identity and the most used data type. In addition, this paper summarizes information on application network categories of the existing studies
Modeling and simulation of a wirelessly-powered thermopneumatic micropump for drug delivery applications
Get PDFThis paper presents modeling and finite element analysis of a thermopneumatic micropump with a novel design that does not affect the temperature of the working fluid. The micropump is operated by activating a passive wireless heater using wireless power transfer when the magnetic field is tuned to match the resonant frequency of the heater. The heater is responsible for heating an air-heating chamber that is connected to a loading reservoir through a microdiffuser element. The solution inside the reservoir is pumped through a microchannel that ends with an outlet hole. The thermal and pumping performances of the micropump are analyzed using finite element method over a low range of Reynold’s number ⩽ 10 that is suitable for various biomedical applications. The results demonstrate promising performance with a maximum flow rate of ∼2.86 μL/min at a chamber temperature of 42.5 ºC, and a maximum pumping pressure of 406.5 Pa. The results show that the developed device can be potentially implemented in various biomedical areas, such as implantable drug delivery applications
State of charge estimation based on adaptive algorithm for Lead-Acid battery
Get PDFThe usage of batteries in recent years has become widespread in many fields e.g. in electric vehicles, energy renewable and stand-alone systems which require a robust approach for estimation of the state of charge (SOC). The SOC represents an important factor to guaranty safe operations. A lot of methods have been used to predict the state of charge. The coulomb counting method is the famous and widely used among them, but have limitation due to its accuracy. Another used approach is the Kalman Filter, which improves the estimation efficiency, to reach a good performance in SOC prediction. The version of adaptive extended Kalman filter (AEKF) technique is applied in this paper. This paper presents an experimental performance of technique of Kalman filter, for solving the problem of accurate SOC. The method is used to compute the terminal voltage in such a way to estimate the SOC. The proposed algorithm is based on preselected Thevenin model after the identification of its parameters. It has been used to predict the SOC based on nonlinear equations, and evaluation of the approach is verified with the experimental results. The final results signify that the estimation matched with the proposed model and the algorithm is performed optimally, thus the maximum soc estimation error is the fines
Multiband hairpin-line bandpass filters by using metamaterial complimentary split ring resonator
Get PDFTelecommunication systems for the new generation have greatly stimulated the demand for multi-band bandpass filters with compact dimensions, low insertion loss, robust, low cost and less complex design. In this paper, a compact multi-band bandpass filter, with the fractional bandwidth of 40% and 20% at resonant frequency 3.5 and 5.5 GHz respectively with the response of Chebyshev passband ripple of 0.1 dB is presented. This bandpass filter is suitable for WiMAX application. The design is based on the hairpin-line configuration and metamaterial of complementary split ring resonator structure. The hairpin-line is used for the compact structure design and easy to fabricate because it has open-circuited ends that require no grounding. While the complementary split ring resonator structure is easy to design and can provide multi-band without affecting of size and performance of the filter. The simulated results show the dual-band bandpass response with the insertion loss is 0 dB and high attenuation at stopband. The proposed filter provides a compact, low insertion loss, and less complex structure design that are promising candidates in order to meet the demands of the new generation of communication systems