Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
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An Extended Tropospheric Scintillation Model for Free Space Optical Communication Systems
Get PDFFluctuations caused mostly by tropospheric scintillation at the free space optical receiver end have been a major problem in the rapid development of telecommunication and the increasing demands for larger bandwidth is forcing the use of free space optical (FSO) technology. This paper examined existing tropospheric scintillation models of Karasawa, Van de Kamp model, Otung, Ortgies and ITU-R, and discovered that all of them operate at the microwave range, which limits their application in FSO laser beam technology that operates in PHz frequency-range. ITU-R model was later selected owing to its global application and modified for use in FSO communication system. The new model can serve as basis for communication engineers to use as platform in the link budgetary for planning and design of low margin systems of free space optical communication link
Optimal solutions for fixed head short-term hydrothermal system scheduling problem
Get PDFIn this paper, optimal short-term hydrothermal operation (STHTO) problem is determined by a proposed high-performance particle swarm optimization (HPPSO). Control variables of the problem are regarded as an optimal solution including reservoir volumes of hydropower plants (HdPs) and power generation of thermal power plants (ThPs) with respect to scheduled time periods. This problem focuses on reduction of electric power generation cost (EPGC) of ThPs and exact satisfactory of all constraints of HdPs, ThPs and power system. The proposed method is compared to earlier methods and other implemented methods such as particle swarm optimization (PSO), constriction factor (CF) and inertia weight factor (IWF)-based PSO (FCIW-PSO), two time-varying acceleration coefficient (TTVACs)-based PSO (TVAC-PSO), salp swarm algorithm (SSA), and Harris hawk algorithm (HHA). By comparing EPGC from 100 trial runs, speed of search and simulation time, the suggested HPPSO method sees it is more robust than other ones. Thus, HPPSO is recommended for applying to the considered and other problems in power systems
Deep Learning-aided Brain Tumor Detection: An Initial Experience based Cloud Framework
Get PDFLately, the uncertainty of diagnosing diseases increased and spread due to the huge intertwined and ambiguity of symptoms, that leads to overwhelming and hindering the reliability of the diagnosis process. Since tumor detection from MRI scans depends mainly on the specialist experience, misdetection will result an inaccurate curing that might cause critical harm consequent results. In this paper, detection service for brain tumors is introduced as an aiding function for both patients and specialist. The paper focuses on automatic MRI brain tumor detection under a cloud based framework for multi-medical diagnosed services. The proposed CNN-aided deep architecture contains two phases: the features extraction phase followed by a detection phase. The contour detection and binary segmentation were applied to extract the region of interest and reduce the unnecessary information before injecting the data into the model for training. The brain tumor data was obtained from Kaggle datasets, it contains 2062 cases, 1083 tumorous and 979 non-tumorous after preprocessing and augmentation phases. The training and validation phases have been done using different images’ sizes varied between (16, 16) to (128,128). The experimental results show 97.3% for detection accuracy, 96.9% for Sensitivity, and 96.1% specificity. Moreover, using small filters with such type of images ensures better and faster performance with more deep learning.
Towards energy transition: conjoint assessment of large-scale PV system performance and interconnection impacts in isolated microgrid
Get PDFEnvironmental, energy security and electricity demand concerns stimulate solar-grid integration. However, intermittent, non-dispatchable PV characteristics may challenge passive grid operation. This paper contains the comprehensive planning and assessment of a 2 MWp CdTe-based PV system deployment proposed for hybrid operation in an isolated 11 kV 10-bus microgrid in Brunei. The presented approach combinedly assesses PV system performance and scenario-based interconnection impacts based on a detailed PV system model considering deployment conditions. Various interconnection points with multiple sets of feeder-specific measured load profiles are examined. Results show the PV system designed for maximum annual generation achieves performance ratio of 90.6%. While time-series power flow assessment reveals grid operation enhancement, there are concerns at times of generation-demand mismatch requiring proper genset sequencing and reactive power management. Meanwhile, faster relay operating time and reverse fault current are demonstrated in existing protection scheme. Dynamic grid stabilities are preserved in various generation intermittency and loss events, including the most challenging condition of further inertia and spinning reserve reduction reaching a frequency of 96.02%. Finally, optimal interconnection point fulfilling multi-objectives on losses, voltage profile and line reserve capacity is identified. The findings indicate a good prospect of the synergy for advancing energy transition. The analysis could facilitate RE planning and policymaking
A Unique Way to Generate Password at Random Basis and Sending it Using a New Steganography Technique
Get PDFData hiding is a technique for secure transmission of confidential data. Many data hiding techniques exist and steganography is the most important one. This paper presents a new steganography method in spatial domain. We use steganography to send confidential information from sender to receiver. Here, we generate password at random basis in a unique way based on system time and date. Then we send this confidential password using steganography by implementing a totally new embedding and extraction technique based on exact length of bits in binary representation of ASCII values. Here, confidential text information is embedded into cover image generating a stego image and sent to receiver maintaining top level secrecy
Engineering Practices of Determining Transmission Capacity and Delay of Interconnecting Line Taking into Account its Configuration and Cost
Get PDFThis article contains information on engineering practice of determining transmission capacity of computer network line. The article presents a variant of engineering synthesis of computer network, which is a combined process of mathematical and heuristic methods combining. The engineering synthesis is offered as vector and global, because it must result in network development, optimal in terms of its practical use. All the significant network quality indicators, including economic and practical, are taken into consideration. In case of engineering synthesis, it is not possible that only one quality indicator is significant: there are always at least two significant indicators – a cost and an indicator that characterizes the main effect that is achieved in case of network use (efficacy). If at least one of the quality indicators significant for practical use is not taken into account, such network cannot be considered optimal. Computer network synthesis usually consists of structure synthesis, parameters optimization and discrete network selection. If network topology is maintained unchanged, it is possible to formulate an optimization task for line transmission capacity. The solution of transmission capacity task, which is constantly changing, may be chosen as a starting point for the selection of discrete indicator of transmission capacity
Application of High-Voltage Discharges for Disinfecting Water
Get PDFA three-factor experiment is conducted on the disinfection of water by treatment with high-voltage discharges formed to achieve an electro-hydraulic effect, in order to detect optimal conditions and rules for the course of the processes under study. In the study, a high-voltage installation with an electro-hydraulic spark gap, an EnSURE luminometer (Hygiena) for measuring the level of hygiene of water and its solutions, test tubes for determining the total number of ATP in AquaSnap Total brand water (AQ100X) are used as materials and equipment. The influence of design parameters and exposure modes of an electro-hydraulic installation on the properties of water as a result of the generation of high-voltage discharges is investigated; experimental data are revealed for measuring the level of microbiological contamination of the water sample, which, according to the analysis of the data obtained, is reduced, which can serve as the basis for the possibility of the potential use of the effects of high-voltage discharges as a method of preparing water under irrigation in greenhouses; optimal ratios of factors for disinfecting a pond water sample from a source of artificial origin are revealed: operating voltage 19.9 kV, capacitance 0.1445 μF and the number of discharges 2861 pieces
A Robust Tool for Monitoring and Synchronizing Smart Grid through Adaptive Comb Filter
Get PDFThe power system signals are often polluted with harmonics and noise as a result of nonlinear load. This non stationary signal has to be monitored carefuly before it propagates as a grid problem.This article describes the design of adaptive comb filter, extraction of amplitude, frequency and phase with respect to time for monitoring purpose and extraction of harmonic components for suppressing the contamination present in the signal for synchronization with smart grid. The adaptive comb filter algorithm is a synchronizing tool implemented in Matlab/Simulink environment.The response of the filter is compared with enhanced phased locked loop to describe the characteristics of adaptive comb filter.The algorithm tracks the transient (dynamic) and steady state behaviour of the signal effectively, efficiently and accurately
Assessment of Different Strategies in Optimizing Network Operation Incorporating PV System
Get PDFRenewable distributed generation is increasingly deployed in distribution networks for meeting the rapidly-growing electricity demand and energy transition target. Its optimal integration could maximize the benefits in network operation and eliminate technical challenges to passive networks associated with its non-dispatchable generation characteristic. In this paper, various scenarios based on three different optimization strategies viz. i) distributed installation, ii) power factor and iii) network configuration are assessed. The optimization goals are minimizing active line losses and improving network voltage profile within the constraints. The analysis considers PV system integration, and the base configuration of centralized PV system installation is taken as the reference for comparison. Time-series load flow algorithm utilizing average PV system generation and load demand profiles is adopted in solving the multi-objective optimization problem with index weighting factors. A real 11 kV distribution network in Brunei is modeled as the test system and integrated with the scenario-based PV system. The variations in generation and demand are considered in the work. The findings present the opportunities in furthering network operation enhancement with the distributed installation strategy having the highest potential. The analysis provides a clear optimization potential of each scenario, which shall be beneficial to the utility in planning new deployment
Automated Detection of Retinal Hemorrhage based on Supervised Classifiers
Get PDFSupervised machine learning algorithm based retinal hemorrhage detection and classification is presented. For developing an automated diabetic retinopathy screening system, efficient detection of retinal hemorrhage is important. Splat, which is a high level entity in image segmentation is used to mark out hemorrhage in the pre-processed fundus image. Here, color images of retina are portioned into different segments (splats) covereing the whole image. With the help of splat level and GLCM features extracted from the splats, three classifiers are trained and tested using the relevant features. The ground-truth is established with the help of a retinal expert and using dataset and clinical images the validation was done. The output obtained using the three classifiers had more than 96 % sensitivity and accuracy