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25,002 Article Results

An Ant Colony-based Heuristic Algorithm for Joint Scheduling of Post-earthquake Road Repair and Relief Distribution

10.12928/telkomnika.v13i2.1437
Bei; Shanghai Jiao Tong University Xu , Yuanbin; Shanghai Jiao Tong University Song
Emergency road repair and distribution of relief goods are crucial for post-earthquake response. However, interrelationships between those two tasks are not adequately considered in their work schedules, especially in cases with very limited repair resources, leading to unnecessary delay and expenditure. A time-space network model is constructed to better describe the constraints arising from the interrelationships in joint scheduling of road repair and relief distribution works. An ant colony-based heuristic algorithm is developed to solve the NP-hard model efficiently for practical use, followed by a case study of Wenchuan earthquake to validate the planning tool and to demonstrate its feasibility for resolving real world problem.
Volume: 13
Issue: 2
Page: 632-643
Publish at: 2015-06-01

Basal Study on Power Control Strategy for Fuel Cell/Battery Hybrid Vehicle

10.12928/telkomnika.v13i2.987
Dingyue; Chang’an University Chen , Xia; Jiaotong University Li , Lihao; Strasbourg University Chen , Yonghui; Chang’an University Zhang , Li; Chang’an University Yang , Songsong; Chang’an University Li
In order to enhance the fuel economy of hybrid vehicle and increase the mileage of continuation of journey, the power control strategy (PCS) is as significant as component sizing in achieving optimal fuel economy of the fuel cell/battery hybrid vehicle (FCBHV). The models of FCBHV structure and optimal power control strategy are developed by electric vehicle simulation software ADVISOR which uses a hybrid backward/forward approach. The results demonstrate that the proposed control strategy can satisfy the power requirement for two standard driving cycles and achieve the power distribution among various power sources. The comprehensive comparisons with the power tracking controller (PTC) which is wide adopted in ADVISOR verify that the proposed control strategy has better rationality and validity in terms of fuel economy and dynamic property in two standard driving cycles. Therefore, the proposed strategy will provide a novel approach for the advanced power control system of FCBHV.
Volume: 13
Issue: 2
Page: 421-431
Publish at: 2015-06-01

Optimization of Power System Scheduling Based on Shuffled Complex Evolution Metropolis Algorithm

10.12928/telkomnika.v13i2.1472
Zi-Yang; Hohai University Qiang , Feng-Ping; Hohai University Wu , Jia-Rui; Hohai University Dong , Rui-Dong; University of Bath Heng
Due to the world’s increasingly serious energy crisis, shortage of resources, and environmental degradation, traditional power system analysis and scheduling optimization methods have faced new challenges. This article examines the features of optimal scheduling of power system containing cascade hydropower, and establishes a scheduling model based on the Shuffled Complex Evolution Metropolis (SCEM-UA) algorithm. This model takes the cost of power generation, emission of gaseous pollutants, and the characteristics of the generators fully into account. Constraints on the changes in thermoelectric generator power output were added to the set of constraint conditions, reducing the impact of thermal power fluctuations on the power system. Here, the SCEM-UA algorithm was used to solve the problem of optimal power system scheduling and render the model capable of global optimization searches. Analyses of simulated cases have demonstrated that the SCEM-UA algorithm can resolve the conflict between convergence speed and global search capability, increasing the global search capability of the model.
Volume: 13
Issue: 2
Page: 413-420
Publish at: 2015-06-01

Comparative Study of a Three Phase Cascaded H-Bridge Multilevel Inverter for Harmonic Reduction

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/1500
Rosli Omar , Mohammed Rasheed , Marizan Sulaiman , M. R Tamijis
The aim of this research project is to analyze and design of energy storages in electrical distribution system. In this paper presents a comparative study between sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) technique, based on generate signal five level of cascaded H-bridge for reduction harmonics in the multilevel inverter output. A multilevel inverter is a preferred choice for most medium-voltage and high-power applications, as well as cascaded H-bridge (CHB) five-level inverters due to its advantages such as low cost, light weight and compact size. It is suitable particularly for use in a cascaded H-bridge multilevel inverter due to reduced total harmonic distortion (THD). Harmonic content in three phase multilevel inverter can be investigated by generating (SPWM) and (SVPWM) algorithm signal based on a five-level (CHB). The proposed system is designed using MATLAB/SIMULINK consists of cascaded H-bridge (CHB) multilevel inverter. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.7949
Volume: 14
Issue: 3
Page: 481-492
Publish at: 2015-06-01

Object Detector on Coastal Surveillance Radar Using Two-Dimensional Order-Statistic Constant-False Alarm Rate Algoritm

10.12928/telkomnika.v13i2.1189
Dayat; Indonesian Institute of Science Kurniawan , Purwoko; Indonesian Institute of Science Adhi , Arif; Indonesian Institute of Science Suryadi , Iqbal; Indonesian Institute of Science Syamsu , Teguh; Indonesian Institute of Science Praludi
This paper describes the development of radar object detection using two dimensional constant false alarm rate (2D-CFAR). Objective of this development is to minimize noise detection if compared with the previous algorithm that uses one dimensional constant false alarm rate (1D-CFAR) algorithm such as order-statistic (OS) CFAR, cell-averaging (CA) CFAR, AND logic (AND) CFAR and variability index (VI) CFAR where has been implemented on coastal surveillance radar. The optimum detection result in coastal surveillance radar testing when Pfa set to 1e-2, Kth set to 3/4*Nwindow and Guard Cell set to 0. Principle of 2D-CFAR algorithm is combining of two CFAR algorithms for each array data of azimuth and range. Order statistic (OS) CFAR algoritm is implemented on this 2D-CFAR by fusion rule of AND logic.The algorithm of 2D-CFAR is developed using Microsoft Visual C++ 2008 and the output of 2D-CFAR is plotted on PPI scope radar using GDI+ library. The result of 2D-CFAR development shows that 2D-CFAR can minimize noise detected if compared with 1D-CFAR with the same parameter of CFAR. Best performance of 2D-CFAR in object detection when Nwindow set to 128. The time of software processing of 2D-CFAR is about two times longer than the 1D-CFAR.
Volume: 13
Issue: 2
Page: 624-631
Publish at: 2015-06-01

Battery State-of-Charge Estimation with Extended Kalman-Filter using Third-Order Thevenin Model

10.12928/telkomnika.v13i2.1467
Low Wen; Universiti Teknologi Malaysia Yao , Wirun A/l; Universiti Teknologi Malaysia Prayun , Mohd Junaidi Bin; Universiti Teknologi Malaysia Abdul Aziz , Tole; Universitas Ahmad Dahlan Sutikno
Lithium-ion battery has become the mainstream energy storage element of the electric vehicle. One of the challenges in electric vehicle development is the state-of-charge estimation of battery. Accurate estimation of state-of-charge is vital to indicate the remaining capacity of the battery and it will eventually maximize the battery performance and ensures the safe operation of the battery. This paper studied on the application of extended Kalman-filter and third order Thevenin equivalent circuit model in state-of-charge estimation of lithium ferro phosphate battery. Random test and pulse discharge test are conducted to obtain the accurate battery model. The simulation and experimental results are compared to validate the proposed state-of-charge estimation method.
Volume: 13
Issue: 2
Page: 401-412
Publish at: 2015-06-01

Business Process Reengineering on Customer Service and Procurement Units in Clinical Laboratory

10.12928/telkomnika.v13i2.509
Dewi; Gunadarma University Agushinta R. , Anindito Yoga; Gunadarma University Pratama , Suryadi; Gunadarma University Harmanto S
Existing business processes on a Clinical laboratory located in Bekasi is still run manually. It takes a lot of time to do more process, especially in customer service and procurement units. These inefficient processes are analyzed here. Utilization of information technology (IT) supports operations of company and even improves efficiency and effectiveness of a company. However, the use of information technology must be balanced with readiness of existing resources to operate. Without supporting resources, especially human resources available, information technology is nothing. Business Reengineering Process method used to comprehend the existing business process, determine processes to be reengineered, investigate alternative redesign, simulate the existing business processes and the proposed business processes, performed an analysis of simulation results, and seeking opportunities in corporate using information technology.This Business Process Reengineering (BPR) research helped Clinical laboratory especially in customer service and procurement in improving efficiency and effectiveness of existing processes that will ultimately reduce cost and time. Results showed that business processes increase with information technology utilization and minimize the use of employee.
Volume: 13
Issue: 2
Page: 644-653
Publish at: 2015-06-01

International Telecommunication Union-Radiocommunication Sector (ITU-R) P.837-6 and P.837-7 performance to estimate Indonesian rainfall

10.12928/telkomnika.v13i2.1431
Yonghua; South China University of Technology Wang , Pin; Guangdong University of Technology Wan , Qin; Guangdong University of Technology Deng , Yuli; South China University of Technology Fu
The cognitive radio technology can improve the efficiency of spectrum utilization byproviding dynamic spectrum access to unoccupied frequency bands. Spectrum sensing is one of the key technologies of cognitive radio networks. The spectrum sensing performance of cognitive radio networks will be greatly reduced in the low SNR environment, especially when using energy detection. Because the stochastic resonance system can improve the energy detection system output SNR .To improve the spectrum sensing performance of cognitive radio networks in the low SNR environment, the stochastic resonance of the single-mode nonlinear optical system is applied to spectrum sensing based on the energy detection method in this paper. The simulation results show that in the low SNR environment, the energy detection based on stochastic resonance of the single-mode nonlinear optical system has better performance than traditional energy detection.
Volume: 13
Issue: 2
Page: 494-501
Publish at: 2015-06-01

Robust Control of Bench-top Helicopter Using Quantitative Feedback Theory

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/1502
Ameerul Hakeem Mohd Hairon , Hasmah Mansor , Teddy Surya Gunawan , Sheroz Khan
A three degree of freedom (3-DOF) bench-top helicopter is a simplified aerial vehicle which is used to study the behaviors of the helicopter as well as testing multiple flight control approaches for their efficiency. Designing helicopter’s dynamic control is a challenging task due to the presence of high uncertainties and non-linear behavior. In this study, Quantitative Feedback Theory (QFT) is proposed to achieve robust control over the helicopter model. It utilizes frequency domain methodology which ensures plant’s stability by considering the feedback of the system and thus removing the effect of disturbances and reducing sensitivity of parameter’s variation. The proposed technique is tested against LQR-tuned PID controller to demonstrate its procedures as well as its performance. Simulation results obtained through MATLAB Simulink software shown us that QFT algorithm managed to reduce percentage of overshoot and settling time about 50% and 30% respectively over the classical PID controller. DOI: http://dx.doi.org/10.11591/telkomnika.v14i3.7899
Volume: 14
Issue: 3
Page: 500-507
Publish at: 2015-06-01

Experimental Validation of a Multi Model PI Controller for a Non Linear Hybrid System in LabVIEW

10.12928/telkomnika.v13i2.1322
M.Kalyan; VIT University Chakravarthi , Nithya; VIT University Venkatesan
In this paper a real time Single Spherical Tank Liquid Level System (SSTLLS) has been chosen for investigation. This paper describes the design and development of a Multi Model PI Controller (MMPIC) using classical controller tuning techniques for a single spherical nonlinear tank system. System identification of these different regions of nonlinear process are done using black box modeling, which is identified to be nonlinear and approximated to be a First Order Plus Dead Time (FOPDT) model. A proportional and integral controller is designed using LabVIEW and Chen-Hrones-Reswick (CHR), Zhuang-Atherton (ZA), and Skogestad’s Internal Model Controller (SIMC) tuning methods are implemented in real time. The paper provides the details about the data acquisition unit, shows the implementation of the controller, and comparision of the results of PI tuning methods used for an MMPI Controller.
Volume: 13
Issue: 2
Page: 547-555
Publish at: 2015-06-01

Integration of Signal and Artificial Noise in MIMO Wiretap Channel

10.12928/telkomnika.v13i2.995
Zhiliang; Beijing Institute of Technology Yang , Aihua; Beijing Institute of Technology Wang , Xiqiang; North University of China Taiyuan Qu
In this paper, the integrated signal-to-artificial noise (ISAN) design is applied in MIMO wiretap channel to ensure wireless communication security. When the information of eavesdropper is unknown, the total power is divided into two parts: signal and artificial noise. The signal can secure certain quality at the legitimate receiver. The artificial noise which is in the null space of the receiver channel matrix can deteriorate eavesdropper channel by the method of beam forming. The artificial noise power is distributed evenly in other space, so that the eavesdropper channel is deteriorated in all directions. The signal to interface and noise ratio (SINR) is regarded as the efficient parameter on measuring reliability and security of information at the legitimate receiver. The simulations reveal that ISAN can deteriorate the eavesdropper channel and safeguard the information transmission on the premise of the given SINR of the legitimate receiver.
Volume: 13
Issue: 2
Page: 478-486
Publish at: 2015-06-01

Negative Impact of Abattoir Activities and Management in Residential Neighbourhoods in Kuala Terengganu, Malaysia

10.11591/ijphs.v4i2.4722
Auwalu Abdullahi , Norizhar Kadarman , Azmi Hassan , Ibrahim Sulaiman Madobi
Poor management of abattoirs results in air and water pollution especially resident’s in their close proximity. The objevtive of the study was to investigate the effect of poor management of abattoirs on the quality of life and health of residents in their vicinity. A cross sectional survey was conducted within two month period. Fifty six residents of buildings located approximately five kilometers radius to the abattoir were randomly selected for interview using questionnaire. Among the 56 residents interviewed, 20 (35.7%) were sicked. Almost half (33.9%) of the residents suspected the sickness to be related to abattoir hazards. The prevalence of diseases and symptoms experianced by the residents were typhoid fever (14.4%), Diarhoea (12.5%), Coughing (10.7%), Asthma (8.9%), Foot and Mouth Disease (7.1%) and Dengue (3.6%). The main associated factors of abattoir activities on residents ‘s health were contamination of air with pollutants (odds ratio,15.52; 95% confidence interval, 3.62-10.52), water contamination (11.44; 3.17, 12.28), gutters and drainages blockage (6.35; 1.26, 9.99) and prevention of children from outdoor activities (4.65; 1.33, 16.31). There was also reported case of food poisoning among the residents. Abattoir activities has direct and indirect negative effect on residents health who are in close proximity.
Volume: 4
Issue: 2
Page: 124-130
Publish at: 2015-06-01

Voltage Regulation in a Microgid with Hybrid PV/Wind Energy

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/1491
Joseph Olawole Petinrin , Mohamed Shaaban , J.O. Agbolade
Autonomous operation of a microgrid system hinges on the efficient combination of various energy resources to maintain self-sustainability of energy supply. Furthermore, it is equally important to coordinate the resources to regulate the microgrid voltage profile. The problem becomes more complicated if these resources have intermittent characteristics such as solar PV and wind turbines. The potential for using energy storage promise to have a major impact on schemes for voltage control in a microgrid. A hybrid Particle Swarm Optimization/Gravitational Search Algorithm (PSOGSA) based approach is used in this paper to contemplate the optimum size and location of energy storage to reduce voltage variations and feeder losses caused by PV/wind energy integrated in a microgrid. Effectiveness of the proposed method is implemented through a quasi-static time sequence analysis over a 24-hourly simulation period on autonomous Microgrid system. The corresponding voltage profile is analyzed under different operating conditions, with high penetration level of PV/wind energy. Test results show that the energy storage causes reduction in system losses and enhances system capability to maintain voltages within the permissible limits. DOI:  http://dx.doi.org/10.11591/telkomnika.v14i3.7905 
Volume: 14
Issue: 3
Page: 402-409
Publish at: 2015-06-01

Risk Factors of Low Vision in Children

10.11591/ijphs.v4i2.4720
Tiur Dianawati , Liena Sofiana
Low vision and blindness is a vision disorder that becomes an important issue with regard to a person's independence. According to data owned by the World Health Organization in 2011, the number of blind people in the world reached 39 million, 246 million for low vision and 285 million for blindness. The purpose of this study was to know the incidence of risk factors in children with low vision in Low Vision Service Center Pertuni Yogyakarta, Indonesia. This study was an observational analytic study employed cross sectional design. The subject participated in this study was 139 children. Data were analyzed using correlation analysis. The instrument used was check list. There were relationships between the sex with low vision (p = 0.028, RR = 1.308), there was no relationship between regular eye checkup with low vision incidence (p = 0.801, RR = 1.054). There was relationship between the use of vision aids with low vision (p = 0.000, RR = 0.640), there was a relationship between the cataract with low vision (p = 0.000, RR = 1.472), there was a correlation between the refractive disorderwith low vision (p = 0.000, RR = 0.625).There should be an awareness of health behaviours in the use of vision aids as needed and balanced diet with sufficient physical activity and regular.
Volume: 4
Issue: 2
Page: 113-118
Publish at: 2015-06-01

TLC-Bioautography Profile of Ethyl Acetate Extract of 5 Bacteria Isolated from Ficus carica L Rhizosphere

10.11591/ijphs.v4i2.4716
Nanik Sulistyani , Iin Narwanti
Research has been conducted on the 5 isolates of bacteria isolated from the rhizosphere of Ficus carica L as a producer of antibiotics. The previous study showed they have NRPS gene profiles that differ from each other. This study aims to determine the TLC Rf spots having inhibition activity against the growth of Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. The study was conducted using the 5 bacteria isolates, namely T19, T24, T25, T37 and T41. All isolates were fermented at room temperature for 14 days. Further the each broth culture was filtered and extracted using ethyl acetate. Components in the extract were separated by thin layer chromatography (TLC) with the mobile phase of chloroformmethanol (7: 3), followed by bioautography test against the S. aureus and E. coli to determine the chromatogram spots containing antibiotics. TLC results showed all isolates had different chromatogram profiles. The bioautography results showed that only isolate T25 can produce antibiotics against S. aureus. The antibiotic spot was at Rf 0.9 in the use of chloroform-methanol (7: 3) solvent system.
Volume: 4
Issue: 2
Page: 81-87
Publish at: 2015-06-01
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