Articles

Access the latest knowledge in applied science, electrical engineering, computer science and information technology, education, and health.

Advanced Search
Filter Icon

Filters article

Years

FAQ Arrow
Single Year
Range Year
0
0

Source Title

FAQ Arrow

Authors

FAQ Arrow

30,096 Article Results

A Front Surface Optimization Study for Photovoltaic Application

10.12928/telkomnika.v16i4.9059
A.; Universiti Teknologi Malaysia Nawabjan , F.; Universiti Teknologi Malaysia Iqbal , A. S.; Universiti Teknologi Malaysia Abdullah
In this paper, we presented a possible front surface optical enhancement of Si solar cell by optimizing the Antireflection (AR) and light trapping (LT) schemes. Conventional plasma enhanced chemical vapor deposition (PECVD) and in house hot wire chemical vapor deposition (HWCVD) tool was used to deposit Silicon Nitride (SiNX) layer and optimized at 668nm wavelength. This was followed by surface texturing of random pyramids to further enhance the broadband reflectance of the front surface. Broadband reflectance measurement using integrating sphere method showed achieved weighted average reflectance (WAR) value of as low as 1.8% and 1.5%, when 85nm SiNX was deposited on top of random pyramids structure using HWCVD and PECVD methods, respectively.
Volume: 16
Issue: 4
Page: 1383-1387
Publish at: 2018-08-01

E-Referral System Modeling Using Fuzzy Multiple-Criteria Decision Making

10.11591/ijeecs.v11.i2.pp475-486
Gandung Triyono , Sri Hartati , Reza Pulungan , Lutfan Lazuardi
Currently, the quality of health services in Indonesia is getting better. However, the referral system still has some problems. The first is the difficulty in determining the referral hospital by the condition of the patient. The second is the different parameters used to determine the referral hospitals between countries. Based on those problems, it is necessary to improve the ability of the current referral system. This study developed a reference system model for assessing the suitability of the patient's background with the referral hospital. Some of the methods used are restful on web service technologies for information exchange between primary health care doctors and referral hospitals, Fuzzy Multiple-Criteria Decision Making (FMCDM) to determine the ranking of referral hospitals that fit the patient's background. The result of this study is an intelligent system model to get the referral hospital that fit the patient's background.
Volume: 11
Issue: 2
Page: 475-486
Publish at: 2018-08-01

The Study of Stresses on Soil From Roadways Using Plaxis To Generate Potential Energy With Piezoelectric

10.11591/ijeecs.v11.i2.pp755-760
A.J.M.S. Lim , S.Y. Sim , Anting, N. , J. Prasetijo , T. I. T Noor Hasanah , H.H. Goh , Y.M.Y. Buswig , C.C. Kang
Environmental resources exploitation is one of the critical problems in environmental engineering. The overuse of environmental resources can lead to a huge impact for the environment and human itself. The problems of extracting and processing of raw materials from earth such as mining, steam power and machinery has increased year by year and this is the main reason that the resources has become very limited for the future generations to use them. This study is focused in designing a roadway through software analysis which will use the concept of piezoelectricity that will convert the stress energy from the roadways into electrical energy. A software which is called PLAXIS 2D will be used to simulate the stresses from the roadway which are caused by moving vehicle loading. The parameters of laterite and clay soil such as Specific Gravity, Liquid Limit, Friction Angle and Cohesion are obtained from the past research is needed for the input of the software. The loading application in the PLAXIS 2D uses the Mohr-Coulomb failure criterion in which fully drained and axisymmetric conditions were assumed. A non-uniform grid with 1726 elements was performed for the calculations on a 2-dimensional cross-sections of 11m x 3m roadway. The stresses resulted from the software are used to determine the value of stresses required for the piezoelectric to convert the stress energy into electrical energy.
Volume: 11
Issue: 2
Page: 755-760
Publish at: 2018-08-01

The Improvement of first Iteration Log Periodic Fractal Koch Antenna with Slot Implementation

10.11591/ijece.v8i4.pp2564-2570
N. S. M. Yaziz , M. K. A. Rahim , F. Zubir , N. S. Nadzir , R. Dewan , H. A. Majid
In this paper, a slotted is introduced at each of the radiating elements on the 1st iteration log periodic fractal Koch antenna (LPFKA). The antenna is designed to testify the appropriate performance at UHF Digital television which operates from 4.0 GHz to 1.0 GHz. The dimension of the conventional 0th iteration LPKFA is successfully reduced by 17% with the implementation of slotted. The results show a good agreement with a stable radiation pattern across the operating bandwidth, stable gain more than 5 dBi and reflection coefficient of below -10 dB over the desired frequency range.
Volume: 8
Issue: 4
Page: 2564-2570
Publish at: 2018-08-01

Algorithm for Predicting Compound Protein Interaction Using Tanimoto Similarity and Klekota-roth Fingerprint

10.12928/telkomnika.v16i4.5916
Isnan; Bogor Agricultural University Mulia , Wisnu Ananta; Bogor Agricultural University Kusuma , Farit Mochamad; Bogor Agricultural University Afendi
This research aimed to develop a method for predicting interaction between chemical compounds contained in herbs and proteins related to particular disease. The algorithm of this method is based on binary local models algorithm, with protein similarity section is omitted. Klekota-Roth fingerprint is used for the compound's representation. In the development process of the method, three similarity functions are compared: Tanimoto, Cosine, and Dice. Youden’s index is used to evaluate optimum threshold value. The result showed that Tanimoto similarity function yielded higher similarity values and higher AUC value than those of the other two functions. Moreover, the optimum threshold value obtained is 0.65. Therefore, Tanimoto similarity function and threshold value 0.65 are selected to be used on the prediction method. The average evaluation accuracy of the developed algorithm is only about 50%. The low accuracy value is allegedly caused by the only use of compound similarity on the prediction method, without including the protein similarity.
Volume: 16
Issue: 4
Page: 1785-1792
Publish at: 2018-08-01

Integrated Social Media Knowledge Capture in Medical Domain of Indonesia

10.12928/telkomnika.v16i4.8320
Kridanto; Institute of Technology Bandung Surendro , Dicky Prima; Institute of Technology Bandung Satya , Farrell; Institute of Technology Bandung Yodihartomo
The Social Media Platforms, as the one of largest part of today data traffic on the Internet, disseminate a vast volume of information, including medical information in it. Knowledge management system (KMS) approach is applied with purpose to capture, maintain, and manage tacit or explicit knowledge available and collected within the social media platforms, organization’s database, knowledge base, or document repository. By adding Indonesian Natural Language Processing (InaNLP), Machine Learning and Data Mining approach, our research has proposed a framework which is theoretically designed to improve the previous research related to social media knowledge capture model and enhance its accuracy and reliability of knowledge retrieved compared to previous knowledge capture model. This system mainly aimed for medical practitioner to give a quick suggestion of the diseases regarding to the early diagnose which has been taken in the first place. On this current research state, the pre-processing phase of the framework implementation and knowledge presentation is our main concernto maximize the information value for the knowledge users and also to reduce the language issues in texts such as ambiguity, inconsistency, use of slang vocabulary, etc.According to this research’s goal, we have designed an algorithm to extract feature from dataset.
Volume: 16
Issue: 4
Page: 1846-1856
Publish at: 2018-08-01

Maximum Power Point Tracking Charge Controller for Standalone PV System

10.12928/telkomnika.v16i4.9512
Mohd Asri; Universiti Malaysia Perlis Jusoh , Mohammad Faridun; Universiti Malaysia Perlis Naim Tajuddin , Shahrin Md; Universiti Teknologi Malaysia Ayob , Mohd Azrik; Universiti Malaysia Perlis Roslan
The depletion of conventional energy sources and global warming has raised worldwide awareness on the usage of renewable energy sources particularly solar photovoltaic (PV). Renewable energy sources are non-polluting sources which can meet energy demands without causing any environmental issues. For standalone PV systems, a low conversion efficiency of the solar panel and high installation cost due to storage elements are the two primary constraints that limit the widespread use of this system. As the size of the system increases, the demand for a highly efficient tracking and charging system is very crucial. Direct charging of battery with PV module will results in loss of capacity or premature battery degradation. Furthermore, most of the available energy generated by the PV module or array will be wasted if proper tracking technique is not employed. As a result, more PV panels need to be installed to provide the same output power capacity. This paper presents selection, design and simulation of maximum power point tracker (MPPT) and battery charge controller for standalone Photovoltaic (PV) system. Contributions are made in several aspects of the whole system, including selection of suitable converter, converter design, system simulation, and MPPT algorithm. The proposed system utilizes direct duty cycle technique thus simplifying its control structure. MPPT algorithm based on scanning approach has been applied by sweeping the duty cycle throughout the I-V curve to ensure continuous tracking of the maximum power irrespective of any environmental circumstances. For energy storage, lead acid battery is employed in this work. MATLAB/Simulink® was utilized for simulation studies. Results show that the propose strategy can track the MPPs and charge the battery effectively.
Volume: 16
Issue: 4
Page: 1413-1426
Publish at: 2018-08-01

Hypertension Drug Suitability Evaluation Based On Patient Condition with Improved Profile Matching

10.11591/ijeecs.v11.i2.pp453-461
Hari Soetanto , Sri Hartati , Retyanto Wardoyo , Samekto Wibowo
The accuracy of the type or dosage of drugs by doctors is important. The types and doses of medicines given by the doctors should match the illness suffered by the patient as well as consider the patient's health condition. In hypertension disease, the error rate of drug dosage by medical personnel is quite high, reaching 34%. Meanwhile, the administration of the type and dosage of drugs appropriate to the patient's condition required the knowledge of high medical personnel and experienced medical personnel. In this research, we developed the model of drug suitability evaluation with hypertension patient's health condition using Profile Matching method. The proposed model evaluates the patient's health condition based on the parameters provided by the expert and produces recommendations on the type of drug. To optimize the Profile Matching method, in this research we applied interpolation weighting method which calculates the proximity level of the patient profile with drug profile more accurately. Based on the experiment, the proposed model has an accuracy value of 87%, precision 87.11% and recall of 85.44%. It proves that the proposed method can provide recommendations on the right type of hypertension medication. Also, the interpolation weighting method is proven to increase the accuracy. 
Volume: 11
Issue: 2
Page: 453-461
Publish at: 2018-08-01

Development of Leaf Area Meter Using Open CV for Smartphone Application

10.12928/telkomnika.v16i4.8608
Tony K.; Universitas Muhammadiyah Yogyakarta Hariadi , Zulfan; Universitas Muhammadiyah Yogyakarta Fadholi , Anna NN; Universitas Muhammadiyah Yogyakarta Chamim , Nafi A; Universitas Muhammadiyah Yogyakarta Utama , Indira; Universitas Muhammadiyah Yogyakarta Prabasari , Slamet; Universitas Muhammadiyah Yogyakarta Riyadi
This study aimed to design an accurate and practical system of leaf area determination using a smartphone. A software application for leaf area computation was developed using Open CV (Open Source Computer Vision) library. Open CV software was tested to estimate the accuracy of leaf area calculation. Leaf area calculations were undertaken using three different image resolutions to compare their accuracy. The results of the software calculations were then compared with the results of the laboratory leaf area meter to identify any errors. The results showed that higher image resolutions improved accuracy by reducing errors. High resolution image gave higher accuracy, however processing speed decreased. Leaf measurement in this project resulted in accuracy range between 92.8% to 99.0%. It was concluded that the Open CV algorithm gave fast and adequate accuracy for leaf area calculation, and that the smartphone mobile application system was practical for field use.
Volume: 16
Issue: 4
Page: 1857-1863
Publish at: 2018-08-01

Switchable Wideband Metamaterial Absorber and AMC reflector for X-band Applications and Operations

10.12928/telkomnika.v16i4.9065
M. M.; Universiti Teknologi Malaysia Gajibo , M. K. A.; Universiti Teknologi Malaysia Rahim , N. A.; Universiti Teknologi Malaysia Murad , O.; Universiti Teknologi Malaysia Ayop , H. A.; Universiti Tun Hussein Onn Malaysia Majid
A single layered metamaterial structure with capabilities of switching from a wideband metamaterial absorber to an AMC reflector and vice versa is presented in this paper. A flame retardant 4 substrate with physical thickness of 1.60mm was used. The absorption rate, reflection rate, reflection phase and surface current distribution were studied and discussed. The operational incidental wave angles were varied from 0o to 65o. A peak reflection of about 90% was achieved at 11.20 GHz with a usable bandwidth (-90 to +90) of 3.01 GHz by the AMC reflector. The metamaterial absorber demonstrated a wideband performance (from 8.10 GHz to 14.30 GHz). It achieved 100% absorption at 11.20 GHz and not less than 65
Volume: 16
Issue: 4
Page: 1535-1541
Publish at: 2018-08-01

Identifying Citronella Plants From UAV Imagery Using Support Vector Machine

10.12928/telkomnika.v16i4.7450
Candra; Brawijaya University Dewi , Achmad; Brawijaya University Basuki
High-resolution imagery taken from Unmanned Aerial Vehicle (UAV) is now often used as an alternative in monitoring the agronomic plants compared to satellite imagery. This paper presents a method to identify Citronella among other plants based on UAV imagery. The method utilizes Support Vector Machine (SVM) to classify Citronella among other plants according to the extraction of texture feature. The implementation of the method was evaluated using two group of datasets: 1) consists of Citronella, Kaffir Lime, other green plants, vacant soil, and buildings, and 2) consists of Citronella and paddy rice plants. The evaluation results show that the proposed method can identify Citronella on the first group of datasets with an accuracy 94.23% and Kappa value 88.48%, whereas on the second group of datasets with an accuracy 100% and Kappa value 100%.
Volume: 16
Issue: 4
Page: 1877-1885
Publish at: 2018-08-01

Determining Best Window Size for an Improved Gabor Transform in EMG Signal Analysis

10.12928/telkomnika.v16i4.9049
E.F.; Universiti Putra Malaysia (UPM) Shair , S.A.; Universiti Putra Malaysia (UPM) Ahmad , A.R.; Universiti Teknikal Malaysia Melaka (UTeM) Abdullah , M.H.; Universiti Putra Malaysia (UPM) Marhaban , S.B. Mohd; Universiti Putra Malaysia (UPM) Tamrin
Electromyography EMG is a standout amongst the most regularly utilized tools to study human muscle condition. But due to the intricate attributes of the EMG itself, time-frequency distributions such as Gabor transform and spectrogram are more preferred than the simpler time distribution and frequency distribution. These techniques have been broadly utilized as it can provide both time and frequency information. However, both techniques have a fix window size for all frequency values, thus there exist a problem of determination of the window size, where excessively limit window and too wide window, will result in poor frequency resolution and time resolution, respectively. Along these lines, the point of this study is to choose the best window size so as to be utilized with Gabor transform to screen human muscle activity during core-lifting task. Four electrodes were placed on the right and left biceps brachii, and left and right erector spinae. In this study, the results of five acceptable window sizes (300, 400, 430, 450 and 520) were shown, despite the fact that other window sizes were also tested. Three criteria have been considered during the determination of the best window size, which are good time resolution, good frequency resolution, and high accuracy. Results demonstrate that window size of 450 is the best compared to others. As an additional analysis, the result is compared to a spectrogram and it can be seen that Gabor transform is better, as it has the flexibility in choosing the window size, thus affects the resolution and accuracy.
Volume: 16
Issue: 4
Page: 1650-1658
Publish at: 2018-08-01

Evaluation of Color Models for Palm Oil Fresh Fruit Bunch Ripeness Classification

10.11591/ijeecs.v11.i2.pp549-557
Nurbaity Sabri , Zaidah Ibrahim , Dino Isa
This paper investigates the application of eight color models for automatic palm oil Fresh Fruit Bunch (FFB) ripeness classification with multi-class Support Vector Machine (SVM).  Ripeness classification is important during harvesting to ensure that they are harvested during the correct ripe stage for optimum oil production.  Since color is a significant indicator for agriculturists to determine the ripeness of FFB, it is critical to determine the right color model. Eight color models have been investigated namely, HSV, I1I2I3, LAB, XYZ, YCbCr, YIQ, YUV and RGB. Color moments were extracted from each of these color models for the classification of four stages of FFB ripeness that are unripe, under-ripe, ripe and over-ripe.  A database of five hundred images of palm oil FFB has been constructed and experiments showed that YCbCr and YUV outperform the other color models.
Volume: 11
Issue: 2
Page: 549-557
Publish at: 2018-08-01

Distributed Control System Applied in Temperatur Control by Coordinating Multi-loop Controllers

10.12928/telkomnika.v16i4.3135
Edi; Bandung State Polytechnic Rakhman , Feriyonika; Bandung State Polytechnic Feriyonika
In Distributed Control System (DCS), multitasking management has been important issues continuously researched and developed. In this paper, DCS was applied in global temperature control system by coordinating three Local Control Units (LCUs). To design LCU’s controller parameters, both analytical and experimental method were employed. In analytical method, the plants were firstly identified to get their transfer functions which were then used to derive control parameters based on desired response qualities. The experimental method (Ziegler-Nichols) was also applied due to practicable reason in real industrial plant (less mathematical analysis). To manage set-points distributed to all LCUs, master controller was subsequently designed based on zone of both error and set-point of global temperature controller. Confirmation experiments showed that when using control parameters from analytical method, the global temperature response could successfully follow the distributed set-points with 0% overshoot, 193.92 second rise time, and 266.88 second settling time. While using control parameters from experimental method, it could also follow the distributed set-points with presence of overshoot (16.9%), but has less rise time and settling time (111.36 and 138.72 second). In this research, the overshoot could be successfully decreased from 16.9 to 9.39 % by changing master control rule. This proposed method can be potentially applied in real industrial plant due to its simplicity in master control algorithm and presence of PID controller which has been generally included in today industrial equipments.
Volume: 16
Issue: 4
Page: 1568-1576
Publish at: 2018-08-01

Measurement of Shear Strain in Map Liquefaction Area for Earthquake Mitigation in Bengkulu City

10.12928/telkomnika.v16i4.8043
Muhammad; Bengkulu University Farid , Arif Ismul; Bengkulu University Hadi
Bengkulu city is well-known as a high-risk area for an earthquake. One of the effects of the earthquake is liquefaction, the phenomenon in which the strength and stiffness of the soil are reduced by shock. The researchers measured the quantity of liquefaction by knowing the value of Vs30 values that can be obtained from the United States Geological Survey (USGS). In this study, however, we measured liquefaction based on the shear strain value (γ). Here, the shear strain values could be determined by measuring the seismic vulnerability index and the peak ground acceleration. The vulnerability index was obtained by measuring the resonance of the frequency and the amplification factor using a short period seismometer with 3 components (2 horizontal components and 1 vertical component), whereas the peak ground accelerationα was obtained from the earthquake data that happened in Bengkulu City in 2000. The result showed that Vs30 and shear strain negatively correlated.
Volume: 16
Issue: 4
Page: 1597-1606
Publish at: 2018-08-01
1 2 3
...
2006 2007
Show 1435 of 2007

Discover Our Library

Embark on a journey through our expansive collection of articles and let curiosity lead your path to innovation.

Explore Now
Library 3D Ilustration