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Makara Journal of Technology
Published by Universitas Indonesia
ISSN : 23552786     EISSN : 23564539     DOI : https://doi.org/10.7454/mjt
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Engineering Materials Science & Nanotechnology Mechanical Engineering
MAKARA Journal of Technology is a peer-reviewed multidisciplinary journal committed to the advancement of scholarly knowledge and research findings of the several branches of Engineering and Technology. The Journal publishes new results, original articles, reviews, and research notes whose content and approach are of interest to a wide range of scholars. It also offers rapid dissemination. MAKARA Journal of Technology covers the recent research in several branches of engineering and technology include Electrical & Electronics Engineering, Computer Engineering, Mechanical Engineering, Chemical & Bioprocess Engineering, Material & Metallurgical Engineering, Industrial Engineering, Civil & Architecture Engineering, and Marine Engineering. Criteria used in determining acceptability of contributions include newsworthiness to a substantial part of the engineering & technology and the effect of rapid publication on the research of others. This journal, published three times each year, is where readers look for the advancement of discoveries in engineering and technology.
Arjuna Subject : Teknik (semua kategori) - Teknik (Lain-Lain)
Articles 485 Documents
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Discrete Power Control in Heterogenous Networks Wang, Yuanyuan; Hardjawana, Wibowo; Vucetic, Branka
Makara Journal of Technology Vol. 20, No. 1
Publisher : UI Scholars Hub

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Abstract

In heterogeneous networks (HetNets) where femtocell base stations (FBSs) are deployed within the radio coverage of macrocell base stations (MBSs) to increase network capacity, co-channel interference limits overall system performance with universal frequency reuse. This paper investigates new distributed downlink discrete power control scheme for FBSs in HetNets with FBSs cooperation. The objective of the proposed power control scheme is to maximize the number of simultaneous FBSs transmissions in a single transmission wireless channel where each FBS is allowed to transmit only if the signal-to-interference-noise ratio (SINR) requirements for both FBSs and MBS users are satisfied. We apply a stochastic learning automata technique to FBSs where each FBS is treated as a learning automaton and maintains a probability vector to select its discrete transmit power. During the learning process, each FBS adjusts its probability vector based on the feedback from FGW that indicates the number of FBSs transmissions that can be supported under the SINR requirement constraints of FUEs and MUEs. Simulation results show the proposed algorithm can achieve more than twice the number of simultaneous FBS transmissions achieved by existing schemes in the literature.
Analysis of Arm Movement Prediction by Using the Electroencephalography Signal Darmakusuma, Reza; Prihatmanto, Ary Setijadi; Indrayanto, Adi; Mengko, Tati Latifah; Andarini, Lidwina Ayu; Idrus, Achmad Furqon
Makara Journal of Technology Vol. 20, No. 1
Publisher : UI Scholars Hub

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Abstract

Various technological approaches have been developed in order to help those people who are unfortunate enough to be afflicted with different types of paralysis which limit them in performing their daily life activities independently. One of the proposed technologies is the Brain-Computer Interface (BCI). The BCI system uses electroencephalography (EEG) which is generated by the subject’s mental activity as input, and converts it into commands. Some previous experiments have shown the capability of the BCI system to predict the movement intention before the actual movement is onset. Thus research has predicted the movement by discriminating between data in the “rest” condition, where there is no movement intention, with “pre-movement” condition, where movement intention is detected before actual movement occurs. This experiment, however, was done to analyze the system for which machine learning was applied to data obtained in a continuous time interval, between 3 seconds before the movement was detected until 1 second after the actual movement was onset. This experiment shows that the system can discriminate the “pre-movement” condition and “rest” condition by using the EEG signal in 7-30 Hz where the Mu and Beta rhythm can be discovered with an average True Positive Rate (TPR) value of 0.64 ± 0.11 and an average False Positive Rate (FPR) of 0.17 ± 0.08. This experiment also shows that by using EEG signals obtained nearing the movement onset, the system has higher TPR or a detection rate in predicting the movement intention.
Texture Analysis using The Neutron Diffraction Method on The Non Standardized Austenitic Steel Process by Machining,Annealing, and Rolling Priyanto, Tri Hardi; Parikin, Parikin; Li, Meijuan
Makara Journal of Technology Vol. 20, No. 1
Publisher : UI Scholars Hub

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Abstract

Austenitic steel is one type of stainless steel which is widely used in the industry. Many studies on austenitic stainless steel have been performed to determine the physical properties using various types of equipment and methods. In this study, the neutron diffraction method is used to characterize the materials which have been made from minerals extracted from the mines in Indonesia. The materials consist of a granular ferro-scrap, nickel, ferro-chrome, ferro-manganese, and ferro-silicon added with a little titanium. Characterization of the materials was carried out in three processes, namely: machining, annealing, and rolling. Experimental results obtained from the machining process generally produces a texture in the 〈100〉 direction. From the machining to annealing process, the texture index decreases from 3.0164 to 2.434. Texture strength in the machining process (BA2N sample) is 8.13 mrd and it then decreases to 6.99 in the annealing process (A2DO sample). In the annealing process the three-component texture appears, cube-on-edge type texture {110}〈001〉, cube-type texture {001}〈100〉, and brass-type {110}〈112〉. The texture is very strong leading to the direction of orientation {100}〈001〉, while the {011}〈100〉 is weaker than that of the {001}, and texture with orientation {110}〈112〉 is weak. In the annealing process stress release occurred, and this was shown by more randomly pole compared to stress release by the machining process. In the rolling process a brass-type texture{110}〈112〉 with a spread towards the goss-type texture {110}〈001〉 appeared, and the brass component is markedly reinforced compared to the undeformed state (before rolling). Moreover, the presence of an additional {110} component was observed at the center of the (110) pole figure. The pole density of three components increases with the increasing degree of thickness reduction. By increasing degrees of rolling from 81% to 87%, the value of orientation distribution function increases by a factor about three times.
A Comparison of American, Norwegian, and Russian Standards in Calculating the Wall Thickness of Submarine Gas Pipeline Dianita, Cindy; Dmitrieva, Tatyana Vladimirovna
Makara Journal of Technology Vol. 20, No. 1
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Abstract

One of the key issues in the pipeline design is wall thickness calculation. This paper highlights a comparison of wall thickness calculation methods of submarine gas pipeline based on Norwegian Standard (DNV-OS-F101), Indonesian Standard SNI 3474 which refers to American Standard (ASME B31.8), and Russian Standard (VN39-1.9-005-98). A calculation of wall thickness for a submarine gas pipeline in Indonesia (pressure 12 MPa, external diameter 668 mm) gives the results of 18.2 mm (VN39-1.9-005-98), 16 mm (ASME B31.8), and 13.5 mm (DNV-OS-F101).The design formula of hoop stress due to internal pressure is interpreted in different ways for every standard. Only Norwegian Standard requires calculating hoop stresses in the inner surface, which leads to a decreased value of the wall thickness. Furthermore, the calculation of collapse factor due to external pressure is only regulated in American and Norwegian Standards while Russian Standard uses that factor as an intermediate parameter in calculating local buckling. For propagation buckling, either Russian or American Standard explains empirical formula of critical hydrostatics pressure as the input in propagation buckling calculation. This formula is almost similar to the empirical formula of Norwegian Standard. From the comparison of these standards, DNV OS-F101 gives more stringent requirements than others.
Optimization of Electricity Generation Schemes in the Java-Bali Grid System with Co2 Reduction Consideration Farizal, Farizal; Septia, Wenty Eka; Rachman, Amar; Nasruddin, Nasruddin; Mahlia, Teuku Meurah Indra
Makara Journal of Technology Vol. 20, No. 2
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Abstract

This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas). The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN) has to generate up to 30% of electricity from renewable energy (RE), and the cost of electricity (COE) is expected to increase to 617.77 IDR per kWh for a fuel balancing option, while for fuel switching option, PLN has to generate 29% of electricity from RE, and the COE is expected to increase to 535.85 IDR per kWh.
The Knowledge-Based Analysis on Medium Resolution Images of Remote Sensing to Extraction Information Land use Type SCS-CN, the Case Study on Grompol Watershed Raharjo, Puguh Dwi; Gunawan, Totok; Hadi, Mohammad Pramono
Makara Journal of Technology Vol. 20, No. 2
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Abstract

Remote sensing imagery Landsat-8 is one image that has a good temporal resolution; in addition to the availability of data, this image can be obtained free of charge. Land cover type SCS-CN is part of a unit of land that affects runoff. The use of medium resolution imagery in reducing the SCS-CN land use type is considered relatively difficult, and it yields less good accuracy. Limitations on multispectral classification only rely on facts derived from spectral reflection, so that the two data are the same since different characteristic results are not so good. This study aims to determine the accuracy of precision medium-resolution imagery in reducing parameter land use type SCS-CN by using the knowledge-based analysis. The importance of understanding the landscape-ecology can be used to assist the translation from land cover in the form of land use. Vegetation factors and ecosystems are often used to generate metrics-based landscape. Accuracy from the interpretation of remote sensing image medium-resolution is obtained by 85.17%. Therefore, Landsat-8, in addition to easy retrieval of data, can also be used to identify the type of land cover SCS-CN, which is useful for the interests of surface water resources.
Study on Oil Palm Fresh Fruit Bunch Bruise in Harvesting and Transportation to Quality Krisdiarto, Andreas Wahyu; Sutiarso, Lilik
Makara Journal of Technology Vol. 20, No. 2
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Abstract

There are losses of production due to oil palm field’s material handling. Activities that may raise the losses are harvesting and transportation, which may cause bruise and damage to fruit. This research was aimed to learn the bruise of fresh fruit bunch (FFB) phenomenon in harvesting and transportation. Method used in this research was measuring the bruise area resulted by FFB falling when harvested, loading (throwing up) FFB to truck bin, and transporting using truck. These data, coupled with weight of bruised fruit, were calculated to get FFB bruise index. Each FFB bruise index is related to potential free fatty acid (FFA) value. FFA is one of important quality indicator of crude palm oil. The harvesting was conducted at mineral land and peat land, and the loading and transportation was conducted using wooden board truck and dump (iron board) truck. There was a difference between bruise index and FFA of FFB fall on mineral and on peat land. FFA of mineral land harvesting was 2.19% while of peat land was 1.27%. It was obvious that fruit quality degradation was higher when FFB positioned at the bottom of bin truck layer rather than at the top. FFA of truck bin bottom layer was 2.79% while of top layer was 0.64%. It was found that there was a cumulative bruise on FFB within material handling, start from harvesting, loading up to truck bin, and transporting from field to loading ramp.
Sugarcane Bagasse as a Carrier for the Immobilization of Saccharomyces cerevisiaein Bioethanol Production Anita, Sita Heris; Mangunwardoyo, Wibowo; Yopi, Yopi
Makara Journal of Technology Vol. 20, No. 2
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Sugarcane bagasse was used as a carrier to immobilize Saccharomyces cerevisiae in bioethanol production. This research aims to study the potential use of sugarcane bagasse as an alternative carrier for cell immobilization and improvement in the production process of cell immobilization in bagasse. The results showed that the physical characteristics of sugarcane bagasse as a carrier were water content (7.77 ± 0.35%), water retention (4.80 ± 0.44 g/g), water absorption index (8.58 ± 0.22 g/g), and lignin content (24.40 ± 1.52 %). Determination of cell retention was performed in an inoculum volume of 50 mL yeast suspension with various carrier weights (2.5, 5, 10, and 20 g). The highest cell retention was obtained in ratio of 2.5 g carrier/50 mL cell suspension with cell retention of 5.41 ± 1.06 mg/g, or known as biocatalyst. Biocatalyst, as much as 1.5, 3, 4.5, and 6 g, were used as inoculum for a 24 hour bioethanol fermentation. The best concentration and productivity of bioethanol, obtained by using 3 g of biocatalyst, were 23.95 ± 0.28 g/L and 1.24 ± 0.01 g/L/hours. The average of bioethanol yield for a 24 hour fermentation by using immobilized cells was three times higher than the free cells system.
Automatic Arrhythmia Beat Detection: Algorithm, System, and Implementation Jatmiko, Wisnu; Setiawan, I Md. Agus; Akbar, Muhammad Ali; Suryana, Muhammad Eka; Wardhana, Yulistiyan; Rachmadi, Muhammad Febrian
Makara Journal of Technology Vol. 20, No. 2
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Cardiac disease is one of the major causes of death in the world. Early diagnose of the symptoms depends on abnormality on heart beat pattern, known as Arrhythmia. A novel fuzzy neuro generalized learning vector quantization for automatic Arrhythmia heart beat classification is proposed. The algorithm is an extension from the GLVQ algorithm that employs a fuzzy logic concept as the discriminant function in order to develop a robust algorithm and improve the classification performance. The algorithm is tested against MIT-BIH arrhythmia database to measure the performance. Based on the experiment result, FN-GLVQ is able to increase the accuracy of GLVQ by a soft margin. As we intend to build a device with automated Arrhythmia detection, FN-GLVQ is then implemented into Field Gate Programmable Array to prototype the system into a real device.
The Effect of Irradiation of Fe and Ar Ion on the Surface Morphology of Diamond Thin Film Related to the Magnetoresistance Property Mustofa, Salim; Purwanto, Setyo; Mishima, Kenji
Makara Journal of Technology Vol. 20, No. 2
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The irradiation of Fe and Ar ion was applied on the surface of diamond/Si thin film to know its effect on the morphology of thin film.The magnetoresistance property was also studied. Ion irradiation treatment using Fe ion followed by argon ion at the energy of 70keV and a dose of 1 x 1015 ion/cm2 have been conducted on the surface of two types of thin film, diamond/Si (111) and diamond/Si (100). Both thin films were made by using a CVD method, and the thickness of the thin film is 1000-nm. From simulations using the software called Stopping and Range of Ions in Matter (SRIM), it is known that Fe and Argon ion penetration into the surface of the thin film are respectively 512 and 603 Angstroms. After that the thin film sample was irradiated with ion Fe and Ar, and the property behavior of the morphological change of thin film were studied through Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The grain size range of thin film on diamond films / Si (100) was reduced from 115-322 nm to 147-169 nm, suggesting the effect of irradiation on the surface morphology. The magnetoresistance property is approximately 0.15% at room temperature and magnetic field external H = 0.8 Tesla.

Page 31 of 49 | Total Record : 485

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