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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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Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method Sirat, Djamhari; Asvial, Muhamad; Diponegoro, Arman Djohan; Sidharta, Himawan
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method. Pointing accuracy is important in satellite communication. Because the satellite’s distance to the surface of the earth's satellite is so huge, 1 degree of pointing error will make the antenna unable to send data to satellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as the controller, with the GPS as the location indicator of the antenna, a digital compass as the beginning of antenna pointing direction, a rotary encoder as azimuth and elevation censor, and a modem to see Eb/No signal. The microcontroller uses serial communication to read the input. Thus, the programming should be focused on the Universal Asynchronous Receiver/Transmitter (UART) and serial communication software UART. This controller has 2 phases in the process of tracking satellites. The early stage is the elevation-azimuth method, in which with input from the GPS and digital compass, the position of satellites (both coordinates and height) is stored in the microcontroller. The controller will measure the elevation and azimuth angle, then it will move the antenna according to the antenna azimuth and elevation angle. The next stage is correction modem, in which the controller only uses the modem as the input, and antenna movement is set up to obtain the largest value of Eb/No signal. The results of the controller operation show that there is a change in the value of the original input level from -81.7 dB to -30.2 dB with end of Eb/No value reaching 5.7 dB.
Fishing Catch and Catch Rate Assesment of Mini Trawl, Trapnet and Setnet Fisheries Firdaus, Muhammad
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

Fishing Catch and Catch Rate Assesment of Mini Trawl, Trapnet and Setnet Fisheries. This paper is aimed at assessing fishing catch and catch rate of the dragged gear on shrimp, trapnet, and setnet fisheries in Tarakan. The catch and effort data (number and species) and the fishing time of captured units were used in this qualitative analysis of fishing catch and catch rate to describe catch composition and catch rate from three catch fishery units in Tarakan. The result of the research shows that in the catching operation the dragged gear on shrimp has two main catch targets, which are the nomei fish and shrimp in the their two fishing seasons. The nomei fish is also the main catch target in the trapnet fishery, and the pelagic fish inhabiting the estuary and the coastal areas are the main catch target of the setnet fishery. The operation of the dragged gear on shrimp with nomei fish as the main catch target has a catch rate of 16.10 kg/hour and that in the trapnet fishery is 1.67 kg/hour. The catch rate of setnet fishery is 5.39 kg/day and the operation of the dragged gear on shrimp with shrimp as the main catch target has a catch rate of 2.05 kg/hour.
Ontology-Based Automatic Classification for News Articles in Indonesian Language Basnur, Prajna Wira; Sensuse, Dana Indra
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

Ontology-Based Automatic Classification for News Articles in Indonesian Language. Searching specific information will be difficult if relying only on query. Choosing less specific queries will result in a lot of irrelevant information fetched by the system. One of the most successful ways to overcome this problem is to perform document classification based on the topic. There are many methods that can be used to conduct such a classification, such as using statistical and machine learning approaches. However, those document classification methods require training the data or learning the documents. In this study, the authors attempted to classify documents using a method that doesn’t require learning the documents. This classification method uses ontology to classify documents. Document classification using ontology is done by comparing the value of similarity among documents and existing node in the ontology. A document is classified into a category or a node if it has the highest similarity value in one of the nodes in the ontology. The results show that ontology can be used to perform document classification. The recall value is 97.03%, the precision is 91.63%, and the f-measure is 94.02%.
Particle Filter with Binary Gaussian Weighting and Support Vector Machine for Human Pose Interpretation Agustien, Indah; Widyanto, Muhammad Rahmat; Endah, Sukmawati Nur; Basaruddin, Tarzan
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

This paper proposes human pose interpretation using particle filter (PF) with Binary Gaussian Weighting and support vector machine (SVM). In the proposed system, particle filter is used to track a human object, then this human object is skeletonized using thinning algorithm and classified using SVM. The classification is to identify human pose, whether it is normal or abnormal behavior. Here particle filter is modified through weight calculation using Gaussian distribution to reduce the computational time. The modified particle filter consists of four main phases. First, particles are generated to predict target’s location. Second, the weight of certain particles is calculated and these particles are used to build Gaussian distribution. Third, the weight of all particles is calculated based on Gaussian distribution. Fourth, particles are updated based on each weight. The modified particle filter could reduce computational time of object tracking since this method does not have to calculate particle’s weight one by one. To calculate weight, the proposed method builds Gaussian distribution and calculates particle’s weight using this distribution. Through an experiment using video data taken in front of the cashier of a convenience store, the proposed method reduced computational time in tracking process until 68.34% in average compared to the conventional one, meanwhile the accuracy of tracking with this new method is comparable with particle filter method, i.e. 90.3%. Combining particle filter with binary Gaussian weighting and support vector machine is promising for advanced early crime scene investigation.
Petroleum Degradation in Soil by Thermophilic Bacteria with Biopile Reactor Nugroho, Astri; Effendi, Edison; Karonta, Yulius
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

Crude oil degradation has been carried out using biopile reactor in total petroleum hydrocarbon (TPH) concentration of 5%, 10% and 15%. The thermophilic microorganisms used from isolation result and identification are Aeromonas salmonicida, Bacillus pantothenticus, and Stenotrophomonas maltophilia. The biodegradation of biopile reactor is done by various concentrations of TPH, total plate count (TPC), and volatile suspended solid (VSS) per day for 30 days. The biodegradation of kinetic parameter calculated consists of μ, μm, Y, Yt, Yobs, Kd, Ks from TPH concentration decision, and TPC and VSS in every microorganism with t (observation time) of 0 hour to 168 hours. The crude oil separation efficiency in a biople reactor shows that the largest separation occurs in a starting TPH concentration of 15%, which becomes 61.8% later on, followed by a starting TPH concentration of 10% and 5%, which is as much as 61% and 48.4%.
Ergonomic Analysis of UI’s BicyclesUsing Posture Evaluation Index (PEI) Method in Virtual Environment Muslim, Erlinda; Nurtjahyo, Boy; Zulkarnain, Zulkarnain; Afrinotha, Liza
Makara Journal of Technology Vol. 14, No. 1
Publisher : UI Scholars Hub

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Abstract

Ergonomic Analysis of UI’s Bicycles Using Posture Evaluation Index (PEI) Method in Virtual Environment. This research was conducted to study the ergonomic aspect of University of Indonesia’s bicycles in virtual environment. Software Jack 6.0 was used to analyze it. PEI was used as an approach that integrated the results of three methods: lower back analysis (LBA), ovako working posture analysis (OWAS), and rapid upper limb assessment (RULA). The research objective is to evaluate the existing design of University of Indonesia’s bicycles and to determine the most ergonomic redesign which concerns handlebar height and saddle height modification. The result showed that the most ergonomic design of University of Indonesia’s bicycles is the one with the highest handlebar height (22 cm) and the lowest saddle height (11 cm).
Dye Sensitized Solar Cell with Conventionally Annealed and Post-Hydrothermally Treated Nanocrystalline Semiconductor Oxide TiO2 Derived from Sol-Gel Process Yuwono, Akhmad Herman; Munir, Badrul; Ferdiansyah, Alfian; Rahman, Arif; Handini, Wulandari
Makara Journal of Technology Vol. 14, No. 2
Publisher : UI Scholars Hub

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Abstract

Dye-sensitized solar cell (DSSC) is one of the very promising alternative renewable energy sources to anticipate the declination in the fossil fuel reserves in the next few decades and to make use of the abundance of intensive sunlight energy in tropical countries like Indonesia. In the present study, TiO2 nanoparticles of different nanocrystallinity was synthesized via sol−gel process with various water to inorganic precursor ratio (Rw) of 0.85, 2.00 and 3.50 upon sol preparation, followed with subsequent drying, conventional annealing and post-hydrothermal treatments. The resulting nanoparticles were integrated into the DSSC prototype and sensitized with an organic dye made of the extract of red onion. The basic performance of the fabricated DSSC has been examined and correlated to the crystallite size and band gap energy of TiO2 nanoparticles. It was found that post-hydrothermally treated TiO2 nanoparticles derived from sol of 2.00 Rw, with the most enhanced nanocrystalline size of 12.46 nm and the lowest band gap energy of 3.48 eV, showed the highest open circuit voltage (Voc) of 69.33 mV.
An Empirical Model for Build-Up of Sodium and Calcium Ions in Small Scale Reverse Osmosis Nasir, Subriyer
Makara Journal of Technology Vol. 14, No. 2
Publisher : UI Scholars Hub

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A simple models for predicting build-up of solute on membrane surface were formulated in this paper. The experiments were conducted with secondary effluent, groundwater and simulated feed water in small-scale of RO with capacity of 2000 L/d. Feed water used in the experiments contained varying concentrations of sodium, calcium, combined sodium and calcium. In order to study the effect of sodium and calcium ions on membrane performance, experiments with ground water and secondary effluent wastewater were also performed. Build-up of salts on the membrane surface was calculated by measuring concentrations of sodium and calcium ions in feed water permeate and reject streams using Atomic Absorption Spectrophotometer (AAS). Multiple linear regression of natural logarithmic transformation was used to develop the model based on four main parameters that affect the build-up of solute in a small scale of RO namely applied pressure, permeate flux, membrane resistance, and feed concentration. Experimental data obtained in a small scale RO unit were used to develop the empirical model. The predicted values of theoretical build-up of sodium and calcium on membrane surface were found in agreement with experimental data. The deviation in the prediction of build-up of sodium and calcium were found to be 1.4 to 10.47 % and 1.12 to 4.46%, respectively.
The Effect of Enzymatic Hydrolysis on The Properties of Protein Hydrolysate from Paddy Mushroom Palupi, Niken Widya; Windrati, Wiwik Siti; Tamtarini, Tamtarini
Makara Journal of Technology Vol. 14, No. 2
Publisher : UI Scholars Hub

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Abstract

Protein hydrolysate was prepared from Paddy (Volvariella volvaceae) mushroom. Hydrolysis uses commercially protease available Protamex ™ with enzyme concentration of 0.1% (w/w). Hydrolysis was performed at three different temperatures (room temperature, 40 °C, and 50 °C) with different incubation periods (60, 90, and 120 minutes). Enzyme inactivation was done in 90 °C for 3 minutes. Yield and degree of hydrolysis ranged from 94.76% to 99.55% and 19.06% to 24.59%. Protein solubility was about 89–11,8%. The longer time of hydrolysis, the darker the color of protein hydrolysate. Protein hydrolysate which has hydrolysis at 50 °C for 120 minutes has the highest protein yield and the best sensory properties: 4.76 (taste liking), 3.68 (aroma liking), and 4.56 (overall liking). However, this protein hydrolysate has the potential for application as an ingredient in formulated diets.
Effect of Diafiltration on Preparation of Fermented Mung Beans Concentrate as Probiotic Savory Flavor Through Ultrafiltration Membrane Aspiyanto, Aspiyanto; Susilowati, Agustine
Makara Journal of Technology Vol. 14, No. 2
Publisher : UI Scholars Hub

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Diafiltration by means of the ultrafiltration system of probiotic fermented Mung beans (Phaseolus radiatus L.) concentrate has been performed to reduce or eliminate salts and smaller impurities than the nominal cut-off of the membrane of 20,000 nominal weight cut-off (NWCO). These processes have been conducted as an attempt in order to get a probiotic product with organoleptic acceptability, composition, and the optimal total lactic acid bacteria (LAB) counts because the presence of salts will affect on the viability of LAB and the cell lysis of LAB and limit its utility in food products. Concentrate of probiotic mung beans was prepared through fermentation of LAB using inoculum of LAB consisting of Lactobacillus bulgaricus and Streptococcus thermophylus (1 : 1) on fermented mung beans extract inoculated by inoculum of Rhizopus–C1 in rice substrates at salt condition. Ultrafiltration and diafiltration modes have been carried out at flow rate of 8.77 Liter/minute, room temperature and the pressure of 5 bar (0 to 79.7 minutes) and 7 bar (0-154.5 minutes) with the ratio of the volume of pure water to the volume of initial feed (number of diavolume, Nd) of 0, 0.25, 0.5, 0.75, 1.0 and 1.25, respectively. The experiment results based on total LAB counts as a probiotic product show that a high Nd can reduce the salt content but increase the total LAB counts. Nd of 1.0 results reduce the salt content which is equal to retentate, permeate, and the optimal total LAB counts. Ultrafiltration and diafiltration modes at the pressure of 7 bar and Nd of 1.0 give a retentate with total solid of 6.1355%, salt of 1.3515% and remove 86.15% of the salt from probiotic fermented mung beans concentrate and total LAB counts of 10.73 log cycles. Meanwhile, the permeate obtained at this condition results in flux value of 10.83 Liter/m2.hour with contents of total solid of 6.8199%, salt of 1.325% and total LAB counts of 5.49 log cycles.

Page 15 of 49 | Total Record : 485

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