IPTEK The Journal of Engineering
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Strain Sensing Comparison Between Single and Multimode Fibers using Optical Low Coherence Interferometry
Full text linkOptical low coherence interferometry is one of the accurate optical sensing technologies and widely utilized in various physical sensing properties. The system principle is to characterize the relative interferogram movement distance caused by the various strain on a sensing arm. An interferometric strain sensor from two-stage Mach-Zehnder interferometer was demonstrated for double sensitivity improvement. The strain performance comparison between single and multimode fibers will be analyzed for fiber sensing applications. The stepper motor was set up with a movement distance of 20 nm in every step and the velocity could achieve 10000 step/s. The fiber strain was characterized as 22.22 με on a 9-cm length. The experimental results demonstrated the multimode fiber sensitivity is higher than single mode fiber. Repeatability of both single and multimode are uncertain. The interferogram movement distance from the multimode fiber was higher than a single mode and demonstrates higher sensitivit
The Comparisson between LBP and SQI Methods in the Surface Roughness Measurement Using ESPI Method
Full text linkSurface roughness measurement using direct contact methods raises several issues, for examples stylus wear and size limitation problems. Furthermore non-contact methods are proposed to solve these problems. One of them is Electronic Speckle Pattern Interferometry (ESPI), which use Helium-Neon (He - Ne) as laser light source. A speckle pattern is produced by scattered light on the surface of the measuring object due to the interference of laser beams, and it will be captured by Charge Coupled Device (CCD) camera. Afterwards Linear Binary Pattern (LBP) and Self Quotient Image (SQI) methods are used to reduce illumination effect in the captured image. The average gray-level from the previous process will be converted into a surface roughness value by gray level to surface roughness conversion formulation. It is obtained from correlation value between gray level and a set of standard roughness. The standard roughness value range is start from 0,05 μm to 12,5 μm. It is measured from five different final machining process, which are flat lapping, grinding, horizontal milling, and vertical milling. As verification, the results of ESPI method will be compared with the result of direct contact tools using Mitutoyo Surftest 301 and 401
Opinion Extraction of Public Figure Based on Sentiment Analysis from Twitter
Full text linkTwitter is a microblog that can generate an information from users such as sentiment about public figures. Sentiment analysis of public figure interpret the positive or negative response. This study aims to create system that automatically can extract the opinion about public figure based on sentiment analysis in twitter using two novel features, they are specific term and number of followers public figures lover and hater. Several step to determine the sentiment of public figure are preprocessing, weighting, classifying, and determining sentiment response. In this paper we use six public figures to be observed. This research resulting precision 99%, recall 75%, and accuracy 76,67%
Tin Extraction from Slags Used Hydrochloric Acid
Full text linkSlag is a mixture of mineral in tin sand or by product in the smelting process. By using separation process, tin can be separated from other minerals in slag. Extraction process with a solvent is usually used to separate tin from other minerals. Furthermore, solution that still contains many dissolved compounds is adsorbed by activated carbon and desorption back with NaOH solution. This study only focuses on the extraction process to obtain a stannate chloride solution with extraction temperature, solvent concentration, extraction time, and liquid/solid ratio as variables. Hydrochloric acid (HCl) has been used as solvent in this study. The concentration of tin in the extracts of each variable was analyzed to determine the percentage of recovery of tin and the optimum operating conditions in the recovery process of tin from waste slag. Experiment results show that the percentage of recovery increases with the increasing of extraction temperature and solvent concentration The highest recovery is 61.5% which is obtained when the extraction temperature is 80 ºC, concentration of HCl is 10 wt%, with a HCl solution and slag ratio is 7: 1 and extraction time is about 30 minutes
Implementation of Genetic Algorithm for Parameter Tuning of PID Controller in Three Phase Induction Motor Speed Control
Full text linkInduction motor at low speeds has a tough speed setting sets the width of the range. This study tested by giving the load motor disorders to describe the condition. The method used for vector control system so that the resulting performance is good at setting the motor speed and torque. This method is used in setting the Proportional Integral Derivative (PID) Tuning parameter settings based on Genetic Algorithm (GA) to provide a dynamic response to changes in speed and load torque on the motor, so we get smoothness at any speed change and braking and maximum torque motors. Optimization function is required to obtain a new PID parameter values each input value changes or load disturbances, in terms of the initial determination of these parameters using Ziegler-Nichols method based on frequency response. Tests were performed at a speed of approximately 1800 rpm value rise time of about 10 seconds after generation added, at a rate of 1800 rpm rise time value of the average remains around 9 seconds, but slightly reduced the oscillations in the response, and the speed of approximately 1700 rpm rise time value of the average is 9 seconds. The test results show that GA-based PID controller has a good response in approximately 0.85% overshoot at the motor speed change and brakin
Auto Berthing – a Solution for Achieving Zero Waiting Time at Harbour
Full text linkTanjung Perak Port is one of biggest harbour in Indonesia. The shipping start from Karang Jamuang to Naval Base. The moving is use help of scout ships and tug boat. A control system can be applied to anchored ships , to replace the role of tug and scout boat. Movement from the parking position to the anchored involve auto maneuver and auto berthing. Both auto system is designed using fuzzy logic control. Input of control from sensors and guidance according to the path leading to the dock, and to anticipate the environmental disturbance factors (that is ocean currents). Control rules are unique, according to the type and size of vessel. In the case study to AHTS vessels, berthing auto show good ability. The heading error of 0.04° to the direction parallel to the dock, and the range of distances error is 0.16 to 2.16 meters from the desired position. Reduction of processing time leaning point to Jamrud dock is 33 minutes