https://ojs.petra.ac.id/ojsnew/index.php/tek <table border="0" cellpadding="7"><tbody><tr><td valign="middle"><a href="/ejournal/index.php/tek"><img style="border-style: none;" src="/ejournal/cover/gematek.jpg" alt="" /></a></td><td valign="top"><p class="style1">Terbit dua kali pada bulan <strong>Maret</strong> dan <strong>September</strong><br />Jurnal <strong>Gematek</strong> sebagai media publikasi/sosialisasi artikel penelitian atau konseptual yang menampung semua karya inovatif dan kreatif berupa perkembangan dan penemuan di bidang Teknik &amp; Sistem Komputer yang meliputi rekayasa perangkat keras dan minimum sistem dalam hardware, diharapkan bisa memberikan Gema yang tidak pernah berhenti dalam dunia Teknik &amp; Sistem Komputer</p></td></tr></tbody></table> en-US Copyright GEMATEK STIKOM ppm@stikom.edu (Jusak Irawan) ppm@stikom.edu (Winarti) Thu, 12 Feb 2009 21:23:17 +0000 OJS 2.4.8.4 http://blogs.law.harvard.edu/tech/rss 60 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16928 Signal Interpreted Petri Net (SIPN) is one of the formal methods to design and to analyze behavior of automation systems. Using SIPN, it can be shown the relationship between developed algorithms and sequential processes. SIPN diagram can then be implemented in general controller hardware such as Programmable Logic Controller (PLC). In this paper, an algorithm for bio-ethanol process production automation system is developed by using SIPN method. The developed algorithm is then analyzed using invariant method. It is found that the resulted automation algorithm achieves high transparency metrics and has no conflicts. Endra Joelianto, Alex Dananjaya Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16928 Thu, 12 Feb 2009 21:25:51 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16927 By serving place for sending and receiving Short Message Service (SMS), can make essier for the public in communicating each other using SMS, although they don’t have any mobile phone or lack of pulse they have. Some electronic text editors based on microcontroller that connected to computer SMS Gateway, can replace mobile phone function as software for sending and receiving SMS. Sending process or reading SMS through SMS Gateway, done by mean of changing text data that come from electronic editor become Protocol Data Units (PDU) data or vice versa. This device could send and display SMS that has been received appropiate user’s request. Ihyauddin Ihyauddin, Tjio Hok Hoo Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16927 Thu, 12 Feb 2009 21:25:17 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16926 The objective this research to design equipment based on computer that can be used as pre -detection or safety in case of fire. Equipment built consists of temperature and smoke, Programmable Pheriperal Interface (PPI) 8255, Analog to Digital Converter (ADC), Digital to Analog Converter (DAC), driver trigger and water spray. Method used in detecting and safety fire using fuzzy system that consists of fuzzification, rule based and defuzzification. The result of experiment shows that air spray automatically function based on the result of temprature and smoke sensor with fuzzy rule applied in the system. Helmy Widyantara Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16926 Thu, 12 Feb 2009 21:24:52 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16925 Digital painting using air brush as a tool to make easier in printing digital picture without printing. This tool consists of: a computer function as image processing and coding image point value as send to the micro controller. Minimal ratio between paint and tinier is used 1:2. The tinier used the easier paint flow out. From the experiment done the result of airbrush painting shows the same as done manual. Mar’i Muhammad Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16925 Thu, 12 Feb 2009 21:24:37 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16924 The GPS was developed by the United States Department of Defense as a reliable means for accurate navigation. The system provides highly accurate position and velocity information and precise time on a continuous global basis to an unlimited number of properly equipped users. By using combined GPS receiver and microcontroller together with radio system, we can design a monitoring system for our vehicles and display the result on the computer. This system consists of a master module that transmites and receives signals from computer and two slave modules to collect GPS data from vehicles. The result of experiment shows that this system is able to track the vehicle on digital map with accuracy as high as 95%. Frenki Harijanto, Helmy Widyantara Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16924 Thu, 12 Feb 2009 21:23:27 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16923  A power transformer has important role in a substation, for transmission and distribution of electric energy to customers. Its performance of reliability should be maintained. Therefore, it is necessary to be monitored in integrated approach continuously. This manuscript presents an integrated monitoring system simulation of power transformer using LabviewTM software, as a description in real condition. On this simulation, it is necessary some inputs, such as frequency, transformer capacity, primary and secondary voltages, load and its power factor. The simulating design needs sensings as sensor or transducer representations. The results are primary and secondary currents and voltages waves, oil and winding temperature charts, frequency, cooling conditions and protection system. They are operated and displayed integratedly. Waluyo Waluyo Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16923 Thu, 12 Feb 2009 21:22:41 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16922 Coating Process Aluminum/chrom in reflector and mirror in PT Astra Otopatrts, on ADIWIRA Plastic Division done using vaccum machine manually. Manually process will cause variation performance process production betweeen from one operator to other operator, this can cause high production rejections. The problem is: “How to make better production process performance that usually done manually”. In this research already designed automatic control system that PLC based in metalizer vaccuum machine for coating process. Designed result can imcrease vaccuum performance with cycle time 1.344 ms (PLC) and 708-893 ms manual system. Suyanto Suyanto, Dedy Yulistyawan Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16922 Thu, 12 Feb 2009 19:06:54 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16921 Keyboard as importance instrumentation and usually use in typeing to compter. Normal person easily can type using both hand, but not for person that has only one hand. So it’s needed tools that can be used easily by hand physical defect person. Many knobs on keyboards that must be used so its need imitation function like SHIFT, CTRL and ALT that can be accessed using foot. The selected knobs because usually used in typing. Tool designed called bridge PS/2 using AT89S51(Atmel, 2003) mikrocontroller. Evaluation done, bridge PS/2 can receive input from foot switch as lenghten knobs for SHIFT, CTRL, or ALT send to the computer through PS/2 port. Yuwono Marta Dinata Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16921 Thu, 12 Feb 2009 19:06:42 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16920 Motor speed controller usually used in industrial, so alot of researches done to make better speed control system. In this paper the used of FuzzIPC (Driver Fuzzy logic for Festo) in controlling DC motor speed. As controller using Festo PLC FC34 type. Constraint of Festo PLC gives Pulse Width Modulation (PWM) that must use external frequency multiplier built using AT89C2051 WITH 12MHz that change PWM signal from PLC to give new PWM signal with higher frequency, but has the same duty cycle. Experiment result shows that frequency multiplier modul output has cbigger multipier factor cycle duty error. The biggest error occur multiplier factor 250. FuzzyIPC used as controller algorithm can give a good control DC motor speed. Frequency multiplier must be revised still has big error. Non-accuracy system in calculating and speed of calculation done by microcontroller. Hany Ferdinando, Hendrik Thiehunan, Julianto Seno Putra Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16920 Thu, 12 Feb 2009 19:06:29 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16919 Short-circuit problem cause higher current than the equipment needed will cause that equipment damage. To overcome that shor-circuit problem needed protection relay that can protect electrical equipment from damage. Protection relay can respond quickly, and not easy damage, flexible and easy to maintain. The used of digital protection relay shows better than conventional protection relay. Digital protection relay is developed to protect bigger system. Microcontroller as digital system can be applied as protection relay by adding some support circuits. The used of microcontroller and current reading circuit in this reasearch gets prototype of digital protection relay designed as transient over curent. This protection relay can protect simple system from short-circuit problem. Heru Dibyo Laksono, M. Nasir Sonni Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16919 Thu, 12 Feb 2009 19:06:17 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16918 The needs of electricity increase rapidly; energy resource from the power plant cannot fulfill those needs. Steam turbine that mostly used is vital equipment in a power plant. This paper presents the result of the numerical study on the frequency control using Neural Network. In operating steam turbine, the stability level frequency is important maintained because has significant effect to the output. Neural Network application has been done the design of neural network controller on the plant. While neural network plant and controller are combined, or online training, then the result is approaching the set point with 0,000899902 errors. Ali Musyafa, A Rachmawardani, Rahmi A Rahmi A Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16918 Thu, 12 Feb 2009 19:06:07 +0000 https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16917 Biometric as one of identification or recognition person techniques that based on uniquely part of human body. Voice one of uniquely human has. Voice signal that come out from different speakers give different voice pattern. Because of high variations used neural network (NNW)for matching the patterns. Before voice data is processed using NNW it’s processed using digital processed through feature extraction phase using discrit wavelet orthogonal base 4 orders with 10 and 15 decomposition rate. The result of NNW is processed by model decision maker that determine speaker identification. The result of experiment shows system biometric built can identify as high as 86% Ketut Agustini Copyright (c) https://ojs.petra.ac.id/ojsnew/index.php/tek/article/view/16917 Thu, 12 Feb 2009 19:05:55 +0000