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KERAMIK PORSELEN BERBASIS FELDSPAR SEBAGAI BAHAN ISOLATOR LISTRIK

10.12928/telkomnika.v7i2.580
Eva; Universitas Diponegoro Indiani , Ngurah Ayu Ketut; Universitas Diponegoro Umiati
Electric solid insulator based on ceramics porcelain had been made by using local raw materials: 68% feldspar, 10% kaolinite and 22% quartz, and also added 0%, 5%, 10%, 15%, 20%, 25% cullet (From total mass). The forming process of the porcelain was conducted by milling the raw materials using ball mill and screened using 200 mesh screening. The samples were formed by using the dry-press method with the pressure of 50MPa, then the samples is sintered at temperature of 1000oC, 1050oC, 1100oC, 1150oC for 2 hours. The properties of the samples had been analyzed for their  shrinkage, density, bending strength and resistivity. The result of the experiment showed that the optimum value was reached by ceramic which was added by 15% cullet and sintered at temperature of 1100oC. This ceramic had shrinkage of 9,70%, density of 2,44 g/cm3, bending strength of 86,73 MPa and the resistivity at 25oC is 2,32x108 Ωcm
Volume: 7
Issue: 2
Page: 83-92
Publish at: 2009-08-01

SISTEM INFORMASI VIA SMS GATEWAY ANTARA PIHAK KEPOLISIAN DENGAN PENGEMUDI

10.12928/telkomnika.v7i2.584
Ratna; Politeknik Elektronika Negeri Surabaya – Institut Teknologi Sepuluh Nopember Adil
Sum up accident sacrifice at January period of up to August 2007 progressively mount and primary factor of cause the happening of accident is human being factor, one of them is missing driver of awareness. To lessen this accident number, one of them is earn conducted by killing car machine in order to the missing driver of awareness cannot animate its car machine as well as communications with party police. The making of information system via SMS Gateway of between party police with driver, expected to by earn to overcome the problem. In this system, there are two sides that is side of driver and side police. Data of co-ordinate of position vehicle taken by GPS then is delivered through SMS of through server/police. That Data co-ordinate then is presented at digital map. Data of number Vehicle delivered through SMS to server and kept in database. With exploiting technology GPS (Global Positioning System), Microcontroller, GSM Modem, MapInfo, and Microsoft Office Access for the data intake, conducted a examination several times in place which equal to time difference about minute half, so that be got by a difference apart between position result of examination with data of reference of Google Earth of equal to more or less one meter. Others also be happened by the data deviation between position got from intake of data GPS with position vehicle which in fact (reference data from Google Earth). The based on result of examination which have been conducted in place location park D3 PENS ITS differ from position vehicle which in fact and happened by the position deviation more or less four transversal meter on course south (- 7,165614°) and the east longitude (112,476011°).
Volume: 7
Issue: 2
Page: 119-128
Publish at: 2009-08-01

A NOVEL APPROACH FOR CONFIGURING THE STIMULATOR OF A BCI FRAMEWORK USING XML

10.12928/telkomnika.v7i2.579
Indar; Petra Christian University Sugiarto
In a working BCI framework, all aspects must be considered as an integral part that contributes to the successful operation of a BCI system. This also includes the development of robust but flexible stimulator, especially the one that closely related to the feedback of a BCI system. This paper describes a novel approach in providing flexible visual stimulator using XML which has been applied for a BCI (brain-computer interface) framework. Using XML file format for configuring the visual stimulator of a BCI system, we can develop BCI applications which can accommodate many experiment strategies in BCI research. The BCI framework and its configuration platform is developed using C++ programming language which incorporate Qt’s most powerful XML parser named QXmlStream. The implementation and experiment shows that the XML configuration file can be well executed within the proposed BCI framework. Beside its capability in presenting flexible flickering frequencies and text formatting for SSVEP-based BCI, the configuration platform also provides 3 shapes, 16 colors, and 5 distinct feedback bars. It is not necessary to increase the number of shapes nor colors since those parameters are less important for the BCI stimulator. The proposed method can then be extended to enhance the usability of currently existed BCI framework such as BF++ Toys and BCI 2000.
Volume: 7
Issue: 2
Page: 73-82
Publish at: 2009-08-01

ANALISIS SIFAT HIDROFOBIK PERMUKAAN HDPE BERDASARKAN NILAI TOTAL HARMONIC DISTORTION

10.12928/telkomnika.v7i2.583
Abdul; Universitas Diponegoro Syakur , Hermawan; Universitas Diponegoro Hermawan , Sarjiya; Universitas Gadjah Mada Sarjiya , Hamzah; Universitas Gadjah Mada Berahim
Polymer material has been developed to replace the porcelain insulator material and glass. When it is used as outdoor insulator, environmental conditions have a significant influence to the value of surface discharge current, especially for the coastal area and industry. Salt, dust and chemicals contaminant are suspected as the causes of initial current of surface discharge and the insulator surface degradation which lead to a flashover. To analyze the performance of the insulator surface when the leakage current occurs, the Total Harmonic Distortion (THD) is needed to be determined. The value of THD leakage current indicates the hydrophobic characteristic of surface material. This paper analyzes the results of leakage current measurement in laboratory-scale based on IEC 587:1986 with Inclined-Plane Tracking (IPT) method to the High Density Polyethylene (HDPE) polymer material which is provided in smooth and rough surface. The testing voltage is 50 Hz AC. Data of leakage current magnitude values cover its maximum average as a function of time and the result of FFT to the wave form of the leakage current. As the result, the value of percentage THD decrease as the function of time. The smooth surface material has THD value 43.42% and the rough surface has 15.89%.
Volume: 7
Issue: 2
Page: 109-118
Publish at: 2009-08-01

PURWARUPA SISTEM PEMBATAS KECEPATAN SEPEDA MOTOR BERBASIS MIKROKONTROLER AT89S52

10.12928/telkomnika.v7i2.582
Ikhsan; Universitas Ahmad Dahlan hidayat , Abdul; Universitas Ahmad Dahlan Fadlil , Edy; Universitas Ahmad Dahlan Fathurrozaq
Security riding is very important in the aspects of traffic. One of the main factors of traffic accidents is high speed. Therefore, it is required a speed restraint equipment for pressing the number of accidents. The car speed restraint system is available in the market, but on a motorcycle is not available yet. This paper presents a design of speed restraint equipment for motorcycle that safe for users, and is expected to reduce traffic accident. The Main idea this speed restriction is cutting off the flow of electrical signals from the pulser (the time ignition trigger sensor) to the CDI for 1 second. The cutting Signal with mechanical relays controlled by microcontroller AT89S52 using the on-off algorithm. Speed sensor use optocoupler is used to detect the number of rounds wheel motorcycle. If a result of measurement is more than the speed setpoint, microcontroler make a decission to cut motorcycle ignition signal. Results of this research is a prototype speed restraint shown that it able to process data from the measurement of the speed limit on the speed of a motorcycle. This prototype safe for all users and accordance with the set value and the level of success is above 90% for speed of 10 km/hr to 40 km/hr.
Volume: 7
Issue: 2
Page: 103-108
Publish at: 2009-08-01

IMPLEMENTASI MIKROKONTROLER SEBAGAI PENCACAH FREKUENSI BERBASIS PENGUKURAN PERIODE ISYARAT MASUKAN

10.12928/telkomnika.v7i1.577
Freddy; Sekolah Tinggi Teknologi Adisutjipto (STTA) Kurniawan
One of the main components from frequency counter is a processor. This processor must have ability to conduct counting and arithmetical calculation. To get competitive price, in this research a microcontroller is applied as a processor. This paper presents design of frequency counter based on microcontroller AT89S51 which has two independent timers. The input frequency counter is conducted by using facilities inside microcontroller e.g. T0 and external interruption. Counter method used in this research is by measuring input signal period. This method is proven effectively to count frequency especially low frequency. As the result, the frequency counter has successfully measured frequency from 0.1 until 10 kHz with maximum error 1%. This device is possible to be the next frequency counter with competitive price.
Volume: 7
Issue: 1
Page: 57-64
Publish at: 2009-04-01

MATLAB/SIMULINK BASED ANALYSIS OF VOLTAGE SOURCE INVERTER WITH SPACE VECTOR MODULATION

10.12928/telkomnika.v7i1.572
Auzani; Universiti Teknikal Melaka Malaysia (UTeM) Jidin , Tole; Universitas Ahmad Dahlan (UAD) Sutikno
Space vector modulation (SVM) is the best modulation technique to drive 3-phase load such as 3-phase induction motor. In this paper, the pulse width modulation strategy with SVM is analyzed in detail. The modulation strategy uses switching time calculator to calculate the timing of voltage vector applied to the three-phase balanced-load. The principle of the space vector modulation strategy is performed using Matlab/Simulink. The simulation result indicates that this algorithm is flexible and suitable to use for advance vector control. The strategy of the switching minimizes the distortion of load current as well as loss due to minimize number of commutations in the inverter.
Volume: 7
Issue: 1
Page: 23-30
Publish at: 2009-04-01

PENINGKATAN KECEPATAN PROSES PADA METODE COLOR ORDERING DAN MAPPING DENGAN PENDEKATAN DELAPAN-KETETANGGAAN

10.12928/telkomnika.v7i1.576
Astried; Universitas Riau Astried , Tri Basuki; Universitas Bina Darma Kurniawan
The development of digital technology and internet, nowadays, has given the facility for easy access and distribution of a lot of information in digital form. The facilities in distributing digital data also has emerged the negative impact such as the violence of copy right. One of techniques developed from negative impact is water making technique. Several techniques have been mentioned by many researches in water making, one of them is the use of color palette and color index which is also know as ordering and mapping color method. In this method, the substitute color found through all colors in the pallets so this process gives the longer time in bit watermark inserting process. In this paper, ordering and mapping color which use color pallet of an image will be modified to increase the speed of the process by using eight neighborhoods approximation. From experimental result conducted to 30 images, it can be concluded that the proposed approximation has taken the shorter time than the conventional method. 
Volume: 7
Issue: 1
Page: 51-56
Publish at: 2009-04-01

STUDI PENENTUAN NILAI RESISTOR MENGGUNAKAN SELEKSI WARNA MODEL HSI PADA CITRA 2D

10.12928/telkomnika.v7i1.571
Didik; Universitas Negeri Yogyakarta Hariyanto
2D image is a form of image which has coordinates x and y, and override the factors of depth (coordinate z). In an image, there is a color information that consisting of components Red, Green, and Blue (RGB). Color information can be used as a medium for a computer program to interpret objects or values as well as the value of resistor color. By using the color information, a resistor value can be count based on bracelet color. To get good results, RGB color model need to be changed to HSI (hue, saturation, Intensity) color model first. Hue value represent the actual color, saturation level indicates the color saturation, and intensity is used to determine the number of light. By using the color selection based on HSI model and determined the value of threshold, it can be used to express the amount of resistor value in the form of a digital image.
Volume: 7
Issue: 1
Page: 13-22
Publish at: 2009-04-01

APLIKASI MOBILE SMS GATEWAY OVER GPRS UNTUK MENGAKSES SISTEM INFORMASI

10.12928/telkomnika.v7i1.575
Wahyu; Universitas Ahmad Dahlan Pujiyono , Arif; Universitas Ahmad Dahlan Rahman , Ananta; Universitas Ahmad Dahlan Wijaya
SMS via GPRS technology can be used to access data from information systems. This technology is one of regular and premium SMS extensions. The SMS over GPRS is composed by three components: the mobile application, server, router and gateway of information systems. The research objective was to build a mobile application to access information systems with the assumption that the server and the gateway router of information systems already exist. System was built using the http protocol, which has a request-response mechanism. There are two methods in the delivery of the message (request) and the receipt of the message (response) from the server, the message filtering and message parsing. Filtering is used to filter the message text /string that not known to be a string known by http, and then in message parsing process, message parses in the form of XML.
Volume: 7
Issue: 1
Page: 43-50
Publish at: 2009-04-01

SOUND OF PADDLE WHEEL ON SEA BASS GROWTH

10.12928/telkomnika.v7i1.570
Sunardi; Universiti Teknologi Malaysia, Universitas Ahmad Dahlan Sunardi , Anton; Universiti Teknologi Malaysia, Universitas Ahmad Dahlan Yudhana , Ahmad Syahril Mohd; Universiti Teknologi Malaysia Nawi , Jafri; Universiti Teknologi Malaysia Din , Saberi; Universiti Teknologi Malaysia Mawi
The objective of this research is sound effect for brackish water for Sea bass (Cynoscion nobilis). Breeding farm 25x100m, 2m of depth, and 6 paddle wheels which generate the sound are available for research. Sound profile has been measured to investigate the amplitude at various measurement points at various depths by using Cetacean hydrophone C304. The output of hydrophone has been analyzed by using SpectraPlus software. For the second measurement, two cages which size 3x3m have been used for life fish habitat. Then, fish put in the edge cage (20), center cage (20), and out of cage (12500). Sound profile has been measured for position-based (edge/center cage), time-based (morning/noon/evening), and point-based. Time series, spectrum frequency, and phase have been analysis. Fish growth progress has been monthly measured at every cage. Fish in the cage is growth as linearly, while fish growth for out of cage is exponentially. Size and weight of fish in the both cages is less than out of cage. This research concludes that sound have no significantly effect for fish growth. Limited mobility to look for food and stress are more influences to fish growth than sound effect.
Volume: 7
Issue: 1
Page: 1-12
Publish at: 2009-04-01

SIMULASI PEMBANGKITAN SINYAL 8–PHASE SHIFT KEYING BERBASIS MATLAB

10.12928/telkomnika.v7i1.574
Indah; Universitas Mercu Buana Yogayakarta Susilawati
Phase Shift Keying (PSK) is simply the allocation of one fixed phase for every code in the bit streams. In BPSK modulation, it’s needed to allocate two distinct phases for “1” and “0”. In QPSK modulation, it’s needed to allocate four distinct phases, each for “01”, “01”, “10”, and “11”. While in 8 – PSK, it’s needed to allocate eight distinct phases, each for “000”, “001”, “010”, “011”, “100”, “101”, “110”, and “111”. Bandwidth efficiency in BPSK is 1 b/s/Hz and 2 b/s/Hz in QPSK. While in 8 – PSK, bandwidth efficiency achieved is 3 b/s/Hz. Higher efficiency bandwidth means narrower bandwidth needed for data transmission.  This simulation is used to generate 8 - PSK signals using Matlab software tools. The results show that the simulation is able to generate BPSK and QPSK signals perfectly.
Volume: 7
Issue: 1
Page: 37-42
Publish at: 2009-04-01

RANCANG BANGUN DIPLEKSER UNTUK PEMANCAR TELEVISI ULTRA HIGH FREQUENCY (UHF)

10.12928/telkomnika.v7i1.578
Trie; Sekolah Tinggi Teknologi Nasional Yogyakarta Handayani
The development of television technology in Indonesia has growth rapidly. This fast growth is marked by the presence of 10 private television stations. Establishing a television station requires a lot of expense especially to build transmitter and tower antenna. This paper presents a research to design and built the diplexer system for merging two transmitter signals transmitted by an antenna transmitter. This design is conducted by using two copper pipes with diameter 3.2 cm and 1.4 cm. The use of different sizes of diameter is intended to obtain impedance characteristic (ZO) equal to 50 Ω. The copper pipe is designed to form a system diplexer with open and close end of transmission. There are two mixing frequency tested, those are 620 MHz ( at terminal A) and 600 MHz (at terminal B). The result shows that terminal A acts as a band pass filter for frequency around 620 MHz and a filter stop band for frequency around 600 MHz . Terminal B acts as a band pass filter for frequency around 600 MHz and as a stop band for frequency around 620 MHz. Based on the results obtained,  this diplexer can be applied to merge two television transmitters with carrier frequency of 600 MHZ and 620 MHz within a single antenna.
Volume: 7
Issue: 1
Page: 65-72
Publish at: 2009-04-01

ANALISIS PENGGUNAAN JARINGAN KABEL LISTRIK SEBAGAI MEDIA KOMUNIKASI DATA INTERNET

10.12928/telkomnika.v7i1.573
Imam; Universitas Mercu Buana Yogyakarta Suharjo
The main function of power network is used to deliver electrical energy to meet energy needs. Although this grid has opportunity to use as line transmission that it was only for analog communication and telemetry originally. In the development of research and technology, this network can be used for digital data communications at speeds high enough. In this study conducted a test of feasibility analysis, especially in the use of electricity for the internet data communication. The low voltage electricity network is used in this research. Results from this study, among the tested electrical network on the short distance of less than 400 meters can be used for data communication with the media either. However, if it is used for a more remote distance, the quality will decrease. The real distance depends to the testing equipment and quality of electricity. 
Volume: 7
Issue: 1
Page: 31-36
Publish at: 2009-04-01

SIMULATOR LENGAN ROBOT ENAM DERAJAT KEBEBASAN MENGGUNAKAN OPENGL

10.12928/telkomnika.v6i3.569
Balza; Universitas Gadjah Mada Achmad , Musthofa; Universitas Gadjah Mada Sunaryo , Agus; Universitas Gadjah Mada Arif
A robot simulator has been developed, that capable in simulating a 6 degree of freedom robot manipulator. Using this simulator, a user can define the type and angular range of the joints, and length of each link, as well as the colors. User can also select an arbitrary viewing angle and move the robot manually or automatically. The simulator was developed using C++ programming language utilizing OpenGL graphic library. Denavit-Hartenberg notation was used as parameters to specify the shape and size of the manipulator.
Volume: 6
Issue: 3
Page: 209-216
Publish at: 2008-12-01
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