Hesti Susilawati
Program Studi Teknik Elektro, Fakultas Sains dan Teknik, Universitas Jenderal Soedirman, Purwokerto 53122

Published : 16 Documents
Articles

Found 16 Documents
Search

RANCANG BANGUN DAN ANALISIS SECTORAL ANTENNA RADIASI SEMICIRCULAR FREKUENSI 2.4GHz UNTUK APLIKASI IEEE 802.11b/g Susilawati, Hesti
Techno Jurnal Ilmu Teknik Vol 13, No 1 (2012): Jurnal Techno April 2012
Publisher : UMP

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Sectoral antenna is a widely used antenna for wireless communications IEEE 802.11b/g  or Wi-Fi due to its large gain and ability to determine covered area.  In this research, a sectoral antenna 2.4GHz frequency with semicircular radiation for IEEE 802.11b/g applications was designed and built.  Design and simulation is done by 4NEC2 software.  In order to get a better performance, the  design was firstly optimized. Antenna parameters studied in this research are Gain, Radiation Pattern H-plane and E-plane, Directivity, Efficiency, and VSWR. Result shown that the simulated performance of sectoral antennaafter optimizationare 13.27 dBi Gain, 120 ° H-plane beamwidth,  10 ° E-plane beamwidth, 15.36 dB Directivity, 95.95% Efficiency, and 1.37 VSWR. While real performance testing of sectoral antenna in the field are 13 dBi Gain, 125 ° H-plane beamwidth, 15 ° E-plane beamwidth, 13.42 dB Directivity, 90.68% Efficiency, and 1.6 VSWR. There are some differences in performance between simulation and application in practice.  Among the causes are the accuracy of manufacturing, quality of materials used, environmental conditions of measurement process, measurement precision, and accuracy of the instrument used. Overall, a sectoral antenna has been created properly and can be used to accomodate 2.4 GHz frequency communication, namely IEEE 802.11b/g. Keywords: antenna, sectoral, semicircular, IEEE 802.11b/g.
IMPLEMENTASI HTB (HIERARCHICAL TOKEN BUCKET) UNTUK MANAJEMEN BANDWIDTH PADA ROUTER INTERNET DI UNIVERSITAS JENDERAL SOEDIRMAN Asmoro, Dwi Ary; Susilawati, Hesti; Nugraha, Azis Wisnu Widhi
Techno Jurnal Ilmu Teknik Vol 12, No 2 (2011): Jurnal Techno Oktober 2011
Publisher : UMP

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

HTB (Hierarchical Token Bucket) bandwidth management implementation on Jenderal Soedirman University is an improvement from PCQ (Per Connection Queue) bandwidth management. PCQ divide traffic automatically based on active users, its weakness is in dividing a large amount of active users. The HTB impelentation refers to Mikrotik RouterOS queue tree, consists of class and parent that is filled by outgoing-interface. Each parent is adjusted based on IP adress block on each node, and determine packet-mark through IP-firewall-mangle. From the implementation result, 2 Global-total or main parent can be obtained, Unsoed down and Unsoed up. 29 Global-in or parent child down and 29 Global-out or parent child up which each parent max-limit is determined by 17,5 Mbps. The users satisfaction based independent sample t-test give the mean value of HTB browsing is 2,823 and PCQ browsing is 2,79. The mean value of HTB downloading is 2,616 and PCQ downloading is 2,636. Those values show that theres no significant differences in Unsoed internet users satisfaction.Keywords : Implementation of bandwidth, Mikrotik RouterOS, queue, parent. 
Simulasi Cell Breathing CDMA 2000 1x Menggunakan DELPHI Hikmaturokhman, Alfin; Susilawati, Hesti; Perdana, Ilham
Jurnal Semesta Teknika Vol 10, No 1 (2007): MEI 2007
Publisher : Jurnal Semesta Teknika

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Cell breathing is variation of CDMA cell size depends upon the amount of traffic occurs within the cell. This work assume that the cell is in the ideal condition based on  the following assumptions,  each cell is completely isolated from the other cells, with the result that no intercell interference and signals from MS cause no interference within the cell. It makes no intracell interference occurs within the cell. In an ideal condition where is none of interference occurs, cell size and amount of users in a cell depend on several factors such as bitrate, required signal strength that MS must deliver to BS, voice activity factor, power control accuracy factor and Eb/It of the system. The result obtained by change the values of the parameters and based on the result obtained, the impact of the parameter to the cell size and amount of user in a cell could be recognized.
Static Hand Gesture Recognition of Indonesian Sign Language System Based on Backpropagation Neural Networks Asriani, Farida; Susilawati, Hesti
Makara Journal of Technology Vol 14, No 2 (2010)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (152.9 KB) | DOI: 10.7454/mst.v14i2.193

Abstract

The main objective of this research is to perform pattern recognition of static hand gesture in Indonesian sign language. Basically, pattern recognition of static hand gesture in the form of image had three phases include: 1) segmentation of the image that will be recognizable form of the hands and face, 2) feature extraction and 3) pattern classification. In this research, we used images data of 15 classes of words static. Segmentation is performed using HSV with a threshold filter based on skin color. Feature extraction performed with the Haar wavelet decomposition filter to level 2. Classification is done by applying the back propagation system of neural network architecture with 4096 neurons in input layer, 75 neurons in hidden layer and 15 neurons in output layer. The system was tested by using 225 data validation and accuracy achieved was 69%.
Peningkatan Efisiensi Penggunaan Bahan Bakar Kendaraan Bermotor Dengan Melakukan Pencarian Jarak Terdekat Menggunakan Jaringan Syaraf Tiruan Hopfield Di Wilayah Purwokerto Mubyarto, Agung; Susilawati, Hesti
Dinamika Rekayasa Vol 6, No 1 (2010): Dinamika Rekayasa - Februari 2010
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2010.6.1.30

Abstract

This proposed research concern with application of continuous Hopfield neural networks for shortest path routing in a given map, in this case Purwokerto city’s map had choosen as an example. The method that was used in this research based on the ability of continuous Hopfield neural networks for representing their neuron as choosen vertices in the given map. The result shows that the networks can produce optimal route for such source and destination node pairs. As the product of this research, we have knowledge about the shortest way from one to another location at Purwokerto, so we can increase the efficiency on fuel use by using this route
Uji Kelayakan Jaringan Lokal Universitas Jenderal Soedirman Untuk Implementasi VoIP Ridwan, Muhamad; Nugraha, Azis Wisnu Widhi; Susilawati, Hesti
Dinamika Rekayasa Vol 7, No 1 (2011): Dinamika Rekayasa - Februari 2011
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2011.7.1.44

Abstract

UNSOED has LAN connection which covers almost all of its units, with minimum bandwidth consupmtionat anaverage of275,318 Kbpsfrom a total of 3 Mbpsso we may apply VoIP system in order to replace voice communication system whichis still using PSTN and PABX. Thereforewe need to know aboutjitter and packet loss ofLAN,and also the codec needs tobedetermined due to voice quality expected and also bandwidth consumpted. Measurementscarried out in two scenariosbased on topologies used in UNSOED (star and ring), in the first scenario (star and ring)server placed on serverfarm meanwhile the second scenario(ring) server placed on Pertanian node. Codec adjusted to the available bandwidth capacity and total of phone number that has to handled. The result show that 0,759 ms jitter obtained from scenario 1 and 0,513ms from scenario 2, both of them included in good category with 0-20 ms of range value, otherwise 0% of packetloss obtained from both scenarios these indicated that LANincluded in good category. There is iLBCcodec with 30 ms packet size which is the mosteconomic on bandwidthcost among G.729, G.711, and iLBC (20 ms), because it cost1995,84Kbpsof total bandwidth usedforhandling 140 phone number. Beside that, it has good voice quality with 4,138996 MOS value. So if we use iLBC (30 ms) codec on the VoIPsystem, there will be still a lot of free bandwidth which can used for other applications, it is about 695,873 Kbps(worst condition) and also get a good-voice quality-VoIP.
Estimasi Kinerja Kanal MIMO-OFDM Menggunakan Modulasi Adaptif Untuk Teknologi LTE Berdasar Pada Kecepatan Pelanggan Purnomo, Widhiatmoko Hery; Susilawati, Hesti; Fadli, Ari
Dinamika Rekayasa Vol 11, No 1 (2015): Dinamika Rekayasa - Februari 2015
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2015.11.1.89

Abstract

OFDM dipakai untuk teknik multiple accesspada downlink LTE. Dalam teknologi LTE, parameter kecepatan user sangat berpengaruh terhadap kualitas jaringan.Pada OFDM, estimasikanalsangatdiperlukan untuk mengatasi fading dan noise.Semakin besar kecepatan user maka semakin besar nilai fading dan noise.Untuk mengatasi masalah tersebut diperlukan estimasi kanal yang digunakan. Metode estimasi kanal yang banyak digunakan ada dua yaitu metode Least Square (LS) dan metode Minimum Mean Square Error (MMSE). Kedua metode tersebut digunakan pada penerima diam dan penerima bergerak dengan modulasi QPSK, 16-QAM, dan 64-QAM. Simulasi dilakukan untuk mengetahui metode estimasi kanal pada beberapa variasi kecepatan user. Hasil analisa menunjukkan bahwa estimasi kanal dengan metode MMSE lebih baik dibandingkan metode LS. Sedangkan pada penerima dengan kecepatan rendah memiliki kualitas jaringan yang lebih baik dibandingkan pada penerima dengan kecepatan tinggi.
Prediksi Penyakit Demam Berdarah Dengue (Dbd) Dan Tifus Menggunakan Jaringan Syaraf Tiruan Perambatan Balik (Back Propagation) Asriani, Farida; Susilawati, Hesti; Harvianti, Lucyana
Dinamika Rekayasa Vol 3, No 1 (2007): Dinamika Rekayasa - Februari 2007
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2007.3.1.122

Abstract

Dengue Haemorrhagic Fever (DHF) and Typhus are diseases which often knock over Indonesian society. Both of these diseases, especially DBD is malignancy that able to result death if losing time to be diagnosed. But civil society, even a doctor which is expert, sometimes also difficult to detect DHF diagnosed earlier, because symptom initially, tending to look like with other acute diseases. One of the diseases that have symptom like DHF is typhus. Back Propagation Artificial Neural Network (ANN) is one of artificial intelligences that can be applicated in the field of health, especially for predicting a disease type. By using input in the form of symptoms the naturalness by a patient, expected this Back Propagation ANN system can help the doctors to diagnose the diseases that happen to their patients, especially DHF and Typhus diseases. ANN system that is designed to predict DHF and typhus diseases, is trained with back propagation algorithm that using adaptive learning rate and momentum. From this research, is got ANN system with network architecture that consist of: one input layer with 18 neurons, one hidden layer with 125 neurons, and one output layer with 1 neuron. And also, value of constanta momentum is 0.95.This ANN system has good performance. From 400 respondents that use for training, result of the memorizing examination reaches percentage equal to 100%, and result of the generalizing examination reaches 96%, from 150 new respondents
Penentuan Pembebanan Maksimum Transformator Daya Yang Menyuplai Personal Computer (PC) Prasetijo, Hari; Susilawati, Hesti
Dinamika Rekayasa Vol 5, No 2 (2009): Dinamika Rekayasa - Agustus 2009
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2009.5.2.21

Abstract

Personal computer is electronic equiment that use solid state device, such as rectifiers, so it to be source of harmonic current. Harmonic current is sinusoidal current with multiple frequency of fundamental current which will be increase power losses because increasing effective current and frequency. In electric distribution system, transformer is component with highest power losses. They are consit of DC losses (Pdc) that influence by effective current, eddy current (PEC) and other stray losses (POSL) which influence by effective current and their frequency. This study involved increasing transformer power losses with assume that transformer supply in full load condition to personal computer. Analyzes following IEEE Std. C57.110-1998 with comparing determination maximum transformer loading use current spectrum from spectrum analyzer equipment and conversion produce Mathlab from current wave time domain to current wave frequency domain. The result are maximum transformer loading is 97,84 use spectrum analyzer and 97,84 use Mathlab sofware.
Initial Tuning Sebagai Salah Satu Metode Pengoptimalan New Site Pada Jaringan Seluler Gsm (Studi Kasus Pada Area Kerja Pt. Sinergi Telecom Under Ericsson Network ) Susilawati, Hesti; Nugraha, Azis Wisnu Widhi; Widodo, Arif
Dinamika Rekayasa Vol 3, No 1 (2007): Dinamika Rekayasa - Februari 2007
Publisher : Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.dr.2007.3.1.124

Abstract

The development of new sites by telecommunication network operator, especially GSM network, purposes for more increase performance and give satisfy for consument. Performance of a site is most affecting for value of network quality totally. New site builded must be monitorized and optimized by its existing in order to can be more realible on serving society with the method that was mentioned “initial tuning activity”. On this method must be concerned some matter as like: application of accurate frequency for avoiding interference problem, creating neighbour relationship between ex isting site and new site, detection for faulth installation for arranging re-use frequency concept, setting accurate coverage, olso changing tilt angle for accurate main beam area. This arrangement must be conditioned on a new site that still “default”, so it can improve quality. On operator side, they have some criteria that must be passed by a new site. Initial tuning activity on Site Simpang RGM had been proved on passing  that site from recommended criteria, olso being totally indicated more increase pe rformance of network