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JURNAL TEKNOLOGI TECHNOSCIENTIA
Published by Institut Teknologi Nasional Yogyakarta
ISSN : 19798415     EISSN : 27148025     DOI : https://doi.org/10.34151/technoscientia.v8i2.161
Core Subject : Science, Engineering,
Earth & Planetary Sciences Engineering
JURNAL TEKNOLOGI TECHNOSCIENTIA dengan ISSN: 1979-8415 dan E-ISSN: 2714-8025 merupakan jurnal ilmiah yang diterbitkan LPPM Institut Sains & Teknologi AKPRIND Yogyakarta sebagai wahana publikasi karya ilmiah/penelitian di bidang teknologi atau rekayasa meliputi bidang teknik kimia, teknik industri, teknik mesin, teknik elektro, teknik informatika, teknik geologi, dan teknik lingkungan, terbit dua kali setahun pada setiap bulan Februari dan Agustus. Setiap naskah yang dikirim akan dilakukan review secara tertutup. Hasil review naskah meliputi: DITOLAK atau DITERIMA DENGAN PERBAIKAN atau DITERIMA. Setiap naskah yang dinyatakan DIITERIMA dan DITERBITKAN dikenakan biaya proses dan cetak sebesar Rp. 250.000,- (di luar biaya pengiriman) dikirimkan via transfer ke: Bank Mandiri Cabang Yogyakarta No.: 137-00-1255210-1 an.: Prof. Dr. Ir. Sudarsono, M.T.
Arjuna Subject : Energi (semua kategori) - Energi (Lain-Lain)
Articles 19 Documents
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Search results for , issue "Academia Ista Vol 12 No 02 Februari 2008" : 19 Documents clear
PENGENALAN POLA SINYAL SEISMIK GUNUNG MERAPI DENGAN ALIHRAGAMGELOMBANG-SINGKAT Saragih, Riko Arlando
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2012

Abstract

In most communication systems, speech was transmitted in narrowband frequency, mainly at frequency 300 Hz to 3400 Hz. Therefore, the frequencies outside this narrow bandwidth were lost. The lost frequencies can cause bias articulation in some speech.Bandwidth expansion is one technique to overcome this problem. Many bandwidth expansion techniques have been developed to increase the speech signal bandwidth on communication channels through envelope aliasing, nonlinear processing, and linear mo-del of human speech processing. Artificial Bandwidth Expansion (ABE) is one of the bandwidth expansion techniques to increase speech signal sampling frequency (upsampling) from 8 kHz to 16 kHz. The process annexes extra spectral components which are the images of the low frequency spectral components (narrowband) in the higher frequency segment. This method works frame by frame and each frame is 30 ms long and 5 ms overlapping with the adjacent frames. In this research, every frame was classified using Hidden Markov Model (HMM) and stated as sibilants or fricative consonants or stop consonants and treated separately (attenuated or amplified) according to the classification results.Comparison tests were done in this research based on the audio perceptions of so-me responders. Based on the results, it was acknowledged that the quality of the speech signal was significantly improved although some distortions were somewhat object-ttionable.
PENGENALAN POLA SINYAL SEISMIK GUNUNG MERAPI DENGAN ALIHRAGAM GELOMBANG-SINGKAT Novianta, Muhammad Andang
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2013

Abstract

Seismogram data from the monitoring representative the raw file in contain vario-us each information about circumstance perceived. The wavelet transform is methode can by us for indicating data and operator function in the different frequency element. Pattern recognition process seismic signal using wavelet transform have the higher level efficacy opportunity. By the wavelet enable time-frequency location. Thresholding method to limit and eliminate some part on the signal which are not important. By determining value of data parameter, the parts of limited the can be considered by a mixed noise.
MENGGALI POTENSI ALIRAN AIR SUNGAI SEBAGAI SUMBER TENAGA PEMBANGKIT LISTRIK MIKROHIDRO; STUDI KASUS : SUNGAI KALI MANGGIS DI WILAYAH MAGELANG Nisworo, Sapto; Setyowati, Endang
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2015

Abstract

People are becoming more dependent on electric energy in their daily life. Waterfall is one potential primary source of energy. Kali Manggis river has to potential for a PLTM (Pembangkit Listrik Tenaga Mikrohidro) system used waterfall method. The research was to explore this potential quantitatively.This research used positivistic method with a hypothesis that Kali Manggis river is good potential of energy. Discharge of water and the height of waterfall were measured and the analysis of data will give quantity energy.The findings show that Kali Manggis river was a lot of power for electric energy. The electrical energy force in the Kali Manggis river was 1.503,8222179 kwh.
VOLKANISME DAN KEPUNAHAN MANUSIA PURBA DI KOMPLEK GUNUNG PATIAYAM, DESA JEKULO, KECAMATAN KUDUS, JAWA TENGAH Mulyaningsih, S.; Bronto, S.; Kusnaedi, A.; Simon, I.; Prasetyanto, I. W.
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2016

Abstract

Geomorphologically, Mount Patiayam is a dome. The dome is characterized by varrying in strike-dips, the dipping layers of the southern part is to south, the eastern part is to east, the northern part is to north and the western part is to west. The summit of the dome is composed of igneous rock of pyroxenic basalt, while fluvial deposits and shale are composing of flanks up to foot of the dome. Based on the composing rocks, there were volcanism processes within Mount Patiayam. The interpretation was also supported by Landsat image that showed depression-shapes in caldera rings-like.Furthermore, Pleistocene sediments contain vertebrate and hominid (Homo erectus) fossils that are exposed at Patiayam region. Those fossils occur within cross bedding structure of pumiceous breccia, fine up to very coarse tuffs, and clay tuffs.
PEMBUATAN DAN KARAKTERISASI BIODIESEL DARI MINYAK BUNGA MATAHARI DAN METANOL DENGAN KATALIS NaOH -, Sukamta; Endriyani, Sunarti; Anita, Fitri
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2017

Abstract

Biodiesel is fuel made of seed oil and has potential to be used as substitute of crude oil. In this experimental work, it was used sun flower seed oil as a raw material of biodiesel.The aims of the research were to study a transesterification reaction of trigli-seryde of a sun flower seed oil and methanol and to attain the optimum conditions of the process to produce good quality of biodiesel. This research were done by mixing sun flower seed oil, methanol and catalyst with oil and methanol volume ratios were 1: 6 and 1:9 respectively. The ester produced were then characterised. The experiments resultant showed that the best quality of biodiesel were attained when the volume ratio between oil and methanol was 1:6 at temperature of reaction of 50oC and time of reaction of 90 minute. The characteristic of the oil produced were specific gravity 60/60 °F = 0,8846 ; viscosity kinematic = 4,562 cSt; pour point = 25,7°F ; flash point = 115 °F, and conversion of 32,42%. This characteristic in the range of the standard of biodiesel based on the letter of Ketua Badan Standarisasi Nasional No.04 – 7182 – 2006 about biodiesel.
STUDI EKSPERIMENTAL PENGARUH PENAMBAHAN BACK SPOILER MODEL NACA 0015 TERHADAP KARAKTERISTIK AERODINAMIKA PADA MOBIL MERCEDES BENZ SLK 320 -, Syamsuri
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2018

Abstract

Generally a vehicle moving against fluid stream will get aerodynamic force. A vehicle must have a high performance to be up against aerodynamic force, these forces will effect its response and stability especially when the vehicle running fast. Stability parameter is determined by the value of lift coefficient or Cl of vehicle. In addition, it is also expected to have minimum drag coefficient or CD. The value of both coefficients can be described through flow characteristics around the vehicle. Aerodynamic force is most affected by drag force and lift force that dependent to the vehicle contour. The aerodynamic performance can be controlled by modifying the characteristic of the vehicles, either one is modifying vehicle body. This study learns adding naca 0015 back spoiler to the Mercedes Benz slk 320. A model type sedan of 1 : 18 scale is tested on wind tunnel under conditions velocity flow 8 m/s, 10 m/s, 12 m/s, 14 m/s, 14 m/s, 16 m/s, 18 m/s and angle of airfoil 00, 50, 100, 150, 200, 250. by adding naca 0015 back spoiler to the Mercedes Benz SLK 320 vehicle will reduce the drag force and lift force so it gets a better characteristic aerodynamic performance. Pressure distribution of the flow was observed centre line of upper and beside right and left of the model vehicle. Result of the experiment indicated that instalment of spoiler NACA 0015 did not influence significantly the pressure distribution on the model. And the result of this research shows that additional accessory has a unique effect on the aerodynamic force
OPTICAL CHARACTER RECOGNITION DENGAN METODE JARINGAN SARAF TIRUAN BACKPROPAGATION Lestari, Uning
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2019

Abstract

Artificial Neural Network is one of algorithms that is often used in intelligent system. These algorithms build a system based on biology Artificial Neural Network which is similar to human brain in solving a problem. Many applications based on Artificial Neural Network (ANN) have been developed in all areas especially in Pattern recognition. One of ANN is back propagation that is supervised learning. This training process is done by upgrading also achieving some targets. The implementation of character pattern recognition is as an application for pattern character recognition from A-Z which function to analyze sample data in image form (BMP file) that will be changed into grayscale. These conversion will produce character in document that gives benefit for process information in text that has already saved in images so that it can be edited or erased based on user needs.
TEKNOLOGI TEPAT GUNA TEMPAT PEMBAKARAN SAMPAH RUMAH TANGGA DENGAN TANAH LIAT -, Warsiyah
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2020

Abstract

Orchard Gondanglutung, Donoharjo, Ngaglik, Sleman, Yogyakarta represents a high population region with a lot of garbage that pollutes environment. The writer is very interested in handling the problem by doing this research entitled. The Incinerator of Domestic Garbage with Clay.The method used factor of efficiency of processing or wet garbage draining and dry garbage combustion and to the number of ash yielded and also combustion chamber by using proper technological appliance utilize the combustion of domestic garbage with clay. Result of research showed the highest combustion and draining efficiency were garbage with 0,5 kg weight with the combustion efficiency 92,06 %, while wet garbage with 3,5 kg weight combustion efficiency was 35,23%.From the research It can be concluded that the greater volume of garbage in the draining and combustion process will decrease combustion efficiency.
PENGARUH TEMPERATUR PADA NILAI THDF (TRANSFORMER HARMONIC DERATING FACTOR ) DALAM TRANSFORMATOR DISTRIBUSI Handajadi, Wiwik
JURNAL TEKNOLOGI TECHNOSCIENTIA Academia Ista Vol 12 No 02 Februari 2008
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v0i0.2021

Abstract

Based on the previous research it can be seen that the load of a distribution transformer which was sinked in water showed that the THDF value is greater than one, and this is an advantage to optimize the use of the transformer.This research analysed the effects of the increase temperature in load at the transformator distribution. The effects of harmonic were calculated based on the de-crease of the performance of the transformator, i.e. operating capacity of the trafo that is called THDF (The Transformer Harmonic Derating Factor). The results of the experiment showed that the increase of the temperature was not significant to the THDF. The water that was asummed as a cooling media was not true. it was a media to increase the quality of grounding system that can reduce the effect of harmonic in transformator distribution.

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