State Islamic University of Yogyakarta
Yogyakarta, Indonesia

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Diniarsih S.,Gadjah Mada University | Jones S.,Jl. Patimura No. 8 Gang Melati 2X | Setiyono J.,State Islamic University of Yogyakarta | Noske R.,University of Queensland
Kukila | Year: 2016

Starlings rose Pastor roseus not been recorded in Indonesia, but never recorded in Sabah, eastern Malaysia as a kind of nomad. These birds recorded in the park near Ambarukmo Plaza Yogyakarta and in coastal areas Serangan Island, Bali in the migration season 2013-2014. These birds are thought to migrate together starling starling China and the Philippines. While it can not be ascertained, the starling sales rose in Yogyakarta indicates the possibility that individual is removable birds. However, this encounter became the first record for this type in Indonesia.

Niyartama T.F.,State Islamic University of Yogyakarta | Fauzi U.,Physics of Earth and Complex Systems | Fatkhan,Geophysics Engineering
Journal of Physics: Conference Series | Year: 2017

Laboratory measurements of Ultrasonic P-wave velocities were conducted in weakly compacted sandstone with varying degree of water saturations. We used P wave transducer at frequency 63 kHz and imbibition technique in order to study the influence of water saturation on the P-wave velocity. Our experiment showed that the P-wave velocity (Vp) was reduced significantly at the beginning of the imbibition process. The variations on travel times and the amplitude changes were detected at any degree of saturation. The first and second amplitude of P wave decreased as water saturation (Sw ) increased in the range of 0.1 to 0.6 in B5 sample, the amplitude increased again afterward. The shifting peaks of the signal that indicated attenuation were also observed in the experimental. © Published under licence by IOP Publishing Ltd.

Taufiq Nuruzzaman M.,State Islamic University of Yogyakarta | Lee C.,Chonnam National University | Abdullah M.F.A.B.,Multimedia University | Choi D.,Chonnam National University
Security and Communication Networks | Year: 2012

The amount of Short Message Service (SMS) spam is increasing. Various solutions to filter SMS spam on mobile phones have been proposed. Most of these use Text Classification techniques that consist of training, filtering, and updating processes. However, they require a computer or a large amount of SMS data in advance to filter SMS spam, especially for the training. This increases hardware maintenance and communication costs. Thus, we propose to filter SMS spam on independent mobile phones using Text Classification techniques. The training, filtering, and updating processes are performed on an independent mobile phone. The mobile phone has storage, memory and CPU limitations compared with a computer. As such, we apply a probabilistic Naïve Bayes classifier using word occurrences for screening because of its simplicity and fast performance. Our experiment on an Android mobile phone shows that it can filter SMS spam with reasonable accuracy, minimum storage consumption, and acceptable processing time without support from a computer or using a large amount of SMS data for training. Thus, we conclude that filtering SMS spam can be performed on independent mobile phones. We can reduce the number of word attributes by almost 50% without reducing accuracy significantly, using our usability-based approach. © 2012 John Wiley & Sons, Ltd.

Nuruzzaman M.T.,State Islamic University of Yogyakarta | Lee C.,Chonnam National University | Choi D.,Chonnam National University
Proceedings - 11th IEEE International Conference on Computer and Information Technology, CIT 2011 | Year: 2011

The amount of Short Message Service (SMS) spam is increasing. SMS spam should be put into the spam folder, not the inbox. Some solutions have been proposed that for the most part use Text Classification techniques. However, they need another computer system to create the filtering system using a large amount of SMS data in advance and install the filtering system into the mobile phone to filter incoming SMS. This kind of solution reduces independence because the user has to store received SMS into computer to train or update the filtering system or data and user can get the filtering system. Storing SMS, which may consist of private data especially SMS ham, leads to privacy problem. Obviously, it also increases hardware cost and increases communication cost between mobile phone and computer system. Thus, we propose an independent filtering system that does not need computer system support. The training, filtering and updating processes were done on mobile phone. Our proposed approach filters SMS spam on an independent mobile phone while obtaining reasonable accuracy, minimum storage consumption and acceptable processing time. © 2011 IEEE.

Rahmayanti M.,State Islamic University of Yogyakarta | Santosa S.J.,Gadjah Mada University | Sutarno,Gadjah Mada University
International Journal of ChemTech Research | Year: 2016

Gallic acid-modified magnetite particles (Mag-GA) were synthesized via reverse coprecipitation method. The obtained Mag-GA were characterized by Fourier Transform Infrared spectroscopy and X-Ray diffraction. FTIR characterization for Mag-HA after modification indicated the presence of specific absorption bands for functional groups of humic acid and Fe-O bonds, though with lower intensity than before modification. The XRD patterns showed that the crystalinity of magnetite before modification were higher than after modification with gallic acid. The mechanism of synthesis was assumed to occur through electrostatic bonding between the surface of magnetite and gallic acid. The Mag-GA particles were applied for AuCl4-adsorption and results showed that the optimum adsorption of [AuCl4]-onto Mag-GA was found at pH 3. The mechanism of gold recovery using Mag-GA particles takes place through the formation of hydrogen bonding followed by reduction of trivalent gold ions to metallic gold, which is accompanied by simultaneous oxidization of the hydroxyl groups of gallic acid. This assumption was supported by FTIR spectra, XRD chromatogram and photo-optical microscope that showed the presence of metallic gold on Mag-GA after adsorption. © 2016 Sphinx Knowledge House. All right reserved.

Uyun S.,State Islamic University of Yogyakarta
Journal of Theoretical and Applied Information Technology | Year: 2016

Image thresholding is one of image processing techniques to help analyze the next phase. Consequently, choosing a precise method in this step is quite-essential. Image blurs and bad illumination are common constraints that often influence the effectiveness of the thresholding method. Fuzzy sets is one among other perceptions in scoring an image. Thus, various thresholding fuzzy techniques have been developed to eliminate those constraints. This paper proposes the improvement of multilevel thresholding techniques by using type II fuzzy sets with the function of gaussian membership to access some objects at mammogram to get fibroglandular tissue areas. The result shows that the proposed technique has a very good achievement with the average score with misclassification error parameter of 97.86%. This proves that the proposed algorithm are able to function well to the image with low contrast level and high unclearness level. © 2005 - 2015 JATIT & LLS. All rights reserved.

Fajriati I.,State Islamic University of Yogyakarta | Mudasir,Gadjah Mada University | Wahyuni E.T.,Gadjah Mada University
Indonesian Journal of Chemistry | Year: 2014

The photocatalytic decolorization of methyl orange (MO) by TiO2-chitosan nanocomposite has been studied. This study was started by synthesizing TiO2-chitosan nanocomposites using sol-gel method with various concentrations of Titanium(IV) isopropoxide (TTIP) as the TiO2precursor. The structure, surface morphology, thermal and optical property of TiO2-chitosan nanocomposite were characterized by X-ray diffraction (XRD), fourier transform infra red (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and diffuse reflectance ultra violet (DRUV) spectroscopy. The photocatalytic activity of TiO2-chitosan nanocomposite was evaluated by photocatalytic decolorization of methyl orange as a model pollutant. The results indicate that the particle size of TiO2increases with increasing of the concentration of TTIP, in which TiO2with smallest particle size exhibit the highest photocatalytic activity. The highest photocatalytic decolorization was obtained at 5 h of contact time, initial concentration of MO at 20 ppm and at solution pH of 4. Using these conditions, over 90% of MO was able to be decolorized using 0.02 g of TiO2-chitosan nanocomposite under UV light irradiation. The TiO2-chitosan nanocomposite could be reused, which meant that the TiO2-chitosan nanocomposites can be developed as an effective and economical photocatalyst to decolorize or treat dye in wastewater. © 2014 Gadjah Mada University. All Rights reserved.

Dewi A.S.,State Islamic University of Yogyakarta
Internetworking Indonesia Journal | Year: 2011

This article aims to describe the application of local e-Government by the Government of Terong, Bantul District, Yogyakarta Province, Indonesia. The method used in the research is case study. This research shows that the government of Terong has succeed to develop community based e-government model, namely Sistem Informasi Desa (SID/Village Information System). This model is a result of media convergence which already exist, such as community radio, community news letter and citizens forum. Besides media convergence, involvement of all elements in Terong played important role in the development of SID. Strong leadership and good will from local government also contributed to the process of SID. The result of this effort is better public service by local government. These findings conclude that bureaucratic reform can occur with the help of ICT.

'Uyun S.,State Islamic University of Yogyakarta | Riadi I.,Ahmad Dahlan University
Telkomnika | Year: 2011

As the education fees are becoming more expensive, more students apply for scholarships. Consequently, hundreds and even thousands of applications need to be handled by the sponsor. To solve the problems, some alternatives based on several attributes (criteria) need to be selected. In order to make a decision on such fuzzy problems, Fuzzy Multiple Attribute Decision Making (FMDAM) can be applied. In this study, Unified Modeling Language (UML) in FMADM with TOPSIS and Weighted Product (WP) methods is applied to select the candidates for academic and non-academic scholarships at Universitas Islam Negeri Sunan Kalijaga. Data used were a crisp and fuzzy data. The results show that TOPSIS and Weighted Product FMADM methods can be used to select the most suitable candidates to receive the scholarships since the preference values applied in this method can show applicants with the highest eligibility.

Widodo,State Islamic University of Yogyakarta | Luthfi M.J.,State Islamic University of Yogyakarta
Biodiversitas | Year: 2016

Fagraea ceilanica Thunb. population were found in the Mount Nglanggeran in Gunungkidul, Yogyakarta, Indonesia. Identification was based on the literature and herbarium specimens. The study was conducted through continued exploration and examination on specimen collection. The existence of F. ceilanica in Java was only described in Flora of Java by Backer and Bakuizen van den Brink (1965). Fagraea ceilanica is a liana climbing on large stone. Characteristic for initial identification were ovate to ellipsoid leaves which were opposite, thick and grayish green; bell-trumpet flower shape with flowering season around March and whitish to yellowish color and also 5-8 cm corolla tube. This paper presents important morphological character, namely leaves, stems, flowers, and fruits of F. ceilanica. Study on morphological character of F. ceilanica found on Mount Nglanggeran is needed to recognize its potential, benefit and conservation of this species. © 2016, Dove Medical Press Ltd. All rights reserved.

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