Niyartama T.F.,State Islamic University of Yogyakarta |
Fauzi U.,Physics of Earth and Complex Systems |
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.
Anwari A.,State Islamic University of Yogyakarta |
Nahdi M.S.,State Islamic University of Yogyakarta |
Sulistyowati E.,State Islamic University of Yogyakarta
AIP Conference Proceedings | Year: 2016
Local wisdom as product of local knowledge has been giving a local context in science development. Local wisdom is important to connect scientific theories and local conditions; hence science could be accessed by common people. Using local wisdom as a model for learning science enables students to build contextual learning, hence learning science becomes more meaningful and becomes more accessible for students in a local community. Based on this consideration, therefore, this research developed a model for learning biology based on Turgo's local wisdom on managing biodiversity. For this purpose, Turgo's biodiversity was mapped, and any local values that are co-existing with the biodiversity were recorded. All of these informations were, then, used as a hypohetical model for developing materials for teaching biology in a senior high school adjacent to Turgo. This research employed a qualitative method. We combined questionnaries, interviews and observation to gather the data. We found that Turgo community has been practicing local wisdom on using traditional plants for many uses, including land management and practicing rituals and traditional ceremonies. There were local values that they embrace which enable them to manage the nature wisely. After being cross-referenced with literature regarding educational philoshophy, educational theories and teachings, and biology curriculum for Indonesia's senior high school, we concluded that Turgo's local wisdom on managing biodiversity can be recommended to be used as learning materials and sources for biological learning in schools. © 2016 AIP Publishing LLC.
Kustiati,University of Tanjungpura |
Aji O.R.,Ahmad Dahlan University |
Kurniatanty I.,State Islamic University of Yogyakarta
AIP Conference Proceedings | Year: 2016
The house fly Musca domestica L. on urban garbage dump played role as a mechanical vectors of infectious diseases caused by bacteria. The aim of this study was to identify the diversity of bacteria on house flies from garbage dump in Bandung. Nutrient medium was used for isolation and culture of bacteria followed by observation of morphological and Gram stain. Genotyping and sequencing bacterial genomic DNA were performed by using a primer 16S rRNA gene. Molecular phylogenetic analysis placed of the isolates into three species, viz. Exiguobacterium indicum, Serratia sp. and Morganella morganii subsp. morganii, which were pathogenic bacteria. This is the first report of a bacterial species residing in Musca domestica L. in Indonesia. Here, we signified that house flies on a garbage dump in Bandung carry pathogenic bacteria. © 2016 Author(s).
Anwar M.,Indonesian Institute of Sciences |
Anggraeni A.S.,Indonesian Institute of Sciences |
Amin M.H.A.,State Islamic University of Yogyakarta
AIP Conference Proceedings | Year: 2017
Developing highly environmentally friendly and cost-effective approaches for the chitosan production has paramount important in the future technology. Deacetylation process is one of the most importing steps to classify the quality of chitosan. This research aimed to study the best method for deacetylation of chitin considered by several factors like the concentration of base, temperature, time and reaction method. From the green chemistry point of view, conventional refluxing method relatively wasted energy compared to another method such as maceration, grinding and sonication. The degree of deacetylation (DD) of chitosan was studied by sonication, resulted in slightly increasing of DD from 73.14 to 73.28% during the time from 0.5 h to 1 h. Deacetylation of chitin with various sodium hydroxide concentration 60, 70 and 80% gave 73.14, 76.36 and 77.88% of DD, respectively. Variation of temperature at 40, 60, and 80°C was slightly affected on increasing DD from 67.53, 72.84 and 73.14%, respectively. The DD of chitosan significantly increased from 60.19, 74.27 and 81.20% respectively correspondent to varying NaOH concentration 60, 70 and 80% using the maceration method. Solid phase grinding method for half hour resulted in 79.49% of DD. The application of ultrasound grinding method not only was enhanced toward the deacetylation but also favoured the depolymerization process. Moreover, maceration for 7 days with 80% NaOH can be as an alternative method. © 2017 Author(s).
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.
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.