Lala Septem Riza
Department of Computer Science Education, Universitas Pendidikan Indonesia, Bandung

Published : 9 Documents

Found 9 Documents

Jurnal Ilmu Komputer (JIK) Vol 1, No 1 (2013): Jurnal Ilmu Komputer (JIK)
Publisher : Ilmu Komputer

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Identifikasi telapak tangan dapat berpengaruh untuk keamanan data. Identifikasi telapak tangan diimplementasikan dengan menggunakan metode Jaringan Syaraf Tiruan Learning Vector Quantization. Ada 4 langkah dalam mengidentifikasi telapak tangan. Langkah pertama dimulai dengan menggunakan metode image processing grayscalling dari data gambar berwarna dan menghasilkan data gambar grayscale sebagai input untuk langkah kedua. Langkah kedua yaitu menggunakan metode image processing edge detection dan menghasilkan beberapa piksel edge dalam data gambar grayscale sebagai input untuk langkah ketiga. Langkah ketiga yaitu menggunakan metode image processing thresholding dan menghasilkan data array biner. Langkah keempat yaitu menggunakan metode Jaringan Syaraf Tiruan Learning Vector Quantization pada data array biner dan menghasilkan data array bobot. Data array bobot ini yang dihitung untuk mengidentifikasi telapak tangan. Studi kasus dilakukan dengan menggunakan maksimal 240 buah data pembelajaran, 160 buah data pengujian, dan 4 buah parameter sensitity yang menghasilkan akurasi keberhasilan sebesar 37,25% untuk perubahan epoh, 35% untuk perubahan jumlah data pembelajaran, 32,625% untuk perubahan learning rate, 24,22% untuk perubahan nilai threshold. Akurasi keberhasilan yang kecil dikarenakan  posisi telapak tangan yang berubah-ubah. Kata Kuncipengenalan dan identifikasi telapak tangan, Jaringan Syaraf Tiruan Learning Vector Quantization, image processing grayscalling, image processing edge detection, image processing thresholding.
Determining Trending Topics in Twitter with a Data-Streaming Method in R Mediayani, Melani; Wibisono, Yudi; Riza, Lala Septem; Pérez, Alejandro Rosales
Indonesian Journal of Science and Technology Vol 4, No 1 (2019): IJOST: VOLUME 4, ISSUE 1, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i1.15807


Trending topics in Twitter is a collection of certain topics that are widely discussed by users. This study aims to design a model and strategy for finding trending topics from data streams on Twitter. The research approach was carried out in four stages, namely twitter data collection, preprocessing data, data analysis with sequential K-Means clustering and information processing. Sequential K-Means is used because it can receive input data sequentially and the cluster center can be updated. Testing of the model is carried out in three scenarios where each scenario is distinguished between the amount of data, time and parameter values. After that, evaluation of the results of clustering will be done using the Dunn Index method. Trending topics twitter application were created using the R language and produce output in the form of histograms. There are five topics being the trending topics in New York before the new year. The topic of "Times" relates to the presence of a new year's celebration night concert in Times Square. The "Hours" topic deals with the calculation of time and seconds towards 2017. "Eve" and "Party" topics relate to celebrations and the topic "Resolution" relating to hope and change for New Yorkers in in 2017.
COUNTING INTERACTIVE MEDIA FOR CHILDREN WITH AUTISM Riza, Lala Septem; Solihat, Syifa; Fitriasari, Novi Sofia; Homdijah, Oom Siti; Nurhayati, Ai Siti; Hidayat, Topik
Jurnal Pengajaran MIPA Vol 23, No 1 (2018): Jurnal Pengajaran MIPA - April 2018
Publisher : Faculty of Mathematics and Science Education, Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18269/jpmipa.v23i1.13908


Learning for children with autism must specifically cater to their unique characteristics but learning media specifically tailored to the characteristics of children with autism is unfortunately still limited. We designed and implemented interactive learning media using Picture Exchange Communication System (PECS) method to children with autism in one of special education schools in Bandung-Indonesia. Students? improvement was evaluated after learning and their response?s while learning were documented. Results showed an improvement in students' learning achievement after learning using the interactive media and students also responded positively to the learning media in which they showed great interest in learning with the designed media.
Working Volume and Milling Time on the Product Size/Morphology, Product Yield, and Electricity Consumption in the Ball-Milling Process of Organic Material Nandiyanto, Asep Bayu Dani; Andika, Riezqa; Aziz, Muhammad; Riza, Lala Septem
Indonesian Journal of Science and Technology Vol 3, No 2 (2018): IJoST: Volume 3, Issue 2, 2018
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v3i2.12752


Analysis of ball-milling process under various conditions (i.e. working volume, milling time, and material load) on the material properties (i.e. chemical composition, as well as particle size and morphology), product yield, and electricity consumption was investigated. Turmeric (curcuma longa) was used as a model of size-reduced organic material due to its thermally and chemically stability, and fragile. Thus, clear examination on the size-reduction phenomenon during the milling process can be done without considering any reaction as well as time-consuming process. Results showed that working volume is prospective to control the characteristics of product. Working volume manages the shear stress and the collision phenomena during the process. Specifically, the lower working volume led to the production of particles with blunt-edged morphology and sizes of several micrometers. Although working volume is potentially used for managing the final particle size, this parameter has a direct impact to the product yield and electricity consumption. Adjustment of the milling time is also important due to its relation to breaking material and electrical consumption.
Question Generator System of Sentence Completion in TOEFL Using NLP and K-Nearest Neighbor Riza, Lala Septem; Pertiwi, Anita Dyah; Rahman, Eka Fitrajaya; Munir, Munir; Abdullah, Cep Ubad
Indonesian Journal of Science and Technology Vol 4, No 2 (2019): IJOST: VOLUME 4, ISSUE 2, 2019
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v4i2.18202


Test of English as a Foreign Language (TOEFL) is one of learning evaluation forms that requires excellent quality of questions. Preparing TOEFL questions in conventional way certainly spends a lot of time. Computer technology can be used to solve the problem. Therefore, this research was conducted in order to solve the problem of making TOEFL questions with sentence completion type. The built system consists of several stages: (1) input data collection from foreign media news sites with excellent English grammar quality 2) preprocessing with Natural Language Processing (NLP) (3) Part of Speech (POS) tagging (4) question feature extraction (5) separation and selection of news sentences (6) determination and value collection of 7 features (7) conversion of categorical data value (8) target classification of blank position word with K-Nearest Neighbor (KNN) (9) heuristic determination of rules from human experts (10) options selection or distraction based on heuristic rules. After conducting the experiment on 10 news, it obtained that 20 questions based on the results of the evaluation showed that the generated questions have very good quality with percentage of 81.93% after the assessment by the human expert, and 70% the same blank position from the historical data of TOEFL questions. So, it can be concluded that the generated question has the following characteristics: the quality of the result follows the data training from the historical TOEFL questions, and the quality of the distraction is very good because it is derived from the heuristics of human experts.
Parallel random projection using R high performance computing for planted motif search Riza, Lala Septem; Dhiba, Tyas Farrah; Setiawan, Wawan; Hidayat, Topik; Fahsi, Mahmoud
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 17, No 3: June 2019
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (533.988 KB) | DOI: 10.12928/telkomnika.v17i3.11750


Motif discovery in DNA sequences is one of the most important issues in bioinformatics. Thus, algorithms for dealing with the problem accurately and quickly have always been the goal of research in bioinformatics. Therefore, this study is intended to modify the random projection algorithm to be implemented on R high performance computing (i.e., the R package pbdMPI). Some steps are needed to achieve this objective, ie preprocessing data, splitting data according to number of batches, modifying and implementing random projection in the pbdMPI package, and then aggregating the results. To validate the proposed approach, some experiments have been conducted. Several benchmarking data were used in this study by sensitivity analysis on number of cores and batches. Experimental results show that computational cost can be reduced, which is that the computation cost of 6 cores is faster around 34 times compared with the standalone mode. Thus, the proposed approach can be used for motif discovery effectively and efficiently.
Fuzzy Rule-based Classification Systems for the Gender Prediction from Handwriting Riza, Lala Septem; Zainafif, Aldi; Rasim, Rasim; Nazir, Shah
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 16, No 6: December 2018
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (506.713 KB) | DOI: 10.12928/telkomnika.v16i6.9478


The handwriting is an object that can describe information about the author implicitly. For example, it is able to predict the gender. Recently, the gender prediction based on handwriting becomes an interesting research. Even in 2013, an competition for prediction gender from handwriting has been held by Kaggle. However, the accuracies of current approaches are relatively low. So, in this study, we attempt to implement Fuzzy Rule-Based Classification Systems (FRBCSs) for gender predictions from handwriting. Three stages are conducted to achieve the objective, as follows: defining some features based on Graphology Techniques (e.g., pressure, height, and margin on writing), collecting real datasets, processing on digital images (i.e., image segmentation, projection profiles, and margin calculation, etc.), and implementing FRBCSs. The implemented algorithm based on FRBCSs in this research is Chi’s Algorithm, which is a method based on Fuzzy Logic for classification tasks. Moreover, some experiments and analysis, involving 75 respondents consisting of 36 males and 39 females, have been done to validate the proposed model. From the simulations, the classification rate obtained is 76%. Besides improving the accuracy rate, the proposed model can provide an understandable model by utilizing fuzzy rule-based systems.
A Simple, Rapid Analysis, Portable, Low-cost, and Arduino-based Spectrophotometer with White LED as a Light Source for Analyzing Solution Concentration Dani Nandiyanto, Asep Bayu; Zaen, Rena; Oktiani, Rosi; Abdullah, Ade Gafar; Riza, Lala Septem
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 16, No 2: April 2018
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (546.152 KB) | DOI: 10.12928/telkomnika.v16i2.7159


The purpose of this study was to demonstrate a simple, rapid analysis, portable, and inexpensive spectrophotometer. Different from other spectrophotometers, the present instrument consisted of a single white light-emmiting-diode (LED) as a light source, a light sensor, and arduino electronic card as an acquisition system. To maintain a constant light intensity, a common white-color LED emitting a 450-620 nm continous spectrum was employed. Software was written in C++ to control photometer through a USB interface and for data acquistion to the computer. The instrument is designed to be simple and compacted with sizes of 200 x 130 x 150 mm for length, width, and height, respectively. The analysis of the total cost isabout less than 500 USD, while commercially available offers price of more than 10,000 USD. Thus, this makes the present instrument feasible for teaching support media in developing countries. The effectiveness of the present spectrophotometer for analyzing solution concentration (i.e. curcumin) was also demonstrated. Interestingly, the present spectrophotometer is able to measure the concentration of curcumin precisely with an accuracy of more than 90%. Different from commercially available standard UV-visible spectrophotometers that have limitations in the analysis of concentration of less than 50 ppm, the present system can measure the concentration with no limitation since the measurement is based on the LED light being penetrated.
Indonesian Journal of Science and Technology Vol 5, No 1 (2020): IJOST: VOLUME 5, ISSUE 1, 2020
Publisher : Universitas Pendidikan Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17509/ijost.v5i1.18754


This  study  aimed  to  design  a  batik  learning  medium  for vocational high school students in based on multiplatform. The application  made was expected  to support heutagogy approach ? based learning and to deal with the development of  science  and  technology  integrated  in  the  curriculum  of vocational high schools. The application developed, namely e-botik,  was  an  integration  of  several  previously-designed applications using Code ignitor (CI) framework. The database used was My-SQL. It is commonly known that Code igniter is an open source web application framework utilized to create dynamic PHP applications. In this study, e-botik consisted of three main  components  including interface, database,  and application  programming  interface  (API).  Some  of  the applications combined were ARtikon_joyful (Android-based), Video Kasumedangan Batik (movie player), Nalungtik  Batik (desktop-based),  Digi_Learnik  (web-based),  Batik  UPI (manual),  Batik  Cireundeu  (manual),  and  Lembar  Balik (manual). The combination proceeded web-based so that it was  compatible  with  various  operating  systems.  The application (e-botik) was designed and then tested. The test was  performed  through  whitebox  testing  and  blackbox testing. The results of the test showed that it ran well and was able to be used a batik learning media. It is expected that students  can  utilize  e-botik  in  selecting  topics  of  learning batik in accordance with their competences and needs. This condition enables e-botik to support learning batik through heutagogical approach. In addition, the application was also validated in terms of both system and usage aspects.