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INDONESIA
EKSAKTA: Journal of Sciences and Data Analysis
Published by Universitas Islam Indonesia
ISSN : 27160459     EISSN : 27209326     DOI : 10.20885
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Materials Science & Nanotechnology
Ekstakta is an interdisciplinary journal with the scope of mathematics and natural sciences that is published by Fakultas MIPA Universitas Islam Indonesia. All submitted papers should describe original, innovatory research, and modelling research indicating their basic idea for potential applications. The Journal particularly welcomes submissions that focus on the progress in the field of mathematics, statistics, chemistry, physics, biology and pharmaceutical sciences.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 231 Documents
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Evaluasi Unjuk Kerja Alat Spektrofotometer UV-Vis Menggunakan Holmium Oksida dan Kalium Dikromat Thorikul Huda; Cecep Sa'bana Rahmatillah; Yusuf Habibi
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 12, ISSUE 1, February 2011
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

The Evaluation of Hitachi U 2010 UV-Vis Spectrophometer performance using holmium glass  from  Starna  reference materials  and  potassium  dichromate  has  been  done.    The  aim  of investigation with holmium glass was to known wavelength work region at ultra violet and visible area,  potassium  dichromate  solution  used  to  known  photometric  performance  of  UV-Vis spectrophotometer.   The  result of  investigation used holmium glass showed wavelength peak at 241,  278,  287,  333,  360,  418,  445,  453, 459,  536  and  637  nm  regions, wich  it  is  similar with reference material.  The determination of photometric resulted by absorbance value measurement at  235,  275,  313  and  350  nm  were  0,746;  0,860;  0,294;  0,641  respectively.      The  result  of wavelength  and  photometric  investigation  showed  that Hitachi U  2010  spectrophotometer was proper to done and suitable with SR 03 KAN reference.  Keywords:  UV-Vis  Spectrophometer,  holmium  glass,  potassium  dichromate,  wavelength,
Clustering Provinces in Indonesia based on Community Welfare Indicators Sekti Kartika Dini; Achmad Fauzan
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 1, ISSUE 1, February 2020
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol1.iss1.art9

Abstract

The Preamble of the 1945 Constitution of the Republic of Indonesia explicitly states that the main task of the government of the Republic of Indonesia is to advance general prosperity, to develop the nation's intellectual life, and to realize social justice for all Indonesian people. Social inequality is a problem that is still faced by Indonesian people today. To solve the problem required supporting data analysis as a basis for policy formulation. This research was conducted with the aim of clustering provinces in Indonesia based on community welfare indicators using K-Means cluster analysis. K-Means cluster analysis is chosen based on the variance value (0.101), which is smaller than the variance value in the average linkage cluster analysis (0.152). Based on data analysis, provinces in Indonesia are clustered into three where the first cluster consists of 21 provinces, the second cluster consists of 3 provinces, and the third cluster consists of 10 provinces. Each cluster has different characteristics that can be of concern to the parties concerned to overcome the social welfare gap. Besides, in order cluster results are more easily understood, visualization of results is added with a Geographic Information System (GIS) using Indonesian maps accompanied by differences in color gradations for each cluster
Segmentasi Bayesian Hirarki Untuk Model Ma Konstan Sepotong Demi Sepotong Berbasis Algoritma Reversible Jump Mcmc Suparman, Suparman
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 11, ISSUE 1, February 2010
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

This paper addresses the problem of the signal segmentation within a hierarchical Bayesian framework by using reversible jump MCMC sampling. The signal is modelled by piecewise constant MA processes where the numbers of segments, the position of abrupt, the order and the coefficients of  the MA processes for each segment are unknown. The reversible jump MCMC algorithm is then used to generate samples distributed according to the joint posterior distribution of the unknown parameters. These samples allow to compute some interesting features of the a posterior distribution. Main advantage of the algorithm reversible jump MCMC algorithm is produce the joint estimators for the parameter and hyper parameter in hierarchical Bayesian.  The performance of the this methodology is illustrated via several simulation results.   Keywords :     Hierarchical Bayesian model, Reversible Jump MCMC methods, Signal  Segmentation, piecewise constant Moving-Average (MA) processes
Effect of Temperature on Rice Husk Asing and Its Application on Adsorbing Fe and Zn Metal in Patchouli Oil Ahmad Said; Is Fatimah; Dwiarso Rubianto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 14, ISSUE 2, August 2014
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol14.iss2.art7

Abstract

Telah dilakukan studi pengaruh temperatur pembuatan adsorben abu sekam padi (ASP) dan aplikasinya pada adsorbsi logam Fe dan Zn dalam minyak nilam. Variasi temperatur pengabuan dilakukan pada 300, 500, dan 7000C selama 2 jam. Variasi temperatur pengabuan bertujuan mengkarakterisasiadsorben ASP. Karakterisasi yang dilakukan yakni penentuan silika secara gravimetri, diameter pori, morfologi abu dan komposisi unsurdengan teknik SEM/EDS,dan adsorptivitas terhadap metilen biru secara spektrofotometri. Tiga varian ASP diaplikasikan pada pemurnian minyak nilam dengan metode adsorbsi. Rendemen ASP-300, ASP-500, dan ASP-700 yang dihasilkan secara berurutan yaitu 35,4%, 25%, dan 16,5%. Kadar silikanya sebesar 43,12%, 72,12% dan 87,7%. Adsorbtivitas terhadap MB diperoleh 1,1616 mg/g, 0,7507 mg/g, dan 0,4128 mg/g. Diameter pori rata-rata antara 4,4 – 6,8μm. ASP mampu memurnikan minyak nilam dengan metode adsorbsi. Warna, bobot jenis, indeks bias, dan kadar logam Fe serta Zn pasca adsorbsi telah memenuhi standar mutu minyak nilam SNI. ASP-700 adalah adsorben paling baik dibandingkan ASP-500 dan ASP-300 dalam pemurnian minyak nilam.
Utilization of Waste Extracts Residual Tobacco Cigarette Manufacturing and Leaves of Mahkota Dewa as a Natural Pesticide for Pest Control Armyworms in Chili Plant Cahyati Cahyati; Marlina Marlina Marlina; Rizqy Nurlestari Nurlestari; Indrasti Dwi Puji lestari; Tatang Shabur Julianto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 16, ISSUE 2, August 2016
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol16.iss2.art2

Abstract

The use of pesticides is still considered behind a great benefit for increasing agricultural production. Quite high negative impact of the use of synthetic pesticides to encourage efforts to pursue the empowerment of natural pesticide as alternative to synthetic pesticides. On tobacco and leaves of mahkota dewa found a substance alkaloid that can help ward off attacks, especially armyworm. Has conducted research utilization of waste residual tobacco cigarette manufacturing at a company and leaves of mahkota dewa as a natural pesticide to eradicate the armyworm. The residual tobacco cigarette manufacturing and leaves of mahkota dewa isolated manner extracted with an organic solvent so that the resulting crude extract alkaloids. The resulting crude alkaloid used as a pesticide solution sprayed on the leaves of chili to eradicate the pest armyworms. Test result showed that the insecticidal activity of alkaloid extract concentration of 1,6 ppm has the highest insecticidal activity. However, engaging both the alkaloid extract provides insecticidal activity is lower than the alkaloid extract of leaves of mahkota dewa so that the most effective in the use of alkaloid extract of leaves of mahkota dewa. Identification of the alkaloid compounds have been analyzed by TLC. This analysis showed that compound in waste of tobacco cigarette manufacture is nicotine and triterpenoids whereas the alkaloid extract of the leaves of mahkota dewa form of narcotic
Solvent Optimization For Genistein Isolation Of “Rotten Tempe” By High Performance Liquid Chromatography Method Cucun Alep Riyanto; Hartati Soetjipto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 17, ISSUE 2, August 2017
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol17.iss2.art3

Abstract

Genistein is a soy isoflavone that has been known have anticancer properties. The aim of this research is to determine the right combination of solvents to extract isoflavones in rotten tempe and determine the genistein content of the extraction process by the High Performance Liquid Chromatography (HPLC) method. Isoflavone extraction process was done using a mixture of methanol and chloroform solutions. Isoflavone extracts obtained will be analysed using High Performance Liquid Chromatography (HPLC) method to determine the content of genistein. The optimum isoflavone extract was obtained from chloroform:methanol (10:1 v/v) solvent ratio. Where as the highest contents of genistein from the 4th day “rotten tempe” as 26.199 ± 25.146 (mg/g).
Forecasting The Exchange Rate (IDR) of US Dollar (USD) Using Locally Stationary Wavelet Dina Tri Utari
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 18, ISSUE 2, August 2018
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol18.iss2.art6

Abstract

Currency exchange rate of a country to the other countries is fluctuative. The movement of the exchange rate affects the country’s economy. The exchange rate can change any time according to the market mechanism, therefore currency exchange predictions is required to determine future economic policy. Based on the impact of exchange rate in economy fluctuations, an accurate model is needed to determine the exchange rate movements.In this case, the model is Locally Stationary Wavelet (LSW). This model combines stocastic process class based on wavelet non decimated. LSW model can catch most of the information in time series data. Based on the application of LSW mtehod on the data of the rupiah against the US dollar for the period April 2016 - March 2017, it can be concluded that model provides forecasting results approaching actual data therefore it can be used for forecasting exchange rates. The value of the mean absolute percentage error (MAPE) is 0,1201293%. 
Parameter Estimation in Probit Model for Multivariate Multinomial Response Using SMLE Jaka Nugraha
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 12, ISSUE 1, February 2011
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

In  the  research  field  of  transportation,  market  research and  politics,  often involving  the  response  of  the multinomial multivariate  observations.  In  this  paper, we discused  a  modeling  of  multivariate  multinomial  responses  using  probit  model.  The estimated  parameters  were  calculated  using Maximum  Likelihood  Estimations  (MLE) based  on  the  GHK  simulation.  method  known  as Simulated  Maximum  Likelihood Estimations (SMLE). Likelihood function on the Probit model contains probability values that must be resolved by simulation. By using  the GHK simulation algorithm,  the estimator equation has been obtained for the parameters in the model Probit  Keywords : Probit Model, Newton-Raphson Iteration,  GHK simulator, MLE, simulated log-likelihood
Neural Network Model for Mathematic Scores Prediction: Case Study in SMK Negeri Pakis Aji, Jepara, Indonesia Adi Sucipto; Joko Minardi
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 1, ISSUE 1, February 2020
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol1.iss1.art5

Abstract

Aim of this research is to apply Neural Network Algorithm to predict score of mathematic in the national exam. During the time, the teacher only provided national exam materials and additional tryout tests without knowing how to predict the exam scores in mathematics subject. Data mining neural network algorithm obtained \Root Mean Square Error (RMSE) values which were used as basic improvement and clustering class By conducting research using data mining neural network algorithm, it proved that this model can be used to predict scores of Mathematics subject at SMK Negeri 1 Pakis Aji.. The result of this research by using data mining neural network algorithm found RMSE 0138 +/- 0.092. The lower the RMSE values the more accurate the neural network to predict mathematics scores of SMK Negeri 1 Pakis Aji.Received: 18 Agustus 2019; Accepted: 5 Januari 2020; Published: 14 January 2020
Senyawa Aktif Antiinflamasi dari Kulit Batang Pasak Bumi (Eurycoma longifolia Jack) Ari Widiyantoro; Indri Kusharyanti; Lia Destiarti; Elvi Rusmiyanto Pancaning Wardoyo
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 12, ISSUE 2, August 2011
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

Pasak bumi (Eurycoma longifolia Jack) merupakan salah satu famili Simaroubaceae yang mengandung senyawa kimia dengan aktivitas biologik yang potensial.Penggunaannya di masyarakat selama ini hanya terbatas sebagai aprodisiaka, namun beberapa penelitian menunjukkan ditemukannya senyawa kimia dengan aktivitas sebagai antimalaria, antikanker dan antioksidan. Penelitian ini mengungkapkan adanya senyawa kimia yang bersifat antiinflamasi dengan tinjauan reduksi radang pada kaki tikus yang terinduksi karagenan. Hasil penelitian diperoleh suatu senyawa quassinoid yang bersifat antiinflamasi yaitu eurycomaosida, namun aktivitasnya lebih rendah dibanding indometasin sebagai kontrol positif.   Kata Kunci : Eurycoma longifolia Jack, antiinflamasi, udema, karagenan, quassinoid

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