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UPAYA MENYISIPKAN PESAN MORAL DALAM MATERI STATISTIKA Subekti, Retno
AdMathEdu : Mathematics Education, Mathematics, and Applied Mathematics Journal Vol 5, No 2: Desember 2015
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (149.354 KB) | DOI: 10.12928/admathedu.v5i2.4772

Abstract

Analisis Data Multivariat Dengan Program R Wustqa, Dhoriva Urwatul; Listyani, Endang; Subekti, Retno; Kusumawati, Rosita; Susanti, Mathilda; Kismiantini, Kismiantini
Jurnal Pengabdian Masyarakat MIPA dan Pendidikan MIPA Vol 2, No 2 (2018): Vol 2, No 2 (2018)
Publisher : Yogyakarta State University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (277.982 KB) | DOI: 10.21831/jpmmp.v2i2.21913

Abstract

Analisis multivariat adalah salah satu teknik dalam statistika yang digunakan untuk menganalisis secara simultan variabel lebih dari satu. Perhitungan dalam analisis data multivariat lebih kompleks dibandingkan dengan analisis univariat, sehingga penggunaan program statistika akan mempermudah dalam analisis.  Salah satu program statistika yang dapat diperoleh secara gratis (tanpa lisensi) adalah program R. Workshop program R untuk analisis data multivariat bagi para lulusan S1 Pendidikan Matematika/Matematika dan mahasiswa program pasca sarjana Pendidikan Matematika secara umum bertujuan untuk memberikan pengetahuan dan ketrampilan dasar penggunaan program R pada analisis data multivariat. Metode yang digunakan dalam pelatihan meliputi tutorial dan praktek secara langsung. Sebagian peserta belum pernah menggunakan program R, dan terlihat bahwa mereka antusias dalam mengikuti pelatihan. Berdasarkan pengamatan dan tanya jawab dengan peserta pelatihan, tampak bahwa peserta bersemangat mengikuti kegiatan pelatihan. Dengan pelatihan ini para peserta mendapat pengetahuan secara teoritis tentang analisis komponen utama, analisis faktor dan secara praktek meliputi ketrampilan tentang bagaimana menganalisis data multivariat dengan program R, dan menginterpretasikan hasil analisis dengan kedua metode tersebut. Kata kunci: analisis multivariat, program statistika R. Multivariate Data Analysis Using R Program Abstract           Multivariate analysis is a technique in statistics that is used to simultaneously analyze more than one variable. Dealing with multivariate data analysis calculations are more complex than the univariate analysis, so the use of statistical program will make it easier. One of the free statistical programs (free license) is R program. Workshop R program on the multivariate data analysis for people who had mathematics or mathematics education degree or graduate students in general aims to provide multivariate data analysis skills using statistics R program. The training methods were tutorial and practices in class. Some participants had never used the R program prior to the training, and they were enthusiastic during training. According to the observations and questions and answers session, the participants appeared to have passions on learning the usage of  the statistical R program on analyzing multivariate data. From the training, the participants gained theoretical knowledge about the principal component analysis, factors analysis, and practices about the skills on how to analyze mulivariate data, and interpret the results of the analysis with both methods using the  R program. Keywords: multivariat analysis, R statistical program
APLIKASI REGRESI PARTIAL LEAST SQUARE UNTUK ANALISIS HUBUNGAN FAKTOR-FAKTOR YANG MEMPENGARUHI INDEKS PEMBANGUNAN MANUSIA DI KOTA YOGYAKARTA Masruroh, Marwah; Subekti, Retno
MEDIA STATISTIKA Vol 9, No 2 (2016): Media Statistika
Publisher : Department of Statistics, Faculty of Science and Mathematics, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (169.248 KB) | DOI: 10.14710/medstat.9.2.75-84

Abstract

Human Development Index is one of the indicators to measure the success of a region in the field of human development sector. There are several factors that affect Human Development Index, such as life expentancy, the literacy rate, the average length of the school, and the index of purchasing power. The aim in this paper is to analyze the relationship between factors that affect Human Development Index in Yogyakarta using regression analysis. One of the assumptions of classical regression is not going multicollinierity. Multicollinierity cause misinterpretation of regression coefficients with Ordinary Least Square (OLS) method. One method used to overcome multicollinierity is Partial Least Square (PLS). The result of Human Development Index data analysis showed there was a high correlation between the predictor variables or in other words going multicollinierity, so using PLS method, we obtained adjusted R2 of 99.3% Human Development Index variables can be explained by the four predictor variables. By using PLS method, multicollinierity resolved in the problem of violation in the linear regression assumption. Keywords: IPM, OLS, regression, PLS.
PARTIAL LEAST SQUARES (PLS) GENERALIZED LINEAR DALAM REGRESI LOGISTIK Retno Subekti
PYTHAGORAS Jurnal Pendidikan Matematika Vol 5, No 2: Desember 2009
Publisher : Department of Mathematics Education, Faculty of Mathematics and Natural Sciences, UNY

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (196.948 KB) | DOI: 10.21831/pg.v5i2.549

Abstract

Kasus multikolinieritas seringkali dijumpai dalam regresi yang mengakibatkan salah interpretasi model regresi yang terbentuk. Seperti halnya dalam regresi linear, dalam regresi logistik kasus multikolinearitas juga dapat menjadi masalah, karena adanya korelasi yang cukup tinggi antara variabel prediktornya. Sehingga untuk mengatasi masalah seperti ini, akan digambarkan aplikasi prosedur partial least squares terhadap suatu kasus regresi logistik khususnya dalam contoh kasus makalah ini adalah regresi logistik ordinal. Kata kunci : Partial Least Square generalized linier , multikolinieritas, regresi logistik
A Study of Partial Least Squares (Case Study: Cox-PLS Regression) Retno Subekti; Rosita Kusumawati
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (160.247 KB) | DOI: 10.21831/jsd.v3i1.2792

Abstract

Indication of multicollinearity in regression analysis will lead to wrong interpretation when interpreting the results. One of the handling of the case of multicollinearity is to use of PLS (partial least squares). The purpose of this study is to provide a general overview of PLS. The results of this study are in general PLS study along both the concept and the classification methodology and its application. PLS is generally divided into two branches, namely PLS regression and path analysis. In the application of PLS, the data used TB patient survival (tubercolosis) in Yogyakarta, which is obtained from a private hospital in Yogyakarta. The data were analyzed using Cox regression, but there is multicollinearity so then there is an error in the interpretation of the significance of the model. By using PLS-Cox regression, we obtained one PLS component consisting of one independent variable, namely class care.   Key words: PLS regression, PLS path modelling, Cox regression
Peramalan Harga Saham Berdasarkan Jaringan Syaraf Fuzzy Elman Recurrent dengan Optimasi Evolutif Rosita Kusumawati; Dhoriva Urwatul Wutsqa; Retno Subekti
Jurnal Sains Dasar Vol 7, No 2 (2018): October 2018
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/jsd.v7i2.38548

Abstract

Analisis runtun waktu telah banyak digunakan untuk menentukan harga saham masa depan. Analisis dan pemodelan runtun waktu keuangan merupakan tugas penting untuk membantu investor dalam mengambil keputusan. Meskipun demikian, prediksi harga dengan menggunakan runtun waktu tidak sederhana dan memerlukan analisa yang mendalam. Selain itu, di lingkungan yang dinamis seperti pasar saham, non linieritas dari runtun waktu adalah karakteristik yang diucapkan, dan ini segera mempengaruhi keefektifan ramalan harga saham. Dengan demikian, makalah ini bertujuan untuk mengusulkan sebuah metodologi yang meramalkan harga saham bulanan perusahaan Indonesia, yang diperdagangkan di Bursa Efek Jakarta. Kami mengusulkan jaringan syaraf Fuzzy Elman Recurrent untuk meramalkan harga saham dan algoritma genetika untuk mengoptimalkan bobot model. Prediksi kinerja dievaluasi dengan menggunakan perhitungan Mean Absolute Persentase Persentase (MAPE). Makalah ini menyimpulkan bahwa metode yang diusulkan mengoptimalkan peramalan harga.
UPAYA MENYISIPKAN PESAN MORAL DALAM MATERI STATISTIKA Retno Subekti
AdMathEdu : Jurnal Ilmiah Pendidikan Matematika, Ilmu Matematika dan Matematika Terapan Vol 5, No 2: Desember 2015
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (149.354 KB) | DOI: 10.12928/admathedu.v5i2.4772

Abstract

Penerapan Metode GARCH-Vine Copula untuk Estimasi Value at Risk (VaR) pada Portofolio Herida Okta Pintari; Retno Subekti
Jurnal Fourier Vol. 7 No. 2 (2018)
Publisher : Program Studi Matematika Fakultas Sains dan Teknologi UIN Sunan Kalijaga Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (384.026 KB) | DOI: 10.14421/fourier.2018.72.63-77

Abstract

Salah satu alat ukur yang digunakan untuk menghitung risiko portofolio adalah Value at Risk (VaR). Beberapa metode pengukuran VaR mengasumsikan return berdistribusi normal dan ukuran dependensi antar saham menggunakan korelasi linear. Faktanya, asumsi normalitas pada data finansial jarang terpenuhi dan terdapat indikasi adanya heteroskedastisitas. Selain itu, kebergantungan antar saham yang non-linear tidak sesuai apabila diukur dengan korelasi linear. Penyimpangan ini menyebabkan tidak validnya estimasi VaR. Tujuan dari penelitian ini adalah untuk mengetahui penerapan metode GARCH-Vine Copula untuk estimasi VaR pada portofolio. Vine Copula adalah fungsi distribusi multivariat yang menggabungkan distribusi marginal return univariat dalam portofolio, dan dapat menggambarkan struktur kebergantungan non-linearnya. Vine Copula dapat dilakukan dengan menentukan dekomposisi Vine Copula dan fungsi keluarga copulanya. Dekomposisi Vine Copula dilakukan dengan menggunakan C-Vine dan D-Vine Copula. Kemudian dengan menggunakan fungsi copula keluarga Archimedean, yaitu Clayton, Gumbel, dan Frank dapat ditentukan distribusi bersamanya. Pembentukan distribusi marginal menggunakan model GARCH berdistribusi Student-t digunakan untuk mengatasi adanya heteroskedastisitas. Hasil penerapan dari tiga saham perbankan, yaitu BBNI, BBRI, dan BMRI periode 26 Agustus 2013 hingga 20 November 2017 diperoleh model D-Vine Copula dengan fungsi copula Frank adalah model terbaik untuk memodelkan data, dengan nilai VaR sebesar 1,86%, 2,56%, dan 4,49% dari dana investasi pada tingkat kepercayaan 90%, 95%, dan 99%. [One of the measurement instrument that are used to calculate the risk of portfolio is Value at Risk (VaR). Several methods of measuring VaR assumes normal and the size of dependencies return between the stock using a linear correlation. Basically, the assumption normal in financial data is violated and the possibility of heteroscedasticity is indicated. In addition, dependences non-linear is not appropriate when measured with a linear correlation. This deviation causes invalidity VaR estimation. The purpose of this research is to know the application of GARCH-Vine Copula method for estimation of VaR on portfolio. Vine Copula is a multivariate distribution function that combines the univariate marginal distribution of return in portfolio, and it can describe the structure of dependencies non-linear. Vine Copula can be done by determining the decomposition of Vine Copula and its copula family function. Vine Copula decomposition is using C-Vine and D-Vine Copula. Then by using the copula function of the Archimedean family, namely Clayton, Gumbel, and Frank can be determined the joint distribution. The facts, the formation of the marginal distribution of GARCH model using the student-t distribution used to overcome the presence of heteroscedasticity. The result of the application of these stocks namely BBNI, BBRI, and BMRI from 26 August 2013 to 20 November 2017 has shown model D-Vine Copula copula functions with Frank is the best one to model the data. So, the VaR estimation at 90%, 95%, and 99% confidence levels are 1,86%, 2,56%, and 4,49% respectively of the invested funds.]
CAN ZAKAT AND PURIFICATION BE EMPLOYED IN PORTFOLIO MODELLING? Retno Subekti; Abdurakhman Abdurakhman; Dedi Rosadi
Journal of Islamic Monetary Economics and Finance Vol 8 (2022): Special Issue: Islamic Social Finance
Publisher : Bank Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21098/jimf.v8i0.1418

Abstract

The Capital Asset Pricing Model (CAPM), which has interest rates in its specification, can be deemed non-Shariah compliant. Therefore, the sukuk rate has been proposed to replace these rates in CAPM. This study analyses portfolio modelling by involving two essential elements in Islamic principles, namely zakat and purification. The concept of purification has been applied in the Shariah stock selection process in Indonesia, while at the same time, zakat has been widely socialised in stock investment. The study highlights two models that consider the concept of zakat reduction and the purification factors for portfolios in the Indonesian stock market. According to the robustness tests conducted, the proposed Shariah-compliant asset pricing model developed in this study is valid. Zakat reduction and purification factor integration in mathematical models can be applied in portfolio modelling.
ESTIMASI CONDITIONAL VALUE AT RISK (CVaR) PADA PORTOFOLIO MENGGUNAKAN COPULA BERSYARAT Intan Lisnawati , Retno Subekti
Jurnal Kajian dan Terapan Matematika Vol 7, No 3 (2018): Jurnal Matematika
Publisher : Jurnal Kajian dan Terapan Matematika

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

AbstrakRisiko dapat diartikan sebagai tingkat kerugian yang dapat dialami investor dalam berinvestasi. Conditional Value at Risk (CVaR) merupakan salah satu metode untuk mengestimasi risiko. Penelitian ini bertujuan untuk mengetahui prosedur estimasi CVaR pada portofolio menggunakan copula bersyarat. Metode yang digunakan untuk mengestimasi CVaR dalam penelitian ini adalah menggunakan fungsi distribusi copula bersyarat Clayton. Copula bersyarat adalah copula yang menerapkan koefisien dependensi ekor berdasarkan karakteristik dari masing-masing copula bersyarat yang digunakan. Salah satu copula bersyarat adalah copula Clayton dari kelas Archimedian. Dalam membentuk fungsi distribusi marginal dari saham digunakan model ARCH/GARCH sebagai metode yang dapat memodelkan data dengan variansi yang tidak homogen. Hasil penelitian adalah prosedur estimasi CVaR pada portofolio menggunakan copula bersyarat yaitu: perhitungan return saham, identifikasi karakteristik data, pemodelan distribusi marginal dengan GARCH, pembentukan fungsi distribusi bersama dengan copula bersyarat Clayton, dan perhitungan CVaR. Kata kunci: Portofolio, Copula Bersyarat, CVaR AbstractRisk can be interpreted as the level of loss that can be experienced by investors in investing. CVaR is one method to estimate risk. Conditional copula is a copula that implements tail dependent coefficients based on the characteristics of each conditional copula used. One of the conditional copulas is Clayton's copula from the Archimedian class. This study aims to find out the CVaR estimation procedure on the portfolio using conditional copula. The method used to estimate CVaR in this study is to use Clayton's conditional copula distribution function. The stock marginal distribution is modeled by ARCH / GARCH because stock data has a non-homogeneous variance. The result of this research is CVaR estimation procedure on portfolio using conditional copula, those are: stock return calculation, identification of data characteristic, modeling of marginal distribution with GARCH, establishment of distribution function along with Clayton conditional copula, and CVaR calculation. Keywords: Portfolio, Conditional Copula, CVaR