Judul: Identifikasi Peubah yang Berpengaruh terhadap Kejadian Rawan  Pangan di Jawa Barat dengan Generalized Linear Mixed Model  LASSO
Abstrak: Kerawanan pangan adalah kondisi ketidakmampuan individu atau kelompok di suatu daerah untuk memperoleh pangan yang cukup dan layak untuk hidup sehat dan aktif. Pengentasan kerawanan pangan sejalan dengan tujuan pembangunan berkelanjutan, terutama tujuan kedua, tanpa kelaparan. Sehingga diperlukan kajian terkait kerawanan pangan seperti mengidentifikasi faktor-faktor yang berpengaruh terhadap kejadian rawan pangan. Penelitian ini bertujuan untuk mengidentifikasi variabel-variabel yang mempengaruhi kejadian kerawanan pangan di Jawa Barat. Dengan menggunakan data Survei Sosial Ekonomi Nasional Provinsi Jawa Barat Tahun 2020. Data tersebut memiliki tipe variabel respon kategorik dan diambil menggunakan teknik two-stage sampling sehingga dapat dianalisis menggunakan metode Generalized Linear Mixed Model LASSO. Analisis menggunakan paket glmmLasso dengan 10-fold cross-validation (CV) pada 20 nilai lambda (16 hingga 35). CV dilakukan untuk mengukur kebaikan model dan akurasi, sehingga diperoleh lambda terbaik untuk membangun model terbaik untuk diinterpretasikan. Variabel yang secara umum berpengaruh signifikan terhadap kerawanan pangan di Jawa Barat adalah variabel X14 yang menunjukkan jumlah anggota rumah tangga yang memiliki tabungan yang berpengaruh negatif terhadap kejadian rawan pangan di Jawa Barat dan variabel X19 yang menunjukkan kepemilikan penerima bantuan iuran BPJS kesehatan yang berpengaruh positif terhadap kejadian rawan pangan di Jawa Barat., Food insecurity is a condition of the inability of an individual or group in an area to obtain sufficient and appropriate food for a healthy and active life. The alleviation of food insecurity is in line with the Sustainable Development Goals, especially the second goal, zero hunger. This study aims to identify the variables that influence the incidence of food insecurity in West Java. By using data from the National Socio-Economic Survey of West Java Province in 2020. The data has a categorical type of response variable and is taken using a two-stage sampling technique so that it can be analyzed using the Generalized Linear Mixed Model LASSO method. Analysis using the glmmLasso package with 10-fold cross-validation (CV) at 20 lambda values (16 to 35). CV is done to measure the goodness of the model and accuracy, so that the best lambda is obtained to build the best model to be interpreted. The variables that generally have a significant effect on food insecurity in West Java are the X14 variable that shows the number of household members who have savings which have a negative impact and X19 variable that shows the ownership of PBI BPJS which have a positive impact.
Keyword: classification, food insecurity, GLMM LASSO, variable selection

Judul: Variable Importance Analysis Based on The Extra-Trees Model for Identification of The Characterizing Variables of Food-Insecure Households in West Java
Abstrak: Sekitar 2,3 miliar orang di dunia mengalami kerawanan pangan. Kerawanan pangan dapat memiliki konsekuensi serius bagi kesehatan dan kesejahteraan. Pengentasan kerawanan pangan menjadi salah satu isu krusial dalam mewujudkan tujuan kedua pembangunan berkelanjutan, yaitu tanpa kelaparan. Penelitian ini bertujuan untuk mengidentifikasi peubah penting yang mencirikan kerawanan pangan rumah tangga di Jawa Barat. Penelitian akan dibagi menjadi dua subpopulasi yaitu rumah tangga perdesan dan perkotaan. Data yang digunakan dalam penelitian ini adalah data Survei Sosial Ekonomi Nasional tahun 2021. Algoritma yang digunakan untuk melakukan pemodelan klasifikasi kejadian rawan pangan adalah Extremely Randomized Trees (Extra-Trees) dengan penanganan data tidak seimbang menggunakan oversampling ADASYN dan pembobotan kelas peubah respon. Peubah penting yang mencirikan kerawanan pangan diidentifikasi menggunakan SHapley Additive exPlanations (SHAP). Model dengan penanganan menggunakan pembobotan kelas menghasilkan kinerja yang lebih baik dibanding tanpa penanganan dan dengan penanganan ketidakseimbangan data menggunakan ADASYN. Hasil evaluasi menunjukan balanced accuracy model perdesaan sebesar 60,76% dan model perkotaan sebesar 64,08%. Jenis lantai, kepemilikan aset tanah, Bantuan Pangan Non-Tunai (BPNT), bantuan Pemda, jenis dinding, banyaknya penabung, pendidikan KRT, Penerima Bantuan Iuran (PBI) BPJS, bahan bakar masak, dan jenis kelamin KRT merupakan peubah penting yang mencirikan kejadian rumah tangga rawan pangan perdesaan. Banyaknya penabung, PBI BPJS, kepemilikan aset tanah, jenis lantai, pendidikan KRT, BPNT, bantuan Pemda, Program Keluarga Harapan (PKH), sanitasi layak, dan jumlah perokok merupakan peubah penting yang mencirikan kejadian rumah tangga rawan pangan perkotaan., Approximately 2,3 billion people in the world have experienced food insecurity. Food insecurity can have serious consequences for health and well-being. Alleviation of food insecurity is one of the crucial issues in realizing the second goal of the Sustainable Development Goals, zero hunger. This study aims to identify important variables that characterize household food insecurity in West Java Province. This study will be divided into two subpopulations, rural and urban households. The data used in this study is the 2021 National Social and Economic Survey. The algorithm used to classify the incidence of household food insecurity is Extremely Randomized Trees (Extra-Trees) with imbalanced data handling using ADASYN and class weight of response variables. Important variables that characterize food insecurity are identified using SHapley Additive exPlanations (SHAP). Models that handle by using class weights produce better performance than without handling imbalanced data and with handling by using ADASYN. The evaluation results show that the balanced accuracy of the rural model is 60,76%, and the urban model is 64,08%. Floor type, land assets ownership, Non-Cash Food Assistance (BPNT), local government assistance, wall type, number of savers, education of household head, Premium Assistance Beneficiaries (PBI) BPJS, cooking fuel, and gender of household head are important variables that characterize the incidence of food insecurity in rural households. The number of savers, PBI BPJS, land assets ownership, floor type, education of household head, BPNT, local government assistance, Keluarga Harapan Program (PKH), decent sanitation, and number of smokers are important variables that characterize food insecurity in urban households.
Keyword: Extra-Trees, food insecurity, imbalanced data, SHAP, West Java

Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4