Judul: Analisis Efisiensi BPRS di Wilayah Jabodetabek Periode Sebelum dan Selama Pandemi COVID-19
Abstrak: Kinerja Bank Pembiayan Rakyat Syariah (BPRS) di Indonesia mengalami perkembangan yang fluktuatif, termasuk BPRS yang berada di wilayah Jakarta, Bogor, Depok, Tangerang dan Bekasi (Jabodetabek). Terjadinya perubahan kinerja BPRS serta pandemi COVID-19 masuk di Indonesia menyebabkan perlu adanya pengukuran kinerja BPRS. Penelitian ini bertujuan untuk menganalisis tingkat efisiensi BPRS di Jabodetabek dan membandingkan rata-rata nilai efisiensi BPRS sebelum dan selama pandemi COVID-19. Sampel yang digunakan adalah 11 BPRS di Jabodetabek. Metode analisis yang digunakan adalah analisis deskriptif dan analisis kuantitatif. Metode kuantitatif yang digunakan pada penelitian ini adalah Data Envelopment Analysis (DEA). Besarnya nilai standar deviasi dari output yang digunakan menunjukkan bahwa tedapat perbedaan yang cukup besar dalam jumlah output yang dihasilkan BPRS. Hasil penelitian dengan DEA terdapat 10 Decision Making Unit (DMU) memiliki skor efisiensi sebesar 100 persen sebelum pandemi dan 9 DMU selama pandemi. Pada uji Mann-Whitney menunjukkan bahwa tidak terdapat perbedaan rata-rata nilai efisiensi sebelum dan selama pademi COVID-19. Kata, The performance of Islamic Rural Banks (BPRS) in Indonesia has fluctuated, including BPRS in Jakarta, Bogor, Depok, Tangerang, and Bekasi (Jabodetabek).The purpose of this study is to assess BPRS efficiency in Jabodetabek and compare BPRS efficiency before and during the COVID-19 pandemic. In Jabodetabek, 11 BPRS were used as a sample. The analytical methods used are descriptive analysis and quantitative analysis. Data Envelopment Analysis was the quantitative method used in this study (DEA). The magnitude of the standard deviation of the output used indicates that there is a significant difference in the amount of output produced by the BPRS. According to the findings of the DEA study, 10 Decision Making Units (DMU) had an efficiency score of 100 percent before the pandemic and 9 DMU during the pandemic. According to the Mann-Whitney test, there is no difference in the average efficiency value before and after the COVID-19 pandemic.
Keyword: BPRS, COVID-19 Pandemic, Data Envelopment Analysis, Efficiency, Mann-Whitney test

Judul: Analysis of Indonesian Islamic Rural Banks Efficiency Before and During Covid-19 Pandemic: Two-Stage Approach
Abstrak: Bank Pembiayaan Rakyat Syariah (BPRS) sebagai lembaga keuangan syariah yang memberikan pembiayaan kepada UMKM memiliki andil yang cukup besar pada perekonomian Indonesia. Namun, pada saat pandemi Covid-19 pemerintah mengeluarkan insentif pembiayaan bagi UMKM, yang mengakibatkan berkurangnya potensi BPRS di Indonesia dalam menyalurkan pembiayaan. Penelitian ini bertujuan untuk menganalisis efisiensi BPRS di Indonesia secara agregat, sebelum dan selama pandemi Covid-19 periode 2018-2022. Jumlah sampel sebanyak 60 menggunakan metode two-stage approach, di mana pada tahap pertama dilakukan pengukuran efisiensi BPRS menggunakan metode DEA, kemudian tahap kedua dianalisis faktor apa saja yang memengaruhi efisiensi kinerja BPRS memakai metode regresi Tobit. Hasil dari penelitian ini menunjukkan rata-rata BPRS lebih efisien pada periode sebelum pandemi Covid-19. Faktor internal yang memengaruhi efisiensi adalah CAR, ROA, dan FDR secara signifikan positif serta BOPO secara signifikan negatif. Sedangkan faktor eksternal yang memengaruhi efisiensi adalah GDP secara signifikan negatif. Penelitian selanjutnya diharapkan menambah rentang waktu, serta menggunakan pembagian zona berdasarkan tier agar hasil yang didapatkan lebih akurat., Islamic Rural Bank (BPRS) as share financial institutions that provided financing to MSMEs have a sizeable contribution to the Indonesian economy. However, during the Covid-19 pandemic, the government issued financing incentives for MSMEs, which resulted reduction on the potential of BPRS in Indonesia on financing distribution. This study analyzes the efficiency of BPRS in Indonesia aggregately, before and during Covid-19 pandemic on 2018-2022 period. This study aims to analyze the efficiency of BPRS in Indonesia in aggregate, before and during the Covid-19 pandemic for the 2018-2022 period. With a total of 60 samples, a two-stage approach method was used, where in the first stage BPRS efficiency measurements were carried out using the DEA method, then the second stage was analyzed what factors affected the efficiency of BPRS performance using Tobit regression. The results of this study show that on average, BPRS was more efficient in the period before the Covid-19 pandemic. Internal factors that affected efficiency were CAR, ROA, and FDR significantly positive and BOPO significantly negative. While the external factor that affected efficiency was GDP significantly negative. Further research is expected to increase the time span, and use the division of zones by tier so that the results obtained are more accurate.
Keyword: Islamic rural bank, Covid-19, Effiency, MSMEs

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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