Judul: Efficiency of Financial Performance of  BAZNAS, Rumah Zakat, and Inisiatif Zakat Indonesia During the Covid-19 Pandemi
Abstrak: Pandemi Covid-19 menyebabkan sektor ekonomi Indonesia terkena dampaknya. Dalam upaya pemulihan sektor ekonomi, Indonesia sebagai negara yang memiliki mayoritas penduduk muslim dapat memaksimalkan dana zakat, infak, dan sedekah (ZIS) melalui Organisasi Pengelola Zakat (OPZ). Penelitian ini bertujuan untuk menganalisis tingkat efisiensi BAZNAS, Rumah Zakat dan Inisiatif Zakat Indonesia selama pandemi Covid-19 dan mengetahui perbedaan tingkat efisiensi sebelum dan saat pandemi Covid-19. Penelitian ini terdiri dari dua tahap, tahap yang pertama yaitu pengukuran efisiensi menggunakan Data Envelopment Analysis (DEA). Tahap kedua menggunakan uji beda untuk mengetahui perbedaan tingkat efisiensi sebelum dan saat pandemi Covid-19. Hasil penelitian pada tahap pertama menunjukan bahwa sebelum pandemi LAZ Rumah Zakat tahun 2018 dan BAZNAS 2019 mengalami inefisiensi. Sedangkan saat pandemi LAZ Inisiatif Zakat Indonesia 2020 dan BAZNAS 2021 juga mengalami inefisiensi. Selanjutnya, tahap kedua uji beda menunjukan bahwa tidak ada perbedaan yang signifikan antara nilai efisiensi sebelum pandemi dan saat pandemi Covid-19., The Covid-19 pandemic has affected the Indonesian economic sector. In an effort to restore the economic sector, Indonesia as a country with a majority Muslim population can maximize zakat, infaq, and alms funds (ZIS) through the Zakat Management Organization (OPZ). This study aims to analyze the level of efficiency of BAZNAS, Rumah Zakat and Inisiatif Zakat Indonesia during the Covid-19 pandemi and find out the differences in efficiency levels before and during the Covid-19 pandemi. This research consists of two stages, the first stage is efficiency measurement using Data Envelopment Analysis (DEA). The second stage uses a different test to find out the difference in efficiency levels before and during the Covid-19 pandemi. The results of the research in the first stage show that before the pandemi LAZ Rumah Zakat in 2018 and BAZNAS 2019 experienced inefficiencies. Meanwhile, during the LAZ pandemi, the 2020 Indonesian Zakat Initiative and BAZNAS 2021 also experienced inefficiencies. Furthermore, the second stage of the different tests showed that there was no significant difference between the efficiency values before the pandemi and during the Covid-19 pandemi
Keyword: DEA, Difference Test, Efficiency, OPZ

Judul: Efficiency Analysis of Zakat Fund Management by the National Amil Zakat Agency (BAZNAS)
Abstrak: BAZNAS adalah lembaga yang berwenang untuk mengelola dana zakat sebagai pengentas kemiskinan. Perolehan dana zakat terus bertumbuh seiring tahun, tetapi tidak diiringi dengan penurunan tingkat kemiskinan yang signifikan. Penelitian ini bertujuan untuk menganalisis efisiensi BAZNAS dalam mengelola dana zakat. Metode yang digunakan dalam penelitian adalah DEA dengan pendekatan produksi dan intermedasi. Data penelitian menggunakan laporan keuangan tahunan BAZNAS RI periode 2013-2022. Hasil penelitian menunjukkan bahwa BAZNAS RI kurang efisien dalam mengelola dana zakat dengan pendekatan produksi pada tahun 2013, 2016, dan 2017. Sedangkan pada pendekatan intermediasi, BAZNAS RI sudah efisien pada seluruh periode yang diteliti., BAZNAS is an institution authorized to manage zakat funds as a poverty alleviator. The acquisition of zakat funds continues to grow over the years, but it is not accompanied by a significant reduction in poverty levels. This study aims to analyze the efficiency of BAZNAS in managing zakat funds. The method used in this research is DEA with production and intermediation approach. The data used in this research is annual financial report of BAZNAS RI from 2013 to 2022. The results showed that BAZNAS RI was less efficient in managing zakat funds with the production approach in 2013, 2016, and 2017. While in the intermediation approach, BAZNAS RI has been efficient in all periods studied.
Keyword: efisiensi, produksi, DEA, Intermediasi, zakat

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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