Judul: Satisfaction Levels of IPB Undergraduate Students towards Online Learning Services during the Pandemic Covid-19
Abstrak: Pandemi Covid-19 menyebabkan proses belajar mengajar di seluruh lembaga pendidikan harus diubah metodenya menjadi daring. Institut Pertanian Bogor (IPB) merupakan salah satu universitas yang ikut menerapkan pembelajaran daring terhitung dari bulan Maret 2020. Penelitian ini dilakukan dengan tujuan untuk menganalisis tingkat kepuasan mahasiswa S-1 IPB terhadap layanan pembelajaran daring selama pandemi Covid-19. Responden pada penelitian ini dipilih dengan menggunakan teknik voluntary sampling dengan jumlah responden sebanyak 255 responden. Data dikumpulkan melalui kuesioner online menggunakan google form. Data yang diperoleh diolah menggunakan microsoft excel, SPSS versi 25, dan SMART-PLS 3. Hasil analisis uji pengaruh menunjukkan kualitas layanan berpengaruh positif signifikan terhadap kepuasan konsumen, dan kepuasan konsumen berpengaruh positif signifikan terhadap net benefit. Saran yang bisa diberikan adalah IPB, dosen, hingga tendik departemen perlu mempertahankan dan meningkatkan kualitas pelayanan pembelajaran daring dari berbagai aspek., The Covid-19 pandemic has led to changes to the learning system online in all educational institutions. IPB University is one of the universities that implements online learning starting in March 2020. This research was conducted with the aim of analyze the level of satisfaction of IPB undergraduate students with online learning services during the Pandemic Covid-19. Respondents in this research were selected by voluntary sampling technique with 255 respondents. Data was collected through an online questionnaire using google form. The data obtained were processed using Microsoft Excel, SPSS version 25, and SMART-PLS 3. The results of the test analysis show that service quality has a significant positive effect on customer satisfaction, and also show that consumer satisfaction has a significant positive effect on the net benefit. Suggestions that can be given are that IPB, lecturers, and departments need to maintain and improve the quality of online learning services from various aspects.
Keyword: Kualitas layanan, Pembelajaran daring, Kepuasan, E-learning, satisfaction, service quality

Judul: Analysis of Student Satisfaction towards Online Food Delivery Services during COVID-19 Pandemic
Abstrak: Pelaku bisnis di Indonesia mulai menjadikan internet sebagai alat penunjang kegiatan bisnis mereka karena dapat mempermudah hubungan bisnis dengan pelanggan secara lebih luas dan efisien. Selama kondisi pandemi COVID- 19, ada peningkatan aktivitas jual beli yang dilakukan secara daring dan menjalankan prinsip pengantaran, terutama untuk sektor restoran. Penelitian ini bertujuan untuk mengetahui tingkat kepuasan dalam dua perusahaan yang menyediakan layanan jasa antar makanan. Penelitian ini menggunakan data primer dari 108 responden mahasiswa IPB yang melakukan pembelian secara daring. Metode analisis yang digunakan adalah analisis deskriptif, importance performance analysis (IPA), dan customer satisfaction index (CSI). Hasil penelitian menunjukkan bahwa tingkat kepuasan pada jasa pesan antar makanan secara daring diantaranya disebabkan oleh pelayanan yang diberikan oleh driver. Berdasarkan hasil analisis metode IPA, perusahaan penyedia layanan jasa pesan antar makanan perlu meningkatkan kinerja pada atribut-atribut yang memiliki tingkat kepentingan tinggi namun tingkat kinerjanya rendah, diantaranya atribut harga yang lebih rendah, lokasi dan harga promo., Businesses in Indonesia are starting to use the internet as a tool to support their business activities because it can facilitate business relations with customers more broadly and efficiently. During the COVID-19 pandemic, there has been an increase in online buying and selling activities and implementing the principle of delivery, especially for the restaurant sector and the food business, where orders can be made boldly. This study aims to determine the level of satisfaction in the two companies that provide food delivery services. This study used primary data from 108 IPB student respondents who made bold purchases. The analysis method used were descriptive analysis, importance performance analysis (IPA), and customer satisfaction index (CSI). The results showed that the level of satisfaction in the two companies was due to the services provided by the driver. Based on the results of the analysis of the important performance analysis method (IPA), food delivery service companies that can improve performance on attributes that have a high level of importance but have low levels of performance, include lower price attributes, location and promo prices.
Keyword: consumer satisfaction, COVID-19, food products, online shopping

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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