Judul: Analysis of Consumer Satisfaction on the Perfomance of Angkringan Mukti Kebumen Attributes during the Covid-19 Pandemic
Abstrak: Angkringan Mukti Kebumen hadir di tengah perubahan kebiasaan baru makan di luar rumah sehingga memicu terjadinya pertumbuhan jasa penyediaan makanan dan minuman termasuk di Kebumen. Kondisi tersebut mempertinggi persaingan antar jasa penyediaan makanan dan minuman ditambah lagi dengan munculnya pesaing sejenis yaitu angkringan yang mengusung konsep kekinian serta wabah Covid-19 yang masih terjadi. Penelitian ini bertujuan untuk mengetahui karakteristik konsumen, proses keputusan pembelian konsumen serta tingkat kepuasan konsumen Angkringan Mukti Kebumen pada masa pandemi Covid-19. Responden dalam penelitian ini sebanyak 141 orang yang ditentukan dengan metode non probability sampling melalui convinience sampling. Karakteristik konsumen dan proses keputusan pembelian diketahui melalui analisis kualitatif yaitu analisis deskriptif. Analisis kuantitatif ditentukan dengan Importance Perfomance Analysis (IPA) untuk mengetahui tingkat kepentingan dan kinerja suatu atribut dan Customer Satisfaction Index (CSI) untuk mengukur tingkat kepuasan yang dirasakan konsumen. Meskipun tidak ditemukan atribut dengan prioritas utama untuk diperbaiki pada pengelompokkan diagram kartesius IPA, pengelola perlu mempertimbangkan atribut pada kuadran III. Hasil perhitungan CSI menunjukkan tingkat kepuasan konsumen Angkringan Mukti Kebumen tergolong dalam kategori puas dengan nilai CSI sebesar 79,79 persen. Pengelola angkringan sebaiknya memperbaiki kinerja atribut yang rendah serta mempertahankan kualitas layanan agar dapat tercapai tingkat kepuasan yang maksimal., Angkringan Mukti Kebumen comes in the midst of new habit changes by eating outside the home, thus triggering the growth of food and beverage supply services including in Kebumen. This condition increases the competition of inter-food and beverage provision services exacerbated by the emergence of similar competitors, namely angkringan that carries the current concept and the Covid-19 pandemic that is still occurs. This research aims to find out characteristics of consumer, the process of purchasing consumers and the level of consumer satisfaction of Angkringan Mukti Kebumen during the Covid-19 pandemic. The number of respondents is 141 people determined by the non-probability sampling method through convenience sampling. The characteristics of consumers and the buying decision process are known through qualitative analysis that is descriptive analysis. Quantitative analysis determined by Importance Performance Analysis (IPA) to determine the level of importance and performance of an attribute and the Customer Satisfaction Index (CSI) to measure the level of satisfaction felt by consumers. Although no attributes with the main priority were found to be corrected in the grouping of cartesius IPA diagrams, the manager needs to consider the attributes in quadrant III. The results of the CSI calculation showed the level of consumer satisfaction of Angkringan Mukti Kebumen belonged to the category of satisfied with a CSI value of 79.79 percent. Angkringan managers should improve the performance of low attributes and maintain service quality in order to achieve the maximum level of satisfaction.
Keyword: CSI, IPA, Kinerja atribut, Persaingan, Tingkat kepuasan

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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