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: Customer Attitude and Satisfaction by Online Application for Ready-to-Eat Food Delivery Service in Jabodetabek
Abstrak: Pandemi Covid-19 membuat masyarakat harus lebih berusaha untuk bertahan hidup. Khususnya warga sekitar Jabodetabek yang terdampak PSBB mengakibatkan mobilisasi masyarakat menjadi terbatas dan aplikasi daring membantu pelanggan untuk membeli makanan. Tujuan dari penelitian ini adalah menganalisis proses keputusan pembelian, sikap dan kepuasan pelanggan serta menguji perbedaan secara nyata pada sikap dan kepuasan pelanggan. Analisis deskriptif digunakan untuk proses keputusan pembelian pelanggan. Analisis Multiatribut Fishbein digunakan untuk menganalisis sikap pelanggan dan kepuasan pelanggan pada penelitian ini menggunakan analisis CSI. Serta penggunaan uji beda nonparametik Mann-Whitney. Hasil penelitian menunjukkan bahwa terdapat lima proses keputusan pembelian, nilai sikap terhadap pelanggan aplikasi GrabFood lebih besar dibandingkan GoFood dengan poin 193,88 dan 193,86. Diperoleh sikap dan kepuasan pelanggan GoFood dan GrabFood tidak berbeda secara nyata, serta pelanggan dianggap puas dengan nilai CSI GoFood dan GrabFood sebesar 79,24% dan 78,16%., The Covid-19 pandemic has forced people to do more to survive. In particular, residents around Jabodetabek who were affected by the PSBB resulted in limited community mobilization and online applications helping customers to buy food. The purpose of this study are to analyze the purchasing decision process, attitudes and customer satisfaction and to test whether there is a significant difference in attitudes and customer satisfaction. Descriptive analysis tools are used for the customer's purchasing decision process. Fishbein Multiattribute Analysis is used to analyze customer attitudes and customer satisfaction in this study using CSI analysis. And the use of the Mann-Whitney nonparametric difference test. The results show that there are five purchasing decision processes, the attitude value towards GrabFood application customers is greater than GoFood with 193.88 and 193.86 points. The attitudes and satisfaction of GoFood and GrabFood customers were not significantly different, and customers were considered satisfied with the CSI GoFood and GrabFood values of 79.24% and 78.16%, respectively.
Keyword: Customer Satisfaction Index, Mann-Whitney, Online Application, Fishbein Multi-attribute

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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