Judul: Pengaruh Mutu Produk, Harga dan Promosi terhadap Keputusan Pembelian Celana Jeans Merek Fallas di Fallas Fashion Tanah Abang
Abstrak: Pakaian merupakan kebutuhan primer bagi manusia yang harus dipenuhi. PT Fallasindo Utama Garmen merupakan perusahaan lokal di bidang industri pakaian jadi menyediakan produk celana jeans. Penelitian bertujuan menganalisis pengaruh dari mutu produk, harga dan promosi terhadap keputusan pembelian Celana Jeans Merek Fallas di Fallas Fashion Tanah Abang. Penelitian terdiri dari data primer dan sekunder. Data primer diperoleh melalui hasil wawancara dan kuesioner dari 103 responden dengan teknik pengambilan contoh purposive sampling. Data sekunder diperoleh dari studi literatur yang relevan. Alat analisis data adalah analisis regresi linear berganda. Hasil penelitian menunjukkan peubah mutu produk, harga dan promosi secara simultan berpengaruh terhadap keputusan pembelian. Secara parsial peubah mutu produk, harga dan promosi memiliki pengaruh nyata dan positif terhadap keputusan pembelian. Hal ini menunjukkan bahwa semua peubah dalam penelitian, yaitu mutu produk, harga dan promosi berpengaruh terhadap keputusan pembelian.
Keyword: Celana jeans Fallas, Harga, Keputusan pembelian, Mutu Produk, Promosi

Judul: The Effect of Perceived Product Quality and Price on Consumer Satisfaction towards Local Fashion Brand
Abstrak: Tren fesyen di Indonesia terus berkembang dengan pesat dalam beberapa tahun terakhir. Hal ini telah menciptakan lingkungan yang semakin kompetitif, sehingga merek global maupun lokal terus bersaing untuk memenuhi kebutuhan masyarakat. Penelitian ini bertujuan untuk menganalisis pengaruh persepsi kualitas produk dan persepsi harga terhadap kepuasan konsumen produk fesyen lokal merek X. Desain penelitian ini adalah cross-sectional study dengan teknik purposive sampling. Pengumpulan data dilakukan secara offline dengan teknik accidental sampling menggunakan kuesioner kepada 182 responden. Data diolah dan dianalisis menggunakan Statistical Package for Social Science (SPSS) dan Partial Least Squares Structural Equation Modeling (PLS-SEM). Hasil menunjukkan tidak terdapat hubungan antara karakteristik responden dengan persepsi kualitas produk, persepsi harga, dan kepuasan konsumen. Persepsi kualitas produk berpengaruh positif signifikan terhadap persepsi harga dan kepuasan konsumen. Persepsi harga juga ditemukan berpengaruh positif signifikan terhadap kepuasan konsumen., Fashion trends in Indonesia have continued to grow rapidly in recent years. This has created an increasingly competitive environment, where local and global brands compete to meet people's needs. This research aims to analyze the effect of perceived product quality and price perception on consumer satisfaction towards local fashion product from brand X. The research design is a cross-sectional study with a purposive sampling technique. Data collection was conducted offline using a questionnaire administered to 182 respondents via an accidental sampling technique. The collected data were processed and analyzed using the Statistical Package for Social Science (SPSS) and Partial Least Squares Structural Equation Modeling (PLS-SEM). The results showed no significant relationship between respondents' characteristics and perceived product quality, price perception, and consumer satisfaction. Then, perceived product quality has a significant positive effect on price perception and consumer satisfaction. Price perception also has a significant positive effect on consumer satisfaction.
Keyword: consumer satisfaction, local fashion, perceived product quality, price perception

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model