Judul: Marketing Efficiency of Monstera Marmorata in Cihideung Village,  Parongpong District, West Bandung Regency
Abstrak: Desa Cihideung adalah salah satu wilayah di Kabupaten Bandung Barat yang menjadi sentra penghasil Monstera marmorata. Terdapat beberapa permasalahan yang dihadapi oleh petani Monstera marmorata yaitu adanya fluktuasi pada hasil produksi, perbedaan harga jual yang ada di tingkat lembaga pemasaran, dan sulitnya pendistribusian. Penelitian ini bertujuan untuk menganalisis lembaga pemasaran, saluran pemasaran, fungsi pemasaran, serta efisiensi operasional pemasaran berdasarkan indikator majin pemasaran, farmer’s share, dan rasio keuntungan atas biaya. Metode yang digunakan untuk memilih petani responden adalah simple random sampling serta responden lembaga pemasaran berdasarkan snowball sampling. Saluran pemasaran V (petani–broker-konsumen) relatif efisien dibandingkan dengan saluran pemasaran lainnya dari indikator secara keseluruhan, karena memiliki nilai marjin pemasaran Rp455.000,00 dengan persentase farmer’s share 93,46, nilai rasio keuntungan atas biaya sebesar 2,50 dan saluran pemasaran V sudah melaksanakan fungsi pemasarannya secara lengkap ditingkat pedagang dan lembaga pemasaran., Cihideung Village is one of the areas in West Bandung Regency that is the center of Monstera marmorata production. There are several problems faced by Monstera marmorata farmers, namely fluctuations in production, differences in selling prices at the marketing institution level, and difficulty in distribution. This study aims to analyze marketing institutions, marketing channels, marketing functions, and marketing operational efficiency based on indicators of marketing majors, farmer's share, and profit over cost ratio. The method used to select farmer respondents was simple random sampling and marketing institution respondents based on snowball sampling. Marketing channel V (farmer-broker-consumer) is relatively efficient compared to other marketing channels from the overall indicator, because it has a marketing margin value of Rp455,000.00 with a farmer's share percentage of 93.46, a profit over cost ratio value of 2.50 and marketing channel V has carried out its marketing function completely at the level of traders and marketing institutions.
Keyword: Cihideung, Efficiency, Marketing, Monstera marmorata

Judul: Marketing Efficiency of Galangal in Gandoang Village, Cileungsi District, Bogor Regency
Abstrak: Kecamatan Cileungsi adalah sentra penghasil lengkuas di Kabupaten Bogor dan Desa Gandoang merupakan desa di Kecamatan Cileungsi yang memiliki potensi tinggi dalam pertanian lengkuasnya. Namun, dalam pemasarannya terlihat ada permasalahan, yaitu terbatasnya pengetahuan petani tentang saluran pemasaran dan tingginya selisih harga jual di tingkat Petani dengan harga yang dibayarkan di tingkat Konsumen Akhir. Penelitian ini bertujuan untuk menganalisis sistem pemasaran lengkuas dan efisiensi operasionalnya. Metode analisis yang digunakan meliputi analisis deskriptif kualitatif dan analisis kuantitatif. Responden terdiri dari 33 orang petani lengkuas berdasarkan teknik sampling jenuh dan delapan orang lembaga pemasaran lanjutan berdasarkan teknik snowball sampling. Hasil penelitian menunjukkan bahwa terdapat empat lembaga pemasaran, yaitu Petani, Tengkulak, Pengepul, Pedagang Besar, dan Pedagang Pengecer. Saluran pemasaran yang terbentuk sebanyak dua saluran pemasaran dan sudah melaksanakan fungsi pemasaran, yaitu fungsi pertukaran, fisik, dan fasilitas. Analisis efisiensi pemasaran menggunakan metode indeks komposit menunjukkan bahwa Saluran Pemasaran II merupakan saluran yang paling efisien dengan margin pemasaran sebesar Rp13.333, farmer’s share sebesar 33,33%, dan rasio keuntungan terhadap biaya sebesar 2,02., Cileungsi District is a galangal-producing center in Bogor Regency and Gandoang Village is a village in Cileungsi District which has high potential for galangal farming. However, in its marketing there are problems, namely the limited knowledge of farmers about marketing channels and the high difference between the selling price at the Farmer level and the price paid at the Final Consumer level. This research aims to analyze the galangal marketing system and its operational efficiency. The analytical methods used include qualitative descriptive analysis and quantitative analysis. Respondents consisted of 33 galangal farmers based on census sampling and eight marketing institutions based on snowball sampling. The results showed that there are four marketing institutions: farmers, middlemen, collectors, wholesalers, and retailers. Two marketing channels have been formed and have implemented marketing functions, namely exchange, physical, and facility functions. Marketing efficiency analysis using the composite index method shows that Marketing Channel II is the most efficient channel with a marketing margin of IDR13.333, a farmer's share of 33,33%, and a profit-to-cost ratio of 2,02.
Keyword: cost, efficiency, marketing, Biaya, efisiensi, Pemasaran, composite index method, galangal, lengkuas, metode indeks komposit

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