Judul: Analisis Penggunaan Lahan Dan Usaha Tani Komoditas Hortikultura Pada Tanah Andosol
Abstrak: Cianjur District, particularly at Pacet Subdistrict, is one region that at present has competitive advantage in terms of horticulture commodity products, especially for upland vegetables. One potential soil type for upland horticulture farming development in Indonesia is Andosol. Cultivation technique for horticulture in the location is still considering traditional pattern and not considering yet quality aspect and land use. Due to that reason, it is needed a direction for land use planning based on land suitability and economic reason that will increase land use efficiency both at farmer level and surrounding location and not cause soil degradation and environment.
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Judul: Analisis karakteristik usahatani komoditas hortikultura dan faktor-faktor yang mempengaruhinya di kawasan agropolitan pacet - Cianjur
Abstrak: Research result indicates size of the land ownership on research locations in agropolitan area (Sukatani and Sindangjaya villages) were relative narrow, with farm domination pattern for both villages were as land owner (1), as rent, sharing holder, mortage (2), as a governmental property (3). Meanwhile the farm enterprise characteristic the farmer was tends to conduct multiple cropping planting pattern (polyculture). Planting pattern was formed using four considerations, such as: (1) technique of cultivation, (2) market request, (3) the limited of capital and labour owned by farmer and (4) socio-economic condition. Crop rotation with high and quick intensity, causing type fertilizer and chemicals used immeasurable progressively. Based on farm enterprise characteristics on research location, if conducted of efficiency analysis of farm enterprise, indicate that all of R/C ratio value were above 1 that means all commodities were efficient. Meanwhile, analysis of multiple regression productivity farm enterprise productivity in agropolitan area indicate that variable having a significant effect on reality to farm enterprise advantage were land size, fertilizer, labour, and dummy variable about conservation activity (-p<0.05). There are three free significant variables in the factors of model binary logistic regression analysis that influence the farmer’s role in application of soil conservation techniques. Those are (1) land governance, (2) planting pattern, and (3) land ownership.
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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