Judul: Technical efficiency analysis and farmer risk behavior as well as its effects on the superior variety application in potato farming in Enrekang Regency, South Sulawesi Province
Abstrak: The main problem in potato commodity development in Enrekang Regency is the productivity which tends to decrease. This study aimed to: (1) estimate the level of technical efficiency and the factors that influenced it on potato farming, (2) learn about the behavior of farmers in the face of productivity risk in farming potato, (3) estimate the factors that influenced farmers' opportunities in applying superior varieties in potato farming. This study used 77 samples of farmer respondents who grew potato of granola variety and 30 farmer respondents who grew potato of kalosi variety in Enrekang Regency. A function model of frontier productivity, productivity risk function and technical inefficiency function which was developed by Kumbhakar was adopted to analyze the technical efficiency and farmer behavioral risks and logit model to analyze the factors that affected farmers' opportunities to apply technology and was estimated by Maximum Likelihood Estimation. The research result showed that: (1) the behavior of farmers who grew potato of granola variety and those who grew potato of Kalosi variety was risk averse, (2) the average level of technical efficiency accomplishment of potato farming using granola variety and Kalosi variety was classified as high, (3) socio-economic factors that had an effect on lowering technical inefficiency in potato farming with granola variety were potato farming experience, household size and the land distance from the farmer's house, while in potato farming using kalosi variety were potato farming experience and the land distance from the farmer's house, and (4) the productive age and availability of labor in the family affected the farmer’s chances of applying superior varieties in potato farming.
Keyword: technical efficiency, superior varieties, risk behavior, technological application, potato

Judul: Efficiency and sustainable value of highland vegetables in West Java
Abstrak: The goals of this research are to estimate technical, allocation, and economic efficiencies of highland potatoes and cabbage, to identify the factors affecting those efficiencies, and to estimate the sustainable values of those crops. The research is conducted in Bandung and Garut district by doing a survey to 200 selected farmers. The data are then analyzed using Frontier 4.1. program. The result of this study indicated that (1) land area is the most important resource, land slope significantly affect productivities of both potatoes and cabbage while chemical fertilizers (N, P, and K), pesticide, and labor do not significantly affect productivities of both potatoes and cabbage, (2) efficiencies of both crops are significantly affected by farmers age, experience, group membership, frequencies of extention, access to credit, land ownership status and planting system, (3) sustainable value of the farms are significantly affected by the land slope and types of planting system. The farmers efficiencies could be improved by providing training programs to improve their managerial capability and to control land degradation (erosion)
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Judul: Formulasi Hamiltonian untuk Menggambarkan Gerak Gelombang Soliter Dimensi Tiga di Permukaan Laut
Abstrak: Gelombang permukaan adalah gelombang yang terjadi perbedaan rapat massa antara air dan udara. Salah satu gelombang permukaan yang ditinjau adalah gelombang soliter. Formulasi gelombang soliter dilakukan dengan menggunakan formulasi Hamiltonian.
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