Judul: Desain proses pengolahan pada agroindustri kopi robusta menggunakan modifikasi teknologi olah basah berbasis produksi bersih
Abstrak: Coffee in Indonesia included 5 main crops commodities, and 10 main export commodities. Since 2008, Indonesia is the third exporter countries after Brazil, and Vietnam. Coffee has been shown to have definitely beneficial for Indonesian farmer as source of income, and contributes for regional development, so its sustainability should be maintained. One of constraints faced by farmers is low quality of coffee beans due to post-harvest handling. Most coffee producer in Indonesia is smallholder Robusta coffee which used to dry process for coffee berry. Application of wet process is more sophisticated than the dry process, but leads to better quality coffee bean, though need high input of water, and produce wastewater that can pollute the environment. It should be designed coffee processing based on clean production to minimize, and prevent the wastewater generated from processing. Development of processing technologies based on cleaner production is a part of sustainability development strategies on smallholder coffee agroindustry. Therefore, the main objective of this research is to design sustainability of smallholder coffee processing using wet technology that has quality oriented to improve farmer productivity, and incomes without dismissing social, and environmental interests. In particular, the general objective is achieved through several phases with their aims as follows; (1) to formulate coffee agroindustry sustainability framework based on economic, environmental, social, and institutional indicators, (2) to determine the sustainability status of smallholder coffee agroindustry, (3) to modify wet technology on Robusta coffee processing by water minimizing, (4) to design of waste treatment system on smallholder coffee agroindustry, (5) to formulate the structure of smallholder coffee agroindustry development which based on cleaner production. Research is conducted through several stages in the research field of coffee plantation area (Sidomulyo village, Jember Regency), laboratories (Jember University, and AWMC, The University of Queensland), and pilot plant unit (Indonesian Coffee and Cocoa Research Institute). Sustainability analysis showed the value of sustainability is 58,94% (sustainable enough) with 10 main leverage factors. Modified wet technology through water minimization can reach optimum levels at 2,987 – 3,345 m3/tonne of coffee berry. Within this volume, the quality of green coffee could be maintained, and wastewater minimized until 67% compared to conventional wet processing. Waste treatment designed of coffee processing have been done through reduce, reuse, and recycle (3R) to obtain the economic value of by-products. Economic analysis showed smallholder coffee agroindustry which applied modified wet technology based on cleaner production has higher feasibility, and flexibility compared with the dry processing mainly deal with fluctuation of world coffee prices. Development of smallholder Robusta coffee can be performed based on the structures of needs, constraints, required changes, goals, and indicators obtained through the ISM simulation.
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Judul: Design of Coffee Processing Improvement as an Effort to Increase the Quality of Green Bean Robusta Farmer Group AMANAT Nanggung Village
Abstrak: Peningkatan kualitas produk merupakan salah satu upaya dalam keberlanjutan agroindustri kopi rakyat. Kelompok Tani AMANAT Desa Nanggung terpilih sebagai usaha kopi tani yang potensial untuk dikembangkan. Proses pengolahan kopi oleh petani Kelompok Tani AMANAT Desa Nanggung masih menghasilkan green bean yang belum memenuhi standar SNI dan termasuk kategori mutu asalan sehingga perlu dilakukan perbaikan. Metode yang digunakan terdiri dari eksplorasi, pendefinisian masalah, ideasi, pengembangan prototipe dan validasi. Hasil dari penelitian berupa prototipe desain proses pengolahan pascapanen metode natural yang sudah diperbaiki tahapannya dan proses pengolahan metode honey. Perbaikan yang dilakukan yaitu dengan penambahan proses sortasi basah, perpanjangan lama waktu pengeringan, dan pemaksimalan proses sortasi kering. Berdasarkan hasil penelitian, green bean hasil perbaikan metode natural dan metode honey dapat memenuhi syarat mutu umum SNI Biji Kopi dengan kategori mutu grade 1., Improving product quality is one of the efforts in the sustainability of the people's coffee agro-industry. The AMANAT Farmer Group in Nanggung Village was selected as a potential farming coffee business to be developed. The coffee processing by AMANAT Farmer Group farmers in Nanggung Village still produces green bean that does not meet SNI standards and belongs to the category of random quality, so improvements need to be made. The method used consists of exploration, problem definition, ideation, prototype development and validation. The results of the research are in the form of a design prototype for post-harvest processing using the natural method which has improved its stages and the processing using the honey method. Improvements made are by adding a wet sorting process, extending the drying time, and maximizing the dry sorting process. Based on the results of the research, green beans resulting from the improvement of the natural method and the honey method can meet the general quality requirements of SNI Coffee Beans with grade 1 quality category.
Keyword: Green bean, post harvest, processing, quality, SNI

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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