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: Performance and Value Added Improvement Through Re-Engineering Coffee Supply Chain of AMANAT Farmer Group Nanggung Village
Abstrak: Kelompok Tani AMANAT mendapatkan redistribusi lahan ex-HGU melakukan budidaya kopi dan pasca panennya secara otodidak. Hal ini menyebabkan mutu green bean yang dihasilkan masih rendah. Penelitian ini bertujuan untuk mengetahui kondisi rantai pasok, mengukur kinerja rantai pasok, menghitung nilai tambah rantai pasok, merumuskan strategi peningkatan kinerja dan nilai tambah, dan merekayasa ulangrantai pasok yangada pada Kelompok Tani AMANAT. Pada kondisi existing rantai pasok kopi yang dilalui oleh anggota kelompok Tani AMANAT terdiri dari petani kopi, pengepul, pengolah, retailer dan konsumen akhir. Petani kopi sebagai pemasok memiliki nilai kinerja rantai pasok yang diukur menggunakan model AHP-SCOR DS sebesar 55,87% dan termasuk kategori average. sedangkan nilai tambah yang dihitung menggunakan model Hayami termodifikasi didapatkan petani saat ini memiliki rasio sebesar 2,78% dan temasuk pada kategori peningkatan nilai tambah yang rendah. Untuk mengatasi tersebut didapat alternatif strategi yang dirumuskan menggunakan model ANP berupa pemberdayaan kelompok tani untuk pengelolaan kopi bersama sebagai alternatif strategi terpilih untuk diterapkan oleh petani. Setelah itu dilakukan rekayasa ulang rantai pasok yang menghasilkan coffee roastery dan kedai kopi menjadi aktor baru pada rantai pasok yang sudah ada sebelumnya sebagai model perbaikan yang diharapkan dapat meningkatkan kinerja dan nilai tambah yang didapat oleh Kelompok Tani AMANAT., The AMANAT Farmer Group who received the ex-HGUland redistribution carried out self-taught coffee cultivation and post-harvesting. This causes the quality of the green beans produced is low. This research aims to determine the supply chain conditions, measure supply chain performance, calculate supply chain added value, formulate strategies to improve the performance and added value, and re-engineer existing supply chains in the AMANAT Farmer Group. In the existing condition of the coffee supply chain that is traversed by the members of AMANAT Farmer Group consist of coffee farmers, collectors, processors, retailers and end consumers. The coffee farmers as suppliers have a value of supply chain performance as measured using the AHP-SCOR DS model of 55.87% and are included in the average category, while the added value calculated using the modified Hayami model shows that farmers currently have a ratio of 2.78% and are included in the category of low added value. To overcome this, an alternative strategy is obtained which is formulated using the ANP model in the form of empowering farmer groups for joint coffee management as an alternative strategy chosen to be implemented byfarmers. After that, a supply chain re-engineering was carried out which resulted in the coffee roastery and coffee shop becoming new actors in the existing supply chain as an improvement model that was expected to increase the performance and added value obtained by the AMANAT Farmer Group.
Keyword: added value, coffee, performance, re-engineering, supply chain

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
Keyword: