Judul: Analisis Persediaan Bahan Baku Untuk Produksi Jus Buah Pada PT Amanah Prima Indonesia
Abstrak: There are many fresh fruits processing companies, some of which has been registered in Indonesia. In their operation, these companies need raw materials. The purpose of this study was to analyze the stock of raw materials for fruit juices production at the beverage drinks industry (case study at PT Amanah Prima Indonesia). The analysis has been conducted on the condition of stock, to determine the optimal amount and frequency of purchase of raw materials both in the form of fresh fruits and puree, and re-ordering point of the fresh fruits. The Economic Order Quantity (EOQ) method was used to determine the optimal amount of raw materials purchased. The result of the inventory analysis with the EOQ method indicated that: (1) the optimal amounts of raw materials purchased of each fresh fruits in 2009 and 2010 are 231 kg/order and 311 kg/order with the frequency of purchases is 17 and 22 times for apple, 964 kg/order and 1.227 kg/order with the frequency of purchases is 69 and 88 times for guava, 295 kg/order and 408 kg/order with the frequency of purchases is 21 and 29 times for pineapple, 633 kg/order and 565 kg/order with the frequency of purchases is 46 and 41 times for soursop, and 186 kg/order and 208 kg/order with the frequency of purchases is 13 and 15 times for strawberry, (2) the optimal production amounts of puree to meet the demand of fruit juices in 2009 and 2010 are 32 kg/production periods and 44 kg/ production periods with the frequency of productions is 109 and 147 times for apple, 128 kg/production periods and 163 kg/ production periods with the frequency of productions is 429 and 547 times for guava, 38 kg/production periods and 53 kg/production periods with the frequency of productions is 128 and 177 times for pineapple, 86 kg/production periods and 77 kg/production periods with the frequency of productions is 290 and 259 timess for soursop, and 26 kg/production periods and 30 kg/production periods with the frequency of productions is 89 and 100 times for strawberry. To avoid the shortage of raw materials, the company has to re-order when the stock of raw materials of each fresh fruits at the warehouse in 2009 and 2010 are 51 and 99 kg for apple, 991 and 1.204 kg for guava, 115 and 182 kg for pineapple, 562 and 308 kg for soursop, and 55 and 41 kg for strawberry. The result of EOQ analysis also indicated that the company could save their expenditure for raw materials of guava and soursop. The company could use this EOQ policy provided that the availability of the raw materials in the form of fresh fruit could be guaranteed and the amount of demand relatively stable.
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Judul: Analisis Pengendalian Persediaan Buah Segar dengan Pertimbangan Laju Kerusakan pada Industri Jus Buah (Studi Kasus CV MMB)
Abstrak: Komoditas pertanian seperti buah tergolong perishable inventory yang memiliki umur simpan terbatas dan penurunan mutu secara eksponensial seiring waktu. Di samping itu, kesegaran merupakan parameter utama mutu buah yang akan diolah sehingga perlu dilakukan pengendalian persediaan buah dengan pertimbangan laju kerusakan. Tujuan penelitian ini yaitu untuk menentukan kebijakan pengendalian persediaan agar biaya persediaan minimum. Model perishable inventory merupakan model persediaan dimana persediaan berkurang karena permintaan dan kerusakan bahan. Berdasarkan analisis ABC, jeruk terpilih sebagai objek penelitian. Tingkat kerusakan berdistribusi eksponensial dengan parameter kerusakan (λ) sebesar 1.5504 dan parameter laju kerusakan/ hari (α) sebesar 0.645%/ hari. Pemesanan jeruk dilakukan oleh perusahaan sebanyak 2 kali dalam jumlah 658.28 kg/ pemesanan, sedangkan pemesanan jeruk model perishable inventory pada waktu siklus 2 hari sebanyak 20 kali dengan jumlah 64.45 kg/ pemesanan. Biaya persediaan minimum diperoleh dari hasil model perishable inventory.
Keyword: buah, eksponensial, mudah rusak, optimasi, persediaan

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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