Judul: Model Inventori Deterministik dengan Diskon, Backorder, dan Penundaan Pembayaran
Abstrak: Inventory has a very important function for companies. The companies store variety of goods such as raw materials, goods for industrial processes, and other goods. The storages are required to keep the goods fulfill and buyers demand in a quick time. This paper discussed a deterministic inventory model. If the amount goods in the inventory is less than the buyers’ demand, then there is shortage of inventory. This would delay the demand for goods from the buyer to be fulfilled and the managers of the company would offer discounts to consumers for such a delay. By the delay time of payment, the company will know when the inventory ending time and reorder time so the total inventory cost would be minimized. The optimum ordering policy and the offered discount for the optimum shortage of inventory can be used to determine the minimum total inventory cost.
Keyword: Price discount., Inventory, Deterministic model, Delay in payment

Judul: Optimization of Inventory Model with Constant Level of Deterioration and Credit Payment
Abstrak: Persediaan adalah stok barang yang disimpan oleh distributor atau perusahaan yang dijual kepada pelanggan di waktu yang akan datang. Untuk memenuhi permintaan pelanggan, diperlukan pengendalian persediaan dengan menentukan kapan barang akan dipesan dan kuantitas barang yang dipesan agar biaya total yang dikeluarkan minimum. Dalam sistem ini terjadi beberapa jenis barang yang dapat mengalami kerusakan sehingga tidak dapat disimpan dalam jangka waktu yang lama. Selain itu, distributor memiliki situasi tidak dapat membayar biaya pembelian secara tunai kepada pemasok atau manufacturer sehingga dilakukan pembayaran dengan sistem kredit. Karya ilmiah ini membahas model Economic Order Quantity dengan tingkat kerusakan konstan dan pembayaran secara kredit. Untuk itu diformulasikan masalah persediaan untuk menentukan banyak pesanan dan periode pengisian ulang sehingga dapat meminimumkan biaya total persediaan. Selain itu, ditinjau pula pengaruh tingkat kerusakan, tingkat suku bunga, dan batas waktu kredit terhadap periode pengisian ulang, kuantitas barang yang dipesan, dan biaya total persediaan., Inventory is stock items stored by distributors or companies that are sold to customers in the future. In order to meet customer demand, inventory control is needed by determining the order time and the order quantity so that the total costs incurred are minimum. In this system, several types of items can deteriorate so that they cannot be stored for a long period of time. Furthermore, the distributor has a situation where he cannot pay the purchase cost in cash to the supplier or manufacturer so that payment is made using the credit system. In this work, we discuss the Economic Order Quantity model with constant level of deterioration and credit payments. For this purpose, an inventory problem is formulated to determine the number of orders and the replenishment period so as to minimize the total cost of inventory. In addition, it is also examined the effect of the level of deterioration, interest rates, and credit times limits on the replenishment period, the quantity of items ordered, and the total cost of inventory.
Keyword: credit, Economic Order Quantity, inventory, optimization

Judul: Light Microscope Study of ConnectiveTissue in The Spleen of Common Rousette Bat (Rousettus amplexicaudatus)
Abstrak: The spleen is the largest lymphoid organ. As a secondary lymphoid organ, in addition to its immune function, the spleen also has functions as blood filtration, storage, and hematopoiesis. The spleen has different morphologies between species that support different physiological functions, one of which is the difference in the structure of the capsule and trabeculae. Capsule and trabeculae of the spleen generally consist of connective tissue and smooth muscle. The thickness of smooth muscle composed together with connective tissue in the capsule and trabecula determines the function of the spleen that is divided spleen into three storage, defense, and intermediate. Bats are the reservoir of various zoonotic diseases. Bats are thought to have unique immune systems compared to other mammals but the characteristics of its immune organs such as the spleen have never been studied before. This study was conducted to examine the characteristics of capsulae and trabecula of the Common Rousette (Rousettus amplexicaudatus).
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