Judul: Penyelesaian masalah manajerial dengan metode iterasi kebijakan pada discounted markov decision prosesses
Abstrak: The aim of this paper is to solve a amanagement problem in advertising and production that have been formulated into a stochastic model of the decision-making system. The Decision-making technique used in this paper is the Markov decision process with policy iteration method. To determime the optimal policy, it employed the discounted-return policy improvement algorithm that uses a discount factor equal to 0.9 for each case. In the case of advertising, the manufacturers will use RCTI as a promotion media when their product sales are low and Indosiar when they have a good sales. When they have satisfied sales, they use SCTV as media promotion. In the case of production management, farmers must keep the fishes in the pond at least 2 tons when they harvest their fishes.
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Judul: Kontrol Optimum pada Masalah Periklanan
Abstrak: Advertising is a form of communication and promotion of goods or services. It aims to convey the information in form of a message through the media and persuade that generate responses from audiences. A company must pay some additional cost to make advertising. Thus, it generates new problems, because in general a company will attempt to maximize the profit. It is necessary to find a right advertising policy from the company to allocate their advertising budget with some constraints. This paper discusses the sales-advertising response model that emphasizes the relationship between advertising costs and sales levels. The advertising models used in this paper are V-W model and Contagion model. Advertising problem is formulated in a form of optimal control problem which involves the S-shaped response function as a form of application for the solutions of profit maximization problem. The optimum control problem is solved using Pontryagin’s maximum principle. Then, fixed points of the models are analyzed. From V-W and Contagion models it can be concluded that if the cost of advertising is constant then it will be obtained a constant level of sales, so that obtained constant profits rate is over time. Involvement of S-shaped response function produced three fixed points, i.e. stable node, saddle and unstable spiral. The simulation results show that at the beginning, the company has not advertised, there is no incentive for the company to produce. Then, after the company begins to advertise, the level of benefits is still very small even resulted in a negative value at Contagion model. The reason is because it costs too much while the sales rate can not cover the costs of making advertising. At third fixed point, the rate of return insulated and enlarged from time to time as long as a company is still productive.
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Judul: Karakteristik Anatomi Skelet Tubuh Buaya Senyulong (Tomistoma schlegelii)
Abstrak: Buaya senyulong (Tomistoma schlegelii) merupakan buaya besar yang rentan punah dan hanya dapat ditemukan di rawa dataran rendah, danau dan sungai di Sumatera bagian timur, Kalimantan dan Jawa Barat (Indonesia), Serawak, Semenanjung Malaysia (Malaysia) serta Brunei Darussalam. Tujuan dari penelitian ini adalah mempelajari karakteristik anatomi skelet tubuh buaya senyulong yang dikaitkan dengan fungsi dan perilakunya. Penelitian ini menggunakan satu set preparat skelet tubuh buaya senyulong. Parameter penelitian meliputi pengamatan bentuk bagian skelet yang khas, mengukur panjang dan lebar tulang, serta dibandingkan dengan skelet tubuh jenis buaya lain, biawak air (Varanus salvator) maupun literatur yang terkait dengan sistem skelet tubuh hewan. Karakteristik anatomi skelet tubuh buaya senyulong relatif mirip pada jenis buaya lain. Beberapa karakteristik yang ditemukan yaitu, proatlas pada os atlas, os axis hanya memiliki zygapophysis caudalis, bagian lateral dari ossa vertebrae cervicales yang dilengkapi dengan cervical ribs, memiliki jumlah costae sternalis yang banyak, rangkaian ossa gastralia pada abdomen, ossa vertebrae lumbales memiliki zygapophysis cranialis dengan sudut >90o dari sumbu tubuh. Selain itu, os vertebrae caudalis I memiliki caput cranial dan caudal, ossa vertebrae caudales memiliki processus transversus yang semakin memendek ke arah caudal. Di medioventral tulang ini ditemukan ossa chevron dengan hemal arch sampai menjelang akhir ossa vertebrae caudalis. Skelet tubuh buaya senyulong memiliki hubungan yang kokoh dan kompak untuk menunjang fleksibilitas tubuh untuk berjalan, berenang dan berburu mangsa
Keyword: anatomi, buaya senyulong, skelet tubuh