Judul: Rancang bangun model berbasis agen untuk pengembangan agroindustri udang di kawasan minapolitan
Abstrak: Agroindustry is a very important component in the agricultural supply chain. Shrimp agroindustry is an industry that can add value to the shrimp commodity. Since it has a strategic position in the agricultural supply chain, this industry need to be maintained its sustainability. The sustainability of shrimp agroindustry depends on the conditions of shrimp supply. If raw material supply increases, it will positively impact on the sustainability of shrimp commodity. On the contrary, a decrease in shrimp production resulted in disruption of the supply of raw materials and, in turn, damaging the sustainability of shrimp agroindustry. One attempt to increase shrimp production is the development of Minapolitan program. Minapolitan can be considered as an effort to implement fair and sustainable economic development through rural development focusing on fisheries as a cluster developing point. However, the development of Minapolitan zone has not had significant positive impact. Current fisheries production is stagnant and declining due to various things such as disease, unfavorable climatic conditions, cultivation management, quality seeds, and others. There are many elements that should be accommodated in the development of Minapolitan leading to the complexity and the social dynamic of this program. Agent-based model approach in the development of Minapolitan for sustainable shrimp agroindustry will provide simulation model for the sustainability of shrimp agroindustry. This simulation model was constructed from interaction between each autonomous agent within a cluster. The agent-based approach was started from identifying types of agents within Minapolitan cluster of shrimp agroindustry, the agent’s behaviour, the interaction between agents, the agreements among agents, and the interaction between agents and the environment. The next step was constructing a cluster model based on the principles of sustainability. The simulation model resulted from this study is not only able to determine the sustainability, but also is able to simulate policy scenarios to predict changes in the interaction among agents and the impact of the changes to the sustainability of shrimp agroindustry. The analytical ability and the policy scenario simulation will be useful for decision makers in formulating strategy of shrimp agroindustry sustainability in Minapolitan cluster’s. To increase the level of sustainability of shrimp agroindustry, a simulation of scenarios related to the activity of agents in Minapolitan has been done. The scenarios have been changed focusing on the efforts related to the activities of farmers in increasing the production of shrimp. The increase of shrimp production is very important because the activity in the Minapolitan cluster is closely related to the volume of shrimp production. In summary, the development of shrimp agroindustry cluster model has been designed to predict the sustainability of Minapolitan area by conducting some simulations that may occur in the real system. The results of simulation model shows that the current Minapolitan program can be considered sustainable. Farmer’s behavioural changes in choosing shrimp seeds, in optimizing fishpond area, and in improving aquaculture managerial skill could increase the production of shrimp and the profit. Improving the management of post-harvested shrimp conducted by middleman could also increase the percentage of the product purchased by agroindustrial companies in the Minapolitan zone.
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Judul: Rancang bangun model berbasis agen untuk pengembangan agroindustri udang di kawasan minapolitan
Abstrak: Agroindustri merupakan komponen penting dalam jaringan rantai pasok komoditas perikanan maupun pertanian. Agroindustri udang sebagai salah satu jenis agroindustri merupakan salah satu industri yang dapat meningkatkan nilai tambah bagi komoditas udang. Posisi strategis dari agroindustri udang dalam jaringan rantai pasok, menjadikan keberadaan industri ini perlu dipertahankan keberlanjutannya. Keberlanjutan agroindustri udang salah satunya sangat bergantung pada kondisi pasokan komoditas udang. Pasokan bahan baku agroindustri udang bergantung pada produksi komoditas tersebut. Produksi udang yang meningkat akan meningkatkan pasokan bahan baku. Semakin tinggi pasokan bahan baku, maka keberlanjutan agroindustri udang semakin meningkat. Begitu juga sebaliknya, penurunan produksi udang mengakibatkan terganggunya pasokan bahan baku dan berdampak terancamnya keberlanjutan agroindustri udang. Komoditas udang dalam tahun-tahun terakhir mengalami kecenderungan penurunan produksi. Penurunan produksi udang terlihat pada tahun 2009, sebesar 350 ribu ton lebih kecil dari tahun sebelumnya yang mencapai 410 ribu ton. Produksi tahun 2009 tersebut menurun dari target yang telah ditetapkan sebesar 540 ribu ton. Salah satu usaha meningkatkan produksi udang yang diusahakan pemerintah adalah dengan program Minapolitan. Minapolitan merupakan konsepsi pembangunan ekonomi kelautan dan perikanan berbasis kawasan berdasarkan prinsip-prinsip terintegrasi, efisiensi, berkualitas dan percepatan. Konsep Minapolitan bertujuan untuk meningkatkan produksi, produktivitas, kontinuitas pasokan dan kualitas produk perikanan dan kelautan serta menjaga kelestarian lingkungan. Peningkatan produksi ini diharapkan dapat meningkatkan pendapatan masyarakat perikanan dan keberlanjutan Minapolitan. Komoditas udang menjadi salah satu komoditas unggulan yang diusahakan dalam pengembangan kawasan Minapolitan. Kendala dalam mencapai keberlanjutan agroindustri udang seperti kurangnya pasokan bahan baku, rendahnya tingkat pendapatan petambak, perbedaan kepentingan antar pelaku dalam klaster serta adanya isu-isu pencemaran lingkungan menyebabkan kompleksitas dalam pengembangan agroindustri udang di kawasan Minapolitan semakin tinggi. Kompleksitas permasalahan tersebut diharapkan dapat dipecahkan melalui pendekatan berbasis agen. Pendekatan model berbasis agen, diharapkan mampu menyelesaikan kompleksitas permasalahan tersebut dengan mengidentifikasi semua perilaku agen yang ada dalam klaster Minapolitan dan interaksinya, sehingga dapat memprediksi kinerja pengembangan agroindustri udang di kawasan Minapolitan berdasar paradigma pembangunan berkelanjutan.
Keyword: Agroindustri, Sustainable Minapolitan, Agent-Based Simulation Model, Shrimp Production

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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