Judul: Analisis Metode Indeks Kepekaan Lingkungan Ekosistem Mangrove terhadap Tumpahan Minyak, Studi Kasus di Wilayah Pesisir Kabupaten Subang
Abstrak: Mangrove ecosystem is one of the coastal ecosystems that very vulnerable to oil spills. Oil spill on mangrove ecosystem can cause direct mortality. Oil polution in the long term on mangrove ecosystem can disturb another organism that live in mangrove, also influencing socio-economic life of people who depend their life to mangrove ecosystem. With the result that, efforts to prevent or minimize the risk of oil spills in coastal areas is needed. Enviromental sensitivity index (ESI) is an index that can determine the sensitivity level of environmental to oil spills. This research aims to develop environmental sensitivity index of mangrove ecosystem in the coastal area of Subang, West Java Province to oil spill. Types of data were used in this study consists of primary data and secondary data. Primary data was obtained by survey in the field, while secondary data was obtained by literature study. Primary data was collected including mangrove ecosystem data, type of substrates, and socio-economics data that related to mangrove ecosystem. While secondary data was including coastal physical characteristics and hydrooceanography. These data were used to form ESI parameters. Furthermore the ESI was applied in the studied area and then the sensitivity area was shown on ESI map. The ESI was comprised of three types of index consist of vulnerability index (VI), ecology index (EI), and socio-economic index (SI). The paramaters of VI consist of slope, tides, tidal range, height of wave, type of substrate, and mangrove distance from the coast. The parameters of EI consist of mangrove zonation, density of mangrove, diversity of mangroves, stage of mangrove, protected wildlife, and status of mangrove protection. The parameters of SI consists of two components including social and economic components. The social component was based on mangrove resource utilization by human, such as fisheries potential, wood potential, and tourism potential, while the economic component was counting from biomass of mangrove. The formula of ESI was used is ( ) ( ) it divided into 5 sensitivity levels (not sensitive, less sensitive, moderate, sensitive and very sensitive). Generally coastal areas of Subang were slightly slope, mixed semidiurnal of tidal type, average wave height is 0.4 meters, muddy substrate and mangrove found in the shoreline. In observation areas founded three genus of mangrove (Avicennia sp, Sonneratia sp, and Rhizophora sp.) with different densities. The mangrove ecosystem at Subang is protected area. Protected wildlife did not found on mangrove ecosystem. Mangrove used for fisheries activities (as an area of ponds, catching eels and crabs) and the use of wood (as fuelwood, building materials, materials for fishing gear). The ESI aplication on mangrove ecosystem in observation areas showed that some mangrove have sensitive and moderate ESI level. The most of areas moderate to oil spill except to Tegal Tike, Anggaranu, and Tanjung. These area are sensitive to oil spill
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Judul: Tingkat Kepekaan Lingkungan Ekosistem Mangrove di Kecamatan Ujung Pangkah Kabupaten Gresik Provinsi Jawa Timur
Abstrak: Mangrove ecosystem in Ujung Pangkah District Gresik Regency has an important role in human life, flora, and fauna in the delta of Bengawan Solo River. The existence of this mangrove ecosystem is also threatened by pollution from oil spills, either from industrial activities on land, as well as in waters such as tanker crashes, port activities, ship operations, oil loads, leaks and explosions during offshore oil exploration, and Some other activities in the upstream area. The purpose of this research is to determine the level of environmental sensitivity of mangrove ecosystem to oil spill in Ujung Pangkah Sub-district by using geographic information and remote sensing application system. There are about 8.16% of Ujung Pangkah Subdistricts that fall into the category of very sensitive. This type is located in the mudflat area and the most dominant is in the pond. Overall, sensitivity categories with sensitivity rates were the dominant category with approximately 82.67%. This category lies in an ocean of 4,765.68 hectares and on land covering 5,919.61 hectares. Furthermore, based on SWOT analysis, there are 10 strategies to overcome the impact of oil spill in ecosystem mengrove Ujung Pangkah District with sensitivity category at "very sensitive" level, namely: 1) zoning of zone of environmental sensitivity, 2) socialization of traditional fishing zone, 3) Participatory mapping, 4) Maintaining greenbelt area from occupation of land, 5) Planting in greenbelt area, 6) Formation of local regulations on greenbelt, 7) Disaster adaptation and mitigation, 8) Formation of disaster taskforce, 9) Simulation of oil spill response, 10) Monitoring Forum Environment openly and periodically.
Keyword: Bengawan Solo River, geographic information system, oil spill, remote sensing, SWOT

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf