Judul: Relationship between capacity of biomass formation and exploitation level of shorthead anchovy (Encrasicholina heteroloba) in Inner Ambon Bay
Abstrak: The objectives of this research were to identify and to evaluate the potency capacity of biomass formation, recruitment and growth as well as level of stock biomass utilization of shorthead anchovy (Encrasicholina heteroloba) in Inner Ambon Bay. A year sampling was conducted in three sites of Inner Ambon bay i.e. in the front (zone I), in the middle (Zone II) and in the back (zone III), in order to examine the habitat characteristics, stock distribution as well as fishing intensity and catch in both full and half-moon. The results showed that habitat characteristics which consist of hydro-oceanography factors and water quality were suitable for growth and distribution of shorthead anchovy. Capacity of biomass formation in zone I, II and III reached a maximum level in June, July and August (east monsoon) and subsequently declined in September untill November (transition II of monsoon), and relatively stable in December till/up to May (west monsoon and transition I). It was indicated that utilization level of beach seine and lift net at zones I, II and III had not exceeded capacity of stock, however capacity of eliminated stock had exceeded in a particular months or season. From 23 times sampling within one year period, it was found that stock utilization level which do not exceed eliminating carring capacity (under exploited) were 9, 8, and 9 times at zone I, II, and III consecutively. Whilst stock utilization level that exceed exploitation (over explotation) were 14, 15, and 14 at zone I, II, and III consecutively. It can be concluded that Inner Ambon Bay is a semi enclose waters that connected to Outer Ambon Bay through a ridge/sill. This area has biomass carring capacity which has experienced similar exchange i.e. increase at east monsoon, decrease at 2nd monsoon, and stable during west monsoon up to 1st transition monsoon. Stock biomass utilization level has exceeded biomass formation carring capacity that causes decrease in stock sustainability or currently this stock is under over exploitation level . From this study it was suggested that management of shorthead anchovy should be based on capacity of biomass formation and elimination with the consideration of optimal utilization level towards stock potency (stock availability and capacity of stock) up to achievable sustainability levels.
Keyword: sustainability, Encrasicholina heteroloba, ikan teri merah, ikan umpan

Judul: Analisis Bioekonomi Pengelolaan dan Pemanfaatan Sumberdaya Ikan Teri (Stolephorus sp.) di Perairan Kabupaten Asahan, Provinsi Sumatera Utara
Abstrak: Anchovy is one of important pelagic species produced in Asahan Regency. Anchovy production not only to supply local needs, but also it has been exported to neighboring countries. Based on the analysis of the declining of achovy production showed that there is problem in resource management. The objectives of this research were to study proper anchovy resource management in the Asahan sea. Analytical approaches were used bioeconomic and variance analyses. Bioeconomic analysis using Gordon-Schaefer model approach obtained the actual catchment condition (h) is 725.94 tons/year, effort (E) 947.22 trips/year and the economic rent of Rp 12,648,510,194/year. Catch of MSY level (h) is 1,200.92 tons/year, effort (E) 834.96 trips/year and the economic rent of Rp 22,951,655,440/year. Catch of MEY level (h) is 1,198.41 tons/year, effort (E) 796.75 trips/year and economic rent of Rp 23,004,560,220/year. Current exploitation rate has exceeded sustainable levels of optimal exploitation both in terms of MSY or MEY which lead to overfishing. Based on the estimation of degradation and depreciation rate, the anchovy resource in the Asahan sea has not been degradated and depreciated. This is indicated by the value of degradation and depreciation rate coefficient are 0.27774 and 0.28790. The factors that significantly correlated with fishers perception to anchovy resource are fishing gears, government programs, and the environment are the education levels, fishing experience, and the participation in fisher's organizations. Anchovy resource management can be directed toward MEY conditions to obtain the maximum benefit, but this policy has an impact on the reduction of labor. In order to absorb the larger employment and the sustainability of resource, the resource management policy is directed toward MSY level by reducing fishing gears as much 112,26 units anchovy purse seine from the current level of exploitation. This policy must be supported by clear rule/ regulations and continuous monitored by all parties.
Keyword: North Sumatera, management, bioeconomic, Asahan, anchovy

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