Judul: Kajian bioekologi udang putih (Penaeus merguiensis de Man)
Abstrak: White shrimp abundance is greatly influenced by food availability, existence of predators and competitors, as well as by characteristics of mangrove habitat. Changes in habitat quality in mangrove ecosystem directly affects the growth of this biota. The objective of the research were to determine suitable habitat characteristics of white shrimp based on maturity stage, and to determine spawning peak season and recruitment of white shrimp in mangrove ecosystem of Percut Sei Tuan North Sumatera. White shrimp habitat characteristics was evaluated based on biophysical and chemical parameters of environment at each station using principal component analysis. Spatio-temporal distribution was evaluated based on gonads maturity index using correspondence analysis. Temporal distribution of female white shrimp was evaluated based on the maturity of gonads in each observation month. Correlation analysis of white shrimp spatial distribution with size, sex, gonads maturity, and mangrove species at each station/zone was also performed. Principal component analysis results described that correlation between parameters centered on two main axes, each explaining 76.27% and 17.62% of total range. The analysis classified three groups of individuals/station. Group I consisted stations 1, 2, and 3 characterized by dissolved oxygen, nitrate, phosphate, current speed, and clay substrate. Group II consisted stations 4 and 5 characterized by mangrove density, litter production, plankton abundance and macrozoobenthos, and high litter decomposition rates. Group III consisted of six stations characterized by water temperature, brightness, depth, salinity, pH, and high sand substrate. Analysis of white shrimp spatial distribution based on gonads maturity level using correspondence analysis showed information which centered on two main axes, each explaining 65.17% and 28.60% of total range. Analysis results also showed female adult white shrimps with mature gonads were found in waters which have temperature 29.00°C - 30.5°C, salinity 31‰ - 31.20‰, and pH 7.05 - 7.40. Spawning peak season of white shrimp in Mangrove Ecosystem of Percut Sei Tuan in June and January, and recruitment between September and October, as well as February and March.
Keyword: White Shrimp, Penaeus merguiensis, spatio-temporal distribution, mangrove ecosystem

Judul: Kajian penangkanapan udang putih kecil (Metapenaeus lysianassa, de Man 1888) sebagai aplikasi pengelolaan di muara Sungai Kakap Kabupaten Pontianak Kalimantan Barat
Abstrak: Small white shrimp (Metapenaeus lysisanassa) fishery using setnets in Sungai Kakap estuary increased from the year 1994 to 2005 and this sector gave a lot of benefit for fishermen. The advantages of this shrimp fishery are providing work and income for local people, providing of nutritious food for human life and local government income from tax or retribution. However, the increasing fishermen effort to catch small white shrimp in this estuary is estimated to be followed by decreasing of their productivities and declining of CPUE trend. The objectives of the study are to obtain distribution pattern of small white shrimp caught by setnet and to obtain CPUE (Catch per Unit Effort) trend of small white shrimp fishery. Eleven stations were established in this site to learn distribution pattern of small white shrimp caught by setnet and time series data of catch and effort was used to calculate the trend of CPUE. The study got information that distribution pattern of small white shrimp was caught in higher numbers in salinity interval 5 – 7‰. Bigger sizes of small white shrimp were found in salinity 10 - 20‰. CPUE of small white shrimp caught by setnet tends to decrease during twelve years.The study result is expected to give information for management plan to manage of small white shrimp fishery.
Keyword: 

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular