Judul: Penentuan Periode Optimal Amortization Gains and Losses dengan Meminimumkan Ragam Kontribusi Jangka Panjang
Abstrak: Amortization gain and loss method is a method to determine supplementary contributions for defining benefit pension funds. In any pension fund, profits or losses are always occur. Gains or losses are caused by the difference in the interest rate return on investment assumption and the actual rate of return. Losses must be covered in order to meet retirement benefit. Supplementary contributions to cover losses with the same payment mechanism at some periods, which are the optimal period; minimizing the range of long-term contribution as expected in the longterm the contribution be applied to program participants will be stable for each years. The optimal period of amortization gain and loss method is twenty-two years and the variance of long-term contribution is 0.000157
Keyword: optimal period, minimum variance of contribution, interest rates, mortization gain and loss method

Judul: Penentuan Periode Optimal Spreading Gains and Losses dengan Meminimumkan Ragam Kontribusi Jangka Panjang
Abstrak: The purpose of this paper is to determine optimal periods of spreading gains and losses on defined benefit pension funding plan. The principle of spreading gains and losses method is by spreading gains and losses to some periods. The optimal period is determined by minimizing the variance of long-term contribution. This paper assumes that losses are caused by the difference of actuarial rate and actual rate of investment return. The illustration of this paper uses three cases which standard deviations of actual rate of investment return are 0.0025, 0.1, and 0.25. The optimal period for three cases are acquired 12 years, 11 years, and 8 years, and standard deviation of long-term contribution for three cases are acquired 0.011, 0.469, and 1.355. It is concluded that the variance of actual rate of investment return and the variance of long-term contribution are comparable but the variance of actual rate of investment return and the optimal period of spreading losses are inversely proportional
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Judul: Phylogeography and Species Limits in the Papuan White Snake (Micropechis ikaheka) (Reptilia: Serpentes: Elapidae)
Abstrak: Papua white snake, Micropechis ikaheka, has been distingushed into two subspecies M.i. ikaheka and M.i. fasciatus. However, due to lack of data on their morphology, distribution and ecology, both subspecies often ignored in scintific discussions and refers only byas , Micropechis ikaheka. This study was designed to document the differences between M.i. ikaheka and M.i fasciatus by using scales characteristics and reproductive organ or hemipenes. The study also examine, zoogeography, habitat, diet and cannibalism of both subspecies to better understanding the the ecology of one of the most venomous snakes in the world. This study consists of three topics with method and also different in the size samples, respectively. The first study is the histology and microtopography of the skin were studied using paraffin method and Scanning Electron Microscope (SEM). The second is the hemipenis were examined by following Myers and Cadle (2003), and Zaher and Prudente (2003). The third is the abdominal surgery was carried out to document diet type and the investigate phenomenon of cannibalism in the snake. Specimens for this study came from the collection from Museum Zoologicum Bogoriense (MZB) and Universitas Negeri Papua’s Laboratory (LZU). The research result also indicated that the markers of skin and hemipenis described the same structure and microornamentation in all M. ikaheka groups being compared. Based specimens examined morphological descriptions do not s support the further differentiation in Micropechis. In short, two markers that used in this study could not sufficiently indicate the differences in the level of species and subspecies of M. ikaheka. The study, however, were able to delineate zoogeography and skin color patterns, which fall into four groups: M. i. ikaheka; M. i. fasciatus. M. i. ssp. “intermediate”; and M. i. ssp “black”. This study also revealed that color variations did not overlap in their geographic distribution. It is therefore, it suggested that environmental factors may contribute to the skin color variations. It also assumed that habitat discontinuous and biogeography factors may also cause the loss of the connection between the original populations (vicarians) or follow colonization events (dispersal). The examined of 22 stomach contents of M. ikaheka shows this species is carnivorous, and prey on vertebrates such as amphibians, fish, reptiles, and Mammals. These snakes are opportunistic predators since they prey on all that can be captured, but mainly reptiles (61.5%), followed by mammals and fish (both 15.4%), and amphibians (7.7%). Although categorized as terrestrial animal, the diet study showed that M. ikaheka snakes often go into the water to hunt for fish (the sample from Yapen island), including eel (the sample from Aru island). Based on prey items indentified, there is evidence that M. ikaheka is cannibal. At this time, there still no record on reason for cannibalism, but it is assumed that cannibalism was due to competition between populations and means to control population.
Keyword: geographic variation, white snake, papua