Judul: Kajian spektroskopi impedansi listrik pada Udang Galah (Macrobrachium rosenbergii) berformalin
Abstrak: Electrical impedance spectroscopy (EIS) is one of the techniques used to detect the electrical properties of biological materials. All biological materials naturally have ions that can be identified electrical properties, so many researchers who have developed a technique of identifying and assessing the electrical properties. This research aims to study the electrical properties of the shrimp with formaldehyde and without at a frequency of 1 to 1000 KHz, which is stored for six days in free air at a room temperature and determine the effect of shelf life, the influence of the distance between the electrodes and the influence of the concentration of formaldehyde on the electrical properties by analyzing Impedance, Resistance, Inductance, Capacitance and Q factor. The resulting electrical properties show that the farther distance causes the impedance increases. Furthermore, although there is no standard that distinguishes between shrimp formalin with formalin not consistently, the results of this electricity is able to demonstrate a decrease in the quality of shrimp, membrane damage, and tissue damage shrimp after cell death.
Keyword: Bogor Agricultural University (IPB), shrimp., frequency, formaldehide, gap, electric

Judul: Analisis Target Strength Udang Galah (Macrobrachium rosenbergii De Man) Menggunakan Akustik Split Beam di Sungai Mahakam
Abstrak: Fresh water giant prawn is one of the most abundant species of the high quality economic. Unfortunately water quality condition was changed and it’s feeding ground and nursery ground. This Population declined by indicated fishermen catches were tends to decrease, one of them is fresh water giant prawn. On the other hand, information of the spatial dispersal is limited and the identification of fresh water giant prawn still used by visual. This research tried to estimate target strength value of fresh water giant prawn influenced by biological factors associated with the ontogeny (total length, carapace length and weight) and physiology (gravid and non-gravid). The research was conducted by using stationary position and controlled the acoustic method in Mahakam River, East Kalimantan. The hydroacoustic instrument used was Simrad EY 60. Five samples of prawns were measured for memories 50 kB and 200 region on echogram each of. The variables of ontogeny were analyzed by simple regression model, principal component analysis and z test. The results showed that target strength of each samples were -64,45; -65,30; -65,15; -65,21; and -55,27 dB, respectively. The regression (r2) between target strength with carapace length were 0,9103; total length 0,4704 and weight 0,3633, respectively. Calculation of principal component analysis (PCA) is used the fourth variable (target strength, total length, carapace length and weight) reduced to 2 variables. Then two new variables can explain 99.8% of the total variability of the four variables. PCA biplot graph shows that have a carapace length greater closeness when compared with the other variables. Samples 2, 3, and 4 have similar characteristics, but samples 1 and 5 do not have similar characteristics with each other. Z test results are tcalculate> ttabel then H0 rejected. This result show the sample gravid and non-gravid are not the same, because the t value falls in the region of the right of criticism. The gravid conditions suspected exerts a greater influence on the value of the target strength than the conditions non-gravid. The conclusion are value of the target strength on fresh water giant prawn influenced by the length of the carapace (ontogeny) and gravid condition (physiology).
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Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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