Judul: Determination of Premium on Reversionary Annuity with Two Dependent Future Lifetimes using Markov Model
Abstrak: Pada umumnya, premi untuk asuransi multilife ditentukan menggunakan asumsi saling bebas. Namun, asumsi ini tidak realistis, contohnya untuk pasangan suami istri. Tujuan dari karya ilmiah ini adalah menentukan premi tunggal bersih pada reversionary annuity dengan memperhitungkan kebergantungan masa hidup di antara pasangan suami istri menggunakan batas Frechet-Hoeffding dan model Markov, membandingkan premi tunggal bersih yang memperhitungkan kebergantungan dengan premi yang menggunakan asumsi saling bebas, serta memeriksa pengaruh nilai parameter kebergantungan terhadap premi tunggal bersih. Penghitungan didasarkan pada Tabel Mortalitas Indonesia (TMI) IV mengikuti sebaran Makeham. Hasil penghitungan menunjukkan bahwa dengan model Markov nilai premi tunggal bersih lebih rendah daripada dengan model standar yang menggunakan asumsi saling bebas. Nilai premi tunggal bersih akan menurun seiring meningkatnya nilai parameter kebergantungan masa hidup lakilaki terhadap istrinya yang masih hidup. Nilai premi tunggal bersih akan meningkat seiring meningkatnya nilai parameter kebergantungan masa hidup perempuan terhadap suaminya yang masih hidup. Nilai premi tunggal bersih akan menurun seiring meningkatnya nilai parameter kebergantungan masa hidup perempuan terhadap suaminya yang sudah meninggal., In general, premiums for multilife insurance are determined by assuming the independence of the future lifetimes of insured persons. However, this assumption is unrealistic, such as for husbands and wives. The aims of this paper are to determine the net single premium on reversionary annuity by taking into account the dependence of the future lifetimes of husbands and wives using the FrechetHoeffding bounds and Markov model, to compare the net single premium that takes into account the dependence with the premium using independent assumption, as well asto examine the effect of the value of dependence parameters on the net single premium. The calculation is based on Indonesian Mortality Table IV following the Makeham distribution. The calculation results show that with Markov model the net single premium value is lower than the standard model that assumes independence. The parameter net single premium value will decrease as the value of man’s lifetime dependency parameter towards his wife who is still alive increases. The parameter net single premium value will increase as the value of woman's lifetime dependency towards her husband who is still alive increases. The parameter net single premium value will decrease as the value of woman's lifetime dependency parameter towards her deceased husband increases.
Keyword: Frechet-Hoeffding bounds, lifetime dependency, Makeham distribution, Markov model, reversionary annuity

Judul: Calculation of Premium for Life Insurance and Life Annuity Policies when Interest Rates are Modeled Using Moving Average
Abstrak: Mengikuti program asuransi jiwa adalah suatu usaha yang dapat dilakukan untuk meminimumkan risiko keuangan yang diakibatkan oleh kematian. Ketika seseorang mengikuti program asuransi, orang tersebut memiliki kewajiban untuk membayar sejumlah uang yang disebut premi. Salah satu faktor penting yang menentukan besar premi yang harus dibayar adalah tingkat bunga yang digunakan. Penelitian ini bertujuan untuk membandingkan besar premi tunggal bersih beberapa polis asuransi jiwa dan anuitas hidup saat tingkat bunga dimodelkan dengan proses moving average dan saat tingkat bunga dimodelkan dengan model independent and identically distributed. Data yang digunakan adalah data tingkat bunga BI 7-day (Reverse) Repo Rate periode April 2016 sampai April 2021 dan Tabel Mortalitas Indonesia IV. Berdasarkan hasil penghitungan, premi tunggal bersih yang dihasilkan saat tingkat bunga dimodelkan dengan proses moving average lebih besar daripada saat dimodelkan dengan model independent and identically distributed., Joining a life insurance program is an effort that can be done to minimize the financial risk due to death. When someone joins an insurance program, that person must pay a certain amount of money so-called premium. One of the important factors that determine the amount of premium to be paid is the interest rate used. This study aims to compare the net single premium of several life insurance and life annuity policies when the interest rate is modeled using a moving average process and when the interest rate is modeled using an independent and identically distributed model. The data used are BI 7-day (Reverse) Repo Rate for the period April 2016 to April 2021 and the Indonesia Mortality Table IV. Based on the calculation, the net single premiums produced when the interest rate is modeled using a moving average process is higher than those when the interest rate is modeled using an independent and identically distributed model.
Keyword: interest rate, life annuity, life insurance, moving average, net single premium

Judul: Heterologous Expression Of Endo-Β-Xylanase From Bacillus Pumilus Strain Bcrs-01 In Escherichia Coli.
Abstrak: Xylanases are glycoside hydrolase family 11 which depolymerise xylan in the plant cell wall, the most excessive form of hemicellulose. Endo-β-xylanases (EC 3.2.1.8) are most important to breakdown β-1,4-glicoside bond of xylan to produce disaccaride xyloolygosaccaride (XOs) and xylose (monomer). Bovine rumen fluids have potential to obtain endo-β-xylanase produced of bacteria. The objectives of this study were to obtain xylanase producing bacteria and to express xynA gene encoding endo-β-xylanase from bacterium in Escherichia coli. Twenty nine isolate bacteria have been succesfully isolated from bovine rumen fluid in agar medium containing birchwood xylan. Isolate BCRS-01 bacterium was previously screened for the high production of xylanase. Based on 16S rRNA gene sequence analysis, BCRS-01 showed high similarity (99%) to Bacillus pumilus (accession number NR043241). The crude xylanase had optimal activity at 55oC, pH 7.0. Furthermore, the crude xylanase exhibited broad pH stability from 4.0 to 10.0 and remained more than 60% and 40% of its activity after incubation at pH 4.0 until 10.0, respectively for 60 min. It also showed a stability at temperature 25-50oC since it retained 80% and 50% of its activity when incubated at 50oC or 30 and 60 min, respectively. The xylanase activity was strongly inhibited by Ca2+ and Cu2+ at concentration 10 mM, and as little as 1 mM for Mn2+. Therefore, this xylanase has potentially used as additive feeds in animal feed industry. The DNA sequence xynA gene encoded endo-β-xylanase was amplified and cloned into the expression vector pET-15by under the control of T7 promoter. The recombinant protein had succesfully expressed in Escherichia coli BL21 (DE3) pLysS. A protein recombinant of approximately, 26.7 kDa was observed on the SDS-PAGE analysis. Crude extract of recombinant endo-β-xylanase demonstrated activity of enzyme at 56 U mL-1 using birchwood xylan as a substrate at 55oC for 10 min.
Keyword: Bacillus pumilus, bovine rumen fluid, endo-β-xylanase, heterologous expression.