Judul: Proyeksi Penduduk Indonesia Menggunakan Model Deterministik dan Model Stokastik Kelahiran dan Kematian
Abstrak: Proyeksi penduduk adalah perhitungan jumlah orang yang diharapkan untuk hidup di masa mendatang dengan melihat jumlah penduduk saat ini. Proyeksi penduduk dibuat sebagai dasar untuk mengantisipasi hal-hal yang dapat mengubah proses dan kecenderungan penduduk saat ini. Di samping itu, proyeksi penduduk juga dapat digunakan untuk mengantisipasi kemungkinan perubahan tren yang diakibatkan oleh perubahan secara tiba-tiba dari faktor-faktor yang berkaitan erat dengan variasi demografi. Karya ilmiah ini menyajikan proyeksi penduduk Indonesia melalui dua pendekatan. Pendekatan pertama adalah dengan model deterministik, yaitu model pertumbuhan linear, geometrik, eksponensial, hiperbolik, dan logistik. Pendekatan kedua adalah dengan model stokastik kelahiran dan kematian, yaitu model kelahiran murni, model kelahiran dan kematian, tanpa dan dengan migrasi. Berdasarkan data sensus penduduk Indonesia tahun 2010 dibuat proyeksi penduduk Indonesia tahun 2015-2035. Dibandingkan dengan data proyeksi yang dilakukan oleh Badan Pusat Statistik, proyeksi dengan model stokastik kelahiran dan kematian dengan migrasi mampu memberikan hasil yang lebih baik daripada model yang lain.
Keyword: deterministic models, population projection, stochastic models of birth and death

Judul: Proyeksi Penduduk dengan Proses Kelahiran dan Kematian
Abstrak: A population projection is a scientific calculation based on certain assumptions of births, deaths, and migration. These three components determine the size of the population in the future. The aims of this study are to develop population projection model using birth and death process and to apply the model to Indonesian population data. This study uses four steps of modelling process. First, we develop a model of birth and death process with migration. Second, we verify the model using 1990 Indonesian population data and compare the result with the real data. Third, using the model we estimate population projection for the years 2000-2025 based on Indonesian population data of the year 2000 and compare the result with population projection for years 2000-2025 by BPS. Finally, we estimate population projection for years 2010-2035 based on Indonesian population data of the year 2010. The advantage of this model is that we can give the confidence interval of the estimate besides the value of estimation. The difference between our projection based on 1990 Indonesian data and the real data is below 10%, and the difference between our projection based on Indonesian data of the year 2000 and projection by BPS is less than 6%.
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Judul: Pengaruh penggunaan bahan pengokdidasi terhadap mutu kulit samoa pada penyamakan  kulit menggunakan minyak biji karet
Abstrak: Leather tanning using oil as the tanning agent has disadvantages, such as the time of oxidation which is takes a long time in about 9 days. Using sodium percarbonate as oxidizing agent in the tanning process, known to shorten the time into two days, eventhough, the high cost of sodium percarbonate was being obstacle in its use. Other oxidizing agents such as hydrogen peroxide and sodium hypochlorite may have the same function with sodium percarbonate, i.e. acceleration of the oxidation process. The objectives of this research were to investigate the influence of the oxidizing agents and their concentrations on the quality of chamois leather and to determine the best combination of type and concentration of oxidizing agents in the production process of chamois leather. The main research consisted of leather tanning using rubber seed oil, oxidation in drum with three types and concentrations of the oxidizing agents, measurements of physical, chemical and organoleptic properties of chamois leather. The results showed that the three types of the oxidizing agent could be used to accelerate the oxidation process in the manufacture of chamois leather. The type of oxidizing agent gave significant effect on shrinkage temperature, ash content, colour and odour of leather, while the oxidizing agent concentration significantly affected the colour and odour of chamois leather. The treatment of experiment selected based on the quality of leather was sodium hypochlorite with the concentration of 2%. Tanning by using this treatment produced chamois leather with the properties as follows: shrinkage temperature of 75.2oC, tensile strength of 30.5 N/mm2, elongation at break of 134.3%, tear strength of 86.2 N/mm, water absorption of 265% (2 hours) and 286% (24 hours), pH 6.56, oil content of 8.71%, ash content of 1.12%, softness of 8-9, colour of 7-8 and odour
Keyword: Hydraulic pressing, Oxidizing agent, Sanitizer