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: 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: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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