Judul: Strategi Pengembangan Usaha Perkebunan Kelapa Sawit pada PT Perkebunan Nusantara I Langsa di Provinsi Aceh
Abstrak: PT Perkebunan Nusantara I merupakan perusahaan milik negara yang mengoperasikan kegiatan di dalam industri perkebunan kelapa sawit yang sangat ketat baik dalam persaingan maupun permintaan, sehingga perusahaan memerlukan strategi pengembangan bisnis untuk mengatasinya. Penelitian ini bertujuan untuk merumuskan dan merekomendasikan strategi pengembangan usaha yang tepat untuk PT Perkebunan Nusantara I dengan mempertimbangkan lingkungan internal dan lingkungan eksternal. Alat analisis yang digunakan adalah matriks IFE, matriks EFE, matriks IE, matriks SWOT, dan matriks QSP. Matriks IFE dan EFE menunjukkan bahwa kondisi internal perusahaan dan kondisi eksternal yang baik. Matriks IE menunjukkan bahwa perusahaan berada pada kuadran lima. Formulasi alternatif strategi yang dibuat menggunakan matriks SWOT menghasilkan tujuh alternatif strategi. Prioritas strategi yang dihasilkan menggunakan matriks QSP yaitu menghasilkan produksi kelapa sawit sesuai atau mendekati RKAP produksi perusahaan.
Keyword: perkebunan kelapa sawit, strategi pengembangan, IFE, EFE, IE, SWOT, QSP

Judul: Strategi Pengembangan Usaha Perkebunan Kelapa Sawit pada PT Perkebunan Nusantara 4 Medan Sumatera Utara
Abstrak: Indonesia is an agricultural country, which the agricultural sector is as one of the biggest sector that contribute for the national GDP. Plantation is a part of agricultural sector that has palm oil as one of the biggest commodity of it. The high demand of palm oil from domestic and also abroad is one of the opportunity for many palm oil companies in Indonesia. Therefore, business development strategy is needed to fulfill the high demand of palm oil to catch the opportunity. Internal Factor Evaluation (IFE) and External Factor Evaluation (EFE) Matrix are used to identify internal environment (strength and weakness) and external environment (opportunity and threat) that can be used by top management to make a grand strategy. A grand strategy was obtained by I-E Matrix and SWOT Matrix. Finally the best strategies will be chosen by QSPM (Quantitative Strategies Planning Matrix). The result of the analysis showed that the best strategy for PTPN 4 is increasing the efficiency of production in this palm oil plantation firm.
Keyword: QSPM, SWOT, I-E, EFE, IFE, Analysis strategy, Palm oi, PT Perkebunan nusantara 4

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model