Judul: Penjadwalan Mata Pelajaran di Sekolah: Studi Kasus di SMPIT Nurul Fajar Bogor
Abstrak: Scheduling is one of the problems faced by many institutions including schools. However, the conventional scheduling is often sub-optimal. In this work, the scheduling problem is modeled mathematically using integer programming approach. In this paper the problem of scheduling of courses was formulated into integer nonlinear programming. The model is then implemented to solve the courses scheduling problem in SMPIT Nurul Fajar School Bogor. The computer software LINGO 11.0 was used to obtain optimal solutions in the form of courses and satisfying all constraints of subject and teachers’ schedules.
Keyword: Bogor Agricultural University (IPB), school., courses, scheduling, integer nonlinear programming

Judul: Courses Scheduling Problem Case Study in SMA  Plus Liwaul Furqan Bogor
Abstrak: Penjadwalan merupakan masalah umum yang sering dijumpai di bidang ilmu matematika. Salah satu model matematika yang dapat digunakan untuk menyelesaikan masalah penjadwalan adalah Integer Linear Programming. Tujuan dari penelitian ini adalah menentukan model matematika untuk menyusun jadwal mata pelajaran dengan meminimumkan bobot mata pelajaran berdasarkan prioritas mata pelajaran tertentu di sesi awal terhadap periode waktu, kemudian mengimplementasikan model tersebut pada masalah penjadwalan mata pelajaran di SMA Plus Liwaul Furqan Bogor. Masalah penjadwalan mata pelajaran di Sekolah Menengah Atas (SMA) Plus berkaitan dengan guru, mata pelajaran, kelas, dan sesi waktu. Penjadwalan mata pelajaran ini diselesaikan dengan bantuan software LINGO 11.0. Hasil dari penelitian ini adalah solusi optimal berupa jadwal mata pelajaran yang memenuhi semua kendala yang diinginkan. Kata kunci: integer linear programming, mata pelajaran, penjadwalan, SMA Plus, Scheduling is a common problem that is often encountered in the field of mathematics. One of the mathematical models that can be used to solve scheduling problems is Integer Linear Programming (ILP). The purpose of this study is to determine a mathematical model to compile a schedule of subjects by minimizing the weight of the subjects based on the priority of certain subjects in the initial session against the period, then implementing the model in the subject scheduling problem at SMA Plus Liwaul Furqan Bogor. Subject scheduling issues in Senior High School (SMA) Plus relate to teachers, subjects, classes, and time sessions. The scheduling of these subjects is completed with the help of the LINGO 11.0 software. The results of this study are the optimal solution in the form of a schedule of subjects that meet all the desired constraints. Keywords: courses, integer linear programming, schedulling, SMA Plus
Keyword: courses, integer linear programming, schedulling, SMA Plus

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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