Judul: Optimisasi Penjadwalan Pesawat Terbang Menggunakan Integer Linear Programming: Studi Kasus Maskapai PT Citilink
Abstrak: Salah satu aspek yang terpenting dalam manajemen suatu maskapai penerbangan adalah menentukan jadwal dan rute penerbangan bagi setiap pesawat guna memenuhi kebutuhan pesawat terbang bagi setiap segmen penerbangan dalam seluruh jadwal penerbangan yang sudah ditentukan maskapai penerbangan. Menurut Bazargan (2004) ada empat tahap proses dalam manajemen perencanaan penerbangan, yaitu i) penjadwalan penerbangan, ii) penugasan armada, iii) penentuan rute pesawat terbang, dan iv) penjadwalan kru. Dalam proses pembuatan jadwal dan rute penerbangan bagi setiap pesawat terbang dilakukan melalui tahap penugasan armada dan penentuan rute pesawat terbang. Tahap penugasan armada menentukan jumlah pesawat untuk masing-masing armada yang akan digunakan, serta menentukan base untuk setiap pesawat. Tahap penentuan rute pesawat terbang menentukan rute dan waktu penerbangan untuk setiap pesawat. Karya ilmiah ini menyajikan model optimisasi masing-masing untuk tahap penugasan armada dan penentuan rute pesawat terbang dalam bentuk model integer linear programming (ILP). Model ini diimplementasikan pada kasus maskapai PT Citilink yang memiliki 254 penerbangan pada 24 kota di Indonesia. Hasil implementasi model memberikan jumlah minimum pesawat sebanyak 48 unit yang terdiri dari 41 unit Air Bus 320, 6 unit Boeing 737-300, dan 1 unit Boeing 737-400, dengan total biaya operasional minimum sebesar Rp 14 214 981 000.
Keyword: citilink, integer linear programming, penerbangan, penjadwalan pesawat, penugasan armada, rute pesawat

Judul: Optimasi Penjadwalan Armada Pesawat Terbang
Abstrak: One of the common issues faced by airline companies relies on fulfilling passenger demands for Origin-Destination (O-D) routes using all fleet types. This paper presents an optimization model to determine fleet assignment for each flight route in order to minimize total costs. The total costs consist of the operating cost and passenger spill cost. The model is considered as an integer linear programming which is further implemented within the Citilink airlines schedule, and was solved using software Lingo 11.0. The model produced a fleet assignment in order to fulfill demand for all O-Ds with minimum cost.
Keyword: fleet assignment, integer linear programming, optimization

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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