Judul: Train Scheduling Using Integer Linear Programming.
Abstrak: Karya ilmiah ini memberikan formulasi masalah penjadwalan kereta api menggunakan model pemrograman linear integer. Penjadwalan kereta api tersebut didasarkan pada jalur tunggal yang menghubungkan antar stasiun. Formulasi yang dibangun bertujuan meminimumkan keterlambatan serta menjamin bahwa tidak ada kereta api yang mengalami tabrakan baik searah maupun berlawanan arah. Input model berupa jadwal keberangkatan kereta api yang direncanakan (aktual), sedangkan outputnya berupa jadwal keberangkatan dan kedatangan kereta api yang faktual.
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Judul: Optimasi Biaya Operasional Kereta Api dalam Sistem Loop Line Menggunakan Pemrograman Integer Taklinear
Abstrak: High demand for transportation that causes passenger’s congestion in some stations is one of the main problems faced by PT KAI commuter Jabodetabek (KCJ). This problem can be solved by determining optimal routes and frequencies of the trains. This paper presents a model to determine routes and travelling frequency for each route in order to minimize the total cost. The problem is modelled as a nonlinear integer programming. This model is implemented in Jabodetabek railway network that have been simplified. The parameters of the model include the demand of passengers, the capacity of trains, maximum travelling of train for each route, and operational costs. Developing model is started with identification of all the requirements of the system. All of the requirements then are formulated as linear equalities or inequalities. Ensuring the validity of model is done via solving several scenarios using the model. The solution of the model is obtained using LINGO 11.
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Judul: Distribution and Diversity of Ectoparasite Mites on Geckos in Indonesia
Abstrak: Data on the diversity and dispersal of parasitic mites on house geckos in Indonesia are very scarce. In this work, the distribution and diversity of mites living on three species of house geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii collected throughout Indonesia, has been elaborated. Geckos and mites were captured and immediately preserved in 70% ethanol. Whole mount of the mites was prepared by clearing in lactophenol followed by mounting on polyvinyl lactophenol solutions. The SEM preparation was conducted to examine the detail morphological characters of the mites. The results showed that among 448 individuals of geckos, 221 geckos were infected by Geckobia mites. Prevalences of C. platyurus, H. frenatus, and H. garnotii infested by mites were 14.8%, 50.69%, and 79.6%, respectively. Three different spesies of Geckobia (G1, G2, and G3) could be differentiated; and based on similarities of their morphological characters to ones described in published literatures, Geckobia G2 is Geckobia glebosum and Geckobia G3 is Geckobia bataviensis while G1 could not be identified to the species level. The highest mean intensity of Geckobia G1 infestation was found on H. garnotii (I=7.0), G. glebosum infestation on H. frenatus (I=3.5), and G. bataviensis infestation on H. garnotii (I=11.8). In general, C. platyurus was infested by the least number of mites. Geckobia G1 were found living on the skin folds on the claws, G. glebosum were found mainly on the body and thigh, and G. bataviensis were found on almost all parts of the host’s body. Geckobia mites are distributed randomly throughout Indonesian Archipelago, following the pattern of distribution of their hosts. So it is concluded that Geckobia G1, G. glebosum, and G. bataviensis are sympatric.
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