Judul: Ekspansi Kueri pada Sistem Temu Kembali Informasi dengan Tesaurus dan Pendekatan Boolean
Abstrak: This research implements and evaluates the implementation of automatic query expansion with synonyms and antonyms derived from thesaurus with boolean approach. The research was conducted because query expansion in the previous research by Pancawan using intersection weight required a long time. This research used 2095 documents and 30 queries. Using one synonym produced the best performance with an average F1 of 0.06376 in average time of query expansion 5.256 seconds, while the previous research produced an average F1 of 0.06385 in 23.451 seconds. Using one antonym on this and previous research produced the same average F1 of 0.06651. However, the average time required for the query expansion in this research was 1.916 seconds, only half of the previous research that took 4.890 seconds. From the evaluation result of the document retrieval comparison, this research obtained a similar performance in less time.
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Judul: Ekspansi Kueri pada Sistem Temu Kembali Informasi dengan Tesaurus dan Bobot Irisan
Abstrak: Query expansion is a technique to change the intial query from user in order to improve and optimize result of a retrieval system by getting more relevant documents. Thesaurus is a collection of synonyms and antonyms that can be utilized to get additional terms in query expansion. We propose a method to choose additional terms for query expansion based on insersection betweeen results from original query and results from expanded query. We experiment with synonyms and antonyms using 2095 documents and 20 queries that we made for this research. To make these queries, we use words that are generally different from the words that are contained in the document collection. The result of this research shows that the use of query expansion can improve the performance of the retrieval system in getting more relevant documents. It also shows that the use of two synonym terms result in the best query expansion, retrieving 98.1% relevant documents with an average precision of 0.252, while the use of an antonym is only able to retrieve 86.9% relevant documents with an average precision of 0.173.
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Judul: Stabilization of Protein by Lactose during Storage in the MPC 85 System
Abstrak: Milk protein is the most valuable component and its stability is important during processing and storage. The stabilization is influenced by moisture and position of milk powder. It is assumed that lactose can acts as stabilizer of protein (protect from protein unfolding). The phenomenon of this stabilization was studied at three water activity (aw 0.23,0.54 and 0.75), with low concentration of lactose addition (5, 15 and 30%) during 6 weeks. Sample preparation'of MPC powders and equilibration at different relative humidity was conducted before storage. Analysis of MPC to investigate the influence of lactose in protein stabilization include solubility test, glass transition (Tg) by TMCT (Thermal Mechanical Compression Test), secondary protein structure (FTIR), and T2 relaxation (NMR) to measure the protein water interaction in MPC85 system. The role of lactose to retain the change of stability during storage can be observed clearly at aw 0.54. In this condition, the rate of solubility and Tg decreasing/week and also the rate of increasing of T2 short proportion/week can be retained by lactose adding. The capability of lactose to retain the rate of change of solubility, Tg and T2 short proportion cannot be observed at low water activity (aw 0.23) because of the small amount of water in the system. At aw 0.75, lactose adding c annot retain the change of stability due to very higher water content and lactose coystallization. Evidence from FTIR suggested that this reduction in solubility was not directly linked to major conformational changes within protein structures.
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