Judul: Ekspansi Kueri pada Sistem Temu Kembali Informasi Berbahasa Indonesia Menggunakan Thesaurus
Abstrak: Query expansion is a common technique for fixed query in order to yield a better information retrieval result. Using a thesaurus is a way for fixed query. Thesaurus is a dictionary of words and terms which are collected and filtered by correlation of meaning of the word, like synonim, antonim, hyponim, and hypernim. This research is intended to analyze the effectivity of query expansion using thesaurus Global Analysis Method. There are a thousand agricultural documents and 93 medical plants documents. The research used Tf-Idf as a weighting method. The result of system performance which were used in this research is good with average precision of 53% for agricultural document and 76% for medical plants document using thesaurus query expansion. The maximal result that the thesaurus could gain is by using two-word length query. Query expansion method using thesaurus has a better result than the one using 2-language dictionary and pseudo relevance feedback document segmentation. The query length and the taking of some number of word group in thesaurus will affect the result of information retrieval.
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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: Pelapisan Hidroksiapatit (HAp) Pada Permukaan Logam Stainless Steel 316L Dengan Metode Deposisi Elektroforesis (EPD)
Abstrak: Telah dilakukan penelitian Ullluk meiapisi pennukaan logam sfainless steel 316 L. oleh material hidroksiapatit dengan rnetode deposisi elektroforesis. Hidrokiapatit dibuat dengan Illctode presipitasi, dari hasil kalsinasi cangkang telur pada suhu JOaOoe selama 5 jam dan (NH4hHP04 . Pemilihan logam stainless steel (S8) didasarkan pada sifat ketahanan korosi yang baik, kadar illlpuritas rendah, dan mudah dibentuk. Penelitian dilakukan dengan rnelarutkan hidroksiapatit pada etanol ditambah trietanolamin sebagai dispersan. Konsentrasi Cal P yang digunakall pada saat presipitasi yaitu 0,3/0,16, Spektra infra merah menunjukkan bilangnya karbonat pada sam pel hasil presipitasi yang dipanaskan pad a suhu 900°C. Pola difraksi sinar X untuk hasil presipita:;i yang c1ipanaskan pad a suhu 900°C, menunjukkan fasa yang terbentuk adalah hidroksiapatit. Pola dilj'aksi setelab coaling menul1ujukkan adanya fasa hidroksiapatit dan base metal yaitu logam SS. HasH uji mikrostruktur menlll~ukkan, diantara penggunaan variabel tegangan 30 V; 60 V dan 90 V selama 1,2, dan 3 menil pada saat coating, penggunaan variabel tegangan 60 V selama 2 menit, menunjukkan hasil peJapisan yang paling merata pada pennukaan logam SS. Sintering dengan suhu sooDe lebih menguatkan peJapisan hidroksiapatit pada permukaan logam dibandingkan dengan sintering pacta suhu 250°C.
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