Judul: Pembuatan Result Snippet pada Mesin Pencari Berbahasa Indonesia dengan Menggunakan Pseudo-Relevance Feedback
Abstrak: A search result snippet is a quick excerpt from a document retrieved by a retrieval system (search engine) that explains the existence of the keywords entered by a user. Snippets generated by a search engine must be able to provide enough information so that a user can make decision on whether or not a document is relevant based on his/her information needs. This study implements pseudo-relevance feedback techniques for selecting the sentences to be displayed as a snippet and evaluates the accuracy of the snippet generated by the system. Application of pseudo-relevance feedback in this study resulted in an accuracy of 90.71% from the documents that are considered relevant.
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Judul: Pseudo-Relevance Feedback on Retrieval Using Sentence Segmentation
Abstrak: A very large amount of information has stimulated the development of search engine to help users in finding information they need. To retrieve information that relevant to the user’s needs, users should be able to formulate queries correctly. Pseudo-relevance feedback is an automatically local analysis technique for improving queries. This technique takes the top n-ranked documents and takes the top x-ranked terms from relevant documents. The purpose of this research is to implement query expansion with pseudo-relevance feedback using sentence segmentation. There are two groups of documents, 1.000 agriculture documents and 93 medicine plants documents which are used. The test result shows that the use of medicine plants documents is better than agriculture documents. This is due to agriculture documents have a high enough similarity between documents. The performance of information retrieval with pseudo-relevance feedback using sentence segmentation gave good result with around 89% average precision for medicine plants documents and 56% for agriculture documents.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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