Judul: Ukuran kemiripan BM25 pada Model Ontologi Mesin Pencari Produk Online Shop
Abstrak: Penelitian ini membangun mesin pencari berbasis Apache Solr menggunakan informasi hierarki dari ontologi untuk mengekspansi query yang diberikan oleh pengguna. Mesin pencari ini menggunakan BM25Similarity dengan memodifikasi tuning parameter (k1 dan b) yang ada di dalamnya. Mesin pencari ini menggunakan 76 518 data produk milik Blibli.com. Hasil evaluasi terhadap mesin pencari ini menunjukkan bahwa BM25Similarity yang telah dituning (k1 = 2.0 dan b = 1.00) memberikan kinerja yang relatif lebih baik dibandingkan DefaultSimilarity (model Boolean dan ruang vektor) untuk evaluasi dengan menggunakan query uji pada pencarian produk online shop Blibli.com. BM25Similarity yang telah di-tuning pada penelitian ini dapat meningkatkan nilai MAP sebesar 0.0138.
Keyword: Apache Solr, BM25, mesin pencari, online shop, ontologi, tuning parameter

Judul: Pengembangan mesin pencari pada online shop menggunakan pemodelan dokumen ontologi produk
Abstrak: Mesin pencari pada online shop memegang peranan penting sebagai fasilitas untuk menemukan produk yang dibutuhkan oleh konsumen. Relevansi antara query masukan dengan hasil yang ditampilkan oleh sistem terkadang menjadi permasalahan disaat mesin pencari tidak dapat merepresentasikan pengetahuan dari data pada dokumen. Penelitian ini mengajukan sebuah model ontologi untuk mesin pencari. Fokus dari penelitian ini adalah melakukan pemodelan ontologi pada data produk milik e-commerce dan menerapkannya untuk modifikasi pada query. Penelitian ini mengukur performa mesin pencari dengan membandingkan pencarian menggunakan model ontologi dan model relasional database. Pada penelitian ini diujikan 20 query menggunakan Solr pada 76,518 data produk milik e-comerce Blibli.com. Hasil evaluasi menunjukan bahwa mesin pencari menggunakan model ontologi lebih baik dibandingkan dengan tanpa ontologi. MAP (mean average precision) search engine menggunakan model ontologi sebesar 0.94.
Keyword: e-commerce, ontology, query modification, search engine

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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