Judul: Temporal Entity Tagging untuk Dokumen Bahasa Indonesia
Abstrak: One of the processes in document pre-processing is providing identifier tags called Named Entity Tagging. This research aims to implement a temporal entity tagging in Indonesian language documents with rule-based method. Temporal expressions are marked with DATE tag and the temporal value of the expression. Temporal expression comprise explicit expression, implicit expression, and event expression. The rules were obtained by analyzing temporal expressions in 100 Indonesian documents. There are 40 derived rules implemented in this system over 341 temporal expressions in the document. The system could find all of the temporal expressions consisting of 150 explicit temporal expressions, 155 implicit temporal expressions, and 36 event expressions. Also, the evaluation was conducted on 34 other documents. The system can correctly identify as many as 122 of 129 temporal expression contained in the additional documents. The system has achieved an accuracy of 100% for the 100 initial documents and 94.57% for the 34 test documents. Thus, rule-based identification of temporal entities for Indonesian performs well.
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Judul: Temporal Question Answering System Bahasa Indonesia
Abstrak: Time is an important dimension in information retrieval. Temporal expressions describe time information embedded in the documents. Therefore, extraction and normalization of temporal expressions from documents are crucial. In this research, a question answering system is implemented for temporal information processing from documents in Indonesian language based on four types of temporal question beginning with question words such as siapa (what), kapan (when), di mana (where), and berapa (how many). Implicit time references in document are first normalized and tagged manually into explicit time references. Complex temporal question is divided into simpler questions by using temporal signal detection for specific sequence of events. In order to obtain answer candidates, heuristic weighting is performed on the top passages. Answer extraction is performed using the smallest distance between query and answer candidates. A corpus containing 100 documents and 80 queries is used in this research. Answer evaluation is based on three criteria, namely, Right, Wrong, and Unsupported. The questions are used to evaluate the results of BM25 and Proximity ranking modes. The evaluation for simple temporal questions (Type 1 and 2) using BM25 and Proximity gave the same results at 85% Right answers for Type 1 and 75% for Type 2. The results for complex temporal questions (Type 3 and 4) indicated good performance. The best results were obtained by BM25 at 95% Right answers for Type 3 and 75% for Type 4, while using Proximity resulted in 85% Right answers for Type 3 and 80% for Type 4. We also used our corpus on a nontemporal question answering system by Umriadi in 2011. The results are 60%, 55%, 60%, and 40% Right answers for Type 1, 2, 3, and 4, respectively, much lower than our temporal question answering system. Therefore, temporal expression extraction and temporal signal identification are particularly important for handling questions containing temporal information. Our system is able to identify and answer the temporal questions in Indonesian language.
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Judul: Growth, Concentration Chlorophyll-a, and Structure of Macroalgae Gracilaria edulis in the Culture Media Containing Copper
Abstrak: The physiological responses (specific growth rate, concentration of chlorophyll-a, morphological and anatomical structure of the vegetative cells) of the marine macroalga Gracilaria edulis at the different concentrations of copper (0.01 as control, 0.04, 0.06 and 0,5 ppm) delivered continuously for 28 days under controlled laboratory conditions were investigated. Result showed that the degree of copper toxicity depends on both factor the concentration and exposure time. Copper concentration and day of exposure decreased significantly the specific growth rate (SGR) of the Gracilaria edulis but only 0,5 ppm Cu decreased the chlorophyll-a content when compared to control. Of the various physiological end points measured, growth proved to be the most sensitive response than chlorophyll-a with reductions in specific growth rate (SGR). The reason for this could be related to a greater sensitivity of the enzymes involved in growth than those related to chlorophyll-a or a greater energy needs to maintain cellular integrity and metabolic processes under sublethal Cu stress. In all cases, the main effect on vegetative cells were structure changes in cortex and subcortex cells, compared to control, macroalgae exposed to copper showed depigmentation and blending in the lateral branches, heavy staining of the cell wall and severe damage of cell membrane, while the mucilage and the cell walls was densely fibrillar, thick and heavily stained, the cortex cell was clearly vacuolated, the presence of endophytic on the cell wall and endophytic spores in the mucilage. The presence vacuoles should be related to a metal immobilization mechanism, minimizing the Cu toxicity for cells. The epiphytic bacteria can act as a biofilter diminishing the availability of Cu for macroalgae accumulation.
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