249 research outputs found
News recommendations using CF-IDF
Most of the traditional recommendation algorithms are based on TF-IDF, a term-based weighting method. This paper proposes a new method for recommending news items based on the weighting of the occurrences of references to concepts, which we call Concept Frequency-Inverse Document Frequency (CFIDF). In an experimental setup we apply CF-IDF to a set of newswires in which we detect 1; 167 instances of a set of 65 concepts from a domain ontology. The proposed method yields significantly better results with respect to accuracy, recall, and F1 than the TF-IDF method we use as a basis for comparison
Semantic web-based knowledge acquisition using key events from news
Abstract Hermes is an ontology-based framework for building news personalization services, which focuses on news classification and knowledge base updating. The framework also allows for news querying and result presentation. In this paper, we focus on the techniques involved in keeping Hermes' internal knowledge base up-to-date. Essentially, our semi-automatic approach to knowledge acquisition from news is based on ontologies and lexico-semantic patterns
Ontology population from web product information
With the vast amount of information available on the Web, there is an increasing need to structure Web data in order to make it accessible to both users and machines. E-commerce is one of the areas in which growing data congestion on the Web has serious consequences. This paper proposes a frame- work that is capable of populating a product ontology us- ing tabular product information from Web shops. By for- malizing product information in this way, better product comparison or recommendation applications could be built. Our approach employs both lexical and syntactic matching for mapping properties and instantiating values. The per- formed evaluation shows that instantiating consumer elec- Tronics from Best Buy and Newegg.com results in an F1 score of approximately 77%
Modelling the circular polarisation of Earth-like exoplanets: constraints on detecting homochirality
Stars and planetary system
Ion-Exchange Chromatographic Method for the Determination of the Free Amino Acid Composition of Cheese and Other Dairy Products : an Inter-Laboratory Validation Study
Although free amino acids (FAAs) represent a significant component of ripened cheeses and can provide useful information for their characterization, no inter-laboratory validated analytical method exists which allows a reliable comparison of data obtained by different laboratories and the adoption of quality control schemes based on FAA pattern. The objective of the present work was to test the effectiveness of an analytical protocol for the determination of the FAA composition of cheese and to verify the adequateness of this type of analysis for quality control procedures of Grana Padano PDO cheese as well as for research purposes. After an initial test to compare performances of ion-exchange chromatography (IEC) and HPLC techniques, an inter-laboratory collaborative study (seven laboratories, four samples) was organized to validate an IEC method with post-column ninhydrin derivatization and using l-norleucine as an internal standard. Determined amounts of individual FAA ranged from 8 to over 1380 mg/100 g cheese, with relative standard deviation of repeatability (RSDr) ranging from 0.5 to 4.6%, and relative standard deviation of reproducibility (RSDR) ranging from 1.3 to 9.9% for FAA concentrations over 100 mg/100 g. For lower concentrations, RSDr and RSDR were about thrice as high. On the basis of the results of this investigation, at present, the validated method is adopted as the official method for the determination of FAA patterns in the quality control of Grana Padano PDO cheese
News recommendation with CF-IDF+
Traditionally, content-based recommendation is performed using term occurrences, which are leveraged in the TF-IDF method. This method is the defacto s
Semantics-based information extraction for detecting economic events
As today's financial markets are sensitive to breaking news on economic events, accurate and timely automatic identification of events in news items is crucial. Unstructured news items originating from many heterogeneous sources have to be mined in order to extract knowledge useful for guiding decision making processes. Hence, we propose the Semantics-Based Pipeline for Economic Event Detection (SPEED), focusing on extracting financial events from news articles and annotating these with meta-data at a speed that enables real-time use. In our implementation, we use some components of an existing framework as well as new components, e.g., a high-performance Ontology Gazetteer, a Word Group Look-Up component, a Word Sense Disambiguator, and components for detecting economic events. Through their interaction with a domain-specific ontology, our novel, semantically enabled components constitute a feedback loop which fosters future reuse of acquired knowledge in the event detection process
Grated Grana Padano cheese : new hints on how to control quality and recognize imitations
The sensorial and physico-chemical characteristics described in the product specification for most PDO cheeses are inadequate to verify the compliance of cheeses on the market with the registered designation, particularly for grated products. During the past few years, much research has indicated the analytical parameters suitable for distinguishing Grana Padano (GP) from other similar hard cheeses. The characterization of grated GP is currently based on 3 analytical parameters, related to different aspects of cheese processing, which are: (i) the measurement of alkaline phosphatase (ALP) activity, a marker for possible heat treatment applied to milk, in the outermost layer of the cheese, just below the rind; (ii) the identification of specific peptides, that are identified only in the rind, due to the very slow progress of proteolysis in the rind during GP cheese ripening; and (iii) the free amino acid (FAA) composition. In the present study, we developed an extraction method, based on density gradient centrifugation of solubilized cheese, to separate the outermost layer of the cheeses from the rest in grated cheese, and we proposed a simplified criterion to evaluate the "typicalness" of the FAA pattern. The quality control scheme based on ALP activity, detection of specific peptides and FAA pattern was applied to more than 300 samples of marketed grated GP collected over three years, 10% of which were collected outside Italy, and 3c 100 samples of grated generic ("Grana-type") hard cheeses. The results demonstrate that the simultaneous application of the three parameters allows one to distinguish grated GP from similar, non-PDO grated hard cheeses, and to recognize irregular GP cheeses
Macromolecular Traits in the African Rice Oryza glaberrima and in Glaberrima/Sativa Crosses, and Their Relevance to Processing
Molecular properties of proteins and starch were investigated in 2 accessions of Oryza glaberrima and Oryza sativa, and in one NERICA cross between the 2 species, to assess traits that could be relevant to transformation into specific foods. Protein nature and organization in O. glaberrima were different from those in O. sativa and in NERICA. Despite the similar cysteine content in all samples, thiol accessibility in O. glaberrima proteins was higher than in NERICA or in O. sativa. Inter-protein disulphide bonds were important for the formation of protein aggregates in O. glaberrima, whereas non-covalent protein-protein interactions were relevant in NERICA and O. sativa. DSC and NMR studies indicated only minor differences in the structure of starch in these species, as also made evident by their microstructural features. Nevertheless, starch gelatinization in O. glaberrima was very different from what was observed in O. sativa and NERICA. The content of soluble species in gelatinized starch from the various species in the presence/absence of treatments with specific enzymes indicated that release of small starch breakdown products was lowest in O. glaberrima, in particular from the amylopectin component. These findings may explain the low glycemic index of O. glaberrima, and provide a rationale for extending the use of O. glaberrima in the production of specific rice-based products, thus improving the economic value and the market appeal of African crops
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