A method that combines category-based and keyword-based concepts for a better information retrieval system is introduced. To improve document clustering, a document similarity measure based on cosine vector and keywor...A method that combines category-based and keyword-based concepts for a better information retrieval system is introduced. To improve document clustering, a document similarity measure based on cosine vector and keywords frequency in documents is proposed, but also with an input ontology. The ontology is domain specific and includes a list of keywords organized by degree of importance to the categories of the ontology, and by means of semantic knowledge, the ontology can improve the effects of document similarity measure and feedback of information retrieval systems. Two approaches to evaluating the performance of this similarity measure and the comparison with standard cosine vector similarity measure are also described.展开更多
Support vector machines have met with significant success in the information retrieval field, especially in handling text classification tasks. Although various performance estimators for SVMs have been proposed, thes...Support vector machines have met with significant success in the information retrieval field, especially in handling text classification tasks. Although various performance estimators for SVMs have been proposed, these only focus on accuracy which is based on the leave-one-out cross validation procedure. Information-retrieval-related performance measures are always neglected in a kernel learning methodology. In this paper, we have proposed a set of information-retrieval-oriented performance estimators for SVMs, which are based on the span bound of the leave-one-out procedure. Experiments have proven that our proposed estimators are both effective and stable.展开更多
Sensorial information is very difficult to elicit, to represent and to manage because of its complexity. Fuzzy logic provides an interesting means to deal with such information, since it allows us to represent impreci...Sensorial information is very difficult to elicit, to represent and to manage because of its complexity. Fuzzy logic provides an interesting means to deal with such information, since it allows us to represent imprecise, vague or incomplete descriptions, which are very common in the management of subjective information. Aggregation methods proposed by fuzzy logic are further useful to combine the characteristics of the various components of sensorial information.展开更多
The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession...The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession of rangelands, has been subject to disorders for the variety of reasons since many years ago. Floods, hungry animals and desertification are the consequences of such disorders. Therefore, the rangeland managers have suggested the multiple usages of rangelands based on their existing talent and efficiency which is called ＂rangeland suitability＂. In this research, based on bio-diversity potentials of the region, the recognition and functions of plants of Alborz Mountain rangelands have been considered as rangeland management tools. The sampling has been carried out in work units （combination of traditional systems in plant types） randomly-systematically by setting ten 50 m transects and putting down a metal bar. In this way, the relative frequency of medicinal and nectarous rangeland plants in work units has been evaluated. Planning for multiple usage of rangelands were performed based on two criteria of suitability of medicinal and nectarous plants, 1991 Food and Agriculture Organization （FAO） method, and using Geographical Information Systems （GIS） with the scale of 1：50,000. The best-growing habitat of the plants was selected based on the modeling. By proving the existence of environmental gradient, one can recommend the above methods to study the environmental factors as complementary to incarnation models theories.展开更多
基金The Young Teachers Scientific Research Foundation (YTSRF) of Nanjing University of Science and Technology in the Year of2005-2006.
文摘A method that combines category-based and keyword-based concepts for a better information retrieval system is introduced. To improve document clustering, a document similarity measure based on cosine vector and keywords frequency in documents is proposed, but also with an input ontology. The ontology is domain specific and includes a list of keywords organized by degree of importance to the categories of the ontology, and by means of semantic knowledge, the ontology can improve the effects of document similarity measure and feedback of information retrieval systems. Two approaches to evaluating the performance of this similarity measure and the comparison with standard cosine vector similarity measure are also described.
文摘Support vector machines have met with significant success in the information retrieval field, especially in handling text classification tasks. Although various performance estimators for SVMs have been proposed, these only focus on accuracy which is based on the leave-one-out cross validation procedure. Information-retrieval-related performance measures are always neglected in a kernel learning methodology. In this paper, we have proposed a set of information-retrieval-oriented performance estimators for SVMs, which are based on the span bound of the leave-one-out procedure. Experiments have proven that our proposed estimators are both effective and stable.
文摘Sensorial information is very difficult to elicit, to represent and to manage because of its complexity. Fuzzy logic provides an interesting means to deal with such information, since it allows us to represent imprecise, vague or incomplete descriptions, which are very common in the management of subjective information. Aggregation methods proposed by fuzzy logic are further useful to combine the characteristics of the various components of sensorial information.
文摘The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession of rangelands, has been subject to disorders for the variety of reasons since many years ago. Floods, hungry animals and desertification are the consequences of such disorders. Therefore, the rangeland managers have suggested the multiple usages of rangelands based on their existing talent and efficiency which is called ＂rangeland suitability＂. In this research, based on bio-diversity potentials of the region, the recognition and functions of plants of Alborz Mountain rangelands have been considered as rangeland management tools. The sampling has been carried out in work units （combination of traditional systems in plant types） randomly-systematically by setting ten 50 m transects and putting down a metal bar. In this way, the relative frequency of medicinal and nectarous rangeland plants in work units has been evaluated. Planning for multiple usage of rangelands were performed based on two criteria of suitability of medicinal and nectarous plants, 1991 Food and Agriculture Organization （FAO） method, and using Geographical Information Systems （GIS） with the scale of 1：50,000. The best-growing habitat of the plants was selected based on the modeling. By proving the existence of environmental gradient, one can recommend the above methods to study the environmental factors as complementary to incarnation models theories.
