ABSTRACT
This paper presents a new method for document retrieval using fuzzy-valued concept networks, where the relevant degrees between the concepts in a fuzzy-valued concept network are represented by arbitrary shapes of fuzzy numbers. There are two kinds of relevant relationships between any two concepts in a fuzzy-valued concept network, i.e., fuzzy positive association and fuzzy negative association. The relevant matrices and the relationship matrices are used to model the fuzzy-valued concept network. The elements in a relevant matrix represent the relevant degrees between concepts. The elements in a relationship matrix represent the relevant relationships between concepts. Furthermore, ne also allow users' queries to be represented by arbitrary shapes of fuzzy numbers and to use fuzzy positive association relationship and fuzzy negative association relationship for formulating their queries for increasing the flexibility of fuzzy information retrieval systems. We also present an information retrieval method in the Internet environment based on the network-type fuzzy-valued concept network architecture.
ABSTRACT
In this paper, we present a new method for fuzzy query processing for document retrieval based on extended fuzzy concept networks. In an extended fuzzy concept network, there are four kinds of fuzzy relationships between concepts, i.e., fuzzy positive association, fuzzy negative association, fuzzy generalization, and fuzzy specialization. An extended fuzzy concept network can be modeled by a relation matrix and a relevance matrix, where the elements in a relation matrix represent the fuzzy relationships between concepts, and the elements in a relevance matrix indicate the degrees of relevance between concepts. The implicit fuzzy relationships between concepts can be inferred by the transitive closure of the relation matrix. The implicit degrees of relevance between concepts also can be inferred by the transitive closure of the relevance matrix. The proposed method allows the users to perform positive queries, negative queries, generalization queries, and specialization queries. The proposed method allows the users to perform fuzzy queries in a more flexible and more intelligent manner.
ABSTRACT
In this paper, we extend the works of Chen and Horng (1996) and Itzkovich and Hawkes (1994) to present a new method for finding the inheritance hierarchies in fuzzy-valued concept-networks, where the relevant values (degrees of generalization or degrees of similarity) between concepts in a fuzzy-valued concept network are represented by fuzzy numbers. The proposed method is more flexible than the ones presented previously due to the fact that it allows the grades of similarity and the grades of generalization between concepts to be represented by fuzzy numbers rather than crisp real values between zero and one or interval values in [0,1].
ABSTRACT
In this paper, we present temporal knowledge representation and reasoning techniques using time Petri nets. A method is also proposed to check the consistency of the temporal knowledge. The proposed method can overcome the drawback of the one presented in Yao (1994). It provides a useful way to check the consistency of the temporal knowledge.
ABSTRACT
Blood loss in patients on cardiopulmonary bypass is tremendously large after surgery due to platelet dysfunction. Desmopressin acetate (a synthetic analogue of vasopressin) has been shown to improve blood coagulation in a variety of platelet disorders especially in patients with hemophilia, von Willebrand's disease and uremia. Recent years, it has been used to treat patients with severe platelet dysfunction and profuse hemorrhage after cardiopulmonary bypass. We have investigated the effect of desmopressin acetate administration in randomized trials of 48 adult patients placed on cardiopulmonary bypass during cardiac surgery. Twenty four patients received intravenous infusion 0.3 microgram/kg desmopressin acetate one hour after cardiopulmonary bypass and other patients only received a placebo. Comparing with the control group, patients receiving desmopressin had shortened bleeding time (3.4 +/- 0.6 vs 5.1 +/- 1.6 mins, 8 hrs post bypass), lessened blood loss (482 +/- 258 ml vs 1430 +/- 733 ml, 24 hrs post bypass) and received fewer blood component therapy (pack RBC 2.7 +/- 2.2 vs 6.6 +/- 3.2 units, FFP 4.3 +/- 2.4 vs 11.7 +/- 5.7 units, platelet 3.8 +/- 5.0 vs 8.4 +/- 7.2 units). We conclude that desmopressin acetate can improve blood coagulation ability with safety and in reducing blood loss in patients after cardiopulmonary bypass.
