The Experts below are selected from a list of 17331 Experts worldwide ranked by ideXlab platform
Umberto Straccia - One of the best experts on this subject based on the ideXlab platform.
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Defeasible inheritance-based description logics
Journal of Artificial Intelligence Research, 2013Co-Authors: Giovanni Casini, Umberto StracciaAbstract:Defeasible inheritance networks are a non-monotonic framework that deals with hierarchical knowledge. On the other hand, rational Closure is acknowledged as a landmark of the preferential approach to non-monotonic reasoning. We will combine these two approaches and define a new non-monotonic Closure Operation for propositional knowledge bases that combines the advantages of both. Then we redefine such a procedure for Description Logics (DLs), a family of logics well-suited to model structured information. In both cases we will provide a simple reasoning method that is built on top of the classical entailment relation and, thus, is amenable of an implementation based on existing reasoners. Eventually, we evaluate our approach on well-known landmark test examples.
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defeasible inheritance based description logics
International Joint Conference on Artificial Intelligence, 2011Co-Authors: Giovanni Casini, Umberto StracciaAbstract:Defeasible inheritance networks are a nonmonotonic framework that deals with hierarchical knowledge. On the other hand, rational Closure is acknowledged as a landmark of the preferential approach. We will combine these two approaches and define a new non-monotonic Closure Operation for propositional knowledge bases that combines the advantages of both. Then we redefine such a procedure for Description Logics, a family of logics well-suited to model structured information. In both cases we will provide a simple reasoning method that is build on top of the classical entailment relation.
Giovanni Casini - One of the best experts on this subject based on the ideXlab platform.
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Defeasible inheritance-based description logics
Journal of Artificial Intelligence Research, 2013Co-Authors: Giovanni Casini, Umberto StracciaAbstract:Defeasible inheritance networks are a non-monotonic framework that deals with hierarchical knowledge. On the other hand, rational Closure is acknowledged as a landmark of the preferential approach to non-monotonic reasoning. We will combine these two approaches and define a new non-monotonic Closure Operation for propositional knowledge bases that combines the advantages of both. Then we redefine such a procedure for Description Logics (DLs), a family of logics well-suited to model structured information. In both cases we will provide a simple reasoning method that is built on top of the classical entailment relation and, thus, is amenable of an implementation based on existing reasoners. Eventually, we evaluate our approach on well-known landmark test examples.
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defeasible inheritance based description logics
International Joint Conference on Artificial Intelligence, 2011Co-Authors: Giovanni Casini, Umberto StracciaAbstract:Defeasible inheritance networks are a nonmonotonic framework that deals with hierarchical knowledge. On the other hand, rational Closure is acknowledged as a landmark of the preferential approach. We will combine these two approaches and define a new non-monotonic Closure Operation for propositional knowledge bases that combines the advantages of both. Then we redefine such a procedure for Description Logics, a family of logics well-suited to model structured information. In both cases we will provide a simple reasoning method that is build on top of the classical entailment relation.
Zhuo Zhang - One of the best experts on this subject based on the ideXlab platform.
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constructing l fuzzy concept lattices without fuzzy galois Closure Operation
Fuzzy Sets and Systems, 2018Co-Authors: Zhuo ZhangAbstract:Abstract Improving construction efficiency of fuzzy concept lattices remains one of the important issues in the field of fuzzy formal concept analysis. Building L-fuzzy concept lattice is usually based on the Closure Operation of the fuzzy Galois connection, and each Closure Operation needs to scan the fuzzy concept context twice. This becomes a significant computing overhead, especially when the fuzzy formal context is large. We propose a batch-mode algorithm for directly constructing fuzzy concept lattices based on union and intersection Operations of the fuzzy set that scans the fuzzy formal context once only. Experimental results show that it improves the construction efficiency of the complete fuzzy concept lattice, especially for large fuzzy formal contexts with small truth sets.
Siqveland Arvid - One of the best experts on this subject based on the ideXlab platform.
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The algebra of observables in noncommutative deformation theory
'Elsevier BV', 2019Co-Authors: Eriksen Eivind, Siqveland ArvidAbstract:We consider the algebra of observables and the (formally) versal morphism defined by the noncommutative deformation functor of a family of right modules over an associative k-algebra A. By the Generalized Burnside Theorem, due to Laudal, η is an isomorphism when A is finite dimensional, is the family of simple A-modules, and k is an algebraically closed field. The purpose of this paper is twofold: First, we prove a form of the Generalized Burnside Theorem that is more general, where there is no assumption on the field k. Secondly, we prove that the -construction is a Closure Operation when A is any finitely generated k-algebra and is any family of finite dimensional A-modules, in the sense that is an isomorphism when and is considered as a family of B-module
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The algebra of observables in noncommutative deformation theory
'Elsevier BV', 2019Co-Authors: Eriksen Eivind, Siqveland ArvidAbstract:We consider the algebra $\mathcal O(\mathsf M)$ of observables and the (formally) versal morphism $\eta: A \to \mathcal O(\mathsf M)$ defined by the noncommutative deformation functor $\mathsf{Def}_{\mathsf M}$ of a family $\mathsf M = \{ M_1, \dots, M_r \}$ of right modules over an associative $k$-algebra $A$. By the Generalized Burnside Theorem, due to Laudal, $\eta$ is an isomorphism when $A$ is finite dimensional, $\mathsf M$ is the family of simple $A$-modules, and $k$ is an algebraically closed field. The purpose of this paper is twofold: First, we prove a form of the Generalized Burnside Theorem that is more general, where there is no assumption on the field $k$. Secondly, we prove that the $\mathcal O$-construction is a Closure Operation when $A$ is any finitely generated $k$-algebra and $\mathsf M$ is any family of finite dimensional $A$-modules, in the sense that $\eta_B: B \to \mathcal O^B(\mathsf M)$ is an isomorphism when $B = \mathcal O(\mathsf M)$ and $\mathsf M$ is considered as a family of $B$-modules.Comment: 9 page
Weiming Zhu - One of the best experts on this subject based on the ideXlab platform.
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treatment of 21 cases of chronic radiation intestinal injury by staging ileostomy and Closure Operation
Chinese Journal of Gastrointestinal Surgery, 2018Co-Authors: Kangwen Cheng, Zhenguo Zhao, Jian Wang, Weiming ZhuAbstract:Objective To summarize the application of staged ileostomy and Closure Operation combined with nutritional support therapy in the treatment of chronic radiation intestinal injury (CRII) . Methods Clinical data of patients with definite radiation history and pathological diagnosis of CRII receiving treatment at Department of General Surgery, Jinling Hospital from January 2012 to December 2016 were retrospectively analyzed. Patients who were diagnosed with tumor recurrence during Operation or by postoperative pathology were excluded. Patients undergoing stageⅠ ileostomy and stageⅡ Closure Operation combined with nutrition support therapy were enrolled to the cohort. Detailed scheme of stage I ileostomy and therapeutic time were determined by clinical symptoms and nutritional status. While performing ileostomy, the removal of intestinal lesions depended on range and degree of intestinal injury. Nutritional support therapy and other symptom-relieving therapy were offered after surgery. Timing for stageⅡ Closure Operation was decided according to nutritional status of patients. Lesions of remaining intestine were determined during Operation, then necessary intestinal resection and Closure Operation were performed. Adhesion classification of radiation intestinal injury (total five levels) proposed by our center was adopted to evaluate the level and range of intestinal lesions. Level 0 indicated no adhesion between injured intestinal loop and surrounding organs; level 1 indicated that the adhesion and fibrosis were limited to right pelvis; level 2 indicated that the adhesion included all pelvis and the adhesion was severe and difficult to divide; level 3 was the forward extension of level 2 adhesion, which was between injured intestinal loop and anterior pelvic wall; level 4 was the upward extension of level 3 adhesion, which was between injured intestinal loop and anterior abdominal wall. Clavien-Dindo classification (lower level means milder symptom) and complication comprehensive index (CCI, lower CCI means milder symptom) calculated by on-line program (http: //www.assessurgery. com) were applied to estimate postoperative complications. Resected intestinal length, adhesion classification of radiation intestinal injury, postoperative complications and time to total enteral nutritional (TEN) of both surgeries and nutritional status (body mass index and serum albumin) were compared between stage Ⅰ ileostomy and stage Ⅱ Closure Operation. Results Twenty-one patients were enrolled in the research with 2 males and 19 females. Primary tumor included 14 cervical cancers, 3 rectal cancers, 1 endometrial cancer, 1 ovarian carcinoma, 1 seminoma and 1 mixed germ cell tumor. Median interval between the end of radiation and radiation intestinal injury was 7 (2 to 91) months and median interval between the incidence of radiation intestinal injury and ileostomy was 5 (<1 to 75) months. Operative indications for ileostomy were obstruction in 14 cases (66.7%) , intestinal internal fistula in 1 case (4.8%) , intestinal outer fistula in 2 cases (9.5%) , radiation proctitis in 3 cases (14.3%) and acute intestinal perforation in 1 case (4.8%) . Average age of patients undergoing stageⅠ ileostomy was 48 (18 to 60) years with BMI (17.0±2.7) kg/m2 and serum albumin (36.8±5.2) g/L. Patients undergoing stage Ⅱ Closure Operation had significantly higher BMI [ (18.4±2.0) kg/m2, t=-2.747, P=0.013] and higher serum albumin [ (40.8±3.6) g/L, t=-3.505, P=0.002]. Average interval between stage Ⅰ ileostomy and stage Ⅱ Closure surgery was (197±77) days. Resected intestinal length of stageⅠ ileostomy was which was significantly longer than that of stage Ⅱ Closure surgery [ (74.0±56.1) cm vs. (15.5±10.4) cm, t=4.547, P= 0.000]. Abdominal adhesion classification of stageⅡ ileostomy plus Closure Operation was significantly better as compared to stage I ileostomy (Z=-3.347, P=0.001) . Morbidity of postoperative complications in stage Ⅰ ileostomy was 52.4% (11/21) , which decreased to 19.0% (4/21) in stageⅡ Operation with significant difference (χ2=5.081, P=0.024) . Postoperative complication Clavien-Dindo classification and CCI scores in stageⅡ Operation were significantly lower than those in stageⅠ Operation (P=0.006 and P=0.002) . Till June 2017, 17 of 21 patients (81.0%) were followed-up for (28±18) months. Except for 2 cases of relapse, 15 patients recovered to normal diet. Conclusions Application of staged ileostomy and Closure Operation combined with nutritional support therapy to CRII is in accordance with the principle of injury control surgery. Furthermore, this staged approach is safe and effective, can reduce the morbidity and the severity of complications, and can also be helpful to decide the margin for intestinal resection. Key words: Chronic radiation intestinal injury; Ileostomy; Closure Operation; Nutrition support therapy