22672181
Inclusion Test Algorithms for One-Unambiguous Regular Expressions
One-unambiguous regular expressions are used in DTD. It is known that inclusion for one-unambiguous regular expressions is in PTIME. However, there has been no study on algorithms for the inclusion. In this paper we present algorithms for checking inclusion of one-unambiguous regular expressions. A classical way is based on automata, following which one algorithm is provided and improvements are given. The other algorithm is based on derivatives, utilizing a property introduced here that the number of derivatives of a one-unambiguous regular expression is finite. We conducted preliminary experiments by implementing typechecking of XML using the algorithms. The results show that typechecking using the new algorithms is more efficient than the typechecking used for XDuce.
183594
Efficient Type Checking for a Subclass of Regular Expression Types
Type checking is an important problem in statically typed XML processing languages. Most type systems are implemented based on tree automata for the tree structure of XML documents and schemas. It is known that the complexity of inclusion problem for tree automata is in EXPTIME. In fact, most definitions in XML Schema are actually DTDs. The inclusion problem of DTDs can be reduced to inclusion of one-unambiguous regular expressions in DTDs. We have developed a method for type checking that works for regular expression types which are DTDs. The method is based onone-unambiguous regular expressions together with using the information of labels in DTDs, which can work in top-down or bottom-up manner. Although our method supports DTDs only now, it is general and can support more general schemas by integrating with the conventional method of type checking. The experiments show that our method is more efficient in practice.
37631893
Stereo Vision Based Floor Plane Extraction and Camera Pose Estimation
In this paper, we present a unified approach for floor plane extraction and camera pose estimation. A histogram based method is performed on the reconstructed 3-D points obtained by an onboard video-rate stereo vision system to extract candidate points of the floor plane and determine the pose of vision system simultaneously. The obstacle area is easily localized given the floor plane region. In order to improve reliability and accuracy of camera pose estimation results, the Least Median of Squares (LMedS) based fitting method is applied to estimate the floor plane parameters with the extracted candidate points. The precise pose of the onboard stereo vision system is directly acquired related to the floor plane parameters. Experimental results in real indoor environments are discussed and show the good performance.
42950226
Automated Design Approach for Analog Circuit Using Genetic Algorithm
The technology of electronic design automation (EDA) has improved the efficiency of design process, however, designer is still required much special knowledge of circuit. During the past decade, using genetic algorithm (GA) to design circuit had attracted many experts and scholars. However, too much more attention was focus on a circuit's function and many other factors had been neglected which caused the circuit had little applicability. This paper proposes an automated design approach for analog circuit based on a multi-objective adaptive GA. The multi-objective fitness evaluation method, which can dynamic adjust parameter, is selected. And a parallel evolution strategy which separates evolution of circuit structure and element value is adopted but also organically combined them by weight vectors. The experimental results indicate that this approach obviously be able to improve the evolution efficiency and could generate numbers of suitable circuits.
39027040
Fabric Handle Clusters Based on Fuzzy Clustering Algorithm
Fabric handle depends on physical and mechanical properties, which are measured by the two well-know systems, i.e., Kawabata's Evaluation System for Fabrics (KES-F) by Japan and Fabric Assurance by Simple Testing (FAST) by Austria. However, the two systems are too expensive and time-costing. A new comprehensive handle evaluation system for fabrics and yarns (CHES-FY) developed based on the single-test multiple indicator measuring principle can reflect the weight, bending, friction and tension basic mechanical behavior as well as handle through only one pulling-out test. The present paper is to select characteristic indexes from the pulling-out force and distance curve acquired by the CHES-FY system, and the characteristics make a vector which expresses the handle of the fabric based on Karhunen-Loeve (K-L) transformation; the other is to make clustering on handle of measured fabrics based on K-means fuzzy clustering. The experiments of thirty fabrics and comparisons between experimental and theoretical results were conducted, which shows that K-means fuzzy clustering algorithm is effective and accurate in sorting fabric handle based on the features selected from the pulling-out force and distance curve of the CHES-FY system.
40545913
Algebraic Constructions of Quasi-cyclic LDPC Codes - Part I: For AWGN and Binary Random Erasure Channels
This paper is the first part of a sequence of two papers that present algebraic constructions of quasi-cyclic LDPC codes for AWGN, binary random and burst erasure channels. In this paper, a class of quasi-cyclic LDPC codes for both AWGN and binary random erasure channels is constructed based on finite fields and special vector representations of finite field elements.
5724720
Heterogeneous CAD Hybrid Data Exchange Based on Feature Semantics and Geometry Representation
Product data exchange (DE) is a key technology to implement collaborative design of heterogeneous CAD. Based on analyzing layered expression of product CAD model and current methods of DE, heterogeneous CAD hybrid data exchange (HDE) based on feature semantics and geometry representation is presented. The method integrates advantages of feature semantics exchange (FSE) and geometric data exchange (GDE). It features high flexibility and reliability. A case illustrates the validity of the method