42681842
A fixture design system for networked manufacturing
Fixture design is a complex and intuitive process. An efficient fixture design system is essential to cut costs and reduce product lead time. For networked manufacturing, the fixture design system must contain characteristics of rapid configuration designing, three-dimensional (3D) modelling, a completely standardized elements database, and it should be able to transfer information with various other systems. For the requirement of rapid configuration design, based on the analysis of the contents and characteristics of fixture design, a hybrid CBR/KBR (case-based reasoning/knowledge-based reasoning) fixture design method is proposed, with CBR as its core, KBR as its assistant and CBR as the support of case-adaptation process. Using design information, the designer can obtain a satisfactory subset of possible configuration designs of a fixture from the KBR process. Then the designer, using this subset and other information (via FIXCOD system), can obtain a similar design of the fixture from the retrieving case database, and then finally use the CBR adaptation technique to obtain the satisfied design of fixture. Networked information releasing technology is applied to part design in the computer aided design (CAD) system, and a new 3D modelling method is presented, driven by networked parameters. The data on the web are integrated into the CAD system to realize multithreading data exchange between the web information releasing system and the CAD system, which will make the CAD system obtain data from the web. Then networked 3D modelling will be realized by the driving of parameters from the web, and a proved model based on CATIA is provided. The internet and the use of extensible mark-up language (XML) as a file format provide a means for the transfer of information and knowledge between the various computer aided manufacturing (CAM) systems. The system has been implemented using Java and is based on a three-tier browser/server (B/S) architecture. This ensures the platform independent performance of the system.
3937587
DC Coefficients Recovery-based Error Concealment Technique for Mpeg-2 Video Streams
118810862
Transformation theorems for fuzzy integrals on fuzzy sets
Abstract In this paper, Sugeno's fuzzy integrals studied in [5,8,9] are generalized, some equivalent definitions of fuzzy integrals on fuzzy sets are given, and several transformation theorems of such type of fuzzy integrals are proved. These results reveal the relations between the fuzzy integrals on fuzzy sets and on classical sets.
16506342
Error bounds for complementarity problems with tridiagonal nonlinear functions
In this paper we consider the complementarity problem NCP(f) with f(x) = Mx + φ(x), where M ∈ Rn×n is a real matrix and φ is a so-called tridiagonal (nonlinear) mapping. This problem occurs, for example, if certain classes of free boundary problems are discretized. We compute error bounds for approximations $${\hat x}$$ to a solution x* of the discretized problems. The error bounds are improved by an iterative method and can be made arbitrarily small. The ideas are illustrated by numerical experiments.
207241633
A Shortest Augmenting Path Algorithm for the Semi-Assignment Problem
The objective of this study is to develop a shortest augmenting path algorithm for solving the semi-assignment problem and conduct an extensive computational comparison with the best alternative approaches. The algorithm maintains dual feasibility and complementary slackness and works toward satisfying primal feasibility. Effective heuristics arc used to achieve an excellent advanced start, and convergence is assured via the use of the shortest augmenting path procedure using reduced costs for arc lengths. Unlike other algorithms, such as the primal simplex or the auction algorithm, each iteration during the final phase of the procedure also known as the end-game achieves one additional assignment. The software implementations of our algorithm are fastest for the semi-assignment problems that we tested. Our dense code is also faster than the best software for assignment problems. In addition, the algorithm has the best polynomial worst-case running time bound that we have seen; and the memory requirements are relatively small.
60798461
Implementation of frequency offset correction using CORDIC algorithm for 5 GHz WLAN applications
This paper presents an efficient implementation of frequency offset correction for the IEEE 802.1 1a wireless LAN systems. A hybrid architecture is proposed for implementing angle rotation using the radix-4 CORDIC algorithm. Targeted for 5 GHz WLAN applications and tailored to be implemented using a specific process technology, which is 0.18 /spl mu/m in our case, the proposed architecture can achieve a good compromise between hardware area and processing latency.
17770433
A generalized expansion matching based feature extractor
A novel and efficient generalized feature extraction method is presented based on the expansion matching (EXM) method and the Karhunen-Loueve (KL) transform. The EXM method is used to design optimal detectors for different features. The KL representation is used to define an optimal basis for representing these EXM feature detectors with minimum truncation error. Input images are then analyzed with the resulting KL basis set. The KL coefficients obtained from the analysis are used to efficiently reconstruct the response due to any combination of feature detectors. The method is applied to real images and successfully extracts a variety of arc and edge features as well as complex junction features formed by combining two or more arc or line features.