Search results for "Abstract data type"
showing 10 items of 1140 documents
A multi objective genetic algorithm for the facility layout problem based upon slicing structure encoding
2012
This paper proposes a new multi objective genetic algorithm (MOGA) for solving unequal area facility layout problems (UA-FLPs). The genetic algorithm suggested is based upon the slicing structure where the relative locations of the facilities on the floor are represented by a location matrix encoded in two chromosomes. A block layout is constructed by partitioning the floor into a set of rectangular blocks using guillotine cuts satisfying the areas requirements of the departments. The procedure takes into account four objective functions (material handling costs, aspect ratio, closeness and distance requests) by means of a Pareto based evolutionary approach. The main advantage of the propos…
A geometrical approach for inverting display color-characterization models
2008
— Some display color-characterization models are not easily inverted. This work proposes ways to build geometrical inverse models given any forward color-characterization model. The main contribution is to propose and analyze several methods to optimize the 3-D geometrical structure of an inverse color-characterization model directly based on the forward model. Both the amount of data and their distribution in color space is especially focused on. Several optimization criteria, related either to an evaluation data set or to the geometrical structure itself, are considered. A practical case with several display devices, combining the different methods proposed in the article, are considered …
Large‐scale set partitioning problems: Some real‐world instances hide a beneficial structure
2006
In this paper we consider large‐scale set partitioning problems. Our main purpose is to show that real‐world set partitioning problems originating from the container‐trucking industry are easier to tackle in respect to general ones. We show such different behavior through computational experiments: in particular, we have applied both a heuristic algorithm and some exact solution approaches to real‐world instances as well as to benchmark instances from Beasley OR‐library. Moreover, in order to gain an insight into the structure of the real‐world instances, we have performed and evaluated various instance perturbations. Didelės matematinės aibės dalijimo problemų sprendimas, nagrinėjant reali…
HyperShell: An expert system shell in a hypermedia environment—application in medical audiology
1990
HyperShell is an expert system shell developed in a hypermedia environment. Several artificial intelligence techniques such as frames and semantic networks are used in an original interpretation to enhance the interaction between the user and the program. The typical navigation tools of hypermedia such as clickable buttons and text search are extended to the semantic structure of HyperShell, creating a set of new tools. Examples from a medical expert system (Audex HM) developed in HyperShell are described.
Researches Regarding the Use of Fuzzy Controllers within CNC Feed Drives
2015
This paper presents some simulation based upon a dynamic model of a feed-drive within the structure of a CNC machine tool. A DC servomotor was considered as actuation device for the feed drive. For a given set of parameters for the position controller, two fuzzy types of fuzzy controllers were tested by means of simulation. The first fuzzy controller was a proportional one, with one input and one output, while the second one was a two variables one, with two inputs and one outputp.
Preventing Overlaps in Agglomerative Hierarchical Conceptual Clustering
2020
Hierarchical Clustering is an unsupervised learning task, whi-ch seeks to build a set of clusters ordered by the inclusion relation. It is usually assumed that the result is a tree-like structure with no overlapping clusters, i.e., where clusters are either disjoint or nested. In Hierarchical Conceptual Clustering (HCC), each cluster is provided with a conceptual description which belongs to a predefined set called the pattern language. Depending on the application domain, the elements in the pattern language can be of different nature: logical formulas, graphs, tests on the attributes, etc. In this paper, we tackle the issue of overlapping concepts in the agglomerative approach of HCC. We …
An In-Depth Experimental Comparison of RNTNs and CNNs for Sentence Modeling
2017
The goal of modeling sentences is to accurately represent their meaning for different tasks. A variety of deep learning architectures have been proposed to model sentences, however, little is known about their comparative performance on a common ground, across a variety of datasets, and on the same level of optimization. In this paper, we provide such a novel comparison for two popular architectures, Recursive Neural Tensor Networks (RNTNs) and Convolutional Neural Networks (CNNs). Although RNTNs have been shown to work well in many cases, they require intensive manual labeling due to the vanishing gradient problem. To enable an extensive comparison of the two architectures, this paper empl…
HD-RTI: an adaptive multi-light imaging approach for the quality assessment of manufactured surfaces
2021
International audience; Reflectance Transformation Imaging (RTI) is a technique for estimating surface local angular reflectance from a set of stereo-photometric images captured with variable lighting directions. The digitization of this information fully fits into the industry 4.0 approach and makes it possible to characterize the visual properties of a surface. The proposed method, namely HD-RTI, is based on the coupling of RTI and HDR imaging techniques. This coupling is carried out adaptively according to the response at each angle of illumination. The proposed method is applied to five industrial samples which have high local variations of reflectivity because of their heterogeneity of…
GEPOL: An improved description of molecular surfaces. III. A new algorithm for the computation of a solvent-excluding surface
1994
To understand and calculate the interactions of a solute with a solvent, a good method of computing the molecular surface is needed. Three kinds of surfaces may be used: the van der Waals Surface, the Accessible Surface, and the Molecular Surface. The latter is redefined in this article as the Solvent-Excluding Surface. The new algorithm for computing the Solvent-Excluding Surface included in the GEPOL93 program is described. GEPOL93 follows the same concept as former versions of GEPOL but with a full new algorithm. Thus, it computes the Solvent-Excluding Surface by filling the spaces not accessible to the solvent with a set of new spheres. The computation is controlled by three parameters:…
Space partitioning of exchange-correlation functionals with the projector augmented-wave method
2018
We implement a Becke fuzzy cells type space partitioning scheme for the purposes of exchange-correlation within the GPAW projector augmented-wave method based density functional theory code. Space partitioning is needed in the situation where one needs to treat different parts of a combined system with different exchange-correlation functionals. For example, bulk and surface regions of a system could be treated with functionals that are specifically designed to capture the distinct physics of those regions. Here, we use the space partitioning scheme to implement the quasi-nonuniform exchange-correlation scheme, which is a useful practical approach for calculating metallic alloys on the gene…