scholarly journals Structural Properties of Faces of the Cone of Copositive Matrices

Mathematics ◽  
2021 ◽  
Vol 9 (21) ◽  
pp. 2698
Author(s):  
Olga Kostyukova ◽  
Tatiana Tchemisova
Keyword(s):  
Structural Properties ◽  
Geometric Structure ◽  
Incomplete Data ◽  
Facial Structure ◽  
Copositive Matrices ◽  
Copositive Cone ◽  
Explicit Representations ◽  
The Given

In this paper, we study the properties of faces and exposed faces of the cone of copositive matrices (copositive cone), paying special attention to issues related to their geometric structure. Based on the concepts of zero and minimal zero vectors, we obtain several explicit representations of faces of the copositive cone and compare them. Given a face of the cone of copositive matrices, we describe the subspace generated by that face and the minimal exposed face containing it. Summarizing the results obtained in the paper, we systematically show what information can be extracted about the given copositive face in the case of incomplete data. Several examples for illustrating the main findings of the paper and also for justifying the usefulness of the developed approach to the study of the facial structure of the copositive cone are discussed.

scholarly journals Querying Rich Ontologies by Exploiting the Structure of Data

2020 ◽  
Vol 34 (3) ◽  
pp. 395-398 ◽  
Author(s):  
Labinot Bajraktari
Keyword(s):  
Structural Properties ◽  
Incomplete Data ◽  
Data Access ◽  
Research Community ◽  
Data Sources

Abstract Ontology-based data access (OBDA) has emerged as a paradigm for accessing heterogeneous and incomplete data sources. A fundamental reasoning service in OBDA, the ontology mediated query (OMQ) answering has received much attention from the research community. However, there exists a disparity in research carried for OMQ algorithms for lightweight DLs which have found their way into practical implementations, and algorithms for expressive DLs for which the work has had mainly theoretical oriented goals. In the dissertation, a technique that leverages the structural properties of data to help alleviate the problems that typically arise when answering the queries in expressive settings is developed. In this paper, a brief summary of the technique along with the different algorithms developed for OMQ for expressive DLs is given.

BFX: DIAGNOSING CONFLICTING REQUIREMENTS IN CONSTRAINT-BASED RECOMMENDATION

2011 ◽  
Vol 20 (02) ◽  
pp. 297-312 ◽  
Author(s):  
MONIKA SCHUBERT ◽  
ALEXANDER FELFERNIG
Keyword(s):  
Performance Evaluation ◽  
Structural Properties ◽  
Detection Algorithm ◽  
Conflict Detection ◽  
Comparative Performance ◽  
Detection Algorithms ◽  
Minimal Sets ◽  
The Given

When interacting with constraint-based recommender applications, users describe their preferences with the goal of identifying the products that fit their wishes and needs. In such a scenario, users are repeatedly adapting and changing their requirements. As a consequence, situations occur where none of the products completely fulfils the given set of requirements and users need a support in terms of an indicator of minimal sets of requirements that need to be changed in order to be able to find a recommendation. The identification of such minimal sets relies heavily on the existence of (minimal) conflict sets. In this paper we introduce BFX (Boosted FastXplain), a conflict detection algorithm which exploits the basic structural properties of constraint-based recommendation problems. BFX shows a significantly better performance compared to existing conflict detection algorithms. In order to demonstrate the performance of BFX, we report the results of a comparative performance evaluation.

scholarly journals Fault Log Recovery Using an Incomplete-data-trained FDA Classifier for Failure Diagnosis of Engineered Systems

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Hyunjae Kim ◽  
Jong Moon Ha ◽  
Jungho Park ◽  
Sunuwe Kim ◽  
Keunsu Kim ◽  
...  
Keyword(s):  
Incomplete Data ◽  
Failure Diagnosis ◽  
Fault Classification ◽  
Industrial Plant ◽  
Data Sets ◽  
Fisher Discriminant Analysis ◽  
Recovery Method ◽  
Fisher Discriminant ◽  
Engineered Systems ◽  
The Given

In the 2015 PHM Data Challenge Competition, the goal of the competition problem was to diagnose failure of industrial plant systems using incomplete data. The available data consisted of sensor measurements, control reference signals, and fault logs. A detailed description of the plant system of interest was not revealed, and partial fault logs were eliminated from the dataset. This paper presents a fault log recovery method using a machine-learning-based fault classification approach for failure diagnosis. For optimal performance, it was critical to be able to utilize a set of incomplete data and to select relevant features. First, physical interpretation of the given data was performed to select proper features for a fault classifier. Second, Fisher discriminant analysis (FDA) was employed to minimize the effect of outliers in the incomplete data sets. Finally, the type of the missing fault logs and the duration of the corresponding faults were recovered. The proposed approach, based on the use of an incomplete-data-trained FDA classifier, led to the second-highest score in the 2015 PHM Data Challenge Competition.

Effects of finishing on the air permeability of woven fabrics

2013 ◽  
Vol 10 (6) ◽  
pp. 507-514 ◽  
Author(s):  
M. Havlová
Keyword(s):  
Mechanical Properties ◽  
Geometric Structure ◽  
Physical And Mechanical Properties ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Laboratory Measurement ◽  
Textile Materials ◽  
Small Change ◽  
The Given ◽  
Non Destructive

The main aim of this paper is to estimate the influence of finishing to the permeability of woven fabrics made of multifilament threads. The property of the textile permeability is closely connected with the geometric structure of the given textile materials. A very small change in the structure of the fabric at a given location causes a change in the permeability at this location. Such a change in the structure may be due to the finishing of fabric. A demanded requirement in several applications areas of textiles is the homogeneity of their physical and mechanical properties. The laboratory measurement of the fabric permeability is very suitable for assessment of uniformity across the fabric area, because the test is very simple and non-destructive. In this research a set of polyamide and polyester multifilament woven fabrics was used. These fabrics were available both in the gray state and with the various types of applied finishes.

scholarly journals Mechanical Properties of Polypropylene: Additive Manufacturing by Multi Jet Fusion Technology

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2165
Author(s):  
Jiří Šafka ◽  
Michal Ackermann ◽  
Filip Véle ◽  
Jakub Macháček ◽  
Petr Henyš
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Structural Analysis ◽  
Structural Properties ◽  
Mechanical Response ◽  
Charpy Impact ◽  
Mechanical Tests ◽  
Fusion Technology ◽  
Hewlett Packard ◽  
The Given

Multi jet fusion (MJF) technology has proven its significance in recent years as this technology has continually increased its market share. Recently, polypropylene (PP) was introduced by Hewlett-Packard for the given technology. To our knowledge, little is known about the mechanical properties of polypropylene processed by MJF technology. During this study, standardised specimens were printed under all of the major orientations of the machine’s build space. Each of these orientations were represented by five samples. The specimens then underwent tensile, bending and Charpy impact tests to analyse their mechanical properties. The structural analysis was conducted to determine whether PP powder may be reused within the MJF process. The mechanical tests showed that the orientation of the samples significantly influences their mechanical response and must be carefully chosen to obtain the optimal mechanical properties of PP samples. We further showed that PP powder may be reused as the MJF process does not significantly alter its thermal and structural properties.

PRESERVATION OF STRUCTURAL PROPERTIES IN INTUITIONISTIC EXTENSIONS OF AN INFERENCE RELATION

2018 ◽  
Vol 24 (3) ◽  
pp. 291-305 ◽  
Author(s):  
TOR SANDQVIST
Keyword(s):  
Structural Properties ◽  
Sequent Calculus ◽  
General Nature ◽  
Cut Elimination ◽  
Formal Proofs ◽  
Structural Rules ◽  
Logical Operators ◽  
First Order ◽  
Order Language ◽  
The Given

AbstractThe article approaches cut elimination from a new angle. On the basis of an arbitrary inference relation among logically atomic formulae, an inference relation on a language possessing logical operators is defined by means of inductive clauses similar to the operator-introducing rules of a cut-free intuitionistic sequent calculus. The logical terminology of the richer language is not uniquely specified, but assumed to satisfy certain conditions of a general nature, allowing for, but not requiring, the existence of infinite conjunctions and disjunctions. We investigate to what extent structural properties of the given atomic relation are preserved through the extension to the full language. While closure under the Cut rule narrowly construed is not in general thus preserved, two properties jointly amounting to closure under the ordinary structural rules, including Cut, are.Attention is then narrowed down to the special case of a standard first-order language, where a similar result is obtained also for closure under substitution of terms for individual parameters. Taken together, the three preservation results imply the familiar cut-elimination theorem for pure first-order intuitionistic sequent calculus.In the interest of conceptual economy, all deducibility relations are specified purely inductively, rather than in terms of the existence of formal proofs of any kind.

On Role of S-Synchronizability and Excitation Constancy in Structural Identifiability Problem of Nonlinear Systems

2021 ◽  
Vol 22 (2) ◽  
pp. 59-70
Author(s):  
N. N. Karabutov
Keyword(s):  
Nonlinear System ◽  
Geometric Structure ◽  
Nonlinear Dynamic System ◽  
System Structure ◽  
Structural Identifiability ◽  
Geometric Framework ◽  
System Requirements ◽  
Identifiability Problem ◽  
The Given

A class of dynamical systems with a single nonlinearity considered. The S-synchronizability concept of input introduced. It is shown that S-synchronizability is a condition for the structural identifiability of a nonlinear system. The decisionmaking on structural identifiability based on the properties analysis for a special class of geometric frameworks. Geometric frameworks reflect properties of the nonlinear dynamic system. Requirements for the model allowed us to obtain a geometric structure based on the input and output data considered. The constant excitation effect of input on the structural identifiability of the system is studied. The constant excitation effect of input studied on the structural identifiability of the system. Nonfulfillment the constant excitation condition gives a nonsignificant geometric framework. Various types of structural identifiability based on structure analysis considered. The concept of d-optimality described properties of the geometric structure introduced. Conditions for non-identifiability of nonlinear system structure obtained if the d-optimality of the geometric framework does not hold for the given properties of the input. Methods for estimating identifiability of the system and determining the identifiability area under uncertainty proposed. The proposed approach is generalized to the system having two nonlinearities. Conditions for partial structural identifiability obtained. Structural identifiability features of this class systems noted. The method for estimating the structure of the system proposed when the condition of structural identifiability satisfied. It has shown how the phase portrait used to estimate the system non-identifiability. A method proposed for constructing the structural identifiability domain of the system. Proposed methods and procedures are applied to study systems with Bouc-Wen hysteresis and two nonlinearity.

scholarly journals Analyzing Some Structural Properties of Topological B-Algebras

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Narciso C. Gonzaga
Keyword(s):  
Structural Properties ◽  
Propositional Logic ◽  
Algebraic System ◽  
Neighborhood Base ◽  
The Given ◽  
Constant Element

In this study, we investigate the topology on B-algebras: an algebraic system of propositional logic. We define here the notion of topological B-algebras (briefly, TB-algebras) and some properties are investigated. A characterization of TB-algebras based on neighborhoods is provided. We also provide a filterbase that generates a unique B-topology, making a TB-algebra in which the filterbase is a neighborhood base of the constant element, provided that the given B-algebra is commutative. Finally, we investigate subalgebras of TB-algebras and introduce the notion of quotient TB-algebras of the given B-algebra.

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