检索结果-内蒙古大学图书馆

ℋ ∞ state feedback switched control for discrete time-varying polytopic systems

International Journal of Control 2013年第4期86卷 591-598页

作者： Deaecto, Grace S. grace.deaecto@unifesp.br Geromel, José C. ICT / Institute of Science and Technology UNIFESP 12231-280 São José dos Campos SP Brazil DSCE / School of Electrical and Computer Engineering UNICAMP 13083 - 852 Campinas SP Brazil

This article treats, in a new framework, a classical design problem, namely ℋ∞state feedback switched control for discrete time-varying polytopic systems. The main goal is to jointly design a set of state feedback gains and a switching rule in order to assure a pre-specified ℋ∞guaranteed level. The main contribution is to generalise switched system results to design a switched controller that does not require online measurements of the time-varying parameters. This property has important consequences mainly because the performance quality is preserved even in the lack of parameter information. Our conditions are based on modified Riccati–Metzler inequalities and are described in terms of linear matrix inequalities. An academical example compares the proposed technique with others from the literature. [ABSTRACT FROM AUTHOR]

关键词： discrete-time switched systems LPV discrete-time systems control polytopic systems state feedback switched control

来源：评论

学校读者我要写书评

暂无评论

Towards the applicability of alf to model Cyber-Physical Systems

Towards the applicability of alf to model Cyber-Physical Sys...

引用

Federated Conference on computer science and Information Systems (FedCSIS)

作者： Alessandro Gerlinger Romero Klaus Schneider Maurício Gonçalves Vieira Ferreira Brazilian National Institute for Space Research São José dos Campos São Paulo Brazil Computer Science Department University of Kaiserslautern Kaiserslautern Germany

Systems engineers use SysML as a vendor-independent language to model Cyber-Physical Systems. However, SysML does not provide an executable form to define behavior but this is needed to detect critical issues as soon as possible. Action Language for Foundational UML (Alf) integrated with SysML can offer some degree of precision. In this paper, we present an Alf specialization that introduces the synchronous-reactive model of computation to SysML, through definition of not explicitly constrained semantics: timing, concurrency, and inter-object communication. The proposed specialization is well-suited for safety-critical systems because it is deterministic. We study one example already modeled in the literature, to compare these approaches with our one. The initial results show that the proposed specialization helps to couple complexity, provides better composition, and enables deterministic behavior definition.

关键词： Unified modeling language Semantics Computational modeling Object oriented modeling Syntactics Abstracts

来源：评论

学校读者我要写书评

暂无评论

Multi-objective evolutionary algorithm for variable selection in calibration problems: A case study for protein concentration prediction

Multi-objective evolutionary algorithm for variable selectio...

引用

2013 IEEE Congress on Evolutionary Computation, CEC 2013

作者： De Lucena, Daniel Vitor De Lima, Telma Woerle Da Silva Soares, Anderson Delbem, Alexandre C. B. Filho, Arlindo Rodrigues Galvao Coelho, Clarimar Jose Laureano, Gustavo Teodoro Institute of Informatics Federal University of Goiás Goiânia Brazil ICMC-USP University of São Paulo São Carlos Brazil Department of System and Control Technological Institute of Aeronautics São José dos Campos Brazil Computer Science Departament Pontifical University Catholic of Goiás Goiás Brazil

ISBN: (纸本)9781479904549

This paper presents a multi-objective formulation for variable selection in calibration problems. The prediction of protein concentration on wheat is obtained by a linear regression model using variables obtained by a spectrophotometer device. This device measure hundreds of correlated variables related with physicochemical properties and that can be used to estimate the protein concentration. The problem is the selection of a subset informative and uncorrelated variables that help the minimization of prediction error. In this work we propose the use of two objectives in this problem: the prediction error and the number of variables in the model, both related to linear equations system stability. We proposed a multi-objective formulation using two multi-objective algorithms: the NSGA-II and the SPEA-II. Additionally we propose a final decision maker method to choice the final subset of variables from the Pareto front. For the case study is used wheat data obtained by NIR spectrometry where the objective is the determination of a variable subgroup with information about protein concentration. The results of traditional techniques of multivariate calibration as the Successive Projections Algorithm (SPA), Partial Least Square (PLS) and mono-objective genetic algorithm are presents for comparisons. For NIR spectral analysis of protein concentration on wheat, the number of variables selected from 775 spectral variables was reduced for just 10 in the SPEA-II algorithm. The prediction error decreased from 0.2 in the classical methods to 0.09 in proposed approach, a reduction of 45%. The model using variables selected by SPEA-II had better prediction performance than classical algorithms and full-spectrum partial least-squares (PLS). © 2013 IEEE.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

Dynamic behaviour of chaotic cellular automata A comparative entropy analysis of regular lattices and small-world structures

Dynamic behaviour of chaotic cellular automata A comparative...

引用

IEEE International Conference on Systems, Man, and Cybernetics

作者： Heverton B. Macedo Gina M. B. Oliveira Carlos H. C. Ribeiro Dept. Informatics Goiás Federal Institute IFG Jatai Brazil Dept. Computer Science Federal University of Uberlandia UFU Uberlandia Brazil Dept. Computer Science Technological Institute of Aeronautics ITA S?o José dos Campos Brazil

ISBN: (纸本)9781479906505

This work investigates elementary cellular automata comparing their dynamic evolution on two topologies: the usual regular lattice and a small-world network constructed as a directed graph. The number of iterations for any initial perturbation to propagate over all cells of the automaton corresponds to how quickly an initial configuration reaches a high entropy state, and the temporal rate of propagation of the perturbation can be evaluated from a chaotic set of elementary cellular automata rules using an entropy measure. Results indicate that the average entropy can be nearly tripled in the small-world network topology, suggesting much faster applications (e.g. in Cryptography) from alterations in the topological arrangement of usual cellular automata regular lattices.

关键词： cellular automata dynamic behaviour small-world network Cellular automata entropy crystal lattices complex networks Network topology dynamical evolution Automata perturbation Regular cryptography

来源：评论

学校读者我要写书评

暂无评论

A Sampling Diagnostics Model for Neural System Training Optimization

A Sampling Diagnostics Model for Neural System Training Opti...

引用

International Conference on Information Technology: New Generations (ITNG)

作者： Denis Avila Montini Gustavo Ravanhani Matuck Adilson Marques Da Cunha Luiz Alberto Vieira Dias Alexandre Lima Possebon Ribeiro Alessandra Avila Montini Computer Science Division Brazilian Aeronautics Institute of Technology (ITA) Sao Jose dos Ceampos SP Brazil University of Sao Paulo (USP) Sao Paulo SP Brazil

ISBN: (纸本)9781467359603

This paper describes a hybrid-sampling model for bank fraud diagnosis, including those for multiple frauds in a banking system. The Multi-Layer Perceptron (MLP) network was used to analyze similarity, together with a statistical optimization model for sampling, to reduce the volume of used data in the diagnostics phase. The created MLP was utilized for banking transactions learning, in order to detect frauds. This neural network was tested with different configurations to improve diagnosis. The hybrid-sampling model was also employed to improve training results. The results have shown that the optimization strategy reduced the database volume and improved the learning process, presenting similar precisions to diagnose frauds detection, within this hybrid-sampling model.

关键词： Sociology Statistics Banking Probabilistic logic Computational modeling Optimization Data models

来源：评论

学校读者我要写书评

暂无评论

Expert user discovery in a spontaneous social network an approach using knowledge retrieval

Expert user discovery in a spontaneous social network an app...

引用

International Conference on Computational Aspects of Social Networks, CASON

作者： Gustavo Freitas Cristiano da Costa Jorge Barbosa Rodrigo Righi Adenauer Yamin Applied Computing Graduate Program-PlPCA University of Vale do Rio dos Sinos Sao Leopoldo Brazil Graduate Program in Computer Science-PPGC Federal University of Pelotas Pelotas Brazil

Nowadays, we can observe that finding answers on social networks is a hard and time-consuming task. The main contribution of this article is the creation of a model and algorithm that allows users to find answers to their questions using a spontaneous social network called Mingle. This algorithm uses the Mingle ontology-based knowledge base to find expert users. To achieve this, two important steps are taken: Mingle ontology is updated to support user-oriented expertise and a detailed model is created for the given algorithm. This model was created considering other three similar applications and algorithms. Moreover, we used a semantic web framework. In the end, an evaluation using real-life scenarios is applied to evaluate if the created algorithm meets the initial goals.

关键词： Social network services

来源：评论

学校读者我要写书评

暂无评论

A Robust Analysis of FLD and Orthogonal FLD on Handwritten Characters

A Robust Analysis of FLD and Orthogonal FLD on Handwritten C...

引用

International Conference on Communication Systems and Network Technologies

作者： V. N. Manjunath Aradhya S. K. Niranjan L. Hamsaveni Dept. of Master of Computer Applications Sri Jayachamarajendra College of Engineering DoS in Computer Science University of Mysore

ISBN: (纸本)9781467356039

Feature extraction is the identification of appropriate measures to characterize the component images distinctly. Extracting features is one of the most important steps in any recognition system. Hence, in this paper, we explore the concept of Orthogonalized Fisher Discriminant (OFD) for unconstrained handwritten Kannada character recognition. OFD exhibits higher performance than Fisher Linear Discriminant (FLD) due to the elimination of dependences among discriminant vectors. For subsequent classification purpose, we explore the concept of probabilistic neural network (PNN) architecture. Experiments show that OFD methods are more effective and efficient than standard FLD for handwritten character recognition.

关键词： Document Image Processing Handwritten Character Recognition FLD OFD PNN

来源：评论

学校读者我要写书评

暂无评论

A Meta-algorithm for Planning Optimization in a software Production Line 10th

A Meta-algorithm for Planning Optimization in a software Pro...

引用

International Conference on Information Technology: New Generations (ITNG)

作者： Denis Avila Montini Paulo Marcelo Tasinaffo Luiz Alberto Vieira Dias Alvaro Augusto Neto Adilson Marques Da Cunha Alessandra Avila Montini Computer Science Division Brazilian Aeronautics Institute of Technology (ITA) Sao Jose dos Campos SP Brazil Comput. Sci. Div. Brazilian Aeronaut. Inst. of Technol. (ITA) Sao Jose dos Campos Brazil University of Sao Paulo (USP) Sao Paulo SP Brazil

ISBN: (纸本)9781467359603

Nowadays there are various forms for performing software design, planning, and manufacturing. To each of these it is required a proper process definition to achieve metrological forecasting goal. In this investigation, the research area is Artificial Intelligence algorithms applied to projects for Production Lines design, characterized as Manufacturing Cells. In this type of approach the design project is aimed at improving the understanding and assertiveness in the planning of the operation, through an Intelligent Agent use. The Intelligent Agent was proposed as a model-driven and was aimed at identifying the code capacity installed in a specific programming language.

关键词： Planning Intelligent agents Production Calibration Optimization Metrology

来源：评论

学校读者我要写书评

暂无评论

Probabilistic Analysis of a 1-of-n Selection Algorithm Using a Moderately Pessimistic Decision Criterion

Probabilistic Analysis of a 1-of-n Selection Algorithm Using...

引用

Pacific Rim International Symposium on Dependable Computing

作者： Negin Fathollahnejad Emilia Villani Risat Pathan Raul Barbosa Johan Karlsson Department of Computer Science and Engineering Chalmers University of Technology Gothenburg Sweden Department of Mechanical Engineering Instituto Tecnologico de Aeronautica Sao Jose dos Campos Brazil Department of Informatics Engineering University of Coimbra Portugal

In this paper we are concerned with the fundamental problem of reaching agreement among a set of distributed processes in presence of an unbounded number of communication failures. We present a probabilistic analysis of a family of synchronous consensus algorithms that aim to solve the 1-of-n selection problem. In this problem, a set of n nodes are to select one common value among a set of n proposed values. There are two possible outcomes of each node's selection process: it can decide either to select a value, or to abort. Agreement implies that all nodes select the same value, or all nodes decide to abort. We know from previous research that it is impossible to guarantee agreement if there is no upper bound on the number of communication failures that can occur. Our aim is to study how the probability of disagreement varies for different decision criteria. The decision criterion consists of the logical expressions that determine whether a process will select a value or decide to abort based on its view of the system state. In this paper we propose and analyse a moderately pessimistic decision criterion. We compared this decision criterion with an optimistic and a pessimistic decision criterion, which we have investigated in our previous work. Our results show that the moderately pessimistic decision criterion for most configurations has a lower maximum probability of disagreement compared with the two other decision criteria. Furthermore, it provides a compromise between the optimistic and the pessimistic approaches since it reduces the probability of disagreement without increasing excessively the probability of agreeing to abort.

关键词： Probabilistic logic Algorithm design and analysis Vectors Model checking Protocols Analytical models Closed-form solutions

来源：评论

学校读者我要写书评

暂无评论

Using Thesaurus-Based Tag Clouds to Improve Test-Driven Code Search

Using Thesaurus-Based Tag Clouds to Improve Test-Driven Code...

引用

Brazilian Symposium on Software Components, Architectures and Reuse (SBCARS)

作者： Otavio Augusto Lazzarini Lemos Adriano Carvalho de Paula Gustavo Konishi Joel Ossher Sushil Bajracharya Cristina Lopes Science and Technology Department Federal University of Sao Paulo at S. J.dos Campos Brazil Donald Bren School of Information and Computer Sciences University of California at Irvine Black Duck Software Inc.

Test-driven code search (TDCS) is an approach to code search and reuse that uses test cases as inputs to form the search query. Together with the test cases that provide more semantics to the search task, keywords taken from class and method names are still required. Therefore, the effectiveness of the approach also relies on how good these keywords are, i.e., how frequently they are chosen by developers to name the desired functions. To help users choose adequate words in their query test cases, visual aids can be used. In this paper we propose thesaurus-based tag clouds to show developers terms that are more frequently used in the code repository to improve their search. Terms are generated by looking up words similar to the initial keywords on a thesaurus. Tag clouds are then formed based on the frequency in which these terms appear in the code base. Our approach was implemented with an English thesaurus as an extension to CodeGenie, a Java- and Eclipse-based TDCS tool. Our evaluation shows that the approach can help improve the number of returned results. We also noticed the visual aid can be especially useful for non-native speakers of the language in which the code repository is written. These users are frequently unaware of the most common terms used to name specific functionality in the code, in the given language.

关键词： Tag clouds Thesauri Cloud computing Visualization Search problems Color

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：