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991.
A K-nearest neighbours method based on imprecise probabilities 总被引:1,自引:1,他引:0
Sebastien Destercke 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(5):833-844
K-nearest neighbours algorithms are among the most popular existing classification methods, due to their simplicity and good
performances. Over the years, several extensions of the initial method have been proposed. In this paper, we propose a K-nearest
neighbours approach that uses the theory of imprecise probabilities, and more specifically lower previsions. We show that
the proposed approach has several assets: it can handle uncertain data in a very generic way, and decision rules developed
within this theory allow us to deal with conflicting information between neighbours or with the absence of close neighbour
to the instance to classify. We show that results of the basic k-NN and weighted k-NN methods can be retrieved by the proposed approach. We end with some experiments on the classical data sets. 相似文献
992.
Julián Luengo José A. Sáez Francisco Herrera 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(5):863-881
Fuzzy rule-based classification systems (FRBCSs) are known due to their ability to treat with low quality data and obtain
good results in these scenarios. However, their application in problems with missing data are uncommon while in real-life
data, information is frequently incomplete in data mining, caused by the presence of missing values in attributes. Several
schemes have been studied to overcome the drawbacks produced by missing values in data mining tasks; one of the most well
known is based on preprocessing, formerly known as imputation. In this work, we focus on FRBCSs considering 14 different approaches
to missing attribute values treatment that are presented and analyzed. The analysis involves three different methods, in which
we distinguish between Mamdani and TSK models. From the obtained results, the convenience of using imputation methods for
FRBCSs with missing values is stated. The analysis suggests that each type behaves differently while the use of determined
missing values imputation methods could improve the accuracy obtained for these methods. Thus, the use of particular imputation
methods conditioned to the type of FRBCSs is required. 相似文献
993.
Yiqiao Cai Jiahai Wang Jian Yin 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(2):303-330
Differential evolution (DE) is a simple and powerful population-based search algorithm, successfully used in various scientific
and engineering fields. However, DE is not free from the problems of stagnation and premature convergence. Hence, designing
more effective search strategies to enhance the performance of DE is one of the most salient and active topics. This paper
proposes a new method, called learning-enhanced DE (LeDE) that promotes individuals to exchange information systematically.
Distinct from the existing DE variants, LeDE adopts a novel learning strategy, namely clustering-based learning strategy (CLS).
In CLS, there are two levels of learning strategies, intra-cluster learning strategy and inter-cluster learning strategy.
They are adopted for exchanging information within the same cluster and between different clusters, respectively. Experimental
studies over 23 benchmark functions show that LeDE significantly outperforms the conventional DE. Compared with other clustering-based
DE algorithms, LeDE can obtain better solutions. In addition, LeDE is also shown to be significantly better than or at least
comparable to several state-of-art DE variants as well as some other evolutionary algorithms. 相似文献
994.
Ramon Jansana Umberto Rivieccio 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(3):493-504
We introduce a new product bilattice construction that generalizes the well-known one for interlaced bilattices and others
that were developed more recently, allowing to obtain a bilattice with two residuated pairs as a certain kind of power of
an arbitrary residuated lattice. We prove that the class of bilattices thus obtained is a variety, give a finite axiomatization
for it and characterize the congruences of its members in terms of those of their lattice factors. Finally, we show how to
employ our product construction to define first-order definable classes of bilattices corresponding to any first-order definable
subclass of residuated lattices. 相似文献
995.
Zhibin Wu Jiuping Xu 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(4):577-589
In group decision making (GDM) using linguistic preference relations to obtain the maximum degree of agreement, it is desirable
to develop a consensus process prior to the selection process. This paper proposes two consensus models with linguistic information
to support the GDM consensus reaching process. Two different distance functions between linguistic preference relations are
introduced to measure both individual consistency and group consensus. Based on these measures, the consensus reaching models
are developed. The two models presented have the same concept that the expert whose preference is farthest from the group
preference needs to update their opinion according to the group preference relation. In addition, the convergence of the models
is proved. After achieving the predefined consensus level, each expert’s consistency indexes are still acceptable under the
condition that the initial preference relations are of satisfactory consistency. Finally, an example is given to show the
effectiveness of the models and to verify the theoretical results. 相似文献
996.
This paper is concerned with the neutral‐delay‐dependent and discrete‐delay‐dependent stability for uncertain neutral systems with mixed delays and norm‐bounded uncertainties. Through constructing a new augmented Lyapunov‐Krasovskii functional and proving its positive definiteness, introducing some slack matrices and using integral inequality, the improved delay‐dependent stability criteria are derived in terms of linear matrix inequalities. Numerical examples are given to illustrate the significant improvement on the conservatism of the delay bound over some existing results. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
997.
We discuss how the standard Cost-Benefit Analysis should be modified in order to take risk (and uncertainty) into account. We propose different approaches used in finance (Value at Risk, Conditional Value at Risk, Downside Risk Measures, and Efficiency Ratio) as useful tools to model the impact of risk in project evaluation. After introducing the concepts, we show how they could be used in CBA and provide some simple examples to illustrate how such concepts can be applied to evaluate the desirability of a new project infrastructure. 相似文献
998.
W. P. Bastos W. B. Cardoso A. T. Avelar N. G. de Almeida B. Baseia 《Quantum Information Processing》2012,11(6):1867-1881
This paper presents feasible experimental schemes to realize controlled teleportation protocols via photonic Faraday rotations in low-Q cavities. The schemes deal with controlled teleportation of superposition states and two-particle entanglement of atomic states. The information is encoded in lambda configured three-level atoms trapped inside coupled cavities by optical fibers. Also, we estimate the success probability and the current feasibility of the schemes. 相似文献
999.
Yong Song Yi-bin Li Cai-hong Li Gui-fang Zhang 《International Journal of Control, Automation and Systems》2012,10(1):166-172
This article demonstrates that Q-learning can be accelerated by appropriately specifying initial Q-values using dynamic wave
expansion neural network. In our method, the neural network has the same topography as robot work space. Each neuron corresponds
to a certain discrete state. Every neuron of the network will reach an equilibrium state according to the initial environment
information. The activity of the special neuron denotes the maximum cumulative reward by following the optimal policy from
the corresponding state when the network is stable. Then the initial Q-values are defined as the immediate reward plus the
maximum cumulative reward by following the optimal policy beginning at the succeeding state. In this way, we create a mapping
between the known environment information and the initial values of Q-table based on neural network. The prior knowledge can
be incorporated into the learning system, and give robots a better learning foundation. Results of experiments in a grid world
problem show that neural network-based Q-learning enables a robot to acquire an optimal policy with better learning performance
compared to conventional Q-learning and potential field-based Qlearning. 相似文献
1000.
Alejandro F. Villaverde Cesáreo Raimúndez Antonio Barreiro 《International Journal of Control, Automation and Systems》2012,10(1):78-87
Crane operation is a challenging task, due to the combined problem of obstacle avoidance and load swing suppression in underactuated
conditions. This paper presents a human-machine interface that increases the operator’s perception of a gantry crane’s workspace.
With this aim, a virtual environment resembling the workspace is connected with a haptic device. This allows the user to receive
not only visual but also tactile feedback, thus increasing maneuvering safety. Additionally, this capability is integrated
in a teleoperation setup, adopting a passivity-based control approach that guarantees overall stability. This includes also
the design of controllers by means of the IDA-PBC method. Experimental results carried out with a laboratory crane show its
feasibility for internet-based teleoperation and demonstrate the improvements on the system performance. 相似文献