the ultimate goal of power system operation and planning is to increase power system reliability which enforces interconnected operation of power system. as a result of power system interconnection, the inter-area oscillation under different disturbances may cause power system partial or total blackout. dc-segmentation of interconnected power systems is a solution in which the topology of the n...

Faults in computer networks may result in millions of dollars in cost. Faults in a network need to be localized and repaired to keep the health of the network. Fault management systems are used to keep today’s complex networks running without significant cost, either by using active techniques or passive techniques. In this paper, we propose a novel approach based on imperialist competitive alg...

Most developed countries exhibit high rates of R&D performed in industry, but the situation is considerable different in medium income countries such as Portugal. Despite the lower levels of R&D, Portuguese firms have increased their competitiveness, and the country has been able to show remarkable levels of economic performance. This paper provides a framework to analyze the way in which R&D i...

Mining local structure is important in data analysis. Gaussian mixture is able to describe local structure through the covariance matrices, but when used on highdimensional data, fitly specifying such a large number of d(d + 1)=2 free elements in each covariance matrix is difficult. In this paper, by constraining the covariance matrix in decomposed orthonormal form, we propose a Local PCA algor...

This paper introduces a new learning algorithm for on-line ellipsoidal clustering. The algorithm is based on the competitive clustering scheme extended by two specific features. Elliptical clustering is accomplished by efficiently incorporating the Mahalanobis distance measure into the learning rules, and underutilization of smaller clusters is avoided by incorporating a frequency-sensitive ter...

Article history: Received 5 April 2015 Received in revised form 30 May 2015 Accepted 2 June 2015 Available online 9 June 2015 Communicated by D.-Z. Du

We prove a lower bound ρ ≥ 9.001 for the competitive ratio of the so-called online matching problem on a line. As a consequence, the online matching problem is revealed to be strictly more difficult than the “cow problem”.

Most people approach the issue of competitiveness by attempting to define what it is or what it should be. However, it is also interesting to approach the matter from a different angle by examining what factors are not essential in establishing a country’s competitiveness on world markets. While certain factors are certainly helpful for promoting competitiveness, they nonetheless should not be ...