Relaxed constraints support vector machines for noisy data

Real-world data collected for computer-based applications are frequently impure. Differentiation of outliers and noisy data from normal ones is a major task in data mining applications. On the other hand, elimination of noisy and outlier data from training samples of a dataset may lead to over-fitting or information loss. A fuzzy support vector machine (FSVM) provides an effective means to deal with this problem. It reduces the effect of the noisy data and outliers by using a fuzzy membership functions. In this paper, a new formation for SVMs is introduced that considers importance degrees for training samples. The constraints of the SVM are converted to fuzzy inequalities. The proposed method, RSVM, shows better efficiency in the classification of data in different domains. Especially, using the proposed RSVM for multi-class classification of arrhythmia disease is presented at the end of this paper as a practical case study to show the effectiveness of the proposed system.     

CDA: a novel multicore scheduling for cost-aware deadline-constrained scientific workflows on the IaaS cloud

The Journal of Supercomputing - The variety of pricing models offered by cloud service providers and the availability of a wide diversity of computing resources has increased the popularity of this...     

An energy-aware distributed clustering protocol in wireless sensor networks using fuzzy logic

Clustering is an effective approach for organizing a network into a connected hierarchy, load balancing, and prolonging the network lifetime. On the other hand, fuzzy logic is capable of wisely blending different parameters. This paper proposes an energy-aware distributed dynamic clustering protocol (ECPF) which applies three techniques: (1) non-probabilistic cluster head (CH) elections, (2) fuzzy logic, and (3) on demand clustering. The remaining energy of the nodes is the primary parameter for electing tentative CHs via a non-probabilistic fashion. A non-probabilistic CH election is implemented by introducing a delay inversely proportional to the residual energy of each node. Therefore, tentative CHs are selected based on their remaining energy. In addition, fuzzy logic is employed to evaluate the fitness (cost) of a node in order to choose a final CH from the set of neighboring tentative CHs. On the other hand, every regular (non CH) node elects to connect to the CH with the least fuzzy cost in its neighborhood. Besides, in ECPF, CH elections are performed sporadically (in contrast to performing it every round). Simulation results demonstrate that our approach performs better than well known protocols (LEACH, HEED, and CHEF) in terms of extending network lifetime and saving energy.     

Online energy-efficient fair scheduling for heterogeneous multi-cores considering shared resource contention

The Journal of Supercomputing - Heterogeneous multi-core processors (HMP) are dual-objective hardware platforms which integrate both high-performance and low power consumption processors....     

Curve fitting space for classification

In this paper, a curve fitting space (CFS) is presented to map non-linearly separable data to linearly separable ones. A linear or quadratic transformation maps data into a new space for better classification, if the transformation method is properly guessed. This new CFS space can be of high or low dimensionality, and the number of dimensions is generally low, and it is equal to the number of classes. The CFS method is based on fitting a hyperplane or curve to the learning data or enclosing them into a hypersurface. In the proposed method, the hyperplanes, curves, or cortex become the axis of the new space. In the new space, a linear support vector machine multi-class classifier is applied to classify the learn data.     

A simple token-based algorithm for the mutual exclusion problem in distributed systems

Solving the problem of mutually exclusive access to a critical resource is a major challenge in distributed systems. In some solutions, there is a unique token in the whole system which acts as a privilege to access a critical resource. Practical and easily implemented, the token-ring algorithm is one of the most popular token-based mutual exclusion algorithms known in this field’s literature. However, it suffers from low scalability and a high average waiting time for resource seekers. The present paper proposes a new algorithm which employs a two-dimensional torus logical structure of N processes and the token-ring algorithm concept. It performs in a way that increasingly raises scalability and reduces the average waiting time of the token-ring algorithm. The token makes a circular movement along the columns of the two-dimensional torus (vertical ring), while the requests for the critical resource make a circular movement along the rows of the torus (horizontal ring). In this algorithm, the number of messages exchanged is between \(2\sqrt{{N}}+1\) and 3\(\sqrt{{N}}+1\) under light load situations and, under heavy load situations, is at the most three messages per critical section invocation. Thus, in contrast with the leading algorithms, the proposed algorithm has gained significant improvements, in addition to having been proved to operate correctly.     

Distributed unequal clustering algorithm in large-scale wireless sensor networks using fuzzy logic

Clustering is a promising and popular approach to organize sensor nodes into a hierarchical structure, reduce transmitting data to the base station by aggregation methods, and prolong the network lifetime. However, a heavy traffic load may cause the sudden death of nodes due to energy resource depletion in some network regions, i.e., hot spots that lead to network service disruption. This problem is very critical, especially for data-gathering scenarios in which Cluster Heads (CHs) are responsible for collecting and forwarding sensed data to the base station. To avoid hot spot problem, the network workload must be uniformly distributed among nodes. This is achieved by rotating the CH role among all network nodes and tuning cluster size according to CH conditions. In this paper, a clustering algorithm is proposed that selects nodes with the highest remaining energy in each region as candidate CHs, among which the best nodes shall be picked as the final CHs. In addition, to mitigate the hot spot problem, this clustering algorithm employs fuzzy logic to adjust the cluster radius of CH nodes; this is based on some local information, including distance to the base station and local density. Simulation results demonstrate that, by mitigating the hot spot problem, the proposed approach achieves an improvement in terms of both network lifetime and energy conservation.     

Fuzzy c-means improvement using relaxed constraints support vector machines

Fuzzy clustering is a widely applied method for extracting the underlying models within data. It has been applied successfully in many real-world applications. Fuzzy c-means is one of the most popular fuzzy clustering methods because it produces reasonable results and its implementation is straightforward. One problem with all fuzzy clustering algorithms such as fuzzy c-means is that some data points which are assigned to some clusters have low membership values. It is possible that many samples may be assigned to a cluster with low-confidence. In this paper, an efficient and noise-aware implementation of support vector machines, namely relaxed constraints support vector machines, is used to solve the mentioned problem and improve the performance of fuzzy c-means algorithm. First, fuzzy c-means partitions data into appropriate clusters. Then, the samples with high membership values in each cluster are selected for training a multi-class relaxed constraints support vector machine classifier. Finally, the class labels of the remaining data points are predicted by the latter classifier. The performance of the proposed clustering method is evaluated by quantitative measures such as cluster entropy and Minkowski scores. Experimental results on real-life data sets show the superiority of the proposed method.     

Relaxed constraints support vector machine

This paper presents a new model of support vector machines (SVMs) that handle data with tolerance and uncertainty. The constraints of the SVM are converted to fuzzy inequality. Giving more relaxation to the constraints allows us to consider an importance degree for each training samples in the constraints of the SVM. The new method is called relaxed constraints support vector machines (RSVMs). Also, the fuzzy SVM model is improved with more relaxed constraints. The new model is called fuzzy RSVM. With this method, we are able to consider importance degree for training samples both in the cost function and constraints of the SVM, simultaneously. In addition, we extend our method to solve one‐class classification problems. The effectiveness of the proposed method is demonstrated on artificial and real‐life data sets.