Search results for "oftware"
showing 10 items of 7396 documents
Why is this an anomaly? Explaining anomalies using sequential explanations
2022
Abstract In most applications, anomaly detection operates in an unsupervised mode by looking for outliers hoping that they are anomalies. Unfortunately, most anomaly detectors do not come with explanations about which features make a detected outlier point anomalous. Therefore, it requires human analysts to manually browse through each detected outlier point’s feature space to obtain the subset of features that will help them determine whether they are genuinely anomalous or not. This paper introduces sequential explanation (SE) methods that sequentially explain to the analyst which features make the detected outlier anomalous. We present two methods for computing SEs called the outlier and…
Classification Similarity Learning Using Feature-Based and Distance-Based Representations: A Comparative Study
2015
Automatically measuring the similarity between a pair of objects is a common and important task in the machine learning and pattern recognition fields. Being an object of study for decades, it has lately received an increasing interest from the scientific community. Usually, the proposed solutions have used either a feature-based or a distance-based representation to perform learning and classification tasks. This article presents the results of a comparative experimental study between these two approaches for computing similarity scores using a classification-based method. In particular, we use the Support Vector Machine as a flexible combiner both for a high dimensional feature space and …
An improved distance-based relevance feedback strategy for image retrieval
2013
Most CBIR (content based image retrieval) systems use relevance feedback as a mechanism to improve retrieval results. NN (nearest neighbor) approaches provide an efficient method to compute relevance scores, by using estimated densities of relevant and non-relevant samples in a particular feature space. In this paper, particularities of the CBIR problem are exploited to propose an improved relevance feedback algorithm based on the NN approach. The resulting method has been tested in a number of different situations and compared to the standard NN approach and other existing relevance feedback mechanisms. Experimental results evidence significant improvements in most cases.
Interactive Image Retrieval Using Smoothed Nearest Neighbor Estimates
2010
Relevance feedback has been adopted by most recent Content Based Image Retrieval systems to reduce the semantic gap that exists between the subjective similarity among images and the similarity measures computed in a given feature space. Distance-based relevance feedback using nearest neighbors has been recently presented as a good tradeoff between simplicity and performance. In this paper, we analyse some shortages of this technique and propose alternatives that help improving the efficiency of the method in terms of the retrieval precision achieved. The resulting method has been evaluated on several repositories which use different feature sets. The results have been compared to those obt…
Using a Computerised Corpus in the Construction of a Bilingual Phraseological Dictionary
2016
It is generally acknowledged that one of the main purposes of bilingual dictionaries is to provide learners with relevant and sufficient information about the grammatical, lexical and phraseological units of a language (Yong and Peng 2007: 20). Furthermore, this must be done in a way that is both convenient and comprehensible for very specific kinds of users (Cabre 2007: 80–81; Pecman 2008: 205), namely, non-native speakers who are still developing their linguistic and discourse competence but who have not fully attained the intuitive ability to tackle major grammatical issues. It follows that this kind of learner cannot rely on previous discourse experience and sociolinguistic training in …
UDP flows in Cognitive Radios with Channel Aggregation and Fragmentation: A Test-bed Based Evaluation
2018
Channel aggregation (CA) and channel fragmentation (CF) have been studied extensively in cognitive radios (CRs) for many years. However, a test-bed evaluation for such techniques at flow level is still open. In this study, employing National Instruments devices, a test-bed is set up to evaluate the performance of UDP flows for CRs with CA and CF, considering the aspects of blocking, preemption, and throughput in probability. The measurements clearly show that there are performance improvements in applying CA and CF in CRs for UDP flows.
Evaluating State-Based Intention Recognition Algorithms against Human Performance
2014
In this paper, we describe a novel intention recognition approach based on the representation of state information in a cooperative human-robot environment. We compare the output of the intention recognition algorithms to those of an experiment involving humans attempting to recognize the same intentions in a manufacturing kitting domain. States are represented by a combination of spatial relationships in a Cartesian frame along with cardinal direction information. Based upon a set of predefined high-level states relationships that must be true for future actions to occur, a robot can use the approaches described in this paper to infer the likelihood of subsequent actions occurring. This wo…
Enforcing Conceptual Modeling to improve the understanding of human genome
2010
It is widely accepted that the use of Conceptual Modeling techniques in modern Software Engineering leads to a more accurate description of the problem domain. The application of these techniques in the context of challenging domains as the human genome is a fascinating task. The relevant biological concepts should be properly addressed through the creation of the corresponding conceptual schema. This schema will improve the description of the global process followed from a DNA sequence to a fully functional protein. Once the conceptual model is established, the corresponding database is created. The database is intended to act as a unified repository of integrated information that will all…
Classification Boundary Approximation by Using Combination of Training Steps for Real-Time Image Segmentation
2007
We propose a method of real-time implementation of an approximation of the support vector machine decision rule. The method uses an improvement of a supervised classification method based on hyperrectangles, which is useful for real-time image segmentation. We increase the classification and speed performances using a combination of classification methods: a support vector machine is used during a pre-processing step. We recall the principles of the classification methods and we evaluate the hardware implementation cost of each method. We present our learning step combination algorithm and results obtained using Gaussian distributions and an example of image segmentation coming from a part …
Web Services Specific Security Standards
2014
Abstract In this paper are described the aspects regarding the security within OGSA framework, introducing WS-Security standard – OASIS standard for Web Services security. There are approached the security aspects of the OGSA environment for the delivered architectures P2P – ‘Peer-to-Peer’ and there are presented the recent initiatives for creating a specific and adapted environment OGSA for the applications P2P and the specific security demands of these transactions. Furthermore, there are exposed aspects regarding the mobility of services and resources in the P2P context, with the conditions of applying WSRF framework, derived from OGSA to the P2P environments, SOA processes in P2P enviro…