Search results for "pattern"
showing 10 items of 4203 documents
Reliable polygonal approximations of imaged real objects through dominant point detection
1998
Abstract The problem of dominant point detection is posed, taking into account what usually happens in practice. The algorithms found in the literature often prove their performance with laboratory contours, but the shapes in real images present noise, quantization, and high inter and intra-shape variability. These effects are analyzed and solutions to them are proposed. We will also focus on the conditions for an efficient (few points) and precise (low error) dominant point extraction that preserves the original shape. A measurement of the committed error (optimization error, E 0 ) that takes into account both aspects is defined for studying this feature.
Sequential Mining Classification
2017
Sequential pattern mining is a data mining technique that aims to extract and analyze frequent subsequences from sequences of events or items with time constraint. Sequence data mining was introduced in 1995 with the well-known Apriori algorithm. The algorithm studied the transactions through time, in order to extract frequent patterns from the sequences of products related to a customer. Later, this technique became useful in many applications: DNA researches, medical diagnosis and prevention, telecommunications, etc. GSP, SPAM, SPADE, PrefixSPan and other advanced algorithms followed. View the evolution of data mining techniques based on sequential data, this paper discusses the multiple …
Overview on Sequential Mining Algorithms and Their Extensions
2018
The main purpose of data mining is to extract hidden, important and nontrivial information from a database. Sequential Pattern Mining is a data mining technique that aims to obtain and analyze frequent subsequences from sequences of events or items with or without time constraint. The importance of a sequence can be measured based on different factors such as the frequency of their occurrence, their length and also their profit. The pattern mining or the discovery of important and unexpected patterns and information was first introduced in 1990 with the well-known Apriori algorithm. Then, and after many studies on frequent pattern mining, a new approach appeared: Sequential Pattern Mining. …
Hop: Histogram of patterns for human action representation
2017
This paper presents a novel method for representing actions in terms of multinomial distributions of frequent sequential patterns of different length. Frequent sequential patterns are series of data descriptors that occur many times in the data. This paper proposes to learn a codebook of frequent sequential patterns by means of an apriori-like algorithm, and to represent an action with a Bag-of-Frequent-Sequential-Patterns approach. Preliminary experiments of the proposed method have been conducted for action classification on skeletal data. The method achieves state-of-the-art accuracy value in cross-subject validation.
Time-course changes of plasma lipid levels and lipoprotein pattern after feeding in cultured sea bass, Dicentrarchus labrax L.
1988
Results of a study of plasma lipids levels and lipoprotein pattern modification during digestion in sea bass indicate that, after feeding, non-esterified fatty acids are rapidly delivered in plasma, while triglycerides reach a maximum concentration only 24 h later. The time-course change of the lipoprotein pattern shows a relationship between their concentration and the lipid class carried.
Analysis of the vertical distribution in a model of phytoplankton dynamics
2010
Phytoplankton often faces the dilemma of living in contrasting gradients of two essential resources: the light that comes from above and nutrients that are often supplied from below. In poorly mixed water columns, algae can be heterogeneously distributed, with thin layers of biomass found on the surface, in depth, or on the sediment surface. Here, we show that these patterns can result from intraspecific competition between light and nutrients. First, we present numerical solutions of a reaction-diffusion-taxis model for phytoplankton, nutrients and light. We argue that motile phytoplankton can form a thin layer under poorly mixed conditions. The numerical solution of this model indicates t…
Color degradation mapping of rock art paintings using microfading spectrometry
2021
[EN] Rock art documentation is a complex task that should be carried out in a complete, rigorous and exhaustive way, in order to take particular actions that allow stakeholders to preserve the archaeological sites under constant deterioration. The pigments used in prehistoric paintings present high light sensitivity and rigorous scientific color degradation mapping is not usually undertaken in overall archaeological sites. Microfading spectrometry is a suitable technique for determining the light-stability of pigments found in rock art paintings in a non-destructive way. Spectral data can be transformed into colorimetric information following the recommendations published by the Commission …
Mosaic floors of roman Villa del Casale: Principal component analysis on spectrophotometric and colorimetric data
2013
Abstract Spectrophotometric and colorimetric data obtained during a measurement campaign aimed at supporting the Roman "Villa del Casale" (Piazza Armerina, Sicily, Italy) conservation activities, are presented. Special attention was paid to the possible variation of the chromatic coordinates, possibly due to the interventions of cleaning, consolidation, and protection. Data have been analyzed by the Principal Component Analysis (PCA) statistical technique, with the attempt to investigate its role in data variability reduction and verify its effectiveness in interpreting the phenomena occurring on the mosaic surface of the Villa, through grouping the observations into homogenous clusters. Ef…
Pottery decoration in the Neolithic of Kaf Taht el-Ghar (Tetouan, Morocco). AGRIWESTMED Works 2012
2021
Presentamos el estudio de los restos cerámicos de la fase neolítica de Kaf Taht el-Ghar (Mechrouha, Tetuán, Marruecos), enfocado principalmente en el análisis de técnicas y patrones decorativos. Ello cuenta con el interés añadido de corresponder, en su fase antigua, a las cerámicas asociadas a las primeras evidencias de agricultura y ganadería en el Magreb Occidental, encuadradas en el tercer cuarto del VI milenio cal AC. En dichas decoraciones dominan impresiones variadas, en particular las realizadas con concha estriada y lisa, peine y de cypraea. El uso de tales técnicas podría incluir estas primeras producciones cerámicas dentro del mundo impresso-cardial de la Europa mediterránea centr…
A Generic Architectural Model Approach for Efficient Utilization of Patterns
2015
A software pattern describes the core of the solution to a problem that tends to (re-)occur in a particular environment. Such patterns are commonly used as a means to facilitate the creation of an architectural design satisfying the desired quality goals. In this chapter, the practical challenges of efficient usage of patterns in domain-specific software development are presented. The specific domain considered here is the mobile domain, for which is given a sample collection of potentially useful patterns. After that, a novel generic architectural model approach for organizing patterns is presented. In this approach, the identification of relevant patterns is considered as the process of r…