Philip Siegmann

Philip Siegmann
University of Alcalá | UAH · Department of Signal and Communications Theory

About

49
Publications
7,631
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
526
Citations
Additional affiliations
January 2012 - present
The University of Sheffield
January 2012 - present
Michigan State University
January 2007 - December 2011
Universidad de Alcalá

Publications

Publications (49)
Article
Numerical simulation plays an vital role in mechanical engineering, as it allows the prediction of the mechanical behavior of a component, contributing to the improvement of its performance and the optimization of the design. However, before using the numerical model’s valuable information, its reliability must be verified in a process called valid...
Article
Full-text available
In this work, the evolution of the fine particulate air pollution (of size below one μm) produced by the vehicles when driving along several roads of Madrid is studied. Measurements were taken with portable near real-time sensors of Diffusion Charging (DC) and Photoelectric Charging (PC) while driving along the roads. The obtained measurement profi...
Article
A new approach to perform 2D Digital Image Correlation (DIC) on objects that are subjected to large out-of-plane displacements is presented. It employs out-of-plane information to distort the speckle images of the reference and the deformed surface, increasing their similarity and therefore their sub-set cross-correlation peaks. The new approach is...
Article
Two ways of determining Bridgman’s parameters are presented to estimate the equivalent Bridgman stress–strain (BSS) curve after the onset of necking in cylindrical specimens. The accurate experimental determination of the minimum necking radius, rN, and the radius of curvature of the necking, RN, are considered to be the main problems in applying B...
Article
Full-text available
The ambient air pollution of nano- and micrometric sized particles produced during a rastering process is measured and analyzed together with the topographic measurements of the rastered surface on sheets of stainless steel samples. The rastering process performed consisted of carrying out ablation with consecutive nanosecond infrared laser pulses...
Article
In many engineering applications, the measurement of displacements maps in all three spatial directions over the surface of a loaded object is often required, such an example is, structural testing or manufacturing quality control. At present, for this proposes, typically 3-dimensional digital image correlation (3D-DIC) is often used. This techniqu...
Article
An improved measurement method and an automatic calibration procedure are proposed for a combined 2D Digital Image Correlation and Fringe Projection system that allows measuring in- and out-of-plane displacement maps with only one image at each deformation stage of a specimen. The proposed method increases the accuracy and range of the out-of-plane...
Article
A low-cost approach for three-dimensional (3-D) full-field displacement measurement is applied for the analysis of large displacements involved in two different mechanical events. The method is based on a combination of fringe projection and two-dimensional digital image correlation (DIC) techniques. The two techniques have been employed simultaneo...
Conference Paper
An optical non-contact and full-field system that allows large displacement measurements in x-, y- and z-direction is presented. The system combines 2-dimentional digital image correlation (for in-plane measurements) and fringe projection (for out-of-plane displacements) and uses only one camera. The in- and out-of-plane displacements are obtained...
Article
Full-text available
An approach for the measurement of surface displacement fields in three dimensions is presented based on the combination of two-dimensional digital image correlation with fringe projection. Only a single RGB image is required at each deformation state, thereby allowing real-time data acquisition, which is achieved using red speckle and projected bl...
Article
The combination of fringe projection (FP) and two-dimensional digital image correlation (2D-DIC) has been proposed in previous work [1] as an alternative method to obtain displacement maps in the three spatial directions. However, if a telecentric lens is not employed in the experimental setup, the in-plane displacements obtained with 2D-DIC are in...
Chapter
Most of the existing algorithms used for processing phase-shifted photoelastic data attempt to compute the unambiguous or demodulated isoclinic map in order to obtain the unambiguous or continuous isochromatic map. However, in some cases experiments on engineering components yield isoclinic maps that are severely corrupted due to the interaction be...
Article
Full-text available
A method is presented that allows real-time three-dimensional displacement maps to be obtained for deformable objects using a single color camera and a color fringe projector. The acquired images have speckle and fringe information embedded in them, which are separated using the R, G, and B color signals from a color CCD camera to permit the indepe...
Article
In the current paper a new method for calculating the stress intensity factor from isochromatic data is proposed. The method is based on the calculation of a map of the retardation using only the light- and dark-field images of a crack from a circular polariscope. The experimental retardation is compared with the theoretical one predicted by Wester...
Article
A new method of reducing the computational load in decision functions provided by a support vector classification machine is studied. The method exploits the geometrical relations when the kernels used are based on distances to obtain bounds of the remaining decision function and avoids to continue calculating kernel operations when there is no cha...
Article
Full-text available
The computation of a continuous map of isochromatic fringe order from an isochromatic phase map or relative retardation based on a photoelastic fringe pattern is a difficult task, particularly when the direction of the principal stress is ambiguous. This happens in most experiments and introduces abrupt changes in the slope of the computed relative...
Article
Full-text available
Kriging is an estimation technique that has been proved useful in image processing since it behaves, under regular sampling, as a convolution. The uncertainty obtained with kriging has also been shown to behave as a convolution for the case of regular sampling. The convolution kernel for the uncertainty exclusively depends on the spatial correlatio...
Article
Full-text available
A novel experimental approach for the calculation of stress intensity factors from the analysis of photoelastic images is presented. The method is derived from the well-established six image phase-stepping method but only two images are used to obtain the retardation angle. To calculate KI and KII a set of discrete data points are collected from th...
Conference Paper
Generally, in most traffic sign recognition systems based on image processing, the recognition process is performed individually, which means that every traffic sign must be isolated from the background, and from other traffic signs, before the object goes into the recognition process. When it comes to a traffic sign array, sometimes the previous b...
Conference Paper
This paper describes the evaluation of the characteristics of a real automatic traffic sign detection system. The objective of this review is to provide the basis of quality of a whole system, which is capable of identifying the different signs that can be found in route. At the moment, our work is concerned with the developing of an inventory syst...
Article
In the first part, we present a simple Probabilistic Source Attribution (PSA) procedure, which allows an estimate of the percentage of the contribution of previously defined sources to the total particulate air pollution determined by a simple field measurement. Four kinds of air pollution sources of small particles (size in the nanometre range, ce...
Article
Full-text available
This paper is a study of the influences of the different parameters which affect the photometric evaluation of light-emitting surfaces (due to reflection or self-emission) when a conventional color digital camera is used. The overall purpose of this paper is to evaluate the luminance and the reflectivity of the vertical traffic sign with the camera...
Conference Paper
In many traffic sign recognition systems, one of the main tasks is the classification of the shape of the blob, which is intended to simplify the recognition process. In this paper, we have developed a new shape classification algorithm based on Support Vector Machines classifiers and the FFT of the signature of the blob. The FFT of the signature y...
Conference Paper
Full-text available
One of the main characteristics of a video surveillance system is its reliability. To this end, it is needed that the images captured by the videocameras are an accurate representation of the scene. Unfortunately, some activities can make the proper operation of the cameras fail, distorting in some way the images which are going to be processed. Wh...
Conference Paper
Full-text available
This paper deals with the problem of estimating the following road sign parameters: height, dimensions, visibility distance and partial occlusions. This work belongs to a framework whose main applications involve road sign maintenance, driver assistance, and inventory systems. From this paper we suggest a multisensory system composed from two camer...
Conference Paper
Full-text available
In the design of support vector machines an important step is to select the optimal hyperparameters. One of the most used estima- tors of the performance is the Radius-Margin bound. Some modifications of this bound have been made to adapt it to soft margin problems, giv- ing a convex optimization problem for the L2 soft margin formulation. However,...
Conference Paper
Full-text available
The use of support vector machines for multi-category prob- lems is still an open field to research. Most of the published works use the one-against-rest strategy, but with a one-against-one approach re- sults can be improved. To avoid testing with all the binary classifiers there are some methods like the Decision Directed Acyclic Graph based on a...
Conference Paper
Full-text available
A fast method for the recognition and classification of informational traffic signs is presented in this paper. The aim is to provide an efficient framework which could be easily used in inventory and guidance systems. The process consists of several steps which include image segmentation, sign detection and reorientation, and finally traffic sign...
Article
This paper deals with traffic signs detection in natural environments. In this type of conditions, neither lighting conditions nor the position and orientation of signs can be controlled and, in addition, traffic signs can be occluded by other noisy objects. In this paper we have developed a new algorithm of artificial vision oriented to traffic si...
Article
In the present paper we propose an automated low cost method for evaluating the visibility of traffic signs. Since the traffic signs may present difficulties to be seen at night and whose main propose is to advice the motorists, we decided to do the measurement at night, within a car and using the headlamps as illumination sources. In this way we e...
Article
Full-text available
In this paper we present a correlation-based matching method for traffic sign shape classification. Our purpose is to offer a robust and reliable framework which can be used in numerous applications like driver assistance systems. The shape classification is scale, translation and rotation invariant. The process involves obtaining essential feature...
Article
New algorithms are proposed for processing wrapped isochromatic and isoclinic fringe data generated by the digital photoelastic technique of phase-stepping. The new algorithms are based on processing areas rather than individual pixels to demodulate the data and employing quality assessments of the data to guide the unwrapping procedure. Comparison...
Article
Full-text available
This paper proposes a new recognition algorithm of mandatory traffic sings using the Hausdorff distance. This algorithm has been designed to detect arrows on traffic signs, especially direction signs. The arrows on these mandatory signs appear in a multitude of different forms and positions. Due to this variety this algorithm uses a structural appr...
Article
http://www.uah.es Abstract: We present an automated low cost method for evaluating the visibility of traffic signs. For this propose we define a parameter which evaluates how road signs are seen by drivers at night. Thus, the evaluation is done from inside a vehicle, using the headlamps as light sources and a colour digital camera to capture the si...
Article
Conventional microscopy techniques, such as atomic force microscopy (AFM), scanning electron microscopy (SEM), and confocal microscopy (CM) are not suitable for on-line surface inspection of fine metallic wires. In the recent years, some optical techniques have been developed to be used for those tasks. However, they need a rigorous validation. In...
Article
The quality of the surface of metallic wires is relevant for different applications. The reflection of a laser beam on the surface of a metallic cylindrical wire provides an efficient way to inspect the quality of its surface. Our interest is focused in the detection of axially oriented defects, which are the most relevant for the wire drawing proc...
Article
Several studies regarding particulate matter in air pollution have been performed in Mexico City, but none have focused on environment exposure to particle-bound polycyclic aromatic hydrocarbons (PPAH), which are related to the occurrence of cardiopulmonary diseases and mortality. On this account, this study presents measurements of personal exposu...
Article
NOVELTY - The contactless optoelectronic device comprises a light unit, a capture unit and a signal processor, to detect, distinguish and spatially locate surface detects and topographic variation in the shape. USE - For detecting surface defects on cylinders, metal wires, cables. ADVANTAGE - none given.
Article
We present an analytical model to obtain the different pattern in far field of a metallic, thick slit based on the Geometrical Theory of Diffraction. The edges of the slit are modelled as semicylinders. We have considered that the thickness of the slit is sufficiently small compared to the width, so that the influence of multiple reflections betwee...
Article
Full-text available
We have developed a prototype for in-line detection of surface defects in metallic wires, specially for scratches. A simple geometrical relationship between surface topography and conical reflection, permits to correlate the defects with intensity patterns in a simple way. The presented apparatus consists basically in a grating-divided laser beam i...
Article
In this report a classification of the main surface structures found on fine metallic wires is carried out (between similar to 20 and 500 mum in diameter). For this, we have analyzed a series of wires of different metallic materials, diameters and production environments by scanning electron microscopy, atomic force microscopy, and confocal microsc...
Article
Full-text available
In industrial applications of thin metallic wires it is important to characterize the surface defects of the wires. We present an optical technique for the automatic detection of surface defects on thin metallic wires (diameters, 50-2000 microm) that can be used in on-line systems for surface quality control. This technique is based on the intensit...
Article
Full-text available
Optical geometrical conical diffraction may be used for on-line detection of surface defects on thin metallic wires. This method has been compared with Scanning Electron Microscopy measurements of the defects.
Article
Full-text available
En la presente Memoria de Tesis Doctoral presentamos por un lado, un estudio de las causas más probables por las que aparecen los defectos encontrados en la superficie de hilos metálicos finos, del orden de 30 a 600 micras de diámetro, y una catalogación de los mismos, y por otro lado, un prototipo pre-industrial que permite un control de calidad,...

Network

Cited By