<p>Den här uppsatsen är en litteraturstudie som behandlar problemet självdestruktivitet ur ett sociologiskt perspektiv. Jag har valt detta för att det är ett aktuellt problem och det är intressant att se det ur en sociologisk synvinkel istället för en psykologisk som kanske är vanligare att inta. Vilka sociologiska faktorer kan spela in gällande detta problem? Den litteratur som har legat till bakgrund för studien behandlar vilka som skadar sig, varför de gör det och olika definitioner samt vilka avgränsningar som bör göras för att ringa in fenomenets innebörd. Att skära, bränna och slå sig själv visar på ett självdestruktivt beteende och en orsak kan vara depression eller ångest.</p><p>Problemställningen som jag sökte ett svar på löd: Vilka ungdomar är det som skadar sig och varför? I den teoretiska genomgången så ligger fokus på kategorierna modernitet, kropp och ungdom. Utifrån detta tas olika sociologiska begrepp upp och analyseras i diskussionsfasen. I undersökningen så har jag bl.a. kommit fram till att dagens konsumtionssamhälle samt individualiseringen är en sannolikt bidragande faktor till att vissa unga människor utvecklar ett självdestruktivt handlande.</p> / <p>This study is an attempt to adress the problem of self-destructive behaviour from a sociological point of view. I feel that this is an important isssue in contemporary society, and that a sociological perspecitve may have something to offer that the more common psychological perspective may miss out on. The literature upon which the study is based deals with questions such as: What definition of the problem is most suitable? What are the characteristics of self-destructive behaviour and why do people hurt themself deliberately?</p><p>The specific question I approached was: Who are the young people that hurt themselves and why? The theoretical framework focuses on modernity, body and youth, and I make use of sociological concepts in the discussion. Some of my conclusions were that the consumeristic society of today and the individualization could be relevant factors in developing a self-destructive pattern.</p>

Das Parallel-Seismik-Verfahren dient vor allem der nachträglichen Längenmessung von Fundamentpfählen oder ähnlichen Elementen zur Gründung von Bauwerken. Eine solche Messung wird beispielsweise notwendig, wenn ein Gebäude verstärkt, erhöht oder anders als bisher genutzt werden soll, aber keine Unterlagen mehr über die Fundamente vorhanden sind. Das Messprinzip des schon seit einigen Jahrzehnten bekannten Verfahrens ist relativ einfach: Auf dem Pfahlkopf wird meist durch Hammerschlag eine Stoßwelle erzeugt, die durch den Pfahl nach unten läuft. Dabei wird Energie in den Boden abgegeben. Die abgestrahlten Wellen werden von Sensoren in einem parallel zum Pfahl hergestellten Bohrloch registriert. Aus den Laufzeiten lassen sich die materialspezifischen Wellengeschwindigkeiten im Pfahl und im Boden sowie die Pfahllänge ermitteln. Bisher wurde meist ein sehr einfaches Verfahren zur Datenauswertung verwendet, das die Länge der Pfähle systematisch überschätzt. In der vorliegenden Dissertation wurden die mathematisch-physikalischen Grundlagen beleuchtet und durch Computersimulation die Wellenausbreitung in Pfahl und Boden genau untersucht. Weitere Simulationen klärten den Einfluss verschiedener Mess- und Strukturparameter, beispielsweise den Einfluss von Bodenschichtung oder Fehlstellen im Pfahl. So konnte geklärt werden, in welchen Fällen mit dem Parallel-Seismik-Verfahren gute Ergebnisse erzielt werden können (z. B. bei Fundamenten in Sand oder Ton) und wo es an seine Grenzen stößt (z. B. bei Gründung im Fels). Auf Basis dieser Ergebnisse entstand ein neuer mathematischer Formalismus zur Auswertung der Laufzeiten. In Verbindung mit einem Verfahren zur Dateninversion, d. h. der automatischen Anpassung der Unbekannten in den Gleichungen an die Messergebnisse, lassen sich sehr viel genauere Werte für die Pfahllänge ermitteln als mit allen bisher publizierten Verfahren. Zudem kann man nun auch mit relativ großen Abständen zwischen Bohrloch und Pfahl (2 - 3 m) arbeiten. Die Methode wurde an simulierten Daten ausführlich getestet. Die Messmethode und das neue Auswerteverfahren wurden in einer Reihe praktischer Anwendungen getestet – und dies fast immer erfolgreich. Nur in einem Fall komplizierter Fundamentgeometrie bei gleichzeitig sehr hoher Anforderung an die Genauigkeit war schon nach Simulationen klar, dass hier ein Einsatz nicht sinnvoll ist. Dafür zeigte es sich, dass auch die Länge von Pfahlwänden und Spundwänden ermittelt werden kann. Die Parallel-Seismik-Methode funktioniert als einziges verfügbares Verfahren zur Fundamentlängenermittlung zugleich in den meisten Bodenarten sowie an metallischen und nichtmetallischen Fundamenten und kommt ohne Kalibrierung aus. Sie ist nun sehr viel breiter einsetzbar und liefert sehr viel genauere Ergebnisse. Die Simulationen zeigten noch Potential für Erweiterungen, zum Beispiel durch den Einsatz spezieller Sensoren, die zusätzliche Wellentypen empfangen und unterscheiden können. / The Parallel Seismic (PS) method is used for determination of the unknown or undocumented depth/length of unknown foundations, mostly piles. Parallel Seismic is an established but rather not commonly used geophysical technique, which has been developed several decades ago. Currently, this method is standardized in France and included in the method catalog of the US FHWA. The principle behind PS is quite simple: an impulse is generated on top of the pile by a hammer stroke, generating elastic waves (mainly compressional) traveling downward through the pile. Due to the high impedance contrast between pile and soil, the main part of the energy remains in the pile, but some is transmitted as guided waves into the surrounding soil. After reaching the pile toe, transmitted/diffracted waves of nearly spherical front are generated. These waves are recorded by sensors (hydrophones or geophones) in a nearby borehole. From the first arrival times registered at the sensors, the apparent wave velocity is calculated, which is different above the pile toe (pile velocity) and below (soil velocity). In the conventional data analysis, the pile length is estimated based on the intersection of the two travel time branches, leading to a systematic overestimation of the length of the pile. This thesis provides a systematic treatise of the mathematical and physical foundations of wave propagation in piles and soil. Extensive numerical simulations and parametric studies have been carried out to investigate the nature of the wave-field and influence of measurement and structural parameters. The results revealed the range of applicability of Parallel Seismic, but also some limitations, e. g. in the case of rock socketed foundations or piles containing flaws. A new mathematical algorithm for data interpretation was developed based on the simulation results, which takes into account the soil layers and the borehole inclination. This novel data interpretation scheme was used in combination with different data inversion methods. A comparison of the results showed that the commonly used Levenberg-Marquardt type least squares approach gives sufficiently accurate estimations in most common scenarios. The VFSA (very fast simulated annealing) method offers some advantages (e. g. avoiding local minima under certain conditions) but is much more time consuming. The new interpretation method was successfully validated using several sets of simulated data. It proved to be not only more accurate than all other available methods, but also to extend the maximum allowable pile-borehole distance to 2 – 3 m. Besides the numerical study, several field investigations have been carried out for the purpose of this study and also in the framework of real world projects. The foundation types included secant pile walls and sheet piles. The method performed successfully in all cases but one: a highly accurate determination of the connection of a T-shaped footing. In this particular case, the inapplicability of the method was concluded after some preliminary simulations, thus avoiding unnecessary costs to the client. Performing simulations prior to the actual testing is recommended in dealing with all non-standard cases. Today, Parallel Seismic is the only method applicable on metallic and non metallic foundations which can be used without calibration. It has the largest range of all borehole methods.

Den här uppsatsen är en litteraturstudie som behandlar problemet självdestruktivitet ur ett sociologiskt perspektiv. Jag har valt detta för att det är ett aktuellt problem och det är intressant att se det ur en sociologisk synvinkel istället för en psykologisk som kanske är vanligare att inta. Vilka sociologiska faktorer kan spela in gällande detta problem? Den litteratur som har legat till bakgrund för studien behandlar vilka som skadar sig, varför de gör det och olika definitioner samt vilka avgränsningar som bör göras för att ringa in fenomenets innebörd. Att skära, bränna och slå sig själv visar på ett självdestruktivt beteende och en orsak kan vara depression eller ångest. Problemställningen som jag sökte ett svar på löd: Vilka ungdomar är det som skadar sig och varför? I den teoretiska genomgången så ligger fokus på kategorierna modernitet, kropp och ungdom. Utifrån detta tas olika sociologiska begrepp upp och analyseras i diskussionsfasen. I undersökningen så har jag bl.a. kommit fram till att dagens konsumtionssamhälle samt individualiseringen är en sannolikt bidragande faktor till att vissa unga människor utvecklar ett självdestruktivt handlande. / This study is an attempt to adress the problem of self-destructive behaviour from a sociological point of view. I feel that this is an important isssue in contemporary society, and that a sociological perspecitve may have something to offer that the more common psychological perspective may miss out on. The literature upon which the study is based deals with questions such as: What definition of the problem is most suitable? What are the characteristics of self-destructive behaviour and why do people hurt themself deliberately? The specific question I approached was: Who are the young people that hurt themselves and why? The theoretical framework focuses on modernity, body and youth, and I make use of sociological concepts in the discussion. Some of my conclusions were that the consumeristic society of today and the individualization could be relevant factors in developing a self-destructive pattern.

Non-destructive methods of material interrogation are used to locate hidden explosives and thwart terrorism attempts. In one such method materials are bombarded with neutrons which react with the nuclei of the atoms within causing a de-excitation process emitting a gamma-ray. The spectrum displayed by the collection of these gamma-rays gives valuable information regarding the material’s elemental make-up. It has been hypothesized that gamma-rays from neutron-induced gamma-ray reactions on light elements with atomic numbers less than 20, including most of the gamma-rays of interest in explosives detection, are Doppler-broadened. This thesis focuses on the gamma ray spectra from the 4438 keV gamma ray in the 12C (n, n’γ) reaction wherein Doppler broadening was investigated. A graphite sample was exposed to 14 MeV neutrons and the 12C gamma ray spectra collected using an HPGe detector positioned at four different angles with respect to the neutron beam; near 00, 450, 900 and 1350. No other experimental parameter was changed. The resultant gamma ray spectra indicated Doppler broadening had occurred.

Mechanical waves provide information about the stiffness and the condition of a medium; thus, changes in medium conditions can be inferred from changes in wave velocity and attenuation. Non-destructive testing (NDT) methods based on ultrasonic waves are often more economical, practical and faster than destructive testing. Multichannel analysis of surface waves (MASW) is a well-established surface wave method used for determination of the shear-wave profile of layered medium. The MASW test configuration is also applicable to assess the condition of concrete elements using appropriate frequency range. Both attenuation and dispersion of ultrasonic waves can be evaluated by this technique. In ultrasonic testing, the characterization of a medium requires the precise measurement of its response to ultrasonic pulses to infer the presence of defects and boundary conditions. However, any ultrasonic transducer attached to a surface affects the measured response; especially at high frequencies. On the other hand, ultrasonic transducers available for engineering application are mostly used to measure wave velocities (travel time method). Therefore, these transducers do not have a flat response in the required frequency range. Moreover, in the case of full-waveform methods, the recorded signals should be normalized with respect to the transfer functions of the transducers to obtain the real response of the tested specimen. The main objective of this research is to establish a comprehensive methodology based on surface wave characteristics (velocity, attenuation and dispersion) for condition assessment of cemented materials with irregular defects. To achieve the major objective, the MASW test configuration is implemented in the ultrasonic frequency range. The measured signals are subjected to various signal processing techniques to extract accurate information. In addition, a calibration procedure is conducted to determine the frequency response functions (FRF) of the piezoelectric accelerometers outside their nominal frequency range. This calibration is performed using a high-frequency laser vibrometer. This research includes three main studies. The first study introduces the calibration approach to measure the FRFs of the accelerometers outside of their flat frequency range. The calibrated accelerometers are then used to perform MASW tests on a cemented-sand medium. The original signals and the corrected ones by eliminating the effect of the FRFs are used to determine material damping of the medium. Although, the damping ratios obtained from different accelerometers are not same, the values from the corrected signals are found closer to the characteristic damping value compared to those from the uncorrected signals. The second study investigates the sensitivity of Rayleigh wave velocity, attenuation coefficient, material damping and dispersion in phase velocity to evaluate the sensitivity of these characteristics to the damage quantity in a medium. The soft cemented-sand medium is preferred as the test specimen so that well-defined shaped defects could be created in the medium. MASW test configuration is implemented on the medium for different cases of defect depth. The recorded signals are processed using different signal processing techniques including Fourier and wavelet transforms and empirical mode decomposition to determine the surface wave characteristics accurately. A new index, ‘dispersion index’, is introduced which quantifies the defect based on the dispersive behaviour. All surface wave characteristics are found capable of reflecting the damage quantity of the test medium at different sensitivity levels. In the final study, the condition assessment of six lab-scale concrete beams with different void percent is performed. The beam specimens involving Styrofoam pellets with different ratios are tested under ultrasonic and mechanical equipment. The assessment produce established in the second study with well-defined defects is pursed for the beams with irregular defects. Among the characteristics, attenuation, P and R-wave velocities and dispersion index are found as the promising characteristics for quantifying the defect volume.

La inspección térmica basada en radiación infrarroja provee medidas rápidas, sin contacto y desde una única posición. Su principio básico es el control y estimación de diferencias de temperaturas en una superficie. Conscientes de su aplicabilidad potencial en la evaluación no destructiva ni invasiva, se planteó como objetivo general el efectuar contribuciones al conocimiento y la técnica que, además, tuviesen visos de aplicación real. Ante la variedad de sistemas termográficos existentes, se detectan carencias de unos respecto de otros que limitan su aplicabilidad. Surge la necesidad de compararlos y con ello la definición de parámetros que valoren los beneficios de cada uno de ellos. Igualmente, se requiere una automatización de los procesos de toma de decisión para eludir la subjetividad en el análisis de las secuencias térmicas. Se aportan diferentes propuestas basadas en métodos estadísticos y técnicas transformadas que procuran imágenes únicas donde todos los defectos detectables son localizados. / Thermal inspection based on infrared radiation provides fast and contactless measurements from one location. Its basic principle is the control and assessment of temperature differences on a surface. Given its potential applicability for non-destructive and non-invasive evaluation and testing, the main goal of this thesis is the contribution to the knowledge and technique state of the art, always from a real-application point of view. Considering the wide variety of thermographic systems, several lacks have been detected in some systems limiting their use. It could be interesting to compare these systems and, hence, to establish a set of parameters that objectively evaluates the benefits of any of them. In addition, an automation of the decision process should be provided to avoid the human subjectivity in the analysis of thermographic sequences. Here, different proposals based on statistical methods and data transforms are detailed. They provide unique images where defects are highlighted.

This project is based on Artificial Intelligence (A.I) and Digital Image processing (I.P) for automatic condition monitoring of sleepers in the railway track. Rail inspection is a very important task in railway maintenance for traffic safety issues and in preventing dangerous situations. Monitoring railway track infrastructure is an important aspect in which the periodical inspection of rail rolling plane is required.Up to the present days the inspection of the railroad is operated manually by trained personnel. A human operator walks along the railway track searching for sleeper anomalies. This monitoring way is not more acceptable for its slowness and subjectivity. Hence, it is desired to automate such intuitive human skills for the development of more robust and reliable testing methods. Images of wooden sleepers have been used as data for my project. The aim of this project is to present a vision based technique for inspecting railway sleepers (wooden planks under the railway track) by automatic interpretation of Non Destructive Test (NDT) data using A.I. techniques in determining the results of inspection.

The motivation for this thesis work is the need for improving reliability of equipment and quality of service to railway passengers as well as a requirement for cost-effective and efficient condition maintenance management for rail transportation. This thesis work develops a fusion of various machine vision analysis methods to achieve high performance in automation of wooden rail track inspection.The condition monitoring in rail transport is done manually by a human operator where people rely on inference systems and assumptions to develop conclusions. The use of conditional monitoring allows maintenance to be scheduled, or other actions to be taken to avoid the consequences of failure, before the failure occurs. Manual or automated condition monitoring of materials in fields of public transportation like railway, aerial navigation, traffic safety, etc, where safety is of prior importance needs non-destructive testing (NDT).In general, wooden railway sleeper inspection is done manually by a human operator, by moving along the rail sleeper and gathering information by visual and sound analysis for examining the presence of cracks. Human inspectors working on lines visually inspect wooden rails to judge the quality of rail sleeper. In this project work the machine vision system is developed based on the manual visual analysis system, which uses digital cameras and image processing software to perform similar manual inspections. As the manual inspection requires much effort and is expected to be error prone sometimes and also appears difficult to discriminate even for a human operator by the frequent changes in inspected material. The machine vision system developed classifies the condition of material by examining individual pixels of images, processing them and attempting to develop conclusions with the assistance of knowledge bases and features.A pattern recognition approach is developed based on the methodological knowledge from manual procedure. The pattern recognition approach for this thesis work was developed and achieved by a non destructive testing method to identify the flaws in manually done condition monitoring of sleepers.In this method, a test vehicle is designed to capture sleeper images similar to visual inspection by human operator and the raw data for pattern recognition approach is provided from the captured images of the wooden sleepers. The data from the NDT method were further processed and appropriate features were extracted.The collection of data by the NDT method is to achieve high accuracy in reliable classification results. A key idea is to use the non supervised classifier based on the features extracted from the method to discriminate the condition of wooden sleepers in to either good or bad. Self organising map is used as classifier for the wooden sleeper classification.In order to achieve greater integration, the data collected by the machine vision system was made to interface with one another by a strategy called fusion. Data fusion was looked in at two different levels namely sensor-level fusion, feature- level fusion. As the goal was to reduce the accuracy of the human error on the rail sleeper classification as good or bad the results obtained by the feature-level fusion compared to that of the results of actual classification were satisfactory.

Since the last decade the problem of surface inspection has been receiving great attention from the scientific community, the quality control and the maintenance of products are key points in several industrial applications.The railway associations spent much money to check the railway infrastructure. The railway infrastructure is a particular field in which the periodical surface inspection can help the operator to prevent critical situations. The maintenance and monitoring of this infrastructure is an important aspect for railway association.That is why the surface inspection of railway also makes importance to the railroad authority to investigate track components, identify problems and finding out the way that how to solve these problems. In railway industry, usually the problems find in railway sleepers, overhead, fastener, rail head, switching and crossing and in ballast section as well. In this thesis work, I have reviewed some research papers based on AI techniques together with NDT techniques which are able to collect data from the test object without making any damage. The research works which I have reviewed and demonstrated that by adopting the AI based system, it is almost possible to solve all the problems and this system is very much reliable and efficient for diagnose problems of this transportation domain. I have reviewed solutions provided by different companies based on AI techniques, their products and reviewed some white papers provided by some of those companies. AI based techniques likemachine vision, stereo vision, laser based techniques and neural network are used in most cases to solve the problems which are performed by the railway engineers.The problems in railway handled by the AI based techniques performed by NDT approach which is a very broad, interdisciplinary field that plays a critical role in assuring that structural components and systems perform their function in a reliable and cost effective fashion. The NDT approach ensures the uniformity, quality and serviceability of materials without causing any damage of that materials is being tested. This testing methods use some way to test product like, Visual and Optical testing, Radiography, Magnetic particle testing, Ultrasonic testing, Penetrate testing, electro mechanic testing and acoustic emission testing etc. The inspection procedure has done periodically because of better maintenance. This inspection procedure done by the railway engineers manually with the aid of AI based techniques.The main idea of thesis work is to demonstrate how the problems can be reduced of thistransportation area based on the works done by different researchers and companies. And I have also provided some ideas and comments according to those works and trying to provide some proposal to use better inspection method where it is needed.The scope of this thesis work is automatic interpretation of data from NDT, with the goal of detecting flaws accurately and efficiently. AI techniques such as neural networks, machine vision, knowledge-based systems and fuzzy logic were applied to a wide spectrum of problems in this area. Another scope is to provide an insight into possible research methods concerning railway sleeper, fastener, ballast and overhead inspection by automatic interpretation of data.In this thesis work, I have discussed about problems which are arise in railway sleepers,fastener, and overhead and ballasted track. For this reason I have reviewed some research papers related with these areas and demonstrated how their systems works and the results of those systems. After all the demonstrations were taking place of the advantages of using AI techniques in contrast with those manual systems exist previously.This work aims to summarize the findings of a large number of research papers deploying artificial intelligence (AI) techniques for the automatic interpretation of data from nondestructive testing (NDT). Problems in rail transport domain are mainly discussed in this work. The overall work of this paper goes to the inspection of railway sleepers, fastener, ballast and overhead.

Gradient Enhanced Piezoelectric Actuators (GEPAC) are thin piezoelectric plates embedded between two composites layers having different thermal properties. Compared to standard unimorph bending actuators, GEPACs offer superior performances for operations at low frequencies. Potential applications are in the area of multifunctional aircraft skins. In practice, delaminations or debonding within the actuator itself can occur, and it is highly desirable to develop an ultrasonic nondestructive method to monitor the integrity of the actuator in real time. For this study, the composite material is unidirectional Kevlar-epoxy, with fibers oriented at 90 and 0 for the upper and lower layers to achieve different coefficient of thermal expansion. A thin PZT plate is inserted between the two layers, and extended copper foil is used for electrodes on the PZT. The first objective of the research is to demonstrate that, by using segmented electrodes, one can simultaneously launch an ultrasonic pulse (1 MHz) for NDE testing while the actuator is undergoing low frequency actuation (less than 100 Hz). The second objective is to show that the ultrasonic signal can be used to detect damage induced during fatigue testing of the actuator. The third objective is to use the technique to monitor the integrity of a composite plate containing several embedded GEPACs.