Illumination methods for optical wear detection

The paper presents some results of a study on optical wear detection. The focus of the paper is on the illumination, to optimize the contrast of the images. Various illumination methods are compared: bright field versus dark field illumination, and various kind of light sources: laser light, diffuse light and ring-light

Analysis of Energy Relations between Noise and Vibration Produced by a Low-Field MRI Device

Magnetic resonance imaging (MRI) tomography is often used for noninvasive scanning of various parts of a human body without undesirable effects present in X-ray computed tomography. In MRI devices, slices of a tested subject are selected in 3D coordinates by a system of gradient coils. The current flowing through these coils changes rapidly, which results in mechanical vibration. This vibration is significant also in the equipment working with a low magnetic field, and it causes image blurring of thin layer samples and acoustic noise significantly degrading a speech signal recorded simultaneously during MR scanning of the vocal tract. There are always negative physiological and psychological effects on a person exposed to vibration and acoustic noise. In order to minimize these negative impacts depending on intensity and time duration of exposition, we mapped relationship between energy of vibration and noise signals measured in the MRI scanning area and its vicinity

Adaptation of access networks for advanced networking technologies

Bakalárska práca sa upriamuje na služby bežiace v reálnom čase v paketových sietiach a na problémy ktoré môžu nastať pri ich chode. Konkrétne je zameraná na technológie služby VoIP. Existujú rôzne signalizačné protokoly na podporu tejto služby. Práca je primárne zameraná na veľmi rozšírený SIP protokol. Po zostavení a réžii spojenia je potrebné zaistiť prenos samotných hlasových dát. To je úlohou RTP protokolu. Táto služba, ako aj ďalšie pre ktoré je kritický čas, s narastajúcou vyťaženosťou sietí potrebuje byť často uprednostnená pred klasickými službami ako je napríklad sťahovanie súborov a iné. VoIP služba má určité požiadavky na parametre prenosu, ktoré je treba dodržať pre jej optimálnu funkciu. Sú to napríklad stratovosť paketov, zdržanie a kolísanie zdržania. Najproblematickejšie je zaistiť optimálny chod tejto služby na pomalších prenosových linkách. Preto bolo postupom času potrebné zaviesť mechanizmy, ktoré sú schopné službám v reálnom čase zaistiť dostatočnú sieťovú kapacitu pre uspokojenie koncových uživateľov. Sú to napríklad technológie integrovaných služieb alebo technológie diferencovaných služieb. V súčastnosti však technológia integrovaných služieb nie je príliš rozšírená kvôli jej neefektívnosti. Na zostavenej telefónnej sieti z dostupných komponentov v laboratóriu je prevedená analýza niektorých charakteristických prvkov a vlastností SIP protokolu. Ďalej sú zmerané a vyhodnotené základné prenosové parametre ovplyvňujúce zaistenie QoS.The bachelor thesis is focusing on the real-time services running in packet networks and problems that may arise while they are running. Specifically it is focused on the technology of VoIP service. There are many different signaling protocols to support this service. Among others, the SIP protocol is very widespread. In addition of the connection it is necessary to ensure the transmission of voice data. That is the task of the RTP protocol. This service and also others for which time is critical with increasing constraints on networks it needs to be frequently given the priority over traditional services like downloading files, and more. VoIP service has certain requirements for transmission parameters that must be followed for optimal function. They are for example, packet loss, one-way delay and delay variation. Most problematic is to ensure the optimal operation of the service on slower transmission routes. That is why it was necessary to establish mechanisms capable of real-time services to ensure sufficient network capacity to meet end user. These are, for example technologies of integrated services or differentiated services. At the present time, however, the technology of integrated services is not very widespread because of its inefficiency. On assembled telephone network made from available components in the laboratory, there are analyzed and confirmed some of the distinctive features and characteristics of the SIP protocol. Furthermore, measurements confirmed sufficient network capacity for VoIP service of the used network and parameters affecting security of the QoS have been evaluated.

Communication model using Data distribution service and communication security assessment

Diplomová práca sa zameriava na problematiku middleware vrstvy v distribuovaných systémoch. Uvádza typicky používané komunikačné protokoly a štandardy, ktoré na tejto vrstve pracujú. Jej užšie zameranie je z hľadiska teoretickej aj praktickej časti na špecifikáciu OMG DDS. Priblížené sú jej základné funkcionality a architektúra spolu s jednotlivými prvkami. V práci je taktiež popísaný RTPS protokol. Na záver teoretickej časti sú popísané existujúce implementácie štandardu OMG DDS. V praktickej časti je využitá OpenDDS 3.13 implementácia tejto špecifikácie. Otestované je jej nasadenie na rôznych platformách. V ďalšej časti je overená vlastnosť zabezpečenia prenosu dát pomocou beta verzie OMG DDS Security, ktorú táto implementácia obsahuje. Porovnaný je zabezpečený a nezabezpečený prenos. V distribuovaných systémoch je dôležité aj oneskorenie prenosu systému. Pre analýzu rôznych vplyvov na výsledné oneskorenie prenosu je v praktickej časti vytvorený DDS systém, ktorý meria oneskorenie pri rôznych nastaveniach QoS a zabezpečení. Prevedené a analyzované sú merania pri rôznych vlastnostiach prenosu. Z výsledkov meraní sú zrejme vplyvy výkonu zariadenia pri zvyšovaní veľkosti odosielaných vzoriek. Zaznamené sú rozdiely oneskorenia medzi spoľahlivým a nespoľahlivým a zabezpečeným a nezabezpečeným prenosom. Uskutočnené sú aj merania medzi 2 fyzickými zariadeniami s útočníkom a bez neho. Útok je typu MITM a zachytáva RTPS prenos ktorý mu nie je určený.The diploma thesis is focusing on middleware layer in distributed systems. It introduces typically used communication protocols and standards operating on this layer. In theoretical part it brings closer look at OMG DDS specification. This part contains fundamental functionalities of this specification along with its architecture blocks. Thesis also describes the RTPS protocol functionality. Existing implementations of OMG DDS standard are described at the end of theoretical part. OpenDDS 3.13 implementation is used in practical part of thesis. It is deployed and tested on various platforms. Next part verifies option of securing RTPS data stream using beta version of OMG DDS Security, which OpenDDS 3.13 implementation contains. Secured and unsecured data flows are being compared. Latency of data stream is also important, especially in distributed systems. DDS system, which measures latency of RTPS stream is created in practical part. Latency of this DDS system can be measured in various configurations. Difference of devices’ performance used in measurements can be clearly seen in latency results where the size of data samples is increasing. Differences of measured latency are also recognizable between reliable and unreliable and secure and unsecure RTPS stream. Part of measurements is made between 2 physical devices with and without an attacker. Type of attack is MITM and it captures RTPS flow, which does not belong to attacking machine.

Analysis of Acoustic Noise and its Suppression in Speech Recorded During Scanning in the Open-Air MRI

The paper focuses on describing three methods of noise reduction in the speech signal recorded in an open-air magnetic resonance imager (MRI) working in a weak magnetic field during human phonation for the vocal tract modelling. This paper also analyses and compares spectral properties of the acoustic noise produced by mechanical vibration of the MRI device gradient coils. Then, the experiment with mapping of noise sound pressure level (SPL) in the MRI neighbourhood is described. The changes in acoustic noise spectral properties caused by loading of the holder of the lower gradient coils by the weight of the examined person lying in the scanning area of the MRI device is evaluated too. The influence of setting of the basic scan parameters of the used MR sequence (TR and TE times) on the spectral properties of the generated acoustic noise is also analysed. The results achieved are used to create a database of initial MR scan parameters such as the filter bank for noise signal pre-processing and to design a correction filter for noise suppression in the speech signal recorded simultaneously with three-dimensional (3D) human vocal tract scanning

Skeletal muscle alkaline Pi pool is decreased in overweight-to-obese sedentary subjects and relates to mitochondrial capacity and phosphodiester content.

Defects in skeletal muscle energy metabolism are indicative of systemic disorders such as obesity or type 2 diabetes. Phosphorus magnetic resonance spectroscopy ((31)P-MRS), in particularly dynamic (31)P-MRS, provides a powerful tool for the non-invasive investigation of muscular oxidative metabolism. The increase in spectral and temporal resolution of (31)P-MRS at ultra high fields (i.e., 7T) uncovers new potential for previously implemented techniques, e.g., saturation transfer (ST) or highly resolved static spectra. In this study, we aimed to investigate the differences in muscle metabolism between overweight-to-obese sedentary (Ob/Sed) and lean active (L/Ac) individuals through dynamic, static, and ST (31)P-MRS at 7T. In addition, as the dynamic (31)P-MRS requires a complex setup and patient exercise, our aim was to identify an alternative technique that might provide a biomarker of oxidative metabolism. The Ob/Sed group exhibited lower mitochondrial capacity, and, in addition, static (31)P-MRS also revealed differences in the Pi-to-ATP exchange flux, the alkaline Pi-pool, and glycero-phosphocholine concentrations between the groups. In addition to these differences, we have identified correlations between dynamically measured oxidative flux and static concentrations of the alkaline Pi-pool and glycero-phosphocholine, suggesting the possibility of using high spectral resolution (31)P-MRS data, acquired at rest, as a marker of oxidative metabolism

<em>Les remèdes de bonne femme</em>. De la compilación de saberes populares en los tratados médicos franceses al descrédito de la condición femenina

In ancient France, all remedies with proven efficacy were granted the status of <em>bonne fame. Médicine usuelle</em> made use of these remedies from the second half of the nineteenth century to well into the twentieth century, and at the same time spread the image of the <em>bonne femme</em> as an extremely wise old woman. However, the term was gradually distorted, taking on a pejorative meaning that would end up discrediting the women who were the bearers of this traditional knowledge. From an analysis of the French medical treatises and literature, we aim to show how the <em>bonne femme</em> came to be seen as a busybody, a quack, and in the final instance, a witch who, through her gossip, denigrated the image of other women. Hence, the knowledge that initially fell within the realms of science and medicine eventually became bound up with magic and superstition, as the status of women was gradually devalued.<br><br>En francés antiguo, todo remedio que probara su eficacia, se le otorgaba la designación de <em>bonne fame</em>. La denominada <em>médicine usuelle</em> hizo uso de ellos, desde la segunda mitad del XIX, hasta bien entrado el siglo XX, difundiendo la imagen de la <em>bonne femme</em> como una mujer ya anciana, pero colmada de sabiduría. Sin embargo, el término fue desvirtuándose progresivamente, adquiriendo un sentido peyorativo que igualmente terminaría por desacreditar a aquellas mujeres que eran portadoras de los saberes tradicionales. A través del análisis de los tratados médicos y literarios franceses, se pretende demostrar cómo la <em>bonne femme</em> se convertía entonces en una entrometida, una charlatana y, en última instancia, en una bruja que con su palabrería denigraba la imagen de otras mujeres. Los saberes que en un principio eran propios del mundo de la ciencia y la medicina, terminarían vinculándose al mundo de la magia y la superstición, en función de la gradual devaluación de la condición femenina

Carta de José Martínez Ruiz a Pedro Dorado Montero

Carta de D. José Martínez Ruiz, a D. Pedro Dorado Montero, informándole de su deseo de examinarse en Salamanca de las dos asignaturas que le quedan para terminar la carrera, critica el sistema de exámenes y evaluación en la educación española

Recherche de criteres petrographiques de la notion de flysch

Abstract From detailed study of lithologic sequences in numerous sections in the French Alps and Pyrenees (and the Romanian Carpathians), it appears that a diagnostic petrographic criterion of the flysch facies is the appearance, in a shallow pelagic milieu, of recurrent zones of anisometric sandstones (marine sandstones with elements entirely lacking in mechanical preparation, of very dissimilar size). These zones, never developed in regular cycles, seem to be related to some factor which appeared and disappeared abruptly, interrupting the pelagic sedimentation for a time.</jats:p

Communication model using Data distribution service and communication security assessment

Diplomová práca sa zameriava na problematiku middleware vrstvy v distribuovaných systémoch. Uvádza typicky používané komunikačné protokoly a štandardy, ktoré na tejto vrstve pracujú. Jej užšie zameranie je z hľadiska teoretickej aj praktickej časti na špecifikáciu OMG DDS. Priblížené sú jej základné funkcionality a architektúra spolu s jednotlivými prvkami. V práci je taktiež popísaný RTPS protokol. Na záver teoretickej časti sú popísané existujúce implementácie štandardu OMG DDS. V praktickej časti je využitá OpenDDS 3.13 implementácia tejto špecifikácie. Otestované je jej nasadenie na rôznych platformách. V ďalšej časti je overená vlastnosť zabezpečenia prenosu dát pomocou beta verzie OMG DDS Security, ktorú táto implementácia obsahuje. Porovnaný je zabezpečený a nezabezpečený prenos. V distribuovaných systémoch je dôležité aj oneskorenie prenosu systému. Pre analýzu rôznych vplyvov na výsledné oneskorenie prenosu je v praktickej časti vytvorený DDS systém, ktorý meria oneskorenie pri rôznych nastaveniach QoS a zabezpečení. Prevedené a analyzované sú merania pri rôznych vlastnostiach prenosu. Z výsledkov meraní sú zrejme vplyvy výkonu zariadenia pri zvyšovaní veľkosti odosielaných vzoriek. Zaznamené sú rozdiely oneskorenia medzi spoľahlivým a nespoľahlivým a zabezpečeným a nezabezpečeným prenosom. Uskutočnené sú aj merania medzi 2 fyzickými zariadeniami s útočníkom a bez neho. Útok je typu MITM a zachytáva RTPS prenos ktorý mu nie je určený.The diploma thesis is focusing on middleware layer in distributed systems. It introduces typically used communication protocols and standards operating on this layer. In theoretical part it brings closer look at OMG DDS specification. This part contains fundamental functionalities of this specification along with its architecture blocks. Thesis also describes the RTPS protocol functionality. Existing implementations of OMG DDS standard are described at the end of theoretical part. OpenDDS 3.13 implementation is used in practical part of thesis. It is deployed and tested on various platforms. Next part verifies option of securing RTPS data stream using beta version of OMG DDS Security, which OpenDDS 3.13 implementation contains. Secured and unsecured data flows are being compared. Latency of data stream is also important, especially in distributed systems. DDS system, which measures latency of RTPS stream is created in practical part. Latency of this DDS system can be measured in various configurations. Difference of devices’ performance used in measurements can be clearly seen in latency results where the size of data samples is increasing. Differences of measured latency are also recognizable between reliable and unreliable and secure and unsecure RTPS stream. Part of measurements is made between 2 physical devices with and without an attacker. Type of attack is MITM and it captures RTPS flow, which does not belong to attacking machine.