Thesis compares Czech railway passenger transport with Swiss railway transport for the purpose of more effective use of railway transport in domestic and incoming tourism of the Czech Republic. According to chosen standards are analysed Czech Railways and Swiss Railways with respect to quality and variety of provided services, prices, ways of ticket sales, trains and promotion. Research shows how Czech tourists use services of Czech Railways and how they like them.

Orientador: Marcio Ajudarte Lopes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-28T00:44:23Z (GMT). No. of bitstreams: 1 LucenaMarkman_Renata_M.pdf: 960885 bytes, checksum: 639bd2b482bba1e49ed3111595f8f4da (MD5) Previous issue date: 2015 / Resumo: Estudos sugerem que o tratamento radioterápico em região de cabeça e pescoço possa ser considerado um importante fator desencadeador da formação de calcificações em carótida. No entanto, evidências científicas para tal comprovação são limitadas. Portanto, os objetivos deste estudo foram identificar através de radiografias panorâmicas a prevalência de ateromas calcificados da carótida numa população com câncer de cabeça e pescoço antes e depois de serem submetidos à radioterapia e correlacionar com os aspectos sócio-demográficos e comorbidades destes pacientes. Foram selecionados, de forma retrospectiva, 180 pacientes tratados por radioterapia que tinham radiografias panorâmicas realizadas antes e após o término deste tratamento. Os dados clínicos foram coletados dos prontuários médicos. A análise das radiografias panorâmicas mostrou que 35% dos pacientes apresentaram ateromas calcificados da carótida. Não foi encontrada diferença significativa na prevalência de ateromas antes e após a radioterapia. Com relação aos achados clínicos, houve maior prevalência de acidentes vasculares cerebrais em pacientes com ateromas quando comparados aos pacientes que não apresentaram ateromas (p<0,05). Não foram observadas outras diferenças significativas com relação à idade, gênero, hipertensão arterial, diabetes mellitus, infarto agudo do miocárdio, localização do tumor e dose de radiação recebida. Sendo assim, podemos concluir que apesar da radioterapia não ter modificado a prevalência de ateromas calcificados da carótida nesta população estudada, esta alteração é frequentemente encontrada em pacientes com câncer de cabeça e pescoço. Portanto, é importante que os cirurgiões-dentistas fiquem atentos quanto à presença de ateromas em radiografias panorâmicas de pacientes com câncer de cabeça e pescoço / Abstract: Studies suggest that radiotherapy to the head and neck may be an important triggering factor for calcified carotid artery atheromas. However, scientific evidences to prove this matter are limited. Therefore, this essay aimed to identify the prevalence of calcified carotid artery atheromas observed by panoramic radiograph in a head and neck cancer population before and after radiotherapy and to correlate them with the sociodemographic features and comorbidities of these patients. For this research, 180 patients submitted to radiotherapy that had panoramic radiographs before and after this treatment, were selected retrospectively. Clinical data from these patients were collected from their medical records. The panoramic radiographs were examined and 35% of the patients demonstrated calcified carotid artery atheromas. There was no significant difference in the prevalence of atheromas before and after radiotherapy. According to clinical data, there was a greater prevalence of strokes in patients with calcified carotid artery atheromas when compared to patients who did not have atheromas (p<0.05). Differences related to age, gender, arterial hypertension, diabetes mellitus, acute myocardial infarctation, tumor location and radiotherapy dose were not observed. Thus, we can conclude that although radiotherapy did not alter the prevalence of calcified carotid artery atheromas in the studied population, this alteration is commonly found in head and neck cancer patients. Therefore, it is important that dentists be aware to the presence of calcified carotid artery atheromas in panoramic radiographs of head and neck cancer patients / Mestrado / Estomatopatologia / Mestra em Estomatopatologia

This thesis deals with the making of virtual tours in the virtual reality. It deals with panoramic photographs and their use in creating virtual tours. In this thesis, two applications were designed and implemented. The first one as a web editor for creating and the other as a mobile application for viewing virtual tours. The created solution provides a comprehensive tool for working with virtual tours.

As unmanned air vehicle (UAV) utilization increases in Wilderness Search and Rescue (WiSAR) efforts, onboard sensors yielding more information will be desired. UAVs can assist WiSAR efforts by accelerating the ground search process through returning quality aerial footage of the terrain. Additionally, tracking the progress of a search by populating a digital map with video resolution data increases confidence that a comprehensive search of the region has been made. This thesis presents methods for acquiring video from multiple video sensors and fusing them into a single rendered video stream as a Virtual Gimbal. The panoramic video stream is the first of its kind to be constructed from video transmissions from a small UAV, and the first known video panorama to be used to quickly survey a region within a WiSAR context. The Virtual Gimbal comprises two video transmissions from a three camera array mounted in a downward-looking configuration on a UAV. This video stream has been shown to decrease the amount of time required to thoroughly survey a region by more than 40 percent.

Panoramic virtual reality is an emerging technology that has recently gained the attention of both the research community and regular consumers. It allows the users to immerse themselves in omnidirectional videos with the help of a virtual reality headset : thanks to an increasing amount of affordable head-mounted-displays, any recent smartphone can offer a decent panoramic virtual reality experience. However since omnidirectional videos are videos with a large field-of-view that covers the entire sphere around the camera, they require large resolutions and thus high bitrates. This master degree project conducted at RE’FLEKT GmbH is an exploratory work that seeks to reduce the panoramic video bitrate. Because of the nature of omnidirectional videos, the user can only see a subpart of each video frame, and thus some zones of the video can attract more attention than others. The purpose of this study is to introduce the concept of region-of-interest encoding in panoramic VR. The main contribution is a method to encode panoramic videos in an H.264 video format stream with a space-variant level of details depending on the zones that attract the most the viewers’ interest. First, the region-of-interest are detected through a head-tracking module combined with a Gaussian attention model. Then, the reference video is encoded with the open source x264 encoder, with a quantization step adjusted to the region-of-interest information. The International Telecommunications Union standard subjective tests show that this method can perform better than classic H.264 encoding only in specific cases. / Panoramisk virtuell verklighet (VR) är en kommande teknik som nyligen har mött intresse från forskarsamhället och vanliga konsumenter. Det gör det möjligt för användarna att fördjupa sig i videor upptagna från flera riktningar, med hjälp av ett VR-headset : tack vare ett växande antal billiga och huvudburna bildskärmar, erbjuder alla nya smarttelefoner en passande panoramisk VR-erfarenhet. Men på grund av den breda synvinkeln i flerriktade media behöver videor med 360 graders synfält stor upplösning och därför höga bithastigheter. Detta masterexamensarbete som utförts på RE’FLEKT GmbH är ett utforskande arbete som strävar efter att reducera panoramabildens bithastighet. I flerriktade videoklipp kan användaren bara se en del av varje bildruta, härigenom får somliga zoner mer uppmärksamhet än andra. Syftet med denna studie är att introducera begreppet region-av-intresse (ROI) kodning i panoramisk VR. Huvudbidraget är en metod för att koda panoramisk video i en H.264-ström med en varierande nivå av detaljer som beror på de zoner som får mest av tittarnas intresse. Först detekteras ROI genom en huvudspårningsmodul kombinerad med en gaussisk uppmärksamhetsmodell. Därefter kodas referensvideoen med x264-kodaren (öppen källkod) med hjälp av ROI-informationen. ITU-standardens subjektiva test visar att den här metoden kan fungera bättre än klassisk H.264-kodning i enskilda fall.

El estudio tuvo como objetivo determinar la prevalencia del fallo primario de la erupción dental en radiografías panorámicas de un centro imagenológico, Chiclayo, 2023. Este estudio fue descriptivo, retrospectivo, observacional y transversal. Se analizaron las radiografías panorámicas de 220 pacientes de 11 a 15 años de edad, de ambos sexos, que presentaban al menos una primera molar permanente, que corresponden al año 2022. Según sexo 125 radiografías fueron de sexo masculino y 95 de sexo femenino. Se obtuvo, una prevalencia total de fallo primario de erupción de 0.91%, de los cuales 0,45% corresponde a cada sexo. Respecto a edad se encontró mayor predominancia en la edad de 14 años con un porcentaje del 1%, finalmente en la prevalencia según pieza dentaria se observó mayor incidencia de la pieza dentaria 85 en el 50% del total. Se concluyó que la prevalencia del fallo primario de la erupción dental alcanzó un nivel muy bajo, similar a otros estudios previos. / The study aimed to determine the prevalence of primary failure of dental eruption in panoramic radiographs of an imaging center, Chiclayo, 2023. This study was descriptive, retrospective, observational and cross-sectional. Panoramic radiographs were analyzed in 220 patients aged 11 to 15 years, of both sexes, who had at least one permanent first molar, corresponding to the year 2022. According to sex 125 x-rays were male and 95 female. A total prevalence of primary eruption failure of 0.91% was obtained, of which 0.45% corresponds to each sex. Regarding age, we found greater predominance in the age of 14 years with a percentage of 1%, finally in the prevalence according to tooth was observed greater incidence of the 85th tooth in 50% of the total. It was concluded that the prevalence of primary failure of dental eruption reached a very low level, similar to other previous studies.

Die Zielsetzung dieser Studie war es, für digitale Panoramaschichtaufnahmen die Relation der subjektiven Bildqualität zur Exposition zu bestimmen. An Hand von Humanpräparataufnahmen konnten bei Standardwerten sowie experimentellen Variationen der Expositionsdaten weiterhin Effekte der intentionellen Unterexposition sowie der Strahlenaufhärtung auf die subjektive Bildqualität quantifiziert werden. Die Herstellung der Aufnahmen erfolgte auf einem Sirona Orthophos DS. Dabei wurden 37 Aufnahmen mit Expositionswerten von 60 kV/9 mA - 84 kV/13 mA aus dem Herstellerprogramm erzeugt und mit Hilfe einer modifizierten Steuerungssoftware zusätzliche PSA mit experimentellen Einstellungen von 60 kV/3 mA - 90 kV/11 mA hergestellt. Für die Beurteilung und Auswertung der subjektiven Bildqualität wurde eine individuelle Software (Eldoredo V2.2) entwickelt. 39 Zahnärzte und 5 MTRA beurteilten die Aufnahmen damit an einem Monitor unter standardisierten Bedingungen. Ein iterativer Beurteilungsprozess erlaubte, eine Serie von 1369 (37 x 37) PSA-Abbildungspaaren darzustellen. Für jedes Paar entschieden die Untersucher an Hand definierter Kriterien, ob eine PSA hinsichtlich der subjektiv beurteilten Bildqualität vorzuziehen oder Äquivalenz gegeben sei. Nach statistischer Aufarbeitung der Einzelentscheidungen ließ sich damit für jede Expositionsstufe ein Index der Bildqualität berechnen. Bei Expositionswerten in einem Bereich von 60 kV/9 mA - 69 kV/15 mA der Herstellersoftware und 60 kV/5 - 15 mA sowie 70 kV/5 - 15mA der experimentellen Software fanden sich dabei keine signifikanten Verteilungsunterschiede der Bildqualität. Eine intentionelle Unterexposition bei digitalen PSA-Geräten, etwa bei Kindern oder häufigen Wiederholungsaufnahmen, kann nach den vorliegenden Ergebnissen vertreten werden, ohne dass es dabei zu einer signifikanten Verschlechterung der Bildqualität kommt. Damit ist im Gegensatz dazu bei einer Strahlenaufhärtung in dem untersuchten digitalen System stets zu rechnen. Insgesamt zeigen die Ergebnisse, dass auch digitale PSA-Systeme beachtliche Reserven hinsichtlich der Dosisminimierung aufweisen können. / The aim of this study was to describe the relation of the subjective image quality of digital panoramic radiographs in relation to exposure. In addition, variations of exposure were compared to standard settings, thus evaluating the effects of intentional underexposure on the achievable image quality. A Sirona Orthophos DS unit was used to produce 37 digital panoramic images of a human skull. Exposure values ranged from 60 kV/9 mA to 84 kV/13 mA in the conventional and 60 kV/3 mA to 90 kV/11 mA in the experimental setting. Assessment and evaluation of the subjective image quality were performed with an HTML-based protocol. 39 dentists and 5 radiographic assistants had to assign their preference of an image or equality in 1,369 (37x37) image pairs. The decisions were computed to a quality index for each exposure setting. Statistical analysis demonstrated no significant differences of image quality between 60 kV/9 mA - 69 kV/15 mA in the conventional and 60 kV/5 to15 mA as well as 70 kV/5 to 15 mA in the experimental setting. Following these results, a considerable dose reduction by the means of intentional underexposure can be achieved without any loss of image quality. By reducing the absorbed doses, an increase of kV values up to 80 kV and more is also correlated with dose reduction. However, those images showed high significant loss of quality. In summary, the results demonstrate an equivalent image quality of digital panoramic images over a very wide range of exposure values. The feasible dose reduction might be of interest not only in individuals (minors, repeated images), but also in defining general principles of panoramic imaging.

Ziel der Arbeit war der direkte Vergleich verschiedener Referenzierungsmarker wie Hülsen, Kugeln, Plättchen oder Guttaperchapoints bei Aufnahmen zur präimplantologischen Planung mit dem Panoramaschichtgerät. Dazu wurde ein selbstständig weiterentwickeltes Röntgenmodell eines teilbezahnten Unterkiefers verwendet. Für jedes Markersystem wurde eine Planungs-schablone mit Markern für Implantate in Regio 46 und 47 angefertigt und mit einem digitalen Panoramaschichtgerät (Orthophos XG Plus) geröntgt. Hierbei stand der Marker in Regio 47 leicht zur Okklusionsebene gekippt. Zudem wurde vom Röntgenmodell eine DVT-Aufnahme (NewTom 9000) angefertigt und die Ergebnisse mit denen der Panoramaschichtaufnahme verglichen. Die vier Panoramaschichtaufnahmen und die DVT-Aufnahme wurden von je 10 Versuchsteilnehmern ausgewertet. Die verschiedenen Einflussfaktoren wie Messinstrument, Geschlecht, Region und abweichende Stellung der Marker wurden mit mehrfaktoriellen Varianzanalysen inklusive aller Wechselwirkungen untersucht. Die Ergebnisse zeigten einen signifikanten Einfluss der Region bei der Differenz zwischen realer und gemessener Knochenhöhe. Im Mittel war die Differenz bei Region 46 (-2.2 ± 0.4 mm) höher als bei Region 47 (-1.7 ± 0.4 mm). Die mittleren Vergrößerungsfaktoren waren bei allen Markern geringfügig niedriger (1,16–1,21) als der für das Gerät ausgewiesene Vergrößerungsfaktor von 1,25. Das verwendete Messwerkzeug oder das Geschlecht der Probanden hatten keinen signifikanten Einfluss auf das Messergebnis. Nach Kalibrierung lagen Mittelwert und Standardabweichungen insgesamt bei allen Markersystemen innerhalb des geforderten Sicherheitsabstandes von mindestens einem Millimeter zum Nervkanal. Beim Regionsvergleich zeigte die Verwendung des Markertyps Hülse in Regio 47 signifikant geringere Abweichungen bei der Berechnung des realen Knochenangebotes. Der Plättchenmarker zeigte im Mittel die geringste Differenz zwischen realer und nach Kalibrierung gemessener Knochenhöhe. Beim Vergleich der Panoramaschichtaufnahme mit der digitalen Volumentomographie zeigte sich ein signifikanter Unterschied (p<0.01). Es kam zu einer mittleren Unterschätzung des Knochenangebotes von 0,5 mm beim DVT in Regio 46 und einer mittleren Überschätzung des Knochenangebotes von 0,5 mm beim Panoramaschichtgerät in Regio 46 und 47. Der Regionseffekt war dagegen nicht signifikant (p=0.15). Die Ergebnisse zeigen, dass die Panoramaschichtaufnahme unter Verwendung einer Referenzierungsschablone für die präimplantologische Röntgendiagnostik bei Fällen ohne besondere Schwierigkeit als hinreichend genau betrachtet werden kann. Unter dem Gesichtspunkt der Strahlenhygiene sollte die digitale Volumentomo¬graphie komplexen Fällen vorbehalten werden.

Radiographic modalities are used in addition to clinical methods to gain information about the patients. In the examination of the periodontium, which is comprised of the gingiva, alveolar bone, periodontal ligament, and cementum, the radiographic examination plays an integral role for diagnosis of periodontal disease. The diagnosis periodontitis is based on a finding of alveolar bone loss. Changes of the alveolar bone can be assessed by different radiographic modalities, such as intraoral radiography (bitewing and periapical radiography) and panoramic radiography. Analysis of alveolar bone loss (alveolar bone level, detection of vertical bone defect and furcation involvement) in radiographic modalities and a systematic review could be helpful to suggest the more applicable radiographic methods for diagnosis of periodontal disease. The purpose of the present study was to examine diagnostic properties of panoramic radiography for the assessment of alveolar bone loss for the diagnosis of periodontal diseases as compare to posterior bitewing radiography. For 96 patients panoramic and posterior bitewing radiographs were performed and results of analysis of visibility of radiographic images and assessment of alveolar bone loss were compared. Also, the systematic review on diagnostic properties of panoramic radiography in the assessment of alveolar bone loss was performed. Based on the results of this study, recommendations for clinical practice and for research were proposed. / Rentgeniniai tyrimo metodai taikomi, kad būtų papildyti klinikinio tyrimo duomenys. Tiriant periodontą, kurį sudaro dantenos, dantinė atauga, periodonto raiščiai ir cementas, rentgeninis tyrimas svarbus diagnozuojant periodonto ligas, nes jo metu nustatomi dantinės ataugos pokyčiai. Dantinės ataugos pokyčiams vertinti daromos rentgeno nuotraukos taikant vidinių burnos rentgeno nuotraukų darymo metodus, t. y. kandimo ar dantų šaknų rentgeno nuotraukų darymo metodus, ir išorinės burnos rentgeno nuotraukos darymo metodą, t. y. panoraminės rentgeno nuotraukos darymo metodą. Atlikus dantinės ataugos pokyčių (kaulo lygio arba rezorbcijos, kaulo defekto ir tarpšaknio kaulo pažeidimų) analizę, taikant rentgeninius metodus, ir padarius sisteminę literatūros apžvalgą, galima būtų pasiūlyti tinkamiausią rentgeno metodą periodonto ligoms diagnozuoti. Šio darbo tikslas – ištirti ir palyginti panoraminės rentgeno nuotraukos ir kaplių bei krūminių dantų rentgeno nuotraukų darymo metodų diagnostikos ypatybes vertinant dantinės ataugos pokyčius periodonto ligoms diagnozuoti. Kiekvienam, iš 96 pacientų įtrauktų į tyrimą, buvo padaryta panoraminė rentgeno nuotrauka ir kaplių bei krūminių dantų kandimo rentgeno nuotraukos. Atlikta dantinės ataugos rentgeno atvaizdo vizualioji kokybė analizė ir vertinimai skirtingose rentgeno nuotraukose bei palyginti rezultatai. Padaryta sisteminė literatūros apžvalga apie panoraminės rentgeno nuotraukos vertę diagnozuojant periodonto ligas. Pagal šio tyrimo... [toliau žr. visą tekstą]

Rentgeniniai tyrimo metodai taikomi, kad būtų papildyti klinikinio tyrimo duomenys. Tiriant periodontą, kurį sudaro dantenos, dantinė atauga, periodonto raiščiai ir cementas, rentgeninis tyrimas svarbus diagnozuojant periodonto ligas, nes jo metu nustatomi dantinės ataugos pokyčiai. Dantinės ataugos pokyčiams vertinti daromos rentgeno nuotraukos taikant vidinių burnos rentgeno nuotraukų darymo metodus, t. y. kandimo ar dantų šaknų rentgeno nuotraukų darymo metodus, ir išorinės burnos rentgeno nuotraukos darymo metodą, t. y. panoraminės rentgeno nuotraukos darymo metodą. Atlikus dantinės ataugos pokyčių (kaulo lygio arba rezorbcijos, kaulo defekto ir tarpšaknio kaulo pažeidimų) analizę, taikant rentgeninius metodus, ir padarius sisteminę literatūros apžvalgą, galima būtų pasiūlyti tinkamiausią rentgeno metodą periodonto ligoms diagnozuoti. Šio darbo tikslas – ištirti ir palyginti panoraminės rentgeno nuotraukos ir kaplių bei krūminių dantų rentgeno nuotraukų darymo metodų diagnostikos ypatybes vertinant dantinės ataugos pokyčius periodonto ligoms diagnozuoti. Kiekvienam, iš 96 pacientų įtrauktų į tyrimą, buvo padaryta panoraminė rentgeno nuotrauka ir kaplių bei krūminių dantų kandimo rentgeno nuotraukos. Atlikta dantinės ataugos rentgeno atvaizdo vizualioji kokybė analizė ir vertinimai skirtingose rentgeno nuotraukose bei palyginti rezultatai. Padaryta sisteminė literatūros apžvalga apie panoraminės rentgeno nuotraukos vertę diagnozuojant periodonto ligas. Pagal šio tyrimo... [toliau žr. visą tekstą] / Radiographic modalities are used in addition to clinical methods to gain information about the patients. In the examination of the periodontium, which is comprised of the gingiva, alveolar bone, periodontal ligament, and cementum, the radiographic examination plays an integral role for diagnosis of periodontal disease. The diagnosis periodontitis is based on a finding of alveolar bone loss. Changes of the alveolar bone can be assessed by different radiographic modalities, such as intraoral radiography (bitewing and periapical radiography) and panoramic radiography. Analysis of alveolar bone loss (alveolar bone level, detection of vertical bone defect and furcation involvement) in radiographic modalities and a systematic review could be helpful to suggest the more applicable radiographic methods for diagnosis of periodontal disease. The purpose of the present study was to examine diagnostic properties of panoramic radiography for the assessment of alveolar bone loss for the diagnosis of periodontal diseases as compare to posterior bitewing radiography. For 96 patients panoramic and posterior bitewing radiographs were performed and results of analysis of visibility of radiographic images and assessment of alveolar bone loss were compared. Also, the systematic review on diagnostic properties of panoramic radiography in the assessment of alveolar bone loss was performed. Based on the results of this study, recommendations for clinical practice and for research were proposed.