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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Communication and Networking Techniques for Traffic Safety Systems

Chisalita, Ioan January 2006 (has links)
<p>Accident statistics indicate that every year a significant number of casualties and extensive property losses occur due to traffic accidents. Consequently, efforts are directed towards developing passive and active safety systems that help reduce the severity of crashes, or prevent vehicles from colliding with one another. To develop these systems, technologies such as sensor systems, computer vision and vehicular communication have been proposed. Safety vehicular communication is defined as the exchange of data between vehicles with the goal of providing in-vehicle safety systems with enough information to permit detection of traffic dangers. Inter-vehicle communication is a key safety technology, especially as a complement to other technologies such as radar, as the information it provides cannot be gathered in any other way. However, due to the specifics of the traffic environment, the design of efficient safety communication systems poses a series of major technical challenges.</p><p>In this thesis we focus on the design and development of a safety communication system that provides support for active safety systems such as collision warning and collision avoidance. We begin by providing a method for designing the support system for active safety systems. Within our study, we investigate different safety aspects of traffic situations. For performing traffic investigations, we have developed ECAM, a temporal reasoning system for modeling and analyzing accident scenarios.</p><p>Next, we focus on the communication system design. We investigate approaches that can be applied to implement safety vehicular communication, as well as design aspects of such systems, including networking techniques and transmission procedures. We then propose a new solution for vehicular communication in the form of a distributed communication protocol that allows the vehicles to organize themselves in virtual clusters according to their common interest in traffic safety. To disseminate the information used for organizing the network and for assessing dangers in traffic, we develop an anonymous context-based broadcast protocol. This protocol requires the receivers to determine whether they are the intended destination for sent messages based on knowledge about their current situation in traffic. This communication system is then augmented with a reactive operation mode, where warnings can be issued and forwarded by vehicles. A vehicular communication platform that provides an implementation framework for the communication system, and integrates it within a vehicle, is also proposed. Experiments have been conducted, under various conditions, to test communication performance and the system’s ability to reduce accidents. The results indicate that that the proposed communication system can efficiently provide the exchange of safety information between vehicles.</p>
2

Communication and Networking Techniques for Traffic Safety Systems

Chisalita, Ioan January 2006 (has links)
Accident statistics indicate that every year a significant number of casualties and extensive property losses occur due to traffic accidents. Consequently, efforts are directed towards developing passive and active safety systems that help reduce the severity of crashes, or prevent vehicles from colliding with one another. To develop these systems, technologies such as sensor systems, computer vision and vehicular communication have been proposed. Safety vehicular communication is defined as the exchange of data between vehicles with the goal of providing in-vehicle safety systems with enough information to permit detection of traffic dangers. Inter-vehicle communication is a key safety technology, especially as a complement to other technologies such as radar, as the information it provides cannot be gathered in any other way. However, due to the specifics of the traffic environment, the design of efficient safety communication systems poses a series of major technical challenges. In this thesis we focus on the design and development of a safety communication system that provides support for active safety systems such as collision warning and collision avoidance. We begin by providing a method for designing the support system for active safety systems. Within our study, we investigate different safety aspects of traffic situations. For performing traffic investigations, we have developed ECAM, a temporal reasoning system for modeling and analyzing accident scenarios. Next, we focus on the communication system design. We investigate approaches that can be applied to implement safety vehicular communication, as well as design aspects of such systems, including networking techniques and transmission procedures. We then propose a new solution for vehicular communication in the form of a distributed communication protocol that allows the vehicles to organize themselves in virtual clusters according to their common interest in traffic safety. To disseminate the information used for organizing the network and for assessing dangers in traffic, we develop an anonymous context-based broadcast protocol. This protocol requires the receivers to determine whether they are the intended destination for sent messages based on knowledge about their current situation in traffic. This communication system is then augmented with a reactive operation mode, where warnings can be issued and forwarded by vehicles. A vehicular communication platform that provides an implementation framework for the communication system, and integrates it within a vehicle, is also proposed. Experiments have been conducted, under various conditions, to test communication performance and the system’s ability to reduce accidents. The results indicate that that the proposed communication system can efficiently provide the exchange of safety information between vehicles.
3

Towards Safer Rides: Measuring Motorcycle Dynamics with Smartphones

Stanglmayr, Maximilian, Bäumler, Maximilian 26 October 2020 (has links)
Motorradfahrer gehören zu den am meisten gefährdeten Verkehrsteilnehmern im Straßenverkehr. Häufig ist die Unfallursache ein Kontrollverlust auf Landstraßen, der durch Ausnutzung des physikalischen Potenzials in Form von größeren Schräglagenwinkeln vermieden werden könnte. Gleichzeitig sind in der Realität gefahrene Schräglagen über eine größere Gruppe von Fahrern und eine längere Strecke unbekannt, was vor allem auf die erforderliche spezielle Messtechnik zurückzuführen ist. Der Schwerpunkt liegt daher auf der Entwicklung eines kostengünstigen Messverfahrens zur Messung der Schräglagenwinkel von Motorrädern. Smartphones zeichnen sich in der Regel durch integrierte Inertialsensoren aus, die für die Erfassung der Fahrdynamik von Motorrädern geeignet sind. Mit Hilfe einer auf die Anforderungen zugeschnittenen Smartphone-App zur Erfassung von Messdaten auf dem Motorrad werden die Daten der Sensoren aufgezeichnet. Anschließend werden mittels einer Offline-Auswertung die Drehwinkel zwischen dem Smartphone und dem Motorrad-Koordinatensystem bestimmt, die inertialen Messdaten transformiert und der Schräglagenwinkel berechnet. Ein wesentlicher Bestandteil ist die Validierung der entwickelten Messkette durch einen Vergleich der Ergebnisse mit einem hochpräzisen Messsystem. Dieser wurde auf verschiedenen Strecken zur Bestimmung der Datenqualität durchgeführt. Als Machbarkeitsstudie diente eine Probandenstudie, die die Praxistauglichkeit der Messkette bestätigte. Die Studienergebnisse werden zusätzlich auszugsweise dargestellt und diskutiert. Die erfolgreiche Validierung auf verschiedenen Strecken, die Praxistauglichkeit der Datenerfassung und die Genauigkeit des Messsystems ermutigen dazu, die Smartphone-App auf ein größeres Panel von Testpersonen auszurollen und damit Daten über ein größeres Fahrerkollektiv zu erheben.:Introduction, State of Research, Methods, Measurement Chain Verification, Results and Discussion, Conclusion / Motorcyclists are among the most vulnerable road users in road traffic. Often, the cause of accidents is a loss of control on rural roads which could be averted by making use of the physical potential in terms of larger lean angles. At the same time, in reality driven lean angles over a larger group of riders and a longer route are unknown which is mainly due to the special measuring technology required. The focus is therefore on the development of a low-cost measurement method for measuring the lean angles of motorcycles. Smartphones are usually characterized by integrated inertial sensors, which are suitable for the acquisition of motorcycle driving dynamics. Employing a smartphone app tailored to the requirements for collecting measurement data on the motorcycle, the data of the sensors are recorded. During the offline evaluation, the rotation angles between the smartphone and the motorcycle coordinate system are determined, the inertial measurement data are transformed and the roll angle is calculated. An essential part is the alignment of the developed measurement chain with a high-precision measurement system. This was carried out on different routes and thus the data quality was determined. As a feasibility study, a test person study with several participants was carried out, which confirmed the practical suitability of the measurement chain. Hence, the study outcomes are briefly shown and discussed. The successful validation on different routes, the practical suitability of the data acquisition and the accuracy of the measurement system encourage to roll out the smartphone app to a larger panel of test persons and thus to collect data on a larger driver collective.:Introduction, State of Research, Methods, Measurement Chain Verification, Results and Discussion, Conclusion
4

Use of ClinicalTrials.gov Registry in Systematic Reviews and Meta-analyses: A Master's Thesis

Pradhan, Richeek 30 November 2017 (has links)
Ensuring the objectivity of systematic reviews and meta-analyses (SRMA) begins with comprehensive searches into diverse resources mining primary studies. Guidelines for systematic reviews recommend authors to routinely search of trial registries to identify unpublished studies. In this dissertation, I investigated the utilization of ClinicalTrials.gov (CTG), the world’s largest clinical trial registry that contains data from clinical trials of products that are subject to United States Food and Drug Administration (FDA) regulation, as an information resource in SRMAs. First, I examined the use of various information resources including CTG in SRMAs published from 2005-2016, and identified the factors associated with their use. Thereafter, to determine the accuracy of trial safety data reported at CTG, I compared the data at CTG with that in corresponding journal articles and FDA drug reviews. I found that trial safety data at both CTG and articles differed frequently from FDA drug reviews, but the differences were modest in magnitude. Finally, I repeated published meta-analysis (conducted using data from primary study articles) with data at CTG to find that most meta-analysis results were reproduced using CTG data. Taken together, this work suggests that CTG should not only be searched more often to find primary research for systematic reviews, but that data at CTG can also be used to conduct quantitative data synthesis.
5

Literacy and Hazard Communication Comprehension of Employees Presenting to an Occupational Health Clinic

Bouchard, Christine 01 January 2011 (has links)
More than 100 million American workers, 7 million workplaces, and 945,000 hazardous chemical products are covered under the Hazard Communication Standard (HCS), regulated by the Occupational Safety and Health Administration. There were a total of 1,183,500 recordable non-fatal illnesses and injuries in private industry workplaces in 2006 resulting in days away from work. Of these, 19,480 were due to chemicals and chemical products. In addition, there were a total of 5,703 work-related fatalities in 2006. In 191 of these, chemicals and chemical products were listed as the primary source of injury and as the secondary source of injury in 104 cases. The economic impact of both fatal and non-fatal occupational injuries amounted to $164.7 billion in 2006. OSHA established the HCS in order to ensure that workers are informed of the hazardous chemicals with which they work, yet OSHA admits that many adults may have difficulty reading material that communicates hazards. Violations of OSHA's HCS were the third most cited violation in 2007. Since only 12 percent of the adults surveyed in the United States demonstrated Proficient health literacy, the state of affairs poses a serious problem for hazard communication, which nurses and nurse practitioners are often responsible for conveying. Health tasks that require Proficient health literacy include "drawing abstract inferences, comparing or contrasting multiple pieces of information within complex texts or documents, or applying abstract or complicated information from texts or documents". Donabedian's Structure-Process-Outcome framework served as the conceptual basis for this study. Twelve research studies (nine journal articles and three doctoral dissertations) published between 1993 and 2003 were reviewed. None of these studies measured the participants' literacy level. The purpose of this single administration, cross-sectional study was to examine literacy levels as a hypothesized predictor of test scores of employees presenting to the Lakeside Occupational Medical Center, Downtown Clinic, for a physical examination, immunization, drug screening, or follow-up appointment. MSDS test scores served as the dependent variable and were measured by an investigator-made test consisting of seven passages, taken from seven separate MSDSs for sodium hypochlorite, each from a different manufacturer. Sodium hypochlorite is commonly utilized in numerous industries including the janitorial, pulp, paper, textile, dairy, and water-cooling industries and is known to cause work-related health effects such as asthma and irritation of the eyes and throat. Each passage was followed by five multiple choice questions. Literacy levels were measured utilizing the Short Test of Functional Health Literacy in Adults (STOFHLA). The readability level of the written material was measured utilizing the Simplified Measure of Gobbledygook (SMOG) and the Flesch-Kincaid Grade Level (FKGL). The characteristics of age, highest grade level completed, native language, and job category were measured by a demographic sheet. The results indicate that there was a significant positive correlation between the total STOFHLA scores and the total scores on the MSDS test. Therefore, hypothesis number 1 was supported. Findings on the readability level of the examples of the MSDSs to the participant's overall MSDS score were inconclusive. However, the format of the MSDS, specifically the number of lines/sentence and the number of words that are 3 syllables or more, may influence comprehension. Therefore, written hazard communication material should be written in short sentences and use words less than 3 syllables. This way the likelihood of the material being understood by the worker will be increased. Further research aimed at understanding exactly how reading grade level and sentence structure impacts comprehension of hazardous materials information is needed.
6

Zvýšení úrovně spolehlivosti dodávky elektrické energie z hydrocentrály Jasenie do Železiarní Podbrezová / Increasing of reliability of power supply from the Jasenie hydropower plant to Železiarně Podbrezová

Budovec, Michal January 2019 (has links)
This thesis deals with operation of the Jasenie hydroelectric power plant, which supplies electricity to Železiarne Podbrezová Inc. This thesis describes actual operation, devices and equipment in all substations. The second chapter briefly describes company’s history and activities of the company. The next chapter mentions an overview of the sources of own electricity production. The fourth chapter in detail deals with actual situation of the hydroelectric power plant operation, describes devices and equipment in all substations. It also outlines what measures should be taken to increase the reliability of electricity supply. Next part deals with replacing insulators on the 22 kV line. Sixth chapter is focused on protection this line by multifunctional protection relay and data transfer from HC Jasenie to the building of power engineering. In the next step is designed a backup transformer with bus control for thermal and dynamic effects of the short-circuit current. The last chapter is focused on surge protection in HC Jasenie as well as in the area of Stary závod substation. The results and benefits of this work are summarized in the conclusion. The attachment contains schemes of substations and overall overview scheme, which are used for better understanding of this problem.
7

A multidisciplinary risk assessment of dental restorative materials.

Tillberg, Anders January 2008 (has links)
Amalgam has been used as a dental restorative material for centuries, but its potential health effects and biopersistance has lead to a decreased use especially in the Nordic countries. New materials have been introduced, partly to replace the mercury containing amalgam and partly because of esthetical reasons. The possible health effects of amalgam have been studied extensively and the material has been replaced with other less well-examined materials during the last few decades. The prevalence of side effects of dental materials is considered to be low in relation to the vast number of dental treatments undertaken. With the introduction of new and more complex materials, side effects related to dental treatment may increase. Epidemiological data suggest that the side effects of dental resins that have almost completely replaced amalgam fillings in Scandinavia, possess a risk for adverse reactions; however, the causal relation has not been fully established. Therefore, the type and extent of side effects caused by resin-based materials are of great interest. The aims of the study were: - to describe the change in health over time for patients with problems related to their dental materials. The hypothesis was that the patients could be divided into subgroups based on their symptoms and that the ability to recover differs between these groups [Paper I]. Furthermore, to determine whether factors such as the replacement of dental restorative materials and follow-up time had any impact on the perceived health. - to assess the long-term development of symptoms and their social consequences among patients referred for diagnosis and treatment of symptoms related to dental materials [Paper II] - to investigate the possible risks with dental restorative materials other than amalgam [Paper III]. - to describe side effects assessed to be caused by resin-based materials that occurred in a group of patients as well as treatment and long-term consequences of the reactions [Paper IV]. A questionnaire was sent to 614 patients [Paper I and II] that had been referred to the School of Dentistry, Umeå, Sweden, with symptoms allegedly caused by dental materials. The questionnaire contained questions on, among others; civil status, present health, medical and dental treatment and other measures and precautions taken because of psychosocial problems related to current employment situation, feelings, self-image and coping behavior. Moreover, information was collected [Paper III] from the Swedish Dental Materials Register 2003 (DentMr), a compilation of MSDS for 487 materials, and information from the user guide of the materials. The Material Safety Data Sheets (MSDS) included in the DentMR were examined regarding the given composition of the products, the occurrence of CAS-numbers and the risk- and safety phrases of the substances. Information was collected [Paper IV] on 36 patients with reactions to resin-based restorative materials from the Swedish National Register of Side-Effects of Dental Materials. Patients with complex symptoms had a more unfavorable long-term prognosis concerning persistent complaints than those with local symptoms only. Furthermore, the results indicate that the patients might experience health improvements after removal of their dental restorative materials. However, the reason for this improvement was unclear. Replacement of dental restorative materials had no significant impact on the ability to recover completely. Our results also indicate a relationship between patients’ self-related health and social consequences in daily life. Those with remaining complex symptoms had more often stopped working or had decreased their work hours because of their symptoms The information about hazards with dental materials seems insufficiently described in MSDS and there might be materials with side effects unknown to both patients and dental professionals. A literature search indicated that some of the listed substances had possible hazards, e.g. substances with embryotoxic and neurotoxic potential. The patients were very heterogeneous; a few with only local symptom free reactions while other had more complex symptoms. The latter group would gain from a multidisciplinary approach, i.e. dental, medical, as well as social and psychological factors have to be considered when developing care management programs for this group of patients. Furthermore, there is a need for stronger regulations of dental materials, such as those applied to pharmaceutical drugs. Finally, it was found that the majority of symptoms suspected to be caused by resin-based materials were local or a combination of local and extra-oral symptoms that appeared within the first 24 hours after treatment. The most frequent adverse effect reported was skin problems/dermatitis. It appears as though immediate reactions to resin based materials are not uncommon and more prevalent than allergic reactions. Still, we have had, difficulties in verifying associations between the dental restorative materials and adverse reactions and also to identify the offending component.
8

Förenklad riskbedömning av byggvaruprodukter innehållande kemiska ämnen : För anställdas hälsa på kommunalägda Bostads AB Mimer

Svensson, Sandra January 2015 (has links)
This bachelor thesis is about chemical products from the construction industry which are being used by the company Bostads AB Mimer (Mimer), owned by the municipality Västerås in Sweden. The company owns apartments and houses around the city. The aim of this bachelor thesis is to do a simplified risk assessment of the chemical products from a health and  environmental point. The report also gives suggestions of substitutional products. The thesis work consists of a literature study, an analysis of how other companies within the housing sector are working with chemical products and a case study, in addition to the simplified risk assessment. The case study contains a selection of Mimer's chemical products. In order to succeed with the simplified risk assessment, the chemical product’s risks and hazards has been identified through safety data sheets (SDS). Different aspects have been taken into account in the simplified risk assessment. The selection of the chemical products were made after existence frequency and legislative product labeling. The report's results gave 16 selected chemical products, that are risk assessed. Of the 16 chemical products, eight products have a high risk score from a heath point. Suggestions of less hazardous chemical products are given to nine chemical products. The essay's conclusions are that some of the selected chemical products are hazardous to the health and the environment, due to their chemical substances. The staff at Mimer's has a high frequency of use of the chemical products in general. Most of the other companies in the housing sector that  were investigated in the analysis, had a systematic work on chemicals.

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