Examensarbetet har utförts på företaget Husqvarna AB vid avdelning Concept & Features electric products (EN-NEP). Uppdraget var att utvärdera en alternativ kollisionsmetod till deras robotgräsklippare. Metoden som utvärderats går ut på att detektera kollision med hjälp av samplad data från en accelerometer samt samplad strömnivå från de bägge drivhjulens motorer. Den metod som används för att detektera kollision på nuvarande robotar fungerar väl men kräver att robotens kaross och chassi rör sig ifrån varandra för att krock skall detekteras. För att kunna reducera antalet komponenter och priset på roboten är andra metoder intressanta att utvärdera för uppdragsgivaren. En algoritm har designats i simulationsmiljö som sedan testats på ”riktigt” genom implementation i en Raspberry Pi som kommunicerar med robotgräsklipparen. Om den implementerade algoritmen detekterat krock på den samplade datan skickas ett meddelande till roboten att utföra sitt inbyggda krockmönster. Resultatet som erhölls var ett fungerande system med stor potential. Med fortsatt arbete skulle metoden kunna bli en framtida ersättare alternativt ett komplement till nuvarande metod.

Syfte: Syftet med studien var att med accelerometri undersöka hur stillasittande tid skiljer sig mellan individer med olika aktivitetsnivå på ett företag. En vidare målsättning var att undersöka sambandet mellan objektiv och subjektiv mätmetod av fysisk aktivitet och stillasittande tid. Metod: Totalt 86 personer fullföljde sin medverkan, av dessa var 72 kvinnor och 14 män. De fick dels besvara ett frågeformulär om fysisk aktivitet och stillasittande, samt bära en accelerometer under 7 dagar i följd. Frågeformuläret bestod av delar av och hela redan befintliga frågeformulär: den korta versionen av IPAQ, Socialstyrelsen och GIH:s hälsoenkät. Deltagarna delades in i två grupper efter aktivitetsnivå enligt accelerometrimätningen, de som uppnådde rekommendationen för fysisk aktivitet och de som inte gjorde det. Stillasittande tid jämfördes sedan mellan dessa två grupper. Vidare undersöktes samband mellan rapporterad data från frågeformulären och resultat från accelerometrimätningen för samtliga deltagare.  Resultat: Den grupp som nådde upp till rekommendationen hade medianvärdet 10,9 timmar (IQR = 1) totalt stillasittande per dag och den grupp som inte nådde upp till rekommendationen för fysisk aktivitet hade medianvärdet 11,2 timmar (IQR = 2). Ingen signifikant skillnad mellan gruppernas totala tid i stillasittande framkom.   Högst signifikant samband (*), mellan accelerometridata och enkätfrågor, sågs för uppmätt fysisk aktivitet med hög intensitet både för formulären från Socialstyrelsen och IPAQ (r=0,46*-0,48*), för både öppna frågor och de med fasta svarsalternativ. För minst måttligt intensiv fysisk aktivitet var motsvarande samband högst för en av GIH:s hälsoenkätfrågor (0,40*), en fråga med fasta svarsalternativ. Liknande nivå sågs för Socialstyrelsens öppna fråga (0,39*) om totalt antal aktivitetsminuter. Sambanden för stillasittande tid var lägre, där en fråga från GIHs hälsoenkät gav den starkaste signifikanta korrelationen (0,30*) som hade fasta svarsalternativ. IPAQ kort version, som är ett internationellt frågeformulär som ofta används i forskningssammanhang, visade på ett lågt icke signifikant samband mellan accelerometridata och frågan om stillasittande tid (r = 0,20).  Slutsats: Enligt denna undersökning skiljer sig inte stillasittande tid mellan individer som uppfyller rekommendationen för fysisk aktivitet gentemot dem som inte gör det. Man bör utveckla mätningar av och rekommendationer för stillasittande tid, där det är önskvärt med mer forskning inom detta område. Majoriteten av studier på stillasittande är självrapporterad data med frågeformulär, som har visat på brister enligt denna och andra studier.

Made available in DSpace on 2014-06-11T19:28:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-07Bitstream added on 2014-06-13T20:58:29Z : No. of bitstreams: 1 juliani_f_me_guara.pdf: 7467903 bytes, checksum: 5354d77ba11f440d705f38fd2fe0eaf0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A vibração é um dos fenômenos que deve ser controlado quando atinente à componentes aeroespaciais. Sua ocorrência, em geral, não é benéfica para a vida útil de um sistema mecânico desse tipo e, por isso, este deve ser submetido a inúmeros testes de vibração para que informações sobre seu comportamento em operação sejam conhecidas. Sendo o acelerômetro o principal componente do sistema de medição empregado nos testes de vibração em sistemas mecânicos, é fundamental que sua calibração seja realizada periodicamente de forma a garantir suas condições operacionais. O processo de calibração secundária de acelerômetros especificamente envolve informações determinantes para a obtenção de resultados confiáveis e análise correta do comportamento de uma estrutura submetida a um ambiente vibratório. O valor de sensibilidade para uma frequência fixa de calibração é um exemplo de informação relevante que deve ser gerenciada. O Laboratório Central de Calibração de Acelerômetros do Comando da Aeronáutica é responsável pelo controle de um elevado número desses transdutores e, portanto, deve gerenciar dados de sua calibração e utilização. No entanto, deficiências foram detectadas no modo de controle vigente. Esta pesquisa propõe uma sistemática auxiliada por sistema proprietário de banco de dados para o gerenciamento laboratorial de dados de calibração de acelerômetros utilizados em testes e monitoramentos de vibração mecânica atendendo a itens da norma NBR ISO/IEC 17025 (2005) / Vibration is one of the phenomena that must be controlled regarding aerospace components. In general, its occurrence is not beneficial to the life cycle of such a mechanical system, and therefore it must be subjected to numerous vibration tests so that information about its behavior in operation is known. Since the accelerometer is the main component of the measuring system employed in mechanical vibration tests, it is essential that its calibration is performed periodically to ensure its operational conditions. The accelerometer secondary calibration process specifically involves critical information to obtain reliable results and correct analysis of the behavior of a structure subjected to a vibration environment. The sensitivity value for a fixed frequency calibration is an example of relevant information that must be managed. The Brazilian Air Force Command Central Laboratory of Accelerometer Calibration is responsible for managing a large number of transducers and therefore must manage data from their calibration and use. However, deficiencies were detected in the current control system. This research proposes a systematic approach aided by a proprietary database to manage the laboratory calibration data of accelerometers used in testing and monitoring of mechanical vibration according to NBR ISO/IEC 17025 (2005) item.

Orientador: Mauro Hugo Mathias / Coorientador: Everaldo de Barros / Banca: José Elias Tomazini / Banca: Carlos D'Andrade Souto / Resumo: A vibração é um dos fenômenos que deve ser controlado quando atinente à componentes aeroespaciais. Sua ocorrência, em geral, não é benéfica para a vida útil de um sistema mecânico desse tipo e, por isso, este deve ser submetido a inúmeros testes de vibração para que informações sobre seu comportamento em operação sejam conhecidas. Sendo o acelerômetro o principal componente do sistema de medição empregado nos testes de vibração em sistemas mecânicos, é fundamental que sua calibração seja realizada periodicamente de forma a garantir suas condições operacionais. O processo de calibração secundária de acelerômetros especificamente envolve informações determinantes para a obtenção de resultados confiáveis e análise correta do comportamento de uma estrutura submetida a um ambiente vibratório. O valor de sensibilidade para uma frequência fixa de calibração é um exemplo de informação relevante que deve ser gerenciada. O Laboratório Central de Calibração de Acelerômetros do Comando da Aeronáutica é responsável pelo controle de um elevado número desses transdutores e, portanto, deve gerenciar dados de sua calibração e utilização. No entanto, deficiências foram detectadas no modo de controle vigente. Esta pesquisa propõe uma sistemática auxiliada por sistema proprietário de banco de dados para o gerenciamento laboratorial de dados de calibração de acelerômetros utilizados em testes e monitoramentos de vibração mecânica atendendo a itens da norma NBR ISO/IEC 17025 (2005) / Abstract:Vibration is one of the phenomena that must be controlled regarding aerospace components. In general, its occurrence is not beneficial to the life cycle of such a mechanical system, and therefore it must be subjected to numerous vibration tests so that information about its behavior in operation is known. Since the accelerometer is the main component of the measuring system employed in mechanical vibration tests, it is essential that its calibration is performed periodically to ensure its operational conditions. The accelerometer secondary calibration process specifically involves critical information to obtain reliable results and correct analysis of the behavior of a structure subjected to a vibration environment. The sensitivity value for a fixed frequency calibration is an example of relevant information that must be managed. The Brazilian Air Force Command Central Laboratory of Accelerometer Calibration is responsible for managing a large number of transducers and therefore must manage data from their calibration and use. However, deficiencies were detected in the current control system. This research proposes a systematic approach aided by a proprietary database to manage the laboratory calibration data of accelerometers used in testing and monitoring of mechanical vibration according to NBR ISO/IEC 17025 (2005) item. / Mestre

Background: Adults with Intellectual Disability (ID) experience health disparities that may be attributable to high sedentary behavior (SB). The levels and patterns of SB among U.S. adults with ID have received little attention. Purpose: To examine levels and patterns of SB in adults with ID. Method: The sample included 52 adults with ID who wore an accelerometer on the hip for 7 days. We determined total sedentary time, percent of wear time spent sedentary, number and duration of sedentary bouts, and breaks in sedentary time. We used t-tests and 2×2 ANOVA to evaluate the effects of sex or age-group and day of the week. Result: Adults with ID spent about 8-8.5 hours per day in SB and they primarily accumulated sedentary time in bouts 1-30 min in duration. Conclusion: Apart from small differences in SB, people with ID appear to have near uniform SB levels and patterns throughout the week.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Acquiring shock and vibration data from flight vehicles through rf telemetry links has numerous associated challenges. Yet, these measurements are important to establish environmental specifications to provide a basis for system or component design and testing. The principal limitation in acquiring these measurements is the frequency bandwidth available for data transmission. This limited bandwidth is often responsible for invalid data being accepted as valid. This work provides a brief review of time and frequency division multiplexing to identify the potential error contributors to shock and vibration measurements. Its focus is on the design of acceleration measurement systems to eliminate these errors and optimize individual measurement channel performance.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / For years, ballisticians have been studying the phenomena associated with cannon launched projectiles. In particular, is the study of the pressure internal to the cannon and about the base of the projectile during cannon launch through muzzle exit. Pressure on the base is thought to be uniform and therefore hydrostatic, even though there are undulations in the magnitude of the pressure from the burning propellant. This paper studies various phenomena of the launching of 155-mm artillery projectiles with slip band obturators. Specifically, pressure gradients in and around the base and pressure along the body caused by obturator “blow-by” during the interior ballistic flight and muzzle exit. This study is accomplished by use of two different types of Instrumented Ballistic Test Projectiles (IBTP). The objective of tests performed was to successfully capture pressure and acceleration live data which will be used to characterize the localized base and body pressurization on a 155-mm artillery cannon launched projectile. The telemetry system used for these tests was the ARRT-124 telemetry system provided by the Armament Research, Development, and Engineering Center, specifically the Precision Munitions Instrumentation Division. The telemetry system used for the IBTP employs a traditional FM/FM technique for monitoring and transmitting a number of analog channels. Preliminary captured data indicated localized fluctuations in pressure that are not uniform over the base and the projectile body. Further studying of the data may provide insight into other projectile dynamics such as fin deployment, set forward accelerations at muzzle exit, and obturator performance.

Background: Because it is a strong determinant of chronic disease and mortality risk, physical activity is a health behaviour that is measured in most large health surveys. Questionnaires are the most commonly used method for measuring physical activity in health surveys. In the early 1990’s, an international physical activity questionnaire (IPAQ) was created to allow researchers from across the globe to employ the same questionnaire within their country. Several studies have been conducted on the IPAQ to determine whether the responses obtained are comparable when the questionnaire is administered on multiple occasions (reliability) and to determine the ability of the questionnaire to obtain the same physical activity result when compared to other direct measures, considered as “gold standard” (validity). However, none of these studies have been conducted in Mexico. Objective: Examine: 1) the reliability of the IPAQ among Mexican adults by comparing minutes per week (min/wk) spent in moderate-to-vigorous physical activity (MVPA) from the IPAQ administered two times, 2) the validity of the IPAQ surveys by comparing IPAQ min/wk of MVPA to those obtained by the accelerometer. Methods: 267 Mexican adults who worked in a factory in Mexico City participated. IPAQ was applied in a face-to-face interview during a first clinic visit. Participants received an accelerometer (motion sensor that measures and record physical activity) and wore it consecutively for the next 9 days. In a second visit, participants returned the accelerometer and completed a second IPAQ. The research team cleaned and analyzed the accelerometer data using standardized techniques. Results from the two IPAQ and the accelerometer were compared using the appropriate statistical tests. Results: IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r=0.55, p<0.01). The MVPA (min/week) measures from IPAQ1 and IPAQ2 were only modestly correlated with the accelerometer measures (r=0.26 and r=0.31, p<0.01). The percentage of the participants who were classified as inactive according to the World Health Organization physical activity guidelines was 18.0% in IPAQ1, 25.1% in IPAQ2, and 28.2% for the accelerometer. Conclusions: IPAQ was modestly correlated to each other and it was lowly correlated to values obtained by the accelerometer. Since IPAQ has been used to obtain physical activity prevalence worldwide, caution should be taken when this instrument is used. Future research should be focused on the importance of including direct measures to measure physical activity levels within epidemiological surveys. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-04-18 15:12:21.626

Total weekly moderate-to-vigorous (MVPA) accumulated in different patterns has not been well studied: it is not yet known whether sporadic MVPA (periods of <10 consecutive minutes) or whether the weekly frequency of MVPA is associated with health benefits in adults. For this reason, the physical activity guidelines recommend that adults aged 18 to 64 years accumulate at least 150 minutes of MVPA per week in bouts of at least 10 minutes. The overall objective of this thesis was therefore to study the relationships between different patterns of MVPA and the metabolic syndrome (MetS) – a clustering of risk factors that increases the risk of developing cardiovascular disease and type 2 diabetes in adults. Both manuscripts in this thesis used data from the Canadian Health Measures Survey (CHMS), a nationally-representative sample of Canadians. The MetS was determined from direct physical measurements and blood samples, while physical activity levels were assessed by accelerometers (also known as activity monitors). Complex statistical models were used to determine the relationship between patterns of MVPA and the MetS. The first study assessed whether bouted MVPA was associated with lower odds for MetS than an equal volume of sporadic MVPA. Results showed that both bouted and sporadic MVPA were equally related to the MetS; even small bursts of sporadic MVPA <3 minutes in length were meaningful when predicting the MetS. The second study evaluated whether more frequent weekly MVPA was associated with lower odds for the MetS in physically active adults. Among those who were considered physically active, there was no difference in the odds of the MetS between those who were infrequently or frequently active. Together, the results of this thesis suggest that the pattern in which weekly MVPA is accumulated is unimportant, provided that sufficient energy is expended. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-07-10 16:01:22.091

Idag ses ett ökat intresse för användandet av rörelseanalys inom olika sammanhang t.ex. övervakning, dataspel och diagnostisk undersökning av personers rörelsemönster med mera. Optisk rörelseanalys är den teknik som finns mest idag, men de systemen är dyra och saknar lämplig mjukvara för klinisk användning. En forskargrupp vid centrum för medicinsk teknik och strålningsfysik (CMTS) forskning och utvecklings avdelning (MT-FoU) vid Norrlands universitetssjukhus har sedan 2007 jobbat med en produktidé som bygger på att skapa ett nytt mobilt system för rörelseanalys som kan användas i medicinska undersökningar. Ett Arduino pro mini kort samt ett 9-axligt prototypkort som består av MPU-6000 och en magnetometer HMC5883L är anskaffat för att tillverka ett system i detta syfte. Syftet med projektet har varit att skapa ett verktyg som kan samla in rörelsemönster för att sedan presentera resultatet i ett diagram. Systemet skulle kunna samla in data från en sensor som inkluderar en 3D-accelerometer ett 3D-gyroskop och en 3D magnetometer för att därefter skicka det vidare till en dator där mätdata presenteras visuellt och sparas undan i en textfil. En viktig detalj att ta hänsyn till vid konstruktionen av det nya systemet var att konstruktionen gjordes med hjälp av billiga standardkomponenter och kretskort. Projektet har genomförts och några testmätningar har gjorts. Ett resultat sparades undan i en textfil och ett diagram har tagits fram som beskriver ett lårs rörelsemönster vid normal gång.