The Global Positioning System (GPS) and an Inertial Navigation System (INS)are two basic navigation systems. Due to their complementary characters in manyaspects, a GPS/INS integrated navigation system has been a hot research topic inthe recent decade. Both advantages and disadvantages of each individual systemare analyzed. The Micro Electrical Mechanical Sensors (MEMS) successfully solved theproblems of price, size and weight with the traditional INS. Therefore they arecommonly applied in GPS/INS integrated systems. The biggest problem ofMEMS is the large sensor errors, which rapidly degrade the navigationperformance in an exponential speed. By means of different methods, i.e.autoregressive model, Gauss-Markov process, Power Spectral Density and AllanVariance, we analyze the stochastic errors within the MEMS sensors. Real testson a MEMS based inertial measurement unit for each method are carried out. Theresults show that different methods give similar estimates of stochastic errorsources. These error coefficients can be used further in the Kalman filter for betternavigation performance and in the Doppler frequency estimate for fasteracquisition after the GPS signal outage. Three levels of GPS/IMU integration structures, i.e. loose, tight and ultra tightGPS/IMU navigation, are introduced with a brief analysis of each character. Theloose integration principles are given with detailed equations as well as the basicINS navigation principles. The Extended Kalman Filter (EKF) is introduced as the basic data fusionalgorithm, which is also the core of the whole navigation system to be presented.The kinematic constraints of land vehicle navigation, i.e. velocity constraint andheight constraint, are presented. These physical constraints can be used asadditional information to further reduce the navigation errors. The theoreticalanalysis of the Kalman filter with constraints are given to show the improvementon the navigation performance. As for the outliers in practical applications, theequivalent weight is introduced to adaptively reduce the influence on positioningaccuracy. A detailed implementation process of the GPS/IMU integration system is given.Based on the system model, we show the propagation of position standard errorswith the tight integration structure under different scenarios. Even less than 4observable satellites can contribute to the integrated system. Especially 2 satellitescan maintain the orientation errors at a reasonable level due to the benefit of thetight integration. A real test with loose integration structure is carried out, and theEKF performance as well as the physical constraints are analyzed in detail. Also atest with random outliers at the resolution level is carried out to show theeffectiveness of the equivalent weight. Finally some suggestions on future researchare proposed. / <p>QC 20111006</p>

Children have the same birthrights as adults. Nobody can restrict them or take it away. Children can not realize their birthrights, for their disability. This explains the reason, why children are most vulnerable and undefended members of our society. In this research, the constraint against children is described as negative and progressive social phenomenon. Actually, it is hard to evaluate gauge of this phenomenon and stop it is almost impossible. The official statistics do not reveal current situation and problems. For instance the psychical constraint is not registered at all in Lithuania.

Les effets délétères sur la santé de certaines expositions professionnelles, prises indépendamment, ont été observés dans un large nombre d’études. Pourtant, la prévalence et l'impact de multi-exposition ou co-exposition à des diverses nuisances ont plus rarement été explorée, malgré le caractère ubiquitaire de nombreuses nuisances. Par conséquent, l’étude de multi-exposition/co-exposition dans le cadre professionnel est considérée comme un enjeu majeur de la recherche épidémiologique en santé au travail. Une revue systématique de la littérature concernant le secteur de l’agriculture a été réalisé en s'appuyant sur le titre, le résumé, et le texte intégral des 36.404 articles originaux grâce à 5 bases de données reconnues et 2 sources de données nord-américaines complémentaires. Les résultats des 15 articles inclus suggèrent que l’exposition aux multiples chimiques est significativement associée au risque de maladies respiratoires, de cancers, de dommages sur l’ADN et les cytogénétiques. L’exposition aux multiples physiques a été associée à une augmentation du risque de perte d'audition, tandis que la co-exposition aux facteurs physiques et biomécaniques a été associée à un risque accru de troubles musculo-squelettiques. Aucune étude n'a exploré la co-exposition professionnelle à des facteurs chimiques et physiques, ainsi qu'à la co-exposition professionnelle à des facteurs chimiques et biomécaniques. Les résultats de cette revue de la littérature indiquent la nécessité l’évaluer la prévalence de l’exposition professionnel à des multiples nuisances en France. Les multiple/co-expositions aux agents neurotoxiques chimiques(ANCs) et aux contraintes physiques intenses (CPIs) ont ainsi été analysées chez 5587 hommes ouvriers français des secteurs de l'agriculture, de l’industrie manufacturière, et de la construction à partir de l’enquête nationale transversale SUMER 2010. Environ 6% des ouvriers étaient co-exposés aux ANCs et CPIs dans les trois secteurs étudiés (p = 0,29). La multi-exposition aux CPIs était plus nettement plus fréquente (35%, p <0,001) que la multi-exposition aux ANCs (2%, p <0,001) chez les hommes de trois secteurs. Ces recherches mettent en évidence la nécessité de conduire davantage d’études liées à multi-exposition/coexposition professionnelle. Elles seront essentielles pour améliorer la sécurité au travail et permettre la surveillance et la prévention risques et des maladies professionnelles. / A wide range of studies has demonstrated the relationships between diverse types of occupational exposures,taken independently, and adverse health outcomes. Yet, the prevalence and impact of multiple occupational exposures or co-exposures have rarely been explored despite the ubiquity of numerous hazards. Therefore, multiple occupational exposures/co-exposures and their impact on health are considered as a major challenge of epidemiologic research inthe occupational health and safety area. A systematic review concerning the agriculture sector was carried out based on the titles, abstracts and fulltexts screening of 36,404 initial articles from 5 well-known databases and 2 North American complementary sources. The findings from the 15 papers finally included suggested that multiple chemical exposures were significantly associated with an increased risk of respiratory diseases, cancers, DNA and cytogenetic damages. Multiple physical exposures were shown to increase the risk of hearing loss while co-exposures to physical and biomechanical hazardswere associated with an increased risk of musculoskeletal disorders. However, no studies included in the systematic review explored either occupational co-exposures to both physical and chemical factors or occupational co-exposures to biomechanical and chemical factors.The results described in the systematic review raised the necessity to conduct further studies multipleoccupational exposures and co-exposures among workers. Therefore, multiple occupational exposures and coexposures’ prevalences to chemical neurotoxic agents (CNAs) and intense physical constraints (IPCs) were examined among 5,587 French male blue-collar workers (BCWs) in the agriculture, manufacturing, and construction sectors based on the cross-sectional and national SUMER 2010 survey. About 6% of male BCWs were co-exposed to IPCs andCNAs in these three sectors (p=0.29). Multiple exposures to IPCs was predominantly observed (35%, p <0.001), while multiple exposures to CNAs was much lower (2%, p <0.001) among male BCWs in three sectors.The findings highlight the necessity to carry out further studies on multiple occupational exposures/coexposures to diverse hazards and their impact on workers’ health. These further researches are required to improve occupational safety and the efficiency of health care surveillance and occupational disease prevention.