86 research outputs found
Biomechanical Evaluation of an Optical System for Quantitative Human Motion Analysis
An eight-camera Optitrack motion capture system was evaluated by performing static, linear dynamic, and angular dynamic calibrations using marker distances associated with upper and lower extremity gait and wheelchair models. Data were analyzed to determine accuracy and resolution within a defined capture volume using a standard Cartesian reference system. Two additional cameras along with AMASS and Visual3D (C-Motion, Inc., Germantown, MD) biomechanical modeling software were used to determine joint kinematics at the pelvis, hip, knee, and ankle of ten control subjects (mean age 21.5 ± 1.65 years). The same data were processed through Nexus (Vicon Motion Systems, Oxford, England) modeling software. The joint angle data was statistically compared between the two systems using a variance components model which determined the variability between maximum, minimum, and range values. Static accuracy ranged from 99.31% to 99.90%. Static resolution ranged from 0.04 ± 0.15 mm to 0.63 ± 0.15 mm at the 0.05 level of significance. The dynamic accuracy ranged from 94.82% to 99.77 %, and dynamic resolution ranged from 0.09 ± 0.26 mm to 0.61 ± 0.31 mm at the 0.05 level of significance. These values are comparable to those reported for a standard Vicon 524 (Vicon Motion Systems, Oxford, England) motion analysis system. Gait cycle maximum, minimum, and range values showed no significant difference when comparing Visual3D and Nexus at the pelvis, hip, and knee. Significant differences were seen at the tibia (rotation) and foot due to foot model variations between the two systems. The results support application of the lower cost Optitrack cameras and Visual3D software for 3D kinematic assessment of lower extremity motion during gait. Additional potential applications supported by these findings include other lower extremity models, assisted ambulation, and wheelchair mobility
Prioritizing Resources for Third-Year Medical Students
Prioritizing Resources for Third Year Medical Students To assess the effectiveness of using library surveys as a means of prioritizing resources for collection development. In the third year of medical undergraduate education, students are undergoing their core clinical rotations. During this period, exams in the core areas must be passed and therefore, access to relevant library resources is vital for successful completion. As part of their curriculum, students were able to accumulate additional points toward their final average by completing a survey, which assessed how library resources and availability, or lack thereof, affected their performance during this critical year. Since survey results have been previously collected for the purposes of quality improvement by the medical school, use of this data received IRB exemption. Short answer or Likert scale responses were thematically or quantitatively analyzed for those resources that students considered most beneficial. A modified version of Ose’s method for coding open-ended questions from web-based surveys was used for the analysis. Based on survey results, a final resource list conforming to a limited library budget, was generated and prioritized. After engagement of the medical school’s Learning Resources Committee, the requested resources were submitted for approval. The next group of third year medical students will determine the effectiveness of the newly acquired resources when a similar survey is deployed toward the end of the academic year
Motion Analysis Strategy Appropriate for 3D Kinematic Assessment of Children and Adults with Osteogenesis Imperfecta
Human motion analysis provides a quantitative means of assessing whole body and segmental motion of subjects with musculoskeletal pathologies. This chapter describes a low cost motion analysis appropriate for complete three-dimensional (3D) assessment of upper and lower extremity kinematics. The system has been designed to support lower cost outreach efforts that require accuracy and resolution on the order of classical fixed lot systems such as Vicon. The focus of this work addresses the assessment needs typically seen in adults and children with osteogenesis imperfect (OI) experiencing ambulatory and upper extremity challenges
ASSETS OF MODEL METRO STATION AND THEIR CRITICALITY
The paper deals with the identification of protected assets in the model metro station, which is a part of critical infrastructure in Praha; and with the identification of their criticality. A metro station is used by a lot of people and it involves many expensive components and devices with interdependences which form a system of systems. The system, its components and fittings are very vulnerable to damages from disasters of many kinds. The first step of ensuring metro station safety is the identification of basic metro assets which are important for safe metro operation and for human (employee and passengers) security and environment safety; and the other is determination of criticalities of considered assets with taking into account all relevant sources of hazards. These facts are input data for further processes which are important for safe metro operation under the different conditions
Archaeological Testing of 41BX1131 at O.R. Mitchell Dam, Bexar County, Texas
The Center for Archaeological Research contracted with the Simpson Group to conduct testing of 41BXl131, a prehistoric archaeological site located at the base of O. R. Mitchell Dam, on Medio Creek in southwest Bexar County. The purpose of testing was to determine whether or not the site would be impacted by construction of a spillway in the immediate area.
A pedestrian survey identified the extent of surface scatter. Subsequent shovel testing and backhoe trenching determined that the site had no depth, and consisted of a surface scatter only
DOMAINS OF RAILWAY TRAFFIC IN THE CZECH REPUBLIC, WHICH NEED THE SAFETY IMPROVEMENT
The paper analyses the railway accidents sources in the Czech Republic on the basis of knowledge on complex system behaviour. It derives seven categories of sources of railway accidents. The individual categories include the accident sources from the same field domain. These domains are: technical related to rail traffic vehicles; technical related to rail infrastructure and railway station; railway operation control – organizational causes; railway operation control – cyber causes; control of rail traffic vehicles; attack on the train; domain legislative and other. The results show that for railway traffic safety improvement, it is necessary to pay attention to all categories, and especially to these that lead to organizational accidents origination
The calculation method of interaction between metal atoms under influence of the radiation
A method of calculation of interatomic interaction potentials in the presence of ionized states has been developed. They have been obtained for the atoms with different ionization degree on example of aluminum. The Heine-Abarenkov-Animalu model potential form factors was employed. The form factor parameters of ionized atoms was determined on the base of the quantum defect method using the atomic-spectroscopy data. The potential of interatomic interaction for different charged states with different degree of ionization were determined
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Classification of oak vegetation in the Willamette Valley
A plant community classification was developed describing the comprehensive variation of oak vegetation currently occupying the Willamette Valley Ecoregion of western Oregon. Multivariate statistical analyses were used to classify field collected floristic and habitat data. Field sampling targeted minimally managed, homogenous vegetation stands with a significant oak component occupying at least 0.5 ha. Potential habitat locations were identified from local expert knowledge, data from The Nature Conservancy’s previous conservation planning efforts, and an interpretation of high resolution NAIP imagery. Potential oak habitats were digitized in a GIS and a random selection of sites stratifying significant environmental gradients was generated in order capture the range of oak habitat variability. Precise sample plot locations were predetermined and established at digitized stand centroids. Field sampling was based on relevé plot data collection methods and included ocular estimates of species cover. A total of 350 stands of oak vegetation were sampled over two field seasons. Two-way indicator species analysis (TWINSPAN) was used as an exploratory tool to identify potential patterns in species cover data and Detrended Correspondence Analysis (DCA) was used to delimit final plant community types. Nine vegetation classes were described from ordinations including seven forest / woodland types and two savanna
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