1,982,808 research outputs found
Quantitative assessment of human motion using video motion analysis
In the study of the dynamics and kinematics of the human body, a wide variety of technologies was developed. Photogrammetric techniques are well documented and are known to provide reliable positional data from recorded images. Often these techniques are used in conjunction with cinematography and videography for analysis of planar motion, and to a lesser degree three-dimensional motion. Cinematography has been the most widely used medium for movement analysis. Excessive operating costs and the lag time required for film development coupled with recent advances in video technology have allowed video based motion analysis systems to emerge as a cost effective method of collecting and analyzing human movement. The Anthropometric and Biomechanics Lab at Johnson Space Center utilizes the video based Ariel Performance Analysis System to develop data on shirt-sleeved and space-suited human performance in order to plan efficient on orbit intravehicular and extravehicular activities. The system is described
Tracking and data system support for Surveyor mission 5, volume 3
Surveyor 5 tracking and data system activities evaluated from planning to final flight stage
Probe design
Outer planetary probe designs consider mission characteristics, structural configuration, delivery mode, scientific payload, environmental extremes, mass properties, and the launch vehicle and spacecraft interface
Method for making a hot wire anemometer and product thereof
A hot wire anemometer probe is described that includes a ceramic body supporting two conductive rods parallel to each other. The body has a narrow edge surface from which the rods protrude. A probe wire is welded to the rods and extends along the edge surface. A ceramic adhesive is used to secure the probe wire to the surface so that the probe wire is rigid. A method for fabricating the probe is also described in which the body is molded and precisely shaped by machining techniques before the probe wires are installed
Paired-angle-rotation scanning optical coherence tomography forward-imaging probe
We report a novel forward-imaging optical coherence tomography (OCT), needle-probe paired-angle-rotation scanning OCT (PARS-OCT) probe. The probe uses two rotating angled gradient-index lenses to scan the output OCT probe beam over a wide angular arc (∼19° half-angle) of the region forward of the probe. Among other advantages, this probe design is readily amenable to miniaturization and is capable of a variety of scan modes, including volumetric scans. To demonstrate the advantages of the probe design, we have constructed a prototype probe with an outer diameter of 1.65 mm and employed it to acquire four OCT images, with a 45° angle between adjacent images, of the gill structure of a Xenopus laevis tadpole. The system sensitivity was measured to be 93 dB by using the prototype probe with an illumination power of 450 μW on the sample. Moreover, the axial and the lateral resolutions of the probe are 9.3 and 10.3-12.5 μm, respectively
Droplet monitoring probe
A droplet monitoring system is disclosed for analysis of mixed-phase fluid flow in development of gas turbines. The system uses a probe comprising two electrical wires spaced a known distance apart and connected at one end to means for establishing a dc potential between the wires. A drop in the fluid stream momentarily contacting both wires simultaneously causes and electrical signal which is amplified, detected and counted
Dynamic error characteristics of touch trigger probes used with coordinate measuring machines
This paper discusses the dynamic error characteristics of touch trigger probes used with coordinate measuring machines. During the investigation, a number of important parameters have been identified, including measurement speed, probe longitude, approach distance, probe latitude, stylus length/stylus tip diameter, probe orientation, operating mode (scanning and nonscanning), scan pitch, preload spring force (gauging force), probe type, and the surface approach angle. This paper presents the detailed experimental design and the results obtained from the systematic experiments. These results have led to some useful recommendations for the reduction of the probe dynamic errors. Some of these recommendations included the selection of the optimum measurement speed, the setting of the preload spring force, and the choice of the probe type
NCAA FBI Probe
The article discusses the FBI probe as well as a list of other scandals that have risen from the investigation such as the debate as to whether to pay student athletes, the NCAA\u27s aim to stress academics over athletics, the NCAA\u27s transfer rules, and the one-and-done rule. The article also emphasizes the lack of emphasis on female athletes in the media and unfair treatment in relationship to Title XI
Dynamics and thermodynamics of a probe brane in the multicenter and rotating D3-brane background
We study the dynamics and thermodynamics of a probe D3-brane in the rotating
D3-brane background and in its extremal limit, which is a multicenter
configuration of D3-branes distributed uniformly on a disc. In the extremal
background, if the angular momentum of the probe does not vanish, the probe is
always bounced back at some turning point. When its angular momentum vanishes,
in the disc plane, the probe will be captured at the edge of the disc; in the
hyperplane orthogonal to the disc, the probe will be absorbed at the center of
the disc. In the non-extremal background, if the probe is in the hyperplane
orthogonal to the disc, it will be captured at the horizon; if the probe is
restricted in the disc plane, the probe will be bounced back at a turning
point, which is just the infinite red-shift hyperplane of the rotating
background, even when the angular momentum of the probe vanishes. The
thermodynamics of a relative static D3-brane probe is also investigated to the
rotating D3-brane source. Two critical points are found. One is just the
thermodynamically stable boundary of the source rotating D3-branes; the other
is related to the distance between the probe and the source, which can be
regarded as the mass scale in the corresponding super Yang-Mills theory. If the
probe is static, the second critical point occurs as the probe is at the
infinite red-shift hyperplane of the background. The relevance to the
thermodynamics of the super Yang-Mills theory is discussed briefly.Comment: Revtex, 16 pages, no figures, minor change
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